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2004

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Articles 3001 - 3030 of 4447

Full-Text Articles in Physical Sciences and Mathematics

Scwds Briefs: Volume 19, Number 4 (January 2004) Jan 2004

Scwds Briefs: Volume 19, Number 4 (January 2004)

Southeastern Cooperative Wildlife Disease Study: Publications


• A highly pathogenic avian influenza (HPAI) virus (H5N1) recently has been reported among domestic poultry in Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam. This virus also has been responsible for 23 confirmed human cases, including 18 deaths.
• U.S. Secretary of Agriculture Ann Veneman announced a “presumptive positive” case of bovine spongiform encephalopathy (BSE) in a dairy cow from the state of Washington.—Report on completed investigation.
• Proposed Rule in the Federal Register regarding a chronic wasting disease (CWD) herd certification program and interstate shipping requirements for captive deer and elk.
• Another BIG Year for …

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Generalized Geologic Map For Land-Use Planning: Fulton County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey Jan 2004

Generalized Geologic Map For Land-Use Planning: Fulton County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

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Generalized Geologic Map For Land-Use Planning: Livingston County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey Jan 2004

Generalized Geologic Map For Land-Use Planning: Livingston County, Kentucky, E. Glynn Beck, David A. Williams, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

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Magneto-Thermal Behavior Of A Granular Fecl2–Fe Heterostructure, Sarbeswar Sahoo, Christian Binek, Wolfgang Kleemann Jan 2004

Magneto-Thermal Behavior Of A Granular Fecl2–Fe Heterostructure, Sarbeswar Sahoo, Christian Binek, Wolfgang Kleemann

Christian Binek Publications

A granular system consisting of ferromagnetic single-domain Fe particles in an antiferromagnetic FeCl2 matrix was prepared by coevaporation in an ultra-high vacuum environment. The structural and magnetic properties were investigated by X-ray diffractometry and superconducting quantum interference device magnetometry, respectively. The heterostructure combines the properties of superparamagnetic Fe granules and the antiferromagnetism of the FeCl2 matrix. In addition, dipolar interaction-induced giant moments are observed below the Néel temperature of the FeCl2 matrix. The thermomagnetic properties of the giant moments are studied.

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Grouped Data, Gudmund R. Iversen Jan 2004

Grouped Data, Gudmund R. Iversen

Mathematics & Statistics Faculty Works

No abstract provided.

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An Agricultural Drought Risk-Assessment Model For Corn And Soybeans, Hong Wu, Kenneth G. Hubbard, Donald A. Wilhite Jan 2004

An Agricultural Drought Risk-Assessment Model For Corn And Soybeans, Hong Wu, Kenneth G. Hubbard, Donald A. Wilhite

Drought Mitigation Center: Faculty Publications

Copyright © 2004 Royal Meteorological Society. Published by Wiley InterScience. Used by permis-sion.

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An Operational Agricultural Drought Risk Assessment Model For Nebraska, Usa, Hong Wu, Donald A. Wilhite Jan 2004

An Operational Agricultural Drought Risk Assessment Model For Nebraska, Usa, Hong Wu, Donald A. Wilhite

Drought Mitigation Center: Faculty Publications

Drought is a common occurrence in Nebraska and agriculture is the primary economic sector affected. Because of repeated and widespread severe drought impacts, more emphasis on drought risk management is warranted. This study develops an agricultural drought risk assessment model using multivariate techniques. The model is specific to corn and soybeans and is able to assess real-time agricultural drought risk associated with crop yield losses at critical phenological stages prior to and during the growing season. The assessment results are presented in a Geographic Information System to provide a better visualization. This model provides information in a timely manner about …

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Recent Advances In Drought Monitoring, Mark D. Svoboda, Michael J. Hayes, Donald A. Wilhite, Tsegaye Tadesse Jan 2004

Recent Advances In Drought Monitoring, Mark D. Svoboda, Michael J. Hayes, Donald A. Wilhite, Tsegaye Tadesse

Drought Mitigation Center: Faculty Publications

Recent widespread, severe, and long-lasting droughts across North America have heightened awareness of and interest in how to better monitor drought and its impacts. Since its inception in 1999, the National Drought Mitigation Center (NDMC), United States Department of Agriculture (USDA) and NOAA’s Climate Prediction Center (CPC) and National Climatic Data Center (NCDC) have partnered to produce the weekly U.S. Drought Monitor (http://droug ht.unl.edu/m onitor/), a comprehensive drought assessment product based on a simple 5- category severity classification. On the heels of its widespread acceptance and usage, the NCDC, CPC, USDA, NDMC and scientists from Canada and Mexico have worked …

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Collaborative Design (Colldesign): A Real-Time Interactive Unified Modeling Language Tool, Surya Telikapalli Jan 2004

Collaborative Design (Colldesign): A Real-Time Interactive Unified Modeling Language Tool, Surya Telikapalli

Theses Digitization Project

This project extended COLLDESIGN, an interactive collaborative modeling tool that was developed by Mr. Hara Totapally. The initial version included a collaborative framework comprised of configurable client and server components. This project accomplished a complete implementation of the Class Diagram view. In addition, extending the framework, text messaging and audio conferencing features have been implemented to allow for real-time textual and audio communication between team members working on a particular project. VideoClient is the GUI of the application.

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Umbilical Cord: A System For Ubiquitous Computing, James Emory Warshawsky Jan 2004

Umbilical Cord: A System For Ubiquitous Computing, James Emory Warshawsky

Theses Digitization Project

Ubiquitous computing aims to make computing widely available, easy to use, and completely transparent to the user. Umbilical Cord is intended to be the first step in researching ubiquitous computing at CSUSB. It implements a model scalable network with a client-server architecture that features consistent user interaction and global access to user data. It is based on the Linux operating system which can be leveraged for future research due to the open nature of its source code. It also features a scalable network swap.

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Use Of Next Generation Weather Radar Data And Basin Disaggregation To Improve Continuous Hydrograph Simulations, Ziya Zhang, Victor Koren, Michael Smith, Seann Reed, David Wang Jan 2004

Use Of Next Generation Weather Radar Data And Basin Disaggregation To Improve Continuous Hydrograph Simulations, Ziya Zhang, Victor Koren, Michael Smith, Seann Reed, David Wang

United States Department of Commerce: Staff Publications

Currently, the river forecasting system deployed in each of 13 River Forecast Centers of the National Weather Service primarily uses lumped parameter models to generate hydrologic simulations. With the deployment of the weather surveillance radar 1988 Doppler radars, more and more precipitation data with high spatial and temporal resolution have become available for hydrologic modeling. Hydrologists inside and outside the National Weather Service are now investigating how to effectively use these data to enhance river-forecasting capabilities. In this paper, six years of continuously simulated hydrographs from an eight-subbasin model are compared to those from a single-basin (or lumped) model, both …

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Symmetric Representations Of Elements Of Finite Groups, Abeir Mikhail Kasouha Jan 2004

Symmetric Representations Of Elements Of Finite Groups, Abeir Mikhail Kasouha

Theses Digitization Project

This thesis demonstrates an alternative, concise but informative, method for representing group elements, which will prove particularly useful for the sporadic groups. It explains the theory behind symmetric presentations, and describes the algorithm for working with elements represented in this manner.

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Monitoring Polynuclear Aromatic Hydrocarbons In Aqueous Environments With Passive Low-Density Polyethylene Membrane Devices, Mark G. Carls, Larry G. Holland, Jeffrey W. Short, Ron A. Heintz, Stanley D. Rice Jan 2004

Monitoring Polynuclear Aromatic Hydrocarbons In Aqueous Environments With Passive Low-Density Polyethylene Membrane Devices, Mark G. Carls, Larry G. Holland, Jeffrey W. Short, Ron A. Heintz, Stanley D. Rice

United States Department of Commerce: Staff Publications

Low-density polyethylene membranes, typically filled with triolein, have been previously deployed as passive environmental samplers designed to accumulate nonpolar hydrophobic chemicals from water, sediments, and air. Hydrocarbons in such samplers, known as semipermeable membrane devices (SPMDs), diffuse through pores in the membranes and are trapped in the central hydrocarbon matrix, mimicking uptake by living organisms. Here, we describe laboratory and field verification that lowdensity polyethylene membrane devices (PEMDs) without triolein provide reliable, relatively inexpensive, time-integrated hydrocarbon sampling from water. For comparison, polynuclear aromatic hydrocarbon (PAH) uptake in SPMDs and pink salmon eggs also was studied. Total concentrations of PAH accumulated …

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Abundance Of Blue And Humpback Whales In The Eastern North Pacific Estimated By Capture-Recapture And Line-Transect Methods, John Calambokidis, Jay Barlow Jan 2004

Abundance Of Blue And Humpback Whales In The Eastern North Pacific Estimated By Capture-Recapture And Line-Transect Methods, John Calambokidis, Jay Barlow

United States Department of Commerce: Staff Publications

We estimated humpback and blue whale abundance from 1991 to 1997 off the west coast of the US. and Mexico comparing capture-recapture models based on photographically identified animals and line-transect methods from ship-based surveys. During photo-identification research we obtained 4,2 12 identifications of 824 humpback whales and 2,403 identifications of 908 blue whales primarily through non-systematic small-boat surveys along the coast of California, Oregon, and Washington. Line-transect surveys from NOAA ships in 1991, 1993, and 1996 covered approximately 39,000 km along the coast of Baja California, California, Oregon, and Washington out to 555 km from shore. The nearshore and clumped …

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Conceptual Model Builder, Chia-Yang Lin Jan 2004

Conceptual Model Builder, Chia-Yang Lin

Theses Digitization Project

Whenever one designs a new database system, an Entity-Relationship Diagram (ER diagram) is always needed to present the structure of this database. Using the graphically well-arranged ER Diagram helps you to easily understand the entities, attributes, domains, primary keys, foreign keys, constraints, and relationships inside a database. This data-modeling tool is an ideal choice for companies and developers.

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Holocene Loess Deposition And Soil Formation As Competing Processes, Matanuska Valley, Southern Alaska, Daniel R. Muhs, John P. Mcgeehin, Jossh Beann, Eric Fisher Jan 2004

Holocene Loess Deposition And Soil Formation As Competing Processes, Matanuska Valley, Southern Alaska, Daniel R. Muhs, John P. Mcgeehin, Jossh Beann, Eric Fisher

United States Geological Survey: Staff Publications

Although loess–paleosol sequences are among the most important records of Quaternary climate change and past dust deposition cycles, few modern examples of such sedimentation systems have been studied. Stratigraphic studies and 22 new accelerator mass spectrometry radiocarbon ages from the Matanuska Valley in southern Alaska show that loess deposition there began sometime after ~6500 14C yr B.P. and has continued to the present. The silts are produced through grinding by the Matanuska and Knik glaciers, deposited as outwash, entrained by strong winds, and redeposited as loess. Over a downwind distance of ~40 km, loess thickness, sand content, and sand-pluscoarse- …

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Corrigendum To ‘‘Radiocarbon Dating, Chronologic Framework, And Changes In Accumulation Rates Of Holocene Estuarine Sediments From Chesapeake Bay’’ [Quaternary Research 57 (2002) 58–70], Steven M. Colman, Pattie C. Baucom, John F. Bratton, Thomas M. Cronin, John P. Mcgeehin, Debra Willard, Andrew R. Zimmerman, Peter R. Vogt Jan 2004

Corrigendum To ‘‘Radiocarbon Dating, Chronologic Framework, And Changes In Accumulation Rates Of Holocene Estuarine Sediments From Chesapeake Bay’’ [Quaternary Research 57 (2002) 58–70], Steven M. Colman, Pattie C. Baucom, John F. Bratton, Thomas M. Cronin, John P. Mcgeehin, Debra Willard, Andrew R. Zimmerman, Peter R. Vogt

United States Geological Survey: Staff Publications

Because of an error in the calculation of bulk densities from water contents, the cumulative masses in Fig. 8 are too high by a factor of about 2. The actual correction depends to small degree on water content and ranges from 1.8 for a water content of 50% to 2.2 for a water content of 75%. The values for mass accumulation rates in the left two columns of Table 5 are also affected, but the ratios between pre- and post-settlement times are not. A revised version of that table is given below. None of the major conclusions of the paper …

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Limnological And Climatic Environments At Upper Klamath Lake, Oregon During The Past 45 000 Years, J. Platt Bradbury, Steven M. Colman, Walter E. Dean Jan 2004

Limnological And Climatic Environments At Upper Klamath Lake, Oregon During The Past 45 000 Years, J. Platt Bradbury, Steven M. Colman, Walter E. Dean

United States Geological Survey: Staff Publications

Upper Klamath Lake, in south-central Oregon, contains long sediment records with well-preserved diatoms and lithological variations that reflect climate-induced limnological changes. These sediment archives complement and extend high resolution terrestrial records along a north–south transect that includes areas influenced by the Aleutian Low and Subtropical High, which control both marine and continental climates in the western United States. The longest and oldest core collected in this study came from the southwest margin of the lake at Caledonia Marsh, and was dated by radiocarbon and tephrochronology to an age of about 45 ka. Paleolimnological interpretations of this core, based upon geochemical …

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Fine-Scale Structure Of The San Andreas Fault Zone And Location Of The Safod Target Earthquakes, C. Thurber, S. Roecker, H. Zhang, S. Baher, W. Ellsworth Jan 2004

Fine-Scale Structure Of The San Andreas Fault Zone And Location Of The Safod Target Earthquakes, C. Thurber, S. Roecker, H. Zhang, S. Baher, W. Ellsworth

United States Geological Survey: Staff Publications

We present results from the tomographic analysis of seismic data from the Parkfield area using three different inversion codes. The models provide a consistent view of the complex velocity structure in the vicinity of the San Andreas, including a sharp velocity contrast across the fault. We use the inversion results to assess our confidence in the absolute location accuracy of a potential target earthquake. We derive two types of accuracy estimates, one based on a consideration of the location differences from the three inversion methods, and the other based on the absolute location accuracy of ‘‘virtual earthquakes.’’ Location differences are …

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A Mechanical Model Of The San Andreas Fault And Safod Pilot Hole Stress Measurements, Jean Chéry, Mark D. Zoback, Stephen Hickman Jan 2004

A Mechanical Model Of The San Andreas Fault And Safod Pilot Hole Stress Measurements, Jean Chéry, Mark D. Zoback, Stephen Hickman

United States Geological Survey: Staff Publications

Stress measurements made in the SAFOD pilot hole provide an opportunity to study the relation between crustal stress outside the fault zone and the stress state within it using an integrated mechanical model of a transform fault loaded in transpression. The results of this modeling indicate that only a fault model in which the effective friction is very low (<0.1) through the seismogenic thickness of the crust is capable of matching stress measurements made in both the far field and in the SAFOD pilot hole. The stress rotation measured with depth in the SAFOD pilot hole (~28 ° ) appears to be a typical feature of a weak fault embedded in a strong crust and a weak upper mantle with laterally variable heat flow, although our best model predicts less rotation (15 ° ) than observed. Stress magnitudes predicted by our model within the fault zone indicate low shear stress on planes parallel to the fault but a very anomalous mean stress, approximately twice the lithostatic stress.

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Uranium-Series Coral Ages From The Us Atlantic Coastal Plain–The ‘‘80 Ka Problem’’ Revisited, John F. Wehmiller, Kathleen R. Simmons, Hai Cheng, R. Lawrence Edwards, Jamie Martin-Mcnaughton, Linda L. York, David E. Krantz, Chuan-Chou Shen Jan 2004

Uranium-Series Coral Ages From The Us Atlantic Coastal Plain–The ‘‘80 Ka Problem’’ Revisited, John F. Wehmiller, Kathleen R. Simmons, Hai Cheng, R. Lawrence Edwards, Jamie Martin-Mcnaughton, Linda L. York, David E. Krantz, Chuan-Chou Shen

United States Geological Survey: Staff Publications

Uranium series coral ages for emergent units from the passive continental margin US Atlantic Coastal Plain (ACP) suggest sea level above present levels at the end of marine oxygen isotope stage (MIS) 5, contradicting age-elevation relations based on marine isotopic or coral reef models of ice equivalent sea level. We have reexamined this problem by obtaining high precision 230Th/238U and 231Pa/235U thermal ionization mass spectrometric ages for recently collected and carefully cleaned ACPcorals, many in situ. We recognize samples that show no evidence for diagenesis on the basis of uranium isotopic composition and age …

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Persistence Of Pharmaceutical Compounds And Other Organic Wastewater Contaminants In A Conventional Drinking-Water-Treatment Plant, Paul E. Stackelberg, Edward T. Furlong, Michael T. Meyer, Steven D. Zaugg, Alden K. Henderson, Dori B. Reissman Jan 2004

Persistence Of Pharmaceutical Compounds And Other Organic Wastewater Contaminants In A Conventional Drinking-Water-Treatment Plant, Paul E. Stackelberg, Edward T. Furlong, Michael T. Meyer, Steven D. Zaugg, Alden K. Henderson, Dori B. Reissman

United States Geological Survey: Staff Publications

In a study conducted by the US Geological Survey and the Centers for Disease Control and Prevention, 24 water samples were collected at selected locations within a drinking-water-treatment (DWT) facility and from the two streams that serve the facility to evaluate the potential for wastewater-related organic contaminants to survive a conventional treatment process and persist in potable-water supplies. Stream-water samples as well as samples of raw, settled, filtered, and finished water were collected during low-flow conditions, when the discharge of effluent from upstream municipal sewage-treatment plants accounted for 37–67% of flow in stream 1 and 10–20% of flow in stream …

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Estimating Accumulation Rates And Physical Properties Of Sediment Behind A Dam: Englebright Lake, Yuba River, Northern California, Noah P. Snyder, David M. Rubin, Charles N. Alpers, Jonathan R. Childs, Jennifer A. Curtis, Lorraine E. Flint, Scott A. Wright Jan 2004

Estimating Accumulation Rates And Physical Properties Of Sediment Behind A Dam: Englebright Lake, Yuba River, Northern California, Noah P. Snyder, David M. Rubin, Charles N. Alpers, Jonathan R. Childs, Jennifer A. Curtis, Lorraine E. Flint, Scott A. Wright

United States Geological Survey: Staff Publications

Studies of reservoir sedimentation are vital to understanding scientific and management issues related to watershed sediment budgets, depositional processes, reservoir operations, and dam decommissioning. Here we quantify the mass, organic content, and grain-size distribution of a reservoir deposit in northern California by two methods of extrapolating measurements of sediment physical properties from cores to the entire volume of impounded material. Englebright Dam, completed in 1940, is located on the Yuba River in the Sierra Nevada foothills. A research program is underway to assess the feasibility of introducing wild anadromous fish species to the river upstream of the dam. Possible management …

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Grassland Vegetation And Bird Communities In The Southern Great Plains Of North America, Robert N. Chapman, David M. Engle, Ronald E. Masters, David M. Leslie Jr. Jan 2004

Grassland Vegetation And Bird Communities In The Southern Great Plains Of North America, Robert N. Chapman, David M. Engle, Ronald E. Masters, David M. Leslie Jr.

United States Geological Survey: Staff Publications

Structure and composition of vegetation and abundance of breeding birds in grasslands seeded to Old World bluestem (Bothriochloa ischmaeum) were compared to native mixed prairie in the southern Great Plains of North America. Abundance of birds was determined using fixed-radius point counts. Detrended correspondence analysis was used to compare plant community composition and canonical correspondence analysis was used to examine the relationships between plant species composition and vegetation structure with the bird community. Plant species composition differed distinctly between seeded grassland and native mixed prairie, but the differences were not reflected in habitat structure, bird community composition, or …

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Record Of Late Pleistocene Glaciation And Deglaciation In The Southern Cascade Range. I. Petrological Evidence From Lacustrine Sediment In Upper Klamath Lake, Southern Oregon, Richard L. Reynolds, Joseph G. Rosenbaum, Josh Rapp, Michael W. Kerwin, J. Platt Bradbury, David Adam, Steven Colman Jan 2004

Record Of Late Pleistocene Glaciation And Deglaciation In The Southern Cascade Range. I. Petrological Evidence From Lacustrine Sediment In Upper Klamath Lake, Southern Oregon, Richard L. Reynolds, Joseph G. Rosenbaum, Josh Rapp, Michael W. Kerwin, J. Platt Bradbury, David Adam, Steven Colman

United States Geological Survey: Staff Publications

Petrological and textural properties of lacustrine sediments from Upper Klamath Lake, Oregon, reflect changing input volumes of glacial flour and thus reveal a detailed glacial history for the southern Cascade Range between about 37 and 15 ka. Magnetic properties vary as a result of mixing different amounts of the highly magnetic, glacially generated detritus with less magnetic, more weathered detritus derived from unglaciated parts of the large catchment. Evidence that the magnetic properties record glacial flour input is based mainly on the strong correlation between bulk sediment particle size and parameters that measure the magnetite content and magnetic mineral freshness. …

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Paleolimnology And Paleoclimate Studies In Upper Klamath Lake, Oregon, Steven M. Colman, J. Platt Bradbury, Joseph G. Rosenbaum Jan 2004

Paleolimnology And Paleoclimate Studies In Upper Klamath Lake, Oregon, Steven M. Colman, J. Platt Bradbury, Joseph G. Rosenbaum

United States Geological Survey: Staff Publications

The subsiding Upper Klamath Lake Basin contains sediments that were continuously deposited in a shallow, freshwater lake for more than 40 000 years. Well dated by radiometric methods and containing volcanic ashes of known age, these sediments constitute a valuable paleoclimate record. Sediment constituents and properties that reflect past climatic conditions in the area include pollen, diatoms, sediment geochemistry, and sediment magnetic properties. Many of these proxy measurements are also useful for comparing natural conditions in the lake to conditions following human settlement. Because of its location, the paleoclimate record from Upper Klamath Lake is valuable for comparisons to offshore …

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Chronology Of Sediment Deposition In Upper Klamath Lake, Oregon, Steven M. Colman, J. Platt Bradbury, John P. Mcgeehin, Charles W. Holmes, David Edginton, Andrei M. Sarna-Wojcicki Jan 2004

Chronology Of Sediment Deposition In Upper Klamath Lake, Oregon, Steven M. Colman, J. Platt Bradbury, John P. Mcgeehin, Charles W. Holmes, David Edginton, Andrei M. Sarna-Wojcicki

United States Geological Survey: Staff Publications

A combination of tephrochronology and 14C, 210Pb, and 137Cs measurements provides a robust chronology for sedimentation in Upper Klamath Lake during the last 45 000 years. Mixing of surficial sediments and possible mobility of the radio-isotopes limit the usefulness of the 137Cs and 210Pb data, but 210Pb profiles provide reasonable average sediment accumulation rates for the last 100–150 years. Radiocarbon ages near the top of the core are somewhat erratic and are too old, probably as a result of detrital organic carbon, which may have become a more common component in recent times as …

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Mortality Of An Adult Cougar Due To A Forest Fire, Dorothy M. Fecske, Jonathan A. Jenks, Frederick D. Lindzey Jan 2004

Mortality Of An Adult Cougar Due To A Forest Fire, Dorothy M. Fecske, Jonathan A. Jenks, Frederick D. Lindzey

United States Geological Survey: Staff Publications

Mortality from natural causes has been documented throughout the range of the cougar (Puma concolor), including California (Beier and Barrett 1993), Canada (Ross et al. 1995), Florida (Taylor et al. 2002), Idaho (Hornocker 1970), Nevada (Ashman et al. 1983), New Mexico (Logan and Sweanor 2001), and Utah (Gashwiler and Robinette 1957, Lindzey et al. 1988). Intraspecific killing by adult males is the most common cause of death in unhunted populations; adult males have killed kittens, subadults, and adults of both sexes (Beier and Barrett 1993, Maehr 1997, Logan and Sweanor 2001, Taylor et al. 2002). Other mortality factors …

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Great Plains Ecosystems: Past, Present, And Future, Fred B. Samson, Fritz L. Knopf, Wayne Ostlie Jan 2004

Great Plains Ecosystems: Past, Present, And Future, Fred B. Samson, Fritz L. Knopf, Wayne Ostlie

United States Geological Survey: Staff Publications

Little questions exists that the main bodies of North American prairie (i.e., the tall-grass, mixed, and shortgrass) are among the most endangered resources on the continent. The purpose of this paper is to provide a past and present biological base- line by which to understand North American prairies and to provide a platform for future conservation. Events both immediate to the end of the Pleistocene and historic suggest that the present grassland conditions are different from those within which most of the grassland organisms evolved. Our analysis suggests that few grassland landscapes remain adequate in area and distribution to sustain …

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Genetic Structure Of Cougar Populations Across The Wyoming Basin: Metapopulation Or Megapopulation, Charles R. Anderson Jr., Federick G. Lindzey, David B. Mcdonald Jan 2004

Genetic Structure Of Cougar Populations Across The Wyoming Basin: Metapopulation Or Megapopulation, Charles R. Anderson Jr., Federick G. Lindzey, David B. Mcdonald

United States Geological Survey: Staff Publications

We examined the genetic structure of 5 Wyoming cougar (Puma concolor) populations surrounding the Wyoming Basin, as well as a population from southwestern Colorado. When using 9 microsatellite DNA loci, observed heterozygosity was similar among populations (HO = 0.49–0.59) and intermediate to that of other large carnivores. Estimates of genetic structure (FST = 0.028, RST = 0.029) and number of migrants per generation (Nm) suggested high gene flow. Nm was lowest between distant populations and highest among adjacent populations. Examination of these data, plus Mantel test results of genetic versus geographic distance (P ≤ 0.01), suggested both isolation …

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