Open Access. Powered by Scholars. Published by Universities.®

Geology Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of Nebraska - Lincoln

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 541 - 570 of 1807

Full-Text Articles in Geology

Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica, Christopher R. Fielding, Brian A. Blackstone, Tracy D. Frank, Zi Gui Apr 2012

Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica, Christopher R. Fielding, Brian A. Blackstone, Tracy D. Frank, Zi Gui

Department of Earth and Atmospheric Sciences: Faculty Publications

This paper provides documentation of unexpectedly high-reservoir-quality glaciomarine sands found in the Cenozoic succession beneath McMurdo Sound, Antarctica, as an analogue study for evaluations of hydrocarbon prospectivity in basins elsewhere. The Oligocene to Lower Miocene succession of the Victoria Land Basin, an extant portion of the West Antarctic Rift System, comprises diamictites, mudrocks, and sandstones with minor conglomerates. These lithologies are arranged in repetitive stacking patterns (cycles), interpreted to record repeated advance and retreat of glaciers into and out of the basin, with attendant eustatic and isostatic effects. Phases of ice retreat within the cycles comprise an array of mudrocks, …


Feeding Habitats Of The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi, In The Suwannee And Yellow Rivers, Florida, As Identified By Multiple Stable Isotope Analyses, Kenneth J. Sulak, J. J. Berg, M. Randall Mar 2012

Feeding Habitats Of The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi, In The Suwannee And Yellow Rivers, Florida, As Identified By Multiple Stable Isotope Analyses, Kenneth J. Sulak, J. J. Berg, M. Randall

United States Geological Survey: Staff Publications

Stable 13C, 15N, and 34S isotopes were analyzed to define the feeding habitats of Acipenser oxyrinchus desotoi in the Suwannee and Yellow River populations. For the majority (93.9%) of Suwannee sub adults and adults, 13C and 34S signatures indicate use of nearshore marine waters as primary winter feeding habitat, probably due to the limiting size of the Suwannee Sound estuary. In the Yellow River population, 13C isotope signatures indicate that adults remain primarily within Pensacola Bay estuary to feed in winter, rather than immigrating to the open Gulf of Mexico. A minor Suwannee River subset (6% of …


Heterogeneous Detection Probabilities For Imperiled Missouri River Fishes: Implications For Large-River Monitoring Programs, Joshua T. Schloesser, Craig P. Paukert, Wyatt J. Doyle, Tracy D. Hill, Kirk D. Steffensen, Vince H. Travnichek Mar 2012

Heterogeneous Detection Probabilities For Imperiled Missouri River Fishes: Implications For Large-River Monitoring Programs, Joshua T. Schloesser, Craig P. Paukert, Wyatt J. Doyle, Tracy D. Hill, Kirk D. Steffensen, Vince H. Travnichek

United States Geological Survey: Staff Publications

Occupancy modeling was used to determine (1) if detection probabilities (p) for 7 regionally imperiled Missouri River fishes (Scaphirhynchus albus, Scaphirhynchus platorynchus, Cycleptus elongatus, Sander canadensis, Macrhybopsis aestivalis, Macrhybopsis gelida, and Macrhybopsis meeki) differed among gear types (i.e. stationary gill nets, drifted trammel nets, and otter trawls), and (2) how detection probabilities were affected by habitat (i.e. pool, bar, and open water), longitudinal position (five 189 to 367 rkm long segments), sampling year (2003 to 2006), and season (July 1 to October 30 and October 31 to June 30). Adult, large-bodied fishes were …


Habitat And Prey Availability Attributes Associated With Juvenile And Early Adult Pallid Sturgeon Occurrence In The Missouri River, Usa, Bryan D. Spindler, Steven R. Chipps, Robert A. Klumb, Brian D. S. Graeb, Michael C. Wimberly Mar 2012

Habitat And Prey Availability Attributes Associated With Juvenile And Early Adult Pallid Sturgeon Occurrence In The Missouri River, Usa, Bryan D. Spindler, Steven R. Chipps, Robert A. Klumb, Brian D. S. Graeb, Michael C. Wimberly

United States Geological Survey: Staff Publications

The pallid sturgeon Scaphirhynchus albus is a federally endangered species native to the Missouri and lower Mississippi Rivers, USA. As part of recovery efforts, over 360 000 pallid sturgeon have been stocked into the Missouri River since 1994, and a standardized, long-term monitoring program was initiated in 2003. Understanding the distribution and habitat requirements of juvenile and early adult pallid sturgeon (fork length <720 mm, age <10 yr) is an important goal of the monitoring and recovery programs. In this study, we collected information on habitat characteristics and prey availability from the upper Missouri River along the Nebraska-South Dakota border and compared these attributes between capture (present) and non-capture (absent) locations (N = 59). To evaluate the relative influence of habitat and prey availability on pallid sturgeon occurrence, we examined several candidate models using an informationtheoretic approach. A prey availability model had the most support and included site-specific information on Diptera and Ephemeroptera abundance. A habitat-based model showed that juveniles and early adults were found in relatively deeper water and avoided areas where bottom velocities were greater than 1.2 m s−1. Although not as well supported as the prey-effects model (evidence ratio = 6.4), habitat features also provided a plausible model for predicting occurrence. The models developed here could be used to evaluate pallid sturgeon habitat potential in the Missouri River basin and help guide future monitoring and conservation management of this endangered species.


Strategies For Wildlife Disease Surveillance, Jonathan M. Sleeman, Christopher J. Brand, Scott D. Wright Jan 2012

Strategies For Wildlife Disease Surveillance, Jonathan M. Sleeman, Christopher J. Brand, Scott D. Wright

United States Geological Survey: Staff Publications

Epidemiologic surveillance is defined by the Centers for Disease Control and Prevention (CDC) as the "ongoing systematic and continuous collection, analysis, and interpretation of health data': The objective of surveillance is to generate data for rapid response to the detection of a disease of concern to apply prevention, control, or eradication measures as well as to evaluate such interventions. This is distinct from disease monitoring, which usually does not involve a particular response to disease detection.

Surveillance for wildlife diseases has increased in importance due to the emergence and re-emergence of wildlife diseases that are threats to human, animal, and …


Sea-Level History Of Past Interglacial Periods From Uranium-Series Dating Of Corals, Curaçao, Leeward Antilles Islands, Daniel R. Muhs, John M. Pandolfi, Kathleen R. Simmons, R. Randall Schumann Jan 2012

Sea-Level History Of Past Interglacial Periods From Uranium-Series Dating Of Corals, Curaçao, Leeward Antilles Islands, Daniel R. Muhs, John M. Pandolfi, Kathleen R. Simmons, R. Randall Schumann

United States Geological Survey: Staff Publications

Curaçao has reef terraces with the potential to provide sea-level histories of interglacial periods. Ages of the Hato (upper) unit of the “Lower Terrace” indicate that this reef dates to the last interglacial period, Marine Isotope Stage (MIS) 5.5. On Curaçao, this high sea stand lasted at least 8000 yr (~126 to ~118 ka). Elevations and age of this reef show that late Quaternary uplift rates on Curaçao are low, 0.026–0.054 m/ka, consistent with its tectonic setting. Ages of ~200 ka for corals from the older Cortalein unit of the Lower Terrace correlate this reef to MIS 7, with paleo-sea …


Soil Genesis On The Island Of Bermuda In The Quaternary: The Importance Of African Dust Transport And Deposition, Daniel R. Muhs, James R. Budahn, Joseph M. Prospero, Gary Skipp, Stanley R. Herwitz Jan 2012

Soil Genesis On The Island Of Bermuda In The Quaternary: The Importance Of African Dust Transport And Deposition, Daniel R. Muhs, James R. Budahn, Joseph M. Prospero, Gary Skipp, Stanley R. Herwitz

United States Geological Survey: Staff Publications

The origin of terra rossa, red or reddish-brown, clay-rich soils overlying high-purity carbonate substrates, has intrigued geologists and pedologists for decades. Terra rossa soils can form from accumulation of insoluble residues during dissolution of the host limestones, addition of volcanic ash, or addition of externally derived, long-range-transported (LRT) aeolian particles. We studied soils and paleosols on high-purity, carbonate aeolianites of Quaternary age on Bermuda, where terra rossa origins have been debated for more than a century. Potential soil parent materials on this island include sand-sized fragments of local volcanic bedrock, the LRT, fine-grained (µm) component of distal loess from the …


East Versus West: Organic Contaminant Differences In Brown Pelican (Pelecanus Occidentalis) Eggs From South Carolina, Usa And The Gulf Of California, Mexico, Stacy S. Vander Pol, Daniel W. Anderson, Patrick G.R. Jodice, Joyce E. Stuckey Jan 2012

East Versus West: Organic Contaminant Differences In Brown Pelican (Pelecanus Occidentalis) Eggs From South Carolina, Usa And The Gulf Of California, Mexico, Stacy S. Vander Pol, Daniel W. Anderson, Patrick G.R. Jodice, Joyce E. Stuckey

United States Geological Survey: Staff Publications

Brown pelicans (Pelecanus occidentalis) were listed as endangered in the United States in 1970, largely due to reproductive failure and mortality caused by organochlorine contaminants, such as DDT. The southeast population, P.o. carolinensis, was delisted in 1985, while the west coast population, P.o. californicus, was not delisted until 2009. As fish-eating coastal seabirds, brown pelicans may serve as a biomonitors. Organic contaminants were examined in brown pelican eggs collected from the Gulf of California in 2004 and South Carolina in 2005 using gas chromatography/mass spectrometry (GC/MS). Contaminants were compared using all individual data as well as …


Strontium Isotope Systematics Of Mixing Groundwater And Oil-Field Brine At Goose Lake In Northeastern Montana, Usa, Zell E. Peterman, Joanna N. Thamke, Kiyoto Futa, Todd M. Preston Jan 2012

Strontium Isotope Systematics Of Mixing Groundwater And Oil-Field Brine At Goose Lake In Northeastern Montana, Usa, Zell E. Peterman, Joanna N. Thamke, Kiyoto Futa, Todd M. Preston

United States Geological Survey: Staff Publications

Groundwater, surface water, and soil in the Goose Lake oil field in northeastern Montana have been affected by Cl- rich oil-field brines during long-term petroleum production. Ongoing multidisciplinary geochemical and geophysical studies have identified the degree and local extent of interaction between brine and groundwater. Fourteen samples representing groundwater, surface water, and brine were collected for Sr isotope analyses to evaluate the usefulness of 87Sr/86Sr in detecting small amounts of brine. Differences in Sr concentrations and 87Sr/86Sr are optimal at this site for the experiment. Strontium concentrations range from 0.13 to 36.9 mg/L, …


Critique On The Use Of The Standardized Avian Acute Oral Toxicity Test For First Generation Anticoagulant Rodenticides, Nimish B. Vyas, Barnett A. Rattner Jan 2012

Critique On The Use Of The Standardized Avian Acute Oral Toxicity Test For First Generation Anticoagulant Rodenticides, Nimish B. Vyas, Barnett A. Rattner

United States Geological Survey: Staff Publications

Avian risk assessments for rodenticides are often driven by the results of standardized acute oral toxicity tests without regards to a toxicant’s mode of action and time course of adverse effects. First generation anticoagulant rodenticides (FGARs) generally require multiple feedings over several days to achieve a threshold concentration in tissue and cause adverse effects. This exposure regimen is much different than that used in the standardized acute oral toxicity test methodology. Median lethal dose values derived from standardized acute oral toxicity tests underestimate the environmental hazard and risk of FGARs. Caution is warranted when FGAR toxicity, physiological effects, and pharmacokinetics …


Climate Change And Infectious Disease Dynamics, Raina K. Plowright, Paul C. Cross, Gary M. Tabor, Emily Almberg, Leslie Bienen, Peter J. Hudson Jan 2012

Climate Change And Infectious Disease Dynamics, Raina K. Plowright, Paul C. Cross, Gary M. Tabor, Emily Almberg, Leslie Bienen, Peter J. Hudson

United States Geological Survey: Staff Publications

The International Panel on Climate Change has made an unequivocal case that the earth's climate is changing in profound ways, and that human activities are contributing significantly to climate disruption (IPCC 2007). The weight of evidence demonstrates warming global temperatures, changing patterns of precipitation, and increasing climate variability, with more extreme events. Thus, the physical underpinnings of ecology are changing, with pervasive effects on disease dynamics. Interactions among environment, hosts, and pathogens drive disease processes, and climate change will influence every interaction in this triad, directly and indirectly.


Wildlife Toxicology: Environmental Contaminants And Their National And International Regulation, K. Christiana Grim, Anne Fairbrother, Barnett A. Rattner Jan 2012

Wildlife Toxicology: Environmental Contaminants And Their National And International Regulation, K. Christiana Grim, Anne Fairbrother, Barnett A. Rattner

United States Geological Survey: Staff Publications

Wildlife toxicology is the study of potentially harmful effects of toxic agents in wild animals, focusing on amphibians, reptiles, birds, and mammals. Fish and aquatic invertebrates are not usually included as part of wildlife toxicology since they fall within the field of aquatic toxicology, but collectively both disciplines often provide inSight into one another and both are integral parts of ecotoxicology (Hoffman et al. 2003). It entails monitoring, hypothesis testing, forensics, and risk assessment; encompasses molecular through ecosystem responses and various research venues (laboratory, mesocosm, field); and has been shaped by chemical use and misuse, ecological mishaps, and biomedical research. …


Sorta Situ: The New Reality Of Management Conditions For Wildlife Populations In The Absence Of "Wild" Spaces, Barbara A. Wolfe, Roberto F. Aguilar, A. Alonso Aguirre, Glenn H. Olsen, Evan S. Blumer Jan 2012

Sorta Situ: The New Reality Of Management Conditions For Wildlife Populations In The Absence Of "Wild" Spaces, Barbara A. Wolfe, Roberto F. Aguilar, A. Alonso Aguirre, Glenn H. Olsen, Evan S. Blumer

United States Geological Survey: Staff Publications

The rate of species loss today is approaching catastrophic levels. Scientists project that over the next two decades, more than 1 million species of plants and animals will become extinct. E.O. Wilson has estimated that "the rate ofloss may exceed 50,000 a year, 137 a day ... this rate, while horrendous, is actually the minimal estimate, based on the species/area relationship alone" (Kellert and Wilson 1993, p. 16; Aguirre 2009). Ever-expanding communities, strained natural resources, changes in land use, and other anthropogenic drivers are compromising ecosystems and rapidly changing the landscape and the availability of "wild" spaces.


Agricultural Drought Monitoring In Kenya Using Evapotranspiration Derived From Remote Sensing And Reanalysis Data, Michael T. Marshall, Christopher Funk, Joel Michaelsen Jan 2012

Agricultural Drought Monitoring In Kenya Using Evapotranspiration Derived From Remote Sensing And Reanalysis Data, Michael T. Marshall, Christopher Funk, Joel Michaelsen

United States Geological Survey: Staff Publications

More than half of the people in sub-Saharan Africa live on less than US$ 1.25 per day, and nearly 30% do not receive sufficient nourishment to maintain daily health (UN, 2009a). These figures are expected to rise as a result of the recent global financial crisis that has led to an increase in food prices. Food for Peace (FFP), the program that administers more than 85% of U.S. international food aid, recently reported that the seven largest recipient countries of food aid worldwide are in sub-Saharan Africa (FFP, 2010). In Kenya, the fifth largest recipient of food aid from FFP …


Three-Dimensional Hydrostratigraphy Of The Platte River Valley Near Ashland, Nebraska: Results From Helicopter Electromagnetic (Hem) Mapping In The Eastern Nebraska Water Resources Assessment (Enwra), P. R. Hanson, Jesse T. Korus, Dana Divine Jan 2012

Three-Dimensional Hydrostratigraphy Of The Platte River Valley Near Ashland, Nebraska: Results From Helicopter Electromagnetic (Hem) Mapping In The Eastern Nebraska Water Resources Assessment (Enwra), P. R. Hanson, Jesse T. Korus, Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Evolution With Depth From Detrital To Authigenic Smectites In Sediments From And-2a Drill Core (Mcmurdo Sound, Antarctica), Francesco Iacoviello, Giovanna Giorgetti, Fernando Nieto, Isabella Turbanti Memmi Jan 2012

Evolution With Depth From Detrital To Authigenic Smectites In Sediments From And-2a Drill Core (Mcmurdo Sound, Antarctica), Francesco Iacoviello, Giovanna Giorgetti, Fernando Nieto, Isabella Turbanti Memmi

ANDRILL Research and Publications

We have examined the nature and origin of smectites in glaciomarine sediments of the AND-2A drill core (McMurdo Sound, Antarctica) by means of X-ray diffraction (XRD) analyses on the clay fraction, field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM) observations and SEM-EDS microanalyses on smectite particles. Relying on the smectite variation throughout the drill core it was possible to split the sequence into three units. Smectites throughout the core are either detrital or authigenic. Detrital smectites are close to montmorillonite-beidellite in composition while newly-formed smectites frequently have higher Fe-Mg contents and intermediate compositions between the saponite and nontronite …


Hurricane Disturbance And Recovery Of Energy Balance, Co2 Fluxes And Canopy Structure In A Mangrove Forest Of The Florida Everglades, Jordan G. Barr, Vic Engel, Thomas J. Smith, José D. Fuentes Jan 2012

Hurricane Disturbance And Recovery Of Energy Balance, Co2 Fluxes And Canopy Structure In A Mangrove Forest Of The Florida Everglades, Jordan G. Barr, Vic Engel, Thomas J. Smith, José D. Fuentes

United States Geological Survey: Staff Publications

Eddy covariance (EC) estimates of carbon dioxide (CO2) fluxes and energy balance are examined to investigate the functional responses of a mature mangrove forest to a disturbance generated by Hurricane Wilma on October 24, 2005 in the Florida Everglades. At the EC site, high winds from the hurricane caused nearly 100% defoliation in the upper canopy and widespread tree mortality. Soil temperatures down to −50 cm increased, and air temperature lapse rates within the forest canopy switched from statically stable to statically unstable conditions following the disturbance. Unstable conditions allowed more efficient transport of water vapor and CO2 from …


Three-Dimensional Hydrostratigraphy Of The Sprague, Nebraska Area: Results From Helicopter Electromagnetic (Hem) Mapping For The Eastern Nebraska Water Resources Assessment (Enwra), Dana Divine, Jesse T. Korus Jan 2012

Three-Dimensional Hydrostratigraphy Of The Sprague, Nebraska Area: Results From Helicopter Electromagnetic (Hem) Mapping For The Eastern Nebraska Water Resources Assessment (Enwra), Dana Divine, Jesse T. Korus

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Assessment Of Coal Geology, Resources, And Reserves In The Montana Powder River Basin, Jon E. Haacke, David C. Scott, Lee M. Osmonson, James A. Luppens, Paul E. Pierce, Jay A. Gunderson Jan 2012

Assessment Of Coal Geology, Resources, And Reserves In The Montana Powder River Basin, Jon E. Haacke, David C. Scott, Lee M. Osmonson, James A. Luppens, Paul E. Pierce, Jay A. Gunderson

United States Geological Survey: Publications

The purpose of this report is to summarize geology, coal resources, and coal reserves in the Montana Powder River Basin (MTPRB) assessment area in southeastern Montana. This report represents the fourth assessment area within the Powder River Basin to be evaluated in the continuing U.S. Geological Survey regional coal assessment program.

There are four active coal mines in the MTPRB assessment area: the Spring Creek and Decker Mines, both near Decker; the Rosebud Mine, near Colstrip; and the Absaloka Mine, west of Colstrip. During 2011, coal production from these four mines totaled approximately 36 million short tons (MST). A fifth …


Copper Pellets Simulating Oral Exposure To Copper Ammunition: Absence Of Toxicity In American Kestrels (Falco Sparverius), J. Christian Franson, Lesanna L. Lahner, Carol U. Meteyer, Barnett A. Rattner Jan 2012

Copper Pellets Simulating Oral Exposure To Copper Ammunition: Absence Of Toxicity In American Kestrels (Falco Sparverius), J. Christian Franson, Lesanna L. Lahner, Carol U. Meteyer, Barnett A. Rattner

United States Geological Survey: Staff Publications

To evaluate the potential toxicity of copper

(Cu) in raptors that may consume Cu bullets, shotgun

pellets containing Cu, or Cu fragments as they feed on

wildlife carcasses, we studied the effects of metallic Cu

exposure in a surrogate, the American kestrel (Falco

sparverius). Sixteen kestrels were orally administered

5 mg Cu/g body mass in the form of Cu pellets

(1.18–2.00 mm in diameter) nine times during 38 days and

10 controls were sham gavaged on the same schedule. With

one exception, all birds retained the pellets for at least 1 h,

but most (69%) regurgitated pellets during …


Mapping Recent Decadal Climate Variations In Precipitation And Temperature Across Eastern Africa And The Sahel, Christopher Funk, Joel Michaelsen, Michael T. Marshall Jan 2012

Mapping Recent Decadal Climate Variations In Precipitation And Temperature Across Eastern Africa And The Sahel, Christopher Funk, Joel Michaelsen, Michael T. Marshall

United States Geological Survey: Staff Publications

This chapter presents a novel interpolation approach that combines long-term mean satellite observations, station data, and topographic fields to produce grids of climate normals and trends. The approach was developed by the Climate Hazard Group (CHG) at the University of California, Santa Barbara (UCSB), to support food security analyses for the U.S. Agency for International Development’s (USAID) Famine Early Warning Systems Network (FEWS NET). The resulting FEWS NET Climatology (FCLIM) combines moving window regressions (MWRs) with geostatistical interpolation (kriging). Satellite and topographic fields often exhibit strong local correlations with in situ measurements of air temperature and rainfall. The FCLIM method …


Guidebook To The Geology Of The Platte River Valley Between Duncan And Schuyler, Nebraska, P.R. Hanson, Robert Matthew Joeckel, Aaron R. Young, Dana Divine, Jesse T. Korus Dr. Jan 2012

Guidebook To The Geology Of The Platte River Valley Between Duncan And Schuyler, Nebraska, P.R. Hanson, Robert Matthew Joeckel, Aaron R. Young, Dana Divine, Jesse T. Korus Dr.

Conservation and Survey Division: Faculty and Staff Publications

The Platte River is considered to be a classic example of a braided stream, that is, a comparatively shallow stream with a high width:depth ratio.


Rinded Iron-Oxide Concretions: Hallmarks Of Altered Siderite Masses Of Both Early And Late Diagenetic Origin, David Loope, Richard Kettler, Karrie A. Weber, Nathan L. Hinrichs, Derek T. Burgess Jan 2012

Rinded Iron-Oxide Concretions: Hallmarks Of Altered Siderite Masses Of Both Early And Late Diagenetic Origin, David Loope, Richard Kettler, Karrie A. Weber, Nathan L. Hinrichs, Derek T. Burgess

Department of Earth and Atmospheric Sciences: Faculty Publications

Iron-bearing concretions are valuable records of oxidation states of subsurface waters, but the first concretions to form can be altered drastically during later diagenetic events. Distinctive concretions composed of heavy rinds of iron oxide that surround iron-poor, mud-rich cores are common along bases of fluvial cross-bed sets of the Cretaceous Dakota Formation, Nebraska, USA. Concretion rinds thicken inward and cores contain 46 to 89% void space. Millimeter-scale spherosiderites are abundant in palaeosols that developed in floodplain facies. Evolution of rinded concretions began when intraformational clasts were eroded from sideritic soils, transported, abraded and deposited in river channels. Alteration of siderite …


Three Geologic Cross Sections Across Portions Of Eastern Nebraska Showing Quaternary Lithologic Units And Stratigraphy Of Uppermost Bedrock, Jesse T. Korus, Dana Divine, P. R. Hanson, J. S. Dillon Jan 2012

Three Geologic Cross Sections Across Portions Of Eastern Nebraska Showing Quaternary Lithologic Units And Stratigraphy Of Uppermost Bedrock, Jesse T. Korus, Dana Divine, P. R. Hanson, J. S. Dillon

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nebraska Statewide Groundwater-Level Monitoring Report 2011, Jesse T. Korus Dr., Mark E. Burbach, Leslie M. Howard Jan 2012

Nebraska Statewide Groundwater-Level Monitoring Report 2011, Jesse T. Korus Dr., Mark E. Burbach, Leslie M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nebraska Statewide Groundwater-Level Monitoring Report 2012, A. R. Young, M. E. Burbach, J. T. Korus, L. M. Howard Jan 2012

Nebraska Statewide Groundwater-Level Monitoring Report 2012, A. R. Young, M. E. Burbach, J. T. Korus, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Gene Transcription In Sea Otters (Enhydra Lutris); Development Of A Diagnostic Tool For Sea Otter And Ecosystem Health, Lizabeth Bowen, A. Keith Miles, Michael Murray, Martin Haulena, Judy Tuttle, William Van Bonn, Lance Adams, James L. Bodkin, Brenda Ballachey, James A. Estes, M. Tim Tinker, Robin Keister, Jeffrey L. Stott Jan 2012

Gene Transcription In Sea Otters (Enhydra Lutris); Development Of A Diagnostic Tool For Sea Otter And Ecosystem Health, Lizabeth Bowen, A. Keith Miles, Michael Murray, Martin Haulena, Judy Tuttle, William Van Bonn, Lance Adams, James L. Bodkin, Brenda Ballachey, James A. Estes, M. Tim Tinker, Robin Keister, Jeffrey L. Stott

United States Geological Survey: Staff Publications

Gene transcription analysis for diagnosing or monitoring wildlife health requires the ability to distinguish pathophysiological change from natural variation. Herein, we describe methodology for the development of quantitative real-time polymerase chain reaction (qPCR) assays to measure differential transcript levels of multiple immune function genes in the sea otter (Enhydra lutris); sea otter-specific qPCR primer sequences for the genes of interest are defined. We establish a ‘reference’ range of transcripts for each gene in a group of clinically healthy captive and free-ranging sea otters. The 10 genes of interest represent multiple physiological systems that play a role in immuno-modulation, …


Do Bioclimate Variables Improve Performance Of Climate Envelope Models?, James I. Watling, Stephanie S. Romanach, David N. Bucklin, Carolina Speroterra, Laura A. Brandt, Leonard G. Pearlstine, Frank J. Mazzotti Jan 2012

Do Bioclimate Variables Improve Performance Of Climate Envelope Models?, James I. Watling, Stephanie S. Romanach, David N. Bucklin, Carolina Speroterra, Laura A. Brandt, Leonard G. Pearlstine, Frank J. Mazzotti

United States Geological Survey: Staff Publications

Climate envelope models are widely used to forecast potential effects of climate change on species distributions. A key issue in climate envelope modeling is the selection of predictor variables that most directly influence species. To determine whether model performance and spatial predictions were related to the selection of predictor variables, we compared models using bioclimate variables with models constructed from monthly climate data for twelve terrestrial vertebrate species in the southeastern USA using two different algorithms (random forests or generalized linear models), and two model selection techniques (using uncorrelated predictors or a subset of user-defined biologically relevant predictor variables). There …


Global Air Temperature Variability Independent Of Sea-Surface Temperature Influences, Andrew C. Comrie, Gregory J. Mccabe Jan 2012

Global Air Temperature Variability Independent Of Sea-Surface Temperature Influences, Andrew C. Comrie, Gregory J. Mccabe

United States Geological Survey: Staff Publications

Mean global surface air temperature (SAT) and sea surface temperature (SST) display substantial variability on timescales ranging from annual to multi-decadal. We review the key recent literature on connections between global SAT and SST variability. Although individual ocean influences on SAT have been recognized, the combined contributions of worldwide SST variability on the global SAT signal have not been clearly identified in observed data.Weanalyze these relations using principal components of detrended SST, and find that removing the underlying combined annual, decadal, and multi-decadal SST variability from the SAT time series reveals a nearly monotonic global warming trend in SAT since …


Gonadal Abnormalities In Frogs (Lithobates Spp.) Collected From Managed Wetlands In An Agricultural Region Of Nebraska, Usa, Diana M. Papoulias, Matt S. Schwarz, Lourdes Mena Jan 2012

Gonadal Abnormalities In Frogs (Lithobates Spp.) Collected From Managed Wetlands In An Agricultural Region Of Nebraska, Usa, Diana M. Papoulias, Matt S. Schwarz, Lourdes Mena

United States Geological Survey: Staff Publications

Nebraska’s Rainwater Basin (RWB) provides important wetland habitat for North American migratory birds. Concern exists that pesticide and nutrient runoff from surrounding row-crops enters wetlands degrading water quality and adversely affecting birds and wildlife. Frogs may be especially vulnerable. Plains leopard (Lithobates blairi) metamorphs from RWB wetlands with varying concentrations of pesticides were evaluated for a suite of biomarkers of exposure to endocrine active chemicals. Froglets had ovarian dysgenesis, high rates of testicular oocytes, and female-biased sex ratios however, there was no clear statistical association between pesticide concentrations and biomarkers. Data interpretation was hindered because timing and duration …