Digital Commons Network^™

Phosphorus Removal From Ebpr Sludge Dewatering Liquors Using Lanthanum Chloride, Aluminum Sulfate And Ferric Chloride, Michael Strileski

UNLV Theses, Dissertations, Professional Papers, and Capstones

In wastewater treatment, enhanced biological phosphorus removal (EBPR) is becoming an increasingly popular alternative to chemical precipitation (CP) because of its lower costs and reduced sludge production. However, downstream solids handling processes such as digestion, sludge storage and dewatering promote an undesirable release (i.e. secondary release) of polyphosphate that was stored within EBPR sludge. Released phosphate is recycled to the head of the plant with the liquors of sludge dewatering processes. The concentration of phosphate in recycle streams from EBPR systems can be one to two orders of magnitude higher than the influent phosphorus concentration entering the EBPR system. Plants …

Long-Term Bald Eagle Monitoring: Assessing Emerging Risks To The Great Lakes Ecosystem By Evaluating Impacts To Tertiary Predators, Latice Fuentes

All Dissertations

Data from the Michigan Bald Eagle Biomonitoring Project (MBEBP) was used to provide ecological evaluations amidst concerns of emerging contaminants and environmental change. Samples and measurements were collected throughout the state of Michigan from 1998-2012. Nestling breast feathers and biometric measurements were used in analytical and statistical analyses which provided a broad assessment of the Great Lakes ecosystem and its resident bald eagles. Bald eagle nestling feathers were taken from Michigan breeding areas, and used to evaluate spatial and temporal trends of mercury (Hg). Overall, remediation has positively affected the Great Lakes region. However, Michigan's Upper Peninsula and Lake Superior …

Conservation Genetics And Population Status Of The Flame Chub, Hemitremia Flammea, Kathlina Frances Alford

Masters Theses and Doctoral Dissertations

The southeastern United States has a rich geologic history that contributed to the evolution of an extremely diverse aquatic fauna throughout the region. The Flame Chub, Hemitremia flammea, is a brightly colored, spring endemic minnow species native to the Cumberland, Tennessee, and Coosa river drainages. In this study, the cytochrome-b gene region was analyzed for 230 individuals from 29 populations across the three drainages. Results from maximum parsimony and Bayesian analyses recovered shallow divergence between the 31 haplotypes. AMOVA analyses indicated that most gene tic variation distributed within and between populations, not between drainages. Based on these results, this species …

Paleoecology Of Late Pleistocene Megaherbivores: Stable Isotope Reconstruction Of Environment, Climate, And Response, Aubrey Mae Bonde

UNLV Theses, Dissertations, Professional Papers, and Capstones

Late Pleistocene megaherbivore communities of the Pacific and Mountain West states of California and Nevada are under-analyzed in regard to ecological function (diet, mobility, niche partitioning, and range of ecological tolerance). Stable isotope analysis is a powerful tool that is known to recover primary paleodiet and paleoenvironmental information from biogenic materials, such as enamel and dentin. This dissertation explores the use of carbon and oxygen stable isotopes in Late Pleistocene (40-10 Ka) megaherbivore teeth to gain a better understanding of inter- and intra-specific behavior and reconstruct Late Pleistocene ecosystems of California and Nevada. Radiocarbon dates exist for most of the …

Investigation Of Storage-Phosphor Autoradiography For The Rapid Quantitative Screening Of Air Filters For Emergency Response Purposes, Athena Marie Gallardo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Past nuclear accidents, such as Chernobyl, resulted in a large release of radionuclides into the atmosphere. Radiological assessment of the vicinity of the site of the incident is vital to assess the exposure levels and dose received by the population and workers. Therefore, it is critical to thoroughly understand the situation and risks associated with a particular event in a timely manner in order to properly manage the event. Current atmospheric radiological assessments of alpha emitting radioisotopes include acquiring large quantities of air samples, chemical separation of radionuclides, sample mounting, counting through alpha spectrometry, and analysis of the data. The …

Understanding Basin Specific Life History Characteristics Of Lake Mead Quagga Mussels (Dreissena Bugensis) And A Potential Treatment Using Uv Radiation In Laboratory Studies, Melissa Thaw

UNLV Theses, Dissertations, Professional Papers, and Capstones

The quagga mussel (Dreissena bugensis) is an aquatic invasive species that is spreading throughout Lake Mead and other western waterways. Unlike their native waters in Eurasia, Lake Mead exhibits year round warm temperatures, high calcium levels and a lack of natural predators, all of which are very favorable conditions for their growth and spread. Dreissena bugensis reproduce and colonize hard surfaces rapidly, where they filter large amounts of water. They disrupt the aquatic food chain and interfere with infrastructure that is exposed to lake water. There is an urgent need to understand Dreissena bugensis life history characteristics within this new …

Evaluation Of Broiler Litter Heat Production During Windrowing & Nitrogen Based Gas Emission Mitigation Using Biofilter, Min Lei

Graduate Theses and Dissertations

Ammonia emission from animal feeding operations (AFOs) has negative effects on environment and animals' health. Thus measuring and mitigating ammonia emission from AFOs is important for environmental protection. In chapter I, different ammonia measurements were discussed and a mitigation technology- biofilter was represented.

In-house windrowing of built-up litter has been used by broiler producers to reduce pathogen loads and rejuvenate litter for the next flock. When litter is piled up for an extended period during downtime, heat generated by the litter pile can become a substantial heat source due to the metabolism of microorganisms. In chapter II, heat production rates …

Evaluation Of Water Sanitation Options For Poultry Production, Pramir Maharjan

Graduate Theses and Dissertations

An evaluation of poultry farm water supplies was conducted to determine the value and impact of water system sanitation practices in commercial broiler houses on microbial levels. Water line cleaning between flocks using concentrated disinfectant solution before placing chicks reduced biofilms retained in the lines to a safe level. Occasional microbial surges were noticed during different points of flock grow-out period even when daily water sanitation was present indicating water is highly susceptible to microbial contamination. However, the daily water sanitation practice controlled the occasional microbial surges in water from sustaining and kept drinking water to a microbiologically acceptable level. …

Modeling Habitat Use Of A Fringe Greater Sage-Grouse Population At Multiple Spatial Scales, Anya Cheyenne Burnett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) are a prominent bird species of sagebrush-dominated landscapes across the western United States. Over the past 15 years, sage-grouse have gained international attention due to decreasing population trends despite management efforts. In 2010 the U.S. Fish and Wildlife Service designated this species as warranted for listing under the Endangered Species Act, but the listing was precluded by other species at higher conservation risk. Habitat loss, degradation, and fragmentation have been implicated as primary sources of declines in sage-grouse distribution and abundance. The Bald Hills population in southwestern Utah occupies an area with …

Natural Area Stewardship Volunteers: Motivations, Attitudes, Behaviors, Corinne Handelman

Dissertations and Theses

To better understand the value of those who engage in environmental stewardship of natural areas, we studied volunteer steward's motivation to participate, their sustainable behaviors and attitudes toward stewardship-related constructs. Specifically, we designed and conducted a survey of volunteers who work as stewards in urban natural areas in Portland, Oregon. We hypothesize that as volunteer frequency increases: participants will be more motivated to participate for environmental reasons, volunteers will be more likely to feel a strong connection to the stewardship site, participants will be more likely to engage in public pro-environmental behaviors, and their level of environmental literacy will increase. …

Social-Ecological Dynamics Of Coral Reef Resource Use And Management, Sarah J. Freed

Dissertations and Theses

This dissertation investigates social and ecological factors that facilitate effective management of coral reefs as social-ecological systems. Meta-analytical and field-based methods were employed to examine current management challenges and identify strategies that improve management effectiveness and coral reef health. A meta-analysis was used to evaluate biological indicators of reef health in relation to the types of fishing regulations in place (no-take areas, gear restriction areas, and periodic closures) and the actor groups (community-based, co-management, state, private) involved in management efforts for coral reef fisheries throughout the world. Other than enhancement of fish biomass within no-take areas that was significantly greater …

Chinese Vessel Pollution Prevention In The Era Of The Green Economy, Zhilin Zheng

World Maritime University Dissertations

No abstract provided.

A Lover And A Fighter: The Genome Sequence Of An Entomopathogenic Nematode Heterorhabditis Bacteriophora, Xiaodong Bai, Byron J. Adams, Todd A. Ciche, Sandra Clifton, Randy Gaugler, Kwi-Suk Kim, Parwinder Grewal

School of Earth, Environmental, & Marine Sciences Faculty Publications

Heterorhabditis bacteriophora are entomopathogenic nematodes that have evolved a mutualism with Photorhabdus luminescens bacteria to function as highly virulent insect pathogens. The nematode provides a safe harbor for intestinal symbionts in soil and delivers the symbiotic bacteria into the insect blood. The symbiont provides virulence and toxins, metabolites essential for nematode reproduction, and antibiotic preservation of the insect cadaver. Approximately half of the 21,250 putative protein coding genes identified in the 77 Mbp high quality draft H. bacteriophora genome sequence were novel proteins of unknown function lacking homologs in Caenorhabditis elegans or any other sequenced organisms. Similarly, 317 of the …

Selecting Surrogate Endpoints For Estimating Pesticide Effects On Avian Reproductive Success, Richard S. Bennett, Matthew A. Etterson

United States Environmental Protection Agency: Publications

A Markov chain nest productivity model (MCnest) has been developed for projecting the effects of a specific pesticide‐use scenario on the annual reproductive success of avian species of concern. A critical element in MCnest is the use of surrogate endpoints, defined as measured endpoints from avian toxicity tests that represent specific types of effects possible in field populations at specific phases of a nesting attempt. In this article, we discuss the attributes of surrogate endpoints and provide guidance for selecting surrogates from existing avian laboratory tests as well as other possible sources.We also discuss some of the assumptions and uncertainties …

The Water Footprint Of Biofuel Produced From Forest Wood Residue Via A Mixed Alcohol Gasification Process, Yi-Wen Chiu, May Wu

Natural Resources Management and Environmental Sciences

Forest residue has been proposed as a feasible candidate for cellulosic biofuels. However, the number of studies assessing its water use remains limited. This work aims to analyze the impacts of forest-based biofuel on water resources and quality by using a water footprint approach. A method established here is tailored to the production system, which includes softwood, hardwood, and short-rotation woody crops. The method is then applied to selected areas in the southeastern region of the United States to quantify the county-level water footprint of the biofuel produced via a mixed alcohol gasification process, under several logistic systems, and at …

Individual And Population Level Resource Selection Patterns Of Mountain Lions Preying On Mule Deer Along An Urban-Wildland Gradient, John F. Benson, Jeff A. Sikich, Seth P. D. Riley

School of Natural Resources: Faculty Publications

Understanding population and individual-level behavioral responses of large carnivores to human disturbance is important for conserving top predators in fragmented landscapes. However, previous research has not investigated resource selection at predation sites of mountain lions in highly urbanized areas. We quantified selection of natural and anthropogenic landscape features by mountain lions at sites where they consumed their primary prey, mule deer (Odocoileus hemionus), in and adjacent to urban, suburban, and rural areas in greater Los Angeles. We documented intersexual and individual-level variation in the environmental conditions present at mule deer feeding sites relative to their availability across home …

The Impact Of Nitrogen Contamination And River Modification On A Mississippi River Floodplain Lake, Indu Karthic, Richard B. Brugam Ph.D., William A. Retzlaff, Kevin Johnson

SIUE Faculty Research, Scholarship, and Creative Activity

Anthropogenic nitrogen contamination has increased in ecosystems around the world (frequently termed the “nitrogen cascade”). Coke production for steel manufacturing is often overlooked as a source of nitrogen to natural ecosystems. We examined sediment cores from a Horseshoe Lake, a floodplain lake located just East of St. Louis Missouri (USA) to test whether a coking plant effluent could be traced using stable isotopes of nitrogen and diatom microfossils. The distribution of δ¹⁵N values in surface sediment samples from the lake shows the highest values near the coking plant effluent. Analysis stable isotopes of nitrogen from sediment cores using …

A Protected Area Influences Genotype-Specific Survival And The Structure Of A Canis Hybrid Zone, John F. Benson, Brent R. Patterson, Peter J. Mahoney

School of Natural Resources: Faculty Publications

It is widely recognized that protected areas can strongly influence ecological systems and that hybridization is an important conservation issue. However, previous studies have not explicitly considered the influence of protected areas on hybridization dynamics. Eastern wolves are a species of special concern and their distribution is largely restricted to a protected population in Algonquin Provincial Park (APP), Ontario, Canada, where they are the numerically dominant canid. We studied intrinsic and extrinsic factors influencing survival and cause-specific mortality of hybrid and parental canids in the three-species hybrid zone between eastern wolves, eastern coyotes, and gray wolves in and adjacent to …

James’S Rule And Causes And Consequences Of A Latitudinal Cline In The Demography Of John’S Snapper (Lutjanus Johnii) In Coastal Waters Of Australia, Mike Cappo, Ross J. Marriott, Stephen J. Newman

Fisheries Research Articles

Demographic parameters were derived from sectioned otoliths of John’s Snapper (Lutjanus johnii) from 4 regions across 9° of latitude and 23° of longitude in northern Australia. Latitudinal variation in size and growth rates of this species greatly exceeded longitudinal variation. Populations of John’s Snapper farthest from the equator had the largest body sizes, in line with James’s rule, and the fastest growth rates, contrary to the temperature size rule for ectotherms. A maximum age of 28.6 years, nearly 3 times previous estimates, was recorded and the largest individual was 990 mm in fork length. Females grew to a larger mean …

Reviewing Models Of Land Availability And Dynamics For Biofuel Crops In The United States And The European Union, Ruopu Li, Nicola Di Virgilio, Qingfeng Guan, Song Feng, Goetz M. Richter

School of Natural Resources: Faculty Publications

The biofuel-related land use in the USA and the EU has significantly expanded during the last decade; models have been used to estimate land availability and demand in these regions. This paper provides an overview of different land-use modeling practices applicable to first- and second-generation biofuels. We review the importance of different land categories for biofuels, modeling approaches (top-down/bottom-up) and their integration, data availability for calibration and validation, model scale, and uncertainty. Possible future changes of biofuel land use and research gaps and limitations are synthesized. Key issues are the lack of data for independent validation and the need for …

Dominant Inheritance Of Field-Evolved Resistance To Bt Corn In Busseola Fusca, Pascal Campagne, Marlene Kruger, Rémy Pasquet, Bruno Le Ru, Johnnie Van Den Berg

All Peer-Reviewed Publications

Transgenic crops expressing Bacillus thuringiensis (Bt) toxins have been adopted worldwide, notably in developing countries. In spite of their success in controlling target pests while allowing a substantial reduction of insecticide use, the sustainable control of these pest populations is threatened by the evolution of resistance. The implementation of the "high dose/refuge" strategy for managing insect resistance in transgenic crops aims at delaying the evolution of resistance to Bt crops in pest populations by promoting survival of susceptible insects. However, a crucial condition for the "high dose/refuge" strategy to be efficient is that the inheritance of resistance should be functionally …

Seasonal Fires, Bison Grazing, And The Tallgrass Prairie Forb Arnoglossum Plantagineum Raf., Stephen L. Winter, Karen R. Hickman, Carla L. Goad, Samuel D. Fuhlendorf, Mark S. Gregory

School of Natural Resources: Faculty Publications

Fire and grazing can interact to affect the structure and composition of vegetation communities in a manner that may differ from the effects of fire or grazing that occurs in isolation of the other. In order to better understand the effects of a fire-grazing interaction at the level of an individual plant species, we studied the response of a perennial tallgrass prairie forb, Arnoglossum plantagineum Raf., to the interaction of spring and summer fires with grazing by bison (Bison bison L.). During one field season (2006), we collected data in areas that had been treated with summer fires while …

A Prototype Decision Support Tool For Ballast Water Risk Management Using A Combination Of Hydrodynamic Models And Agent-Based Modelling, Fleming T. Hansen, Jesper H. Andersen, Michael Potthof, Thomas Uhrenholdt, Hong D. Vo, Olof Lindén

NSBWO

We report the development of a prototype Decision Support Tool (DST) for modelling the risks of spreading of non-indegenous invasive species via ballast water. The DST constitutes of two types of models: A 3D hydrodynamical model calculates the currents in the North Sea and Danish Straits, and an agent-based model estimates the dispersal of selected model organisms with the prevailing currents calculated by the 3D hydrodynamical model. The analysis is concluded by a post processing activity, where scenarios of dispersal are combined into an interim estimate of connectivity within the study area. The latter can be used as a tool …

Climate Change And Plant Demography In The Sagebrush Steppe, Aldo Compagnoni

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Minor Fitness Benefits For Edge Avoidance In Nesting Grassland Birds In The Northeastern United States, David G. Perkins, Noah G. Perlut, Allan M. Strong

Environmental Studies Faculty Publications

Grassland birds are often affected negatively by habitat fragmentation. Outcomes include greater nest predation and brood parasitism, decreased colonization rates of small, isolated patches, and greater nest density in remnant core habitats. These effects have been well documented in the Midwest, but little is known about fragmentation and edge effects on grassland birds in the fragmented agricultural fields within the forested landscapes of the northeastern United States. From 2002 to 2010, we assessed how edges and edge types affected nest-site location and daily nest survival (DNS) of Savannah Sparrows (Passerculus sandwichensis) and Bobolinks (Dolichonyx oryzivorus) breeding …

Policy On Restocking And Stock Enhancement In Western Australia, Department Of Fisheries Western Australia.

Fisheries Management Papers

The practice of releasing hatchery-reared fish into existing populations to augment fishing (stock enhancement) or restore depleted spawning biomass (restocking) has occurred around the world for decades with varying degrees of success. The underpinning concept is to produce and release fish into wild populations to increase their abundance, catch rates and/or fishery yields

If restocking and stock enhancement activities are to be successful, they should have clear objectives and be well planned and targeted at situations where there is a reasonable expectation of having a beneficial effect.

Will Hubbard Brook Soils Be A Source Or Sink Of Carbon In A Changing Climate?, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.

Water Current, Volume 45, No. 3, Summer 2013

Water Current Newsletter

Ray Joins Nebraska Water Center as Director

UNL "Raising Our H20 IQ" at Husker Harvest Days

October Water Symposium and Water Conference At Lincoln's Cornhusker Hotel

From the Director: Chittaranjan Ray: A Journey from the University of Hawaii to the University of Nebraska

Irrigation Water Management: Water Optimizer, Crop Residue Management, Deficit Irrigation and Soil Water Management Tools

Drought and Groundwater Supplies

Select Groundwater Level Change Report

Modifications, Elevated Levels of Nutrients and Pesticides Degrade

The Kearney Area Chamber of Commerce

Water for Food Speaker: 'Time is Running Out; Time for Action'

WRAP Meets in Early May

Annual Water and …

Brief 8: International Fisheries Governance That Works: The Case For A Global Fisheries Organization, J. Samuel Barkin, Elizabeth R. Desombre

Governance and Sustainability Issue Brief Series

International fisheries are being overexploited, and the current institutional structure in place to manage them is not working effectively. Presently, two sets of intergovernmental institutions oversee global fishing. The first comprises roughly three dozen regional fisheries management organizations (RFMOs), approximately 19 of which are charged with regulating fishing in the areas they oversee. The second set consists of global organizations that touch on but do not directly regulate fisheries issues, such as the United Nations Food and Agriculture Organization (FAO), the World Trade Organization (WTO), the World Bank, and the International Maritime Organization (IMO). This management patchwork is inadequate to …

Using Economic Instruments To Develop Effective Management Of Invasive Species: Insights From A Bioeconomic Model, Shana M. Mcdermott, Rebecca E. Irwin, Brad W. Taylor

Dartmouth Scholarship

Economic growth is recognized as an important factor associated with species invasions. Consequently, there is increasing need to develop solutions that combine economics and ecology to inform invasive species management. We developed a model combining economic, ecological, and sociological factors to assess the degree to which economic policies can be used to control invasive plants. Because invasive plants often spread across numerous properties, we explored whether property owners should manage invaders cooperatively as a group by incorporating the negative effects of invader spread in management decisions (collective management) or independently, whereby the negative effects of invasive plant spread are ignored …