National Conference on Undergraduate Research (NCUR) 2021 Presenters

The 2021 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 2021 Selected Participants

Omar Ali, NCUR Presenter

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)

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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, NCUR Presenter

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)

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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

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)

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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, NCUR Presenter

Shelby Cox 

Assessment of Cannabinoid Levels in Successively Cloned Generations of Industrial Hemp (Cannabis sativa)

Faculty Mentor: John DuBois (Biology)

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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, NCUR Presenter

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)

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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, NCUR Presenter

Jewel Galloway

Evaluation of Physiological Traits Expressed in vitro and Effects on Plant Growth by Bacillus Endophytes

Faculty Mentor: Stephen Wright (Biology)

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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, NCUR Presenter

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, NCUR Presenter

Koda Hengstenberg

Exploration of Aurone System in Mercury Sensing

Faculty Mentor: Scott Handy (Chemistry)

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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, NCUR Presenter

Yostina Lamei

Effects of Dopamine Agonist and Antagonist on Social Behavior in Mice

Faculty Mentor: Tiffany D. Rogers (Psychology)

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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, NCUR Presenter

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)

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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, NCUR Presenter

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, NCUR Presenter

Kylie Moe

The Endosymbiotic Bacterial Community of the Causative Agent of White-Nose Syndrome (Pseudogymnoascus destructans) of Bats.

Faculty Mentor: Donald Walker ( Biology)

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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 Morin, NCUR Presenter

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)

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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, NCUR Presenter

Zachary Sanchez

Beliefs and Attitudes on Working with Older Adults Scale Development

Faculty Mentors: Shelley Moore and Amanda Flagg (Nursing)

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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, NCUR Presenter

Luis Zuniga

Investigating Vertical Transmission of Microbial Symbionts in Marine Sponges

Faculty Mentor: Cole G. Easson (Biology)

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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, NCUR Presenter

Dara Zwemer

Officer Workload and Officer-Involved Shootings of Unarmed Decedents From 2016-2017​

Faculty Mentor: John Pennington (Psychology)

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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, NCUR Presenter Amy Train, NCUR Presenter  

Jillian Sherer and Amy Train

Flourescent Labels Based on the Aurone Scaffold: A Group Project

Faculty Mentor: Scott Handy (Chemistry)

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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, NCUR Presenter   Nathan Smith, NCUR Presenter

Radina Porashka and Nathan Smith 

Survey of Mosquito Predatory Ciliate Lambornella for Potential Biological Control

Faculty Mentor: Anthony Farone (Biology)

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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.

2020 NCUR Presenters


MTSU's 2020 Selected Participants

Omar Ali, NCUR Presenter

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)

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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, NCUR Presenter

Aric Moilanen

Disordered Electron Systems: A Local Quantum Cluster Model

Faculty Mentor: Hanna Terletska (Physics and Astronomy)

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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 Morin, NCUR Presenter

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)

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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, NCUR Presenter

Jared Frazier

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

Faculty Mentor: Mengliang Zhang(Chemistry)

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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, NCUR Presenter

Kayley Stallings

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

Faculty Mentor: Keely O'Brien (Agriculture)

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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, NCUR Presenter

Kaitlyn Berry 

Mismatch Negativity Responses to English Vowel Sounds During an Audiovisual Oddball Task

Faculty Mentors: Emily Farris, Tim Odegard (Psychology)

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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, NCUR Presenter

Robyn Sessler

If the Model Fits: A Factor Analysis of the Five-Facet Mindfulness Questionnaire

Faculty Mentor: Cameron Gordon (Psychology)

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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, NCUR Presenter

Autumn Martin

Fixed and Growth Beliefs about Different Ability Domains among College Students

Faculty Mentors: Tom Brinthaupt,  Ryan Korstange (Psychology)

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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, NCUR Presenter Rebekkah Riley, NCUR Presenter

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)

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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, NCUR Presenter Mary Parsley, NCUR Presenter Sauleen Shamdeen, NCUR Presenter Nathan Smith, NCUR Presenter

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)

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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.

 

 

 

 

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