Digital Commons Network^™

The Nebraska Natural Heritage Program: Two Year Progress Report, Mary Clausen, Mike Fritz, Gerry Steinauer

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

Since European settlement, human activities have totally eliminated the natural vegetation from approximately 50 percent of Nebraska’s landscape, and of that remaining most has been heavily impacted. As a result, numerous plants and animals have been extirpated from the state and many others are threatened.

The destruction of Nebraska’s natural diversity resulted in both public and private conservation groups recognizing the need for a centralized and accessible biological database for the state’s rare species and natural community types. Toward this end, the Nebraska Natural Heritage Program (NENHP) was established in August, 1987 through a cooperative effort between The Nature Conservancy …

Back Propagation With Integer Arithmetic, Takayuki Dan Kimura

All Computer Science and Engineering Research

The present work investigates the significance of arithmetic precision in neural network simulation. Noting that a biological brain consists of a large number of cells of low precision, we try to answer the question: With a fixed size of memory and CPU cycles available for simulation, does a larger sized net with less precision perform better than smaller sized one with higher precision? We evaluate the merits and demerits of using low precision integer arithmetic in simulating backpropagation networks. Two identical backpropagation simulators, ibp and fbp, were constructed on Mac II, ibp with 16 bits integer representations of network parameters …

A Laboratory Characterization Of Pulp And Paper Mill Solid Wastes For Potential Use As Hydraulic Barrier Material In Landfill Covers, Carleton Van Maltby

Masters Theses

Fifteen sludges from wastewater treatment systems of pulp and paper mills that encompass major production categories, and eight fly ashes from mill boilers incinerating wood waste, coal, or their combination were characterized for their potential suitability as hydraulic barrier material. Hydraulic conductivity was observed to range over four orders of magnitude for the materials tested.

Anthropometric Parameters In Public School Students And Seventh-Day Adventist Vegetarian And Meat-Eating Students, Joan Sabaté-Casellas

Loma Linda University Electronic Theses, Dissertations & Projects

Concerns have been expressed for the ability of some vegetarian diets to support normal growth of children. Animal protein or meat intake showed a positive relationship to attained height in children from developing countries. In this study, the relationship between meat intake/vegetarian status and physical growth was investigated in children living in California.

Height and weight were collected on 2,272 Caucasian children aged 6-18 years attending Seventh-day Adventist (SDA) or public schools who participated in a two year longitudinal study. Age-, sex-, and school-specific mean heights and weights were at or above the national reference values. Sex-specific, age-adjusted regression analysis …

Temporal And Spatial Patterns Of Abundance Of Age 0 Threadfin Shad (Dorosoma Petenense) In Overton Arm, Lake Mead, William Lee Pelle

Publications (WR)

Temporal and spatial patterns of age 0 threadfin shad (Dorosoma petenense) abundance and growth, in the Overton Arm of Lake Mead, were examined to evaluate the effects of resource availability on the young fish. This was part of a larger, game fishery enhancement study (Lake Mead Fertilization Project), designed to assess feasability of increasing survivorship of larval/juvenile shad by boosting phosphate levels, thereby increasing algal and zooplankton biomass, during the shad spawning period. Shad are the primary forage base for the striped bass (Morone saxatilis) and black bass (Macropterus salmoides) fisheries. Weekly samples were …

Water Resources Review - June 1989, Annis Water Resources Institute

AWRI Reviews

No abstract provided.

Investigation Of Major Mutagenic Substances In Airborne Particulate Matter : Biologically-Driven Analysis Of Fractions And Analysis Of Polycyclic Aromatic Hydrocarbons (Pahs) Nitro-Pahs And Other Classes Of Compounds, Jung-Hen Lwo

Theses

A modified fractionation scheme involving acid-base partitioning and silica gel column chromatography has been used as the first step in the bioassay-directed search for significant levels of mutagenic compounds in extracts of inhalable (IP10) ambient air particulates. The biologically "hot" fractions were separated and analyzed chemically or subfractionated to isolate and concentrate "hot" subfractions which were then chemically analyzed by GC/MS FTIR, and HPLC equipped with UV, Fluorescence and Photodiode Array UV detectors.

The Ames assay of mutagenicity has involved the unactivated TA98 strain of Salmonella and enzyme-activated (TA98+S9) assays. In addition, some assays have been performed in this present …

Determination Of Trace Amounts Of Lead, Cadium And Zinc In Vegetables Using Differential Pulse Polarography, Elizabeth Franca-Romitti

Theses

Toxic metals are present in foods to greater or lesser extention as contaminants, as a result of increasing industrialization, and associated pollution of the biosphere. Lead and cadmium are well known toxic metals which accumulate into the body causing harmful effects at low concentration levels especially in children. Zinc, on the other hand, is an essential micronutrient, but larger levels in foods can be considered toxic.

Twenty eight brands of vegetables including canned, glass packed, frozen and fresh vegetables were analyzed for Pb, Cd, and Zn, in tomatoes, carrots, mushrooms and asparagus. The technique used was Differential Pulse Polarography (DPP) …

Microbial Competition In The Biodegradation Of Phenol, Mary Ellen Frank

Theses

Three phenol degraders were isolated from the mixed liquor of the Livingston, NJ municipal treatment plant. Shaker flask experiments using one of the degraders (a Pseudomonas sp.) resulted in the determination of its kinetic rate constants. The second phenol degrader (a Xanthamonas) lost its phenol degrading ability while being stored, and its kinetic rate constants could not be determined. The third phenol degrader (a Pseudomonas cepacia) formed flocs which interfered with the spectrophotometric determination of biomass and therefore its kinetic rate constants also could not be determined.

Mixed culture experiments were carried out using a the Pseudomonas sp. and a …

Study Of An Analytical Method For Benzo(A)Pyrene Metabolites In Human Urine, Zheng Ouyang

Theses

A method developed by Becher and Bjorseth for analysis of PAH metabolites in urine was employed to investigate human exposure to benzo(a)pyrene (BaP) - an ubiquitous environmental carcinogen. Preliminary results are presented showing the relationship between exposure to BaP and urinary elimination. Although the correlation between the two variables is not statistically significant, there appears to be a positive association with selected exposure varibles such as smoking. The identification of an association may establish urinary BaP as a marker of exposure.

However, detailed study of the analytical procedure indicated that recoveries with this method were as low as 3-8% for …

Determination Of Benzo(A)Pyrene Metabolites In The Bile Of Winter Flounder From The New York Bight, Xingmin Liu

Theses

A method for detecting the concentration of BaP Metabolites in fish tissues has been developed. The analytical procedure includes extraction of PAH and BaP Metabolites from fish bile, liver extract and muscle extract; reduction of metabolites to BaP using hydriodic acid; and subsequent analysis of the BaP by thin layer chromatography with fluorescence detection. The method is applied to tissues from fish collected from polluted as well as clean reference waters and experimental tanks with dilutions of treated industrial wastewater. Experimental results on one kind of bottom-dwelling fish, winter flounder, which comes from the Hudson-Raritan Estuary, NY, where the water …

Characterization Of Activated Sludge Immobilized In Calcium Alginate Gel With Respect To Biodegradation Of 2-Chlorophenol And Benzene, Manjari Singh

Theses

Activated sludges acclimated with phenol and 2-chlorophenol in one case, and a mixture of benzene, toluene, and o, in and p-xylene in another case, were characterized for biodegradation of 2-chlorophenol and benzene, respectively. Activated sludge was obtained from the Parsippany-Troy Hills Water Pollution Control Plant (NJ).

For both cases colonies were isolated before acclimation, after acclimation, and at the end of biodegradation studies. Since the unacclimated group was the same in both cases, there were a total of five different groups for which characterization was carried out.

For all the five groups together, a total of 54 isolates were obtained …

Thermal Desorption Of Hazardous And Toxic Organic Compounds From Soil Matrices, Sarah Calandra

Theses

The purpose of this research project was to determine feasiblity to remove organic contaminants from various soil matrices by thermal desorption and gas purge. The volatization and gas purge of organic contaminants from the soil increases under the influence of heat and inert gas.

The work was done in two parts. First, under isothermal conditions, organic compounds were injected as a plug unto columns that contained real or simulated soil matrices. These columns were continuously purged with a carrier gas (nitrogen) and a gas chromatogragh equipped with Flame Ionization Detector but no added column other than the soil was used …

Investigation Of Benzo(A)Pyrene In Outdoor Air, Indoor Air And Personal Inhalation Air, Hsiu-Wen Chen

Theses

The assessment of human exposure to an environmental contaminant requires the measurement of the concentrations levels present in each pathway of possible contact.

This was an investigation of human exposure to an environmental pollutant, benzo(a)pyrene, in outdoor air, indoor air and personal inhalation air samples. The analytical procedure involved extraction by ultrasonic and separation by thin layer chromatography, and detection by fluorescence. The resulting data was used to develop a profile of indoor and outdoor human exposure to B(a)P during the year.

Thermal Decomposition Of Dichloromethane In Hydrogen/Oxygen/Argon Mixtures And In Pure Oxygen, Wen-Pin Ho

Theses

The thermal decomposition of Dichloromethane in hydrogen/oxygen mixtures and argon bath gas was carried out at 1 atmosphere total presure in tubular flow reactors of varied surface to volume (S/V) ratio. The thermal degradation of dichloromethane was analyzed systematically over temperature ranges from 610 to 820°C, with average residence times in range of 0.1 to 2.0 seconds. Five reaction sets in three different size flow reactors were studied.

It was found that the complete decay ( 99% ) of the dichloromethane at 1 second residence time occurs at about 810°C for all the reactants ratio sets. The major products for …

Thermal Desorption Of Hazardous And Toxic Organic Compounds, Manuel S. Nolau

Theses

The purpose of this thesis is to study the thermal desorption behavior of toxic organic compounds, specifically o-xylene, p-xylene, ethyl benzene, p-chlorotoluene, and anthracene, from soil with respect to temperature and time, and to develop a mathematical model that will describe this desorption behavior. The model will allow prediction of the concentration of an organic contaminant in commercial soil desorption system over time given a known set of parameters of the specific chemical as well as flow rate and temperature. For this purpose, two sets of experiments were done: These are identified as 1. Thermal desorption and 2. plug flow …

Synthesis Of Site Specific 1, N^2-Ethenodeoxyguanosine In A Small Oligonucleotide, Kathryn A. Carolin

Wayne State University Theses

Malondiadehyde (MDA) is a known carcinogen and mutagen produced by lipid peroxidation and prostaglandin synthesis in vivo. MDA is unique from structurally related compounds, methyl glyoxal and acrolein, because it produces frameshift mutations whereas the latter compounds induce base-pair substitutions. MDA forms several adducts with deoxyguanosine but it is not certain which one causes the frameshift mutations. Ideally, a single adduct on a replicating genome could simulate the in vivo process by which MDA mutagenesis would occur. This technique is known as site-specific mutagenesis. The approach of choice for site-specific mutagenesis experiment is the gapped heteroduplex method which requires the …

Origins Of The Quantum Efficiency Duality In The Primary Photochemical Event Of Bacteriorhodopsin, Robert R. Birge, Leonore A. Findsen, Albert F. Lawrence, Mark Masthay, Chian-Fan Zhang

Chemistry Faculty Publications

Experimental and theoretical evidence is presented which suggests that two distinct forms of light-adapted bacteriorhodopsin may exist. We propose that these two forms have characteristic photocycles with significantly different primary quantum yields. INDO-PSDCI molecular orbital procedures and semiempirical molecular dynamics simulations predict that one ground state geometry of bR undergoes photochemistry with a primary quantum yield, Φ1, of ~ 0.27, and that a second ground state geometry, with a slightly displaced counterion, yields Φ1 ~ 0.74. This theoretical model is supported by the observation that literature measurements of Φ1 tend to fall into one of two categories- those that observe …

The Prairie Naturalist Volume 21, No.2 June 1989

The Prairie Naturalist

THE MISSISSIPPI KITE IN THE ENVIRONMENTAL HISTORY OF THE SOUTHERN GREAT PLAINS ▪ E. G. Bolen and D. L. Flores

TAPE-RECORDED CHICK CALLS TO LOCATE GRAY PARTRIDGE NESTS ▪ J. P. Carroll

BORROW DISTRIBUTION OF THE THIRTEEN-LINED GROUND SQUIRREL IN GRAZED MIXED-GRASS PRAIRIE: EFFECT OF ARTIFICIAL HABITAT STRUCTURE ▪ D. W. Kaufman and G. A. Kaufman

PIPING PLOVERS NESTING AT NELSON RESERVOIR, MONTANA ▪ D. W. Prellwitz, T. A. Prellwitz, K. L. Stutzman, and J. W. Stutzman

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA - 1988 ▪ R. N. Randall

CHANGING HABITATS IN THE PLATTE RIVER VALLEY OF NEBRASKA ▪ J. …

The Benefits Of Weaning Cattle In The Kimberley, David Pratchett, Stuart Young

Animal production and livestock research reports

The Kimberley region was populated with Shorthorn cattle from Queensland and New Sonth Wales in the 1880's. The descendants of these cattle known as Kimberley Shorthorn are still the predominant breed in the region. The relatively poor performance of these cattle under the harsh Kimberley conditions and the fact that changing the genotype can improve productivity was recently published (Pratchett D. WADA Journal No. 4 1988)

While the adoption of Bos indicus breeds is the correct move, improved husbandry can also increase the productivity of the Kimberley Shorthorn cow. The majority of cattle in the Kimberley are not weaned. Sometimes …

Total Maximum Daily Loads And Waste Load Allocations For Las Vegas Bay: Rationale And Calulations, State Of Nevada: Division Of Environmental Protection

Publications (WR)

In September 1987 the Nevada Division of Environmental Protection revised Water Quality Standards for Las Vegas Wash (LVW) and Lake Mead. Standards were set for chlorophyll-a and unionized ammonia in Las Vegas Bay (LVB) (NDEP 1987). The 1986 and 1987 LVB data showed non-achievement of both the chlorophyll-a and unionized ammonia standard which triggered an analysis of total phosphorus and total ammonia Total Maximum Daily Loads and Waste Load Allocations which are presented in this report. This report is separated into three sections: 1. 1987 Las Vegas Bay Water Quality Conditions and Seasonal Periodicity. 2. Concentration Estimates at Northshore Road …

Root Exploitation Of Fertile Soil Microsites, Robert B. Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Root exploitation of enriched soil microsites was examined for the tussock grasses Agropyron desertorum and Agropyron spicatum and the shrub Artemisia tridentata. Two mechanisms of exploitation of the microsites were examined: root proliferation and changes in nutrient uptake capacity. One day after nutrient solution was applied to small soil patches, the mean relative growth rate of Agropyron desertorum roots in enriched patches was two to four times greater than for roots of the same plants in soil patches treated with distilled water. This rapid and striking root proliferation occurred in response to N-P-K enrichment as well as to P or …

Modeling Forest Dynamics Based On Stand Level Resource Allocation, Geoffrey Candler Poole

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An ecologically based model of forest succession is presented. In the model, trees compete for a share of limited growth resources available from their environment. Competition is reflected by each tree's effect on the resource pool and is not explicitly modeled. Model parameters were fit to field data from subalpine forests of the Rocky Mountains. A technique for estimating model parameters from understory-tolerance rankings and silvical characteristics of each species is also presented. The model's output was consistent with our current understanding of forest dynamics. Emergent properties of the model also mimicked natural processes such as self-thinning, release, and maximum …

Using Computer Imaging To Assess Visual Impacts Of Forest Insect And Disease Pests, Daniel Rabin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forest insect and disease pests alter the appearance of trees, thereby impacting visual resources. Because of the complexity of most forest landscapes, the degree of visual impact of pest-infested forest stands is difficult to quantify.

This paper describes a method of measuring visual impacts of pest-infested forest stands. Photographs of healthy Ponderosa pine trees were entered into a computer video-image-processing system. Using this system, images of trees were altered to simulate different degrees of infestation by limb rust, a forest pathogen.

The altered and unaltered images were shown to groups of observers who rated the scenes in terms of "scenic …

Management, Foraging Behavior, Diet Composition And Forage Quality Of Free-Ranging But Herded Camels In Ceeldheer District, Central Somalia, Ahmed A. Elmi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In Somalia, camel (Camelus dromedarius) survivability and milk production has been higher than for other domestic livestock and contributes substantially to the subsistence of Somali pastoralists. The objective of this research was to study management, foraging behavior and nutrition of camels in their natural habitat to determine how production continues under seasonal nutritional stress.

Management systems of Ceeldheer pastoralists are based on available natural pasture and water. The natural rotation grazing system maintained an ecological equilibrium in the District.

Pastoralists manipulate their herds to suit existing environmental conditions, family needs and labor availability for herding. In herd management, …

A Study Of Denitrosation Of N-Nitroso Compounds By Irradiation With Long-Wavelength Uv Light, Zhenyu J. Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

N-Nitrosamines and N-nitrosamides have been reported to be mutagenic. N-Nitrosamides are direct mutagens that need no activation to be mutagenic, whereas N-nitrosamines need to be enzymatically activated to exert their mutagenicity. Oxidative demethylation of nitrosamines is a commonly accepted activation mechanism. Another pathway of nitroso compounds, denitrosation, has recently been proposed. The mechanism of denitrosation, however, is still unknown.

The purpose of this study was to use a photo -reaction model to explore the possible denitrosation mechanism of N-nitroso compounds. An N-nitrosamine, N-nitrosomorpholi ne (NMOR), and an N-nitrosamide, N-methyl-N'-nitrosoguanidine (MMNG), were irradiated with long-wavelength UV light in the presence of …

Santa Clara Magazine, Volume 31 Number 3, Spring 1989, Santa Clara University

Santa Clara Magazine

10 - VISION Santa Clara's new president talks about his priorities for the University in the decade ahead.

15 - FAMILY IN CRISIS Is the Silicon Valley family an endangered species?

18 - DUBLIN: CITY OF 1,000 YEARS Today it is a bustling European capital. But progress has come at a price.

22 - GEORGE AND THE SILVER FOX A behind-the-scenes look at President and Mrs. Bush.

27 - WHO SHALL CARE .. . AND HOW? By 2020 every fourth American may be 65 or over.

Habitat Use And Diet Analysis Of Breeding Common Barn Owls In Western Nebraska, Joseph A. Gubanyi M.S.

School of Natural Resources: Dissertations, Theses, and Student Research

I studied barn owl (Tyto alba) breeding biology in western Nebraska 1984-1986. I had greatest success capturing males (56% success) at night using trap doors at nest sites and females (91 % success) using hoop nets at nest sites during the day. Barn owls removed 16 of 23 tail-mounted radios. Eight birds were radio-tracked for 7-14.5 hours. The mean foraging range was 198 ha (32- 299 ha, n = 8) with < 1 % overlap among birds from adjacent nest sites. Field-tested telemetry error was high (mean displacements of radio-locations for 2 birds were 208 and 241 m). I found no relationship between percent cover in foraging habitat and reproductive success. I identified 10,140 prey items from 15 nest sites and found both annual and seasonal variation in barn owl diets. Microtus ochrogaster occurred most frequently (32.7%) and increased in the diet from 17.6 to 27.2 to 43.5% 1984-1986. M. ochrogaster and Perognathus hispidus annual frequencies were …

Recent Improvements Of Water Quality And Biological Indicators In Hillsborough Bay, The Northeastern Section Of Tampa Bay, Florida, J.O. R. Johansson

Reports

The City of Tampa was implicated as a major point source polluter of Hillsborough Bay based on its release since 1951 of primary treated wastewater effluent into the bay. To alleviate nutrient loads into Hillsborough Bay, the City of Tampa upgraded its Hooker's Point facility to advanced wastewater treatment (AWT) with a 60 MGD capacity. The transformation from primary treatment to advanced was successive.

The State Of Tampa Bay- 1988, Tampa Bay Regional Planning Council (Tbrpc), Agency On Bay Management

Reports

Council's Agency on Bay Management has continued to lead and support major Bay related activities through legislation, development review, intergovernmental coordination, impact assessment and public education in 1988. Management and research efforts expand for the Bay as awareness grows of its significance. The State of the Bay - 1988 document represents the compilation of regional activities and these expanding effort to promote the Tampa Bay estuary.