Digital Commons Network^™

Effect Of Natural Blue-Green Algal Cells Lysis On Freshwater Quality, Kessy Kilulya, Titus Msagati, Bhekie Mamba

Tanzania Journal of Science

Blue-green algae grow in freshwater bodies when they are provided with suitable factors such as nutrients and appropriate weather conditions. Their cell lysis occurs naturally when they encounter unfavourable conditions.  This study reports on the types and amounts of fatty acids added into freshwater due to the algal cell lysis. The investigation on the amount of fatty acids released into water due to algal cells lysis was performed by placing samples in two compartments, one with no light allowing the algae cells to die while the other compartment was kept in favourable conditions enough to sustain the life of algae. …

"The Devil Is In The Details:" Inland Northwest Stakeholders’ Views On Three Forest-Based Bioenergy Scenarios, Soren Newman, Darin Saul, Robert Keefe, Ryan Jacobson, Tamara Laninga, Jillian Moroney

University Author Recognition Bibliography: 2017

Public and private initiatives are actively exploring a range of forest-based bioenergy development options in the Inland Northwest of the United States. These efforts are motivated in part by the potential to generate renewable energy while creating a market for forest residues that would facilitate hazardous fuels reduction and provide economic opportunities. Understanding stakeholders’ perspectives is critical to the feasibility and long-term viability of bioenergy projects. This study presents stakeholder perspectives on forest-based bioenergy development strategies for communities in the forested areas of Idaho, western Montana, eastern Washington, and eastern Oregon. We developed three scenarios based on bioenergy initiatives currently …

How Innovative Companies Gain From A Cap And Trade Agreement, Lucian Montgomery

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

The purpose of both a cap and trade agreement and a carbon tax is to reduce emissions by setting a price on carbon. However, that is where the similarities end.

A cap and trade agreement gives a certain amount of allowances to each company that adds up to an emissions cap, allows companies to trade them. Companies only pay for carbon emissions if they produce more than the amount of allowances they are given, either by paying penalties to the government, or by buying more allowances from other companies. This creates a market for allowances, and based on demand, sets …

Wind Is Nebraska’S Future, With Or Without The Clean Power Plan, Megan Pamperin

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

The Clean Power Plan was issued in October 2015. President Trump called for a review of the plan this March and on October 16^th, 2017 the EPA released a proposal to repeal it. The Clean Power Plan would have reduced Nebraska’s state emissions to 22,250,000 tons of carbon dioxide by 2024, down by about 5 million tons compared to 2012 emissions.¹ The new projection for 2020 without the plan is 34 million tons of CO₂ emitted.

Coal and other fossil fuel energy sources are the main culprits of these carbon emissions, and here in Nebraska coal …

A Framework For Linking Population Model Development With Ecological Risk Assessment Objectives, Sandy Raimondo, Matthew Etterson, Nathan Pollesch, Kristina Garber, Andrew Kanarek, Wade Lehmann, Jill Awkerman

United States Environmental Protection Agency: Publications

The value of models that link organism-level impacts to the responses of a population in ecological risk assessments (ERAs) has been demonstrated extensively over the past few decades. There is little debate about the utility of these models to translate multiple organism-level endpoints into a holistic interpretation of effect to the population; however, there continues to be a struggle for actual application of these models as a common practice in ERA. Although general frameworks for developing models for ERA have been proposed, there is limited guidance on when models should be used, in what form, and how to interpret model …

Automated Species Classification Methods For Passive Acoustic Monitoring Of Beaked Whales, John Lebien

LSU New Orleans Theses and Dissertations

The Littoral Acoustic Demonstration Center has collected passive acoustic monitoring data in the northern Gulf of Mexico since 2001. Recordings were made in 2007 near the Deepwater Horizon oil spill that provide a baseline for an extensive study of regional marine mammal populations in response to the disaster. Animal density estimates can be derived from detections of echolocation signals in the acoustic data. Beaked whales are of particular interest as they remain one of the least understood groups of marine mammals, and relatively few abundance estimates exist. Efficient methods for classifying detected echolocation transients are essential for mining long-term passive …

An Application Of M-Matrices To Preserve Bounded Positive Solutions To The Evolution Equations Of Biofilm Models, Richard S. Landry Jr.

LSU New Orleans Theses and Dissertations

In this work, we design a linear, two step implicit finite difference method to approximate the solutions of a biological system that describes the interaction between a microbial colony and a surrounding substrate. Three separate models are analyzed, all of which can be described as systems of partial differential equations (PDE)s with nonlinear diffusion and reaction, where the biological colony grows and decays based on the substrate bioavailability. The systems under investigation are all complex models describing the dynamics of biological films. In view of the difficulties to calculate analytical solutions of the models, we design here a numerical technique …

The Blurred Line Between Photic And Aphotic Environments: A Large Mexican Cave With Almost No Dark Zone, Luis M. Mejía-Ortíz, Tanja Pipan, David C. Culver, Peter Sprouse

International Journal of Speleology

Sistema Muévelo Rico is a 1.2 km long cave in Quintana Roo, less than 2 km from the Caribbean Sea. We measured illuminance to a level of 0.1 lux, organic matter (weight loss on ignition), temperature, and relative humidity. The last two were measured at hourly intervals for nearly one year. Approximately one-third of the cave has illuminance values greater than 0.01 lux, and most of the rest of the cave has light as well. Temperature and relative humidity were relatively constant, but they showed a daily cycle at all stations, albeit with different strengths. Organic matter averaged 8%, intermediate …

Testing The Underlying Chemical Principles Of The Biotic Ligand Model (Blm) To Marine Copper Systems: Measuring Copper Speciation Using Fluorescence Quenching, Tara N. Tait, James C. Mcgeer, Scott Smith

Chemistry Faculty Publications

Speciation of copper in marine systems strongly influences the ability of copper to cause toxicity. Natural organic matter (NOM) contains many binding sites which provides a protective effect on copper toxicity. The purpose of this study was to characterize copper binding with NOM using fluorescence quenching techniques. Fluorescence quenching of NOM with copper was performed on nine sea water samples. The resulting stability con- stants and binding capacities were consistent with literature values of marine NOM, show- ing strong binding with log K values from 7.64 to 10.2 and binding capacities ranging from 15 to 3110 nmole mg C ^{−1 …}

Predicted Suitable Habitat Declines For Midwestern United States Amphibians Under Future Climate And Land-Use Change Scenarios, Brock Struecker, Joseph Milanovich

Biology: Faculty Publications and Other Works

With current declines of vertebrate taxa meeting or exceeding those of historic mass extinction events, there is a growing need to investigate the main drivers of losses. Two of the main drivers of declines are global climate and land-use changes, both affecting multiple groups of taxa. Amphibians are at great risk from these two drivers of change and investigations into the impact of future change could assist with the formation of conservation plans to mitigate losses. Forecasting changes in suitable habitat with ecological niche modeling serves as a useful tool to begin to understand how species may respond to anthropogenic …

Cataloging Wonder: The Art And Science Of The Collection, Christine Metzger

The Transdisciplinary STEAM+ Journal

The Exploring Science in the Studio National Science Foundation grant funded three initiatives at California College of the Arts, a private four-year art and design college in the San Francisco Bay Area. The grant sponsored annual Science-in-the-Studio which embedded scientists into the art and design studio curriculum, the creation of Mobile Units for Scientific Exploration (MUSE) and a new collection of science materials, equipment, and natural specimens, and a national symposium on integrating science into the art and design studio curriculum. Approximately 30 SitS classes have been offered since 2010, and the Exploring Science in the Studio symposium was convened …

Remediation Strategies For Mercury Contaminated Lakes And Reservoirs Within The State Of California, Emily Chortek

Master's Projects and Capstones

Mercury is an environmental and public health concern due to its neurodegenerative effects and ubiquitous concentration within the environment. To mitigate these risks and reduce concentrations within the environment, remediation methods are necessary. The purpose of this paper is to investigate and evaluate the efficacy of a number of remediation options for mercury contaminated lakes and reservoirs in the State of California. This paper also identifies a number of challenges associated with the implementation of each method and provides recommendations for environmental managers to use when remediating mercury contaminated lakes. Hypolimnetic oxygenation (HOS) was found to be the least problematic …

Seasonal Resource Selection And Habitat Treatment Use By A Fringe Population Of Greater Sage-Grouse, Rhett Boswell

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Movement and habitat selection by Greater Sage-grouse (Centrocercus uropasianus) is of great interest to wildlife managers tasked with applying conservation measures for this iconic western species. Current technology has created small and lightweight GPS (Global Positioning Systems) transmitters that can be attached to sage-grouse. Using GIS software and statistical programs such as Program R, land managers can analyze GPS location data to assess how sage-grouse are geospatially interacting with their habitats. Within the Panguitch Sage-Grouse Management Area (SGMA) thousands of acres of land have been restored or manipulated to enhance sage-grouse habitat; this usually involves removal of pinyon pine …

Abiotic- And Biotic-Formation Of Manganese Oxides And Their Fate In Environmental Systems, Haesung Jung

McKelvey School of Engineering Graduate Student Theses & Dissertations

Manganese (hydr)oxide (Mn (hydr)oxide) minerals are ubiquitous in aquatic and terrestrial environments. These minerals have high surface areas and are highly sorptive and redox active. From decades of accumulated knowledge about natural redox cycling, we have found that Mn (hydr)oxides play critical roles as electron donors and acceptors in elemental geochemical cycling and biological metabolisms in nature. Thus, Mn (hydr)oxides have garnered increasing interest to understand natural systems. Considering the variety of redox reactions with Mn (hydr)oxides in nature, it is also expected that there should be diverse pathways to form Mn (hydr)oxides through abiotic and biotic processes. Previous studies …

Translating Statistical Species-Habitat Models To Interactive Decision Support Tools, Lyndsie S. Wszola, Victoria L. Simonsen, Erica F. Stuber, Caitlyn R. Gillespie, Lindsey N. Messinger, Karie L. Decker, Jeffrey J. Lusk, Christopher F. Jorgensen, Andrew A. Bishop, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Understanding species-habitat relationships is vital to successful conservation, but the tools used to communicate species-habitat relationships are often poorly suited to the information needs of conservation practitioners. Here we present a novel method for translating a statistical species-habitat model, a regression analysis relating ring-necked pheasant abundance to landcover, into an interactive online tool. The Pheasant Habitat Simulator combines the analytical power of the R programming environment with the user-friendly Shiny web interface to create an online platform in which wildlife professionals can explore the effects of variation in local landcover on relative pheasant habitat suitability within spatial scales relevant to …

Exploiting Synchrotron “Light” To Study Chemistry Of Trace Elements In Soils And Plants, Ryan Tappero

Sustainability Seminar Series

Biogeochemical studies often require characterization of elemental abundances and speciation in samples that are chemically and physically heterogeneous at the micrometer scale. Synchrotron radiation sources are ideal for developing high intensity, highly-focused X-ray probes for interrogating the speciation, transport, and reactions of trace elements in heterogeneous earth and biological materials with detection sensitivities in the attogram range and spatial resolutions less than 1 micrometer.

X-ray Fluorescence Microprobe (XFM) is a new, multi-modal X-ray fluorescence microscope recently installed at the National Synchrotron Light Source-II (NSLS-II) at Brookhaven National Laboratory. XFM has capabilities for X- ray micro-fluorescence (μ-XRF) imaging and tomography, X-ray …

Evaluation Of Cadmium Bioaccumulaiton Of Periphyton And Aquatic Invertebrates Within Tributaries Of The Buffalo National River, Jacob Rollins Mccauley

Student Theses and Dissertations

The Rush Mining District, located along the Buffalo River in Arkansas, has a significant history of metal-mining operations. The tails and spoils of these operations deposit heavy amounts of raw ore into streams, including the deposition of cadmium, a minor constituent. Periphyton and invertebrate samples from two creeks within the Rush Mining District were measured for cadmium. Additionally, two creeks with no history of mining were sampled. Periphyton samples from mining sites had significantly higher concentrations of cadmium than samples collected at control sites. Invertebrate samples were classified into trophic levels before analysis. Invertebrate samples collected at treatment sites only …

Biodiversity Of Larval And Adult Dragonflies And Damselflies (Odonata) Of Interdunal Wetlands At Saugatuck Harbor Natural Area, Devon Volz

Honors Theses

The effects of climate change on insects in the United States have yet to be fully understood. Research on the insect populations of Lake Michigan’s interdunal wetlands has been particularly limited. As these vibrant habitats are already at risk of destruction due to increased development, it is vital to have a working knowledge of the species that are living in the habitat. However, to date, there have been no studies on assemblages of interdunal wetlands in Michigan. Examining community compositions is critical to understanding the ecological problems that could occur in the future. This study is the first to look …

Assessing Preservation Priorities Of Caves And Karst Areas Using The Frequency Of Endemic Cave-Dwelling Species, Eugen Nitzu, Marius Vlaicu, Andrei Giurginca, Ioana N. Meleg, Ionut Popa, Augustin Nae, Ştefan Baba

International Journal of Speleology

Endemic and rare species as bioindicators of habitat vulnerability were used to develop protection and management plans for biotope prioritization (mainly islands habitats, lava tubes or groundwaters). Due to their narrow distribution, the endemic species (species confined to a restricted geographic area) are more susceptible to ecological disequilibrium and habitat loss than the widespread ones. Consequently, endemics become endangered in the context of ecological disturbance caused by anthropogenic pressure, making them suitable candidates to assess environmental preservation needs. Taking into consideration that most of the stygobitic and troglobitic species are endemic and confined to specific karst areas, based on their …

Optimization Of Parameters For The Densification (Pelletization) Of Cereal Crop Residues And Feasibility Study Of Pellet Plant Development In The State Of Arkansas From Economic Perspective, Shyam Thapa

Student Theses and Dissertations

Conventional cereal crop residues, namely, rice (Oryza sativa L.), corn (Zea mays L.), and wheat (Triticum aestivum L.) is very abundant and readily available widely. It has been a nuisance to agronomic producers to manage these immense “so-called wastes”. The Energy Independence and Security Act (EISA) promulgated by the United States and The EU’s renewable energy directive mandated the substantial incorporation of renewable energy in their final energy consumption. These led to the increase in R&D’s on biomass and bioenergy products in the United States as well. Hammer mill grinds of different cereal crop residues, rice, wheat, and corn, sieved …

Investigation Of The Effectiveness Of N, N-Dimethylformamide As A Solvent For Cdte Electrodeposition, Joshua Aaron Vangilder

Student Theses and Dissertations

The goal of this dissertation project was to investigate the viability of N, N-dimethylformamide (DMF) as a solvent for CdTe electrodeposition. The Taguchi Method was used to design a minimal set of experiments to determine this. The factors chosen were deposition voltage, solution composition, stir rate, and temperature. There were a total of nine experiments and 18 samples produced (2 per experiment). Optical absorbance data was collected for each film to approximate the bandgap of the material. This data was used to determine the optimal set of conditions and the relative significance of each factor to one another. It was …

Failing Food Supply: Permaculture's Potential, John Faltin

Department of Environmental Studies: Undergraduate Student Theses

Conventional agriculture is the currently leading production method to grow crops in the western hemisphere. Long-term sustainability of the system and all the components is secondary to producing high yields each growing season, which leads to issues such as erosion and reduced soil quality. Other agricultural production methods such as permaculture aim to build soil and improve quality every growing season. This experiment intends to look at the potential of permaculture to improve soil quality on small-scales at the end of each growing season. The parameters to gauge success are a larger concentration of macronutrients at the end of the …

Emulating Natural Disturbance Using Variable Retention Harvest Regimes: Measuring Short-Term Changes In The Avian Community And Understory Nest Survival, Jennifer L. Wilcox

Student Theses and Dissertations

Over the last 200 years, forests of the eastern United States were largely cleared for industrial and agricultural purposes, and subsequent regrowth has resulted in mostly even-aged, closed canopy stands. Furthermore, dynamic ecological conditions including windthrow, ice storms, floods, fires, tree senescence, and insect outbreaks, which are necessary for maintaining healthy forest ecosystem functions and biodiversity, have become infrequent and/or do not have the same effects in contemporary forests as they did in old growth systems. This has partially led to declines in a number of disturbance-dependent and early-successional avian species, and a need for harvest prescriptions that emulate these …

Causes And Consequences Of Range Expansion In The Genus Tyrannus, Alexander Joseph Worm

Student Theses and Dissertations

Investigating factors that influence species’ ranges and the potential consequences arising from expansion is vital in successfully predicting future distributions. Species-habitat associations are considered to be fixed, but if they are variable, inaccurate forecasts may occur. Additionally, hybridization with heterospecifics can affect species’ ranges, possibly preventing successful expansion. Here, I used two expanding bird species, Scissor-tailed Flycatcher (Tyrannus forticatus) and Western Kingbird (T. verticalis), to assess how differential habitat selection and hybridization may influence range expansion. First, I explored variation in habitat selection behavior of Scissor-tailed Flycatchers by comparing habitat selection patterns at the periphery with the historic core of …

An Experimental Determination Of The Quasi-Rest Potential Of Copper Indium Disulfide Utilizing The Novel Open-Circuit Voltage Transient, Michael Jason Newell

Student Theses and Dissertations

Environmental sustainability requires resource management that takes future generations into account. The present generation has witnessed changes across the planet, unprecedented in human history and disrupting communities and cities around the world, due to shifting global climate. This is primarily the result of fossil fuels, which powered modern civilization but dramatically increased levels of CO2 and other greenhouse gases, and may be the least sustainable aspect of human civilization. Chapter 1 justifies the research from an environmental perspective and provides initial research parameters. Thin film photovoltaic (PV) modules are reported the most sustainable among energy production technologies currently available. Electrodeposited …

The Value Of Native Plants And Local Production In An Era Of Global Agriculture, Oren Shelef, Peter J. Weisberg, Frederick D. Provenza

Wildland Resources Faculty Publications

For addressing potential food shortages, a fundamental tradeoff exists between investing more resources to increasing productivity of existing crops, as opposed to increasing crop diversity by incorporating more species. We explore ways to use local plants as food resources and the potential to promote food diversity and agricultural resilience. We discuss how use of local plants and the practice of local agriculture can contribute to ongoing adaptability in times of global change. Most food crops are now produced, transported, and consumed long distances from their homelands of origin. At the same time, research and practices are directed primarily at improving …

Non-Native Mangroves (Rhizophora Mangle) Of Moloka'i, Hawai'i: A Socio-Ecological Analysis, Casey Lynette Lewis

Dissertations and Theses

The formation of novel ecosystems by non-native species poses management challenges that are both socially and ecologically complex. This complexity necessitates consideration of both ecological dynamics and social attitudes and perceptions. Red mangrove propagules were introduced to Moloka'i, Hawaii in 1902 to mitigate the effects of soil erosion and they have since spread along the coast and to adjacent islands creating novel habitat. Non-native mangroves in Hawai'i present a unique case study to examine diverse social attitudes and perceptions resulting from a long history of land cover transformations on the Hawaiian Islands, socio-cultural diversity of involved stakeholders, and the potential …

The Firece Green Fire: Vol. 8 Issue 11, Wofford College Environmental Studies Program

The Fierce Green Fire

No abstract provided.

Historical Change Of Seagrasses In The Mississippi And Chandeleur Sounds, Linh Thuy Pham

Dissertations

Seagrasses are important coastal resources facing numerous stressors, and losses have been documented from local to global assessments. Under the broad theme of habitat loss and fragmentation, a study of historical change in total area and landscape configuration of seagrasses in the Mississippi and Chandeleur Sounds was conducted. Mapping data was collated from a multitude of previous projects from 1940 to 2011.

Comparisons of seagrass area among various studies that used different mapping methods can result in overestimation of area change and misleading conclusions of change over time. The vegetated seagrass area (VSA) data were generalized to a common resolution …

Northern Eurasia Future Initiative (Nefi): Facing The Challenges And Pathways Of Global Change In The Twenty-First Century, Pavel Groisman, Herman Shugart, David Kicklighter, Geoffrey Henebry, Nadezhda Tchebakova, Shamil Maksyutov, Erwan Monier, Garik Gutman, Sergey Gulev, Jiaguo Qi, Alexander Prishchepov, Elena Kukavskaya, Boris Porfiriev, Alexander Shiklomanov, Tatiana Loboda, Nikolay Shiklomanov, Son Nghiem, Kathleen Bergen, Jana Albrechtová, Jiquan Chen, Maria Shahgedanova, Anatoly Shvidenko, Nina Speranskaya, Amber Soja, Kirsten De Beurs, Olga Bulygina, Jessica Mccarty, Qianlai Zhuang, Olga Zolina

GSCE Faculty Publications

During the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socio-economic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can have global consequences. The Northern Eurasia Future Initiative (NEFI) has been designed as an essential continuation of the Northern Eurasia Earth Science Partnership Initiative (NEESPI), which was launched in 2004. NEESPI sought to elucidate all aspects of ongoing environmental change, to inform societies and, thus, to better prepare societies for future developments. A key principle of NEFI is that these developments …