Digital Commons Network^™

Mercury Methylation In Oxic Sub-Polar Marine Regions Linked With Nitrification, Marissa Collins Despins

Browse all Theses and Dissertations

Methylmercury (MeHg) is a neurotoxin that bioaccumulates to potentially harmful concentrations in Arctic marine wildlife and in those that consume them. Monitoring and modeling MeHg bioaccumulation and biogeochemical cycling in the ocean requires understanding of the mechanisms behind net mercury (Hg) methylation. The key functional gene for Hg methylation, hgcAB, is widely distributed throughout ocean basins and spans multiple microbial phyla. While multiple microbially-mediated anaerobic pathways for Hg methylation are known, in the ocean, the majority of hgcA homologs have been found in oxic subsurface waters, in contrast to other ecosystems. In particular, microaerophilic Nitrospina, a genera of nitrite-oxidizing bacteria …

Ms Environmental Biology Capstone Project, Dylan Brown

Regis University Student Publications (comprehensive collection)

Chapter 1- Revisiting Tamarisk Invasion in Riparian Ecosystems: An Argument Against Single Species Management of the Southwestern Willow Flycatcher (Empidonax traillii extimus)

Chapter 2- Temporal Trends of Tamarisk Remediation to Native Vegetation Establishment

Chapter 3- Assessing Effectiveness of Tamarisk Removal Treatments Through a Meta Regression Analysis

Chapter 4- Legal Challenges of Tamarisk Removal in the Southwestern United States

Root Phenotyping Of Peptide-Treated Glycine Max, Salem Jackson, Fiona Goggin

Inquiry: The University of Arkansas Undergraduate Research Journal

Plant elicitor peptides (Peps) – endogenous chains of amino acids involved in natural plant defense – have been shown to decrease damage from herbivores and pathogens by inducing an immune response, increasing the emission of volatile organic compounds (VOCS), transcripts, and metabolites. Exogenous treatment of soybean seeds with plant elicitor peptide GmPep3 has been shown to induce these broad-spectrum defenses and offers a new method for increasing crop yield. However, the effects of GmPep3 on indicators of soybean health – root characteristics, growth stages, etc. – have not been fully realized. Using the root-phenotyping platform RhizoVision Explorer, several root traits …

Ms Environmental Biology Capstone Project, Samantha Ortega

Regis University Student Publications (comprehensive collection)

This project is presented in partial fulfillment of the requirements for the degree Masters of Science in Environmental Biology at Regis University. Chapter 1 is a literature review that discusses the management implications of designing bird habitat on anthropogenic structures. Chapter 2 is a grant proposal to explore niche dominance by anthropophilic bird species in Denver, CO. Chapter 3 is a journal manuscript discussing how musth impacts captive bull Asian elephant (Elephas maximus) behavior at Denver Zoo. Finally, Chapter 4 is a stakeholder analysis for Northern Bobwhite recovery at Bridgestone-Firestone Centennial Wilderness Area, White County, Tennessee.

Soil Resilience And Arbuscular Mycorrhizal Fungi: How Fungi Can Inform Climate Change Mitigation And Adaptation In Maya Milpa Management, Courtney Mathers

Electronic Theses and Dissertations

In Mexico’s state of Yucatán, climate change impacts like prolonged and less predictable dry season length are manifesting as threats to agricultural production and food security. Nearly two thirds of Yucatán’s population is indigenous, many of whom live in rural communities that rely on rainfed subsistence agriculture (INEGI 2015). Ensuring sufficient food production in the face of climate change relies on the quality of agricultural soils. With both mismanagement of agricultural soils and climate change posing as threats to food production in Mexico, soil management practices that increase a soil quality should be identified and promoted. The primary objective of …

Modulation Of Human Gut Microbiota Through Dietary Associations, Sumudu Sasanka Rajakaruna

Browse all Theses and Dissertations

Study of human gut microbiota is becoming widely popular in recent years, especially due to numerous beneficial aspects attributed to this diverse and complex microbial communities. Followingly, there is a keen interest in understanding the dynamics and subsequent modulation of human gut microbiota, from a health perspective. Diet is considered significant in shaping gut microbiota community and functions, predominantly due to dietary macro and micronutrient content. Subsequently, a plethora of research is carried out on the effects of dietary nutrients on gut microbiota. Dietary patterns, quality of the diet, differences in food preparation methods, physiological and chemical changes occurred during …

Decolorization Of Synthetic Textile Dyes By Fungal Endophytes Isolated From The Leaves Of Philippine Mangrove (Avicennia Marina), Steve P. Obanan, Resureccion B. Sadaba, Pamela Alva-Gatchalian, Annabelle V. Cadiz, Evelyn M. Basilio, Dennis B. Bela-Ong

Biology Faculty Publications

Textile dyes in wastewater can be harmful pollutants when released into the environment without treatment. Biodegradation of textile dye effluents by different microbes, including fungi, has become popular as an alternative to physicochemical methods. The mangrove Avicennia marina is known to harbor endophytic fungi which have the potential to carry out dye degradation. Therefore, this study assessed the ability to decolorize synthetic dyes of endophytic fungi isolated from the leaves of A. marina. Of the nine fungal endophytes, Aspergillus niger, Syncephalastrum racemosum and Penicillium citrinum exhibited the highest mycelial growths in solid media, while all endophytes adsorbed Congo red. Through …

Evaluating The Effectiveness Of Readiness Assurance Testing As Part Of Team-Based Ecology Instruction, Danielle Berger, Larkin Powell

School of Natural Resources: Faculty Publications

Readiness Assurance Testing (RAT) incorporates content recall, immediate feedback and peer instruction, three strategies known to enhance student learning, into a single classroom activity. While iRAT and tRAT assessments are promising instructional tools, they are time-intensive to administer.

1.Do iRAT/tRAT tests promote student retention of content better than other in-class activities, justifying the investment of instructional time? 2.Are iRAT/tRAT tests beneficial across the spectrum of academic performance?

• Students get a larger proportion of RAT questions correct on exams than other multiple choice questions (Table 1, RAT~MC Intercept), supporting the claim that this instructional technique provides better content-retention than other …

Natural Resource System Size Can Be Used For Managing Recreational Use, D. S. Kane, K. L. Pope, K. D. Koupal, M. A. Pegg, C. Chizinski, M. Kaemingk

School of Natural Resources: Faculty Publications

No abstract provided.

Nebraska Water Center Annual Report 2022, Nebraska Water Center, Daugherty Water For Food Global Institute

Nebraska Water Center: Administrative Materials

CONTENTS

Overview: The Nebraska Water Center (https://watercenter.unl.edu)

Fast Facts: NWC 2022 Snapshot

Our Work

Water Sciences Lab Sees Rapid Growth in 2022 (https://watercenter.unl.edu/water-sciences-laboratory2)

WSL is Key to AltEn Contamination Monitoring (https://go.unl.edu/mead)

Know Your Well Project Enters Third Phase (https://knowyourwell.unl.edu)

Computer Science Students Build New Platform for Know Your Well Data Collection

Water Sciences Laboratory Helps Nebraska Tackle Nitrate (https://watercenter.unl.edu/water-sciences-laboratory2)

Nebraska Rural Poll Includes Water Quality Questions (https://ruralpoll.unl.edu and https://go.unl.edu/nitrate_strategy)

NWC Holds Platte River Basin Conference (https://watercenter.unl.edu/2022-nebraska-water-conference)

Spring Seminar Series (https://watercenter.unl.edu/spring-seminar-series)

Water Center Undergoes Five-Year …

No Panacea Attractant For Wild Pigs (Sus Scrofa), But Season And Location Matter, Nathan P. Snow, Caitlin A. Kupferman, Michael J. Lavelle, Kim M. Pepin, Madeline H. Melton, Whitney J. Gann, Kurt C. Vercauteren, James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are a prolific invasive species throughout many regions of the world that cause extensive economic and environmental damage. Trapping is a common strategy for reducing their populations with baits (i.e., food) and attractants (e.g., scents) used to lure wild pigs into traps. However, there is little information on which scent attractants may attract wild pigs more readily and rapidly across regions and seasons. We examined 60 scent attractants for wild pigs that could be used to increase trapping success across three seasons (winter, spring, and fall) and in two geographic regions, including a warm …

Predation Thresholds For Reintroduction Of Native Avifauna Following Suppression Of Invasive Brown Treesnakes On Guam, Robert M. Mcelderry, Eben H. Paxton, Andre V. Nguyen, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

The brown treesnake (BTS) (Boiga irregularis) invasion on Guåhan (in English, Guam) led to the extirpation of nearly all native forest birds. In recent years, methods have been developed to reduce BTS abundance on a landscape scale. To help assess the prospects for the successful reintroduction of native birds to Guåhan following BTS suppression, we modeled bird population persistence based on their life history characteristics and relative sensitivity to BTS predation. We constructed individual-based models and simulated BTS predation in hypothetical founding populations for each of seven candidate bird species. We represented BTS predation risk in two steps: …

Conserving Endangered Black-Footed Ferrets: Biological Threats, Political Challenges, And Lessons Learned, Travis M. Livieri, Steven C. Forrest, Marc R. Matchett, Stewart Breck

United States Department of Agriculture Wildlife Services: Staff Publications

There may be few stories in the annals of wildlife management that are as dramatic as the near demise and comeback of the black-footed ferret (Mustela nigripes). Endemic only to North America, this charming little carnivore found only in the continent’s central grasslands was hardly known to science until the mid-20th century. By then, vast colonies of the prey it depended on for food and shelter, the prairie dog (Cynomys spp.), had been wiped out through disease (sylvatic plague) and an agricultural industry with little tolerance for burrowing and grazing rodents. At its low point, the species’ …

Spatial Variability Of Silver Carp Population Demographics In A Large Tributary River, J. P. Werner, Q. J. Dean, Mark A. Pegg, M. J. Hamel

School of Natural Resources: Faculty Publications

No abstract provided.

An Evaluation Of Carbon Indicators Of Soil Health In Long-Term Agricultural Experiments, D. Liptzin, C. E. Norris, S. B. Cappellazzi, G. Macbean, Andrew E. Suyker Et Al.

School of Natural Resources: Faculty Publications

No abstract provided.

Does Fire And Herbicide Benefit Cattle Production In Invaded Grassland Landscapes?, N. A. Mcmillan, S. D. Fuhlendorf, L. E. Goodman, C. A. Davis, B. Luttbeg, R. G. Hamilton

School of Natural Resources: Faculty Publications

No abstract provided.

Species-Specific Responses To Landscape Features Shaped Genomic Structure Within Alaska Galliformes, Sarah A. Sonsthagen, Robert E. Wilson, Sandra L. Talbot

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Aim: Connectivity is vital to the resiliency of populations to environmental change and stochastic events, especially for cold-adapted species as Arctic and alpine tundra habitats retract as the climate warms. We examined the influence of past and current landscapes on genomic connectivity in cold-adapted galliformes as a critical first step to assess the vulnerability of Alaska ptarmigan and grouse to environmental change. We hypothesize that the mosaic of physical features and habitat within Alaska promoted the formation of genetic structure across species.

Location: Alaska, United States of America.

Taxa: Ptarmigan and Grouse (Galliformes: Tetraoninae).

Methods: We collected double digest restriction-site- …

Greater Loss And Fragmentation Of Savannas Than Forests Over The Last Three Decades In Yunnan Province, China, R Sedricke Lapuz, Angelica Kristina M. Jaojoco, Sheryl Rose C. Reyes, Jose Don T. De Alban, Kyle W. Tomlinson

SOSE Affiliate: Manila Observatory

Yunnan Province, southwest China, has a monsoonal climate suitable for a mix of fire-driven savannas and fire-averse forests as alternate stable states, and has vast areas with savanna physiognomy. Presently, savannas are only formally recognised in the dry valleys of the region, and a no-fire policy has been enforced nationwide since the 1980s. Misidentification of savannas as forests may have contributed to their low protection level and fire-suppression may be contributing to vegetation change towards forest states through woody encroachment. Here, we present an analysis of vegetation and land-use change in Yunnan for years 1986, 1996, 2006, and 2016 by …

Spatial And Temporal Variability Of Mercury In Upper And Lower Red Lake Walleye, Tyler Orgon

Biology Graduate Theses

Mercury is a global pollutant that is released into our environment by natural and anthropogenic processes resulting in extensive studies conducted on mercury cycling in aquatic ecosystems which has led to the issuance of human-health-based fish-consumption advisories. We examined total mercury concentrations in Walleye Sander vitreus from Upper and Lower Red Lakes, located in north central Minnesota, between 2019 and 2020. Upper and Lower Red Lake form a contiguous water body consisting of two large (483.1 and 665.6 km2, respectively) basins that are naturally connected by a 1.4 km-wide strait. Both basins are important fisheries for recreation, subsistence, and commercial …

Co-Producing A Shared Characterization Of Depredation In The Gulf Of Mexico Reef Fish Fishery: Comprehensive Report, James M. Drymon, Ana Osowski, Amanda Jargowsky, Matthew Ajemian, Angela Collins, Bryan Fluech, Steven Gray, Julie Lively, Steven Scyphers

CREC Publications

Depredation, defined as the partial or complete removal of a hooked fish by a non-target species, is a cryptic form of mortality that can affect the accuracy of stock assessments and species management efforts. Accounting for depredation is crucial to minimize uncertainty in stock assessment models and to obtain accurate and reliable fisheries catch data. If these interactions are frequent, failure to properly quantify this form of mortality can lead to the underestimation of reef fish population removals, inappropriate harvest recommendations, and stakeholder unrest. In recent years, depredation has escalated in the Gulf of Mexico (GoM) reef fish fishery. Although …

"Reeling In" Juvenile Sportfish Through Coastal Habitat Restoration: Population, Community, And Trophic Responses In The Indian River Lagoon, Florida, Jennifer Loch

Electronic Theses and Dissertations, 2020-2023

Coastal habitats provide crucial nursery habitat for predatory fishes, but they are in decline worldwide, impacting economically important fisheries. Habitat restoration can simultaneously mitigate the effects of habitat loss and benefit predators (e.g., sportfish), although this relationship is understudied. Here, the response of juvenile sportfish to oyster reef and living shoreline restoration is compared to controls in the Indian River Lagoon, Florida prior to and following restoration for up to three years through examination of community (diversity, assemblage), population (abundance), biometric (size, body condition), ontogenetic, and trophic (gut contents, stable isotopes) dynamics. Stable isotopes were used to quantify dietary history, …

Long Island Horseshoe Crab Network Annual Inventory Report, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli

CERCOM Reports

CERCOM monitors 115 beach locations from Brooklyn – Montauk during the optimal Limulus Polyphemus breeding season. These beach surveys take place for approximately 15 weeks, ranging from May - August. These beach locations are marked specifically using GPS coordinates, to assure the same location is visited each year. Students and volunteers are required to attend a HSC Survey training orientation led by CERCOM’s research assistant, Mr. Kyle Maurelli. Surveying is done around tide and moon cycles (New/Full Moon). Each site takes about 1-2 hours and data is recorded along an approximate 1 mile distance. Walking along the water’s edge the …

The Implementation Of Advanced Digitalization In The Oil And Gas Industry, Ensieh Rezafar

Walden Dissertations and Doctoral Studies

AbstractThe immature advanced digitalization in the oil and gas industry can limit access to the potential value of mature progressive digitalization. Oil and gas leaders must expedite the implementation of advanced digitalization to increase organizational proficiencies and reduce costs and losses. Grounded in Pettigrew and Whipp’s dimensions of strategic change theory, the purpose of this qualitative multiple case study was to explore strategies some leaders in the oil and gas industry used to implement advanced digitalization. The participants were seven leaders in two oil service companies in North America involved in the successful implementation of progressive digitalization. Data were collected …

Strategies For Achieving Sustainability Of Small Business Restaurants, Tanisha Thomas-Beard

Walden Dissertations and Doctoral Studies

Many small business restaurant owners perform unprofitably and fail within 5 years of opening. Small business restaurant owners are concerned about sustainability as approximately 50% of small businesses that start up do not last beyond the fifth year. Grounded in the general systems theory, the purpose of this qualitative multiple case study was to explore strategies small business restaurant owners use to grow and maintain profitability to sustain business beyond 5 years. The participants were five small business restaurant owners in the Southeastern region of the United States who sustained their business beyond 5 years. The data were analyzed using …

Mining-Contaminated Sediment And Metal Storage In Channel Deposits In Turkey Creek, Tri-State Mining District, Missouri And Kansas, Max Quinn Hillermann

Graduate Theses/Dissertations

The Joplin subdistrict, within the Tri-State Mining District (TSMD), was a major producer of lead (Pb) and zinc (Zn) ore between the 1880s to 1920s. Metalliferous mining wastes are still stored in the channel deposits of local streams raising environmental and health concerns. This study quantifies the volume, sediment size, and metal concentrations in channel bed, bar, bench, and chute deposits to quantify the spatial variability of contaminated sediment storage in Turkey Creek (119 km²). Sample reaches (n=14) contained metal concentrations elevated above the Tri-State Mining District specific probable effects concentration at every site with mean concentrations in …

Foot Injuries In Michigan, Usa, Gray Wolves (Canis Lupus), 1992–2014, Daniel J. O'Brien, Dean E. Beyer Jr., Erin Largent, Julie R. Melotti, Caitlin N. Ott-Conn, Donald H. Lonsway, Thomas M. Cooley, Robert Atkinson, Michelle Clayson, Kelly A. Straka

United States Department of Agriculture Wildlife Services: Staff Publications

The range of gray wolves (Canis lupus) in the contiguous US is expanding. Research and monitoring to support population recovery and management often involves capture via foothold traps. A population-level epidemiologic assessment of the effect of trap injuries on wolf survival remains needed to inform management. We describe the baseline rate, type, and severity of foot injuries of wolves born 1992–2013 in Michigan’s Upper Peninsula, evaluate the reliability of field-scoring trap-related injuries, and the effect of injuries on wolf survival. We assessed foot injuries by physical and radiographic exam at postmortem and/or time of capture for 351 wolves using the …

Olfactory Lures In Predator Control Do Not Increase Predation Risk To Birds In Areas Of Conservation Concern, Page Klug, Amy A. Yackel Adams, Robert N. Reed

United States Department of Agriculture Wildlife Services: Staff Publications

Context. Lethal control of predators is often undertaken to protect species of conservation concern. Traps are frequently baited to increase capture efficacy, but baited traps can potentially increase predation risk by attracting predators to protected areas. This is especially important if targeted predators can escape capture due to low trap success. Snake traps using live mouse lures may be beneficial if traps effectively remove snakes in the presence of birds and do not attract additional snakes to the area.

Aims. The present study evaluated whether mouse-lure traps in areas occupied by birds (simulated by deploying birdlure traps) could influence predation …

Wild Pig Removal Reduces Pathogenic Bacteria In Low-Order Streams, Sara A. Bolds, B. Graeme Lockaby, Latif Kalin, Stephen S. Ditchkoff, Mark D. Smith, Kurt Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive wild pig populations have undergone enormous increases in the United States and particularly across the southern U.S. in recent years. High fecundity rates and abilities to adapt quickly to varied habitats have enabled pig populations to become entrenched and difficult to eliminate. The pigs cause many negative impacts on ecosystems including degradation of water quality through infusion of fecal contamination and other non-point source pollutants. Our goal was to determine the effects of pig removal on water quality in streams that were known to be significantly polluted by pig activity Bolds (J Environ Qual 50: 441–453, 2021). We compared …

Power In Numbers: An Abundance Of Small Corals Responsible For Storing Over Half Of The Carbon Stored By All Alaskan Primnoa Pacifica Deep-Sea Corals, Sylvie Alexander

Scripps Senior Theses

Gorgonian deep-sea corals (DSCs) are biologically linked to ocean carbon cycling converting ocean carbon to gorgonin and calcite in their skeletons. As such, gorgonian DSCs likely accumulate and store carbon in their skeleton throughout their lifespans, acting as carbon sinks on historic timescales. Yet, DSC carbon storage hasn’t been investigated to date. This study evaluates gorgonian DSC carbon storage capacity through an evaluation of the carbon stored by Alaskan Primnoa pacifica corals. The development of a model relating coral height to biomass in specimens with this data available was used to determine biomass values in a suite of Alaskan P. …

Review Of Spiders Of North America, By Sarah Rose, Michael L. Draney

The Prairie Naturalist

A field guide to spiders, the dominant terrestrial predator group, has long been a desire for North American naturalists, biologists, and spider fans, but not surprisingly, the first “real” field guide has been a long time coming. The diversity of spiders, with over 50,000 known species globally (World Spider Catalog 2022) and around 4,000 in North America north of Mexico (Rose 2022), is well beyond the diversity of more traditional field guide targets such as birds (about 1,000 species north of Mexico; American Birding Association 2022) or butterflies (about 725 species north of Mexico; North American Butterfly Association 2022). Also, …