Stress-related hormones and genetic diversity in sea otters (Enhydra lutris)
Shawn E. Larson, Daniel H. Monson, Brenda E. Ballachey, Ronald J. Jameson, S.K. Wasser
2009, Marine Mammal Science (25) 351-372
Sea otters (Enhydra lutris) once ranged throughout the coastal regions of the north Pacific, but were extirpated throughout their range during the fur trade of the 18th and 19th centuries, leaving only small, widely scattered, remnant populations. All extant sea otter populations are believed to have experienced a population bottleneck...
Widespread increase of tree mortality rates in the Western United States
P. J. van Mantgem, N.L. Stephenson, J.C. Byrne, L.D. Daniels, J.F. Franklin, P.Z. Fule, M. E. Harmon, A.J. Larson, Joseph M. Smith, A.H. Taylor, T.T. Veblen
2009, Science (323) 521-524
Persistent changes in tree mortality rates can alter forest structure, composition, and ecosystem services such as carbon sequestration. Our analyses of longitudinal data from unmanaged old forests in the western United States showed that background (noncatastrophic) mortality rates have increased rapidly in recent decades, with doubling periods ranging from 17...
Shallow radar (SHARAD) sounding observations of the Medusae Fossae Formation, Mars
Lynn M. Carter, Bruce A. Campbell, Thomas R. Watters, Roger J. Phillips, Nathaniel E. Putzig, Ali Safaeinili, Jeffrey J. Plaut, Chris Okubo, Anthony F. Egan, Roberto Seu, Daniela Biccari, Roberto Orosei
2009, Icarus (199) 295-302
The SHARAD (shallow radar) sounding radar on the Mars Reconnaissance Orbiter detects subsurface reflections in the eastern and western parts of the Medusae Fossae Formation (MFF). The radar waves penetrate up to 580 m of the MFF and detect clear subsurface interfaces in two locations: west MFF between 150 and...
Exotic plant species associations with horse trails, old roads, and intact native communities in the Missouri Ozarks
E.D. Stroh, M.A. Struckhoff
2009, Natural Areas Journal (29) 50-56
We compared the extent to which exotic species are associated with horse trails, old roads, and intact communities within three native vegetation types in Ozark National Scenic Riverways, Missouri. We used a general linear model procedure and a Bonferroni multiple comparison test to compare exotic species richness, exotic to native...
A Mid-Late Quaternary loess-paleosol record in Simmons Farm in southern Illinois, USA
Hongfang Wang, C.C. Lundstrom, Z. Zhang, D.A. Grimley, W.L. Balsam
2009, Quaternary Science Reviews (28) 93-106
In unglaciated areas of the Mississippi Valley region, the typical full loess-paleosol succession contains the Modern Soil developed in Peoria Silt, weakly developed Farmdale Geosol developed in Roxana Silt, Sangamon Geosol developed in Loveland Silt, and Yarmouth Geosol developed in Crowley's Ridge Silt. Although a fifth loess called the Marianna...
Sedimentary basin effects in Seattle, Washington: Ground-motion observations and 3D simulations
Arthur Frankel, William Stephenson, David Carver
2009, Bulletin of the Seismological Society of America (99) 1579-1611
Seismograms of local earthquakes recorded in Seattle exhibit surface waves in the Seattle basin and basin-edge focusing of S waves. Spectral ratios of Swaves and later arrivals at 1 Hz for stiff-soil sites in the Seattle basin show a dependence on the direction to the earthquake, with earthquakes to the...
Characteristics of ground motion at permafrost sites along the Qinghai-Tibet railway
L. Wang, Z. Wu, Jielun Sun, Xiuying Liu, Z. Wang
2009, Soil Dynamics and Earthquake Engineering (29) 974-981
Based on 14 typical drilling holes distributed in the permafrost areas along the Qinghai-Tibet railway, the distribution of wave velocities of soils in the permafrost regions were determined. Using results of dynamic triaxial tests, the results of dynamic triaxiality test and time histories of ground motion acceleration in this area,...
The 1911 M ~6.6 Calaveras earthquake: Source parameters and the role of static, viscoelastic, and dynamic coulomb stress changes imparted by the 1906 San Francisco earthquake
D. I. Doser, K.B. Olsen, F. F. Pollitz, R.S. Stein, S. Toda
2009, Bulletin of the Seismological Society of America (99) 1746-1759
The occurrence of a right-lateral strike-slip earthquake in 1911 is inconsistent with the calculated 0.2-2.5 bar static stress decrease imparted by the 1906 rupture at that location on the Calaveras fault, and 5 yr of calculated post-1906 viscoelastic rebound does little to reload the fault. We have used all available...
How processing digital elevation models can affect simulated water budgets
E. L. Kuniansky, M.A. Lowery, B. G. Campbell
2009, Ground Water (47) 97-107
For regional models, the shallow water table surface is often used as a source/sink boundary condition, as model grid scale precludes simulation of the water table aquifer. This approach is appropriate when the water table surface is relatively stationary. Since water table surface maps are not readily available, the elevation...
Recent experimental data may point to a greater role for osmotic pressures in the subsurface
C. E. Neuzil, A.M. Provost
2009, Water Resources Research (45)
Uncertainty about the origin of anomalous fluid pressures in certain geologic settings has caused researchers to take a second look at osmosis, or flow driven by chemical potential differences, as a pressure‐generating process in the subsurface. Interest in geological osmosis has also increased because of an in situ experiment by...
Experimental infection of cliff swallows (Petrochelidon pyrrhonota) with varying doses of West Nile virus
P.T. Oesterle, N.M. Nemeth, Kaci K. VanDalen, H. Sullivan, K.T. Bentler, G.R. Young, R. G. McLean, L. Clark, C. Smeraski, Jeffrey S. Hall
2009, American Journal of Tropical Medicine and Hygiene (81) 1159-1164
Cliff swallows (Petrochelidon pyrrhonota) were inoculated with differing doses of West Nile virus (WNV) to evaluate their potential role as reservoir hosts in nature. Swallows often nest in large colonies in habitats and months associated with high mosquito abundance and early WNV transmission in North America. Additionally, cliff swallow diet...
Temporal latitudinal-gradient dynamics and tropical instability of deep-sea species diversity
Moriaki Yasuhara, G. Hunt, T. M. Cronin, H. Okahashi
2009, Proceedings of the National Academy of Sciences of the United States of America (106) 21717-21720
A benthic microfaunal record from the equatorial Atlantic Ocean over the past four glacial-interglacial cycles was investigated to understand temporal dynamics of deep-sea latitudinal species diversity gradients (LSDGs). The results demonstrate unexpected instability and high amplitude fluctuations of species diversity in the tropical deep ocean that are correlated with orbital-scale...
Simulating and understanding sand wave variation: A case study of the Golden Gate sand waves
F. Sterlini, S.J.M.H. Hulscher, D.M. Hanes
2009, Journal of Geophysical Research F: Earth Surface (114)
In this paper we present a detailed comparison between measured features of the Golden Gate sand wave field and the results of a nonlinear sand wave model. Because the Golden Gate sand waves exhibit large variation in their characteristics and in their environmental physics, this area gives us the opportunity...
A distal earthquake cluster concurrent with the 2006 explosive eruption of Augustine Volcano, Alaska
M. A. Fisher, N.A. Ruppert, R.A. White, Frederic H. Wilson, D. Comer, R. W. Sliter, F. L. Wong
2009, Tectonophysics (469) 25-36
Clustered earthquakes located 25 km northeast of Augustine Volcano began about 6 months before and ceased soon after the volcano's 2006 explosive eruption. This distal seismicity formed a dense cluster less than 5 km across, in map view, and located in depth between 11 km and 16 km. This seismicity was contemporaneous with sharply increased...
Isotopic composition of low-latitude paleoprecipitation during the Early Cretaceous
M.B. Suarez, Luis A. Gonzalez, Greg A. Ludvigson, F.J. Vega, J. Alvarado-Ortega
2009, Geological Society of America Bulletin (121) 1584-1595
The response of the hydrologic cycle in global greenhouse conditions is important to our understanding of future climate change and to the calibration of global climate models. Past greenhouse conditions, such as those of the Cretaceous, can be used to provide empirical data with which to evaluate climate models. Recent...
Thorium abundances on the Aristarchus plateau: Insights into the composition of the Aristarchus pyroclastic glass deposits
Justin Hagerty, D. J. Lawrence, B. R. Hawke, Lisa R. Gaddis
2009, Journal of Geophysical Research E: Planets (114)
Thorium (Th) data from the Lunar Prospector gamma ray spectrometer (LP‐GRS) are used to constrain the composition of lunar pyroclastic glass deposits on top of the Aristarchus plateau. Our goal is to use forward modeling of LP‐GRS Th data to measure the Th abundances on the plateau and then to...
Impact of a permanent El Niño (El Padre) and Indian Ocean Dipole in warm Pliocene climates
Sonali P. Shukla, Mark A. Chandler, Jeff Jonas, Linda E. Sohl, Ken Mankoff, Harry J. Dowsett
2009, Paleoceanography (24)
Pliocene sea surface temperature data, as well as terrestrial precipitation and temperature proxies, indicate warmer than modern conditions in the eastern equatorial Pacific and imply permanent El Niño–like conditions with impacts similar to those of the 1997/1998 El Niño event. Here we use a general circulation model to examine the...
Assessment of undiscovered oil and gas in the arctic
Donald L. Gautier, Kenneth J. Bird, Ronald R. Charpentier, Arthur Grantz, David W. Houseknecht, Timothy R. Klett, Thomas E. Moore, Janet K. Pitman, Christopher J. Schenk, John H. Schuenemeyer, Kai Sorensen, Marilyn E. Tennyson, Zenon C. Valin, Craig J. Wandrey
2009, Science (324) 1175-1179
Among the greatest uncertainties in future energy supply and a subject of considerable environmental concern is the amount of oil and gas yet to be found in the Arctic. By using a probabilistic geology-based methodology, the United States Geological Survey has assessed the area north of the Arctic Circle and...
Legacy effects of colonial millponds on floodplain sedimentation, bank erosion, and channel morphology, MID-Atlantic, USA
E.R. Schenk, C.R. Hupp
2009, Journal of the American Water Resources Association (45) 597-606
Many rivers and streams of the Mid-Atlantic Region, United States (U.S.) have been altered by postcolonial floodplain sedimentation (legacy sediment) associated with numerous milldams. Little Conestoga Creek, Pennsylvania, a tributary to the Susquehanna River and the Chesapeake Bay, is one of these streams. Floodplain sedimentation rates, bank erosion rates, and...
Acoustic estimates of abundance and distribution of spawning lake trout on Sheboygan Reef in Lake Michigan
D.M. Warner, R.M. Claramunt, J. Janssen, D.J. Jude, N. Wattrus
2009, Journal of Great Lakes Research (35) 147-153
Efforts to restore self-sustaining lake trout (Salvelinus namaycush) populations in the Laurentian Great Lakes have had widespread success in Lake Superior; but in other Great Lakes, populations of lake trout are maintained by stocking. Recruitment bottlenecks may be present at a number of stages of the reproduction process. To study...
Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus.
J.L. Zajicek, L. Brown, S.B. Brown, D. C. Honeyfield, J.D. Fitzsimons, D. E. Tillitt
2009, Journal of Aquatic Animal Health (21) 207-216
The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage...
An adaptive strategy for reducing feral cat predation on endangered Hawaiian birds
S.C. Hess, P.C. Banko, H. Hansen
2009, Pacific Conservation Biology (15) 56-64
Despite the long history of Feral Cats Felis catus in Hawai'i, there has been little research to provide strategies to improve control programmes and reduce depredation on endangered species. Our objective Was to develop a predictive model to determine how landscape features on Mauna Kea, such as habitat, elevation, and...
Sensitivity of system stability to model structure
G.R. Hosack, H.W. Li, P.A. Rossignol
2009, Ecological Modelling (220) 1054-1062
A community is stable, and resilient, if the levels of all community variables can return to the original steady state following a perturbation. The stability properties of a community depend on its structure, which is the network of direct effects (interactions) among the variables within the community. These direct effects...
Sulfate-rich eolian and wet interdune deposits, erebus crater, meridiani Planum, Mars
J.M. Metz, J.P. Grotzinger, D. M. Rubin, K.W. Lewis, S. W. Squyres, J.F. Bell
2009, Journal of Sedimentary Research (79) 247-264
This study investigates three bedrock exposures at Erebus crater, an ?? 300 m diameter crater approximately 4 km south of Endurance crater on Mars. These outcrops, called Olympia, Payson, and Yavapai, provide additional evidence in support of the dune-interdune model proposed for the formation of the deposits at the Opportunity...
Streamflow changes in Alaska between the cool phase (1947–1976) and the warm phase (1977–2006) of the Pacific Decadal Oscillation: The influence of glaciers
Glenn A. Hodgkins
2009, Water Resources Research (45)
Streamflow data from 35 stations in and near Alaska were analyzed for changes between the cool phase (1947–1976) and the warm phase (1977–2006) of the Pacific Decadal Oscillation. Winter, spring, and summer flow changes and maximum annual flow changes were different for glaciated basins (more than 10% glacier‐covered area) than...
