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Page 2329, results 58201 - 58225

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Tidal asymmetry and residual circulation over linear sandbanks and their implication on sediment transport: a process-oriented numerical study
Rosario Sanay, George Voulgaris, John C. Warner
2007, Journal of Geophysical Research C: Oceans (112)
A series of process-oriented numerical simulations is carried out in order to evaluate the relative role of locally generated residual flow and overtides on net sediment transport over linear sandbanks. The idealized bathymetry and forcing are similar to those present in the Norfolk Sandbanks, North Sea. The importance of bottom...
Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska
A.D. Jolly, S.C. Moran, S.R. McNutt, D.B. Stone
2007, Journal of Volcanology and Geothermal Research (159) 326-342
The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6 km below...
Effects of precommercial thinning on snowshoe hares in Maine
J.A. Homyack, D.J. Harrison, W.B. Krohn
2007, Journal of Wildlife Management (71) 4-13
Snowshoe hares (Lepus americanus) are an important prey species and a dominant herbivore across much of their North American range, and researchers have questioned the influences of forestry practices that alter habitat for hares and the potential community-level effects on carnivores. We examined the effects of precommercial thinning (PCT) from...
Neoproterozoic diamictite-cap carbonate succession and δ13C chemostratigraphy from eastern Sonora, Mexico
Frank A. Corsetti, John H. Stewart, James W. Hagadorn
2007, Chemical Geology (237) 147-160
Despite the occurrence of Neoproterozoic strata throughout the southwestern U.S. and Sonora, Mexico, glacial units overlain by enigmatic cap carbonates have not been well-documented south of Death Valley, California. Here, we describe in detail the first glaciogenic diamictite and cap carbonate succession from Mexico, found in the Cerro Las Bolas...
Comparison of evapotranspiration rates for flatwoods and ridge citrus
X. Jia, A. Swancar, J.M. Jacobs, M.D. Dukes, K. Morgan
2007, Transactions of the ASABE (50) 83-94
Florida citrus groves are typically grown in two regions of the state: flatwoods and ridge. The southern flatwoods citrus area has poorly drained fine textured sands with low organic matter in the shallow root zone. Ridge citrus is located in the northern ridge citrus zone and has fine to coarse...
Spatial distribution of juvenile and adult female Tanner crabs (Chionoecetes bairdi) in a glacial fjord ecosystem: Implications for recruitment processes
J.K. Nielsen, S. James Taggart, Thomas C. Shirley, Jennifer Mondragon
2007, ICES Journal of Marine Science (64) 1772-1784
A systematic pot survey in Glacier Bay, Alaska, was conducted to characterize the spatial distribution of juvenile and adult female Tanner crabs, and their association with depth and temperature. The information was used to infer important recruitment processes for Tanner crabs in glaciated ecosystems. High-catch areas for juvenile and adult...
Restoration of waterbird habitats in Chesapeake Bay: Great expectations or Sisyphus revisited?
R.M. Erwin, R.A. Beck
2007, Waterbirds (30) 163-176
In the past half century, many waterbird populations in Chesapeake Bay have declined or shifted ranges, indicating major ecological changes have occurred. While many studies have focused on the problems associated with environmental degradation such as the losses of coastal wetlands and submerged vegetation, a number of restoration efforts have...
Characterising reef fish populations and habitats within and outside the US Virgin Islands Coral Reef National Monument: A lesson in marine protected area design
Mark E. Monaco, A. M. Friedlander, Chris Caldow, J.D. Christensen, C. Rogers, J. Beets, J. Miller, Rafe Boulon
2007, Fisheries Management and Ecology (14) 33-40
Marine protected areas are an important tool for management of marine ecosystems. Despite their utility, ecological design criteria are often not considered or feasible to implement when establishing protected areas. In 2001, the Virgin Islands Coral Reef National Monument (VICRNM) in St John, US Virgin Islands was established by Executive...
Accelerated uplift and magmatic intrusion of the Yellowstone caldera, 2004 to 2006
Wu-Lung Chang, Robert B. Smith, Charles Wicks, J.M. Farrell, C.M. Puskas
2007, Science (318) 952-956
The Yellowstone caldera began a rapid episode of ground uplift in mid-2004, revealed by Global Positioning System and interferometric synthetic aperture radar measurements, at rates up to 7 centimeters per year, which is over three times faster than previously observed inflation rates. Source modeling of the deformation data suggests an...
Inflammatory reaction to fabric collars from percutaneous antennas attached to intracoelomic radio transmitters implanted in harlequin ducks (Histrionicus histrionicus)
Daniel M. Mulcahy, K.A. Burek, Daniel Esler
2007, Journal of Avian Medicine and Surgery (21) 13-21
In wild birds implanted intracoelomically with radio transmitters, a synthetic fabric collar placed around the base of a percutaneous antenna is believed to function as a barrier to contamination of the coelom. We examined 13 fabric collars recovered from percutaneous antennas of radio transmitters implanted intracoelomically in harlequin ducks (Histrionicus...
Age and trophic position dominate bioaccumulation of mercury and organochlorines in the food web of Lake Washington
J.K. McIntyre, D.A. Beauchamp
2007, Science of the Total Environment (372) 571-584
Understanding the mechanisms of bioaccumulation in food webs is critical to predicting which food webs are at risk for higher rates of bioaccumulation that endanger the health of upper-trophic predators, including humans. Mercury and organochlorines were measured concurrently with stable isotopes of nitrogen and carbon in key fishes and invertebrates...
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...
Can parasites be indicators of free-living diversity? Relationships between species richness and the abundance of larval trematodes and of local benthos and fishes
R. F. Hechinger, K. D. Lafferty, T.C. Huspeni, A.J. Brooks, A. M. Kuris
2007, Oecologia (151) 82-92
Measuring biodiversity is difficult. This has led to efforts to seek taxa whose species richness correlates with the species richness of other taxa. Such indicator taxa could then reduce the time and cost of assessing the biodiversity of the more extensive community. The search for species richness correlations has yielded...
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...
Linking occurrence and fitness to persistence: Habitat-based approach for endangered Greater Sage-Grouse
Cameron L. Aldridge, Mark S. Boyce
2007, Ecological Applications (17) 508-526
Detailed empirical models predicting both species occurrence and fitness across a landscape are necessary to understand processes related to population persistence. Failure to consider both occurrence and fitness may result in incorrect assessments of habitat importance leading to inappropriate management strategies. We took a two-stage approach to identifying critical nesting...
Factors that influence the extraction of polycyclic aromatic hydrocarbons from coal
J. Xue, Gaisheng Liu, Z. Niu, C. L. Chou, C. Qi, Lingyun Zheng, H. Zhang
2007, Energy and Fuels (21) 881-890
Coal samples and carbonaceous mudstone were collected from the Huaibei coalfield, China, and experiments investigating the factors influencing the extraction of the sixteen US EPA (Environmental Protection Agency) priority polycyclic aromatic hydrocarbons (PAHs) were carried out. Different extraction times, solvents, and methods were used. Major interest was focused on finding...
Costimulatory receptors in jawed vertebrates: Conserved CD28, odd CTLA4 and multiple BTLAs
D. Bernard, J.D. Hansen, Pasquier L. Du, M.-P. Lefranc, A. Benmansour, P. Boudinot
2007, Developmental and Comparative Immunology (31) 255-271
CD28 family of costimulatory receptors is comprised of molecules with a single V-type extracellular Ig domain, a transmembrane and an intracytoplasmic region with signaling motifs. CD28 and cytotoxic T lymphocyte antigen-4 (CTLA4) homologs have been recently identified in rainbow trout. Other sequences similar to mammalian CD28 family members have now...
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....
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...
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...
Diel mercury-concentration variations in streams affected by mining and geothermal discharge
David A. Nimick, R. Blaine McCleskey, C.H. Gammons, Tom Cleasby, S.R. Parker
2007, Science of the Total Environment (373) 344-355
Diel variations of concentrations of unfiltered and filtered total Hg and filtered methyl Hg were documented during 24-h sampling episodes in water from Silver Creek, which drains a historical gold-mining district near Helena, Montana, and the Madison River, which drains the geothermal system of Yellowstone National Park. The concentrations of...
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)...
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...