Mineral resource of the month: barite
M. Michael Miller
2006, Geotimes (2006)
Also called barytes, barite forms in various geologic environments and is frequently found with both metallic and nonmetallic minerals. Most barite is produced by open-pit mining techniques, and most crude barite requires some upgrading to meet minimum purity or specific gravity levels....
Divergent patterns of abundance and age-class structure of headwater stream tadpoles in burned and unburned watersheds
B. R. Hossack, P.S. Corn, D.B. Fagre
2006, Canadian Journal of Zoology (84) 1482-1888
Wildfire is a potential threat to many species with narrow environmental tolerances like the Rocky Mountain tailed frog (Ascaphus montanus Mittleman and Myers, 1949), which inhabits a region where the frequency and intensity of wildfires are expected to increase. We compared pre- and post-fire counts of tadpoles in eight streams...
A structural equation model analysis of postfire plant diversity in California shrublands
J.B. Grace, Jon E. Keeley
2006, Ecological Applications (16) 503-514
This study investigates patterns of plant diversity following wildfires in fire‐prone shrublands of California, seeks to understand those patterns in terms of both local and landscape factors, and considers the implications for fire management. Ninety study sites were established following extensive wildfires in 1993, and 1000‐m2 plots were used to sample...
Isotopic evidence of nitrate sources and denitrification in the Mississippi River, Illinois
S.V. Panno, Keith C. Hackley, W.R. Kelly, H.-H. Hwang
2006, Journal of Environmental Quality (35) 495-504
Anthropogenic nitrate (NO3-) within the Mississippi-Atchafalaya River basin and discharge to the Gulf of Mexico has been linked to serious environmental problems. The sources of this NO 3- have been estimated by others using mass balance methods; however, there is considerable uncertainty in these estimates. Part of the uncertainty is...
Insect visitation and pollen deposition in an invaded prairie plant community
D.L. Larson, R.A. Royer, M.R. Royer
2006, Biological Conservation (130) 148-159
Invasive plants with large flowering displays have been shown to compete with native plants for pollinator services, often to the detriment of native plant fitness. In this study, we compare the pollinator communities and pollen deposited on stigmas of native plant species within and away from stands of the invasive...
Making connections for bird conservation: linking states, provinces & territories to important wintering and breeding grounds
P.J. Blancher, B. Jacobs, A. Couturier, C.J. Beardmore, R. Dettmers, Erica H. Dunn, W. Easton, Eduardo E. Inigo-Elias, T.D. Rich, K.V. Rosenberg, J. M. Ruth
2006, Partners in Flight Technical Series 4
To effectively conserve migratory landbirds, we need to be involved in conservation beyond our political borders. This has been a central tenet of Partners in Flight (PIF) since the initiative began in 1990 with a focus on Nearctic-Neotropical migrants. Implementation of this concept has also been fundamental to the...
Do geese fully develop brood patches? A histological analysis of lesser snow geese (Chen caerulescens caerulescens) and Ross's geese (C. rossii)
J.E. Jonsson, A. D. Afton, D.G. Homberger, W.G. Henk, R.T. Alisauskas
2006, Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology (176) 453-462
Most birds develop brood patches before incubation; epidermis and dermis in the brood patch region thicken, and the dermal connective tissue becomes increasingly vascularized and infiltrated by leukocytes. However, current dogma states that waterfowl incubate without modifications of skin within the brood patch region. The incubation periods of lesser snow...
Limestone fluidized bed treatment of acid-impacted water at the Craig Brook National Fish Hatchery, Maine, USA
P.L. Sibrell, B.J. Watten, T.A. Haines, B.W. Spaulding
2006, Aquacultural Engineering (34) 61-71
Decades of atmospheric acid deposition have resulted in widespread lake and river acidification in the northeastern U.S. Biological effects of acidification include increased mortality of sensitive aquatic species such as the endangered Atlantic salmon (Salmo salar). The purpose of this paper is to describe the development of a limestone-based fluidized...
Vaccination as a potential means to prevent plague in black-footed ferrets: Progress and continuing challenges
Tonie E. Rocke, Pauline Nol, Paul E. Marinari, J.S. Kreeger, Susan R. Smith, G.P. Andrews, A.W. Friedlander
2006, Scientific Investigations Report 2005-5293
This study was conducted to further assess the feasibility of vaccinating black-footed ferrets (Mustela nigripes) against plague (caused by the bacterium Yersinia pestis). On days 0 and 28, 17 postreproductive ferrets were immunized by subcutaneous injection with a recombinant fusion protein containing F1 and V antigens from Y. pestis. Another...
Timing of late Holocene surface rupture of the Wairau Fault, Marlborough, New Zealand
J. Zachariasen, K. Berryman, Rob Langridge, C. Prentice, M. Rymer, M. Stirling, P. Villamor
2006, New Zealand Journal of Geology and Geophysics (49) 159-174
Three trenches excavated across the central portion of the right-lateral strike-slip Wairau Fault in South Island, New Zealand, exposed a complex set of fault strands that have displaced a sequence of late Holocene alluvial and colluvial deposits. Abundant charcoal fragments provide age control for various stratigraphic horizons dating back to...
High-resolution stratigraphy of a Mississippi subdelta-lobe progradation in the Barataria Bight, north-central Gulf of Mexico
J. G. Flocks, N.F. Ferina, C. Dreher, J. L. Kindinger, D. M. FitzGerald, M.A. Kulp
2006, Journal of Sedimentary Research (76) 429-443
The coastal zone of southeastern Louisiana is the product of numerous cycles of progradation, abandonment, and marine transgression of the Mississippi River delta. Currently, the shoreline in the Barataria Bight is undergoing significant erosion and retreat, and understanding its evolution is crucial in stabilization efforts. This study uses an extensive...
Territoriality, site fidelity, and survivorship of willow flycatchers wintering in Costa Rica
T. J. Koronkiewicz, M. K. Sogge, Charles van Riper III, E. H. Paxton
2006, The Condor (108) 558-570
We studied wintering Willow Flycatchers (Empidonax traillii) in two seasonal freshwater wetland habitats in northwestern Costa Rica during five boreal winters, to determine habitat occupancy, overwinter and between-year site and territory fidelity, and the degree to which the sexes maintain and defend winter territories. Both males and females used agonistic...
Steroid estrogens, nonylphenol ethoxylate metabolites, and other wastewater contaminants in groundwater affected by a residential septic system on Cape Cod, MA
C.H. Swartz, S. Reddy, M.J. Benotti, H. Yin, L. B. Barber, Bruce J. Brownawell, R.A. Rudel
2006, Environmental Science & Technology (40) 4894-4902
Septic systems serve approximately 25% of U.S. households and may be an important source of estrogenic and other organic wastewater contaminants (OWC) to groundwater. We monitored several estrogenic OWC, including nonylphenol (NP), nonylphenol mono- and diethoxycarboxylates (NP1EC and NP2EC), the steroid hormones 17β-estradiol (E2), estrone (E1) and...
Structure of the San Andreas fault zone at SAFOD from a seismic refraction survey
J.A. Hole, T. Ryberg, G. S. Fuis, F. Bleibinhaus, A.K. Sharma
2006, Geophysical Research Letters (33)
Refraction traveltimes from a 46-km long seismic survey across the San Andreas Fault were inverted to obtain two-dimensional velocity structure of the upper crust near the SAFOD drilling project. The model contains strong vertical and lateral velocity variations from <2 km/s to ???6 km/s. The Salinian terrane west of the...
Antarctic climate cooling and response of diatoms in glacial meltwater streams
R.M.M. Esposito, S.L. Horn, Diane M. McKnight, M.J. Cox, M.C. Grant, S. A. Spaulding, P.T. Doran, K.D. Cozzetto
2006, Geophysical Research Letters (33)
To understand biotic responses to an Antarctic cooling trend diatom samples from glacial meltwater streams in the McMurdo Dry Valleys, the largest ice-free area in Antarctica. Diatoms are abundant in these streams, and 24 of 40 species have only been found in the Antarctic. The percentage of these Antarctic diatom...
Influence of metal exposure history on the bioaccumulation and subcellular distribution of aqueous cadmium in the insect Hydropsyche californica
D.J. Cain, D.B. Buchwalter, S. N. Luoma
2006, Environmental Toxicology and Chemistry (25) 1042-1049
The influence of metal exposure history on rates of aqueous Cd accumulation, elimination, and subcellular distribution was examined in the aquatic insect Hydropsyche californica. Specimens were obtained from a reference site and a metal‐contaminated site and returned to the laboratory where they were continuously exposed to aqueous...
Application of airborne thermal imagery to surveys of Pacific walrus
D. M. Burn, M.A. Webber, Mark S. Udevitz
2006, Wildlife Society Bulletin (34) 51-58
We conducted tests of airborne thermal imagery of Pacific walrus to determine if this technology can be used to detect walrus groups on sea ice and estimate the number of walruses present in each group. In April 2002 we collected thermal imagery of 37 walrus groups in the Bering Sea...
Phylogeography, phylogeny and hybridization in trichechid sirenians: Implications for manatee conservation
J. A. Vianna, Robert K. Bonde, S. Caballero, J. P. Giraldo, R. P. Lima, A. Clark, M. Marmontel, B. Morales-Vela, M. J. De Souza, L. Parr, M. A. Rodriguez-Lopez, A. A. Mignucci-Giannoni, J. A. Powell, F. R. Santos
2006, Molecular Ecology (15) 433-447
The three living species of manatees, West Indian (Trichechus manatus), Amazonian (Trichechus inunguis) and West African (Trichechus senegalensis), are distributed across the shallow tropical and subtropical waters of America and the western coast of Africa. We have sequenced the mitochondrial DNA control region in 330 Trichechus to compare their phylogeographic patterns. In T. manatus we...
Contact zone permeability at intrusion boundaries: New results from hydraulic testing and geophysical logging in the Newark Rift Basin, New York, USA
J.M. Matter, D.S. Goldberg, R. H. Morin, M. Stute
2006, Hydrogeology Journal (14) 689-699
Hydraulic tests and geophysical logging performed in the Palisades sill and the underlying sedimentary rocks in the NE part of the Newark Rift Basin, New York, USA, confirm that the particular transmissive zones are localized within the dolerite-sedimentary rock contact zone and within a narrow interval below this contact...
Re-seeding research will help in cheatgrass battle
Craig D. Allen
2006, BLM Snapshots (February 24, 2006) 2-2
Funding from the National Interagency Fire Center’s Joint Fire Science Program is helping researchers in northwestern Arizona determine whether several native grasses can be used to battle invasive cheatgrass following fire in ponderosa pine ecosystems....
Three-dimensional model for multi-component reactive transport with variable density groundwater flow
X. Mao, H. Prommer, D.A. Barry, C.D. Langevin, B. Panteleit, L. Li
2006, Environmental Modelling and Software (21) 615-628
PHWAT is a new model that couples a geochemical reaction model (PHREEQC-2) with a density-dependent groundwater flow and solute transport model (SEAWAT) using the split-operator approach. PHWAT was developed to simulate multi-component reactive transport in variable density groundwater flow. Fluid density in PHWAT depends not on only the concentration of...
Redox potential characterization and soil greenhouse gas concentration across a hydrological gradient in a Gulf coast forest
K. Yu, S.P. Faulkner, W.H. Patrick Jr.
2006, Chemosphere (62) 905-914
Soil redox potential (Eh), concentrations of oxygen (O2) and three greenhouse gases (CO2, CH4, and N2O) were measured in the soil profile of a coastal forest at ridge, transition, and swamp across a hydrological gradient. The results delineated a distinct boundary in soil Eh and O2 concentration between the ridge...
An evaluation of factors influencing pore pressure in accretionary complexes: Implications for taper angle and wedge mechanics
D.M. Saffer, B.A. Bekins
2006, Journal of Geophysical Research B: Solid Earth (111)
At many subduction zones, accretionary complexes form as sediment is off-scraped from the subducting plate. Mechanical models that treat accretionary complexes as critically tapered wedges of sediment demonstrate that pore pressure controls their taper angle by modifying basal and internal shear strength. Here, we combine a numerical model of groundwater...
A 3-decade dearth of deer (Odocoileus virginianus) in a wolf (Canis lupus)-dominated ecosystem
Michael E. Nelson, L. David Mech
2006, American Midland Naturalist (155) 373-382
Some 30 y after wolves (Canis lupus) were implicated in decimating wintering white-tailed deer (Odocoileus virginianus) in a 3000-km2 area of northeastern Minnesota, wintering deer still have not recolonized the area. From 1976 to 2004, we aerially radio-tracked wolves there during 250 h and recorded 2 deer (in 1985...
Sulfate deposition in subsurface regolith in Gusev crater, Mars
A. Wang, L.A. Haskin, S. W. Squyres, B.L. Jolliff, L. Crumpler, Ralf Gellert, C. Schroder, Kenneth E. Herkenhoff, J. Hurowitz, N.J. Tosca, W. H. Farrand, R. Anderson, A.T. Knudson
2006, Journal of Geophysical Research E: Planets (111)
Excavating into the shallow Martian subsurface has the potential to expose stratigraphic layers and mature regolith, which may hold a record of more ancient aqueous interactions than those expected under current Martian surface conditions. During the Spirit rover's exploration of Gusev crater, rover wheels were used to dig three trenches...
