40Ar/39Ar ages of the AD 79 eruption of Vesuvius, Italy
Marvin A. Lanphere, Duane E. Champion, Leone Melluso, Vincenzo Morra, Annamaria Perrotta, Claudio Scarpati, Dario Tedesco, Andrew T. Calvert
2007, Bulletin of Volcanology (69) 259-263
The Italian volcano, Vesuvius, erupted explosively in AD 79. Sanidine from pumice collected at Casti Amanti in Pompeii and Villa Poppea in Oplontis yielded a weighted-mean 40Ar/39Ar age of 1925±66 years in 2004 (1σ uncertainty) from incremental-heating experiments of eight aliquants of sanidine. This is the calendar age of the eruption....
Estimating locations and total magnetization vectors of compact magnetic sources from scalar, vector, or tensor magnetic measurements through combined Helbig and Euler analysis
J. D. Phillips, M.N. Nabighian, D.V. Smith, Y. Li
2007, Conference Paper, SEG Technical Program Expanded Abstracts
The Helbig method for estimating total magnetization directions of compact sources from magnetic vector components is extended so that tensor magnetic gradient components can be used instead. Depths of the compact sources can be estimated using the Euler equation, and their dipole moment magnitudes can be estimated using a least...
Understanding the genetic effects of recent habitat fragmentation in the context of evolutionary history: Phylogeography and landscape genetics of a southern California endemic Jerusalem cricket (Orthoptera: Stenopelmatidae: Stenopelmatus)
Amy G. Vandergast, A.J. Bohonak, D.B. Weissman, Robert N. Fisher
2007, Molecular Ecology (16) 977-992
Habitat loss and fragmentation due to urbanization are the most pervasive threats to biodiversity in southern California. Loss of habitat and fragmentation can lower migration rates and genetic connectivity among remaining populations of native species, reducing genetic variability and increasing extinction risk. However, it may be difficult to separate the...
A virus in a fungus in a plant: Three-way symbiosis required for thermal tolerance
L.M. Marquez, R. S. Redman, R. J. Rodriguez, M.J. Roossinck
2007, Science (315) 513-515
A mutualistic association between a fungal endophyte and a tropical panic grass allows both organisms to grow at high soil temperatures. We characterized a virus from this fungus that is involved in the mutualistic interaction. Fungal isolates cured of the virus are unable to confer heat tolerance, but heat tolerance...
Northeast Kansas well tests oil, gas possibilities in Precambrian rocks
D. F. Merriam, K.D. Newell, J.H. Doveton, L.M. Magnuson, B.S. Lollar, W.M. Waggoner
2007, Oil & Gas Journal (105) 54-58
Tests for oil and gas prospects in Precambrian rocks in Northeast Kansas is currently being undertaken by WTW Operating LLC. It drilled in late 2005 the no.1 Wilson well with a depth of 5,772ft, 1,826ft into the Precambrian basement on a venture testing the possibility of oil and gas in...
Intra- and interlaboratory variability in acute toxicity tests with glochidia and juveniles of freshwater mussels (Unionidae)
N. Wang, T. Augspurger, M.C. Barnhart, Joseph R. Bidwell, W.G. Cope, F.J. Dwyer, S. Geis, I.E. Greer, C.G. Ingersoll, C.M. Kane, T.W. May, R. J. Neves, T.J. Newton, A.D. Roberts, D.W. Whites
2007, Environmental Toxicology and Chemistry (26) 2029-2035
The present study evaluated the performance and variability in acute toxicity tests with glochidia and newly transformed juvenile mussels using the standard methods outlined in American Society for Testing and Materials (ASTM). Multiple 48-h toxicity tests with glochidia and 96-h tests with juvenile mussels were conducted within a single laboratory...
Evidence of widespread natural reproduction by lake trout Salvelinus namaycush in the Michigan waters of Lake Huron
S.C. Riley, J.X. He, J.E. Johnson, T. P. O’Brien, J.S. Schaeffer
2007, Journal of Great Lakes Research (33) 917-921
Localized natural reproduction of lake trout Salvelinus namaycush in Lake Huron has occurred since the 1980s near Thunder Bay, Michigan. During 2004–2006, USGS spring and fall bottom trawl surveys captured 63 wild juvenile lake trout at depths ranging from 37–73 m at four of five ports in the Michigan waters of the...
Effects of somatostatin on the growth hormone-insulin-like growth factor axis and seawater adaptation of rainbow trout (Oncorhynchus mykiss)
J. Poppinga, J. Kittilson, S. D. McCormick, M.A. Sheridan
2007, Aquaculture (273) 312-319
Growth hormone (GH) has been shown to contribute to the seawater (SW) adaptability of euryhaline fish both directly and indirectly through insulin-like growth factor-1 (IGF-1). This study examined the role of somatostatin-14 (SS-14), a potent inhibitor of GH, on the GH-IGF-1 axis and seawater adaptation. Juvenile rainbow trout (Oncorhynchus mykiss)...
Construction and testing of a simple and economical soil greenhouse gas automatic sampler
D. Ginting, S.L. Arnold, N.S. Arnold, R.S. Tubbs
2007, Journal of Plant Nutrition (30) 1441-1454
Quantification of soil greenhouse gas emissions requires considerable sampling to account for spatial and/or temporal variation. With manual sampling, additional personnel are often not available to sample multiple sites within a narrow time interval. The objectives were to construct an automatic gas sampler and to compare the accuracy and precision...
Hydrogeologic controls on nitrate transport in a small agricultural catchment, Iowa
K. E. Schilling, M.D. Tomer, Y.-K. Zhang, T. Weisbrod, P. Jacobson, C.A. Cambardella
2007, Journal of Geophysical Research G: Biogeosciences (112)
Effects of subsurface deposits on nitrate loss in stream riparian zones are recognized, but little attention has been focused on similar processes occurring in upland agricultural settings. In this paper, we evaluated hydrogeologic controls on nitrate transport processes occurring in a small 7.6 ha Iowa catchment. Subsurface deposits in the...
Advantages of wet work for near-surface seismic reflection
R. D. Miller, R.D. Markiewicz, T.R. Rademacker, R. Hopkins, R.J. Rawcliffe, J. Paquin
2007, Conference Paper, SEG Technical Program Expanded Abstracts
Benefits of shallow water settings (0.1 to 0.5 m) are pronounced on shallow, high-resolution seismic reflection images and, for examples discussed here, range from an order of magnitude increased signal-to-noise ratio to resolution potential elevated by more than 8 times. Overall data quality of high-resolution seismic reflection data at three...
Mesogondolella and Jinogondolella (Conodonta): Multielement definition of the taxa that bracket the basal Guadalupian (Middle Permian Series) GSSP
L.L. Lambert, B. R. Wardlaw, C.M. Henderson
2007, Palaeoworld (16) 208-221
Multielement definitions are presented here for Mesogondolella and Jinogondolella based on species that bracket the basal Guadalupian (Middle Permian Series) GSSP. Distinctive apparatus characters that appear with the first Jinogondolella include several details of P2 element dimorphism and process bifurcation in S3 elements. The sequential expression of these multielement characters...
A comparative analysis of pre-Silurian crustal building blocks of the northern and the southern Appalachian orogen
J.P. Hibbard, C.R. van Staal, D.W. Rankin
2007, American Journal of Science (307) 23-45
The New York promontory serves as the divide between the northern and southern segments of the Appalachian orogen. Antiquated subdivisions, distinct for each segment, implied that they had lithotectonic histories that were independent of each other. Using new lithotectonic subdivisions we compare first order features of the pre-Silurian orogenic 'building...
Multiple stressors in amphibian communities: Effects of chemical contamination, bullfrogs, and fish
M.D. Boone, R. D. Semlitsch, E. E. Little, M. C. Doyle
2007, Ecological Applications (17) 291-301
A leading hypothesis of amphibian population declines is that combinations of multiple stressors contribute to declines. We examined the role that chemical contamination, competition, and predation play singly and in combination in aquatic amphibian communities. We exposed larvae of American toads (Bufo americanus), southern leopard frogs (Rana sphenocephala), and spotted...
Global-scale surface spectral variations on Titan seen from Cassini/VIMS
J. W. Barnes, R. H. Brown, L. Soderblom, B. J. Buratti, Christophe Sotin, S. Rodriguez, S. Le Mouelic, K. H. Baines, R. Clark, P. Nicholson
2007, Icarus (186) 242-258
We present global-scale maps of Titan from the Visual and Infrared Mapping Spectrometer (VIMS) instrument on Cassini. We map at 64 near-infrared wavelengths simultaneously, covering the atmospheric windows at 0.94, 1.08, 1.28, 1.6, 2.0, 2.8, and 5 ??m with a typical resolution of 50 km/pixel or a typical total integration...
Generation of fine hydromagmatic ash by growth and disintegration of glassy rinds
Larry G. Mastin
2007, Journal of Geophysical Research B: Solid Earth (112)
The deposits of mafic hydromagmatic eruptions are more fine grained and variable in vesicularity than dry magmatic deposits. Blocky, equant shapes of many hydromagmatic clasts also contrast with droplet, thread, and bubble wall morphology of dry magmatic fragments. Small (<∼180 μm), blocky hydromagmatic pyroclasts have traditionally been interpreted to result from...
Effects of nutrient enrichment on Prymnesium parvum population dynamics and toxicity: Results from field experiments, Lake Possum Kingdom, USA
D. L. Roelke, R.M. Errera, R. Kiesling, B.W. Brooks, J. P. Grover, L. Schwierzke, F. Urena-Boeck, J. Baker, J.L. Pinckney
2007, Aquatic Microbial Ecology (46) 125-140
Large fish kills associated with toxic populations of the haptophyte Prymnesium parvum occur worldwide. In the past 5 yr, incidences of P. parvum blooms in inland water bodies of Texas (USA) have increased dramatically, where cell densities in excess of 1 × 107 cells l–1 are typically observed. We conducted field experiments (Lake Possum Kingdom) during...
Genetic markers and the coregonid problem
W. Stott, T. N. Todd
Jankun M.Brzuzan P.Hliwa P.Luczynski M., editor(s)
2007, Conference Paper, Advances in Limnology
Coregonid fishes are the forage base in many ecosystems in the northern hemisphere and they have traditionally been part of commercial and native fisheries. Coregonids display extreme variability in morphology, life history, and behavior. Defining boundaries among coregonid taxa has been (and continues to be) the focus of many studies....
Predicting Secchi disk depth from average beam attenuation in a deep, ultra-clear lake
G.L. Larson, R.L. Hoffman, B.R. Hargreaves, R.W. Collier
2007, Hydrobiologia (574) 141-148
We addressed potential sources of error in estimating the water clarity of mountain lakes by investigating the use of beam transmissometer measurements to estimate Secchi disk depth. The optical properties Secchi disk depth (SD) and beam transmissometer attenuation (BA) were measured in Crater Lake (Crater Lake National Park, Oregon, USA)...
Forensic fingerprinting of oil-spill hydrocarbons in a methanogenic environment-Mandan, ND and Bemidji, MN
Frances D. Hostettler, Y. Wang, Y. Huang, W. Cao, Barbara A. Bekins, Colleen E. Rostad, C. F. Kulpa, Andrew E. Laursen
2007, Environmental Forensics (8) 139-153
In recent decades forensic fingerprinting of oil-spill hydrocarbons has emerged as an important tool for correlating oils and for evaluating their source and character. Two long-term hydrocarbon spills, an off-road diesel spill (Mandan, ND) and a crude oil spill (Bemidji, MN) experiencing methanogenic biodegradation were previously shown to be undergoing...
Chlorinated solvents in groundwater of the United States
M.J. Moran, J.S. Zogorski, P. J. Squillace
2007, Environmental Science & Technology (41) 74-81
Four chlorinated solvents-methylene chloride, perchloroethene (PCE), 1,1,1-trichloroethane, and trichloroethene (TCE)-were analyzed in samples of groundwater taken throughout the conterminous United States by the U.S. Geological Survey. The samples were collected between 1985 and 2002 from more than 5,000 wells. Of 55 volatile organic compounds (VOCs) analyzed in groundwater samples, solvents...
Diet niches of major forage fish in Lake Michigan
R. Douglas Hunter, J.F. Savino, L.M. Ogilvie
Jankun M.Brzuzan P.Hliwa P.Luczynski M., editor(s)
2007, Conference Paper, Advances in Limnology
A large complex of coregonine species historically dominated the fish community of Lake Michigan. The current species complex is simplified with one remaining coregonine, bloater (Coregonus hoyi), deepwater sculpin (Myoxocephalus thompsoni), slimy sculpin (Cottus cognatus), and two dominant invaders, alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax). To better understand...
Near infrared spectroscopic examination of charred pine wood, bark, cellulose and lignin: Implications for the quantitative determination of charcoal in soils
James B. Reeves III, Gregory W. McCarty, David W. Rutherford, Robert L. Wershaw
2007, Journal of Near Infrared Spectroscopy (15) 307-315
The objective of this research was to investigate the effect of charring on near infrared spectra of materials likely to be present in forest fires in order to determine the feasibility of determining charred carbon in soils. Four materials (cellulose, lignin, pine bark and pine wood) and char from these...
Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids
G.B. Lawrence, J.W. Sutherland, C.W. Boylen, S. W. Nierzwicki-Bauer, B. Momen, Barry P. Baldigo, H. A. Simonin
2007, Environmental Science & Technology (41) 93-98
Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is...
Soil nematode communities are ecologically more mature beneath late- than early-successional stage biological soil crusts
B.J. Darby, D.A. Neher, J. Belnap
2007, Applied Soil Ecology (35) 203-212
Biological soil crusts are key mediators of carbon and nitrogen inputs for arid land soils and often represent a dominant portion of the soil surface cover in arid lands. Free-living soil nematode communities reflect their environment and have been used as biological indicators of soil condition. In this study, we...
