Life Sciences Commons^™

Analysis Of Argonaute-Small Rna-Transcription Factor Circuits Controlling Leaf Development, John Steen Hoyer

Arts & Sciences Electronic Theses and Dissertations

Experimental studies of plant development have yielded many insights into gene regulation, revealing interactions between core transcriptional and post-transcriptional regulatory pathways present in all land plants. This work describes a direct connection between the three main small RNA-transcription factor circuits controlling leaf shape dynamics in the reference plant Arabidopsis thaliana. We used a high-throughput yeast 1-hybrid platform to identify factors directly binding the promoter of the highly specialized ARGONAUTE7 silencing factor. Two groups of developmentally significant microRNA-targeted transcription factors were the clearest hits from these screens, but transgenic complementation analysis indicated that their binding sites make only a small contribution …

Binding Affinity And Specificity Of Sh2 Domain Interactions In Receptor Tyrosine Kinase Signaling Networks, Tom Ronan

McKelvey School of Engineering Theses & Dissertations

Receptor tyrosine kinase (RTK) signaling mechanisms play a central role in intracellular signaling and control development of multicellular organisms, cell growth, cell migration, and programmed cell death. Dysregulation of these signaling mechanisms results in defects of development and diseases such as cancer. Control of this network relies on the specificity and selectivity of Src Homology 2 (SH2) domain interactions with phosphorylated target peptides. In this work, we review and identify the limitations of current quantitative understanding of SH2 domain interactions, and identify severe limitations in accuracy and availability of SH2 domain interaction data. We propose a framework to address some …

Effect Of Metal Ion Substitution On Electrochemical Properties Of Cobalt Oxide For Energy Applications, Dalal Alqahtani

Electronic Theses & Dissertations

Metal oxides are being used for various applications, such as batteries, supercapacitors, and catalysts. This research is mainly to produce high-performance energy storage devices capable of working at high temperatures and causing no pollution in the environment. To this end, the effect of metal ion substitution on the electrochemical properties of Co₃O₄ for energy applications was studied. Different metal oxides, such as FeCo₂O₄, MnCo₂O₄, Co₃O₄, NiCo₂O₄, CuCo₂O_4, and ZnCo₂O₄, were synthesized using a hydrothermal …

Characterization Of Structural Dynamics Of The Human Head Using Magnetic Resonance Elastography, Andrew Arun Badachhape

McKelvey School of Engineering Theses & Dissertations

In traumatic brain injury (TBI), the skull-brain interface, composed of three meningeal layers: the dura mater, arachnoid mater, and pia mater, along with cerebrospinal fluid (CSF) between the layers, plays a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is a noninvasive imaging modality capable of providing in vivo estimates of tissue motion and material properties. The objective of this work is to augment human and phantom MRE studies to better characterize the mechanical contributions of the skull-brain interface to improve the parameterization and validation of computational models of TBI. Three specific aims …

Identification Of Prognostic Cancer Biomarkers Through The Application Of Rna-Seq Technologies And Bioinformatics, Nathan Wong

McKelvey School of Engineering Theses & Dissertations

MicroRNAs (miRNAs) are short single-stranded RNAs that function as the guide sequence of the post-transcriptional regulatory process known as the RNA-induced silencing complex (RISC), which targets mRNA sequences for degradation through complementary binding to the guide miRNA. Changes in miRNA expression have been reported as correlated with numerous biological processes, including embryonic development, cellular differentiation, and disease manifestation. In the latter case, dysregulation has been observed in response to infection by human papillomavirus (HPV), which has also been established as both oncogenic in cervical cancers and oropharyngeal cancers and favorable for overall patient survival after tumor formation. The identification of …

Extrinsic And Intrinsic Control Of Integrative Processes In Neural Systems, Anirban Nandi

McKelvey School of Engineering Theses & Dissertations

At the simplest dynamical level, neurons can be understood as integrators. That is, neurons accumulate excitation from afferent neurons until, eventually, a threshold is reached and they produce a spike. Here, we consider the control of integrative processes in neural circuits in two contexts. First, we consider the problem of extrinsic neurocontrol, or modulating the spiking activity of neural circuits using stimulation, as is desired in a wide range of neural engineering applications. From a control-theoretic standpoint, such a problem presents several interesting nuances, including discontinuity in the dynamics due to the spiking process, and the technological limitations associated with …

Characterizing Anisotropy In Fibrous Soft Materials By Mr Elastography Of Slow And Fast Shear Waves, John Larson Schmidt

McKelvey School of Engineering Theses & Dissertations

The general objective of this work was to develop experimental methods based on magnetic resonance elastography (MRE) to characterize fibrous soft materials. Mathematical models of tissue biomechanics capable of predicting injury, such as traumatic brain injury (TBI), are of great interest and potential. However, the accuracy of predictions from such models depends on accuracy of the underlying material parameters. This dissertation describes work toward three aims. First, experimental methods were designed to characterize fibrous materials based on a transversely isotropic material model. Second, these methods are applied to characterize the anisotropic properties of white matter brain tissue ex vivo. Third, …

Influenza A Virus Genomic Reassortment And Packaging, Graham Devin Williams

Arts & Sciences Electronic Theses and Dissertations

Influenza A viruses (IAV) are a major human and environmental pathogen. IAV successfully infects a diverse host range and adaptation of new viral strains to humans may cause pandemic events with high morbidity and mortality. As a member of the Orthomyxoviridae family, IAV inherently possesses a segmented genome, which enables a process of segment transmission between viruses following cellular co-infection, a process termed reassortment. The high rate of IAV mutation and continued co-circulation of diverse viral strains in divergent host species leads to the persistent prospect for emergence of new IAV with pandemic potential. Therefore, it is of great importance …

Understanding The Paradox Of Genetic Diversity In Uropathogenic E. Coli: The Uncommon Evolution Of A Common Pathogen, Henry Louis Schreiber

Arts & Sciences Electronic Theses and Dissertations

Urinary tract infections (UTIs) are the second most common bacterial infection of people in the U.S.A and are frequently recurrent, as an initial UTI is quickly followed by a second episode in 30-35% of cases despite appropriate antibiotic treatment and clearance of the bacteria from the urine. The vast majority, >80%, of UTIs are caused by uropathogenic Escherichia coli (UPEC). UPEC that colonize the bladder are thought to originate in the gut, where they live as commensal organisms. UPEC can be shed in feces to colonize the vagina and/or periurethral area, and then can ascend into the bladder to start …

Lost In Translation, Daniel Pena

Master's Projects and Capstones

At the conclusion of a patient’s hospitalization the Registered Nurse (RN) will review all discharge instructions in the patients room in their preferred language. Plan time for the discharge and facilitate a calm quiet environment, such as the patient’s room with the door closed, if possible. Get the discharge instructions printed out in their preferred language and a set for yourself in English would be best so you are able to review the instructions line by line with them. When the patients medical team, such as but not limited to, medical doctors, pharmacists, physical therapists, and social work have completed …

Investigating The Regulatory Circuitry Of Protein Kinases And Proteases In Apoptosis, Stephanie A. Zukowski

Electronic Thesis and Dissertation Repository

Apoptosis is a tightly regulated cellular process essential for normal development and tissue homeostasis. Perturbations to apoptotic signaling underscores numerous pathogenic processes emphasizing the importance of apoptotic regulation. During apoptosis, caspases orchestrate cellular degradation through proteolytic cleavage of key structural and enzymatic proteins. In a different manner, protein kinases regulate apoptosis by catalyzing the post-translational phosphorylation of substrate proteins to facilitate either pro- or anti-apoptotic signal transduction pathways. Emerging paradigms have indicated that bidirectional crosstalk between protein kinases and caspases serves to globally fine-tune the equilibrium between signals directing cell survival and cell death. In this regard, identifying points of …

Regulation Of Liver Mitochondrial Metabolism During Hibernation By Post-Translational Modification, Katherine E. Mathers

Electronic Thesis and Dissertation Repository

Hibernation, characterized by a seasonal reduction in metabolism and body temperature, allows animals to conserve energy when environmental conditions (e.g. temperature, food availability) are unfavourable. During hibernation, small mammals such as the 13-lined ground squirrel (Ictidomys tridecemlineatus) cycle between two distinct metabolic states: torpor, where metabolic rate is suppressed by >95% and body temperature falls to ~5 °C, and interbout euthermia (IBE), where metabolic rate and body temperature rapidly increase and are maintained at euthermic levels several hours. Suppression of metabolism during entrance into torpor is paralleled by rapid suppression of liver mitochondrial metabolism. In my thesis, I …

Omega-3 Polyunsaturated Fatty Acids: Impact On Oxidative Stress, Antioxidant Responses And Vascular Function, Kayla R. Zehr

Biomedical Sciences ETDs

Cardiovascular disease (CVD) is the leading global cause of death, and cigarette smoking (CS) is a major risk factor for CVD. Although there are smoking cessation programs that include a combination of pharmacological and behavior treatments, failure to curb behavioral habits and pharmacological addiction leads to low cessation success rates. Thus, developing a treatment to decrease CVD risk is critical. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) decrease oxidative stress and have been shown to restore endothelial function, an indicator of CV health, in cigarette smokers. Metabolites of n-3 PUFAs have been shown to have CV-protective effects, but the mechanism by …

Optimizing Transposon Mutagenesis In Vibrio Strains To Identify Genes Involved In Antibiotic Production, Mahnur Khan

Honors Projects

Based on previous studies that have shown the competitive nature of non-pathogenic environmental strains of Vibrio, we hypothesize that environmentally derived bacteria can inhibit Vibrio pathogens, and possibly be a source of novel antibiotics. A previous experiment performed in the lab tested environmental Vibrio strains from various habitats against the pathogenic strains, Vibrio cholerae and Vibrio parahaemolyticus. Of the 3,456 strains collected, members of the Wildschutte lab identified 102 environmental strains of Vibrio that inhibited the growth of both pathogens. The data suggests that environmental Vibrio strains directly inhibit the growth of related pathogens. Our project involves the …

Correction Of Dna Sequencing Data With Spaced Seeds, Stephen Lu

Electronic Thesis and Dissertation Repository

The advent of next-generation sequencing technologies has allowed for the bridging of wet lab work and large data analysis into a cohesive work flow; with the increasing speed and efficiency of sequencing organisms, it becomes imperative that we are able to ensure the data that is produced is correct.

We designed and implemented a new algorithm, QUESS, which based on using multiple spaced seeds to correct DNA sequencing data from Illumina MiSeq, HiSeq and NextSeq machines using C++ and OpenMP for parallel computing. We compared our method with ten leading programs, producing consistently better overall results for most tested measures. …

Mutational Analysis Of The Molluscum Contagiosum Virus Mc160 Protein, Henri Estanbouli

Seton Hall University Dissertations and Theses (ETDs)

The Molluscum Contagiosum Virus (MCV), belongs to a family of large DNA viruses called Poxviridae. MCV causes a common skin infection resulting in benign neoplasms. 122 million cases of MC were reported in 2010. The virus is not primarily lethal, though fatalities have occurred due to secondary bacterial infections. Even with the high volume of reported cases, MCV is very much understudied, and its pathogenicity is not well understood. Thus, with that in mind, a more in-depth understanding of the MCV-host interactions is a priority. Presumably during infection, MCV utilizes immune evasion molecules to inhibit activation of the host pro-inflammatory …

Cholesterol Regulation Of Pulmonary Endothelial Calcium Entry Following Chronic Hypoxia, Bojun Zhang

Biomedical Sciences ETDs

Chronic hypoxia (CH)-induced pulmonary hypertension (PH) is associated with diminished ATP-induced endothelial Ca2+ entry as well as membrane cholesterol in pulmonary arteries. Store-operated Ca2+ entry (SOCE) and depolarization-induced Ca2+ entry are major components of the response to ATP and are similarly decreased after CH. Because endothelium-dependent vasodilation is closely associated with pulmonary endothelial [Ca2+]i, the blunted agonist-induced Ca2+ influx in pulmonary artery endothelial cells (PAEC) may contribute to the development of CH-induced PH. Interestingly, impaired agonist-induced Ca2+ influx in PAEC following CH can be restored by membrane cholesterol supplementation. In the current studies, we hypothesized that impaired Ca2+ entry in …

Comparison Of Bacterial And Archaeal Communities In The Subsurface Versus Surface: Implications For Nitrogen Cycling, Jason C. Kimble 5059801155

Biology ETDs

Arid-land caves are thought to be extremely nitrogen-limited, but almost nothing is known about how microbes in subsurface arid-land environments obtain this essential element to meet cellular demand. The depth of caves beneath the surface may represent a critical factor affecting microbial nitrogen cycling in these environments. Percolation of water and nutrients from a precipitation pulse event would affect deep arid-land carbonate caves at a much slower rate. To obtain nitrogen in deep, carbonate caves, microorganisms could use fixed N in the host rock for assimilatory biochemical pathways or for a respiratory electron acceptor. However, the latter process leads to …

Role Of Asparagine As A Nitrogen Signal And Characterization Of A Nitrogen Responsive Glutamine Amidotransferase, Gat1_2.1 In Arabidopsis Thaliana, Shrikaar Kambhampati

Electronic Thesis and Dissertation Repository

Maintaining the proper balance between carbon (C) and nitrogen (N) metabolism is critical to the sustained growth of organisms. In plant leaves, this balance is achieved by photoperiod dependent cross-talk between the processes of photosynthesis, respiration, and amino acid metabolism. A crucial mechanism in maintaining C/N balance is the GS/GOGAT cycle, which is well known to serve as a cross-road between C and N metabolism. Importantly, non-photosynthetic tissues (e.g. roots, germinating seeds) lack a sufficient supply of carbon skeletons under high N conditions and hence may resort to other mechanisms, along with the GS/GOGAT cycle, to achieve proper C/N balance. …

The Role Of Orphan Nuclear Receptor Dax-1 (Nr0b1) In Human Breast Cancer Cells: Expression, Proliferation And Metastasis, Erin Dishington

Master's Theses

The orphan nuclear hormone receptor DAX-1 (Dosage Sensitive Sex Reversal, Adrenal Hypoplasia Congenita on the X Chromosome, gene 1) plays an important role in the development of adrenal and gonadal tissues and functions as a global negative-regulator of steroidogenesis. In addition, it is known to be involved in several diseases including some cancers. Herein, we describe our examination of the role of DAX-1 in breast cancer, specifically its influence on proliferation and metastasis and its expression during progressive stages of disease. In an effort to understand how DAX-1 influences breast cancer cell proliferation and metastasis, we used MCF7 breast cancer …

Estimating Density And Residency Of Bottlenose Dolphins (Tursiops Truncatus) In Three Estuarine Sites In South Carolina, Jessica Nicole Conway

Electronic Theses and Dissertations

Of the three estuarine bottlenose dolphin stocks in South Carolina, two are considered data insufficient, with no minimum population estimate or assigned potential biological removal value. Additionally, the Northern Georgia Southern South Carolina Estuarine System (NGSSCES) stock’s boundaries are based on sighting data that do not extend to the full area encompassed by the boundary lines. In areas where stock boundaries are not clearly defined and data is insufficient for traditional methods of estimating abundance, density may provide insight into local distributions and serve as a proxy for actual abundance. Photo-identification surveys were conducted in three sites, representative of the …

Nutritional Regulation Of Sulfonamide Antibiotic Biodegradation By Microbacterium Sp. Strain C448, Tonya Malcolm

Electronic Thesis and Dissertation Repository

Sulfonamide antibiotics are frequently released into the environment due to their widespread use in livestock production, imposing a potential selection pressure for the development and dissemination of sulfonamide resistance. Recently, a sulfonamide-degrading bacterium Microbacterium sp. Strain C448 was discovered, whose activity has the potential to be used as a sulfonamide removal strategy from agricultural soils. This research gains insight into the sulfonamide biodegradation pathway by 1) evaluating the nutritional regulation of sulfamethazine biodegradation and 2) undertaking a comparative proteomic analysis of cells grown in the presence and in the absence of sulfamethazine. The nutritional analyses revealed that increasing amounts of …

Identification And Characterization Of Farr And Fare As A Regulator And Effector Of Fatty Acid Resistance In Staphylococcus Aureus, Heba Alnaseri

Electronic Thesis and Dissertation Repository

Although Staphylococcus aureus is exposed to antimicrobial fatty acids on the skin, in nasal secretions and in abscesses, specific mechanisms for regulating gene expression and intrinsic resistance in response to these fatty acids have not been reported. Through in vitro selection for increased resistance of S. aureus to linoleic acid, I identified fatty acid resistant clone FAR7, where a single nucleotide polymorphism caused a His₁₂₁Tyr substitution in an uncharacterized member of the TetR family of transcriptional regulators, which is divergently transcribed from a gene encoding a member of the resistance-nodulation-division superfamily of multi-drug efflux pumps. I named these …

Characterizing The Interaction Between Human Adenovirus E1a And Sting, Jessica Hill

Electronic Thesis and Dissertation Repository

When challenged by viral DNA, the cytoplasmic DNA sensor cyclic GMP-AMP synthase (cGAS) signals through the adaptor protein stimulator of interferon genes (STING) to induce a primary type I IFN response. Studies from recent years have also revealed shared architecture between metabolism and innate immunity. Viruses have evolved to counteract these mechanisms. Human adenovirus (HAdV) early region 1A (E1A) protein antagonizes the cGAS-STING pathway to prevent an innate immune response by physically interacting with STING. I hypothesize that the interaction between E1A and STING is mediated through several motifs and involves ribosomal protein S6 kinase beta-1 (S6K1). Using a series …

Aging, Inflammation, And Gut Microbiota In Mice, Jody Demeo

Honors Projects

Inflammation and gut microbiota are two areas of study that can be linked to aging in the body. As a person ages, systemic inflammation tends to increase, and changes in microbiota in the gastrointestinal system occur as well.

Saving The Planet Begins With Saving The Coral Reefs, Marla Maconochie

Honors Projects

This honors project uses a children’s book format to aid in explaining the importance of saving the coral reefs. This book will be informing the younger generations about important, yet complicated issues at hand in a way that they can understand and relate to. The book explains how coral reefs are important for oxygen production, biodiversity, research opportunities, protection of coastal environments and for the economy. The children’s book explains how human activities and natural stressors can impact coral survivorship. The book explains how overfishing allows for excessive algal growth that smothers corals and tackles how coral bleaching occurs and …

Habitat Use Of Blacktip Sharks (Carcharhinus Limbatus) At Fishing Piers, Kelsey L. Spencer

Electronic Theses and Dissertations

Blacktip sharks (Carcharhinus limbatus) can be observed near fishing piers throughout the summer along the northeast coast of South Carolina. These piers attract and support a wide variety of potential prey and sharks are able to forage on fishers’ discards with minimal energetic cost. I tagged 12 blacktip sharks with acoustic transmitters, monitored piers with acoustic receivers, and conducted pier-creel surveys to determine the habitat use of blacktip sharks at fishing piers, factors that influenced residence time and presence/absence at piers, and any cyclical patterns in visits to piers. Data were analyzed with pier association indices (PAI), mixed models, and …

Identification And Quantification Of Cyanide And Its Metabolites In Lemur Urine, Jeremy Peralta

Student Theses

Cyanide is a chemical compound that contains the monovalent groups of carbon and nitrogen. This substance is considered a rapidly acting deadly chemical. However, some animals such as lemurs consume food products that are known to contain elevated levels of cyanide without major consequences. The mechanism by which the lemur can handle this high exposure to cyanide is unknown. In this study, we developed and validated two analytical methods for the determination of cyanide and two metabolites, thiocyanate and 2-aminothiazoline-4-carboxylic acid (ATCA) in lemur urine. The method was applied to 47 authentic lemur urine samples collected from 4 different species …

Analysis Of Heart Muscle Tissue For Detection Of Fluorescently Labeled Cells In Conventional- And Frozen-Section Tissue Preparations, Lena Anna Mitchell

Honors Theses

No abstract provided.

Forage Selection And Habitat Architecture As Drivers Of Small Mammal Community Dynamics In An Arid, Nutrient Limited, Highly Stochastic Ecosystem, Jennifer Darby Noble

Biology ETDs

In the Northern Chihuahuan desert, grassland and shrubland co-occur as separate stable states under similar climatic conditions. In this bottom up (resource driven) system, the magnitude and timing of precipitation events drives primary production which varies from year to year and season to season. Climate change is predicted to alter precipitation regimes, and increase aridity, facilitating shrub encroachment which results in increased landscape heterogeneity and a decrease in plant biodiversity. These changes will likely result in a restructuring of small mammal communities.

We used long-term data on precipitation, primary production, and abundances of small mammals in adjacent grassland and shrubland …