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2004

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Articles 2401 - 2430 of 4447

Full-Text Articles in Physical Sciences and Mathematics

Effects Of Aerial Lines On Red-Winged Blackbird Nesting, William H. Clark, George M. Linz, William J. Bleier Feb 2004

Effects Of Aerial Lines On Red-Winged Blackbird Nesting, William H. Clark, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications


The Red-winged blackbird (RWBL) is one of the most abundant birds in all of North America (Dolbeer 1980, Beletsky 1996). Red-winged blackbird damage to crops continues to be a dilemma in localized areas of the United States (Dolbeer 1980). In addition to economic losses, bird damage may intensify conflicts between agricultural interests and the enforcement of laws defending wildlife and their habitats (Stone et al. 1984). When chemicals are shown to be environmentally harmful or when public unease grows over the mass killing of wildlife, new methods of repelling blackbirds need to be evaluated. A more humane and less hazardous …


Dedicated Polarimeter Design For Hard X-Ray And Soft Gamma-Ray Astronomy, Mark L. Mcconnell, J Ledoux, John R. Macri, James M. Ryan Feb 2004

Dedicated Polarimeter Design For Hard X-Ray And Soft Gamma-Ray Astronomy, Mark L. Mcconnell, J Ledoux, John R. Macri, James M. Ryan

Space Science Center

We have developed a modular design for a hard X-ray and soft gamma-ray polrimeter that we call GRAPE (Gamma RAy Polarimeter Experiment). Optimized for the energy range of 50-300 keV, the GRAPE design is a Compton polarimeter based on the use of an array of plastic scintillator scattering elements in conjunction with a centrally positioned high-Z calorimeter detector. Here we shall review the results from a laboratory model of the baseline GRAPE design. The baseline design uses a 5-inch diameter position sensitive PMT (PSPMT) for readout of the plastic scintillator array and a small array of CsI detectors for measurement …


Avian Use Of Harvested Crop Fields During Spring Migration Through The Southern Drift Plains Of North Dakota, Alegra M. Galle, George M. Linz, William J. Bleier Feb 2004

Avian Use Of Harvested Crop Fields During Spring Migration Through The Southern Drift Plains Of North Dakota, Alegra M. Galle, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

In the Southern Drift Plains of North Dakota, land put into crop production has increased greatly over the last century. Of the approximately 70,000 square miles of land area in North Dakota, about 32,000 square miles are used for harvested cropland. Because of changes in the landscape, the diversity of habitat available for migrant birds has diminished, and migrants are now limited to choosing habitats for stopover sites that are uncharacteristic of those used at other times of the year. With reduced diversity of habitat a birds choice of feeding and resting areas greatly affects success at migration. Choice may …


Avian Use Of Harvested Crop Fields During Spring Migration Through The Southern Drift Plains Of North Dakota, Alegra M. Galle, George M. Linz, William J. Bleier Feb 2004

Avian Use Of Harvested Crop Fields During Spring Migration Through The Southern Drift Plains Of North Dakota, Alegra M. Galle, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

In the Southern Drift Plains of North Dakota, land put into crop production has increased greatly over the last century. Of the approximately 70,000 square miles of land area in North Dakota, about 32,000 square miles are used for harvested cropland. Because of changes in the landscape, the diversity of habitat available for migrant birds has diminished, and migrants are now limited to choosing habitats for stopover sites that are uncharacteristic of those used at other times of the year. With reduced diversity of habitat a birds choice of feeding and resting areas greatly affects success at migration. Choice may …


Iterated Belief Change, Aditya K. Ghose, P. O. Hadjinian, A. Sattar, J. You, R. Goebel Feb 2004

Iterated Belief Change, Aditya K. Ghose, P. O. Hadjinian, A. Sattar, J. You, R. Goebel

Faculty of Informatics - Papers (Archive)

Most existing formalizations treat belief change as a single step process, and ignore several problems that become important when a theory, or belief state, is revised over several steps. This paper identifies these problems, and argues for the need to retain all of the multiple possible outcomes of a belief change step, and for a framework in which the effects of a belief change step persist as long as is consistently possible. To demonstrate that such a formalization is indeed possible, we develop a framework which uses the language of PJ-default logic to represent a belief state, and which enables …


Cattail Quantification In The Prairie Pothole Region Of North Dakota Regarding Cattail Management For Reduction Of Blackbird Sunflower Damage, Scott T. Ralston, George M. Linz, William J. Bleier Feb 2004

Cattail Quantification In The Prairie Pothole Region Of North Dakota Regarding Cattail Management For Reduction Of Blackbird Sunflower Damage, Scott T. Ralston, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications


The spread of cattail across the Northern Great Plains has increased the amount of breeding and roosting habitat available to marsh-nesting blackbirds. In the fall, dense cattail stands attract large numbers of roosting blackbirds, that damage crops like sunflower. In an effort to disperse roosting blackbirds and reduce the resulting crop damage, scientists from the USDA’s National Wildlife Research Center and North Dakota State University have developed wetland habitat management techniques using a glyphosate-based aquatic herbicide. These techniques have been used by USDA Wildlife Services as a nonlethal method for reducing blackbird damage.

Previous research on individual wetlands has demonstrated …


Large-Scale Climate And Land Cover Influences On Blackbird Populations In The Prairie Pothole Region Of The United States And Canada, George M. Forcey, George M. Linz, William J. Bleier Feb 2004

Large-Scale Climate And Land Cover Influences On Blackbird Populations In The Prairie Pothole Region Of The United States And Canada, George M. Forcey, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

Blackbirds are ubiquitous members of the avian fauna in the Prairie Pothole Region of the United States and Canada. Their abundance combined with their food habitats make blackbirds significant agricultural pests on sunflower. Cost estimates for blackbird damage to sunflower in the northern Great Plains range from 4-11 million dollars per year. Because of their economic impact on agriculture, it is imperative to understand the environmental factors that influence their abundance. This study attempts to quantify the effects of landscape-level climatic and land use patterns on blackbird population dynamics in the Prairie Pothole Region of the United States and Canada.


Uv Perturbations In Brane Gas Cosmology, Scott Watson Feb 2004

Uv Perturbations In Brane Gas Cosmology, Scott Watson

Physics - All Scholarship

We consider the effect of the ultraviolet (UV) or short wavelength modes on the background of Brane Gas Cosmology. We find that the string matter sources are negligible in the UV and that the evolution is given primarily by the dilaton perturbation. We also find that the linear perturbations are well behaved and the predictions of Brane Gas Cosmology are robust against the introduction of linear perturbations. In particular, we find that the stabilization of the extra dimensions (moduli) remains valid in the presence of dilaton and string perturbations.


Optimal Sample Size For Multiple Testing: The Case Of Gene Expression Microarrays, Peter Muller, Giovanni Parmigiani, Christian Robert, Judith Rousseau Feb 2004

Optimal Sample Size For Multiple Testing: The Case Of Gene Expression Microarrays, Peter Muller, Giovanni Parmigiani, Christian Robert, Judith Rousseau

Johns Hopkins University, Dept. of Biostatistics Working Papers

We consider the choice of an optimal sample size for multiple comparison problems. The motivating application is the choice of the number of microarray experiments to be carried out when learning about differential gene expression. However, the approach is valid in any application that involves multiple comparisons in a large number of hypothesis tests. We discuss two decision problems in the context of this setup: the sample size selection and the decision about the multiple comparisons. We adopt a decision theoretic approach,using loss functions that combine the competing goals of discovering as many ifferentially expressed genes as possible, while keeping …


Boron Alloying In Gan, Gus L. W. Hart, Laurian Escalanti Feb 2004

Boron Alloying In Gan, Gus L. W. Hart, Laurian Escalanti

Faculty Publications

Using first-principles calculations in the local density approximation, we studied effects of adding up to 6% boron to zinc-blende GaN. We found that the band gap increases monotonically with boron incorporation, in agreement with experiment. A composition-independent band-gap bowing parameter of 4.30 eV was determined, and proved to be large compared to bowing for other mixed cation systems. The formation enthalpy of mixing, ΔH, was determined for BxGa1-xN, BxGa1-xAs, and GaAs1-xNx. A comparison of enthalpies indicates that the production of BxGa1-xN films with boron concentrations of at least 5% may be possible.


Model For A Partially Coherent Gaussian Beam In Atmospheric Turbulence With Application In Lasercom, Olga Korotkova, Larry C. Andrews, Ronald L. Phillips Feb 2004

Model For A Partially Coherent Gaussian Beam In Atmospheric Turbulence With Application In Lasercom, Olga Korotkova, Larry C. Andrews, Ronald L. Phillips

Physics Articles and Papers

Analytic expressions for the mutual coherence function (MCF) and the scintillation index of a partially coherent lowest order Gaussian beam wave propagating through the atmosphere (based on Kolmogorov spectrum model) are developed for the pupil plane of a receiving system. Partial coherence of the beam is modeled as a thin (complex) phase screen with Gaussian spectrum (Rytov theory and ABCD ray matrices are applied). The relation between the second- and fourth-order statistics for a beam with any degree of coherence in the atmosphere is introduced with the help of “effective” beam parameters, deduced from the free-space MCF. In particular, the …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 4, February 2004, College Of Engineering And Computer Science, Wright State University Feb 2004

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 4, February 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


Fish Stock And Fishery Enhancement In Western Australia. A Discussion Paper., Department Of Fisheries Feb 2004

Fish Stock And Fishery Enhancement In Western Australia. A Discussion Paper., Department Of Fisheries

Fisheries management papers

The objective of this paper is to propose a process that will allow the decision makers to objectively assess the appropriateness, benefits and costs of any stock enhancement proposal under Ecologically Sustainable Development (ESD) principles. To this end, this paper sets out a conceptual framework for assessment of stock enhancement projects, putting stock enhancement within the wider framework of fisheries and ecosystem management strategies, and their assessment, in Western Australia.


Subsurface Acidity, Mike Bolland, Chris Gazey, Amanda Miller, Dave Gartner, Julie-Anne Roche Feb 2004

Subsurface Acidity, Mike Bolland, Chris Gazey, Amanda Miller, Dave Gartner, Julie-Anne Roche

Bulletins 4000 -

Productive agriculture increases the concentration of hydrogen ions in soil, which acidifies the soil.

Aluminium is a component of many soil constituents, including clays and oxides, and is also present on the surfaces of soil organic matter. As the concentration of hydrogen ions in soil increases, soil pH decreases, and aluminium starts to dissolve from the soil constituents, increasing the concentration of aluminium ions in soil solution.

As the concentration of aluminium ions in the solution increases, the aluminium in the soil solution becomes increasingly toxic to plant roots, reducing root growth. The smaller amounts of plant roots explore a …


Non-Degenerate Normal-Mode Doublets In Vibrating Flat Circular Plates, Bradley M. Deutsch, Alexandra R. Robinson, Richard J. Felce, Thomas R. Moore Feb 2004

Non-Degenerate Normal-Mode Doublets In Vibrating Flat Circular Plates, Bradley M. Deutsch, Alexandra R. Robinson, Richard J. Felce, Thomas R. Moore

Student-Faculty Collaborative Research Publications

The vibrations of flat circular plates have been studied for hundreds of years, and they are well understood by the scientific community. Unfortunately, when vibrating circular plates are discussed in textbooks, the relationship between pairs of spatially orthogonal vibrational patterns that occur at each of the normal-mode frequencies is often ignored. Usually these orthogonal solutions are presented to the student as being degenerate in frequency; however, in practice the degeneracy of the doublet is often broken and the two spatially orthogonal solutions are separated in frequency. We show theoretically and experimentally that the degeneracy can be broken by a small …


Predicting Biodiversity Patterns In Deep Water Coral Ecosystems: Lessons From Phylogenetic Studies Of Shallow Water Coral Reef Crustacea, James Darwin Thomas Feb 2004

Predicting Biodiversity Patterns In Deep Water Coral Ecosystems: Lessons From Phylogenetic Studies Of Shallow Water Coral Reef Crustacea, James Darwin Thomas

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Comprehensive studies of coral reef biodiversity suggest that diversity patterns may be more congruent with geotectonic events than with the reigning paradigms of dispersal, center of origin, and vicariance. Geotectonic processes slowly accumulate taxa in areas exemplified by the presence of composite or lineage-based evolutionary diversity. This process-pattern model can suggest additional areas where similar patterns are likely to occur. Information on types and levels of diversity should be a primary concern in emerging conservation efforts for deepwater coral ecosystems. Current marine conservation efforts in shallow reef systems rely primarily on identifying “hotspots” that reflect measures of species richness and …


Detection Of Trace Amounts Of Explosives And/Or Explosive Related Compounds On Various Surfaces By A New Sensing Technique/Material., L. M. Dorozhkin, V A. Nefedov, Alexander G. Sabelnikov, V G. . Sevastjanov Feb 2004

Detection Of Trace Amounts Of Explosives And/Or Explosive Related Compounds On Various Surfaces By A New Sensing Technique/Material., L. M. Dorozhkin, V A. Nefedov, Alexander G. Sabelnikov, V G. . Sevastjanov

Alexander G Sabelnikov

No abstract provided.


A Log-Normal Distribution Model Of The Effect Of Bacteria And Ear Fenestration On Hearing Loss: A Bayesian Approach, Byron J. Gajewski, Jack D. Sedwick, Patrick J. Antonelli Feb 2004

A Log-Normal Distribution Model Of The Effect Of Bacteria And Ear Fenestration On Hearing Loss: A Bayesian Approach, Byron J. Gajewski, Jack D. Sedwick, Patrick J. Antonelli

Byron J Gajewski

Chronic ear infection is a potentially life-threatening illness that medical doctors typically treat with ear surgery. Despite the success of this treatment, complications can occur due to bacteria infection. Surgeons believe that this infection causes the patient to have clinically signigcant hearing damage. In order to understand such complications, surgeons must quantify the effect of bacteria, their toxins and ear surgery on hearing loss. To this end, the other two authors of this paper performed two experiments on guinea pigs to measure hearing thresholds following a bacterial infection and surgery of the inner ear. The response variable in these experiments …


Pictures From My Life With Polymer Science: Album 10, Otto Vogl Feb 2004

Pictures From My Life With Polymer Science: Album 10, Otto Vogl

Otto Vogl

No abstract provided.


Effect Of Measurement On The Periodicity Of The Coulomb Staircase Of A Superconducting Box, Jaan Männik, J. E. Lukens Feb 2004

Effect Of Measurement On The Periodicity Of The Coulomb Staircase Of A Superconducting Box, Jaan Männik, J. E. Lukens

Jaan Männik

We report on the effect of the backaction of a single Cooper pair transistor electrometer (E) on the charge state of a superconducting box (B). The charge is e periodic in the gate bias of B when E is operated near voltages 2Δ/e or 4Δ/e. We show that this is due to quasiparticle poisoning of B at a rate proportional to the number of quasiparticle tunneling events in E per second. We are able to eliminate this backaction and recover 2e-charge periodicity using a new measurement method based on switching-current modulation of E.

URL: http://link.aps.org/doi/10.1103/PhysRevLett.92.057004

DOI: 10.1103/PhysRevLett.92.057004


A Frame Bundle Generalization Of Multisymplectic Momentum Mappings, J Lawson Feb 2004

A Frame Bundle Generalization Of Multisymplectic Momentum Mappings, J Lawson

Mathematics Faculty Research

We construct momentum mappings for covariant Hamiltonian field theories using a generalization of symplectic geometry to the bundle LVϒ of vertically adapted linear frames over the bundle of field configurations ϒ. Field momentum observables are vector-valued momentum mappings generated from automorphisms of ϒ, using the (n + k)-symplectic geometry of LVϒ. These momentum observables on LVϒ generalize those in covariant multisymplectic geometry and produce conserved field quantities along flows. Three examples illustrate the utility of these momentum mappings: orthogonal symmetry of a Kaluza-Klein theory generates the conservation of field angular momentum, affine …


Self-Similarity And Symmetries Of Pascal’S Triangles And Simplices Mod P, Richard P. Kubelka Feb 2004

Self-Similarity And Symmetries Of Pascal’S Triangles And Simplices Mod P, Richard P. Kubelka

Faculty Publications

No abstract provided.


A Case Study Of Four Location Traces, Guanling Chen, David Kotz Feb 2004

A Case Study Of Four Location Traces, Guanling Chen, David Kotz

Computer Science Technical Reports

Location is one of the most important context information that an ubiquitous-computing application may leverage. Thus understanding the location systems and how location-aware applications interact with them is critical for design and deployment of both the location systems and location-aware applications. In this paper, we analyze a set of traces collected from two small-scale one-building location system and two large-scale campus-wide location systems. Our goal is to study characteristics of these location systems ant how these factors should be taken into account by a potentially large number of location-aware applications with different needs. We make empirical measurements of several important …


Application-Controlled Loss-Tolerant Data Dissemination, Guanling Chen, David Kotz Feb 2004

Application-Controlled Loss-Tolerant Data Dissemination, Guanling Chen, David Kotz

Computer Science Technical Reports

Reactive or proactive mobile applications require continuous monitoring of their physical and computational environment to make appropriate decisions in time. These applications need to monitor data streams produced by sensors and react to changes. When mobile sensors and applications are connected by low-bandwidth wireless networks, sensor data rates may overwhelm the capacity of network links or of the applications. In traditional networks and distributed systems, flow-control and congestion-control policies either drop data or force the sender to pause. When the data sender is sensing the physical environment, however, a pause is equivalent to dropping data. Arbitrary data drops are not …


A Demonstration Of Phonons That Implements The Linear Theory, Dietrich Lüerßen, Nalini Easwar, Ayesha Malhotra, Libby Hutchins, Kim Schulze, Brandi Wilcox Feb 2004

A Demonstration Of Phonons That Implements The Linear Theory, Dietrich Lüerßen, Nalini Easwar, Ayesha Malhotra, Libby Hutchins, Kim Schulze, Brandi Wilcox

Physics: Faculty Publications

Beads on a vibrating wire are used to simulate the discrete structure of a solid-state material. The novel idea of the experiment is to use very small oscillation amplitudes of the wire to avoid nonlinearities in the interaction. We achieve a good signal-to-noise ratio using a lock-in technique. We find quantitative agreement between theory and experiment for not only a mono- and a diatomic chain, but also for the bare wire. The latter agreement is the crucial aspect that distinguishes our experiment from previous ones. This agreement assures that the fundamental assumption of the theory ~Hooke’s law! is satisfied. We …


The Hardy Inlet Estuarine Fishery Management Issues And Options, Department Of Fisheries Feb 2004

The Hardy Inlet Estuarine Fishery Management Issues And Options, Department Of Fisheries

Fisheries management papers

This paper presents information available on fish resources in the Hardy Inlet/Blackwood River system, and discusses the key management matters and likely impacts of a number of possible management measures.


On The Solar Wind Control Of Cusp Aurora During Northward Imf, M. G. Bobra, S. M. Petrinec, S. A. Fuselier, E. S. Claflin, Harlan E. Spence Feb 2004

On The Solar Wind Control Of Cusp Aurora During Northward Imf, M. G. Bobra, S. M. Petrinec, S. A. Fuselier, E. S. Claflin, Harlan E. Spence

Physics & Astronomy

[1] The location of cusp aurora during northward interplanetary magnetic field (IMF) conditions and the solar wind control of that location are explored. The cusp aurora is imaged by the Imager for Magnetopause-to-Aurora Global Exploration's (IMAGE) Far Ultraviolet Instrument (FUV). Predicted locations of the cusp aurora were computed by assuming anti-parallel reconnection between the observed IMF orientation and the 1996 Tsyganenko model magnetopause magnetic field. While the majority of anti-parallel reconnection sites tailward of the cusp, when mapped to the ionosphere, coincide with the observed cusp aurora, the anti-parallel merging hypothesis cannot explain certain aspects of the observations, including its …


Characterizing Overlay Multicast Networks And Their Costs, Sonia Fahmyl, Minseok Kwon Feb 2004

Characterizing Overlay Multicast Networks And Their Costs, Sonia Fahmyl, Minseok Kwon

Department of Computer Science Technical Reports

No abstract provided.


Anonymizing Web Services Through A Club Mechanism With Economic Incentives, Mamata Jenamani, Leszek Lilien, Bharat Bhargava Feb 2004

Anonymizing Web Services Through A Club Mechanism With Economic Incentives, Mamata Jenamani, Leszek Lilien, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.


Change Tolerant Indexing For Constantly Evolving Data, Reynold Cheng, Yuni Xia, Sunil Prabhakar, Rahul Shah Feb 2004

Change Tolerant Indexing For Constantly Evolving Data, Reynold Cheng, Yuni Xia, Sunil Prabhakar, Rahul Shah

Department of Computer Science Technical Reports

No abstract provided.