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Articles 1 - 30 of 2039

Full-Text Articles in Life Sciences

Positron Emission Tomography In Oncology And Environmental Science, Samantha Delaney Jun 2024

Positron Emission Tomography In Oncology And Environmental Science, Samantha Delaney

Dissertations, Theses, and Capstone Projects

The last half century has played witness to the onset of molecular imaging for the clinical assessment of physiological targets. While several medical imaging modalities allow for the visualization of the functional and anatomical properties of humans and living systems, few offer accurate quantitation and the ability to detect biochemical processes with low-administered drug mass doses. This limits how physicians and scientists may diagnose and treat medical issues, such as cancer, disease, and foreign agents.

A promising alternative to extant invasive procedures and suboptimal imaging modalities to assess the nature of a biological environment is the use of positron emission …


Effect Of Sex On The Accumulation Of Hepatic Mercury In Mallards Wintering In Louisiana, Latorya E. Mason May 2024

Effect Of Sex On The Accumulation Of Hepatic Mercury In Mallards Wintering In Louisiana, Latorya E. Mason

Master's Theses

The increase in mercury production through anthropogenic activities has led to a global crisis of mercury pollution that poses a significant threat to the health of both humans and wildlife. Aquatic ecosystems are especially at risk due to the creation of methylmercury, a toxic form of mercury, by sulfate-reducing bacteria in anoxic sediments and soils. Methylmercury enters the food chain where it bioaccumulates in individual organisms and then biomagnified with increasing trophic level. Aquatic birds are useful bioindicators of many pollutants, including mercury, due to their abundance and position in the food chain. Previous studies have primarily focused on mercury …


Assessing The Use Of Regenerative Agriculture In California Almonds As Climate Change Resilience, Skyler M. Seamons May 2024

Assessing The Use Of Regenerative Agriculture In California Almonds As Climate Change Resilience, Skyler M. Seamons

Master's Projects and Capstones

The agriculture sector is responsible for 10% of the United States’ greenhouse gas emissions. In turn, anthropogenic climate change threatens crops. With its Mediterranean climate, California is the country’s largest agricultural-producing state. Many California crops are at risk due to increasing temperatures and changed precipitation patterns. This paper investigates regenerative farming techniques as a tool to protect California crops from a changing climate. Almonds are used as a case study to analyze the soil management practices, finances, and policies underlying regenerative agriculture in California. A literature review and comparative analysis are used to compare regenerative and conventional soil management practices …


From Pixels To Plants: Remote Sensing Of California Invasive Plants, Kenneth Rangel May 2024

From Pixels To Plants: Remote Sensing Of California Invasive Plants, Kenneth Rangel

Master's Projects and Capstones

Invasive plants cause significant impacts to ecosystems, the economy, and human health. California has experienced significant plant invasions and is well suited to future invasion because of its Mediterranean climate and human disturbance. Eradication or control of invasive plant species requires a detailed understanding of their spatial distribution, which typically involves on the ground surveys that can be expensive or inconsistent. Remote sensing offers a potential alternative or supplement to in-person invasive plant mapping. This study performed a comparative analysis of 41 remote sensing studies that mapped the distribution of California invasive plants. I found that while high spectral resolution …


Techniques And Trials In Pteridophyte Conservation And Cultivation, Jessica Bartel May 2024

Techniques And Trials In Pteridophyte Conservation And Cultivation, Jessica Bartel

Senior Theses and Projects

With the progressive nature of climate change conditions globally over the past century, there has been increasing focus on conservation of all species, but particularly those already endangered. Over 12,000 species of ferns live on Earth, and they do not produce seeds, so an investigation into their spores and how they reach maturity will allow us to preserve more genetic material in the future for these species. As a result, we investigated ex situ conservation and survivability of in vitro cultured gametophytes of within the genus Dryopteridaceae through herbarium sample germination rates across samples representing a wide age range ( …


Phase Equilibria And Heat Capacities For Tetraarylphosphonium-Based Ionic Liquids, Allan Wilson May 2024

Phase Equilibria And Heat Capacities For Tetraarylphosphonium-Based Ionic Liquids, Allan Wilson

Honors Theses

Climate change is one of the most pressing issues facing humanity in the 21st century. A major contributing factor to this problem is the continued use of fossil-fuel based sources of energy. Concentrated solar power (CST) with thermal energy storage (TES) provides a potential opportunity to support this transition away from fossil fuels but suffers from high costs and extended downtimes. Current heat transfer fluids used in these processes often consist of a mixture of alkali metal nitrates with melting points above 200°C. For CST and TES to be viable, a thermally stable, low melting fluid is needed. Ionic liquids …


Which Vole Is Which: Dna-Based Species Identification For Wisconsin’S Three Microtus Species, Madeline Noel Opie May 2024

Which Vole Is Which: Dna-Based Species Identification For Wisconsin’S Three Microtus Species, Madeline Noel Opie

Theses and Dissertations

Accurate species identification is necessary to implement conservation strategies in the wild. When traditional morphology-based species identification is challenging due to phenotypic plasticity, overlapping characteristics, or the species are otherwise cryptic, DNA-based species identification may be more suitable. Of the three species of Microtus in Wisconsin, two are listed as threatened at the state level. Both M. ochrogaster and M. pinetorum have stable population levels at the national level but are along the northern edge of their ranges in Wisconsin. Small and vulnerable populations of M. ochrogaster and M. pinetorum are limited to isolated patches in the southwestern portion of …


Spatial Ecology Of Mule Deer Migrations From Grand Teton National Park And The Teton Range, Justin K. Schwabedissen May 2024

Spatial Ecology Of Mule Deer Migrations From Grand Teton National Park And The Teton Range, Justin K. Schwabedissen

All Graduate Theses and Dissertations, Fall 2023 to Present

The Greater Yellowstone Ecosystem hosts several of the longest, fully intact ungulate migrations remaining in the continental United States. However, expanding development and an increasing human footprint continue to truncate migratory routes. While the endpoints are often a seasonal range on protected lands, these migration corridors frequently cross other jurisdictional boundaries, including large tracts of private or multiple-use lands, with varying levels of protection. Thus, it is critical resource managers understand the dynamics of migratory movements to define population-level corridors and prioritize appropriate conservation strategies. Mule deer in Wyoming have been documented traveling long distances between summer and winter ranges; …


Environmental Factors Associated With Triploid Aspen Occurrence In Intermountain West Landscapes, James A. Walton May 2024

Environmental Factors Associated With Triploid Aspen Occurrence In Intermountain West Landscapes, James A. Walton

All Graduate Theses and Dissertations, Fall 2023 to Present

Polyploidy is common among plants and can contribute to physiological and morphological differences, altering how plants respond to environmental changes, promoting genetic diversification and even species radiation. Quaking aspen (Populus tremuloides), a keystone species associated with high plant and animal diversity is frequently found in mixed diploid/triploid populations in the Intermountain West. Triploid aspen carries an extra chromosomal copy, whereas the diploid type contains two chromosomal copies. High mortality rates and widespread population declines in aspen are of increasing concern in the Intermountain West, and often ascribed to changing climates and drought stress events. The goal of this …


Do Heat Waves Drive Natural Selection In Damselflies?, Adam Baranyk May 2024

Do Heat Waves Drive Natural Selection In Damselflies?, Adam Baranyk

Biological Sciences Undergraduate Honors Theses

Climate change has led to changes in both mean temperatures and temperature extremes over the recent years. These changes have had differential effects on animals throughout the world. Ectotherms depend on their external environment for thermal regulation, making them especially susceptible to temperature extremes. It is not yet clear whether there is a relationship between physical traits in ectotherms, and survivorship throughout a heat wave. That is, whether or not temperature extremes driven survival selection. In this study, a heat wave was simulated artificially using thermally regulated mesocosms at different temperatures (18°C, 22° C, 26° C, 30° C) with a …


Assessing Equitable Distribution Of The Urban Tree Canopy At The Neighborhood Scale In Greenville, South Carolina., April Riehm May 2024

Assessing Equitable Distribution Of The Urban Tree Canopy At The Neighborhood Scale In Greenville, South Carolina., April Riehm

All Theses

We are living in an era that necessitates adaptation and resilience. The Earth is warming. Our climate has changed (EPA, 2016). Our planet is also rapidly urbanizing. It is predicted that 68% of people will live in cities by 2050. The City of Greenville is a rapidly growing city in South Carolina that has been losing its tree canopy to development(City of Greenville, 2023). The Urban Tree Canopy (UTC) is a community asset that provides many quality-of-life benefits including improved air quality, stormwater management, carbon sequestration, mental and physical well-being, increased mobility and access, aesthetics, a reduction in energy costs, …


Assessing Nordihydroguaiaretic Acid Properties And Its Potential Therapeutic Effect For Glioblastoma, Jose Arturo Guerrero May 2024

Assessing Nordihydroguaiaretic Acid Properties And Its Potential Therapeutic Effect For Glioblastoma, Jose Arturo Guerrero

Open Access Theses & Dissertations

This study employs a combination of theoretical and experimental analysis to spectroscopically investigate the biomechanistic structure relationship and therapeutic effects of the Nordihydroguaiaretic Acid (NDGA) chemical derived from the Larrea Tridentata plant. These relationships are crucial for understanding NDGA's efficacy in disease prevention, treatment, and potential toxicological effects. While the medicinal and antiviral properties of the NDGA have been studied extensively, there remains a gap in optically identifying and reporting its structural changes. The current research successfully reveals evident trends in NDGA's vibrational signatures, particularly highlighting the absence of the Raman feature at 780 〖cm〗^(-1) as indicative of a fully …


Winter Roost Selection Of Eastern Red Bats And Impacts Of Non-Growing Season Prescribed Fire On Foraging Activity Of Forest Roosting Bats In Tennessee, Ashley D. Epstein May 2024

Winter Roost Selection Of Eastern Red Bats And Impacts Of Non-Growing Season Prescribed Fire On Foraging Activity Of Forest Roosting Bats In Tennessee, Ashley D. Epstein

Masters Theses

With an increase in wind energy development and continued deforestation and habitat degradation, eastern red bats (Lasiurus borealis; LABO) and other migratory foliage roosting bats (hoary bat [Lasiurus cinereus; LACI], silver-haired bat [Lasionycteris noctivagans; LANO]) are at risk of severe population declines, potentially leading to the need for protection under the Endangered Species Act. While studies have been done examining the ecology of these species, there is still a lack of research on winter roosting and foraging behaviors. This research aims to fill some of those knowledge gaps by 1) Examining roost use (i.e., trees vs. litter) …


An Analysis Of Pollution In Liverpool, Uk, Luke W. Lawson Apr 2024

An Analysis Of Pollution In Liverpool, Uk, Luke W. Lawson

Honors Theses

Within this experiment the different levels of pollution in areas around Liverpool were tested. These areas were Stanley Park, Lunt Meadows, and Woolton Road. At Stanley Park one of two transects had a geochemical analysis as well as magnetic measurements run to investigate source attribution within the urban environment resulting in data showing high variability in soil properties among the transect. With data supporting evidence of diamagnetic, paramagnetic, and ferromagnetic properties in soil along the same transect. At Lunt Meadows, through the use of XRF for soil samples and nitrate and phosphate testing for water samples, it was found that …


Microplastic Quantification On The Effect Of Endoparasite Communities In Florida Seabirds, Sarah N. Prieto Apr 2024

Microplastic Quantification On The Effect Of Endoparasite Communities In Florida Seabirds, Sarah N. Prieto

All HCAS Student Capstones, Theses, and Dissertations

Microplastics are being studied in a variety of different projects to better understand their impact and threat to wildlife species. Although there is an understanding that microplastics are affecting our wildlife, there are still questions about how coastal seabirds come to ingest them and how the ingestion is altering critical biological processes, such as that for endoparasite communities. This project aims to determine a better understanding of two main objectives: assessment of the presence of secondary ingestion of microplastics in coastal seabirds due to the fish species they prey on and relationship between microplastics and endoparasite communities' structure and state …


Exploring Cation Exchange: Unveiling Its Significance In Biochar And Bioenergetics Applications, Gyanendra Kharel Apr 2024

Exploring Cation Exchange: Unveiling Its Significance In Biochar And Bioenergetics Applications, Gyanendra Kharel

Chemistry & Biochemistry Theses & Dissertations

Cation exchange, a cornerstone of soil chemistry and nutrient cycling, is a fundamental chemical process that occurs in soils, sediments, membranes, and other solid materials. It involves the interchange of positively charged ions, or cations, between a solid matrix and a surrounding solution. This process is crucial in various natural and engineered systems, leading to a range of applications across different fields.

This dissertation presents an extensive investigation into the applications of cation exchange in the fields of biochar and bioenergetics, encompassing three distinct aims. The first aim concentrates on the surface oxygenation of biochar through ozonization, aiming to achieve …


Time Series Modeling To Ascertain Age In Fisheries Management, Kathleen Sue Kirch Apr 2024

Time Series Modeling To Ascertain Age In Fisheries Management, Kathleen Sue Kirch

OES Theses and Dissertations

The ability to assign accurate ages of fish is important to fisheries management. Accurate ageing allows for the most reliable age-based models to be used to support sustainability and maximize economic benefit. Structures used to age include bones, scales, and most commonly ear bones (otoliths). Assigning age relies on validating putative annual marks by evaluating accretional material laid down in patterns in fish otoliths, typically by marginal increment analysis. These patterns often take the shape of a sawtooth wave with an abrupt drop in accretion yearly to form an annual band and are typically validated qualitatively. Researchers have shown keen …


Ecology And Conservation Of Diamondback Terrapins In Virginia, Cypress Ambrose Apr 2024

Ecology And Conservation Of Diamondback Terrapins In Virginia, Cypress Ambrose

Undergraduate Honors Theses

The diamondback terrapin (Malaclemys terrapin) is the only turtle species native to North America with specific morphological and physiological adaptations to estuarine environments. Along with many other pressures contributing to population declines, terrapins frequently become trapped and drown as bycatch in crab pots used in the commercial and recreational blue crab (Callinectes sapidus) fishery. A wealth of evidence supports the use of inexpensive bycatch reduction devices (BRDs) that can be attached to the entrances of these traps, which leads to a marked decrease in terrapin bycatch while not reducing crab catch dramatically. Virginia is the only …


Use Of Unoccupied Aerial Vehicle (Drones) Based Remote Sensing To Model Platform Topography And Identify Human-Made Earthen Barriers In Salt Marshes, Joshua J. Ward Mar 2024

Use Of Unoccupied Aerial Vehicle (Drones) Based Remote Sensing To Model Platform Topography And Identify Human-Made Earthen Barriers In Salt Marshes, Joshua J. Ward

Masters Theses

Elevation is a foundational driver of salt marsh morphology. Elevation governs inundation and hydrological patterns, vegetation distribution, and soil health. Anthropogenic impacts at grand scales (e.g., rising sea levels) and local scales (e.g., infrastructure) have altered the elevation of the salt marsh surface, changing the topography and morphology of these ecosystems. This study establishes and assesses means to document and analyze these impacts using Unoccupied Aerial Vehicle (UAV) based remote sensing to model platform topography. This thesis’s first and primary study presents and compares methods of producing high-resolution digital terrain models (DTMs) with UAV-based Digital Aerial Photogrammetry (DAP) and Light …


Automated Tree Mortality Detection Using Ubiquitously Available Public Data, Michael T. Huggins Mar 2024

Automated Tree Mortality Detection Using Ubiquitously Available Public Data, Michael T. Huggins

Master's Theses

Understanding the dynamic interplay between fire severity, topography, and tree mortality, is crucial for predicting future forest dynamics and enhancing resilience against climate change-induced wildfire regimes. This thesis develops a multi-sensor approach for automated estimation of tree mortality, then applies it to examine trends in tree mortality over a six-year period across a fire affected study site in the Trinity River basin in Northern California. The Random Forest model uses publicly available USGS 3D Elevation Program Lidar (3DEP) and NAIP imagery as inputs and is likely to be easily adaptable to other landscapes. The model had a Receiver Operating Characteristic …


Supply Is Not Limulus: Research Review Of Horseshoe Crab Conservation In The Face Of Intense Pharmaceutical Demand, Zoya Galeev Mar 2024

Supply Is Not Limulus: Research Review Of Horseshoe Crab Conservation In The Face Of Intense Pharmaceutical Demand, Zoya Galeev

University Honors Theses

Horseshoe crabs are being used by the pharmaceutical industry to conduct endotoxin tests using LAL derived from the organism’s blood to ensure safe medical practice. Their annual collection and bleeding, while not always leading to mortality, affects horseshoe crab behavior and health. This research seeks to understand how the American horseshoe crab, L. polyphemus, is being used by pharmaceutical agencies and the implications that their harvesting has on the industry and the conservation of the species. Studies were collected from the past decade across two databases, Web of Science (WOS) and PubMed, to assess present conservation techniques to reduce …


Towards Sociobiogeochemistry: Critical Perspectives On Anthropogenic Alterations To Soil Nitrogen Chemistry Via U.S. Urban And Suburban Development, Christopher D. Ryan Feb 2024

Towards Sociobiogeochemistry: Critical Perspectives On Anthropogenic Alterations To Soil Nitrogen Chemistry Via U.S. Urban And Suburban Development, Christopher D. Ryan

Dissertations, Theses, and Capstone Projects

The ecological impacts of changes to land use are relevant to concerns about climate change, eutrophication of waterbodies, and reductions in biodiversity. As a foundational component of ecosystem functioning, changes to soil biogeochemistry have significant effects on overall ecosystem health. With cities continuing to grow and develop in extent, the impacts of urbanization and suburbanization on soils are of particular concern. Despite a wide range of natural climatic and geologic conditions, several factors have driven similar patterns of land transformation and management across the United States. In particular, federal initiatives including the Home Owners Loan Corporation, the Federal Housing Administration, …


Literature Review Nature-Based Art Therapy Exploring Connections And Relationships, Janell Lopez-Curtis Jan 2024

Literature Review Nature-Based Art Therapy Exploring Connections And Relationships, Janell Lopez-Curtis

Expressive Therapies Capstone Theses

Art therapy is a modality used in clinical psychotherapy. It is supported through both quantitative and qualitative research. Branching out from art therapy is nature-based art therapy. This branch of expressive therapies holds the potential to be beneficial as art therapy due to the interconnected access to the scientific fields of ecology, ecopsychology, art therapy, expressive therapies, and other nature-based therapeutic activities; this includes intersectionality in ecological theories such as ecofeminism and deep ecology as well. Through an exploration of literature, this paper will provide definitions and theory-based support through reviewing clinical psychotherapy, evidence-based practices, and art therapy theories. The …


Policy Recommendations For Tire Additive 6ppd And Its Derivative 6ppd-Q, Ashley E. King Jan 2024

Policy Recommendations For Tire Additive 6ppd And Its Derivative 6ppd-Q, Ashley E. King

Dissertations, Theses, and Masters Projects

Around 3.1 billion tires are produced around the world annually1. The antioxidant additive, 6PPD (i.e., N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine) is widely employed in passenger and commercial vehicle tires at 0.4-2% by mass to impede tire degradation2. Antioxidants are intended to migrate to tire surfaces and form protective films to prevent rubber oxidation. 6PPD is designed to react with oxidant species like ozone, intentionally forming chemical transformation products that can then escape from the tire and into the environment. 6PPD-Q (i.e., 2-anilino-5-[(4-methylpentan-2-yl)amino]cyclohexa-2,5-diene-1,4-dione) is one such transformation product.

After release and disbursement in the environment, 6PPD-Q is bioavailable to aquatic animals and mammals and acute …


Factors Associated With Acoustic Bat Presence During Spring Emergence In The Appalachian Mountains Of Western Virginia, Emily Kirk Pody Jan 2024

Factors Associated With Acoustic Bat Presence During Spring Emergence In The Appalachian Mountains Of Western Virginia, Emily Kirk Pody

Theses, Dissertations and Capstones

Studies of threats that bats face during hibernation have increased in response to white-nose syndrome (WNS), a fungal disease that has ravaged North American bat populations. However, impacts of WNS on bat ecology during spring emergence, when bats are potentially recovering from infection and allocating resources for reproduction, is relatively understudied. As more bat species become listed at the federal and state level, the need to understand the factors associated with spring emergence is critical for improving conservation guidelines and habitat management practices. Acoustic monitoring is an efficient method for monitoring bat presence for prolonged periods of time, giving biologists …


A Road Map For Place Based Collaboration For Conflict Reduction, Joseph L. Zecher Jan 2024

A Road Map For Place Based Collaboration For Conflict Reduction, Joseph L. Zecher

Undergraduate Theses, Professional Papers, and Capstone Artifacts

No abstract provided.


Fire Severity Mediates Marten And Fisher Occurrence: Impacts Of The Dixie Fire On A Carnivore Community, Christopher James Collier Jan 2024

Fire Severity Mediates Marten And Fisher Occurrence: Impacts Of The Dixie Fire On A Carnivore Community, Christopher James Collier

Cal Poly Humboldt theses and projects

The consumption of an astounding one million acres resulted from California’s largest single fire to date, the 2021 Dixie Fire. The social and economic losses associated with the fire were immediately apparent, but the effects on wildlife remained unknown. While previous research has suggested mixed or low severity fire may be beneficial to certain wildlife species, the responses to megafires are poorly understood for many carnivores. To better understand these responses to severe fire, I used a random sampling design stratified by burn severity to survey in and around the Dixie Fire footprint using baited camera stations. This allowed me …


Factors That Influence Small Mammal Long Bone Morphology: An Analysis Of The Femora, Tibiae, And Humeri Of The Eastern Gray Squirrel (Sciurus Carolinensis), Tyler Everette Blake Jan 2024

Factors That Influence Small Mammal Long Bone Morphology: An Analysis Of The Femora, Tibiae, And Humeri Of The Eastern Gray Squirrel (Sciurus Carolinensis), Tyler Everette Blake

Theses, Dissertations and Capstones

The goal of this study is to examine the effect of urbanization and latitude on bone morphology, specifically limb length and bone density among gray squirrels endemic to the eastern United States. This study’s hypotheses are as follows: gray squirrels occupying lower latitudes will have larger body sizes and longer limbs relative to body size than those at higher latitudes following Bergmann’s and Allen’s rules. Further, squirrels in urban habitats will have greater bone density than those in rural habitats. Results show moderate correlation between body mass and respective proxies and latitude following Bergmann’s rule. Weak correlations were found between …


The Comparison Of Different Wetland Fish Assemblages Over Time, Robert Edward Adelstein Jan 2024

The Comparison Of Different Wetland Fish Assemblages Over Time, Robert Edward Adelstein

Theses, Dissertations and Capstones

Wetlands provide essential ecosystem services. Historically, we have drained and filled 73% of wetlands for agricultural use throughout the United States from the 1780s to the 1980s (Dahl, 1990). A nationwide focus on restoring wetlands has since occurred. Literature on restored/mitigated wetlands is rife with examples that do and do not support the same ecosystem services as natural wetlands (Langston, 1997; Meil, 2014). Restoration of wetlands occurred at the Green Bottom Wildlife Management Area (GBWMA) over several decades. Various sections of the wetland were classified by age, water depth, and vegetation. One hypothesis was that differences in fish assemblage would …


The Hutton Project: Long-Term Agricultural Impacts On Soil Loss And Carbon Dynamics In Eastern South Dakota, Eli Halverson Jan 2024

The Hutton Project: Long-Term Agricultural Impacts On Soil Loss And Carbon Dynamics In Eastern South Dakota, Eli Halverson

Electronic Theses and Dissertations

Long-term and intensified agricultural land management has resulted in increased rates of soil erosion and has altered much of the carbon cycle at regional and global scales. Anthropogenic degradation of soil resources is a barrier to sustainable production, soil functioning, and ecosystem services. It is difficult to quantify the scope of pedogenic changes due to the lack of legacy data and short temporal scales. This study utilized decades to century-old soil information to quantify historical soil erosion losses and changes in soil carbon pools of eastern South Dakota soils. The results show that soils in the region have been significantly …