Digital Commons Network^™

Complex Dynamics And Multistability In A Damped Harmonic Oscillator With Delayed Negative Feedback, Sue Ann Campbell, Jacques Bélair, Toru Ohira, John Milton

WM Keck Science Faculty Papers

A center manifold reduction and numerical calculations are used to demonstrate the presence of limit cycles, two-tori, and multistability in the damped harmonic oscillator with delayed negative feedback. This model is the prototype of a mechanical system operating with delayed feedback. Complex dynamics are thus seen to arise in very plausible and commonly occurring mechanical and neuromechanical feedback systems.

Water Current, Volume 27, No. 6, December 1995

Water Current Newsletter

Buffer Strips Trap Contaminants
From the Director: Lack of Call of Proposals Sign of Politics at Work
Riparian Buffer Strips Prevent Pollution
Might Missouri Conference Topic
Manure Application Studied
Research Brief: A Multivariate Index Methodology for Landfill Site Characterization Using Geophysics and Geostatistics
Nebraska Water News
Guide for Sealing Wells Available from UNL
Symposium Focuses on Integrated Approach
Booklet Helps Find Water Information
Speaker Compares Public, Technical Views
Drijber Gets Into Microbial Communities
Dishrags Breeding Ground for Bacteria
Seminar Series to Present Views on Platte River Management

The Probe, Issue 161 – December 1995

The Probe: Newsletter of the National Animal Damage Control Association

Animal Activists Take Bear Issues to Idaho, Michigan, Massachusetts, and Washington
Canada Geese Almost "Get" Gingrich
Egrets Causing Health Hazards in Oklahoma
Pigeons Hitch a Ride In London
Book Review: Variations of the Flat Set, by Charles Dobbins. 1995. Sullivan Productions, Blue Creek, OH. 78 pages.
New Trapping Laws in Colorado

Dispersal Dynamics In A Wind-Driven Benthic System, John A. Commito, S. F. Thrush, R. D. Pridmore, J. E. Hewitt, V. J. Cummings

Environmental Studies Faculty Publications

Bedload and water column traps were used with simultaneous wind and water velocity measurements to study postlarval macrofaunal dispersal dynamics in Manukau Harbour, New Zealand. A 12-fold range in mean wind condition resulted in large differences in water flow (12-fold), sediment flux (285-fold), and trap collection of total number of individuals (95-fold), number of the dominant infaunal organism (84-fold for the bivalve Macomona liliana), and number of species (4-fold). There were very strong, positive relationships among wind condition, water velocity, sediment flux, and postlarval dispersal, especially in the bedload. Local density in the ambient sediment was not a good predictor …

The Prairie Naturalist Volume 27, No.4 December 1995

The Prairie Naturalist

NEW DISTRIBUTIONAL RECORDS FOR MAMMALS IN KANSAS · D. W Sparks and J. R. Choate

CLAY-COLORED SPARROWS IN NORTH DAKOTA PARASITIZED BY BROWN-HEADED COWBIRDS ▪ G. P. Romig and R. D. Crawford

A NOTEWORTHY RECORD AND THE BREEDING DISTRIBUTION OF THE BLUE GROSBEAK IN NORTH DAKOTA ▪ L. D. Igl

NEAR LONGEVITY RECORD FOR THE SNOW GOOSE ▪ M T. Koenen and D. M. Leslie, Jr.

COMPARISON OF WATER CONSUMPTION BETWEEN TWO GRASSLAND EMBERIZIDS ▪ J. L. Zimmerman

FACTORS ASSOCIATED WITH DECLINING PROPORTION OF CITIZENS HUNTING IN SOUTH DAKOTA ▪ N. J. Dietz, K. F. Higgins, and R. D. Mendelsohn …

The Variability Of Carbon Dioxide In The Vadose Zone, John J. Ring

Masters Theses

The purpose of this thesis was to observe and attempt to explain the variations of carbon dioxide in the vadose zone of a nature area in southwestern Michigan. Well nests, consisting of discrete soil gas sampling points and temperature probes set at depths ranging from 3 to 53 feet, were constructed in a sandy, glacial outwash plain. Soil samples were collected for analysis of organic carbon content during installation. Soil gas samples were collected periodically from June, 1992 to March, 1993 and analyzed for CO₂ and O₂ concentrations. Occasionally, samples were collected and analyzed for isotopic C^{13 …}

A System Dynamics Approach To Modelling The Degradation Of Biochemical Oxygen Demand In A Constructed Wetland Receiving Stormwater Runoff, Leslie A. Mudgett

Theses and Dissertations

The objective of this research was to develop a tool to aid the Air Force Environmental Manager in the identification of the design parameters of a constructed wetland system that may be optimized to provide a desired biochemical oxygen demand (BOD) removal efficiency during the treatment of Air Force stormwater runoff. The objective is achieved through the development and use of a system dynamics model which simulates the hydrological functions of a constructed wetland as well as the processes within the wetland responsible for degradation of BOD. Based on literature review, the primary mechanism responsible for the degradation of BOD …

The Separation Of Aqueous Iron Species Found In Stepwise Complexation By Capillary Electrophoresis With Atomic Absorption Spectroscopy Detection, Robert E. Sutton

Dissertations

A capillary zone electrophoresis system was interfaced to an atomic absorption spectrom eter to permit the separation and detection o f various species of iron found in step wise complexation in aqueous solutions. The samples were introduced at the anodic end of the column employing the electroosmotic flow to drive all the species to the detector at the cathodic end. Aqueous solutions of iron(II) and iron (III) chloride salts were among the compounds studied. The buffer employed w as a 20 millimolar (2-[N-morpholino]ethanesulfonic acid adjusted to a pH of 6 with 6 .6 millimolar potassium hydroxide. The detection limit was …

The Anomalous Mössbauer Fraction Of Ferritin And Polysaccharide Iron Complex (Pic), M. E. Y. Mohie-Eldin, Richard B. Frankel, L. Gunther, G. C. Papaefthymiou

Physics

Mössbauer studies of the ubiquitous protein molecule ferritin and its synthetic "biomimic" polysaccharide iron complex (PIC) exhibit an anomaly in the Mössbauer spectrum wherein the recoil free fraction f-factor has a sharp drop with respect to temperature as the temperature rises above 30 K for mammalian ferritin and 60 K for PIC. The anomaly coincides with the disappearance of hyperfine splitting, which is due to superparamagnetic relaxation above the blocking temperature. Different absorbers were used to experimentally investigate the effect of absorber thickness on the Mössbauer spectrum. The anomaly persists for thin absorbers. Also, spectra treated with FFT procedures …

Soil Acidity. A Reference Manual., Linda Leonard, Mike D. Bolland

Natural resources published reports

This publication is intended as a guide for consultants, development officers and field representatives for the extension of soil acidity in Western Australia.

Most Western Australian soils are naturally acidic. Acid peaty sands in the high rainfall area of the South West are the only W.A. soils in which natural acidity has been treated routinely before productive agriculture was introduced. There are approximately 100, 000 hectares of acid, peaty sands scattered through coastal districts between Pemberton and Rocky Gully districts.

Pattern Matching Image Compression: Algorithmic And Empirical Results, Mikhail J. Atallah, Yann Génin, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

Inverse Pattern Matching, Amihood Amir, Alberto Apostolico, Moshe Lewenstein

Department of Computer Science Technical Reports

No abstract provided.

Regulation Of The Expression Of Lipogenic Enzymes By Insulin-Mimetics, Juiyu Wu

Masters Theses

Many researchers have shown that selenate (SeO₄^2-) and vanadate (VO₄^2-) have insulin-mimetic effects in certain biological processes. These mimetic effects include increasing glucose transport, regulating glycolytic enzymes, normalizing plasma glucose levels and activities of insulin regulated enzymes in diabetic rats. To clarify the functions and roles of these insulin-mimetics in different insulin-regulated metabolic pathways, the expression of the genes for glucose-6-phosphate dehydrogenase (G6PDH) and fatty acid synthase (FAS) were investigated. G6PDH is a key enzyme in the pentose phosphate pathway and is also involved in lipogenic metabolism by providing 55-70% of the NADPH utilization …

Effects Of Insulin And Insulin Mimetics On Antioxidant Enzyme Levels: In Vivo And In Vitro, Shikha Varma

Masters Theses

Tissue antioxidation status is considered to be an important factor for elucidating the etiology of diabetes and its physiological complications. This study was aimed to determine the in vivo antioxidant enzyme levels in the altered antioxidant status of diabetic rat liver with the treatment of two potent insulin mimetics, vanadium and selenate. The direct effects of vanadate, selenate, and zinc (another insulin mimetic) on the antioxidant enzyme levels in primary rat hepatocytes in culture was also determined. Levels of superoxide dismutase (SOD), catalase (CAT) and gluthahione peroxidase (GPX) were determined in both model systems.

In the vivo model, insulin treatment …

The Application Of Hybridized Genetic Algorithms To The Protein Folding Problem, Robert L. Gaulke

Theses and Dissertations

The protein folding problem consists of attempting to determine the native conformation of a protein given its primary structure. This study examines various methods of hybridizing a genetic algorithm implementation in order to minimize an energy function and predict the conformation (structure) of Met-enkephalin. Genetic Algorithms are semi-optimal algorithms designed to explore and exploit a search space. The genetic algorithm uses selection, recombination, and mutation operators on populations of strings which represent possible solutions to the given problem. One step in solving the protein folding problem is the design of efficient energy minimization techniques. A conjugate gradient minimization technique is …

Semantic Interpretation Of An Artificial Neural Network, Stanley D. Kinderknecht

Theses and Dissertations

Recent advances in machine learning theory have opened the door for applications to many difficult problem domains. One area that has achieved great success for stock market analysis/prediction is artificial neural networks. However, knowledge embedded in the neural network is not easily translated into symbolic form. Recent research, exploring the viability of merging artificial neural networks with traditional rule-based expert systems, has achieved limited success. In particular, extracting production (IF.. THEN) rules from a trained neural net based on connection weights provides a valid set of rules only when neuron outputs are close to 0 or 1 (e.g. the output …

Study Of The Long-Term Desorption Of Trichloroethylene From Clay Soils Using Infrared Spectroscopy, Mary P. Stager

Theses and Dissertations

Slow desorption of contaminants from soil presents one of the greatest challenges to modeling contaminant fate and transport and implementing effective remediation technologies. The kinetics of long-term desorption of trichloroethylene (TCE) from powdered clay soils were studied to determine the desorption rates and mechanism. Infrared absorption spectroscopy was used to monitor the concentration of TCE desorbed from contaminated flint clay for 71 hours. Observed gas phase TCE concentrations as a function of time were compared to that predicted by a one-site Langmuir desorption mechanism. The Langmuir model, with a single type of bonding site, did not account for the release …

A Comparison Of Remediation Priorities Developed By The Defense Priority Model, The Relative Risk Evaluation Method, And A Quantitative Risk Assessment Approach, David M. Hunter

Theses and Dissertations

The Superfund, established by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, seriously underestimated both the number of severely contaminated sites and the associated cleanup cost. The magnitude of projected cleanup costs, coupled with shrinking federal budgets, necessitated the development and use of risk-based prioritization models among some federal agencies. Among these tools, the DOD prioritization models are meant to give priority to sites posing the greatest threat to human health. Their failure to properly rank sites could incorrectly shift the focus from those that pose substantial risk to sites of lesser risk. The DOD site ranking …

Comparison Of Gravel Substrate Vs Soil Substrate For The Construction Of An Experimental Fen, Carolyn S. Langley

Theses and Dissertations

Under the Clean Water Act Section 404 of 1972 and 33 CFR 320-330 and 40 CFR 230 moderate the destruction of wetlands by the Air Force to make way for other uses. To obtain a permit for a design or construction project which affects a wetland, the Air Force must agree to create new wetlands, or replace lost wetland acreage through wetland creation or restoration. The Air Force is interested in building 'successful' wetlands as inexpensively as possible. It has been common practice to use hydric soil, which often had to be hauled in, as the substrate at the restored …

Temporal Influence On Awareness, Don E. Hill

Theses and Dissertations

Grossberg's Motion Oriented Contrast Filter (MOC) was extensively analyzed (7). The output from the filter's "global motion" neuronal layer was compared to a noncausal post-processing filter developed by AFIT. Both filters were shown to incorporate a weighted, noncausal temporal range of input data in processed output. The global motion framework was then implemented using a physiologically motivated pulsed neural model - the Pulse Coupled Neural Network (PCNN). By incorporating both spatial and temporal data, the PCNN was shown to exhibit a common visual illusion, apparent motion. The existence of a physiological temporal processing range was further investigated through implementation of …

A Neural Network Approach To The Prediction And Confidence Assignation Of Nonlinear Time Series Classifications, Erin S. Heim

Theses and Dissertations

This thesis uses multiple layer perceptrons (MLP) neural networks and Kohonen clustering networks to predict and assign confidence to nonlinear time series classifications. The nonlinear time series used for analysis is the Standard and Poor's 100 (S&P 100) index. The target prediction is classification of the daily index change. Financial indicators were evaluated to determine the most useful combination of features for input into the networks. After evaluation it was determined that net changes in the index over time and three short-term indicators result in better accuracy. A back-propagation trained MLP neural network was then trained with these features to …

A Sweet Home No More?: The Future For Habitat Protection Under The Endangered Species Act, Federico Cheever, Murray D. Feldman, University Of Colorado Boulder. Natural Resources Law Center

A Sweet Home No More?: The Future for Habitat Protection Under the Endangered Species Act (November 29)

20 pages.

Includes bibliographical references and biographical information for Federico Cheever and Murray D. Feldman.

Contents:

Babbitt v. Sweet Home Chapter of Communities for a Greater Oregon / Federico Cheever -- The Sweet Home decision and private property issues / Murray D. Feldman -- Memorandum of Agreement between the State of Colorado and the Department of the Interior concerning programs to manage Colorado's declining native species

The U.S. Supreme Court decision in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon,115 S.Ct. 2407 (1995), held that the Department of the Interior reasonably construed Congress' intent when it included …

Genetic Epidemilogical Analysis Of Complex Disorders., Swapan Nath Dr.

Doctoral Theses

The present study can be broadly classified in the area of genetic epidemiology, which is conventionally defined as a science that deals with the aetiology, distribution, and control of disease in groups of relatives and with inherited causes of disease in populations (Morton 1982, 1993). One of the major goals of genetic epidemiology is the study of the nature and extent of clustering of a disease in families and in defined ethnic groups. The study of a disorder within the genetic epidemiological framework is performed by testing :(1) whether the disorder clusters in families?(2) whether observed familiarity is caused by …

On Texture Image Analysis Using Fractal Geometry Based Features., Nirupam Sarkar Dr.

Doctoral Theses

Visual textureTexture is a property to characterize a region of a scene. A set of natural texture images is shown in Fig. 1.1. A specific texture may be generated due to certain organization of several objects in a region, or due to the reflectance pattern caused by color variation or unevenness of an object surface. Since texture provides a lot of information of a region, texture analysis and synthesis are important components of digital image processing.It is difficult to provide a formal definition of texture although we perceive and recognize texture rather easily. According to Sklansky [152) "A region in …

A 2-2/3 Approximation For The Shortest Superstring Problem, Chris Armen, Clifford Stein

Computer Science Technical Reports

Given a collection of strings S={s_1, ..., s_n} over an alphabet \Sigma, a superstring \alpha of S is a string containing each s_i as a substring; that is, for each i, 1<=i<=n, \alpha contains a block of |s_i| consecutive characters that match s_i exactly. The shortest superstring problem is the problem of finding a superstring \alpha of minimum length. The shortest superstring problem has applications in both data compression and computational biology. In data compression, the problem is a part of a general model of string compression proposed by Gallant, Maier and Storer (JCSS '80). Much of the recent interest in the problem is due to its application to DNA sequence assembly. The problem has been shown to be NP-hard; in fact, it was shown by Blum et al.(JACM '94) to be MAX SNP-hard. The first O(1)-approximation was also due to Blum et al., who gave an algorithm that always returns a superstring no more than 3 times the length of an optimal solution. Several researchers have published results that improve on the approximation ratio; of these, the best previous result is our algorithm ShortString, which achieves a 2 3/4-approximation (WADS '95). We present our new algorithm, G-ShortString, which achieves a ratio of 2 2/3. It generalizes the ShortString algorithm, but the analysis differs substantially from that of ShortString. Our previous work identified classes of strings that have a nested periodic structure, and which must be present in the worst case for our algorithms. We introduced machinery to descibe these strings and proved strong structural properties about them. In this paper we extend this study to strings that exhibit a more relaxed form of the same structure, and we use this understanding to obtain our improved result.

The Professional Evolution Of Wildlife Damage Management, James E. Miller

Wildlife Damage Management Conference

The term -- wildlife damage management, in lieu of animal damage control, vertebrate pest control, or nuisance animal control -- has become the currently recognized term for an area of wildlife management that a growing number of professionals spend a significant part of their time and/or career working in. The acceptance of this terminology is, however, a part of the continuing evolution of the profession and not simply a name change for political correctness. Admittedly, my purpose is not to validate or beg acceptance of this terminology. Rather, what I hope to do is to justify the underlying premise of …

Efficacy Of Shooting Permits For Deer Damage Abatement In Wisconsin, Rick R. Horton, Scott R. Craven

Wildlife Damage Management Conference

The efficacy of out-of-season shooting permits for deer damage abatement in Wisconsin has not been critically evaluated. We used deer damage shooting permits to remove 21 antlerless deer (Odocoileus virginianus) from 7 heavily damaged alfalfa fields to evaluate subsequent impact on crop damage. Volunteer shooters, using permits issued to the landowners, hunted a minimum of 3 nights/week throughout the growth of the third alfalfa crop (Aug. 1 - late Sept.). We calculated the difference between the assessed damage to the second crop (untreated) and the third crop (treated) on treatment and control farms. We found no significant difference …

Wildlife Damage Control In Kansas: Private Operators And Public Agencies, L. Andrew Madison, Philip S. Gipson

Eastern Wildlife Damage Management Conference: 7th (1995)

The private industry in wildlife damage control is expanding into territory predominantly occupied by public agencies in the past. There is a potential for overlap and competition in services provided by the public and private sectors in Kansas. We examined wildlife damage control activity reports from the Cooperative Extension Service (CES), Kansas Department of Wildlife and Parks (IDWP), and private nuisance wildlife control operators (NWCO) to determine the most common species controlled by each and their overlap in services across Kansas. The CES predominantly controlled coyotes (Canis latrans). KDWP primarily controlled beavers (Castor canadensis), deer ( …

A Historical Perspective Of Catfish Production In The Southeast In Relation To Avian Predation, Donald F. Mott, Martin W. Brunson

Wildlife Damage Management Conference

Production of aquaculture species, especially catfish (Ictalurus punctatus) in the Mississippi Delta, is a relatively new and expanding industry. Catfish production represents the largest dollar value of the aquaculture industry, accounting for approximately 50% of the entire industry. Mississippi is responsible for 82% of the total U.S. catfish production. Fish-eating bird populations have capitalized on this new food source. Double-crested cormorants (Phalacrocorax auritus), great blue herons (Ardea herodias), and great egrets (Casmerodius albus) are the primary predators on catfish. Cormorant caused losses in excess of $2 million per year have been reported in …

Relationships Between Wild Turkeys And Raccoons In Central Mississippi, Charles D. Lovell, Darren A. Miller, George A. Hurst, Bruce D. Leopold

Wildlife Damage Management Conference

Reduced trapping and hunting of predators has led to concerns that increased predator densities may affect game species populations. Therefore, we investigated effects of predation on the wild turkey population on Tallahala Wildlife Management Area (TWMA), Mississippi, from 1984-94. We also determined trends in raccoon trapping and hunter harvest in Mississippi. Predation of nests (eggs), nesting hens, and poults caused a population decline on TWMA. Most (88%) nest failures were caused by predation from 1984-94; raccoons were the dominant predator. Declining raccoon hunter harvest from 1980-94 was correlated with declining hunter effort. Trapping license sales and trapping harvest also declined. …