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2007

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Articles 5521 - 5550 of 5729

Full-Text Articles in Physical Sciences and Mathematics

Species-Specific Visitation And Removal Of Baits For Delivery Of Pharmaceuticals To Feral Swine, Tyler A. Campbell, David B. Long Jan 2007

Species-Specific Visitation And Removal Of Baits For Delivery Of Pharmaceuticals To Feral Swine, Tyler A. Campbell, David B. Long

United States Department of Agriculture Wildlife Services: Staff Publications

Within the domestic swine industry there is growing trepidation about the role feral swine (Sus scrofa) play in the maintenance and transmission of important swine diseases. Innovative disease management tools for feral swine are needed. We used field trials conducted in southern Texas from February to March 2006 to compare species-specific visitation and removal rates of fish-flavored and vegetable-flavored baits with and without commercially available raccoon (Procyon lotor) repellent (trial 1) and removal rates of baits deployed in a systematic and cluster arrangement (trial 2). During trial 1, 1) cumulative bait removal rates after four nights …


Low-Energy Electron Capture By 6-Aza-2-Thiothymine: Investigations By Electron Attachment And Electron Transmission Spectroscopies, Stanislav A. Pshenichnyuk, Gordon A. Gallup, Paul Burrow Jan 2007

Low-Energy Electron Capture By 6-Aza-2-Thiothymine: Investigations By Electron Attachment And Electron Transmission Spectroscopies, Stanislav A. Pshenichnyuk, Gordon A. Gallup, Paul Burrow

Paul Burrow Publications

The interaction of low-energy (0-10 eV) electrons with 6-aza-2-thiothymine is investigated in the gas phase by studies of sharp structure in the total electron scattering cross section and by mass analysis of the stable or long-lived negative ions produced by electron attachment. The most efficient fragmentation process, occurring at 0.15 eV, involves the ejection of a closed-shell neutral molecule (CH3CN). Ab initio calculations support our proposal that this process leads to ring closure to form a stable four-member heterocyclic anion. A long-lived parent anion with an approximate lifetime of 75 microseconds is observed near zero electron energy, and …


Electronic Structure Of A Metal-Organic Copper Spin-½ Molecule: Bis(4-Cyano-2,2,6,6-Tetramethyl-3,5-Heptanedionato)Copper(Ii), David Wisbey, Danqin Feng, Marshall T. Bremer, Camelia N. Borca, Anthony N. Caruso, Carter M. Silvernail, John Belot, Elio Vescovo, Laurent Ranno, Peter A. Dowben Jan 2007

Electronic Structure Of A Metal-Organic Copper Spin-½ Molecule: Bis(4-Cyano-2,2,6,6-Tetramethyl-3,5-Heptanedionato)Copper(Ii), David Wisbey, Danqin Feng, Marshall T. Bremer, Camelia N. Borca, Anthony N. Caruso, Carter M. Silvernail, John Belot, Elio Vescovo, Laurent Ranno, Peter A. Dowben

Peter Dowben Publications

The metal-organic molecule bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II) (Cu- (CNdpm)2) (C24H36N2O4Cu, Cu(II)) is a copper spin-1/2 system with a magnetic moment of 1.05 ± 0.04 μB/molecule, slightly smaller than the 1.215±0.02 μB/molecule for the larger size copper spin-½ system C36H48N4O4Cu∙C4H8O (bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II) 4,4’-bipyridylethene- THF). There is generally good agreement between photoemission from vapor-deposited thin films of the C24H36N2O4Cu on Cu(111) and Co(111) and model calculations. Although this molecule is expected to …


Us Cms Tier-2 Computing, Kenneth A. Bloom Jan 2007

Us Cms Tier-2 Computing, Kenneth A. Bloom

Kenneth Bloom Publications

The CMS computing model relies heavily on the use of “Tier-2” computing centers. At LHC startup, the typical Tier-2 center in the United States will have 1 MSpecInt2K of CPU resources, 200 TB of disk for data storage, and a WAN connection of 10 Gbit/s. These centers will be the primary sites for the production of large-scale simulation samples and for the hosting of experiment data for user analysis – an interesting mix of experiment-controlled and user-controlled tasks. As a result, there are a wide range of services that must be deployed and commissioned at these centers, which are responsible …


Nebraska Cooperative Fish And Wildlife Research Unit: Report Of Activities October 2006 – October 2007, Craig R. Allen, Kevin L. Pope Jan 2007

Nebraska Cooperative Fish And Wildlife Research Unit: Report Of Activities October 2006 – October 2007, Craig R. Allen, Kevin L. Pope

School of Natural Resources: Faculty Publications

INTRODUCTION 1
PERSONNEL AND COOPERATORS 3
Unit Personnel 3
Coordinating Committee Members 5
Cooperators 6
MILESTONES 9
PROJECTS IN FISHERY SCIENCE 11
Impact of White Perch on Walleye at Branched Oak and Pawnee Reservoirs 13
Predators of White Perch at Branched Oak and Pawnee Reservoirs 14
Recruitment of Walleye and White Bass in Irrigation Reservoirs 15
PROJECTS IN WILDLIFE SCIENCE 17
Amphibian Monitoring Techniques (in Relation to Wetland Qualities and the Surrounding Landscape
– Rainwater Basin Region) 19
Assessing Local and Regional Variability in Productivity and Fidelity of Grassland Birds on National
Park Service Units in the Great Plains 20 …


Genetic Tagging Free-Ranging White-Tailed Deer Using Hair Snares, Jerrold L. Belant, Thomas W. Seamans, David Paetkau Jan 2007

Genetic Tagging Free-Ranging White-Tailed Deer Using Hair Snares, Jerrold L. Belant, Thomas W. Seamans, David Paetkau

United States Department of Agriculture Wildlife Services: Staff Publications

Use of noninvasive DNA-based tissue sampling (e.g., hair, scats) for individual identification in wildlife studies has increased markedly in recent years. Although field techniques for collecting hair samples have been developed for several species, we are unaware of their use with free-ranging ungulates. From December 2004 to August 2005 we evaluated the efficacy of barbed wire for snaring hair samples suitable for genetic analyses from white-tailed deer (Odocoileus virginianus) on trails and at baited sites. During initial trials on a semi-captive deer herd in northern Ohio, deer demonstrated avoidance of barbed wire positioned on game trails through four …


Current And Historical Use Of Alpha-Chloralose On Wild Turkeys, David Bergman, Brian F. Wakeling, Timothy B. Veenendaal, John D. Eisemann, Thomas W. Seamans Jan 2007

Current And Historical Use Of Alpha-Chloralose On Wild Turkeys, David Bergman, Brian F. Wakeling, Timothy B. Veenendaal, John D. Eisemann, Thomas W. Seamans

United States Department of Agriculture Wildlife Services: Staff Publications

Alpha-chloralose (AC) has been used as an anesthetic since 1897 to capture or sedate wildlife, including waterfowl, wood-pigeon (Columba palumbus), and black bear (Ursus americana). The first use of AC in the United States was for the capture of house sparrows (Passer domesticus), red-winged blackbirds (Agelaius phoeniceus), and wild turkeys (Meleagris gallopavo) in 1964. Prior to the 1990s, AC was not registered by the Food and Drug Administration (FDA) for use as an immobilizing agent in the United States for wild animals that might be used for human consumption. In …


Management Strategies For Addressing Wildlife Disease Transmission: The Case For Fertility Control, Gary Killian, Kathleen Fagerstone, Terry Kreeger, Lowell Miller, Jack Rhyan Jan 2007

Management Strategies For Addressing Wildlife Disease Transmission: The Case For Fertility Control, Gary Killian, Kathleen Fagerstone, Terry Kreeger, Lowell Miller, Jack Rhyan

United States Department of Agriculture Wildlife Services: Staff Publications

Transmissible diseases among wildlife species, and between wildlife and domestic livestock, are a matter of increasing concern. A combination of approaches should be considered for controlling disease transmission. If a vaccine is available or can economically be developed for the disease, it should be used as the primary component of the disease management strategy. For example, development of an oral rabies vaccine has led to programs where baits are dispersed on a large scale in a barrier zone to prevent the spread of rabies. However, there are no vaccines available for many diseases and incentives are frequently not present for …


Use Of Alpha-Chloralose By Usda Wildlife Services To Immobilize Birds, Jeanette R. O'Hare, John D. Eisemann, Kathleen A. Fagerstone, Lawanna L. Koch, Thomas W. Seamans Jan 2007

Use Of Alpha-Chloralose By Usda Wildlife Services To Immobilize Birds, Jeanette R. O'Hare, John D. Eisemann, Kathleen A. Fagerstone, Lawanna L. Koch, Thomas W. Seamans

United States Department of Agriculture Wildlife Services: Staff Publications

In 1992, the U. S. Food and Drug Administration (FDA) opened an Investigational New Animal Drug (INAD) file for the avian immobilizing agent, alpha-chloralose (AC) for the United States Department of Agriculture, Animal and Plant Health Inspection Service (APHIS). Currently, this INAD authorizes trained Wildlife Services (WS) personnel to use AC to immobilize and live-capture nuisance waterfowl (Anatidae spp.), American coots (Fulica americana), pigeons (Columba livia), common ravens (Corvus corax) and sandhill cranes (Grus canadensis). The use of AC has proven to be a valuable tool for WS and the number …


S-Extremal Additive F4 Codes, Evangeline P. Bautista, Philippe Gaborit, Jon-Lark Kim, Judy L. Walker Jan 2007

S-Extremal Additive F4 Codes, Evangeline P. Bautista, Philippe Gaborit, Jon-Lark Kim, Judy L. Walker

Department of Mathematics: Faculty Publications

Binary self-dual codes and additive self-dual codes over F4 have in common interesting properties, for example, Type I, Type II, shadows, etc. Recently Bachoc and Gaborit introduced the notion of s-extremality for binary self-dual codes, generalizing Elkies' study on the highest possible minimum weight of the shadows of binary self-dual codes. In this paper, we introduce a concept of s-extremality for additive self-dual codes over F4, give a bound on the length of these codes with even distance d, classify them up to minimum distance d = 4, give possible lengths and (shadow) weight …


An Improved Qc Process For Temperature In The Daily Cooperative Weather Observations, Kenneth Hubbard, Nathaniel B. Guttman, Jinsheng You, Zhirong Chen Jan 2007

An Improved Qc Process For Temperature In The Daily Cooperative Weather Observations, Kenneth Hubbard, Nathaniel B. Guttman, Jinsheng You, Zhirong Chen

Department of Earth and Atmospheric Sciences: Faculty Publications

TempVal is a spatial component of data quality assurance algorithms applied by the National Climatic Data Center (NCDC), and it has been used operationally for about 4 yr. A spatial regression test (SRT) approach was developed at the regional climate centers for climate data quality assurance and was found to be superior to currently used quality control (QC) procedures for the daily maximum and minimum air temperature. The performance of the spatial quality assessment procedures has been evaluated by assessing the rate with which seeded errors are identified. A complete dataset with seeded errors for the year 2003 for the …


High-Resolution Evidence For Dynamic Transitional Geomagnetic Field Behaviour From A Miocene Reversal, Mcmurdo Sound, Ross Sea, Antarctica, Andrew P. Roberts, Anisch Bakrania, Fabio Florindo, Christopher J. Rowan, Christopher R. Fielding, Ross D. Powell Jan 2007

High-Resolution Evidence For Dynamic Transitional Geomagnetic Field Behaviour From A Miocene Reversal, Mcmurdo Sound, Ross Sea, Antarctica, Andrew P. Roberts, Anisch Bakrania, Fabio Florindo, Christopher J. Rowan, Christopher R. Fielding, Ross D. Powell

Department of Earth and Atmospheric Sciences: Faculty Publications

We report a high-resolution record of a Miocene polarity transition (probably the Chron C6r-C6n transition) from glacimarine sediments in McMurdo Sound, Ross Sea, Antarctica, which is the first transition record reported from high southern latitudes. The transition is recorded in two parallel cores through a 10.7 m stratigraphic thickness. The sediments are interpreted as having been deposited in a marine environment under the influence of floating ice or seaward of a glacier terminus from which a large sediment load was delivered to the drill site. The core was recovered using rotary drilling, which precludes azimuthal orientation of the core and …


A Method For Estimating Fractal Dimension Of Tree Crowns From Digital Images, Dongsheng Zhang, Ashok Samal, James R. Brandle Jan 2007

A Method For Estimating Fractal Dimension Of Tree Crowns From Digital Images, Dongsheng Zhang, Ashok Samal, James R. Brandle

School of Computing: Faculty Publications

A new method for estimating fractal dimension of tree crowns from digital images is presented. Three species of trees, Japanese yew (Taxus cuspidata Sieb & Zucc), Hicks yew (Taxus × media), and eastern white pine (Pinus strobus L.), were studied. Fractal dimensions of Japanese yew and Hicks yew range from 2.26 to 2.70. Fractal dimension of eastern white pine range from 2.14 to 2.43. The difference in fractal dimension between Japanese yew and eastern white pine was statistically significant at 0.05 significance level as was the difference in fractal dimension between Hicks yew and eastern white …


Keyrev: An Efficient Key Revocation Scheme For Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy, Xukai Zou Jan 2007

Keyrev: An Efficient Key Revocation Scheme For Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy, Xukai Zou

School of Computing: Conference and Workshop Papers

Key management is a core mechanism to ensure the security of applications and network services in wireless sensor networks. It includes two aspects: key distribution and key revocation. Key distribution has been extensively studied in the context of sensor networks. However, key revocation has received relatively little attention. Existing key revocation schemes can be divided into two categories: centralized key revocation scheme and distributed key revocation scheme. In this paper, we first summarize the current key revocation schemes for sensor networks. Then, we propose an efficient centralized key revocation scheme, KeyRev, for wireless sensor networks. Unlike most proposed key revocation …


Group Rekeying Schemes For Secure Group Communication In Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy Jan 2007

Group Rekeying Schemes For Secure Group Communication In Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Wireless sensor networks are promising solutions for many applications. However, wireless sensor nodes suffer from many constraints such as low computation capability, small memory, limited energy resources, and so on. Grouping is an important technique to localize computation and reduce communication overhead in wireless sensor networks. In this paper, we use grouping to refer to the process of combining a set of sensor nodes with similar properties. We propose two centralized group rekeying (CGK) schemes for secure group communication in sensor networks. The lifetime of a group is divided into three phases, i.e., group formation, group maintenance, and group dissolution. …


Layered Clustering Communication Protocol For Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy Jan 2007

Layered Clustering Communication Protocol For Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

In this paper, we propose a Layered Clustering Hierarchy (LCH) communication protocol for Wireless Sensor Networks (WSNs). The design of LCH has two goals: scalability and energy-efficiency. In LCH, the sensor nodes are organized as a layered clustering structure. Each layer runs a distributed clustering protocol. By randomizing the rotation of cluster heads in each layer, the energy load is distributed evenly across sensors in the network. Our simulations show that LCH is effective in densely deployed sensor networks. On average, 70% of live sensor nodes are involved directly in the clustering communication hierarchy. Moreover, the simulations also show that …


Bandit-Based Algorithms For Budgeted Learning, Kun Deng, Chris Bourke, Stephen Scott, Julie Sunderman, Yaling Zheng Jan 2007

Bandit-Based Algorithms For Budgeted Learning, Kun Deng, Chris Bourke, Stephen Scott, Julie Sunderman, Yaling Zheng

School of Computing: Conference and Workshop Papers

We explore the problem of budgeted machine learning, in which the learning algorithm has free access to the training examples’ labels but has to pay for each attribute that is specified. This learning model is appropriate in many areas, including medical applications. We present new algorithms for choosing which attributes to purchase of which examples in the budgeted learning model based on algorithms for the multi-armed bandit problem. All of our approaches outperformed the current state of the art. Furthermore, we present a new means for selecting an example to purchase after the attribute is selected, instead of selecting an …


An Interactive Constraint-Based Approach To Sudoku, Christopher G. Reeson, Kai-Chen Huang, Ken Bayer, Berthe Y. Choueiry Jan 2007

An Interactive Constraint-Based Approach To Sudoku, Christopher G. Reeson, Kai-Chen Huang, Ken Bayer, Berthe Y. Choueiry

School of Computing: Conference and Workshop Papers

We present SOLVER, a Java applet that uses Constraint Processing (CP) techniques to assist human users in solving Sudoku puzzles. We also showcase CONSTRUCTOR, another applet that allows users to enter and store puzzles, which they can then load in SOLVER. These applets are available from sudoku.unl.edu/Solver and sudoku. unl.edu/Constructor. Our goals are as follows:

• To the public: Illustrate the power of CP techniques in the context of a popular easily approachable puzzle.

• For the research: Investigate how to use CP to interactively support and guide human players.

• For education: Use the Sudoku puzzle as a means …


Efficient Rtl Coverage Metric For Functional Test Selection, Jian Kang, Sharad C. Seth, Vijay Gangaram Jan 2007

Efficient Rtl Coverage Metric For Functional Test Selection, Jian Kang, Sharad C. Seth, Vijay Gangaram

School of Computing: Conference and Workshop Papers

For performance-critical microprocessors, efficient test-selection methods are needed for reusing a subset of functional validation tests to detect manufacturing defects. Our new input/output transition fault-coverage metric (TRIO) at the register-transfer level is shown to perform much better than current metric in test selection at only an incrementally higher computational cost. TRIO may also be used for testability analysis early in the design cycle.


Symbolic Path Sensitization Analysis And Applications, Jian Kang, Sharad C. Seth, Shashank K. Mehta Jan 2007

Symbolic Path Sensitization Analysis And Applications, Jian Kang, Sharad C. Seth, Shashank K. Mehta

School of Computing: Conference and Workshop Papers

A new symbolic approach models the sensitization paths to selected primary output(s) as Boolean equations, with satisfying solutions representing the set of all sources of single and multiple sensitizations in the circuit. The paper discusses two applications of this idea: model-free fault diagnosis and input sensitization analysis.


A Note On The Karp-Lipton Collapse For The Exponential Hierarchy, Chris Bourke Jan 2007

A Note On The Karp-Lipton Collapse For The Exponential Hierarchy, Chris Bourke

School of Computing: Technical Reports

We extend previous collapsing results involving the exponential hierarchy by using recent hardness-randomness trade-off results. Specifically, we show that if the second level of the exponential hierarchy has polynomial-sized circuits, then it collapses all the way down to MA.


Network Architectures For Live Peer-To-Peer Media Streaming, Jagannath Ghoshal, Lisong Xu, Byrav Ramamurthy, Miao Wang Jan 2007

Network Architectures For Live Peer-To-Peer Media Streaming, Jagannath Ghoshal, Lisong Xu, Byrav Ramamurthy, Miao Wang

School of Computing: Technical Reports

Peer-to-Peer (P2P) media streaming networks, motivated by the huge success of P2P file downloading networks, have recently attracted a lot of research interest. However, it is challenging to design P2P media streaming networks because of the stringent time constraints on the delivered media streams, which require more efficient and resilient overlay architectures. In this paper, we focus on live P2P media streaming networks, a promising application flourishing in the Internet and which requires the distribution of live (not stored) multimedia content to subscribers. We review the architectures for live P2P media streaming networks, and consider both overlay topologies and their …


Experimenting With Software Testbeds For Evaluating New Technologies, Mikael Lindvall, Ioana Rus, Paolo Donzelli, Atif Memon, Marvin Zelkowitz, Aysu Betin-Can, Tevfik Bultan, Chris Ackermann, Bettina Anders, Sima Asgari, Victor Basili, Lorin Hochstein, Jörg Fellmann, Forrest Shull, Roseanne Tvedt, Daniel Pech, Daniel Hirschbach Jan 2007

Experimenting With Software Testbeds For Evaluating New Technologies, Mikael Lindvall, Ioana Rus, Paolo Donzelli, Atif Memon, Marvin Zelkowitz, Aysu Betin-Can, Tevfik Bultan, Chris Ackermann, Bettina Anders, Sima Asgari, Victor Basili, Lorin Hochstein, Jörg Fellmann, Forrest Shull, Roseanne Tvedt, Daniel Pech, Daniel Hirschbach

School of Computing: Faculty Publications

The evolution of a new technology depends upon a good theoretical basis for developing the technology, as well as upon its experimental validation. In order to provide for this experimentation, we have investigated the creation of a software testbed and the feasibility of using the same testbed for experimenting with a broad set of technologies. The testbed is a set of programs, data, and supporting documentation that allows researchers to test their new technology on a standard software platform. An important component of this testbed is the Unified Model of Dependability (UMD), which was used to elicit dependability requirements for …


A-Mac: Adaptive Medium Access Control For Next Generation Wireless Terminals, Mehmet C. Vuran, Ian F. Akyildiz Jan 2007

A-Mac: Adaptive Medium Access Control For Next Generation Wireless Terminals, Mehmet C. Vuran, Ian F. Akyildiz

School of Computing: Faculty Publications

Next Generation (NG) wireless networks are envisioned to provide high bandwidth to mobile users via bandwidth aggregation over heterogeneous wireless architectures. NG wireless networks, however, impose challenges due to their architectural heterogeneity in terms of different access schemes, resource allocation techniques as well as diverse quality of service requirements. These heterogeneities must be captured and handled dynamically as mobile terminals roam between different wireless architectures. However, to address these challenges, the existing proposals require either a significant modification in the network structure and in base stations or a completely new architecture, which lead to integration problems in terms of implementation …


A Two-Phase Approach For Dynamic Lightpath Scheduling In Wdm Optical Networks, Lu Shen, Xi Yang, Ajay Todimala, Byrav Ramamurthy Jan 2007

A Two-Phase Approach For Dynamic Lightpath Scheduling In Wdm Optical Networks, Lu Shen, Xi Yang, Ajay Todimala, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Lightpath scheduling is an important capability in next-generation wavelength-division multiplexing (WDM) optical networks to reserve resources in advance for a specified time period while provisioning end-to-end lightpaths. In a dynamic environment, the end user requests for dynamic scheduled lightpath demands (D-SLDs) need to be serviced without the knowledge of future requests. Even though the starting time of the request may be hours or days from the current time, the end-user however expects a quick response as to whether the request could be satisfied. We propose a two-phase approach to dynamically schedule and provision D-SLDs. In the first phase, termed the …


A Novel Over-Sea-Ice Seismic Reflection Survey In Mcmurdo Sound, Antarctica, S. J. Betterly, M. A. Speece, R. H. Levy, David M. Harwood, S. A. Henrys Jan 2007

A Novel Over-Sea-Ice Seismic Reflection Survey In Mcmurdo Sound, Antarctica, S. J. Betterly, M. A. Speece, R. H. Levy, David M. Harwood, S. A. Henrys

Department of Earth and Atmospheric Sciences: Faculty Publications

During the austral spring of 2005, approximately 28 km of over-sea-ice seismic reflection data were recorded over McMurdo Sound, Antarctica, in support of the ANtarctic geological DRILLing Program (ANDRILL). The 2005 ANDRILL Southern McMurdo Sound Project (SMS) seismic survey incorporated techniques that improved the quality of over-sea-ice seismic data. Previous over-sea-ice seismic experiments have had limited success because of poor source coupling caused by thin sea ice and source bubble-pulse effects caused by explosive seismic sources placed in the water column. To mitigate these problems, a Generator-Injector (GI) air gun was used as the seismic source. The GI air gun …


Preservation And Erosion Of Theropod Tracks In Eolian Deposits: Examples From The Middle Jurassic Entrada Sandstone, Utah, U.S.A., Jesper Milán, David B. Loope Jan 2007

Preservation And Erosion Of Theropod Tracks In Eolian Deposits: Examples From The Middle Jurassic Entrada Sandstone, Utah, U.S.A., Jesper Milán, David B. Loope

Department of Earth and Atmospheric Sciences: Faculty Publications

The Middle Jurassic Entrada Sandstone, exposed near the town of Escalante, southern Utah, consists of large-scale cross-bedded eolian deposits that are interbedded with horizontally laminated sand sheets and thin sets of eolian cross-strata, representing periods with a moister climate. The flat-bedded units contain numerous tracks and trackways from small to large-sized theropod dinosaurs. These tracks are today exposed in several distinct erosional states, allowing detailed studies of track and undertrack formation in eolian deposits. Tracks that originally were emplaced on sloping surfaces show, in their present-day erosional state, a morphology distinct from those originally emplaced on horizontal surfaces. Further, the …


Dinosaur Tectonics: A Structural Analysis Of Theropod Undertracks With A Reconstruction Of Theropod Walking Dynamics, Ole Graversen, Jesper Milán, David B. Loope Jan 2007

Dinosaur Tectonics: A Structural Analysis Of Theropod Undertracks With A Reconstruction Of Theropod Walking Dynamics, Ole Graversen, Jesper Milán, David B. Loope

Department of Earth and Atmospheric Sciences: Faculty Publications

A dinosaur trackway in the Middle Jurassic eolian Entrada Sandstone of southern Utah, U.S.A., exposes three undertracks that we have modeled as isolated tectonic regimes showing the development of fold-thrust ramp systems induced by the dinosaur’s feet. The faulted and folded sequence is comparable to crustal-scale tectonics associated with plate tectonics and foreland fold-thrust belts. A structural analysis of the dinosaur tracks shows the timing and direction of the forces exercised on the substrate by the animal’s foot during the stride. Based on the structural analysis, we establish a scenario for foot movements and weight distribution in the feet. During …


Quantitative Analysis Of The Calcareous Nannofossil Assemblages From Ciros-1, Victoria Land Basin, Antarctica, David K. Watkins Jan 2007

Quantitative Analysis Of The Calcareous Nannofossil Assemblages From Ciros-1, Victoria Land Basin, Antarctica, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

The lower portion of the CIROS-1 core (McMurdo Sound, Antarctica) has been cited as evidence for Late Eocene continental glaciation on Antarctica. A reassessment of this age determination is warranted in the face of mounting evidence from multiple proxies that continental glaciation was initiated by rapid ice-growth during the earliest Oligocene. Examination of calcareous nannofossil assemblages from this section confirmed very low fossil abundance, low species richness, and the presence of reworked taxa. A minimum of 37% of the total species richness in the section comprises reworked forms, including Late Cretaceous and latest Paleocene to Middle Eocene species. Quantitative analysis …


Evaluation Of The Streambed Leakage Concept In Analytical Models Using Data From Three Pumping Tests, Sefan J. Kollet, Vitaly A. Zlotnik Jan 2007

Evaluation Of The Streambed Leakage Concept In Analytical Models Using Data From Three Pumping Tests, Sefan J. Kollet, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

Two-dimensional analytical models of pumping induced drawdown and stream depletion account for the streambed properties and stream geometry. Using data from three pumping tests performed under various hydrologic conditions, the following hypotheses were tested: (1) a partially penetrating stream at a certain distance from the pumping well can be represented by the streambed leakage term in the analytical models; (2) in the streambed leakage term, the streambed conductance coefficient λ=(WK′)/m′ accounts for the average stream width W, the streambed thickness m′, and hydraulic conductivity K′. The first hypothesis was tested by comparing results from tests under flow and no-flow stream …