Head-bobbing behavior in walking whooping cranes (Grus americana) and sandhill cranes (Grus canadensis)
Thomas W. Cronin, Matthew R. Kinloch, Glenn H. Olsen
2007, Journal of Ornithology (148) 563-569
Head-bobbing is a common and characteristic behavior of walking birds. While the activity could have a relatively minor biomechanical function, for balance and stabilization of gait, head-bobbing is thought to be primarily a visual behavior in which fixation of gaze alternates with a forward movement that generates visual flow. We...
Responses of pond-breeding amphibians to wildfire: Short-term patterns in occupancy and colonization
B. R. Hossack, P.S. Corn
2007, Ecological Applications (17) 1403-1410
Wildland fires are expected to become more frequent and severe in many ecosystems, potentially posing a threat to many sensitive species. We evaluated the effects of a large, stand-replacement wildfire on three species of pond-breeding amphibians by estimating changes in occupancy of breeding sites during the three years before and...
Near-fault peak ground velocity from earthquake and laboratory data
Art McGarr, Joe B. Fletcher
2007, Bulletin of the Seismological Society of America (97) 1502-1510
We test the hypothesis that peak ground velocity (PGV) has an upper bound independent of earthquake magnitude and that this bound is controlled primarily by the strength of the seismogenic crust. The highest PGVs, ranging up to several meters per second, have been measured at sites within a few kilometers...
Ground motion issues for seismic analysis of tall buildings: A status report
Y. Bozorgnia, K.W. Campbell, N. Luco, J.P. Moehle, F. Naeim, P. Somerville, T.Y. Yang
2007, Structural Design of Tall and Special Buildings (16) 665-674
The Pacific Earthquake Engineering Research Center (PEER) is coordinating a major multidisciplinary programme, the Tall Buildings Initiative (TBI), to address critical technical issues related to the design and analysis of new tall buildings located in coastal California. The authors of this paper, listed alphabetically, are involved in various research studies...
Transport and degradation of chlorofluorocarbons (CFCs) in the pyritic Rabis Creek aquifer, Denmark
K. Hinsby, Anker L. Højberg, P. Engesgaard, K.H. Jensen, F. Larsen, Niel Plummer, Eurybiades Busenberg
2007, Water Resources Research (43)
Vertical profiles of the chlorofluorocarbons CFC‐11, CFC‐12, and CFC‐113 penetrating aerobic and anaerobic parts of a shallow sandy aquifer show that the CFC gases are degraded in the <1 m thick transition zone from aerobic to anaerobic groundwater in a pyritic sand aquifer at Rabis Creek, Denmark. Two‐dimensional solute transport...
Neogene transpressional foreland basin development on the north side of the central alaska range, usibelli group and nenana gravel, tanana basin
K.D. Ridgway, E.E. Thoms, P.W. Layer, M.E. Lesh, J. M. White, S. V. Smith
2007, Special Paper of the Geological Society of America 507-547
Neogene strata of the Tanana basin provide a long-term record of a northwardpropagating, transpressional foreland-basin system related to regional shortening of the central Alaska Range and strike-slip displacement on the Denali fault system. These strata are ???2 km thick and have been deformed and exhumed in thrust faults that form...
Biogeographic affinity helps explain productivity-richness relationships at regional and local scales
S. Harrison, J.B. Grace
2007, Conference Paper, American Naturalist
The unresolved question of what causes the observed positive relationship between large-scale productivity and species richness has long interested ecologists and evolutionists. Here we examine a potential explanation that we call the biogeographic affinity hypothesis, which proposes that the productivity-richness relationship is a function of species' climatic tolerances that in...
Effect of daily oscillation in temperature and increased suspended sediment on growth and smolting in juvenile chinook salmon, Oncorhynchus tshawytscha
J. M. Shrimpton, Joseph D. Zydlewski, J.W. Heath
2007, Aquaculture (273) 269-276
We examined the effect of temperature oscillation and increased suspended sediment concentration on growth and smolting in juvenile ocean-type chinook salmon (Oncorhynchus tshawytscha). Fish were ponded on February 26; each treatment group had three replicates of 250 fish. Mean temperatures for the entire experiment were 12.3????C for all tanks with...
Rarity and diversity in forest ant assemblages of Great Smoky Mountains National Park
J.-P. Lessard, R.R. Dunn, C.R. Parker, N.J. Sanders
2007, Conference Paper, Southeastern Naturalist
We report on a systematic survey of the ant fauna occurring in hardwood forests in the Great Smoky Mountains National Park. At 22-mixed hardwood sites, we collected leaf-litter ant species using Winkler samplers. At eight of those sites, we also collected ants using pitfall and Malaise traps. In total, we...
Development of a mercury speciation, fate, and biotic uptake (BIOTRANSPEC) model: Application to Lahontan Reservoir (Nevada, USA)
N. Gandhi, S.P. Bhavsar, M.L. Diamond, James S. Kuwabara, Mark C. Marvin-DePasquale, David P. Krabbenhoft
2007, Environmental Toxicology and Chemistry (26) 2260-2273
A mathematically linked mercury transport, speciation, kinetic, and simple biotic uptake (BIOTRANSPEC) model has been developed. An extension of the metal transport and speciation (TRANSPEC) model, BIOTRANSPEC estimates the fate and biotic uptake of inorganic (Hg(II)), elemental (Hg(0)) and organic (MeHg) forms of mercury and their species in the dissolved,...
Precambrian accretionary history and phanerozoic structures-A unified explanation for the tectonic architecture of the nebraska region, USA
M.P. Carlson
2007, Conference Paper, Memoir of the Geological Society of America
The Phanerozoic history in Nebraska and adjacent regions contains many patterns of structure and stratigraphy that can be directly related to the history of the Precambrian basement rocks of the area. A process is proposed that explains the southward growth of North America during the period 1.8-1.6 Ga. A series...
Underwater microscope for measuring spatial and temporal changes in bed-sediment grain size
David M. Rubin, Henry Chezar, Jodi N. Harney, David J. Topping, Theodore S. Melis, Christopher R. Sherwood
2007, Sedimentary Geology (202) 402-408
For more than a century, studies of sedimentology and sediment transport have measured bed-sediment grain size by collecting samples and transporting them back to the laboratory for grain-size analysis. This process is slow and expensive. Moreover, most sampling systems are not selective enough to sample only the surficial grains that...
Remotely triggered earthquakes following moderate main shocks
Susan E. Hough
2007, Special Paper of the Geological Society of America (425) 73-86
Since 1992, remotely triggered earthquakes have been identified following large (M > 7) earthquakes in California as well as in other regions. These events, which occur at much greater distances than classic aftershocks, occur predominantly in active geothermal or volcanic regions, leading to theories that the earthquakes are triggered when...
Hazard assessment of the Tidal Inlet landslide and potential subsequent tsunami, Glacier Bay National Park, Alaska
G. F. Wieczorek, E.L. Geist, R.J. Motyka, M. Jakob
2007, Landslides (4) 205-215
An unstable rock slump, estimated at 5 to 10 × 106 m3, lies perched above the northern shore of Tidal Inlet in Glacier Bay National Park, Alaska. This landslide mass has the potential to rapidly move into Tidal Inlet and generate large, long-period-impulse tsunami waves. Field and photographic examination...
Influence of light and temperature on Prochlorococcus ecotype distributions in the Atlantic Ocean
E.R. Zinser, Z.I. Johnson, A. Coe, E. Karaca, D. Veneziano, S.W. Chisholm
2007, Limnology and Oceanography (52) 2205-2220
In a focused analysis of Prochlorococcus population structure in the western North Atlantic, we found that the relative abundances of ecotypes varied significantly with depth and, at seasonally stratified locations, with degree of vertical mixing. More limited regional variation was observed (e.g., Sargasso Sea, Gulf Stream, continental slope, and equatorial...
Effects of depth and crayfish size on predation risk and foraging profitability of a lotic crayfish
C.A. Flinders, D.D. Magoulick
2007, Journal of the North American Benthological Society (26) 767-778
We conducted field surveys and experiments to determine whether observed distributions of crayfish among habitats were influenced by differential resource availability, foraging profitability, and predation rates and whether these factors differed with crayfish size and habitat depth. We sampled available food resources (detritus and invertebrates) and shelter as rock substrate...
Geology of the Yucca Mountain site area, southwestern Nevada
W. R. Keefer, J.W. Whitney, D.C. Buesch
2007, Memoir of the Geological Society of America (199) 53-103
Yucca Mountain in southwestern Nevada is a prominent, irregularly shaped upland formed by a thick apron of Miocene pyroclastic-flow and fallout tephra deposits, with minor lava flows, that was segmented by through-going, large-displacement normal faults into a series of north-trending, eastwardly tilted structural blocks. The principal volcanic-rock units are the...
Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?
H.H. Welsh Jr., G. M. Fellers, A.J. Lind
2007, Journal of Herpetology (41) 469-482
Amphibian declines have been documented worldwide; however the vast majority are species associated with aquatic habitats. Information on the status and trends of terrestrial amphibians is almost entirely lacking. Here we use data collected across a 12-yr period (sampling from 1984-86 and from 1993-95) to address the question of whether...
Mid-Holocene change in types of degassing volcanoes, using indium in Antarctic ice as a tracer of volcanic source type
T. Hinkley, A. Matsumoto
2007, Geophysical Research Letters (34)
Proportions of trace metals in Antarctic ice samples indicate that the type of volcanoes that dominated atmospheric emissions changed at about the middle of the Holocene from relatively mafic, deep source volcanoes to more silicic, shallower-source volcanoes. We base this inference on the strong contrast in the abundances of the...
Fatty acid signatures of stomach oil and adipose tissue of northern fulmars (Fulmarus glacialis) in Alaska: Implications for diet analysis of Procellariiform birds
S.W. Wang, S.J. Iverson, A.M. Springer, Scott A. Hatch
2007, Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology (177) 893-903
Procellariiforms are unique among seabirds in storing dietary lipids in both adipose tissue and stomach oil. Thus, both lipid sources are potentially useful for trophic studies using fatty acid (FA) signatures. However, little is known about the relationship between FA signatures in stomach oil and adipose tissue of individuals or...
Differentiating pedogenesis from diagenesis in early terrestrial paleoweathering surfaces formed on granitic composition parent materials
S.G. Driese, L.G. Medaris Jr., M. Ren, Anthony C. Runkel, R.P. Langford
2007, Journal of Geology (115) 387-406
Unconformable surfaces separating Precambrian crystalline basement and overlying Proterozoic to Cambrian sedimentary rocks provide an exceptional opportunity to examine the role of primitive soil ecosystems in weathering and resultant formation of saprolite (weathered rock retaining rock structure) and regolith (weathered rock without rock structure), but many appear to have been...
Landward and eastward shift of Alaskan polar bear denning associated with recent sea ice changes
Anthony S. Fischbach, Steven C. Amstrup, David C. Douglas
2007, Polar Biology (30) 1395-1405
Polar bears (Ursus maritimus) in the northern Alaska region den in coastal areas and on offshore drifting ice. We evaluated changes in the distribution of polar bear maternal dens between 1985 and 2005, using satellite telemetry. We determined the distribution of maternal dens occupied by 89 satellite collared female polar...
The abundance and distribution of diamondoids in biodegraded oils from the San Joaquin Valley: Implications for biodegradation of diamondoids in petroleum reservoirs
Z. Wei, J.M. Moldowan, K. E. Peters, Y. Wang, W. Xiang
2007, Organic Geochemistry (38) 1910-1926
The biodegradability of diamondoids was investigated using a collection of crude oil samples from the San Joaquin Valley, California, that had been biodegraded to varying extent in the reservoir. Our results show that diamondoids are subjected to biodegradation, which is selective as well as stepwise. Adamantanes are generally more susceptible...
Multiple pathways for invasion of anurans on a Pacific island
M.T. Christy, J. A. Savidge, G.H. Rodda
2007, Diversity and Distributions (13) 598-607
Since 1937, thirteen species of non-indigenous anurans have made their way to Guam. Of these, at least six have established breeding populations. Various pathways led to the introduction of these species to the island. The only anuran intentionally introduced was Chaunus marinus (formerly Bufo marinus), which was brought to Guam...
Physically based estimation of soil water retention from textural data: General framework, new models, and streamlined existing models
John R. Nimmo, William N. Herkelrath, Luna Laguna
2007, Vadose Zone Journal (6) 766-773
Numerous models are in widespread use for the estimation of soil water retention from more easily measured textural data. Improved models are needed for better prediction and wider applicability. We developed a basic framework from which new and existing models can be derived to facilitate improvements. Starting from the assumption...
