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Rooting For The Home Team: Arbuscular Mycorrhizas And Root Traits In Native And Invasive Woody Shrubs, Alexander Ebert

Dissertations - ALL

Exotic species invasions present a global issue that is expected to worsen with the extreme conditions brought about by global climate change and anthropogenic disturbance. Invasive plant species in particular exhibit ecological, economic, and cultural effects on contemporary issues such as biodiversity, ecosystem processes and global food security. Understanding the factors governing both the invasion process and the species that become invasive are important tools for lessening the impacts of plant invasion, as well as preventing future invasions. This dissertation focuses on belowground aspects of these invasive species, including linking arbuscular mycorrhizal fungi (AMF) to invader growth responses, investigating the …

Unraveling Population Heterogeneity Using Single-Cell Analysis, Wenjun Kong

Arts & Sciences Graduate Student Theses and Dissertations

The human body contains approximately 100 trillion cells, encompassing distinct cell types that serve diverse functions. Understanding cell population heterogeneity is vital for uncovering different biological functions and mechanisms. In addition, cells at transition during continual processes, such as development, reprogramming, and disease, are essential for painting the entire blueprint and highlighting critical stages of the progression trajectory. For instance, cell fate engineering holds much promise for generating clinically valuable cell types from mature somatic cells. Nonetheless, current reprogramming protocols are inefficient, and charting the changes in cell identity during such processes can help design strategies to mitigate the off-target …

Overcoming Genetic Heterogeneity In Glioblastoma By Targeting Transcriptional Dependencies, Tatenda Mahlokozera

Arts & Sciences Graduate Student Theses and Dissertations

Glioblastoma (GBM) is the most common intrinsic central nervous system malignancy in adults, accounting for approximately 45% of such cancers. Despite advances in chemo- and radiotherapeutic approaches for various malignancies over the past decade, GBM remains an incurable disease with a dismal prognosis. Even after treatment with the current standard of care, which consists of maximal safe surgical resection, radiotherapy, and both concomitant and adjuvant chemotherapy with temozolomide, median survival is only approximately 17 months. Both treatment failure and difficulties in developing novel targeted therapies for GBM have partly been attributed to the molecular and cellular inter- and intra-tumoral heterogeneity …

Tertiary Lymphoid Tissue In The Urinary Bladder Of Aging Mice And Women, Marianne Morris Ligon

Arts & Sciences Graduate Student Theses and Dissertations

Urinary tract infections (UTIs) are the most common infection of women, affecting roughly half of all women during their lifetime. UTIs frequently recur within 6 months to 1 year of the initial infection to cause recurrent UTIs (rUTIs). Repeated treatment of rUTIs with antibiotics may lead to antibiotic resistance, disruption of the microbiota, and adverse effects of the drugs. To avoid excess antibiotic use, there is an urgent need to understand the mechanisms of host defense against infection to identify new targets for UTI treatment and prophylaxis in women with rUTIs. Postmenopausal and older women have the highest risk of …

Disuse-Driven Plasticity In The Human Brain, Dillan James Newbold

Arts & Sciences Graduate Student Theses and Dissertations

Brain circuits are shaped and maintained by active use. We blocked use of motor circuits in three adult participants by constraining the dominant upper extremity in a cast for two weeks, causing loss of strength and fine motor function. Daily resting-state functional magnetic resonance imaging (rs-fMRI) collected for 42-64 days before, during and after casting revealed two sets of changes in brain function. First, large, spontaneous pulses of activity occurred in the disused motor circuits. Pulses showed a consistent pattern of propagation through the disused circuits— occurring earliest in the dorsal anterior cingulate cortex (dACC) and supplementary motor area (SMA), …

Evaluating Threats To The Water Quality Of Little Buffalo Creek And Sarver Run Through Water Quality Analysis And Backpack Electrofishing Surveys, Riley Williams

Electronic Theses and Dissertations

Currently, 64.8% and 52.2% of Little Buffalo Creek and Sarver Run stream kilometers are impaired, respectively. Impairment sources to Little Buffalo Creek include agriculture, riparian deforestation, on-site wastewater, and urban runoff. Impairment sources to Sarver Run are unknown. Our goal was to understand sources of impairment through water quality analysis and fish surveys. Water samples were collected monthly and analyzed for cation and anion concentrations. Mass ratio analysis comparing Br/SO₄ and Mg/Li, Ca/Mg and Ca/Sr, Mg/Na and SO₄/Cl, and SO_4/Cl and Mg/Li suggests that mine drainage and conventional oil and gas may be impacting water …

A Review Of Current Methods In Avian Dietary Analysis And Their Integrated Application To Characterize The Trophic Niche Of Louisiana Waterthrush (Parkesia Motacilla)., Brandon Hoenig

Electronic Theses and Dissertations

Characterizing a species’ dietary composition presents an avenue to understand many facets of its ecological niche and can provide essential information for the species’ long-term conservation. To date, the vast majority of diet studies have relied on direct identification of prey during foraging observations or from diet samples to characterize the dietary habits of birds. However, advancements in laboratory-based approaches have revolutionized the field of trophic ecology by allowing researchers to indirectly infer dietary habits with higher resolution across greater time scales. Here, I apply two of these laboratory-based techniques, namely DNA metabarcoding and stable isotope analysis, to characterize the …

Pre-Pulse Inhibition In Mutated Mice: Studying Compromised Microglial Cells To Discover New Genetic Connections To Autism, Bailey R. Kramarik

Senior Honors Projects, 2020-current

Microglial cells “play a pivotal role in refining neural networks during early critical periods” (Gabriele & Gray, 2020, p. 1). A disturbance in the functioning of these microglial cells contribute to specific characteristics of some neurodevelopmental disorders- including autism spectrum disorder. In this study, we used a mouse model to study disruptions in cell activity, as understanding the biological and genetic background of autism spectrum disorder could help us provide better treatment and therapy options to those diagnosed.

The mutated mice in this experiment have microglial cells with “compromised fractalkine signaling” (Gabriele & Gray, 2020, p. 4-5). We studied multimodal …

Sprouting Systems, Abaigeal Aydt, Cassidy Smith

Honors Program: Expanded Learning Clubs

After taking a class at UNL about environmental awareness, two honors students paired up to start a hydroponics club at a local Lincoln school. In reaching out to the LPS director of sustainability, they were paired up with Prescott Elementary School. Over the course of a semester, they developed a club that got a hydroponic grow tower functioning for the school and taught students about nutrition and sustainability. This club is only in its beginning stages, but the impacts that it is making around the school can already be seen.

Physiological Costs Of Total Cholesterol In European Starlings Across An Urban To Rural Gradient, Courtney Linkous

Master of Science in Integrative Biology Theses

Urban areas—characterized by high human densities and associated buildings and impermeable surfaces—are increasing globally and represents a leading threat to wildlife that is drastically altering the natural resources they are accustomed to. Prior studies suggest that living in urban habitats can cause wildlife to show increased cholesterol levels; in biomedical research, elevated cholesterol is linked to disease, but the consequence of elevated cholesterol in wildlife remains unclear. We measured total cholesterol in European starlings (Sturnus vulgaris)—an urban adapted species—across an urban and a rural site. We ask: (1) do urban starlings have elevated cholesterol, (2) does elevated cholesterol …

Pilfering Passerines? Inter-Class Competition: A New Direction In Foraging Ecology, Shannon Gillen

Masters Theses, 2020-current

Life in the epigeal layer below leaf litterfall often goes unexplored. Shrews (Soricidae, 1910) have foraged in this microhabitat for millions of years, carving out an existence in harsh habitats around the world, ranging from the tropics to subarctic boreal tundra. Two shrew species that inhabit the Shenandoah Valley of Virginia, the least shrew (Cryptotis parva) and northern short-tailed shrew (Blarina brevicauda), were the focus of this study. Shrews make epigeal foraging trails while they continually forage for food, and caching is a way to save this food for times of low and sporadic food availability. …

Classification Of Eurasian Watermilfoil (Myriophyllum Spicatum) Using Drone-Enabled Multispectral Imagery Analysis, Colin Brooks, Amanda Grimm, Amy Marcarelli, Nicholas Marion, Robert Shuchman, Michael Sayers

Michigan Tech Publications, Part 1

Remote sensing approaches that could identify species of submerged aquatic vegetation (SAV) and measure their extent in lake littoral zones would greatly enhance SAV study and management, especially if these approaches can provide faster or more accurate results than traditional field methods. Remote sensing with multispectral sensors can provide this capability, but SAV identification with this technology must address the challenges of light extinction in aquatic environments where chlorophyll, dissolved organic carbon, and suspended minerals can affect water clarity and the strength of the sensed light signal. Here, we present an uncrewed aerial system (UAS)-enabled methodology to identify the extent …

Clock-Linked Genes Underlie Seasonal Migratory Timing In A Diurnal Raptor, Christen M. Bossu, Julie A. Heath, Gregory S. Kaltenecker, Barbara Helm, Kristen C. Ruegg

Biology Faculty Publications and Presentations

Seasonal migration is a dynamic natural phenomenon that allows organisms to exploit favourable habitats across the annual cycle. While the morphological, physiological and behavioural changes associated with migratory behaviour are well characterized, the genetic basis of migration and its link to endogenous biological time-keeping pathways are poorly understood. Historically, genome-wide research has focused on genes of large effect, whereas many genes of small effect may work together to regulate complex traits like migratory behaviour. Here, we explicitly relax stringent outlier detection thresholds and, as a result, discover how multiple biological time-keeping genes are important to migratory timing in an iconic …

Gene Expression Analysis Revealed The Activation Of Immune Responses During The Postnatal Development Of The Cerebellum In A Mouse Model Of Niemann-Pick Type C, Sierra Elizabeth Melli

Theses and Dissertations

Niemann-Pick Type C (NPC) is a recessive neurodegenerative lysosomal storage disorder that is caused by autosomal recessive mutations. The mutations result in the inactivation of NPC1 and NPC2 proteins. Inactivation of the NPC1 protein results in the accumulation of cholesterol within the endosomal and lysosomal compartments of cells including Cerebellar Purkinje cells. This accumulation of cholesterol leads to symptoms of dementia, neurodegeneration and potential of early childhood death in cases of early onset. In this study, we analyze the gene expression levels using the RNAseq technique in order to determine whether there is a significant difference between the expression of …

Global Collision-Risk Hotspots Of Marine Traffic And The World’S Largest Fish, The Whale Shark, Freya C. Womersley, Nicolas E. Humphries, Nuno Queiroz, Marisa Vedor, Ivo Da Costa, Miguel Furtado, John P. Tyminski, Katya Abrantes, Gonzalo Araujo, Steffen S. Bach, Adam Barnett, Michael L. Berumen, Sandra Bessudo Lion, Camrin D. Braun, Elizabeth Clingham, Jesse E. M. Cochran, Rafael De La Parra, Stella Diamant, Alistair D. M. Dove, Christine L. Dudgeon, Mark V. Erdmann, Eduardo Espinoza, Richard Fitzpatrick, Jaime González Cano, Jonathan R. Green, Hector M. Guzman, Royale Hardenstine, Abdi Hasan, Fábio H. V. Hazin, Alex R. Hearn, Robert E. Hueter, Mohammed Y. Jaidah, Jessica Labaja, Felipe Ladino, Bruno C. L. Macena, John J. Morris Jr., Bradley M. Norman, Cesar Peñaherrera-Palma, Simon J. Pierce, Lina Maria Quintero, Dení Ramírez-Macías, Samantha D. Reynolds, Anthony J. Richardson, David P. Robinson, Christoph A. Rohner, David R. L. Rowat, Marcus Sheaves, Mahmood Shivji, Abraham B. Sianipar, Gregory B. Skomal, German Soler, Ismail Syakurachman, Simon R. Thorrold, D. Harry Webb, Bradley M. Wetherbee, Timothy D. White, Tyler Clavelle, David A. Kroodsma, Michele Thums, Luciana C. Ferreira, Mark G. Meekan, Lucy M. Arrowsmith, Emily K. Lester, Megan M. Meyers, Lauren R. Peel, Ana M. M. Sequeira, Victor M. Eguiluz, Carlos M. Duarte, David W. Sims

Biology Faculty Articles

Marine traffic is increasing globally yet collisions with endangered megafauna such as whales, sea turtles, and planktivorous sharks go largely undetected or unreported. Collisions leading to mortality can have population-level consequences for endangered species. Hence, identifying simultaneous space use of megafauna and shipping throughout ranges may reveal as-yet-unknown spatial targets requiring conservation. However, global studies tracking megafauna and shipping occurrences are lacking. Here we combine satellite-tracked movements of the whale shark, Rhincodon typus, and vessel activity to show that 92% of sharks’ horizontal space use and nearly 50% of vertical space use overlap with persistent large vessel (>300 …

Ontogenetic Niche Shift As A Driver Of Community Structure And Diversity In Non-Avian Dinosaurs, Katlin M. Schroeder

Biology ETDs

As some of the most charismatic megafauna to ever walk the earth, the physiology, morphology, growth and evolution of non-avian theropods has been studied exhaustively, yet little is understood about their roles in ecosystems as juveniles. For carnivorous megatheropods, which exceed 1,000kg in mass yet hatched from eggs of limited size, the likelihood of utilizing different prey through ontogeny was high, simply by proxy of the immense difference in size between adults and juveniles. We found these ontogenetic niche shifts, evidenced by significantly different dental microwear in Tyrannosaurids, to have excluded dinosaurian mesocarnivores from Mesozoic communities. The few dinosaurian mesocarnivores …

Invasion Of The Northeastern United States By The Southern Pine Beetle, Dendroctonus Frontalis, And The Impacts On Signatures Of Isolation By Distance Assessed Using Mitochondrial Dna, Lora Grace Holman

Honors Theses

The southern pine beetle (SPB) is a small, black beetle that parasitizes pine trees across the United States and Central America. Recently it has been recognized that the range of SPB is not limited to the southern United States, but rather extends northward across the eastern United States, which raises concerns for pine trees that have never encountered the pest before. Using mitochondrial DNA sequences from a section of the cytochrome oxidase I gene and four different measures of genetic distance compared to geographic distance, we tested for evidence of isolation by distance (IBD) among sampled SPB to see whether …

Investigating The Role Of Small Rna Pathways In Arabidopsis Shoot Gravitropism, Julia Lott

Honors Theses

The plant stem grows against the gravitational force, a phenomenon called negative gravitropism. In the model dicotyledonous plant Arabidopsis thaliana, gravity is sensed by starch-filled amyloplasts, which trigger the shoot gravitropic response through the action of a growth hormone called auxin. In the darkness, a group of transcription factors named PHYTOCHROME-INTERACTING FACTORS (PIFs) promote stem negative gravitropism by inhibiting the starch metabolism in the endodermal amyloplasts. Red light promotes starch metabolism and converts amyloplasts into other types of plastids (e.g., chloroplasts) through the red/far-red light photoreceptors—phytochromes. Consequently, red-light-grown seedlings lose starch granules in amyloplasts and exhibit agravitropic growth. However, the …

Developing A Novel Place Preference Assay To Compare Drosophila Species Over Time, Martha M. Brinson

Honors Theses

Across phylogeny, integration of external factors, memory, and internal states of the organism dictate organismal behavior and mechanisms. The underlying genetic components can affect these behaviors such as in genomic changes arising from speciation. In this thesis, a new place preference assay was evaluated in the analysis and investigation of two species of Drosophila flies (D. melanogaster and D. simulans) to measure similarities and differences and their attraction to two different food substrates. Sleep and circadian measurements were also recorded during experimentation. The Drosophila Activity Monitor 5M (DAM5M) System and Sleep Circadian Analysis MATLAB Program (SCAMP) analysis were …

Cache Like A Squirrel: Effects Of Long Term Storage On Crude Fat Content Of Q. Palustris And Q. Alba Acorns, Cheyenne T. Villarosa, Sabrina Volponi, Timothy A. Kreps, Tamara L. Johnstone-Yellin

Honors Projects

Quercus palustris and Quercus alba acorns are a primary component in many wild animal diets, particularly during preparation for winter. As such, they provide a natural, easily gathered food staple for wildlife recovering in rehabilitation facilities. We examined whether collection and temperature-controlled storage methods differentially affect the nutritional deterioration of crude fat in acorns to assess both caching by wildlife and to provide recommendations to rehabilitators. We collected acorns from Q. palustris in 2020 (N=8) and Q. alba in 2017 (N=11) in Bridgewater, VA, USA. Acorns were dried for 7 days using a fan or for 30 minutes in an …

Detection And Occurrence Of Nerodia Harteri (Serpentes: Colubridae) In An Upper Portion Of The Brazos River Watershed, Jessica Yates

Electronic Theses and Dissertations

Semiaquatic snakes are disproportionately impacted by habitat alteration adjacent to wetlands because of their reliance on both terrestrial and aquatic habitats. Brazos River Watersnakes, Nerodia harteri, are endemic natricines with one of the most restricted geographic ranges in North America. I quantified detection and site occupancy probabilities of N. harteri and its sympatric congeners (N. erythrogaster and N. rhombifer), as well as microhabitat selection within the Nerodia community. Within occupied transects, search effort was positively correlated with detecting N. harteri, whereas environmental and/or habitat variables were better predictors for detecting the sympatric congeners. Microhabitat selection between …

Detecting Potentially Neurotoxic Pseudo-Nitzschia Species In The Grand Strand Area, Chesney Price

Honors Theses

Pseudo-nitzschia is a globally distributed diatom genus which contains 26 neurotoxin (domoic-acid) producing species. In shallow coastal waters these diatoms are associated with both the development of harmful algal blooms and the bio-accumulation of toxins in shellfish that can impact human health. Pilot data recovered in 2018 indicated the presence of multiple species of Pseudo-nitzschia, including domoic-acid producing taxa. We hypothesize that we will recover a similar species diversity using multiple sampling dates during the summer of 2021. Environmental DNA (eDNA) samples taken from the public shellfish harvesting area waters at Huntington Beach State Park (SC) over a two month …

Integrating Radio Telemetry And Accelerometry To Evaluate The Scale-Dependent Effects Of Roadways On The Movement Patterns Of Timber Rattlesnakes (Crotalus Horridus), Anna F. Tipton

Biology Theses

Roadways are among the most widespread and disruptive anthropogenic land use features that influence the behavior and movement of wildlife. Negative impacts such as vehicle-induced mortality, habitat destruction and fragmentation, and the creation of barriers to movement have been well documented across taxa, but the fine-scale behavioral impact of roadways on smaller, cryptic species has yet to be directly examined. Using a novel integration of radio telemetry and tri-axial accelerometry, we evaluated the movement response of Timber Rattlesnakes (Crotalus horridus) to roadways in central Georgia. We quantified individual C. horridus movement and space use with both radio telemetry …

An Economical Source For Peroxidase: Maize Cobs, Hathama Razooki Hasan, Ali Waleed Al- Ani

Karbala International Journal of Modern Science

According to the current situation of peroxidase (POD), the relevant studies on this enzyme indicated its importance as a tool in clinical biochemistry and different industrial fields. Most of these studies used the fruits and vegetables as source of this enzyme. So that in order to couple the growing requirements for POD with the recent demands for reduc-ing disposal volume by recycling the plant waste, the aim of the present study was to extract POD through management of municipal bio-waste of Iraqi maize species. A simple, green and economical method was used to extract this enzyme. Our results revealed that …

Efficient Removal Of Common Organic Pollutants From Water By Zn-Doped Tio2 Nanoparticles With Different Applications, Khaled Elgendy, Ibrahim Elmehasseb, Saleh Kandil

Karbala International Journal of Modern Science

Water purification via adsorption without energy consumption was considered a green process. Zn-doped TiO2 nanoparticles were fabricated by the Sol-gel method and characterized by different analysis techniques. Zinc doping of TiO2 increases the surface area to 26.7m2g-1 with adsorption results, 75.1%, 71.1%, and 68.2% for methylene blue, ofloxacin, and SLS, respectively. Variable affecting factors on adsorption have been studied. The adsorption behavior fitted with Langmuir and Freundlich equations than Temkin isotherm, indicating the preferred heterogeneous adsorption at equivalent adsorbent sites. The application of nanoparticles in many synthetic specimens of pollutants gave excellent removal results, which exceeded 75% of detoxification.

Effect Of Mycorrhizae Inoculation On The Growth And Success Of Three Taxodium Distichum Hybrids In Saline - Impacted Coastal Soils, Elif Ilhan

Electronic Theses and Dissertations

In 2008, Galveston Island was severely impacted by Hurricane Ike, resulting in high salt deposition in the soil and groundwater. This caused a loss of many native plant species. A study was initiated to determine effective ways to promote the growth conditions of three bald cypress genotypes (Taxodium distichum var distichum and Taxodium distichum var mexicanum crosses) in salt-affected soils. The treatments applied were mycorrhizae inoculation, fertilizer application, and a combination of mycorrhizae inoculation and fertilizer application. A total of sixty (60) trees planted in plots of three rows and divided into five randomized replication blocks of four treatments …

Impacts Of Doliolids On The Marine Microbial Community Off The Oregon Coast, Melissa Steinman, Anne Thompson, Kelly Sutherland

Student Research Symposium

Marine microbes drive global biogeochemical cycling and are critical to sequestering carbon dioxide from the atmosphere to the ocean. Predation on marine microbes by viruses and single-celled microbes is well documented, yet models of microbial mortality with these sources do not account for observations of microbial death. We examined how an understudied group of animals, pelagic tunicates, could feed on marine microbes using an internal mucous mesh. One group of pelagic tunicates, the doliolids, have the potential to reshape marine microbial communities when they bloom. We sampled doliolids off the Oregon Coast and characterized the diversity, taxonomy, and relative abundance …

B-Vitamins Influence The Consumption Of Macronutrients In Honey Bees, Walaa Ahmed Elsayeh, Chelsea N. Cook, Geraldine A. Wright

Biological Sciences Faculty Research and Publications

Insects require dietary sources of B-vitamins, but relatively little is known about whether they regulate B-vitamin intake in the same way they regulate other nutrients. Honey bees meet their B-vitamin requirements mainly from the pollen they collect. Employing the geometric framework for nutrition, we found that honey bees actively regulate their vitamin intake following Bertrand’s rule. We fed bees with a diet of essential amino acids (EAAs) and carbohydrate (C) to identify how the addition of B-vitamins affected the regulation of these macronutrients. In our experiments, honey bees preferred vitamins in concentrations comparable to those found in honey bee food …

Four In One: Cryptic Diversity In Geoffroy’S Side-Necked Turtle Phrynops Geoffroanus (Schweigger 1812) (Testudines: Pleurodira: Chelidae) In Brazil, V. T. De Carvalho, R. C. Vogt, R. R. Rojas, M. D. S. Nunes, R. De Fraga, R. W. Ávila, A. G J Rhodin, R. A. Mittermeier, Tomas Hrbek, I. P. Farias

Biology Faculty Research

Turtles are one of the most threatened groups of vertebrates, with about 60% of species classified at some level of extinction risk. Compounding this extinction crisis are cryptic species and species complexes that are evaluated under a single species epithet but harbor multiple species, each of which needs to be evaluated independently. The Phrynops geoffroanus species group is a classic example. Described first in 1812, it is currently thought to harbor multiple species. To test this hypothesis, we collected mitochondrial and nuclear genomic data, morphometric data, and distribution and associated biome information. We applied statistically rigorous species delimitation analyses, taxonomic …

Effects Of Glucocorticoids Upon Pro-Inflammatory Responses To Acute Sleep Fragmentation, Hunter Weaver

Masters Theses & Specialist Projects

Sleep loss is a common problem in humans who suffer from obstructive sleep apnea. Sleep aids in the regulation of immune responses, some of which induce inflammatory responses. Cytokines regulate the inflammatory process and are released in response to sleep fragmentation (SF) in mice. Glucocorticoids are hormones that are released from the adrenal cortices during a stress response and are considered to be anti-inflammatory and immunosuppressive at high doses but may stimulate immune function on an acute level. The first hypothesis tested was that normal physiological expression of glucocorticoids (Sham) will display increased IL-1β and TNFα expression levels, while high …