National Conference on Undergraduate Research (NCUR) Presenters
The 2022 National Conference on Undergraduate Research was held virtually due to the COVID-19 pandemic. We would like to feature our undergraduate researchers who were selected to present at the National Conference on Undergraduate Research. Here are their projects and abstracts.
MTSU's 2022 Selected NCUR Participants
Ashton Bazzel
Environmental Temperature Effects on Milk Production and Daily Activity of Dairy Cows, with Respect to Different Breeds
Faculty mentor: Jessica Carter (Agriculture)
Heat stress is an animal’s response to an increase in thermal environment that causes the animal to inadequately dissipate heat out of the body. This stress occurs at temperatures over 77°F, when cows are unable to cool themselves down. This increase in heat stress causes a decrease in milk production because more energy is needed to cool down, so there is less energy focused on producing milk. Temperature and relative humidity data, as well as daily milk yield, daily activity, and conductivity, were measured for three 6-week periods during different seasons to determine the effects of environmental temperature on milk production and activity levels. Cows produced more milk during the spring period (p < 0.0001), cows had a higher conductivity in the summer (p < 0.0001), Jerseys were more active through each period than Holsteins were (p < 0.0001), and mild heat stress occurred in the summer with an average THI index of 76.3. The optimum temperature range for Jerseys occurred during the spring period (18°C average temperature), while the optimum temperature for Holsteins occurred during the winter period (8.5°C average temperature).
Alison Blanton
Effects of Heat Stress on Blood Metabolites and Milk Quality in Lactating Holstein and Jersey Cows
Faculty Mentors: Jessica Carter (Agriculture)
Regulating heat stress caused by relatively high ambient temperatures and humidity hasbecome a challenge for dairy producers in the Southeastern United States, especially in the faceof rising global temperatures. Dairy cows are most susceptible to heat stress during periods ofhigh temperatures combined with high humidity due to the cows’ diminished ability to utilizeevaporative cooling in these environmental conditions (West, 2003). Heat stress poses a varietyof problems for dairy cows including decreased immune function (Dahl, 2020), decreased drymatter intake, decreased milk yield (Zhao, 2019), and increased somatic cell count (Hammami,2013). The effects of heat stress on milk quality factors and blood metabolites were observed inHolstein and Jersey cows under varying severities of heat stress (n = 12/ 6 = Holstein, 6 =Jersey). Milk quality was assessed using increasing somatic cell count (SCC), conductivity, andbacterial load as indicators of milk quality. Concentrations of some blood metabolites such ascalcium (Ca), potassium (K), sodium (Na), blood urea nitrogen (BUN), albumin (Alb), glucose,cholesterol, and non-esterified fatty acids (NEFA) were monitored for changes in order to find apotential connected between expected milk quality decline and changes in blood metaboliteconcentrations. Many significant differences relating to increases in SCC (p = 0.0936) andconductivity (p = 0.0195) were observed indicating the expected decrease in milk quality.However, there were no significant findings relating bacterial load to heat stress or breed.Furthermore, some significant differences concerning blood metabolites, such as Mg (p =0.0388), will require more research to ascertain a better understanding of the underlyingmechanisms. Overall, while the connection between blood metabolite concentrations and milkquality still remains unclear, this research supports that heat stress should be avoided as much aspossible in order to produce the highest quality milk.
Hunter Brady
Chlorine Dioxide Gas: Potential for Use as an Anti-viral Agent
Faculty Mentor: Anthony Newsome (Biology)
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.
Ha Bui
The Application of IRT in Analyzing K-8 Teachers’ Responses about Computer Science Implementation
Faculty Mentor: Elizabeth Dyer (TSEC)
As computational thinking becomes a fundamental skill in the digital world of the 21st century, many states in the US, including Tennessee, have introduced standards for teaching computer science (CS) in K-8 schools. Although the state standards have been important guidelines to initiate the integration of CS into classrooms, the barriers that prevent effective teaching and learning remain unclear. Barriers that K-8 teachers are facing can be both internal (lack of CS knowledge and skills) or external (lack of time and curriculum support). In Spring 2020, we developed and administered a needs survey to determine the readiness of TN K-8 teachers and the challenges that they are facing. We aimed to answer two questions: “How do teachers’ reported needs and implementation barriers for the new CS standards differ for elementary and middle school teachers?” and “Does this differ by familiarity with the standards?” We applied Rasch modeling to create four different scales (CURRICULUM-based PD, CS TOPICS to Learn, BARRIERS to Implementation CS standards, and STUDENT-focused Orientation), all of which show strong measurement properties. The scores were then compared using a t-test for independent groups. We found differences in needs and barriers by grade level, but not familiarity. For example, middle school teachers reported higher usefulness of curriculum-based professional development (M = 0.18, SD = 0.80) than elementary teachers (M = -0.064, SD = 0.74), t (127) =-2.00, p = 0.047. Although we did not find enough evidence of differences by familiarity, it is possible that differences by familiarity will be more obvious when teachers have larger variations in familiarity. These findings provide insights to understand the specific barriers and needs of different teacher groups. From this, the most effective support may be tailored to help elementary and middle school teachers differently.
Logan Carver
The Interaction of N-MYC and WDR5: Therapeutic Potential in Neuroblastoma
Faculty Mentor: April Weissmiller (Biology)
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 N-MYC 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 (Chemistry)
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.
Sarah Garris
Comparison of Media Components for Somatic Embryogenesis in Tissue Callus of Vitis aestivalis ‘Norton/Cynthiana
Faculty Mentor: John Dubois (Biology)
Vitis aestivalis, also known as Norton/Cynthiana, is a hybrid North American-European grapevine that produces pleasant wine and exhibits favorable cold and disease resistance as compared to environmental susceptibility of popular European vines. Despite these beneficial traits, this cultivar fails 80% – 90% of traditional dormant cutting propagation attempts, so vineyards are difficult to develop. Traditional propagation techniques such as heated rooting beds and mist tables only marginally improve propagation rates. Tissue culture has successfully improved other cultivars’ propagation and has the potential to improve Norton/Cynthiana propagation. Tissue culturing forces sample tissue into an undifferentiated cellular state called callus. Once callus is produced, a hormone protocol can induce embryo development, termed embryogenesis. Previous studies attempted to establish an embryogenesis protocol without success. In testing common media components, they compared nutritional salts Lloyd & McCown (LM) to Murashige & Skoog (MS), resulting in contradictory data. In this study, callus was suspended in a series of liquid media to compare nutritional salts and varying proportions of 2,4-dichlorophenoxyacetic acid (2,4-D) and benzylaminopurine (BAP) with the goal of establishing a superior media composition to promote healthy callus growth and prevent excess cell death or contamination. Media containing MS salts had lower rates of contamination compared to LM media. As well as less contamination, MS media with proportions of BAP greater than 0.25 µL showed improved callus growth and associated accelerated cell death. There were no differences in LM callus growth based on BAP level, nor in media groups comparing differing 2,4-D ratios. In addition to the planned protocol, prolonged discrepancies of kinetin and 2,4-D ratios in semi-solid maintenance media resulted in the growth of roots on several plates.
Shelby Howard
Does Religion Moderate the Influence of Sex on Emotional Intimacy?
Faculty Mentor: Rebecca Oldham (Human Sciences)
This project was interested in whether religion affects the association between how much romantic partners progress in their sexual behaviors and how much emotional intimacy they experience in their relationship, which has been relatively unexplored in previous research. Neurological research has found that sex can increase feelings of bonding through oxytocin and dopamine, which are released during orgasm. However, according to sexual scripting theory and the moral incongruence hypothesis, religious people may have negative emotional reactions because premarital sex violates the expectations and values of their religious community. For example, while porn can improve sexual satisfaction for non-religious people, it often has the opposite effect for those who are highly religious. This study combined two samples (N = 1,268)—one that recruited participants via social media from across the United States (n = 306) and the other which recruited college students from a southwestern university (n = 962). Participants completed an online survey measuring what sexual behaviors they had engaged in with their partner, several indicators of religion (i.e., religiosity, religious attendance, religious affiliation, evangelicalism, and fundamentalism), and the amount of emotional intimacy in their relationship. We found that, of the five measures of religion, only fundamentalism moderated the association between sexual behaviors and emotional intimacy, such that being more fundamentalist slightly diminished the positive emotional effects that sexual behaviors had on their relationship. This is important because few sexuality and religion studies have explored fundamentalism as a variable. That this measure of religion was the only significant moderator suggests that future sexuality research should further investigate the unique influence of fundamentalism on sex and relationships.
Saman Kittani
Reports of Self-Talk when recalling disruptive, anxious, and sad events: Novel experimental design in the study of self-talk
Faculty Mentor: Tom Brinthaupt (Psychology)
Researchers conceptualize intrapersonal communication in many ways. Examples include self-talk, internal dialogues, and inner speech. Said communication has theoretical and empirical connections to many other psychological concepts (e.g., anxiety, cognitive disruption, etc.). However, research attempting to uncover these connections between intrapersonal communication (e.g., self-talk, internal dialogues, etc.) have mainly utilized non-experimental methods. The primarily correlational studies are insightful, but they fail to create causal links between self-talk/internal dialogue and psychological concepts. The present paper aims to drive future intrapersonal communication scientific inquiry to use experimental methodology. In this study, we test the role of self-talk under conditions of cognitive disruption, anxiety, and sadness. We do so by implementing a 2x4 mixed methods design (N = 211). The participants began by reporting their current self-talk and were then randomly assigned to one of four groups: cognitive disruption, anxiety, sadness, or control. Following their assignment, the non-control participants were instructed to recall a memory in which they felt the respective group phenomena. The experimental groups recalled their self-talk during the time the event occurred, while the control group reported their current self-talk again. Finally, the experimental groups reported the memory recalled. The mixed methods ANOVA did not result in self-talk main effects for both time (pre vs. post) and recall condition (anxiety, cognitive disruption, upsetting). However, there was a significant interaction. Specifically, the post-self-talk was significantly higher than the pre-self-talk within the anxiety condition. The results reinforce previous findings on the relationship of anxiety and self-talk. The freedom for participants to recall any memory (one they believe made them feel anxious, disrupted, or upset) may have hurt our power to find significant results with the other levels. However, the memory description allows us to create further experimental studies which attempt to recreate similar events that that lead to cognitive or emotional disruption.
DaVonte Lewis
From Superconductor to Anderson Insulator: Harnessing Disorder in Quantum Materials
Faculty Mentor: Hanna Terletska (Physics and Astronomy)
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 electron-electron 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.
Jack Maxwell
Investigating the Significance of SWI/SNF on MYCdependent Transcription in Malignant Rhabdoid Tumor
Faculty Mentors: April Weissmiller (Biology)
Malignant rhabdoid tumor (MRT) is a rare pediatric cancer that usually affects children under two years of age. Due to the aggressive nature of the cancer as well as the dearth of treatment options, MRT has an extremely high mortality rate. The hallmark mutation of MRT is biallelic loss or inactivation of the gene SMARCB1, which codes for the tumor suppressing SNF5 subunit of the SWI/SNF chromatin remodeling complex. Previous studies have elucidated one mechanism by which this mutation can result in MRT. Loss of SNF5 allows the oncoprotein transcription factor MYC unrestricted access to its target genes, increasing transcription of genes necessary for tumor malignancy. Recently, we uncovered that residual SWI/SNF (rSWI/SNF) subunits colocalize extensively with MYC on chromatin in MRT cell lines, however whether rSWI/SNF impacts the ability of MYC to drive an oncogenic transcriptional program in MRT is unknown. Therefore, we used a combination of biochemical and genome-wide experiments to begin to uncover the influence that rSWI/SNF complexes have on MYC function and the greater chromatin landscape in MRT. Data so far show that degradation of the SWI/SNF ATPase, BRG1, results in decreased gene expression of known MYC target genes. In addition, gene expression changes that occur as a result of acute depletion of BRG1 mimic those following depletion of MYC. Together these data suggest that at least one function of rSWI/SNF complexes is to facilitate MYC-driven transcription in MRT, and that targeting the BRG1 subunit of the rSWI/SNF complex may serve as a way to target MYC in this cancer. These results open up a multitude of key questions that we are actively pursuing, such as examination of the chromatin state at MYC target genes and determining how broadly significant these findings are in other MRT cell lines.
Nash Meade
The Creature from the British Isles: The Historical and Contemporary Importance of Thomas Hobbes’ Political Philosophy
Faculty Mentor: Ron Bombardi (Philosophy and Religious Studies)
Political philosophy is of central importance to much of the goings-on of a nation. Among the political theorists, however, one man often stands on the outside, even though he is commonly addressed in those works which do make it to the forefront: Thomas Hobbes. Hobbes is often cited as too pessimistic or too intent on the necessity of authoritarianism. Although neither point is untrue, his work encompasses much more than these two points, often having far more significance than many would be willing to admit. This presentation gives an account of Hobbes’ historical importance and the reactions which he evoked, specifically in the work of John Locke and Jean-Jacques Rousseau, before progressing into his more contemporary importance amid a pandemic situation. It further delves into his contemporary importance by examining the Trump and Biden administration’s respective responses to the ongoing COVID pandemic. Hobbes believed that one of humanity’s driving factors is fear and, with the current political and social situations being created by the pandemic, his fear-based political philosophy has become strikingly significant and prescient once again, which may point to a resurging importance of security—even of the authoritarian kind—in place of freedom when the world is faced with an uncertain future.
Isaiah Osborne
K2-Reduction and Invertibility of Unicyclic Graphs and Bicyclic Graphs
Faculty Mentor: Dong Ye (Mathematical Sciences)
Let G be a graph with n vertices. An adjacency matrix of G is an(n × n)-matrix A(G) where the entry aij= 0 if the two vertices i and j are nonadjacent, and aij = 1 if the two vertices i and j are adjacent. A graph is considered invertible if its adjacency matrix is invertible, and a graph is sign-invertible if the entry of the inverse of its adjacency matrixis 0,−1 or 1. Invertibility of graphs can be determined by analyzing the determinants of their adjacency matrices. However, it is not easy to determine the invertibility of a family of graphs in a general way. In this project, we use K2-reduction operation to study the invertibility of sparse graphs, especially for unicyclic graphs and bicyclic graphs, where a unicycle graph is a graph with exactly one cycle while a bicyclic graph is a graph with two edges whose removal results in a graph without cycles.
Cassandra Perrone
Cloning Successive Generations of Industrial Hemp (Cannabis sativa) to Assess Cannabinoid Profiles
Faculty Mentors: John Dubois (Biology)
Industrial hemp (Cannabis sativa) has made a remarkable impact worldwide due to the plant’s beneficial properties and versatile use. Within the last decade, there has been a rapid increase in C. sativa research studies in multiple industries. The medical studies on C. sativa revolve around the specific cannabinoid CBD (cannabidiol) and its therapeutic properties; the research has shown that the cannabinoid can decrease the overall symptoms associated with multiple chronic illnesses and diseases.
This research project focuses on the idea that every cloned plant contains the exact same genetic information and, therefore, theoretically should have the same metabolic profile of cannabinoids through all the successive generations grown. Vegetative cuttings (clones) of C. sativa is the preferred propagation technique to be the most effective to retain the same genetic information and to reduce hybridization and mutations. A known issue with repeatedly cloned plants is that, over time, a metabolic function can be lost, and in C. sativa, the function of interest is producing cannabinoids. The objective of this project is to assess cannabinoid profile concentrations of successively cloned generations of 5 varieties: Cherry, Cherry Blossom, Cherry x Workhorse, Sour Space Candy, and The Wife.
Pranathi Shankar
Can priming information about body odor affect perceptions of competence in a virtual interview?
Faculty Mentor: Jessica Gaby (Psychology)
Multiple factors affect our daily interactions with the people around us. The way they look, talk, dress, and even smell help us create a better impression of a person in our minds and research has reinforced that knowing details about a person before meeting can impact our first impression of them. Previous research has also shown that we also associate certain scents to being professional or unprofessional. Ever since the pandemic, job interviews have required virtual interviews rather than in-person ones. Hence, learning whether previous information about a candidate can impact their perceived level of competency is important. The purpose of this study is to investigate whether the mere suggestion of having a certain type of body odor could make a difference in how participants determine the effectiveness of a potential employee during a virtual interview. In the study, participants are asked to rate pre-recorded videos of a candidate answering interview questions. There are three different conditions that the participants are randomly placed into: a control group that receives no previous information about the interviewee, a group that receives the information that the interviewee has nice shoes, or a group that receives the information that the interviewee smells really nice. Participants are then asked to view the pre-recorded interview who answers six basic interview questions. They are then asked to rate the interviewee’s overall performance in each of those 6 questions. They are also asked questions about their own sense of smell, and how sensitive they are to different types of smells. Final results are derived by creating a composite score of answers to the overall performance questions. The results thus far show that there isn't a significant difference in how information priming affects people's perceptions about competence of an individual in a virtual interview setting.
Sophia Taylor
Synthetic Organic Electrochemistry in Deep Eutectic Solvents
Faculty Mentor: Scott Handy (Chemistry)
Electrochemistry is an increasingly well-known method of organic synthesis due to its sustainability and specific reaction manipulation capabilities. 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 the 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, and other reaction components such as SnCl2 are easily regenerated for future use. The combination of electrochemistry and DES yields a doubly green synthetic reaction that 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 (Physics and Astronomy)
The application of acoustic ring resonator structures for the manipulation of audio frequency acoustic waves is demonstrated experimentally and through numerical simulation. 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 side-attached 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. Three specific ring resonators systems are demonstrated: a simple single ring structure that acts as a comb filter, a single ring between two parallel waveguides that acts as an add-drop filter, and a sequential array of equally spaced rings that creates acoustic band gaps. 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 experiments are conducted in linear waveguides using an impulse response method. The ring resonators were created via 3D printing. Finite-element numerical simulations were conducted using COMSOL Multiphysics software. The experimental results were in good agreement with numerical models rendered in python and finite-element simulations.
Merry Young
The Sacred Bed Phenomenon: Which Sexual Attitudes Mediate the Association between Fundamentalism and Sex Guilt?
Faculty Mentors: Rebecca Oldham (Human Sciences)
Sexual scripting theory explains how social context can influence one’s feelings about sex and their sexual behaviors. For example, the sacred bed phenomenon addresses the influence religion has on those scripts through prescribing abstinence until marriage. When religious individuals have sex outside of marriage, they may experience sex guilt—a self-imposed punishment for violating “proper” sexual behavior. Understanding potential causes of sex guilt are important because it can diminish sexual desire and sexual satisfaction. This study explored the relationship between religious fundamentalism and sex guilt by examining which sexual attitudes mediated their association. Previous studies about religion and sexuality often overlook fundamentalism as a dimension of religiosity, which limits our knowledge of how it may be associated with sex guilt. This study combined two samples (N = 1,268)—one that recruited participants via social media from across the United States (n = 306) and the other which recruited college students from a southwestern university (n = 962). Participants completed an online survey measuring fundamentalism, several potential mediating sexual attitudes (i.e., sociosexuality, the importance of abstinence, communal sexual attitudes, and instrumental sexual attitudes), and guilt from engaging in premarital sex. Multiple regression analyses tested mediation effects. Results indicated that the more fundamentalist participants were, the more guilt they felt about having had premarital sex. Additionally, two of the four sexual attitudes tested were significant mediators of this association—sociosexuality and the importance of staying abstinent until marriage. Moreover, believing abstinence to be important was the strongest mediating sexual attitude. Consistent with the sacred bed phenomenon, this suggests that the relationship between fundamentalism and sex guilt is largely explained by how important abstinence was in their sexual scripts.
Anna Yuhas
Initiation and Cannabinoid Assessment of Trichomes on Industrial Hemp (Cannabis sativa)
Faculty Mentor: John Dubois (Biology)
Industrial hemp has been used throughout history for mechanical and medicinal uses, even today industrial hemp is proving to be a diverse provider for many areas of need in the modern world. In the textile industry, it is used as a cleaner alternative to cotton when it comes to the carbon footprint the industry is leaving behind on our planet. Recently, research has focused on the secondary metabolite-producing structure of the plant: the trichome. Trichomes on hemp plants are little hair-like structures located on the epidermis of the plant that produce secondary metabolites, specifically, cannabinoids and terpenoids. Medically important cannabinoids that have been found in these structures include Tetrahydrocannabinol (THC), Cannabinol (CBD), and at least 100 more cannabinoids. The objective of my research project is to produce industrial hemp secondary metabolite-producing trichomes under laboratory conditions and analyze the cannabinoid and terpenoid concentrations of five hemp varieties. The result of this experiment will help identify whether trichomes that produce sufficient cannabinoid and terpenoid concentrations can be produced in a petri dish long-term in the laboratory and be scalable to an industrial level rather than the alternative agriculturally produced trichomes from hemp plant’s flower bud.
Madeline Aadnes and Alexa Summersill
Understanding Undergraduate Biology Students Current Communication Habits About Climate Change
Faculty Mentors: Elizabeth Barnes (Biology)
Although climate change is considered one of the top threats to human health and prosperity by the World Health Organization, only 44% of people in the United States think humans are causing climate change (Leiserowitz, et al., 2014; IPCC, 2014). This is partly due to the difficulty scientists have effectively communicating climate change, as people often reject climate change due to political affiliation (Hart & Nisbet, 2011). Additionally, there is little research about teaching undergraduate students how to communicate effectively about important yet controversial biology topics, like climate change (Parker, 2018; Peter and Skorupa, 2021). Thus, we wanted to understand the current potential need for undergraduate student training on communicating about climate change. For this, we designed a study to characterize the current climate change communication from undergraduate biology students across the United States. For the study we designed a survey to collect general demographics, level of climate change knowledge, and frequency of and preparedness for communicating about climate change. We also interviewed 39 survey participants, in these interviews we delved deeper into personal experiences that the participants had communicating. Our preliminary findings indicate students avoid conversations about climate change with those with different beliefs from them, experience a lack of science communication training, and have a desire to learn more about science communication. As scientists in training, undergraduate students could benefit from being taught how to effectively communicate to people in and out of the scientific community about controversial scientific topics, especially climate change.
Allyson Campbell, Hannah Hudson, and Isabella Ramos
The Effects of Oxytocin and Atosiban Infusions into the Nucleus Accumbens on Social Reward in Male and Female Adult Mice
Faculty Mentor: Tiffany D. Rogers (Psychology)
While oxytocin is a neurotransmitter well-known for its role in social bonding, the specific circuitry through which these effects are mediated is unknown. Oxytocin receptors are found in dopaminergic nuclei which are also associated with social reward. Wehypothesize that social reward is mediated through oxytocin receptors in dopaminergic nuclei such as the nucleus accumbens. We aimed to increase or decrease activity in oxytocin receptors in the nucleus accumbens of awake, adult mice via direct pharmacological injection while measuring social reward by the social interaction conditioned place preference task (siCPP). The siCPP allows animals to choose bedding types that have been associated with social or isolated housing conditions to demonstrate their preference for social environment (social reward) or isolated environment. In separate groups of male and female mice, wewill infuse oxytocin, atosiban, or saline (control) into the nucleus accumbens during the behavior task. We expect to find that preference for bedding associated with social environments is increased following oxytocin receptor activation in the nucleus accumbens, and that preference for bedding associated with social environments is decreased following oxytocin receptor inhibition in the nucleus accumbens.We also expect to find sex effects such that oxytocin increases social reward in males more than females as females have a naturally higher level of endogenous oxytocin and may have a ceiling effect for activity at receptor sites. This research is innovative in its manipulation of oxytocin receptor activity in specific nuclei, as compared to systemic or whole brain changes, and in its alteration of oxytocin receptor activity in awake, behaving mice. The results of the study will further our understanding of the interaction of oxytocin and dopamine circuitry to account for changes in social reward.
Luke Gormsen and Kap Paull
READY to SOAR: A Pilot Outreach Program to Area High Schools
Faculty Mentor: Jamie Burriss (Office of Research and Sponsored Programs)
There are very few university programs that offer high school students the opportunity to experience undergraduate research prior to enrolling in higher education courses. The READY (Research Experience Activity Designed for Youth) to SOAR program at Middle Tennessee State University (MTSU) is being piloted this academic year and presents area high school students with an invitation to visit campus for an immersive research or creative activity experience. The goal of the program is to showcase MTSU’s undergraduate research opportunities to potential students through a one-day engagement event featuring activities such as site visits and tours of facilities (labs, dance/theatre/art studios, the farm), an educational panel featuring students and faculty mentors, and small group activities. Our research questions surrounding this experience include the following: What is their current perspective on the terms “research” or “creative activity”? What is their level of interest in pursuing research as a future undergraduate student? And finally, what is their intended area of study, if known? To answer these questions, we will administer a pre/post questionnaire to all participants. The results of this study will aid our team in programmatic planning for future READY to SOAR events, help us to better understand how high school students perceive undergraduate research, and their level of interest in becoming involved in undergraduate research.
Omar Ali
Species composition of forecsically-important flies associated with human decomposition at the Anthropology Research Facility of the University of Tennessee
Faculty mentor: Yanseung Jeong (Biology)
Forensic entomologists use insect evidence to reconstruct the circumstances of a crime scene at/around the time of event (e.g., estimation of time since death, determination of body movement). Forensically-important flies (FIF) are found in various stages of human decomposition. They lay eggs on a body and their maggots consume soft tissues, which significantly affect the pattern and rate of decomposition. Anthropology Research Facility (ARF, so-called the ‘Body Farm’) of the University of Tennessee has been used for human decomposition research for 40 years. Despite the important role of FIF in the process of human decomposition, it has not been fully investigated what species of FIF are present at the ARF. The purpose of this study is to investigate the seasonal and regional composition of FIF species at the ARF. This long-term study will serve as a basis to evaluate the effect of different FIF species on human decomposition. Flies were collected from 27 traps across the ARF twice a month between March 2018 – April 2019 (No flies were caught between December 2018 – March 2019). As of November 2019, morphological identification has been completed on 75% of the sample (2,513 out of 3,357 flies). Blowflies (Diptera: Calliphoridae) comprise approximately 94% of ID’ed flies. Out of 16 blowfly species identified, Phormia regina turned out to be most dominant in the Spring and Summer, but Lucilia coeruleiviridis was the most dominant species in the Fall. A significant change in the regional composition of FIF species by season was also noticed. Decomposition states of nearby bodies appeared to influence the regional distribution of the flies. Deeper knowledge about the species composition and activities of FIF at the ARF will enhance understanding on human decomposition and, eventually, contribute to a more accurate estimation of time since death in a crime scene.
Miquellie Bonner
Novel Method for the Forensic Dye Analysis by Direct Analysis in Real Time Mass Spectrometry
Faculty Mentors: Mengliang Zhang and Ngee Chong (Chemistry)
Direct Analysis in Real Time Ionization Source coupled with Mass Spectrometry (TD-DART-MS) has been used to identify the polymeric backbone structures of different textile materials such as cotton, nylon, polyester, cellulose triacetate, poly(propylene) and poly(acrylonitrile) in our lab. This analysis is very important to forensic trace analysis as examiners should perform a combination of methods to characterize fiber evidence, along with providing a complete and specific description of an item, rigorously assessing its uniqueness, and value as evidence. While methods such as Liquid chromatography-mass spectrometry (LC-MS) are currently applied, it can be laborious and time-consuming (e.g., about 1 hour). This study will propose and evaluate the unique TD-DART-MS method for the analysis of specifically dyes on differing fibers, which differs from past studies on fibers using TD-DART-MS. There are thousands of textile dyes which are often classified into different categories according to their application method and their chemical composition. This study will focus on the blue dyes from four categories including acid, basic, reactive, and vat blues which are commonly used in manufactured textiles and are more likely to have forensic value. Dye standards will be analyzed through TD-DART-MS and the characteristic ions will be identified. Fabric sheets, each dyed with an individual blue dye, will also be analyzed and compared to the standard and the method will be compared and validated by a standard Raman microscopic method. The expected results will show characteristic ions in the dyed fiber spectra that are consistent with the dye standards. The information collected will be useful to the study of fiber evidence in forensic science as the TD-DART-MS is not only a faster method, but can be a stand-alone method to provide a multidimensional chemical profile of textile fiber evidence.
Meredeth Bryson
Horizontal Positional Accuracy Assessment of 7.5’ Digital Geologic Maps of Part of the Nashville Dome, Central Tennessee
Faculty Mentor: Mark Abolins (Geosciences)
I seek to better-understand the horizontal positional accuracy of 7.5’ digital geologic maps in general. For example, it has been asserted that the positional accuracy of well-located contacts on some digital 7.5’ geologic maps exceeds 15 m. In this project, I quantitatively assessed the horizontal positional accuracy of digital geologic maps. To accomplish this, I began by georeferencing 48 published 7.5’ quadrangle geologic maps of Central Tennessee using the ArcGIS program. I was provided with scanned geologic maps. For each scanned map, I matched 10 marked intersections of latitude and longitude with the corresponding points on a USGS 7.5.’ digital raster graphic (DRG). I then applied an affine transformation to the scanned geologic map. The mean RMS horizontal positional error was 5.5 m, with a range of 3.1-9.4 m. This could be due to distortions in the scanned maps, and it could be due to human error in assigning matching points. Results will be used in ongoing efforts to quantify uncertainties in the estimated thicknesses of Central Tennessee sedimentary rock formations. The larger research goal is to understand the origin of thickness variations in carbonate strata deposited during Late Ordovician (~453 Ma) tectonic uplift of the Nashville Dome.
Shelby Cox
Assessment of Cannabinoid Levels in Successively Cloned Generations of Industrial Hemp (Cannabis sativa)
Faculty Mentor: John DuBois (Biology)
The business of industrial hemp (Cannabis sativa) has grown tremendously over the past decades, both in agriculture and pharmaceuticals because of its potential health benefits. Plant propagation using stem cuttings from stock plants has become the favorite method of growing hemp for farmers (Caplan et al. 2018). Recent studies have shown that plant propagation can lead to certain genetic changes known as somaclonal variations. This research was designed to test the effects of cloning hemp varieties (Cherry, Cherry Blossom, and Cherry x Workhorse) through plant propagation on cannabinoid production. Results showed significant differences in cannabinoid levels between clonal generations of each variety. The results of this study could be useful to farmers and hemp research centers such as the Tennessee Center for Botanical Medicine Research, and other hemp agricultural departments that must maintain cannabinoid consistency standards.
Jared Frazier
Blue Mars Initiative: Developing Linear Regression and Artificial Neural Network Models to Forecast Mesoscale Martian Weather Conditions
Faculty Mentor: David Butler (Computer Science)
At any given moment, a devastating cosmic event could wipe all life on Earth from existence. In combination with pressures humanity places on Earth’s biosphere, extinction may be inevitable.1 Going beyond our domain, further from the sun, and to the terrestrial planet Mars may be one way to reduce the possibility of human extinction.2 Despite this lofty goal, the hostile Martian weather conditions differ vastly from those on Earth, and the ability to predict those conditions would be invaluable for successful colonization. In particular, the extremely wide range of temperatures (20°C to -73°C) are a significant barrier to implementing human infrastructure.1 Traditional weather prediction techniques implemented on Earth such as numerical weather prediction (NWP) are extremely computationally intensive and are not always stable due to the volatile physical conditions of the Earth’s atmosphere. Additionally, NWP can not be easily transferred to predicting Martian weather.2,3 To overcome this barrier, supervised machine learning—a method that is resistant to the incomplete understanding of atmospheric conditions that introduces uncertainties to NWP—is ideal for the even less understood Martian atmosphere.4 Weather data for Mars’ Gale Crater was collected by NASA’s Curiosity Rover and is available through their Planetary Data System. Two types of machine learning algorithms will be implemented for the prediction of mean temperature using Curiosity’s data: linear regression and artificial neural networks. These machine learning paradigms were selected due to the ability of each to account for the mix of non-linear and linear responses in weather.5-7 For both models, ~3 Martian years of weather data will be used to predict ~1 year of test data. The mean and median absolute error for the prediction of mean temperature will be calculated and the models will be compared.
Jewel Galloway
Evaluation of Physiological Traits Expressed in vitro and Effects on Plant Growth by Bacillus Endophytes
Faculty Mentor: Stephen Wright (Biology)
Bacillus species are an important group of rhizobacteria that have been shown to enhance the growth of plants and protect against diseases caused by plant pathogens. This study investigated the mechanisms used by B. atrophaeus and B. thuringiensis to promote plant growth and explored their potential as biofertilizers and biocontrol agents for application in agriculture. Effects of each bacterial strain on the growth of Brassica rapa were evaluated under greenhouse conditions with sterile soil. Plant growth promotion traits including nitrogen fixation, phosphate solubilization, and siderophore production were assessed using in vitro microbiological techniques. Additionally, in vitro methods were used to evaluate antagonistic activities against two soil-borne pathogens, Fusarium oxysporum and Agrobacterium tumefaciens. To verify nitrogen fixation activity, the nitrogenase gene, nifH, was amplified by PCR. Plants inoculated with B. atrophaeus had significantly greater biomass and increased length compared to the control. In the in vitro assays, B. atrophaeus exhibited antimicrobial and nitrogen fixation activity while B. thuringiensis was positive for siderophore production. These bacteria could potentially be used as biofertilizers and biocontrol agents in conjunction with currently used agrochemicals to reduce the environmental costs associated with synthetic chemicals.
Jori Graeff
Sterol Composition of the Peridinioid Dinoflagellate Zooxanthella nutricula, a Symbiont of Polycystine Radiolarians: Implications for Symbiont-Derived Radiolarian Sterols and a Comparison to Sterols of other Dinophyceae
Faculty Mentor: Jeffrey Leblond (Biology)
Oral Presentation
Some dinoflagellates, such as Symbiodinium, are able to form symbiotic relationships with larger marine organisms. An important aspect of dinoflagellate symbiosis involves the exchange of lipids, namely sterols, from the symbiont to the host. Much research has explored the lipid biochemistry of the symbiotic relationship between cnidarians and Symbiodinium dinoflagellates. However, no research has addressed the sterol biochemistry of the symbiosis between radiolarians and dinoflagellates such as Zooxanthella nutricula. To this end, we have provided the first sterol characterization of Z. nutricula isolated from a spumellarian polycystine radiolarian. Lipids were extracted from cell cultures using a chloroform, methanol, and phosphate buffer system. Collected lipids were fractionated into component lipid classes using open column chromatography and solvents of varying polarity. Collected free and esterified sterols were saponified and derivatized to form trimethylsilyl ethers, and resulting sterol derivatives were analyzed using gas chromatography/mass spectrometry (GC/MS) with positive-ion electron impact (EI) ionization. Fifteen sterols and one steroidal ketone were observed where the major sterol identified was C27 22-dehydrocholesterol (comprising approximately 30% of the sterols), which does not tend to be a dominant sterol among dinoflagellates, including closely related peridinioid species in the genus Heterocapsa. However, in Z. nutricula, C30 dinosterol comprised about 20% of the sterols and C30 dinostanol comprised about 8% of the sterols. These sterols were identified with similar abundances in both Z. nutricula and Heterocapsa spp., thus indicating common sterols between closely related taxa. Major sterols of the distantly related genus Symbiodinium, a symbiont of foraminifera and cnidarians, have included C27 cholesterol and C30 gorgosterol, whereas in Z. nutricula these sterols were minor and absent, respectively. Our results indicate potentially different sterol pools available to cnidarian and radiolarian symbiont hosts during their respective relationships with symbiotic dinoflagellates.
Koda Hengstenberg
Exploration of Aurone System in Mercury Sensing
Faculty Mentor: Scott Handy (Chemistry)
Mercury remains one of the most toxic heavy metal pollutants today. Mercury finds its way into ecosystems through air, water, soil and many natural processes. For this reason, it is necessary in identifying mercury at a microscopic level; fast, reliable and safe techniques are vital for early detection. Some of the many symptoms from mercury poisoning include, loss of neurons with reactive proliferation of glial cells, microvacation, vascular congestion petechial hemorrhage and edema. With the effects ultimately leading to death, it is fundamental that detection is prioritized. In particular to aurones, they offer fast and predictable results while also negating the use of harmful UV-light because of the high photostabilities. It has been concluded that the aurone base could provide a source of a reactive alkene, capable of an oxymercuration reaction necessary in detection. Reacting with an alkene to form a cyclic mercury compound, the UV/Fluorescence properties are hypothesized to change, ultimately providing for an “ON-OFF” switch. The 4-hydroxyallylaurone showed great results when reacting with mercury in an aqueous environment. Shifts in fluorescence intensity provided an “ON-OFF” switch, but modifications to overall structure could increase the disparity in fluorescence intensity after mercuration.. Enhancing the specificity and sensitivity of the reaction with respect to fluorescence will create a simple detector molecule capable of detecting mercury ions present in concentrations lower than those deemed toxic by the USA Environmental Protection Agency (EPA) in safe drinking water (2.0 ppb).
Yostina Lamei
Effects of Dopamine Agonist and Antagonist on Social Behavior in Mice
Faculty Mentor: Tiffany D. Rogers (Psychology)
Dopamine (DA), a neurotransmitter, plays a role in motivation, learning, mating, and aggression in humans. The present study experimentally investigates the effects of DA agonist and antagonist on social behavior in male and female C57BL/6J mice. Subjects (N=60), aged 8-10 weeks, were randomly assigned to undergo DA agonist, antagonist, or saline intraperitoneal (i.p.) injections before being assigned to a social motivation task or a T-maze. Hand coding will be used for the social motivation task to record the following: time spent in the incentive zone (within 10 cm of the cage), time spent in the social approach of the subject to the stimulus mouse, time spent in avoidance of the stimulus mouse, number of times the incentive mouse rears, indicating anxiety. Hand coding will also be used in the T-maze to record the following: time spent in a nose to nose orientation, time spent in the social approach of the experimental mouse to the stimulus mouse, time spent in avoidance of the stimulus mouse, number of times experimental mouse bites, indicating aggression. Aggression is expected to be found in male mice treated with DA agonist and female mice pretreated with DA antagonist. Non-competitive social behavior is expected to be facilitated in male mice pretreated with DA antagonist and in female mice with DA agonist. Implications of these findings are discussed relative to DA’s role as an interacting factor with oxytocin.
Jake Maisano
Using fermentation to create environmentally friendly food packaging: Testing antioxidant properties of kefiran for use in plastic-free films
Faculty Mentor: Keely O'brien (Fermentation Science)
Introduction: Kefir grains, despite their name, are not a grain. They are, in fact,
living organisms composed of multiple microorganisms that, when added to milk, produce
a fermented beverage called kefir. This symbiotic culture of microbials include Lactobacilli,
Lactic streptoccoci, yeast, and acetic acid bacteria bound together in a self-generated
polysaccharide matrix. [1] The bacterial polysaccharide that can be extracted from
kefir grains and kefir is known as kefiran. This extracellular polysaccharide and
its’ components are formed from the multitude of microorganisms and several species
of Lactobacillus. [2]
The potential uses of a biopolymer formed from kefiran are many. Due to its antimicrobial,
antibacterial, and anti-inflammatory properties among others, kefiran is already being
explored for use in the medical field as topical antiseptics and in bandages for wounds.
[2] Another valuable attribute of this polysaccharide is that the film formed from
the extracted and purified kefiran is biodegradable and can be used as a substitute
for plastics in uses such as food packaging. [2]
The use of a biopolymer instead of a plastic material, such as those made from a petrochemical
base, not only are better for the environment, as they are biodegradable, but they
also reduce the use of energy and economic cost. [3]
Objective: The objective of this research is to test the antioxidant properties of
kefiran and to produce microbial polysaccharide films from kefir grains and kefir.
Methodology: Purified kefiran films will be thoroughly dried using three different
drying temperatures comprised of drying at freezing point, drying at room temperature,
and drying at an elevated temperature of 25 C and weighed. The kefiran will then
tested for antioxidant properties using a DPPH radical scavenging assay and a hydrogen
peroxide radical scavenging assay.
Autumn Martin
Fixed and Growth Beliefs about Different Ability Domains among College Student
Faculty Mentors: Tom Brinthaupt and Ryan Korstange (Psychology)
Oral Presentation
Mindset theory looks at how basic abilities are perceived and is very relevant to
the academic setting. Individuals can view abilities as either something that is innate
and unchangeable (fixed) or something that has the possibility of being developed
(growth). My research project expands the concept of mindset theory to look at not
only academics and social skills, but to consider a multitude of other domains (leadership
skills, athletics, and artistic abilities). I wanted to see if fixed or growth mindset
beliefs reflect a general trait that applies across multiple domains, or if there
could be differentiation depending upon the ability domain in question.
For this project, I manipulated Dweck’s 8-item mindset instrument (DMI) (P’Pool, 2012)
for each individual domain. Students (N= 209, 110women, 99 men) rated each domain
in terms how stable or changeable they believe it is. I wanted to see if there was
any potential differentiation in skill/ability beliefs across gender, grade level,
or ethnicity. Our results show that, overall, the domains seemed to correlate positively,
meaning that over the different domains, students are generally consistent in whether
they believe their skills or abilities are changeable or stable. We found slight,
but non-significant differences in beliefs based on gender. There was also some evidence
of differentiation in the domains, with students reporting higher levels of growth
beliefs in the intelligence and leadership domains compared to the athletic and artistic
domains. The domains that were chosen for this study are ones that a college student
could be presented with at some point during their college experience. Understanding
how students perceive themselves in those multiple domains can allow researchers to
see if mindset is a trait that is specific to a certain domain or if it extends to
their general perception of everything related to their college experiences.
Kylie Moe
The Endosymbiotic Bacterial Community of the Causative Agent of White-Nose Syndrome (Pseudogymnoascus destructans) of Bats.
Faculty Mentor: Donald Walker ( Biology)
Diseases caused by fungal pathogens have contributed to devasting and long-term consequences to wildlife, including extinction and economic impacts. These pathogens are notoriously difficult to control due to molecular and physiological similarities to their eukaryotic hosts. Most treatment options not only affect the fungal pathogen, but also negatively impact the host. Gaining a better understanding of the physiological and biological characteristics of fungal wildlife pathogens can provide a foundation for developing alternatives to traditional treatment applications. Pseudogymnoascus destructans (Pd), the causative agent of white-nose syndrome in bats, is currently threatening bat populations across North America. Our goal of this work was to characterize symbiotic and/or antagonistic biological relationships that Pd fungus might have with bacteria. The DNA from eighteen Pd isolates collected from eighteen tricolored bats (Perimyotis subflavus) was sequenced using two techniques, including Sanger and high-throughput sequencing. The fungal isolates were imaged using transmission and scanning electron microscopy and exhibited bacterial cells inside fungal hyphae. Using DNA sequence data, we identified a bacterial species in the genus Nocardia sp. as a potential endohyphal resident of the fungus. To understand physiological differences between Pd with and without endohyphal bacteria, all isolates were treated with antibiotics to effectively reduce Nocardia sp. abundance. Treatment groups were created using an antibiotic cocktail (treatment) and compared to wildtype isolates that received no antibiotic treatment. We then evaluated protease activity using skim milk agar for both treatment and wildtype groups. Growth rate statistically differed between groups and was higher in wildtype isolates. Currently, our results support the possibility of a symbiotic relationship between Pd and Nocardia sp. These results improve our understanding of the interactions between Pd and the bacteria that inhabit it, and may provide a potential target to counter the virulence of this fungal pathogen.
Gabriella S. Morin
Determining How the PINK1:Parkin Mitophagy Pathway Responds to Transient Mitochondrial Stress and How This is Affected By Disease Associated Mutations in Parkin
Faculty Mentor: David E. Nelson (Biology)
Mitophagy is a mitochondria-specific form of autophagy used by cells to remove damaged, dysfunctional mitochondria. The process serves to maintain the health of mitochondrial networks and prevent cell death via the intrinsic apoptotic pathway. The PINK1:Parkin mitophagy pathway is capable of identifying depolarized mitochondria with both proteins accumulating at the surface of these and cooperating to assemble phospho-polyubiquitin chains (ppUb) on outer mitochondrial membrane (OMM) proteins. These ppUb chains serve as docking sites for additional Parkin proteins and autophagy receptors that recruit the autophagic machinery to mitochondria. While previous studies have suggested that this process can be disrupted at its earliest stages by repolarization of the mitochondria, resulting in rapid degradation of PINK1 proteins, more recent work has shown that Parkin proteins are retained at the OMM for more than an hour after mitochondrial membrane potential has been restored. However, the molecular mechanism for this remains unclear. In this thesis, we test the hypothesis that Parkin proteins are retained after mitochondrial association though interaction with OMM ppUb proteins. This was performed by measuring colocalization of EYFP tagged wild type or an E3 ligase-Dead Parkin mutant (C431S) with a red fluorescent mitochondrial marker in cells treated with the mitochondrial depolarizing agent, CCCP, pre- and post-washout by live cell microscopy. Consistent with published data, we find that EYFP-Parkin is retained at mitochondria for at least one-hour post-repolarization. While a smaller fraction of EYFP-Parkin-C431S proteins were found to associate with mitochondria in CCCP-treated cells, consistent with our hypothesis, these were found to dissociate and return to the cytoplasm rapidly post-CCCP washout, indicating that ppUb has a role in Parkin retention post-mitochondrial repolarization.
Zachary Sanchez
Beliefs and Attitudes on Working with Older Adults Scale Development
Faculty Mentors: Shelley Moore and Amanda Flagg (Nursing)
The goal of this research project was originally to study why nursing students don’t
specialize in geriatrics – it is consistently ranked as one of the lowest populated
specialties for new grads. The previous literature review indicated the need for new
and better-developed scales, therefore this part of the research project was focused
on developing a scale we could then use to measure nursing students' attitudes, behaviors,
and knowledge concerning working with older adults. As the number of older Americans
grows, the lack of healthcare professionals that would work with these individuals
has become more and more relevant. Nurses are the best positioned to help fill this
void of clinicians as they are the largest group of healthcare professionals and can
be educated readily in the care of older adults.
After conducting a literature review, many of the articles recommended more longitudinal
studies, larger scales, and revision of previous scales. With that information, we
developed a 37 question scale using previous scales’ questions that we updated or
adding brand new questions we made in consultation with various literature. This scale’s
constructs contained: Control beliefs (factors that individuals perceive as being
present that may facilitate or impede the performance of their behavior); Attitudes
(the degree to which a person has a favorable or unfavorable evaluation of the behavior
of interest. It entails a consideration of the outcomes of performing the behavior);
Behavioral beliefs (the subjective probability that the behavior will produce a given
outcome or experience); Subjective norms (the belief about whether most people approve
or disapprove of the behavior); and Knowledge (which is objective information about
caring for older adults).
Luis Zuniga
Investigating Vertical Transmission of Microbial Symbionts in Marine Sponges
Faculty Mentor: Cole G. Easson (Biology)
Coral reefs present a paradox since these diverse ecosystems exist in oligotrophic environments. This diversity is in part possible because of the efficient recycling of essential nutrients facilitated by resident organisms and their microbiomes. The current study focuses on the sponges of marine coral reefs and their symbiotic microbiomes. Sponges and their symbionts play a role in the recycling of nutrients and help ensure productive energy flow, allowing coral reefs to thrive. Efforts have been made to identify the symbionts in marine sponges through the Earth Microbiome Project. However, it is difficult to tell which microbes are “true” symbionts, meaning they play an integral role in the survival of the sponge and are likely in association with the sponge larvae. We hypothesized that symbionts in these sponges are transferred vertically (adult to offspring), and or horizontally (from surrounding environments). To test this, we took three species of sponges (Iotrochota birotulata, Niphates erecta, Svenzea zeai), adult and larvae, and sequenced the V4 region of their 16S rRNA genes using next-generation Illumina sequencing. This experimental design allows us to observe which microbial taxa are present in both life stages. Our results suggest that symbiont transmission is species specific, which agrees with our current understanding of adult sponge microbiomes. Vertical transmission of some taxa was observed in all species, however only two (I. birotulata, S. zeai), showed significant differences between life stages. These differences suggest that a portion of the sponge’s symbionts are acquired horizontally. Conversely, data from N. erecta suggests vertical transmission, with few taxa exhibiting a shift between life stages. While this study only investigates three sponges, it provides important insight into microbial transmission among marine sponges on coral reefs. These insights, though specific to the collected species, help add to the overall knowledge of dynamic processes within marine coral reefs.
Dara Zwemer
Officer Workload and Officer-Involved Shootings of Unarmed Decedents From 2016-2017
Faculty Mentor: John Pennington (Psychology)
Two measures of police officer workload in the U.S. were created from archival data and used as potential predictors of the number of lethal officer-involved shootings of unarmed individuals (LOIS-Us) (N = 146) that occurred in 2016 and 2017. To create total crime and violent crime workload indices, the population size, number of employed officers, number of violent crimes, and number of property crimes was obtained for each municipality and state in which a LOIS-Us occurred. The present author hypothesized that states with more LOIS-Us would have higher total and violent crime workload values than states with fewer shootings; the author also predicted that both workload values would be higher in municipalities where shootings occurred, compared to those cities’ state-level workload measures. Unexpectedly, state total crime workload values were unrelated to LOIS-Us, and state violent crime workload values were negatively correlated with LOIS-Us. Similarly, municipalities with LOIS-Us had significantly lower total and violent workload values than the state in which the municipalities were located. These results may stem from officers in locations with lower workloads having less experience than officers in locations with higher workloads. In addition, more officers may respond to a single crime in municipalities with lower violent workload values. Future research that includes more recent cases may allow one to predict which U.S. municipalities may be more at risk for lethal OISs based on their total and violent workload indices.
Jillian Sherer and Amy Train
Flourescent Labels Based on the Aurone Scaffold: A Group Project
Faculty Mentor: Scott Handy (Chemistry)
Fluorescent labels can be used in many aspects of scientific research from bacterial
identification to protein component determination. However, many fluorescent labels
are wildly expensive and complex.1 Through the use of organic chemistry, fluorescent
labels that are smaller, simpler to produce, and less expensive can be synthesized
for future research. It is my intention to develop a fluorescent label that can be
used to identify thiol containing
proteins, enzymes, and amino acids through the use of a three-component compound with
a fluorescent label, color control side chain, and a benzofuranone linker. Aurones
are cyclic structures in the flavonoid family that often appear as bright yellow or
orange hues.2 These aurones can be modified to tune the absorption and fluorescent
spectra of the labels being produced through this research. A benzofuranone group
can serve as a
linkage between an activated aurone that gives fluorescence and a reactive label that
can bind to a thiol containing amino acid, making it fluoresce. Once
made, there is considerable potential for future research involving this synthesized
label as well as other similar labels by exploring variation of the color control
fragment and ultimately application to real biological questions. Beyond labeling
and tracking labeled compounds in a whole cell system, these fluorescent labels can
also be applied to research techniques such as FRET (Förster resonance energy transfer)
in order to determine longer distances within and between protein subunits that are
otherwise difficult to determine.
Radina Porashka and Nathan Smith
Survey of Mosquito Predatory Ciliate Lambornella for Potential Biological Control
Faculty Mentor: Anthony Farone (Biology)
Mosquitoes are known for being vectors of transmission of various diseases, including malaria, Zika virus, West Nile virus, and yellow fever. With the current concern over mosquito-borne viral infections, it is worth revisiting the possibility of growing the ciliated protozoan, Lambornella, for biological control applications. The purpose of this study was to identify, isolate, and culture Lambornella clarki to utilize as a potential biological mosquito control. The ciliated protozoan Lambornella clarki and other Lambornella species are known to target mosquitoes, specifically mosquito larvae. Lambornella parasitize mosquito larvae by attaching to the exterior of the larval cuticle, then form a hole in the cuticle and enter the hemocoel, thereby invading the tissue and killing the larva. The specificity of Lambornella to target mosquitoes and its high infectivity rate for the larvae have led to the suggestion that the organism could be used for the biological control of mosquito populations. In order to achieve these results, we collected water samples locally and from Florida and California. Ciliated protozoa were isolated by a variety of techniques and cultured in various media. DNA from isolates was amplified using the PCR to confirm the identity of the ciliate. Out of 37 samples, 19 of them were identified as potential Lambornella candidates. Potential Lambornella candidates will be tested for their ability to grow to large numbers by culture. Identifying appropriate culture media and conditions will be vital to use Lambornella as a natural biological control instead of current potentially hazardous chemical control agents.
MTSU's 2020 Selected Participants
Omar Ali
Species composition of forensically-important flies associated with human decomposition at the Anthropology Research Facility of the University of Tennessee
Faculty mentor: Yanseung Jeong (Biology)
Forensic entomologists use insect evidence to reconstruct the circumstances of a crime
scene at/around the time of event (e.g., estimation of time since death, determination
of body movement). Forensically-important flies (FIF) are found in various stages
of human decomposition. They lay eggs on a body and their maggots consume soft tissues,
which significantly affect the pattern and rate of decomposition. The Anthropology
Research Facility (ARF), the so-called “Body Farm,” at the University of Tennessee
has been used for human decomposition research for 40 years. Despite the important
role of FIF in the process of human decomposition, it has not been fully investigated
what species of FIF are present at the ARF. The purpose of this study is to investigate
the seasonal and regional composition of FIF species at the ARF. This long-term study
will serve as a basis to evaluate the effect of different FIF species on human decomposition.
Flies were collected from 27 traps across the ARF twice a month between March 2018
and April 2019 (No flies were caught between December 2018 and March 2019). As of
November 2019, morphological identification has been completed on 75% of the sample
(2,513 out of 3,357 flies). Blowflies (Diptera: Calliphoridae) comprise approximately
94% of ID’ed flies. Out of 16 blowfly species identified, Phormia regina turned out
to be most dominant in the spring and summer, but Lucilia coeruleiviridis was the
most dominant species in the fall. A significant change in the regional composition
of FIF species by season was also noticed. Decomposition states of nearby bodies appeared
to influence the regional distribution of the flies. Deeper knowledge about the species
composition and activities of FIF at the ARF will enhance understanding on human decomposition
and, eventually, contribute to a more accurate estimation of time since death in a
crime scene.
Aric Moilanen
Disordered Electron Systems: A Local Quantum Cluster Model
Faculty Mentor: Hanna Terletska (Physics and Astronomy)
One essential factor in the modeling of quantum electron systems is the presence of disorder. Disorder is a ubiquitous feature of all real materials that can have extremely profound effects on the structural and transport properties of said materials. Disorder can even cause phase transitions in materials, such as the metal-insulator transition brought about by disorder-driven Anderson localization. We use quantum cluster typical medium theory (QC-TMT) to identify when these transitions occur. QC-TMT is an effective medium theory, which employs the typical density of states rather than the average density of states, to distinguish between metal and insulator. As an ad hoc approximation, TMT is extremely dependent on using a good ansatz. However, if attempting to model a complex system, such as an interacting multi-orbital system, the use of a full cluster momentum K-dependent non-local ansatz makes computation nearly impossible. We tested the validity of using a simplified local-only ansatz for calculating typical density of states, which would make the simulation of such systems viable. The local ansatz neglects all non-local inter-site (K-dependent) effects in typical density of states and only considers local (on-site) density of electrons. In our testing, we have found that the local-only ansatz agrees with the full K-dependent ansatz at disorder values close to the transition. Furthermore, we have established for what criteria, including disorder ranges, this local-only approximation remains valid.
Gabriella S. Morin
Determining How Disease-Associated Mutations Affect the Dynamics of Mitochondrial Recruitment and Loss of the Mitophagy Regulator, Parkin Faculty
Faculty Mentor: David E. Nelson (Biology)
The PINK1:Parkin mitophagy pathway is a mitochondria-specific form of autophagy that
destroys damaged, dysfunctional mitochondria within cells, thereby maintaining the
health and integrity of mitochondrial networks. Loss of function mutations in the
genes encoding PINK1 and Parkin, the principal regulators of the pathway, are associated
with the neurodegenerative disorder Parkinson’s disease (PD). At polarized mitochondria,
PINK1 is rapidly processed and degraded. However, damage-induced loss of mitochondrial
membrane polarization (MMP) promotes stabilization of PINK1 on the outer mitochondrial
membrane (OMM), recruiting cytosolic Parkin to form phospho-polyubiquitin chains (ppUb)
on OMM substrates, which serve as binding sites for autophagy receptors. If loss of
MMP is transient, the process of mitophagy can be interrupted and PINK1 will be rapidly
degraded within a matter of seconds or minutes. However, we have observed that Parkin
often persists at the OMM for many minutes after restoration of MMP. We hypothesize
that the slow degradation of ppUb chains after repolarization is responsible for Parkin
retention.
To test this, we have reconstituted Parkin-null HeLa cells with EYFP-tagged wild type
Parkin or a variety of Parkin mutants including the E3 ligase dead mutant R275W, which
is recruited with the same kinetics as WT Parkin post loss of MMP. We show that after
restoration of MMP, R275W dissociates from the OMM more rapidly than WT Parkin. This
is consistent with the hypothesis that ppUb chains are required for Parkin retention
at the mitochondria following repolarization.
Jared Frazier
Practical Investigation of Direct Analysis in Real Time Mass Spectrometry for Fast Screening of Explosives
Faculty Mentor: Mengliang Zhang(Chemistry)
While the direct analysis in real-time (DART) ionization source coupled with mass
spectrometry (MS) is viable for the screening of trace explosives, previous methods
require larger amounts of explosive residue for positive identification and are limited
by signal suppressing effects of matrices. This work demonstrates novel methods using
DART-MS for the high-throughput and sensitive detection of 19 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,
which is critical for decreasing the limit of detection for deadly explosives and
thereby reducing the likelihood of false negatives. 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.
The effects of substrates on signal suppression as well as limits of detection for
different explosives were evaluated. Notably, the high profile explosive hexamethylene
triperoxide diamine, used in 2016 New York bombings, could be detected more sensitively
than previously. Further, it was found
that representative explosives from each category could be detected with nanogram
sensitivity and in less than 10 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 (Agriculture)
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 over recent years, 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 tea 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.
Kaitlyn Berry
Mismatch Negativity Responses to English Vowel Sounds During an Audiovisual Oddball Task
Faculty Mentors: Emily Farris, Tim Odegard (Psychology)
This study explored the automaticity of grapheme-phoneme correspondences. Past research
has investigated this multimodal integration using an audiovisual oddball paradigm.
For this paradigm, a standard stimulus is presented over multiple trials, and an infrequent
deviant oddball occurs rarely. Electroencephalogram (EEG) recordings captured during
this task reveal a greater negative deflection following the presentation of a deviant
compared to the standard. This negative component is called the mismatch negativity
(MMN), and it is thought to reflect a violation of representations in working memory.
Prior research has observed differences in MMN to
occur across individuals who vary in age or reading skill proficiency. Much of the
existing research explored languages where phonemes map to a restricted number of
graphemes. In contrast, less research has been conducted in more orthographically
complex languages. In English in particular, vowel phonemes map to numerous graphemes.
Method: In the current study, undergraduate students completed an audiovisual oddball
task where grapheme “a” was presented with either short a (standard), short o (deviant
1), or schwa (deviant 2). Outside of the experimental context, all three phonemes
correspond to grapheme “a,” yet they differ in the extent to which they may correspond
with additional graphemes. It was hypothesized these differences in linguistic features
of the chosen vowel sounds would modulate observed MMN responses. Results: Results
indicate the MMN was distributed largely in the frontocentral areas of the brain for
both deviant phonemes as expected, with more topographically widespread findings observed
for deviant 2 (schwa). Furthermore, presentation of the schwa sound, which occurs
with a wide variety of letter patterns, was associated with a greater negativity than
the short o deviant. Conclusions: These data suggest statistical features of the relationship
vowels have with graphemes can modulate the automaticity of the associative response
evoked by the presentation of a grapheme.
Robyn Sessler
If the Model Fits: A Factor Analysis of the Five-Facet Mindfulness Questionnaire
Faculty Mentor: Cameron Gordon (Psychology)
Over the last several decades, mindfulness has become a very popular topic in psychology. Mindfulness, defined as present moment awareness and curiosity, has been shown to improve health and well-being through a variety of mindfulness-based interventions. The Five-Facet Mindfulness Questionnaire (FFMQ) has become a popular measure for mindfulness, as it conceptualizes mindfulness into five factors: Observing, Describing, Acting with Awareness, Nonreactivity to Inner Experience, and Nonjudgement to Inner Experience. Over the last several years, several studies have investigated how the five-factor model fits different samples with different demographics, specifically community versus clinical samples. The literature shows inconsistency over whether the five-factor model fits different samples with both adequate and inadequate fit reported for community and clinical samples. Therefore, this study sought to replicate these studies in order to determine if the five-factor model adequately fits a community sample (N = 211). Given previous research, several confirmatory factor analyses (CFA) were run: the original five-factor model, a five-factor hierarchical model with total mindfulness as an overall construct, four-factor hierarchical and non-hierarchical models excluding Observe, a facet known to behave differently in meditators versus non-mediators, and a six-factor model that split Acting with Awareness into two separate factors, in line with previous literature. All of the models demonstrated poor fit for the data (all RMSEA <0.07, indicating fair fit; however CFI < 0.90 and NNFI < 0.90, indicating poor fit). These results suggest that the five-factor model may not adequately fit this community sample, despite sufficient item loadings onto each respective factor. Given the inconsistency in the literature and that some researchers suggest conceptualizing mindfulness in fewer or additional factors, future work is necessary to measure different aspects of mindfulness in a consistent, meaningful way.
Autumn Martin
Fixed and Growth Beliefs about Different Ability Domains among College Students
Faculty Mentors: Tom Brinthaupt, Ryan Korstange (Psychology)
Mindset theory looks at how basic abilities are perceived and is very relevant to
the academic setting. Individuals can view abilities as either something that are
innate and unchangeable (fixed) or something that have the possibility of being developed
(growth). My research project expands the concept of mindset theory to look at not
only academics and social skills, but also to consider a multitude of other domains
(leadership skills, athletics, and artistic abilities).
I wanted to see if fixed or growth mindset beliefs reflect a general trait that applies
across multiple domains, or if there could be differentiation depending upon the ability
domain in question.
For this project, I manipulated Dweck’s eight-item mindset instrument (DMI) (P’Pool,
2012) for each individual domain. Students (N=209, 110 women, 99 men) rated each domain
in terms how stable or changeable they believe it is. I wanted to see if there was
any potential differentiation in skill/ability beliefs across gender, grade level,
or ethnicity. Our results show that, overall, the domains seemed to correlate positively,
meaning that over the different domains, students are generally consistent in whether
they believe their skills or abilities are changeable or stable. We found slight,
but non-significant, differences in beliefs based on gender. There was also some evidence
of differentiation in the domains, with students reporting higher levels of growth
beliefs in the intelligence and leadership domains compared to the athletic and artistic
domains.
The domains that were chosen for this study are ones
that a college student could be presented with at some point during their college
experience. Understanding how students perceive themselves in those multiple domains
can allow researchers to see if mindset is a trait that is specific to a certain domain
or if it extends to their general perception of everything related to their college
experiences.
Sara Moore and Rebekkah Riley
Inducing Somatic Embryogenesis in Grape (Vitis aestivalis “Norton/ Cynthiana”) Tissue Callus Derived from Ovary and Anther Explants
Faculty Mentor: John DuBois (Biology and University Honors)
The grape plant Vitis aestivalis “Norton/Cynthiana” is known for its hearty nature and low maintenance. However, this grape is also known for its poor propagation. Plant tissue culture is one method that has been used to propagate other recalcitrant species. The first goal of this research was to propagate undifferentiated cell growth, or callus, from anther and ovary tissues of immature flower buds. Callus growth was successfully achieved using a Lloyd and McCown basal nutrient tissue culture media. Healthy callus tissue was quickly created from the ovary tissue, whereas callus was not immediately successful from the anther tissue. Anther explant tissues had to remain on the media for several weeks longer than expected before the callus began to grow. The second goal of this project is to successfully generate somatic embryogenesis from the callus. Both the anther and ovary callus are being placed on embryogenic tissue culture media in order to promote embryogenesis. As Vitis aestivalis is not easily propagated, the embryogenic tissue media must be carefully made and adjusted to find the exact mix of cytokinin and auxin concentrations that will generate embryogenesis. Somatic embryogenesis in Vitis aestivalis has been attempted using callus generated from leaf explant tissue, but to date has had no success. The use of floral tissues has shown some success in other grape species. Successful completion of these goals would allow for plantlet production, and ultimately, reintroduction of this species into vineyards as a fungal endophyte free plant.
Radina Porashka, Mary Parsley, Sauleen Shamdeen, and Nathan Smith
Survey of Mosquito Predatory Ciliate LamborLily Medleynella for Potential Biological Control
Faculty Mentor: Anthony Farone (Biology)
Mosquitoes are known for being vectors of transmission of various diseases, including malaria, Zika virus, West Nile virus, and yellow fever. With the current concern over mosquito-borne viral infections, it is worth revisiting the possibility of growing the ciliated protozoan, Lambornella, for biological control applications. The purpose of this study was to identify, isolate, and culture Lambornella clarki to utilize as a potential biological mosquito control. The ciliated protozoan Lambornella clarki and other Lambornella species are known to target mosquitoes, specifically mosquito larvae. Lambornella parasitize mosquito larvae by attaching to the exterior of the larval cuticle, then form a hole in the cuticle and enter the hemocoel, thereby invading the tissue and killing the larva. The specificity of Lambornella to target mosquitoes and its high infectivity rate for the larvae have led to the suggestion that the organism could be used for the biological control of mosquito populations. In order to achieve these results, we collected water samples locally and from Florida and California. Ciliated protozoa were isolated by a variety of techniques and cultured in various media. DNA from isolates was amplified using the PCR to confirm the identity of the ciliate. Out of 37 samples, 19 of them were identified as potential Lambornella candidates. Potential Lambornella candidates will be tested for their ability to grow to large numbers by culture. Identifying appropriate culture media and conditions will be vital to use Lambornella as a natural biological control instead of current potentially hazardous chemical control agents.
