Physical Sciences and Mathematics Commons^™

Salinity History Of Coastal Marshes Reconstructed From Diatom Remains, Michael L. Parsons, Quay Dortch, R. Eugene Turner, Nancy N. Rabalais

Faculty Publications

Sediment cores were collected from three Louisiana coastal marsh ponds, dated with radioisotopes, and analyzed for diatom remains to determine if long-term salinity changes were evident in the sediment record. A diatom-based salinity index formulated from a statistical comparison of available salinity data and changing diatom assemblages demonstrated that diatom remains appear to preserve salinity signals in coastal brackish and salt marsh environments. The salinity index was applied to sediment cores spanning the late 1600s to the 1990s and provided a more complete record of salinity than field data, which were temporally and spatially incomplete. The salinity reconstructions indicated that …

Work In Progress: Automating Proportion/Period Scheduling, David Steere, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

The recent effort to define middleware capable of supporting real-time applications creates the opportunity to raise the level of abstraction presented to the programmer. We propose that proportion/period is a better abstraction for specifying resource needs and allocation than priorities. We are currently investigating techniques to address some issues that are restricting use of proportion/period scheduling to research real-time prototypes. In particular, we are investigating techniques to automate the task of selecting proportion and period, and that allow proportion/period to incorporate job importance under overload conditions.

Vol. 22 No. 3-4 (1999): Pacific Studies Full Issue, The Jonathan Nāpela Center For Hawaiian And Pacific Islands Studies

Pacific Studies

Pacific Studies is published two times a year by The Jonathan Nāpela Center for Hawaiian and Pacific Studies, Brigham Young University Hawai‘i #1979, 55–220 Kulanui Street, Lāʻie, Hawai‘i 96762, but responsibility for opinions expressed in the articles rests with the authors alone. Subscription rate is US$40.00 yearly, payable to The Jonathan Nāpela Center for Hawaiian and Pacific Studies. The Jonathan Nāpela Center for Hawaiian and Pacific Studies (formerly The Pacific Institute) is an organization funded by Brigham Young University Hawai‘i. The Center assists the University in meeting its cultural and educational goals by undertaking a program of teaching, research, and …

Notes From The Director, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Acknowledgements, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Full Issue, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Bulletin 4385 - Control Of Mediterranean Fruit Fly (Medfly) In Commercial Orchards, Sonya Broughton, Francis De Lima

Bulletins 4000 -

The Mediterranean fruit fly (Medfly) is thought to originate from tropical Africa. It is a pest in many areas of the world including Western Australia. It was first detected at Claremont in 1895 and is now found as far south as Esperance and as far north as Derby. The main area of infestation extends from Carnarvon to Bunbury.

Medfly is known to infest over 200 fruit and vegetable species. In Western Australia, stone fruit, pome fruit, citrus, guavas, figs and loquats are particularly susceptible.

Intelligent Visualization And Automated Processing For Large Scale Geographic Information Systems, Yu Jiang

All-Inclusive List of Electronic Theses and Dissertations

This research focuses on developing a new output system that compacts maps in multiple projections into a single Geographic Information System (GIS) without visual errors, through constructing a discrete GIS database that is managed by a Relational Data Base Management System (RDBMS). Unlike in a traditional large GIS database, the data are "physically discrete but logically continuous." In a new discrete GIS database, every map keeps its individuality without a relationship to any other map, and the relationships among the maps are centrally managed by a RDBMS. A study site was chosen at the boundary of the state of Indiana …

Wildlife-Caused Losses For Producers Of Channel Catfish Ictalurus Punctatus In 1996, Alice P. Wywialowski

United States Department of Agriculture Wildlife Services: Staff Publications

The National Agricultural Statistics Service surveyed by telephone and mail in January and February 1997 all known producers of channel catfish Ictalurus punctatus to acquire current information about wildlife-caused losses in calendar year 1996. Many producers tried to prevent wildlife-caused losses of their catfish by shooting (57%), vehicle patrol (55%), or frightening (36%), at an estimated cost of >$5 million. Yet, 69% of catfish produces cited some wildlife-caused losses. Birds were most frequently cited as a cause of losses, and double-crested cormorants Phalacrocorax auritus was the species cited most frequently (53%). The next most frequently cited bids were herons Ardea …

The Effect Of Divalent Cations On The Prophenoloxidase Enzyme Cascade Activity In The Freshwater Crayfish Cambarus Latimanus, Hans Skailand Eikaas

Theses and Dissertations

The effect of divalent cations such as cadmium, calcium, copper, lead and magnesium upon the prophenoloxidase system (proPO) was studied in hemocytes of the crayfish Cambarus latimanus. It was demonstrated that cadmium, calcium, copper and lead increased proPO activity significantly, whereas magnesium had no statistically significant effect on the system. Also, the molecular weight of the proPO enzyme was estimated using SDS-PAGE and found to be approximately 76 kDa.

The Probe, Issue 207 – December 1999

The Probe: Newsletter of the National Animal Damage Control Association

NADCA: A Proud History, A New Future -- Robert H. Schmidt, President, NADCA
Position Announcement: WILDLIFE ECOLOGIST - Urban Wildlife & Urban-Human Conflict Management Illinois Natural History Survey, Urbana-Champaign, IL
In Memoriam: Guy R. Hodge
Personnel Changes in USDA Wildlife Services: Two new State Directors
Book review: "Wildlife of the New Millennium: A Field Guide" by Buck Peterson. Published by Longstreet Press, Marietta, Georgia 1999. (152 pages, illustrated. $11.95) ISBN 1-56352-546-1
Euthanasia Chamber Available from Pioneer Wildlife Control of Westwood, MA

Abstracts from the 6th Annual Conference of The Wildlife Society - September 1999, Austin, TX
Public health significance of …

Characterizations Of Classes Of Programs By Three-Valued Operators, Anthony K. Seda, Pascal Hitzler

Computer Science and Engineering Faculty Publications

Several important classes of normal logic programs, including the classes of acyclic, acceptable, and locally hierarchical programs, have the property that every program in the class has a unique two-valued supported model. In this paper, we call such classes unique supported model classes. We analyse and characterize these classes by means of operators on three-valued logics. Our studies will motivate the definition of a larger unique supported model class which we call the class of Phi-accessible programs. Finally, we show that the class of Phi -accessible programs is computationally adequate in that every partial recursive function can be implemented by …

Oxygen Pressure-Tuned Epitaxy And Optoelectronic Properties Of Laser-Deposited Zno Films On Sapphire, S. Choopun, R. D. Vispute, W. Noch, A. Balsamo, R. P. Sharma, T. Venkatesan, A. Iliadis, David C. Look

Physics Faculty Publications

Influence of oxygen pressure on the epitaxy, surface morphology, and optoelectronic properties has been studied in the case of ZnO thin films grown on sapphire ~0001! by pulsed-laser deposition. Results of Rutherford backscattering and ion channeling in conjunction with atomic force microscopy clearly indicate that the growth mode, degree of epitaxy, and the defect density strongly depend on the oxygen background pressure during growth. It is also found that the growth mode and the defects strongly influence the electron mobility, free-electron concentration, and the luminescence properties of the ZnO films. By tuning the oxygen pressure during the initial and the …

Trace-Level Determination Of Fluorescently Labeled Phenoxy Acid Herbicides And The Study Of Their Crop Uptake And Soil Accumulation, Noura Saeed Al Nuaimi

Theses

A challenging problem facing the determination of phenoxy acid herbicides in samples is their low UV absorptivity and the interference associated with the matrix in which these analytes exist. This thesis is concerned with improving the detection limits of this group of herbicid as well as reduce or eliminate interference associated with the sample matrix.

Native phenoxy acid herbicides could be analyzed by high performance liquid chromatography (HPLC) with ultraviolet detection. Phenoxy herbicides were analyzed by HPLC employing a gradient conditions that allowed baseline resolution of all analytes used in this study in approximately 20 min. However, the average detection …

Characterisation Of The Effects Of Time And Pressure On A Group Of Electronic Voltage Standards, James Kevin Armstrong

Masters

Although primary metrology laboratories use standards based on the Josephson effect to maintain a local reference standard for dc voltage, artefact standards are still the standard of choice in many secondary laboratories. The National Metrology Laboratory, Dublin maintains a local reference standard for dc voltage by means of an ensemble of Zener-diode based electronic voltage standard units. Electronic voltage standards have a number of shortcomings over Josephson standards for use as a local reference standard. In particular their output voltages are influenced by several external factors. In order to make optimum use of the NML reference standard it is important …

A Hierarchy Of Maps Between Compacta, Paul Bankston

Mathematics, Statistics and Computer Science Faculty Research and Publications

Let CH be the class of compacta (i.e., compact Hausdorff spaces), with BS the subclass of Boolean spaces. For each ordinal α and pair $\langle K,L\rangle$ of subclasses of CH, we define Lev_≥α K,L), the class of maps of level at least α from spaces in K to spaces in L, in such a way that, for finite α, Lev_≥α (BS,BS) consists of the Stone duals of Boolean lattice embeddings that preserve all prenex first-order formulas of quantifier rank α. Maps of level ≥ 0 are just the continuous surjections, and the maps of level ≥ 1 are …

Initial State Dependence Of Low-Energy Electron Emission In Fast Ion Atom Collisions, Robert Moshammer, Pablo Daniel Fainstein, Michael Schulz, Wayne M. Schmitt, Holger Kollmus, Rido Mann, Siegbert Hagmann, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

Single and multiple ionization of neon and argon atoms by 3.6 MeV/u Au⁵³⁺ impact has been explored in kinematically complete experiments. Doubly differential cross sections for low-energy electron emission have been obtained for a defined charge state of the recoiling target ion and the receding projectile. Observed target specific structures in the electron continuum are attributable to the nodal structure of the initial bound state momentum distribution. The experimental data are in excellent accord with continuum-distorted-wave eikonal-initial-state single ionization calculations if multiple ionization is considered appropriately.

Applications And Algorithms For Least Trimmed Sum Of Absolute Deviations Regression, Douglas M. Hawkins, David Olive

Articles and Preprints

High breakdown estimation (HBE) addresses the problem of getting reliable parameter estimates in the face of outliers that may be numerous and badly placed. In multiple regression, the standard HBE's have been those defined by the least median of squares (LMS) and the least trimmed squares (LTS) criteria. Both criteria lead to a partitioning of the data set's n cases into two “halves” – the covered “half” of cases are accommodated by the fit, while the uncovered “half”, which is intended to include any outliers, are ignored. In LMS, the criterion is the Chebyshev norm of the residuals of the …

Measurement Of The B0B̅0 Oscillation Frequency Using L-D*+ Pairs And Lepton Flavor Tags, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

The oscillation frequency Δm_d of B⁰B̅⁰ mixing is measured using the partially reconstructed semileptonic decay B̅⁰→l^- ν̅ D^*+X. The data sample was collected with the CDF detector at the Fermilab Tevatron collider during 1992–1995 by triggering on the existence of two lepton candidates in an event, and corresponds to about 110 pb^-1 of p̅p collisions at √s =1.8 TeV. We estimate the proper decay time of the B̅⁰ meson from the measured decay length and reconstructed momentum of the l^-D^*+ system. The charge of …

Estimating The Probability Of Severe Convective Storms: A Local Perspective For The Central And Northern Plains, Preston W. Leftwich Jr.

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

Summary and Conclusions

A procedure to estimate probabilities of the occurrence of severe convective storms within local areas has been described. Probabilities were based on a simulated climatology and the relative frequency of severe convective events when a selected site was contained within an operational Outlook or Watch. Combined data from five local areas were used to develop a general model for local probabilities within the central and northern Plains region. Attachment of probabilities to specific products placed values within a framework familiar to both forecasters and "end-users." Application of results in an operational scenario demonstrated representative local probabilities and …

Water Current, Volume 31, No. 6, December 1999

Water Current Newsletter

Conference to Develop a Management Agenda for Nebraska's Water Future
From the Director: We Have a Long Way, But We Need to Go Further; Water Center Recognized as "Groundwater Guardian" Partner
NU Research Faculty Voice Desires for Strong Water Center Leadership
Citizen Stewards of the Pines and Plains
Fourth Water Tabloid Now Available from NU
Water News Briefs
Sixth Annual Undergrad Research Conference
Publications
National Geographic Society Awarding Science Grants
Call for Papers: Spatial Symposium in Reno, Nevada
Call for Papers: 11th Platte River Basin Symposium
Cooperation and Tension: The History, Reality and Future of Nebraska's Interstate Agreements

Introduction: Defining And Understanding Sustainability In Small Island States, Charles J. Stevens

Pacific Studies

No abstract provided.

The Sustainable, The Expendable, And The Obsolete, Michael D. Lieber

Pacific Studies

This is a preliminary exploration of the concept of sustainability and its potential usefulness to anthropologists. “Sustainable” is distinguished from “stable” and “viable” in terms of its implications of directionality of time, pointing both backward and forward. Given the time implications, the contexts of “sustainable Xs” (technology, activity, development, etc.) are crucial to explaining what happened to X in the past and prognosticating its future. The argument is illustrated by analyzing data on obsolete fishing practices on Kapingamarangi Atoll (Federated States of Micronesia), focusing on the contexts of change in political /religious organization in the twentieth century. Changing access to …

Development, Sustainability, And The Deforestation Of Samoa, Paul Shankman

Pacific Studies

The forests of Samoa (formerly Western Samoa) are rapidly disappearing. This article reviews the history of Samoan deforestation, particularly during the last four decades, in the context of ideas about development and sustainability. It also examines the role of village agriculturalists in the process of deforestation. Recent economic, technological, and organizational changes have increased village agricultural expansion and, consequently, deforestation.

Alkyl Nitrates During The Prophet ’98 Summer Intensive, Kristi A. Ostling

Masters Theses

As part of the PROPHET intensive held at the University of Michigan Biological Station in northern Michigan, a gas chromatography system for making fast-turnaround measurements of C1 to C5 alkyl nitrates was developed and deployed from July 19 to August 21, 1998. Every 30 minutes, samples were automatically acquired on a small Tenax trap made from silicosteel column and injected on a GC column by thermal desorption prior to ECD detection. Tests performed to measure breakthrough and on-trap destruction indicated no breakthrough for C3, C4, and C5 nitrates and excellent stability for these compounds on the trap. Chromatographic resolution of …

Stratigraphic Analysis Of Diamicton Units In North-Central St. Joseph County, Michigan, Andrew C. Flint

Masters Theses

Seven subsurface glacial diamicton units, including a paleosol, have been characterized from two borings in north-central St. Joseph County, Michigan. These units have been characterized in terms of their clay mineralogy, texture, color, and stratigraphic position. t-Tests confirm that each unit displays a significant difference in mean 7A/10A peak height ratio from all other units.

Unit 4, informally called the Gray Marker tilt has been correlated between borings in this study and to the findings of others (Gardner, 1997, Nicks, in preparation). The Newbury till described by the Indiana Geological Survey (unpublished data) may also correlate to Unit 4, raising …

On-Line Bayesian Tree-Structured Transformation Of Hidden Markov Models For Speaker Adaptation, Shaojun Wang, Yunxin Zhao

Kno.e.sis Publications

This paper presents a new recursive Bayesian learning approach for transformation parameter estimation in speaker adaptation. Our goal is to incrementally transform (or adapt) the entire set of HMM parameters for a new speaker or new acoustic enviroment from a small amount of adaptation data. By establishing a clustering tree of HMM Gaussian mixture components, the finest affine transformation parameters for individual HMM Gaussian mixture components can be dynamically searched. The on-line Bayesian learning technique proposed in our recent work is used for recursive maximum a posteriori estimation of affine transformation parameters. Speaker adaptation experiments using a 26-letter English alphabet …

Stellar Angular Diameters Of Late-Type Giants And Supergiants Measured With The Navy Prototype Optical Interferometer, Tyler E. Nordgren, M. E. Germain, J. A. Benson, D. Mozurkewich, Jeffrey J. Sudol, N. M. Elias Ii, Arsen R. Hajian, N. M. White, D. J. Hutter, K. J. Johnston, F. S. Gauss, J. T. Armstrong, T. A. Pauls, L. J. Rickard

Physics & Engineering Faculty Publications

No abstract provided.

Molecular-Dynamics Study Of Phase Transitions In Alkali Azides, M. M. Ossowski, John R. Hardy, Robert W. Smith

Physics Faculty Publications

An account is presented of our studies of the order-disorder phase transitions in KN₃, RbN₃, and CsN₃. These are based on parameter-free interionic potentials based on the Gordon-Kim modified electron-gas formalism extended to molecular ions. We performed static structural relaxations and supercell molecular dynamics and predicted with reasonable accuracy the temperatures for the onset of the transitions. In particular, we address the question of how the N₃^- ions reorient to yield the transitions. We found the existence of NaCl-type high-temperature phases in disordered KN₃ and RbN₃ and argue that this …

Calibration, Installation Techniques, And Initial Measurements For Vertical Resistivity Probes Used In Hydrogeologic Investigations, Jeffrey Mark Groncki

Masters Theses

Vertical Resistivity Probes (VRPs) are being increasingly used in a variety of applications where detailed vertical resistivity information in both the vadose and saturated zones is needed. All the different possible array types and spacings must be calibrated for the effect of the 2" (outer diameter) insulating PVC cylinder on which the electrodes are mounted. Apparent resistivities must be corrected by calibration factors. Varying the installation parameters greatly influences the measured apparent resistivity because of the disturbed annulus and the composition of the backfill materials. Bentonite slurry is necessary for the installations to keep the electrodes in good contact with …