Physical Sciences and Mathematics Commons^™

Subspecific Relationships And Genetic Structure In The Spotted Owl, Susan M. Haig, Thomas D. Mullins, Eric D. Forsman

United States Geological Survey: Staff Publications

Hierarchical genetic structure was examined in the three geographically-defined subspecies of spotted owl (Strix occidentalis) to define relationships among subspecies and quantify variation within and among regional and local populations. Sequences (522 bp) from domains I and II of the mitochondrial control region were analyzed for 213 individuals from 30 local breeding areas. Results confirmed significant differences between northern spotted owls and the other traditional geographically defined subspecies but did not provide support for subspecific level differences between California and Mexican spotted owls. Divergence times among subspecies estimated with a 936 bp portion of the cytochrome b gene …

An Association Of Benthic Foraminifera And Gypsum In Holocene Sediments Of Estuarine Chesapeake Bay, Usa, John Cann, Thomas Cronin

United States Geological Survey: Staff Publications

Two cores of Holocene sediments recovered from the Cape Charles Channel of Chesapeake Bay yielded radiocarbon ages of about 6.8 to 5.8 ka for the lower intervals. Fossil foraminifera preserved in these lower sediments are dominated by species of Elphidium, which make up about 90% of the assemblage throughout, and probably signify deposition in hypersaline waters. Buccella frigida and Ammonia beccarii are the only other species commonly present. Hypersalinity of bottom waters seems to have been maintained by water-density stratification in a basin-like section of the channel. In core PTXT -4-P-I transition to modem Chesapeake conditions, in which numbers …

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 …

Streaks, Multiplets, And Holes: High-Resolution Spatio-Temporal Behavior Of Parkfield Seismicity, F. Waldhauser, W. L. Ellsworth, D. P. Schaff, A. Cole

United States Geological Survey: Staff Publications

Double-difference locations of ~8000 earthquakes from 1969–2002 on the Parkfield section of the San Andreas Fault reveal detailed fault structures and seismicity that is, although complex, highly organized in both space and time. Distinctive features of the seismicity include: 1) multiple recurrence of earthquakes of the same size at precisely the same location on the fault (multiplets), implying frictional or geometric controls on their location and size; 2) sub-horizontal alignments of hypocenters along the fault plane (streaks), suggestive of rheological transitions within the fault zone and/or stress concentrations between locked and creeping areas; 3) regions devoid of microearthquakes with typical …

Introduction To Special Section: Preparing For The San Andreas Fault Observatory At Depth, Stephen Hickman, Mark D. Zoback, William Ellsworth

United States Geological Survey: Staff Publications

The San Andreas Fault Observatory at Depth (SAFOD) is a comprehensive project to drill into the hypocentral zone of repeating M ~ 2 earthquakes on the San Andreas Fault at a depth of about 3 km. The goals of SAFOD are to establish a multi-stage geophysical observatory in close proximity to these repeating earthquakes, to carry out a comprehensive suite of downhole measurements in order to study the physical and chemical conditions under which earthquakes occur and to exhume rock and fluid samples for extensive laboratory studies. In the vicinity of SAFOD, the San Andreas is moving through a combination …

Stress Orientations And Magnitudes In The Safod Pilot Hole, Stephen Hickman, Mark D. Zoback

United States Geological Survey: Staff Publications

Borehole breakouts and drilling-induced tensile fractures in the 2.2-km-deep SAFOD pilot hole at Parkfield, CA, indicate significant local variations in the direction of the maximum horizontal compressive stress, SHmax, but show a generalized increase in the angle between SHmax and the San Andreas Fault with depth. This angle ranges from a minimum of 25 ± 10 ° at 1000–1150 m to a maximum of 69 ± 14 ° at 2050–2200 m. The simultaneous occurrence of tensile fractures and borehole breakouts indicates a transitional strike-slip to reverse faulting stress regime with high horizontal differential stress, although there is considerable uncertainty in …

Stress-Induced, Time-Dependent Fracture Closure At Hydrothermal Conditions, N. M. Beeler, S. H. Hickman

United States Geological Survey: Staff Publications

Time-dependent closure of fractures in quartz was measured in situ at 22–530 °C temperature and 0.1–150 MPa water pressure. Unlike previous crack healing and rock permeability studies, in this study, fracture aperture is monitored directly and continuously using a windowed pressure vessel, a long-working-distance microscope, and reflectedlight interferometry. Thus the fracture volume and geometry can be measured as a function of time, temperature, and water pressure. Relatively uniform closure occurs rapidly at temperatures and pressures where quartz becomes significantly soluble in water. During closure the aperture is reduced by as much as 80% in a few hours. We infer that …

In Situ Stress, Fracture, And Fluid Flow Analysis In Well 38c-9: An Enhanced Geothermal System In The Coso Geothermal Field, Judith M. Sheridan, Stephen H. Hickman

United States Geological Survey: Staff Publications

Geoscientists from the Coso Operating Company, EGI-Utah, GeoMechanics International, and the United States Geological Survey are cooperating in a multi-year study to develop an Enhanced Geothermal System (EGS) in the Coso Geothermal Field. Key to the creation of an EGS is an understanding of the relationship among natural fracture distribution, fluid flow, and the ambient tectonic stresses that exist within the resource in order to design a hydraulic and thermal stimulation of an east-flank injection well, the first step in the creation of a heat exchanger at depth. Well datasets from the east flank of the Coso Geothermal Field are …

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 …

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 …

Testing Density-Dependent Groundwater Models: Two-Dimensional Steady State Unstable Convection In Infinite, Finite And Inclined Porous Layers, Douglas Weatherill, Craig T. Simmons, Clifford I. Voss, Neville I. Robinson

United States Geological Survey: Staff Publications

This study proposes the use of several problems of unstable steady state convection with variable fluid density in a porous layer of infinite horizontal extent as two-dimensional (2-D) test cases for density-dependent groundwater flow and solute transport simulators. Unlike existing density-dependent model benchmarks, these problems have well-defined stability criteria that are determined analytically. These analytical stability indicators can be compared with numerical model results to test the ability of a code to accurately simulate buoyancy driven flow and diffusion. The basic analytical solution is for a horizontally infinite fluid-filled porous layer in which fluid density decreases with depth. The proposed …

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- …

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 …

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.

Electron Irradiation Effects On Ferroelectric Copolymer Langmuir-Blodgett Films, Christina M. Othon, Stephen Ducharme

Stephen Ducharme Publications

The effect of irradiation on the ferroelectric properties of Langmuir-Blodgett films of the copolymer poly(vinylidene fluoride-trifluorethelene) is investigating using 1.26 MeV electrons with dosages from 16 to 110 Mrad. Irradiation causes a systematic decrease in the phase transition temperature, coercive field and polarization of these thin films.

Ferroelectricity At Molecular Level, L. M. Blinov, A. V. Bune, Peter A. Dowben, Stephen Ducharme, Vladimir M. Fridkin, S. P. Palto, K. A. Verkhovskaya, G. V. Vizdrik, S. G. Yudin

Stephen Ducharme Publications

he synthesis of ultrathin ferroelectric nanostructures by the Langmuir-Blodgett method and their properties are reviewed. It is shown that ferroelectricity exists in one monolayer of the ferroelectric P(VDF-TrFE) copolymer, i.e., at the molecular level. The specific characteristics of switching of ultrathin ferroelectric films are established.

Do Meteorologists Suppress Thunderstorms? Radar-Derived Statistics And The Behavior Of Moist Convection, Matthew D. Parker, Jason C. Knievel

Department of Earth and Atmospheric Sciences: Faculty Publications

Most meteorologists are acquainted with the notion of a weather hole—that is, a place that receives less exciting weather than does its surroundings. Exciting weather takes many forms, but when people use the term weather hole, they tend to mean a place that thunderstorms often barely miss, or near which approaching storms often dissipate. For this paper, that is the meaning we adopt.

In our experience, many meteorologists and lay weather enthusiasts genuinely believe that they live in weather holes, and this belief, almost without fail, seems to stem from countless hours spent gazing at displays of radar reflectivity. We …

Livestock Depredations By Black Vultures And Golden Eagles, Michael L. Avery, J. L. Cummings

United States Department of Agriculture Wildlife Services: Staff Publications

Black Vulture: The available evidence suggests that black vultures act as typical predators by seeking and disabling vulnerable animals prior to overwhelming and killing them (Gluesing et al., 1980). These birds take the path of least resistance and eat carrion when it is available. Black vultures are opportunists, however, and when the chance arises, they will attack and eat defenseless live animals. Defenseless does not necessarily mean sick or injured. Healthy newborn livestock are defenseless, especially if the mother is exhausted or otherwise not able to care for and protect the offspring. In assessing the role of black vultures as …

Double-Crested Comorants In Alabama, Scott C. Barras

United States Department of Agriculture Wildlife Services: Staff Publications

No abstract provided.

Evaluating Population Management Scenarios: Crunching The Numbers Before Going To The Field, Bradley F. Blackwell, Brian E. Washburn, Michael J. Begier

United States Department of Agriculture Wildlife Services: Staff Publications

Effolts to mitigate wildlife-human conflicts tpically involve management of unacceptably abundant populations. Increasingly, however, reduction of dense or increasing populations of certain wild species evokes both support and contention kom the public. Management decisions involving population reduction, particularly those directed at highly visible species, should therefore be based on quantitative evaluation of potential outcomes prior to implementation. The purpose of th~sp aper is to revisit a call for use of population modeling in management decisions by reviewing basic aspects of population analysis and the use of publicly available long-term data sets in environmental assessments and impact statements. Our objectives are …

Evaluation Of A Deer-Activated Bioacoustic Frightening Device For Reducing Deer Damage In Cornfields, Jason M. Gildorf, Scott E. Hygnstrom, Kurt C. Vercauteren, Greg M. Clements, Erin E. Blankenship, Richard M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

Deer (Odocoileus spp.) can cause substantial damage to agricultural crops, resulting in economic losses for producers. We developed a deer-activated bio-acoustic frightening device to reduce white-tailed deer (O. virginianus) damage in agricultural fields. The device consisted of an infrared detection system that activated an audio component which broadcast recorded distress and alarm calls of deer. We tested the device against unprotected controls in cornfields during the silking–tasseling stage of growth in July 2001. The device was not effective in reducing damage: track-count indices (F1,4=0.02, P=0.892), corn yield (F1,9=1.27, P=0.289), and estimated damage levels (F1,10=0.87, P=0.374) did not differ between experimental …

Predacides For Canid Predation Management, K. A. Fagerstone, J. J. Johnston, P. J. Savarie

United States Department of Agriculture Wildlife Services: Staff Publications

Throughout the livestock industry in the western United States, control of canid predators was considered to be of considerable importance to the livestock industry, especially to sheep producers, who sufkred high losses from coyotes and wolves. In the 19th century, the demand for predator control was communicated to Congress and the western state assemblies, with the result that predator control was provided in western states by the Fedcral Bureau of Biological Survey in cooperation with state agencies, and by trappers hired by stockmen. Steel traps and poisons were the principal methods used for predator control during the early years of …

A Review Of The Colonization Dynamics Of The Northern Curly-Tailed Lizard (Leiocephalus Carinatus Armouri) In Florida, Henry T. Smith, Richard M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

No abstract provided.

Special Section On The Algorithmics Of Software Model Checking — Introductory Paper, Matthew Dwyer, Stefan Leue

School of Computing: Faculty Publications

The term “software model checking” has recently been coined to refer to a flourishing area of research in software verification – the formal, automated analysis of program source code. Software model checking is considered an important application of classical model checking, where the model of a software system is analyzed in an automated fashion for compliance with a property specification. While classical model checking assumes the existence of an abstract model of the software system to be analyzed, in software model checking the emphasis is on directly analyzing program code given in a standard programming language, such as Java or …

Survivable Virtual Topology Routing Under Shared Risk Link Groups In Wdm Networks, Ajay Todimala, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Network survivability is one of the most important issues in the design of optical WDM networks. In this work we study the problem of survivable routing of a virtual topology on a physical topology with Shared Risk Link Groups (SRLG). The survivable virtual topology routing problem against single-link failures in the physical topology is proved to be NP-complete in [1]. We prove that survivable virtual topology routing problem against SRLG/node failures is also NP-complete. We present an improved integer linear programming (ILP) formulation (in comparison to [1]) for computing the survivable routing under SRLG/node failures. Using an ILP solver, we …

Imsh: An Iterative Heuristic For Srlg Diverse Routing In Wdm Mesh Networks, Ajay Todimala, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Survivable routing of a connection involves computation of a pair of diverse routes such that at most one mute fails when failures occur in the network topology. A subset of links in the network that share the risk of failure at the same time are said to belong to a Shared Risk Link Group (SRLG) [3]. A network with shared risk link groups defined over its links is an SRLG network. A failure of an SRLG is equivalent to the failure of all the links in the SRLG. For a connection to he survivable in an SRLG network its working …

An Analysis Of Mcmc Sampling Methods For Estimating Weighted Sums In Winnow, Qingping Tao, Stephen Scott

School of Computing: Technical Reports

Chawla et al. introduced a way to use the Markov chain Monte Carlo method to estimate weighted sums in multiplicative weight update algorithms when the number of inputs is exponential. But their algorithm still required extensive simulation of the Markov chain in order to get accurate estimates of the weighted sums. We propose an optimized version of Chawla et al.’s algorithm, which produces exactly the same classifications while often using fewer Markov chain simulations. We also apply three other sampling techniques and empirically compare them with Chawla et al.’sMetropolis sampler to determine how effective each is in drawing good samples …

Rerouting Schemes For Dynamic Traffic Grooming In Optical Wdm Mesh Networks, Wang Yao, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Traffic grooming in optical WDM mesh networks is a two-layer routing problem to effectively pack low-rate connections onto high-rate lightpaths, which, in turn, are established on wavelength links. In this work, we employ the rerouting approach to improve the network throughput under the dynamic traffic model. We propose two rerouting schemes, rerouting at lightpath level (RRAL) and rerouting at connection level (RRAC). A qualitative comparison is made between RRAL and RRAC. We also propose the critical-wavelength-avoiding one-lightpath-limited (CWA-1L) and critical-lightpath-avoiding one-connection-limited (CLA-1C) rerouting heuristics, which are based on the two rerouting schemes respectively. Simulation results show that rerouting reduces the …

Maximizing Resource Sharing In Wdm Mesh Networks With Path-Based Protection And Sparse Oeo Regeneration, Xi Yang, Byrav Ramamurthy, Lu Shen

School of Computing: Conference and Workshop Papers

We propose a resource-sharing scheme that supports three kinds of sharing scenarios in a WDM mesh network with path-based protection and sparse OEO regeneration. Several approaches are used to maximize the sharing of wavelength-links and OEO regenerators.

Survivable Traffic Grooming With Path Protection At The Connection Level In Wdm Mesh Networks, Wang Yao, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Survivable traffic grooming (STG) is a promising approach to provide reliable and resource-efficient multigranularity connection services in wavelength division multiplexing (WDM) optical networks. In this paper, we study the STG problem in WDM mesh optical networks employing path protection at the connection level. Both dedicated protection and shared protection schemes are considered. Given the network resources, the objective of the STG problem is to maximize network throughput. To enable survivability under various kinds of single failures such as fiber cut and duct cut, we consider the general shared risk link group (SRLG) diverse routing constraints. We first resort to the …