Digital Commons Network^™

The Interactions Between Drought Tolerant Corn Hybrids And Plant Water-Stress On Weeds And Their Host Capability For Spider Mites, Mercy Adhiambo Odemba

All Graduate Theses and Dissertations, Fall 2023 to Present

With climate change, it is predicted that more frequent high temperatures and drought severity will lead to an increase in damage caused by pests that thrive under these conditions. Spider mite outbreaks, for example, are associated with plant waterstress and there is evidence that some weeds are more resilient and adapted to drought than some crops, leading to major concerns for the management of these two pest types. Weeds directly compete with crops for limited resources, but what is unclear is which weeds harbor spider mites and whether they exacerbate the impact of spider mites on corn crops under water-stressed …

Screen For Beneficial Genetic And Chemical Modifiers In Drosophila Models Of Als And Traumatic Brain Injury, Will Bonderer

Biological Sciences Theses and Dissertations

The underlying molecular processes of aberrant protein expression in neurodegeneration are intricate and multifaceted, with ribosome-associated quality control (RQC) emerging as a promising avenue of exploration. Ribosome-associated quality control is integral to cellular function. Its evolutionarily conserved pathway encompasses a network of mechanisms designed to ensure the fidelity of protein synthesis, folding, and degradation within the cells of all eukaryotes. The ribosome, central to protein synthesis, plays a pivotal role in this quality control network, and its malfunction can lead to the accumulation of misfolded or aberrant proteins. In the context of neurodegenerative disorders, this dysfunction can have dire consequences. …

Measuring The Effects Of Selenium Exposure On Batrachochytrium Dendrobatidis (Bd) Growth In Vivo In Larval American Bullfrogs (Rana Catesbeiana)., Taylor Morrison

Honors Thesis

Most amphibians in today’s world are exposed to a variety of environmental stressors. This project’s main objective was to determine any effects of selenium on Batrachochytrium dendrobatidis (Bd) and infection levels in South Dakota amphibians. I selected American bullfrogs (Rana catesbeiana) as they are susceptible to Bd and are found throughout eastern South Dakota. The secondary objective of this project was to measure any impact of Bd and selenium, combined, on growth measures of the frogs. The third objective was to see if survival rates were reduced when amphibians were exposed to Bd and selenium. Tadpoles were collected (n=225) from …

Survey Of The Bolctes From Fish River Nature Preserve, Noah T. Nelson

Honors Theses

Boletes are a special kind of mushroom inside of the Kingdom Fungi that are distinguished from other mushrooms by their uniquely pored hymenium, as opposed to gills. Many boletes are ectomycorrhizal, meaning they are mutualists with vascular plants, and thus beneficial to the overall health of the terrestrial ecosystem. Some are well-known for their edibility and are of economic importance. In the United States 59 genus-level clades comprising 290 operational taxonomic units have been reported. The southeastern US and Gulf Coast regions however are less researched and recorded for their mushroom ecology. In Alabama, only 56 bolete species have been …

Bcl2 Mediated Targeted Drug Delivery For The Treatment Of Kidney Fibrosis And Stomach Cancer, Humayra Afrin

Open Access Theses & Dissertations

Apoptosis, the programmed death of cells, is primarily regulated by a delicate balance between pro-apoptotic and anti-apoptotic signals. The Bcl-2 (B-cell lymphoma 2) family of proteins acts as anti-apoptotic agents, promoting cell survival. Dysregulation of these proteins is a common occurrence in conditions such as cancer and fibrosis, where overexpression of anti-apoptotic members can foster tumor cell survival and fibroblast activation. In this study, our aim was to explore the therapeutic potential of Bcl-2 inhibitors, both as a small molecule (specifically Navitoclax (Navi)), inhibitor and as Bcl-2 siRNA, for targeted treatment. Intravenous administration of Navi often leads to thrombocytopenia, necessitating …

Synthesis Of Neoglycoproteins As Potential Biomarkers For Chagas Disease And Cutaneous Leishmaniasis Caused By Leishmania (Viannia) Braziliensis, Eileni Rodriguez Gil

Open Access Theses & Dissertations

Protozoan parasites are responsible for causing numerous diseases in humans and mammals worldwide. Among them are Chagas disease (CD), caused by the parasite Trypanosoma cruzi (T. cruzi), and tegumentary leishmaniasis (TL), caused by the parasite Leishmania (Viannia). Both diseases coexist in many regions of Latin America, and current hurdles to differentially diagnose them and determine chemotherapy success need to be overcome. CD can be diagnosed by traditional serological tests and polymerase chain reaction (PCR), but disadvantages of these methods are that they may produce false negatives because the antigens used in commercial CD kits are not conserved across all T.cruzi …

Monitoring Selenium Bioaccumulation In False Map Turtles (Graptemys Pseudogeographica), Grant M. Budden

Honors Thesis

Selenium is an element that becomes bioactivated in aquatic environments. Selenium bioaccumulation may threaten a South Dakota state-threatened species, the False Map Turtle (Graptemys pseudogeographica). Invertebrate filter feeder species like zebra mussels (Dreissena polymorpha) uptake selenium via exposure. Previous laboratory work has found that False Map Turtles consume large amounts of zebra mussels throughout the summer, leading to selenium bioaccumulation from selenium transfer from prey to predator. A myriad of adverse effects, like selenosis, reproductive infertility, and death, are associated with high selenium concentrations. Sampling was completed on False Map Turtles in the summer of 2022. …

Ammonium Chemotaxis In Chlamydomonas Reinhardtii, Gabela Nelson

LSU Doctoral Dissertations

Analysis of ammonium chemotaxis in Chlamydomonas reinhardtii is largely hindered, compared to that of phototaxis, despite equal importance on flagellated microalgal physiology. A major contribution of this shortfall is the lack of proper assay method. We developed a simple Petri dish assay method in which light is homogenously exposed while patterns of the cellular migration are tracked with a function of time. Using the method, new findings were revealed. First, this research presented that a strain lacking the eyespot organelle required for light gradient-sensing exhibits similar chemotactic behavior compared to a wild-type strain, suggesting Chlamydomonas sense an ammonium gradient not …

Pulsed Electric Fields Sensitize Methicillin-Resistant Staphylococcus Aureus To Antibacterial Therapies And Stimulate Host Immune Responses, Alexandra E. Chittams-Miles

Biomedical Sciences Theses & Dissertations

This research explores the impact of nanosecond pulsed electric fields (nsPEF) on two fronts: their immune stimulatory effects and their potential as a novel strategy to enhance the sensitivity of Methicillin-resistant Staphylococcus aureus (MRSA) to clinically relevant antibiotics. While pulsed electric fields have been reported to have an immune stimulatory effect, the mechanisms responsible for these effects have yet to be determined.

Our investigation addresses the rising concern of MRSA derived skin and soft tissue infections (SSTIs). Consistent with other publications, we found that nsPEF alone cause modest inactivation of planktonic MRSA. We then investigated the effects of nsPEF in …

Remodeling Anaplastic Thyroid Cancer's Aggressive Profile And Metabolic Signature By Natural Alkaloid Berberine, Tara Elizabeth Jarboe

NYMC Student Theses and Dissertations

Anaplastic thyroid cancer is a rare, fatal cancer with a five-year survival of 4%. Universally diagnosed at stage IV, anaplastic thyroid cancer is characterized by its lack of differentiation, rapid proliferative rate, highly inflammatory tumor microenvironment, and metabolic dysregulation. Refractory to all established therapies, anaplastic thyroid cancer requires a novel therapeutic approach that targets all of these drivers of anaplastic thyroid cancer carcinogenesis. We propose natural alkaloid berberine as a therapeutic with multitarget efficacy to alter mitochondrial metabolism and reprogram anaplastic thyroid cancer’s aggressive phenotype. Our in vitro model uses monocyte cell line U937, anaplastic thyroid cancer cell lines T238 …

Steminism: Analyzing Factors That Improve Retention Of Women In Stem, Kira Carter, Jane Kelley, Jason Vasser-Elong, Rc Patterson

Dissertations

Our co-authored research ‘Steminism: Analyzing Factors That Improve Retention for Women as STEM Majors’ analyzed factors that contributed to the retention of women in science, technology, engineering, and mathematics (STEM) programs at Missouri University of Science & Technology (Missouri S&T). Women make up half of the US population, and while careers in (STEM) are an integral part of the US economy, women are underrepresented in these career fields. The purpose of our dissertation is to address the underrepresentation of women in STEM majors. Our methodology included homogeneous sampling to collect qualitative data. More specifically, we consulted with academic advisors and …

Impairment Of The Glial Phagolysosomal System Drives Prion-Like Propagation Of Huntington’S Disease, Graham Davis

Theses and Dissertations

The ability of glia to tightly regulate neuronal health and homeostasis in the CNS is conserved across species. Yet, despite the ability to degrade protein aggregates, glia are vulnerable to the accumulation of neurotoxic amyloid aggregates during neurodegenerative disease progress, and even exacerbate their spread. A developing narrative highlights glia as a double-edged sword in neurodegenerative diseases: initially capable of dynamically responding to amyloid aggregate-ladened dying neurons but also capable of inducing chronic inflammation and creating seeding-competent amyloid oligomers. Thus, uncovering the mechanisms that allow glia to control aggregate deposition while preventing the neurotoxic effects and seed generation is vital …

Targeting Strategies To Optimize The Therapeutic Potential Of Gold Compounds Against Her2-Positive Breast Cancers, Afruja Ahad

Dissertations, Theses, and Capstone Projects

The overexpression of HER2 accounts for 20-30% of breast cancer tumors and not only serves as a marker for poor predictive clinical outcomes but also as a target for treatment. Antibody-drug conjugates (ADCs) combine the selectivity of monoclonal antibodies (mAbs) with the efficacy of chemotherapeutic drugs to provide targeted treatment without toxicity to normal tissue. Most of the ADCs currently in the clinic for cancer chemotherapy are based on complex organic molecules. In contrast, the conjugation of metallodrugs to mAbs has been overlooked when there is enormous potential in this area with the resurgence of metal-based drugs as prospective cancer …

Methamphetamine-Induced Dna Double-Stranded Breaks: The Impact Of The Dopamine Transporter And Insights Into The Mechanisms Of Dna Damage In Mouse Neuro 2a Cells, Lizette Couto

Dissertations, Theses, and Capstone Projects

Methamphetamine (METH) abuse remains a global health concern, with emerging evidence highlighting its genotoxic potential. In the central nervous system METH enters dopaminergic cells primarily through the dopamine transporter (DAT), which controls the dynamics of dopamine (DA) neurotransmission by driving the reuptake of extracellular DA into the presynaptic neuronal cell. Additional effects of METH on the storage of DA in synaptic vesicles lead to the dysregulated cytosolic accumulation of DA. Previous studies have shown that after METH disrupts intracellular vesicular stores of DA, the excess DA in the cytosol is rapidly oxidized. This generates an abundance of reactive oxygen species …

A Case Of Incipient Budding Speciation In The California Floristic Province, Infraspecific Divergence In Abronia Villosa, Eli J. Allen

Cal Poly Humboldt theses and projects

Physical barriers to gene flow are the traditional evidence for species divergence. Conversely, there has been increasing acknowledgment of speciation in the face of gene flow as an evolutionary process. Budding speciation involves peripheral populations adapting to local ecological conditions, thereby budding off from a widespread progenitor species. Budding speciation is distinguished by ecological divergence and is generally evidenced by asymmetrical range size and nested phylogenetic relationships of sister species. The narrow endemic Abronia villosa var. aurita is adapted to montane sandy washes adjacent to its widespread sister variety, the desert dwelling var. villosa. Here, I tested the hypothesis …

Persistence Of Wastewater-Associated Antibiotic Resistant Bacteria In River Microcosms, Aoife P. Mahaney

Theses and Dissertations

The spread of antibiotic-resistant bacteria (ARB) associated with wastewater is a significant environmental concern, but little is known about the persistence and proliferation of these organisms in receiving water bodies after discharge. To address this knowledge gap, we performed a series of microcosm experiments in which river water was amended with either untreated or treated wastewater, and the abundance of viable ciprofloxacin-, Bactrim-, and erythromycin-resistant bacteria was monitored for 72 hours.

Both types of wastewater amendments increased the initial abundance of ARB compared to microcosms containing only river water. The increase was greatest with untreated wastewater, but that effect decreased …

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 …

Development Of Innovative Flocculation Technologies For Agricultural Water Treatment, Noor Haleem

Electronic Theses and Dissertations

The development of innovative flocculation technologies is essential for addressing the challenges of agricultural water treatment. These technologies play a crucial role in removing contaminants such as suspended solids and nutrients, thereby ensuring safer water for irrigation and livestock consumption. By enhancing water quality and wastewater management, they contribute significantly to environmental sustainability and public health in agricultural communities. This comprehensive thesis extensively explores various dimensions of flocculation, with a focused effort on methodologies and resources aimed at strengthening sustainability and efficiency. A pivotal aspect of the research involves synthesizing cationic starch (CS), a flocculant derived from an underutilized resource, …

Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin

Biology Dissertations

Mycobacteria encompass many pathogenic species known to cause severe disease in humans. A well-known example is Mycobacterium tuberculosis (Mtb), the causative agent of the lung disease tuberculosis, which kills millions of humans worldwide yearly. Pathogenic mycobacteria like Mtb are challenging to treat because of their innate ability to adapt to environmental stress. Their unique cell physiology and conserved stress responses allow them to combat biological insults, regulate growth, and regulate genes involved in stress; all these responses increase tolerance to antibiotics. The current therapies to treat mycobacterial infections are lengthy and, at times, unsuccessful, partly due to antibiotic tolerance. A …

Characterization Of Host Cell Specific Interactions During Spotted Fever Group Rickettsiae Infection, Emerson Towey

Graduate Theses, Dissertations, and Problem Reports

Vector-borne diseases have been increasing over the past few years due to changes in climate and disturbances in the vectors’ natural environment. To mitigate the risks of these diseases, it is necessary to understand pathogen biology and how it interacts with a host to cause disease. Here we focus our attention on the tick-borne pathogen, Rickettsia rickettsii. R. rickettsii is a member of the spotted fever group (SFG) Rickettsiae and is the etiological agent of Rocky Mountain spotted fever (RMSF), a fatal human disease that is lacking an effective vaccine. Members of the bacterial genus Rickettsia are obligate intracellular endoparasites …

Environmental Biology Masters Capstone, Antonio Gonzalez-Pita

Regis University Student Publications (comprehensive collection)

Human wildlife interactions (HWI) pose a complex challenge for wildlife managers. Human encroachment into wildlife habitat and the growing number of outdoor recreationists are increasing the frequency of contact and conflict, especially in regions such as the Front Range of Colorado. Geographic information systems (GIS), which use a combination of remote sensing and environmental survey data, allow for predictive spatial analyses of where human wildlife interactions are likely to occur. I used publicly reported observations of moose to create spatial predictive maps in a species distribution model framework. Slope and elevation were shown to be the strongest predictors of HWI, …

The Role Of Semaphorins In Response To Injury In C. Elegans Neurons, Maria Belen Harreguy Alfonso

Dissertations

When neural tissue is injured by trauma, delicate neuronal processes such as axons and dendrites are prone to lesion damage and often disconnect. The molecular, cellular, and circuit mechanisms that underlie the regrowth and reconnection of these processes and the recovery of behavior are major challenges in the fields of neuroscience, regeneration, and resilience. At the molecular and cellular levels, signaling pathways that mediate neuronal growth cone guidance during development can play a role in neuronal regeneration and recovery from injury. One family of signaling proteins involved in this process comprises the highly conserved semaphorins and their receptors, the plexins. …

Impacts Of Environmental Stressors On Native South Dakota Amphibian Physiology And Survival, Danielle Jean Galvin

Dissertations and Theses

Amphibian populations around the world are declining, with some of the most likely drivers behind these declines including emerging infectious diseases and environmental contaminants. To address major gaps in the current literature, I sought to evaluate the effect of two major environmental stressors on various aspects of amphibian physiology: emerging infectious diseases and environmental contaminants. Emerging infectious diseases of amphibians include fungal, viral, and parasitic pathogens which have expanded in host range, either geographically or in competent host species. Environmental contaminants include chemicals which may be naturally occurring in the environment, or which may be introduced to the environment, often …

Activity Patterns Of Whiptail Lizards (Aspidoscelis) Found In The Northern Chihuahuan Desert, Guillermo Alvarez

Open Access Theses & Dissertations

Traditional lizard pitfall traps were modified to allow organisms to escape, while collecting valuable ecological data. Modified camera traps were capable of detecting the same species as traditional traps in a semi-arid environment, without posing the associated mortality risks. Pitfall-camera traps were used to sample the activity of the Side-blotched Lizard (Uta stansburiana) and the Southwestern Fence Lizard (Sceloporus cowlesi) in an urban wetland during four continuous years. Evaluations on activity pattern and the activity overlap between the two species revealed extensive overlap, with minor but significant seasonal shifts mediating coexistence. Traps were also effective at detecting other reptiles, invertebrates, …

The Role Of The Cholesterol Synthesis Pathway In Primitive Erythropoiesis, Jose Hernandez

Open Access Theses & Dissertations

Erythropoiesis is the process by which new red blood cells (RBCs) are formed and defects in this process can lead to anemia or thalassemia. The GATA1 transcription factor is an established mediator of RBC development. However, the upstream mechanisms that regulate the expression of GATA1 are not completely characterized. Cholesterol is 1 potential upstream mediator of GATA1 expression because previously published studies suggest that defects in cholesterol synthesis disrupt RBC differentiation. Here we characterize RBC development in a zebrafish harboring a single missense mutation in the hmgcs1 gene (Vu57 allele). Hmgcs1 encodes the first enzyme in the cholesterol synthesis pathway …

Human-Bat Interactions In A Disease Emergence Hotspot: Implications For Human Health And Bat Conservation, Reilly Tempest Jackson

Graduate Theses and Dissertations

Bats are an ecologically important taxon that can host zoonotic pathogens. Globally, many bat species are synanthropic and live closely with humans, often roosting in man-made structures. The spatial overlap between humans and bats creates opportunities for human-bat contact, which can lead to human exposure to bat-borne pathogens and conflicts that cause bat mortality. Despite this risk, little is known about the drivers and characteristics of these human-bat interactions in buildings and work is needed to understand this aspect of the wildlife-urban interface. In Chapter I, I present a literature review that identifies the geographic and taxonomic trends in reported …

The Impacts Of Maturation And Experience On Volumetric Neuroplasticity In Solitary And Social Bees, Mallory A. Hagadorn

All Graduate Theses and Dissertations, Fall 2023 to Present

Some animals are incredibly social, living and working together as one cohesive group. Alternatively, many animals are solitary, never living with and rarely interacting with others. A large body of biological research has focused on understanding the role that brains play in promoting these behavioral differences across species. Even so, it remains unclear why some brains facilitate social behavior while others do not. My dissertation aims to advance our understanding of this concept by characterizing bees’ brains and how they change over a lifetime. Bees are beneficial for investigating relationships between the brain and social behavior because some species are …

Development Of Synthetic Glycobiomarkers For The Follow-Up Of Chagas Disease Chemotherapy And Serological And Molecular Assays For Evaluation Of Trypanosoma Cruzi Infections In The U.S-Mexico Border, Igor L. Estevao

Open Access Theses & Dissertations

Chagas disease (CD), caused by the protozoan parasite Trypanosoma cruzi, affects 7-8 million people worldwide. Lately, the disease has been spread to nonendemic countries and regions, like the U.S. and Europe. The disease can be divided into two phases: the acute and chronic phases, which continue for years or even decades. There are two available drugs for CD treatment: benznidazole (BNZ) and nifurtimox (NFX). These drugs are highly effective in the acute phase but less efficient in the chronic stage. Other limitations of these drugs are their toxicity, leading to serious adverse events and premature treatment termination. Newer clinical trial …

Proteomic Analysis Reveals Fkbp51 And Fkbp52 Interactors Implicated In Androgen Receptor-Mediated Castration Resistant Prostate Cancer, Olga Soto

Open Access Theses & Dissertations

Aberrant signaling mechanisms by the Androgen Receptor (AR) are attributed as the main culprits for the initiation and progression of prostate cancer (PCa). Due to its dependence on androgens, research efforts have focused on developing strategies to directly target androgen-mediated receptor activity. However, given the recurrence and treatment resistance of PCa despite androgen targeted therapies, recent efforts have shifted to find novel targets against the disease. These efforts include further revealing the molecular components and their mechanisms underlying AR signaling in both normal and disease physiological settings. Hence, our lab's work is focused on characterizing and targeting molecular chaperones that …

Repositioning Propranolol To Block Mitogenic Signaling In Breast Cancer, Alexa Noel Montoya

Open Access Theses & Dissertations

Breast cancer is the second most diagnosed cancer among women and is about 30% of all new cases of female cancers each year. It is projected that 1 in 8 every U.S. woman (about 13%) develop invasive breast cancer over the course of her lifetime. While advances in cancer research have made it possible to elucidate several breast cancer genomic subtypes, and develop new novel therapies, many of these agents are associated with significant toxicity, as well as high costs. A retrospective cross-sectional study of 404 breast cancer patients was performed to determine the effect of β-blocker usage on tumor …