Hunter Brady

Assessment of Antiviral Activity of Chlorine Dioxide Gas

Faculty Mentor: Anthony Newsome
Hometown: Murfreesboro, TN

Abstract: Since the emergence of the SARS-CoV-2 virus, the need to identify antiviral agents to disinfect large areas has greatly increased. Chlorine dioxide (ClO2) gas has previously been identified as an antibacterial agent with strong oxidizing capabilities. The MS2 bacteriophage has previously been identified as a suitable surrogate for the development and application of virucide decontamination methods. The purpose of this study was to identify and assess the antiviral properties of ClO2 gas and to determine optimum physical conditions for potential deployment in support of current antiviral disinfection needs. Using the MS2 bacteriophage model system, preliminary studies used the double-layer agar plaque assay technique to evaluate the antiviral activity of ClO2 gas. Initial results support the use of ClO2 gas as an antiviral agent. Reduction of up to six logs was observed with treatments of 200 ppm of ClO2 gas following overnight treatment on a non-porous surface such as steel coupons. Lesser exposure times studies were also effective in multiple log reductions of the MS2 bacteriophage. Studies are now being directed at the ability to inactivate MS2 phage imbedded in porous surfaces such as cloth. It has been determined that infective MS2 bacteriophage can be recovered after being imbedded on a cloth substrate. This can serve as a basis to evaluate MS2 phage inactivation when imbedded in porous substrates such as cloth.

Logan Carver

The Interaction of N-MYC and WDR5: Therapeutic Potential in Neuroblastoma

Faculty Mentor: April Weissmiller
Hometown: Nashville, TN

Abstract: Neuroblastoma (NB) is a cancer originating in the nerve cells and the most common extracranial tumor affecting children. The survival rate for high-risk NB is less than 50%. High-risk NB is associated with increased activity of N-MYC, a transcription factor that regulates thousands of genes involved in cell growth and metabolism. Unfortunately, blocking N-MYC directly has failed to be a viable option for therapeutics, necessitating a deeper investigation into new ways to inhibit N-MYC. One novel approach to target NMYC is to target an important co-factor that N-MYC needs to function as a transcription factor. Evidence in other types of cancers has revealed that WDR5 is a critical cofactor that recruits N-MYC to genes known to be essential for biomass accumulation. The present study sought to investigate the influence of the N-MYC-WDR5 interaction on the ability of N-MYC to bind chromatin and promote transcription in neuroblastoma cells using NB cell lines engineered to induce wild-type N-MYC (WT), a version of N-MYC that cannot bind WDR5 (WBM), or a green fluorescent protein (GFP) as a control. Results reveal that N-MYC expression in the induced cell lines is comparable to other N-MYC amplified cell lines and that inhibition of the N-MYC-WDR5 interaction using the WBM cell line reduces the level of N-MYC that binds chromatin. Consistent with a decrease in N-MYC binding, transcript levels of these same N-MYC-WDR5 targets are decreased in the WBM cell line as well. These results provide a solid foundation for the use of this model system to further probe the consequence of the N-MYC-WDR5 interaction on multiple facets of N-MYC function.

Maria Clark

Synthesis and Characterization of the Therapeutic Potential of Antifungal Peptoid β-5

Faculty Mentor: Kevin Bicker
Hometown: Murfreesboro, TN

Abstract: C. neoformans is a pathogenic yeast species that is one of the leading causes of Cryptococcal meningitis. This form of meningitis, which begins with the inhalation of yeast spores, has a significant mortality rate of 81% percent, with high incidence in those who are immunocompromised. Current antifungal treatments such as fluconazole and amphotericin B have detrimental side effects, leaving a significant need for better alternative treatments. Peptoids, which are mimics of the natural peptides found in living organisms, exhibit beneficial characteristics such as protease degradation evasion and therefore longer half-lives, offer an alternative route for antifungal compound development. Peptoid compounds discovered in our own lab, such as β-5, must be characterized by determining efficacy against pathogenic species such as C. neoformans as well as the toxicity of the compounds in the presence of mammalian cells. Herein, assays for determining these factors have shown that β-5 has low toxicity in several mammalian cell lines and significant and rapid inhibition of C. neoformans. These characteristics, which are linked to the compound's structure, suggest that future investigation can focus on working to further enhance the compound's overall efficacy through structural modification.

DaVonte Lewis

From superconductor to Anderson Insulator: harnessing disorder in quantum materials

Faculty Mentor: Hanna Terletska
Hometown: Camp Springs, MD

Abstract: Superconductors are 21st-century quantum materials that promise fascinating technological and societal benefits once properly harnessed. One of the hurdles we face towards that end is that of disorder: the inherent impurities and imperfections that exist in all real materials. Recently, there has been significant progress in the development of numerical tools capable of treating different ranges of disorder, allowing for a more robust investigation into its effects on the spectral and conducting properties of materials. In this work, using the in-house typical-medium theory of the single-site attractive Hubbard model on a Bethe lattice, we aim to explore the effects of strong disorder on superconductive properties. In particular, our focus is the study of disorder induced Anderson localization and the associated superconductor-insulator transition (SIT). We construct a phase diagram in the disorder and electronelectron interaction parameter space and demonstrate how sufficiently strong disorder can destroy superconductivity in materials. Studying this disorder-induced transformation of material properties is not only of intellectual interest, but also paves the way for the use of disorder as a means to tune material conductance—ultimately reframing disorder as an exploitable design parameter rather than a limiting factor in the development of novel quantum materials.

Sophia Taylor

Synthetic Organic Electrochemistry in Deep Eutectic Solvents

Faculty Mentor: Scott Handy
Hometown: Nashville, TN

Abstract: Electrochemistry is an increasingly well-known method of organic synthesis due to its sustainability. Organic electrochemical synthesis requires an electrolyte, or a salt, to facilitate charge transport in addition to a solvent. Both the electrolyte and the solvent are sources of waste in an organic reaction and thus contribute to its environmental impact. Deep Eutectic Solvents (DES) are increasingly well-known recyclable liquids that contain salts as at least one of their components. The use of DES as organic electrochemical solvents is explored for the first time. By performing various allylations of aldehydes using different DES and electrode pairings and analyzing percent yields of each round, reaction conditions are optimized. The recyclability of the DES is also explored. It is discovered that DES are excellent solvents to use for electrochemical allylations because each 2 mL of DES can be reused at least three times. The combination of electrochemistry and DES yields a doubly green synthetic reaction which can be replicated in many large-scale settings, such as the pharmaceuticals industry. Doing so would minimize waste production and allow for reusable materials, saving both money and the environment.

Carina Vazquez

Experimental Composition of Two Systems: Ring Resonator Structures and an Acoustic Demultiplexer

Faculty Mentor: William Robertson
Hometown: Shelbyville,TN

Abstract: In this work, we experimentally investigated two acoustic systems: the Y-shaped demultiplexer and the acoustic ring resonator. A demultiplexer separates and transmits specific frequencies from a broadband input signal. The acoustic demultiplexer investigated here is based on resonances created by sideattached waveguide stubs. The Y shaped waveguide sent broad bandwidth sound along an input line. Two output lines with a stub filter arrangement transmitted narrow bands of two different frequencies separated from the broadband input. Ring resonators are widely used in optics as filters and switches. Here we investigated the acoustic analog to the optical ring resonator. The acoustic ring resonators consist of a circular waveguide attached tangential to a straight waveguide. The ring waveguide has resonances whenever the path around the ring equals an odd half-integer multiple of the wavelength. We showed that this phenomenon can be used to create notch filters, add-drop filters, and broad acoustic bandgap reflectors. The experimental results were in good agreement with numerical models rendered in python and finite-element simulations using COMSOL.

Sydney Wilson

Analyzing the Spectral Characteristics of Propagations Teepees

Faculty Mentor: Chuck Higgins
Hometown: Smyrna, TN

Abstract: A high frequency spectral feature has been previously identified in ground-based spectrographs and recorded by a group of citizen scientists from the Radio JOVE project (Fung et al., 2020 GRL, 47, e2020GL087307; https://doi.org/10.1029/2020GL087307). This feature is a teepee (TP) tent shape found in data between 15 to 30 MHz, where the spectral enhancement frequency increases and then decreases with time, hence the name (Figure 1). The presence of these features is currently being attributed to ionospheric reflection of VHF emissions from lightning activities in remote thunderstorms. In this study, we will analyze TP observations by studying their times (seasons) of occurrences, duration, apex frequency, upper cutoff frequency drift rates, and quality, to better understand these spectral features. Analysis was completed using the Autoplot software (http://autoplot.org), and these characteristics and statistics are presented in order to gain a deeper understanding of these peculiar spectral features.

Aric Moilanen

Taming Disorder in Quantum Materials

Faculty Mentor: Hanna Terletska

Abstract:The discovery of new materials is a cornerstone of human civilization and development. We live in the era of quantum materials which offer tremendous opportunities for fundamental research and advances in new-generation technologies. Progress in this field will enable energy efficient storage and transmission, faster and powerful electronic devices, novel sensors, and quantum computers. Such research can bolster economies, advance the quality of life, and address the unprecedented growth in global energy needs. One essential part of such research is the accurate simulation and theoretical modeling of these materials. However, the very same properties that make these materials so useful also make them exceedingly difficult to simulate and understand. One major obstacle is understanding the effects of disorder, or imperfections, in a material. Disorder is ubiquitous in materials and can profoundly affect their properties and functionality. The focus of our research is how disorder turns a conductor to an insulator in a phenomenon known as the metal-insulator transition (MIT). Here, we propose a new, greatly simplified model for identifying MITs in a disordered system that both agrees with past simulations and significantly reduces computational complexity, bringing us one step closer to better modeling and control of properties of quantum materials.

Lillian Beck

Correlation Between Mean Length of Utterances in Preschoolers and Different Maternal Education Backgrounds

Faculty Mentor: Kathryn Blankenship

Abstract: Purpose: The purpose of this study was to measure the mean length of utterances in typically developing preschool children and to identify whether maternal education is an influential variable in morphological development. The study also researched the relationship between mean length of utterance (MLU) and number of different words (NDW).

Methods: 13 preschoolers between the ages of 3 and 5 were recruited to participate in the study. To participate in the study, each participant had to be typically-developing in the area of language, nonverbal cognitive abilities and hearing. This was assessed using standardized measures. Then, a 15-minute language sample was taken and was analyzed for MLU and NDW.

Results: The results of this study showed that there was a medium correlation between MLU and maternal education and between MLU and NDW; however, statistical significance was not reached. The results suggest that as maternal education increased (e.g., mother's with higher levels of education) so did the length of MLU in the participants such that the participants from higher maternal education families had longer MLUs. Additionally, the results suggest that there is a relationship between NDW and MLU such that as the participants who had larger NDW had longer MLU.

Jared Frazier

Practical Investigation of Direct Analysis in Real Time Mass Spectrometry for Fast Screening of Explosives

Faculty Mentor: Mengliang Zhang

Abstract: While the direct analysis in real time (DART) ionization source coupled with mass spectrometry (MS) is viable for the screening of trace explosives, current and previous methods have significant disadvantages for screening of explosives. This work demonstrates novel methods using DART-MS for the high-throughput and sensitive detection of nineteen organic explosive residues in four different categories deposited on several substrates. Explosive residues were selected based on their use in historical bombings that have tragically claimed the lives of civilians and the armed forces of many nations. To combat the threat of explosives to national security, several methods were investigated using DART-MS. The QuickstripTM sample card method was used to optimize DART gas heater temperature as well as dopants. Four sample introducing strategies for DART-MS including transmission, thermal desorption, closed mesh, and direct-insert methods were implemented to analyze liquid and dried samples deposited on five substrates. Fabric, leather, metal, plastic, and synthetic skin were selected to simulate realistic matrices for explosive residues. It was found that representative explosives from each category could be detected with nanogram sensitivity and in less than 1 O seconds. Therefore, the proposed methods using DART-MS provide prompt analysis of explosives for forensic applications.

Kayley Stallings

Effect of Tea Brewing Temperature and Tea Concentration on the Microbial Profile of Kombucha

Faculty Mentor: Keely O'Brien

Abstract: Kombucha, a fermented tea made with a symbiotic colony of bacteria and yeast (SCOBY), has been touted as a health beverage for years. Previously, the health benefits attributed to kombucha have been primarily anecdotal; however, as kombucha consumption has increased, scientists are beginning to question what causes the supposed benefits, with many researchers attributing the advantages to kombucha's microbial ecosystem. Previous research examining kombucha produced with different types of tea demonstrated many variations in the microbiome. Therefore, manipulating the amount of tea used and the tea brewing methods may affect the microbiome of kombucha as well. This study was conducted to determine how different kombucha production techniques - tea concentration and steeping temperature - alter the kombucha's microbiome. For this project, kombucha was made using varying concentrations of black tea and a range of brewing temperatures to determine if either had an effect on the microbial profile. The teas were fermented to the desired end-point and were then plated on selective agars to identify and quantify the types of microbes present. The results of this study will provide further insight into how different production practices affect the microbial profile of kombucha and how that might translate to the wellbeing of the consumer.

Lily Medley

Geochemical and Petrographic Attributes of Lavas Erupted at Small Volcanic Centers in Northern Oregon: Implications for Magma Formation Within an Intra-Volcanic Arc Graben

Faculty Mentor: Warner Cribb

Abstract: Quaternary volcanism in the northern Oregon Cascade Range is dominated by eruption of calc-alkaline andesite to rhyodacite lava flows and associated pyroclastic deposits at long-lived, subduction-driven composite volcanoes, such as Mt. Hood and Mount Jefferson. This study investigates small and more mafic Quaternary volcanoes in the Mt. Hood vicinity, including Clear Lake Butte (CLB), Pinhead Buttes (PHB), and Olallie Butte (OB). These volcanoes are located within an intra-volcanic arc graben, which developed approximately 7-8 Ma to the south and propagated northward to the Mt. Hood region. The research objective is to identify geochemical and petrographic similarities and differences among intra-arc graben lavas in order to better understand the conditions of magma formation at small volcanoes in the central to northern Oregon Cascade Range. This research is a comparison of geochemical and petrographic characteristics of Quaternary basalt and basaltic andesite lavas erupted at small volcanoes within the northern graben to those of primary and near-primary lavas, mainly erupted within southern graben regions.

Tia Shutes

Initiation and Cannabinoid Assessment of Trichomes on Industrial Hemp (Cannabis sativa) Tissue Callus

Faculty Mentor: John DuBois

Abstract: Industrial hemp, Cannabis sativa L., is a species of the Cannabaceae family, used for many medical and industrial purposes, which centers around the cannabinoids of tetrahydrocannabinol (THC) and cannabidiol (CBD). These compounds are produced in trichomes (microscopic plant hairs), located on the surface of the plant. The objective of this project was to initiate trichomes via callus of various industrial hemp varieties and assess the cannabinoid concentration within the trichomes. using high performance liquid chromatography (HPLC). HPLC analysis of the callus produced from the Cherry, Cherry Blossom, and Cherry x Workhorse varieties showed promising presence of CBD. By successfully achieving this objective, researchers will have the ability to more effectively study trichome growth and cannabinoid production under laboratory conditions, which could ultimately lead to breakthroughs in future botany research and holistic medical discoveries.

Dirhat Mohammed

Graduate Teaching Assistants' Cognition Related to Teaching: A Comparison of STEM and Non-STEM Groups

Faculty Mentor: Grant E. Gardner

Abstract: Graduate teaching assistants (GTAs) teach a large number of undergraduate students in many university departments, yet receive few opportunities for teaching professional development (PD). Understanding how to design effective, evidence-based PD requires scholars to first recognize graduate students' perception of teaching and learning that they bring to the classroom. However, there is very little research dedicated to measuring these variables related to effective teaching in GT As. Given the wide spectrum of disciplines that GTAs teach in, to better enhance the undergraduate education quality, the quality of PD programs for the GTA must be improved. This study examines whether STEM and non-STEM GT As cognition related to teaching differ between cognitive subscales of the instruments used, as well as whether there is a change in cognitive subscales on these instruments between pre- and post-surveys. Five instruments were used with a sample of n = 52 GTAs from various departments at a large southeastern university: Teacher Beliefs Instrument, Pedagogical Discontentment Inventory, Teaching Self-Efficacy Beliefs, Goal Orientations Toward Teaching, and the Instructional Practices. Results showed that there is no statistical difference between STEM and non-STEM groups' cognition related to teaching, and there were changes in the cognitive subscales over pre- and post-surveys.