Digital Commons Network^™

Assessing Intra-Urban Particulate Matter (Pm2.5) Concentrations At The Lower Rio Grande Valley (Rgv), South Texas, Usa, Using Low-Cost Sensors, Esmeralda Mendez

Theses and Dissertations

Rapid technological developments of novel low-cost air quality sensors enable long-term ambient monitoring in neighborhood areas. In this study, spatial and temporal trends are analyzed by localized level monitoring with low-cost sensors (TSI BlueSky Air Quality Monitor). Eleven low-cost sensors were deployed across the Lower Rio Grande Valley, South Texas region: Brownsville, Edinburg, Weslaco, and Port Isabel. 24-hour PM2.5 concentrations are correlated with PM2.5 from existing Texas Commission on Environmental Quality (TCEQ) Continuous Ambient Monitoring Stations (CAMSs) to express temporal and spatial heterogeneity from March 01, 2021, to March 31, 2022. Results indicated the deployed low-cost sensors as a better …

Growth And Reproduction In Gulf Of Mexico Black Corals (Antipatharians) In Field And Laboratory Studies, Victoria E. Salinas

Theses and Dissertations

Black corals provide an important ecosystem of marine life and are found throughout all the oceans of the world at depths between 2 and 8,600 m. However, little is understood about their life history and the factors that control the distribution of black corals, particularly in the Gulf of Mexico (GoM). Given the impacts of the Deepwater Horizon oil spill on soft corals (e.g., black corals and octocorals) in the GoM, studies of their growth and reproductive biology in both natural and aquaculture environments are crucial for restoration efforts. The objectives of this study were to examine reproductive processes, compare …

Network Analysis Of Scientific Research In The Gulf Of Mexico, Juliet S. Vallejo

Theses and Dissertations

The Gulf of Mexico ecosystem represents a significant management challenge in its 3,423-mile coastline and transnational regulatory setting, along five states from the United States, six states from Mexico, and Cuba which borders the southeastern quadrant. Providing various resources to the regional economies, the continued success of these resources depends on the collaboration among transnational participants in bringing together complementary skills and multidisciplinary approaches to producing, circulating, and utilizing scientific knowledge. Using bibliometric analysis of Gulf of Mexico-related published research over 18 years from 2000 to 2018 allows for identifying organizations, their connections, and trends in the production of scientific …

Nestedness And Modularity Of Avian Metacommunities Across Gradients Of Chesapeake Bay Island Characteristics, Grant Walter Bowers

Biological Sciences Theses & Dissertations

Islands are not only great models for understanding the ways in which communities are linked by the dispersal of their members to form metacommunities, but are of particular interest to conservationists. One important aspect of metacommunity structure is the degree of nestedness—whether or not less speciose communities are perfect subsets of more speciose communities. Another important metric of metacommunity structure is modularity—the degree to which communities belong to modules composed of other communities that share the same species but have little species overlap with communities from different modules. Environmental gradients have received insufficient attention as predictors of metacommunity nestedness and …

In Vivo Efficacy Of Pyrantel Pamoate As A Post-Exposure Prophylactic For Rat Lungworm (Angiostrongylus Cantonensis), John Jacob, Argon Steel, Lisa Kaluna, Steven Hess, Israel Leinbach, Carmen Antaky, Robert Sugihara, Lindsey Hamilton, Peter Follett, Kathleen Howe, Steven Jacquier, Supakit Wongwiwatthananukit, Susan Jarvi

United States Department of Agriculture Wildlife Services: Staff Publications

Rat lungworm (Angiostrongylus cantonensis) is a neurotropic nematode, and the leading cause of eosinophilic meningitis worldwide. The parasite is usually contracted through ingestion of infected gastropods, often hidden in raw or partially cooked produce. Pharmaceutical grade pyrantel pamoate was evaluated as a post-exposure prophylactic against A. cantonensis. Pyrantel pamoate is readily available over-the-counter in most pharmacies in the USA and possesses anthelmintic activity exclusive to the gastrointestinal tract (GIT). Administering pyrantel pamoate immediately after exposure should theoretically paralyze the larvae in the GIT, causing the larvae to be expelled via peristalsis without entering the systemic circulation. In this study, pyrantel …

Current Ecotoxicity Testing Needs Among Selected U.S. Federal Agencies, Patricia Ceger, Natalia Garcia-Reyero Vinas, David Allen, Elyssa Arnold, Raanan Bloom, Jennifer C. Brennan, Carol Clarke, Karen Eisenreich, Kellie Fay, Jonathan Hamm, Paula F.P. Henry, Katherine E. Horak, Wesley Hunter, Donna Judkins, Patrice Klein, Nicole Kleinstreuer, Kara Koehrn, Carlie A. Lalone, James P. Laurenson, Jessica K. Leet, Anna Lowit, Scott G. Lynn, Teresa Norberg-King, Edward J. Perkins, Elijah J. Petersen, Barnett A. Rattner, Catherine S. Sprankle, Thomas Steeger, Jim E. Warren, Sarah Winfield, Edward Odenkirchen

United States Department of Agriculture Wildlife Services: Staff Publications

U.S. regulatory and research agencies use ecotoxicity test data to assess the hazards associated with substances that may be released into the environment, including but not limited to industrial chemicals, pharmaceuticals, pesticides, food additives, and color additives. These data are used to conduct hazard assessments and evaluate potential risks to aquatic life (e.g., invertebrates, fish), birds, wildlife species, or the environment. To identify opportunities for regulatory uses of non-animal replacements for ecotoxicity tests, the needs and uses for data from tests utilizing animals must first be clarified. Accordingly, the objective of this review was to identify the ecotoxicity test data …

Defining An Epidemiological Landscape That Connects Movement Ecology To Pathogen Transmission And Pace-Of-Life, Kezia Manlove, Mark Wilber, Lauren White, Guillaume Bastille-Rousseau, Anni Yang, Marie L.J. Gilbertson, Meggan E. Craft, Paul C. Cross, George Wittemyer, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Pathogen transmission depends on host density, mobility and contact. These components emerge from host and pathogen movements that themselves arise through interactions with the surrounding environment. The environment, the emergent host and pathogen movements, and the subsequent patterns of density, mobility and contact form an ‘epidemiological landscape’ connecting the environment to specific locations where transmissions occur. Conventionally, the epidemiological landscape has been described in terms of the geographical coordinates where hosts or pathogens are located. We advocate for an alternative approach that relates those locations to attributes of the local environment. Environmental descriptions can strengthen epidemiological forecasts by allowing for …

Upland Migration Of Coastal Marshes As A Response To Sea Level Rise And Fire Management: Past, Present, And Predicted, Devin Jen

Master's Theses

Coastal marshes are one of the most productive and intensively used ecosystems in the world. However, they are under threat due to natural and anthropogenic stressors, such as sea level rise (SLR). SLR can cause marshes to drown, converting them to open water. Marshes can respond to SLR through landward migration when suitable habitat is available. My research focuses on the landward migration pattern and mechanisms. I evaluated the historical land cover changes at the Grand Bay National Estuarine Research Reserve and the Pascagoula River delta over two-time intervals since 1955 and focused on the forest-marsh dynamics. I found that …

Genomic Analysis And Characterization Of Surface Properties Of Naphthalene Degrading Acinetobacter Isolates, Gunn Emilie Berge

Graduate Theses and Dissertations (2019 - present)

No abstract provided.

Land Use/ Land Cover Change Patterns And Trends In Two Dryland Regions, Omar Sulaiman Belhaj

Open Access Theses & Dissertations

Development and climate change affect the environment in numerous ways and to varyingdegrees. This effect appears prominent and more influential in arid regions. Therefore, land use/ land cover in these regions experience profound changes such as plant cover decrease and extinction of some plant species. Also, land use/ land cover in these regions has critical impacts on the environment and its components, such as shrublands shrinking and losing the habitat of animal species. The degree of changes and effects reaches severe levels that become urgent to figure out the impacts and find solutions to stop or mitigate the negative consequences. …

Diverse Effects Of Ev Charging Infrastructure On Electric Power Distribution Systems, Travis Michael Moore Newbolt

Open Access Theses & Dissertations

The advanced technology of today has allowed for an avenue into cleaner forms of energy that will not only protect our environment but also continue to advance our society. Among the many forms of clean energy, electric vehicles (EV) have the potential to mitigate our consumption of fossil fuels in vehicle transportation industries. In the U.S. for 2021, EVs account for approximately 700,000 registrations. That number is projected to increase to 2 million by 2030. Although EVs do reduce the number of emissions when compared to an internal combustion engine, they do however shift the responsibility to utility companies to …

An Unmanned Surface Vehicle: Autonomous Sensor Integration System For Bathymetric Surveys, Fernando Sotelo Torres

Open Access Theses & Dissertations

Unmanned Surface Vehicles (USVs) have been applied to earth sciences, with only a few studies conducted in water environments, as these systems provide autonomous measurement capabilities and transferability to other environmental settings. In this thesis, a reliable, yet economical, USV has been developed for bathymetric surveying of lakes. The system combines an autonomous navigation framework, environmental sensors and a multibeam echosounder to collect submerged topography, temperature, windspeed and monitor the vehicle status during prescribed path planning missions.

The main objective of this study is to provide a methodological framework to build a USV, with independent decision-making, efficient control, and long-range …

Population Genetics Of Two Sympatric Species, The Round-Tailed Horned Lizard (Phrynosoma Modestum) And The Greater Earless Lizard (Cophosaurus Texanus), In The Indio Mountains Of West Texas, Logan Miles Horne

Open Access Theses & Dissertations

Population genetics of two sympatric species, the round-tailed horned lizard (phrynosoma modestum) and the greater earless lizard (cophosaurus texanus), in the Indio mountains of West Texas.

Exposure Of Candyland Red Tomatoes (¬Solanum Lycopersicum L.) To Various Metal Oxide Nanomaterials: Full Life Cycle And Assessment Of Fruit Quality, Jesus Manuel Cantu

Open Access Theses & Dissertations

The use of nanotechnology in agriculture has attained high interest to enhance crop production due to their unique properties. Moreover, metal oxide nanomaterials can potentially supplement nutrients, enhance plant growth, and crop production. When investigating fruits' nutritional quality, carbohydrates and phytonutrients (bioactive compounds) play important roles. Therefore, it is important to understand how nanomaterials will affect the quality of tomato fruits. In this dissertation, various metal oxides were synthesized and applied to Candyland Red tomato seedlings to assess the plant growth and tomato production. In the first investigation, Candyland Red tomatoes (Solanum lycopersicum) were exposed to synthesized pristine CuO and …

Water Sourcing Strategies Of Desert Vegetation In Varying Soil Textures With Vegetation Competition: A Stable Isotope Analysis, Martha Elizabeth Gardea

Open Access Theses & Dissertations

Recent studies have suggested an ecohydrological separation of water exists in the northern Chihuahuan Desert, where vegetation types, rainfall regimes, and location in the terrain seem to determine the type of water (e.g. isotopically depleted or enriched in 18O and 2H) plants are able to source and use throughout their growing cycle. That work found evidence of creosote (Larrea tridentata) and mesquite (Prosopis glandulosa) using tightly bound soil water at both a site on an ephemeral channel and a site in higher elevated flat area because the isotopic signature of plant water at the beginning of the study did not …

Characterization Of A Flex-Fuel Oxy-Combustion System Through Experimental Investigation And Computational Modeling, Md Mohieminul I. Khan

Open Access Theses & Dissertations

Oxy-fuel combustion has the potential to offer high thermal efficiency and lower pollutants emission compared to other existing combustion technologies. More than 63% of the worldâ??s electricity is produced by fossil fuel combustion which also is the major reason for greenhouse gas emissions. Oxy combustion offers a solution to it. Oxy combustion uses pure oxygen as an oxidizer instead of air which eliminates the NOx and SOx products from the exhaust. In oxy-combustion flue gas mainly consists of CO2 and water vapor. Furthermore, combustion in presence of pure oxygen results in higher flame temperature and hence promises higher thermal efficiency. …

Chihuahuan Desert Rock Pool Community Assemblages: Patterns Of Taxonomic Diversity, Joseph Lee Mcdaniel

Open Access Theses & Dissertations

As climate change continues to become more prevalent, increasing temperatures and altering precipitation patterns will disrupt the environmental balance of ecosystems and spark the imminent threat of a 6th mass extinction event. Many researchers believe this has already begun, as losses for numerous taxonomic clades have been well documented; however, the loss of invertebrates is still unknown and may be much more severe than those of other animal clades. A significant factor contributing to the shortfall of invertebrate biodiversity loss is rooted in the lack of understanding of the diversity and distribution of these animals. There is still much to …

Biological Interaction Of Mn-Based Nanomaterials With Capsicum Annuum L. Under Salinity Stress, Yuqing Ye

Open Access Theses & Dissertations

The foliar application of nanomaterials as a method to overcome abiotic stress is relatively new compared to their use as fertilizers or pesticides in agricultural practice. It is also vital to understand the interface between leaf and nanomaterials, as nanomaterials might translocate into crop edible tissues, thus, causing potential toxicity in living beings during food consumption. In this dissertation, salt-stressed Capsicum annuum L was exposed to manganese (Mn) -based nanomaterials (Mn2O3 nanoparticles (MnNPs) and graphene quantum dots doped with Mn (GQD-Mn)) at different stages (seed germination and full life cycle). The dissertation focuses on investigating the mechanism of how Mn-based …

Quantification Of Hydrologic Response To Forest Disturbance In Western U.S. Watersheds, Sara A. Goeking

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forested watersheds produce more than half of the water supply in the United States. Forests affect how precipitation is partitioned into available water versus evapotranspiration. This dissertation investigated how water yield and snowpack responded to forest disturbance following recent disturbances in western U.S. forests during the period 2000-2019.

Chapter 2 systematically reviewed 78 recent studies that examined how water yield or snowpack changed after forest disturbances. Water yield and snowpack often increased after disturbance, but decreased in some circumstances. Decreased water yield was most likely to occur following disturbances that did not remove the entire forest canopy. It was also …

A Dynamic Relationship With Wilderness: Comparing Day And Multi-Day Visitors' Indicators Of Quality In Wilderness Settings, Caleb Meyer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The length of stay in wilderness areas is declining and, in many areas, day visitors comprise most of all use. Most prior research exploring this trend took place in the 1990s and few studies of wilderness visitation account for the increase in outdoor recreation participation over the last decade. Lack of understanding surrounding this trend raises questions about managerial and philosophical approaches to the recreation-wilderness relationship. This study explored these topics within visitor use management approaches used by the National Park Service, which manages the proposed Glen Canyon Wilderness, near Escalante, Utah, where this research took place.

Results of this …

Conservation Conflict: Rare Plant Conservation And Energy Development And Potential In The Colorado Plateau, Joshua Carrell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Colorado Plateau provides numerous sources of energy, particularly natural oil and gas. This energy potential is being actively extracted for consumption on both public and private lands. Elements of biodiversity (e.g., listed and sensitive plant and animal species) are distributed among all land tenures, yet the laws protecting them can vary depending if they occur on public, private, or tribal land. Therefore, it is necessary to understand the geographic ranges of threatened, endangered, and sensitive species and their relationship to land ownership to preserve habitat and conserve species populations. I developed species distribution models (SDMs) to examine the predicted …

The Effect Of Species Choice, Seed Mix Composition, And Microtopography On Native Plant Restoration In Great Salt Lake Wetlands, Coryna Hebert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wetlands are important ecosystems that improve water quality, prevent floods, and provide wildlife habitat. As such, restoring native plants that promote wetland health is a high priority for land managers. However, there are many challenges to the restoration of native plants. In our study system (Great Salt Lake wetlands), many areas are invaded by the European grass, Phragmites australis. Phragmites grows in dense stands and displaces native plants. The reduction of native plant communities in Great Salt Lake wetlands is a major concern because these ecosystems provide habitat for millions of native birds. Managers have made successful efforts to …

Investigating Factors That Impact Income Generation And Distribution In Western National Park Gateway Communities, Elizabeth Depew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many rural towns in the western united states have come to be defined by high levels of tourism, seasonal residents, and migration driven by the desire to be close to natural amenities and the higher quality of life they afford. This shift is especially apparent in communities that are “gateways” to natural amenities such as national parks. Embracing this shift towards the “New West,” many community planners have heralded amenity-led development as a remedy to the waning feasibility of relying on agriculture and extractive industries. However, anecdotal evidence and several case studies indicate the factors which make these gateway communities …

Comparing Fecal Dna Capture-Recapture Methods To Traditional Mark-Resight Methods For Estimating Abundance Of Mule Deer On Winter Ranges, Andi M. Stewart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Well-designed monitoring strategies are required to obtain accurate estimates of population abundance, which is important for evaluating conservation and management strategies. Obtaining abundance estimates using traditional survey methods, like aerial surveys, is not possible in all scenarios and can be expensive and risky. One survey method that has gained popularity in the last decade is fecal DNA-based capture-recapture (CMR). However, this method has not been evaluated on winter ranges or in snowy, winter conditions.

My first objective was to implement fecal DNA CMR to estimate abundance of mule deer in the Round Valley and Goodale winter survey areas in the …

Conservation Genetics Of A Declining Bumble Bee In Western North America; The Influence Of Geography, Dispersal Limitation, And Anthopogenic Activity, Ashley T. Rohde

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Conservation biology addresses the problem of species loss by identifying species in need of protection. Conservation biology has subfields to address different aspects of biodiversity loss, including genetics and sociology. I used genetic approaches to assess the conservation status of western bumble bees, a bumble bee species of conservation concern.

The western bumble bee is a bumble bee species that ranges from Alaska to New Mexico and as far east as Wyoming and Colorado. This species is disappearing in some places. It may soon be listed as endangered in the United States and is already listed as endangered in parts …

Effects Of Excessive Soil Phosphorus Accumulation On Loblolly Pine (Pinus Taeda L.) Seedlings, Hannah C. Bays

Electronic Theses and Dissertations

Many landowners in East Texas apply poultry litter to pastures as a source of nitrogen (N) for forage crops. After many years of repeated poultry litter application, soils can accumulate extremely high extractable phosphorus (P) concentrations, sometimes over 1000 mg kg^-1 of plant available P. Landowners report the conversion of these pastures to loblolly pine (Pinus taeda L.) plantations is often problematic, with poor seedling survival and abnormal tree growth. This study was conducted to assess the effects of excessive soil phosphorus on loblolly pine seedlings. An outdoor pot study was conducted using bare root seedlings and triple …

Conservation Of Open-Canopy-Associated Wildlife: Multi-Scale Management Impacts On Imperiled Herpetofauna, Ethan Joseph Royal

Graduate Theses and Dissertations

The loss of open-canopy ecosystems throughout North America has precipitated declines in reptile and amphibian species associated with these habitat types. Current efforts to restore open-canopy ecosystems are underway in many areas, but the local distributions of, habitat characteristics required by and the effects of management actions on many herpetofauna species are poorly understood or entirely unknown. Research examining relationships among herpetofauna and their environments is often complicated by the extremely low detectability seen in many studies. We used landscape-scale, assemblage-level surveys to investigate the occupancy patterns and habitat associations of open-canopy-associated herpetofauna in two regions, as well as gain …

A Climate Of Confessionalization: Famine And Difference In The Late Ottoman Empire, Matthew Ghazarian

Environmental Science and Policy: Faculty Publications

After the 1877–78 Russo-Ottoman War, the Ottoman Empire saw the rise of ethnic and sectarian clashes in Anatolia, the Balkans, and elsewhere, and the task of explaining that rise remains unfinished. Many have examined the intellectual formations of ethnic and sectarian solidarities after 1878, but the availability of new ideas cannot alone account for their widespread uptake. Why after 1878 did ordinary people respond more to calls upon ethnic and sectarian solidarity? Drawing on sources surrounding the 1879 famine in the Ottoman East, this article steps away from imperial metropoles to examine overlapping environmental, financial, and technological disjunctures. Adopting the …

A Climate Resilience Research Renewal Agenda: Learning Lessons From The Covid-19 Pandemic For Urban Climate Resilience, Mark Pelling, Winston T. L. Chow, Eric Chu, Richard Dawson, David Dodman, Arabella Fraser, Bronwyn Hayward, Luna Khirfan, Timon Mcphearson, Anjal Prakash, Gina Ziervogel

Research Collection School of Social Sciences

Learning lessons from the COVID-19 pandemic opens an opportunity for enhanced research and action on inclusive urban resilience to climate change. Lessons and their implications are used to describe a climate resilience research renewal agenda. Three key lessons are identified. The first lesson is generic, that climate change risk coexists and interacts with other risks through overlapping social processes, conditions and decision-making contexts. Two further lessons are urban specific: that networks of connectivity bring risk as well as resilience and that overcrowding is a key indicator of the multiple determinants of vulnerability to both COVID-19 and climate change impacts. From …

El Niño And The Human-Environment Nexus: Drought And Vulnerability In Singapore 1877-1911, Fiona Williamson

Research Collection College of Integrative Studies

This chapter brings a climatic perspective to the study of Singaporean history by exploring the impacts of the strong El Niño inspired droughts of 1877, 1902 and 1911. The narrative focuses on unpacking the nexus of nature-inspired versus human-induced vulnerability to drought within the contexts of colonial urbanisation and looks at the short-to medium-term impacts of the events on society. It also explores how such events inspired new questions about the climate and regional teleconnections, as a wealth of evidence became available due to the increasingly connected nature of scientific institutions, scientific literature, and communications systems across the Indian Ocean …