Recent Submissions

  • Xenophobia in Rome and how it affected the early Christians

    Dowling, Abigail; Maylock, Nicholas (2021)
    One thing that everyone believes they know about ancient Rome is that the Christians faced persecution during this time. The treatment, or mistreatment, of the early Christians stems from a larger wave of xenophobia occurring in Rome in and around the first century. Remnants of this wave are present in the writings of the time, despite the common conception that once the Romans conquered a people, those people would be effortlessly absorbed by the Empire. This common misconception is spurred on by the Pax Romana, or Roman Peace, a term referring to the time of relative peace under the Roman Empire. The peace was held with military control and taxation of the Roman territories. Despite being at peace, Roman citizens, especially the ones living in the city of Rome, thought of themselves as better than the provincial citizens and outsiders. This Roman Xenophobia encapsulated dislike not just towards foreign groups, but also foreign ideologies. This paper will explore how xenophobia in Rome affected different groups, and where it was present in literary works. In addition, it will take a look at Christianity as seen by the Romans and show how it falls into the category of xenophobia and not religious persecution.
  • Trust and Perceptions of Autonomous Vehicles in Latin America

    Saravia, Antonio; Marroquin, Andres; Sadd, Luke (2021)
    Beliefs or perceptions about new technologies can affect their adoption and impact on economic progress. In this research project we examine if horizontal or interpersonal trust is associated with positive perceptions of autonomous vehicles (AVs). Using a representative survey from Latin America, we find that that is, indeed, the case for that region. We also find that individuals who are male, favor globalization, support foreign investment, and approve of democracy are more likely to perceive AVs positively. Our results are consistent with the literature on the ethics of artificial intelligence claiming that the factors that determine horizontal trust can be mapped into factors that determine trust in automation and AVs.
  • NGOs in Haiti: How Greed Feasts on the Country of Haiti

    Bennett, Stephanie; Bartlett, Emily (2021)
    This paper will examine the effects of foreign non-governmental organizations (NGOs) in Haiti. After the earthquake in 2010, there was a spike in the number of NGOs in Haiti, and many of those NGOs remain in Haiti even a decade after the natural disaster. NGOs have a strong influence over the lives of many Haitians, and many NGOs profit a great deal from their presence in Haiti. In order to examine how NGOs created such a strong foothold in Haiti, this paper will analyze Haiti�s history and the racist narrative of Haiti that �more developed� countries use to keep Haiti under their control. Next, this paper will examine specific NGOs such as Fonkoze and Partners In Health in order to understand why they came to Haiti, how they operate, and why they are still in Haiti after so long. By examining the legacy of foreign involvement in Haiti, as well as the influence of NGOs currently in Haiti, this paper seeks to understand the presence of NGOs in Haiti and offer a replacement of NGOs with Haitian-led initiatives.
  • Small Drug Molecules that Resemble Bacterial Signaling Molecules Act as Competitive Inhibitors with Intramolecular Communication Signals at Bacterial Receptor Sites

    Goode, David; Hensel, Linda; Kaimari, Abdulraheem; Malik, Samad; Patel, Prachi (2021)
    Contemporary studies have discovered that bacteria are multilingual, having both intraspecies and interspecies communication capabilities. Through quorum sensing, bacteria quantify their density and unanimously agree on carrying out a certain response (Bassler 2009). Biofilms are virulence factors that form once a bacterial quorum is reached within the host, preventing the host�s immune system from detecting and ultimately eradicating these pathogenic bacteria (Hensel 2020). This study tests certain drugs that could potentially prevent successful bacterial communication, as biofilms impact various industries including medicine, dentistry, and agriculture for years (Urry et al. 2017). The Crystal Violet assays reveal that Glu-8, Gly-8, Gly-30, and Sar-6 drugs had 84.84, 71.48, 62.48, and 58.23 average percent inhibitions in B. subtilis respectively. Glu-8 had 37.20 average percent biofilm inhibition in S. mutans, while Glu-8 in S. aureus was a major biofilm accelerator in the second trial (-31.63%) and inhibitor in the first (29.33%). None of the drugs demonstrated biofilm inhibition in the Congo Red assays. Similarly, none of the tested drugs demonstrated any bacteriostatic effects when added to their bacterial cultures in the Disk Diffusion plates. Likewise, none of the drugs in the Use-Dilution plates were bactericidal. Although Glu-8 in B. subtilis and S. mutans and Sar-6 in B. subtilis were consistent biofilm inhibitors, further Crystal Violet trials are necessary to determine their biofilm inhibition ranges, and to determine whether Glu-8 is an inhibitor or accelerator in S. aureus. Accordingly, the combination of Glycine (Gly) and o-Bromobenzoic acid (bromine attached to the benzene functional group) resulted in an effective biofilm inhibitor without any bacteriostatic or bactericidal effects. Therefore, Glu-69 and Gly-69 should be tested in the future to analyze the effect of two bromines on a benzene ring. By doing so, certain functional groups could be characterized by their success in mimicking bacterial signals and ultimately inhibiting intraspecies communication. The aim is also to test Gly-10 to confirm that bromine attached to a benzene ring in the drug is what causes successful mimicking of endogenous intraspecific ligands, and not the bromine alone.
  • The Impact of COVID-19 on Entrepreneurial Well-Being: Examining Psychological Capital

    Forrester, Juanita; Waldman, Isaac (2021)
    For entrepreneurs, the global pandemic that swept through the United States in 2020 introduced a new set of uncertainties and challenges. Stay-at-home restrictions took a toll on the economy, and a drastic decline in consumer spending forced many small businesses to shut down or pivot to adapt to a changing society. This study seeks to examine the impact of COVID-19 on the subjective well-being of surviving entrepreneurs across several sectors of business. We focus specifically on the role of psychological capital, which includes hope, resilience, optimism, and efficacy, as a personal asset that supports entrepreneurs� overall well-being in the face of ongoing obstacles. We predict that for entrepreneurs, psychological capital mediates the relationship between pandemic-related stressors and subjective well-being. We explore these predictions by surveying a sample of local entrepreneurs. Preliminary results and implications for entrepreneurial well-being will be discussed.
  • Strategic Marketing for Small Businesses

    Rynarzewska, Ania; Drummond, Sarah (2021)
    With the social media boom, businesses began investing into social media and influencer advertising. The coronavirus pandemic accelerated and amplified the need for successful online campaigns. Covid-19 has led to closures of businesses, lower incomes, and greater safety measures. Consumers shopped more online and built new online habits. Small businesses have been combating this by moving their main advertising focus to the internet through social media or websites. Many forms of online advertising include paid promotions, surveys, daily posts, livestreams, and influencer marketing. Which of these forms of promotion is the most effective for small businesses during and potentially after the pandemic? This study analyzed a real business during the pandemic and its various online marketing strategies for increasing key business metrics. Findings are not only relevant to academic theory but most importantly helpful to small businesses in their decision making contributing to business survival.
  • German-Americans During the Kulturkampf: The Influence of German Affairs in the United States

    Dowling, Abigail; Flammer, William (2021)
    When Germans immigrated to the United States after 1848, many came as refugees of the same year’s failed revolt. These Forty-Eighters were a vocal and elite minority of the total German-American population. As expected of immigrants, many German-Americans decided to migrate predominately because of economic opportunities but religion, politics, and family dynamics also played influential roles in how individuals made their decisions to leave the old world. These Immigrants brought with them the political trends of Germany, both the liberal and the conservative. German-American responses to the Unification of Germany and the Kulturkampf help us understand their own identity and their place in America. Ultimately, Americans in this period––both Germanic and Anglo in origin––were attempting to define what makes someone a true American citizen. Through the use of primary sources consisting of Newspapers and immigrant letters, this paper attempts to articulate German-American immigrants’ opinions besides those of the well-documented Forty-Eighters.
  • Analysis of a deletion library screen of the yeast Saccharomyces cerevisiae using Gene Ontology, protein-protein interaction, and metabolic pathway data

    Wiles, Amy; Graham, Joseph; Simmons, Sean; Gazan, Ethan; Cobb, David (2021)
    Saccharomyces cerevisiae (baker's yeast) is a commonly used eukaryotic model organism particularly suited to genomic and metabolic study. We hope to identify genes novel to sulfur and nitrogen metabolism. In previous experiments from this lab, a gene deletion library of 5,132 yeast strains was screened to identify genes necessary for growth in the absence of sulfur or nitrogen. If a gene were deleted and no growth were observed, this gene was determined to be important for allowing proliferation in the nutrient-limited environments and flagged as a hit. In this project, a one way ANOVA test was performed on the screen using R using the BiocManager library and limma package. The results of the ANOVA test were joined in MySQL with Gene Ontology (FuncAssociate), protein-protein interaction (InterPro), and metabolic/signaling pathway (KEGG) data obtained from Ensembl. Here we use analysis of these three types of data to distinguish common themes among the genes identified as hits.
  • Comparison of Particle Deposition of E-Cigarette with Traditional Tobacco Cigarette Smoke

    Hyun, Sinjae; Turner, Emily; Holloway, Madison; Kight, Olivia; Jung, Michelle; Spalding, Sarah (2021)
    Comparison of Particle Deposition of E-Cigarette with Traditional Tobacco Cigarette Smoke Emily Turner, Madison Holloway, Michelle Jung, Olivia Kight, Gunhee Lee, Sarah Spalding, Sinjae Hyun, PhD. Biomedical Engineering Department, Mercer University Introduction: Over the past twenty years, vaping has become popular among young people with more than 3.6 million middle and high schoolers using e-cigarettes in 2020. (1) The purpose of this study was to evaluate the differences in particle characteristics and deposition of e-cigarette aerosol versus that of traditional tobacco smoke. Particle diameter and concentration for different air flow rates and flavor pods were tested on e-cigarettes to establish control conditions for the following trials. The data was used to simulate inhalation of e-cigarettes and traditional tobacco cigarette aerosols that had undergone the same testing process. The Multiple-Path Particle Dosimetry (MPPD) was used to analyze various morphological models of human airways. Materials and Methods: An e-cigarette cartridge was attached to a power supply of 3.7 V, as well as two branches of tubing on the other end. One of the branches was connected to a vacuum pump to imitate inhalation; the other was attached to a Wide-Range Particle Spectrometer (WPS), with an intake rate of 1 LPM, to measure the particle sizes ranging from 10 nm to 10 microns. Once testing for e-cigarettes was completed, we altered the setup to accommodate traditional tobacco cigarettes. An airtight enclosure was made, with an adapter to allow a tube to be directly attached to the cigarette. The data was analyzed using MPPD software to determine if the aerosol deposition changes for 6 different lung airway morphological models. The stochastic 12 bpm model was chosen as a general model representing an average 40-year male. Its predecessor, the Yeh Schum 5-lobe model, was also tested as a lung model. The six models tested were the stochastic model for normal breathing (12 bpm); the stochastic model with lowered breathing frequency (6 bpm) mimicking breathing impairment; the stochastic model with elevated breathing frequency (25 bpm) mimicking lung disease; the Yeh Schum 5-lobe model; and two age-specific (14 and 21 years) 5-lobe models. Statistical analyses demonstrated no significant difference between the means of the six models; further analysis showed that Age 21, Stochastic 25 bpm, and Stochastic 6 bpm models were different in pulmonary deposition, and Age 14, Age 21, and Stochastic 6 bpm models were different in whole lung deposition. Results: The concentration of particles was observed by a measure of density in grams per cubic centimeter for different ranges of particle diameters. For the diameter range 1.08x10^-2 to 9.5 ?m, the e-cigarette aerosol was produced by heating the liquid in the cartridge, which produced a concentration range of 5x10^-17 to 6x10^-9 g/cc. For the diameter range 0.01 to 9.6 ?m the smoke produced by the tobacco cigarette had a concentration range of 0 to 7x10^-8 g/cc. The particle diameter ranges analyzed were comparable, but the e-cigarette produced much smaller particle concentration ranges (5x10^-17 to 6x10^-9 << 0 to7x10^-8). Of the total measurements, tobacco cigarettes deposit particles at a rate of 185% higher than e-cigarettes. E-cigarette (stochastic 12 bpm model) aerosol was compared to conventional cigarette smoke particle deposition in human lungs. When a continuous particle deposition path (g/cc) was traced through 28 generations of a human lung model, the conventional cigarette model had significantly higher deposition of particles. Of cigarette smoke, 13% was deposited in the lungs; whereas 7% was deposited for e-cigarettes; of the total cigarette smoke deposited, 63% was deposited in the pulmonary region, compared to 44% deposited in the same region by e-cigarettes. Conclusions: The distribution of particle deposition varies between e-cigarettes and tobacco cigarettes. It was determined that tobacco cigarettes produce a much larger number of nanoparticles than the e-cigarette. Though the distribution of e-cigarette particle deposition is less than that of tobacco cigarettes, large quantities of particles are deposited into human lungs. In the future, we plan to conduct hygroscopic trials for e-cigarette and tobacco cigarettes through simulated inhalation in a temperature and moisture controlled environment to better imitate the human airways environment. Acknowledgements: Mercer University Seed Grant; Engineering Scholars Program References: (1) Wang, T. W.; Neff, L. J.; Park-Lee, E.; Ren, C.; Cullen, K. A.; King, B. A. E-Cigarette Use Among Middle and High School Students � United States, 2020. Center for Disease Control and Prevention 2020, MMWR Morbidity and Mortality Weekly Report 2020 (69), 1310�1312. http://dx.doi.org/10.15585/mmwr.mm6937e1.
  • Development of a Low Cost High Alititude Research Platform

    Choi, Anthony; Petherbridge, Colin; Mittleider, Jonathan (2021)
    The development of a low-cost high-altitude platform allows for an increase in high altitude research capabilities for K-12 schools and universities. The High-Altitude Research Platform (HARP) allows for experiments to be launched to an approximate altitude of 110,000 ft (20 miles) allowing for near space environment of extreme temperature change and low-pressure. The system is composed of three main components: the payload, the experiment carriage, and the base station. The payload contains a Raspberry Pi 3 B+ which is used as the main flight computer. The Raspberry Pi is connected to a GPS, temperature, and pressure sensor for datalogging and provides the sensor data to the requesting experiments. The system has multiple types of communication datalinks to maintain connection with the payload. These include a 5.8GHz modem and a 900MHz modem for two-way communication. There is also a one-way low bandwidth APRS tracking system which aids in recovering the payload allowing it to be reusable. The APRS tracking system also allows real-time tracking of the HARP on any internet connected device such as a smartphone. The modems connect to a satellite dish and antenna on the base station with active tracking. This enables high data rate communication up to 30 mile range after the balloon has launched. The experiment carriage accommodates up to twelve 100mm by 100mm ABS cubes, which house individual experiments. These cubes are easily secured into the carriage for launch. The experiments can wirelessly communicate with the base station through a Wi-Fi network hosted on the flight computer. This allows control of the experiments in real time during flight. The re-usability and low cost of the components allows universities and K-12 schools to learn by conducting their own research. The small scale of the system allows for flexibility in the experiments that can be launched. With funding from NASA and the reusable nature of this system, we can offer free launch services to students and researchers. This system brings high altitude research into reach for universities and K-12 schools by being low-cost and rapid. It can be launched at any time allowing for frequent experiments to be conducted. By conducting these experiments, students will be inspired to pursue education and research aligned with NASA�s mission.
  • The role of the patch compartment and elF2? in METH-induced habitual behaviors

    Horner, Ashley; Christy, David; Singhal, Sonia (2021)
    The initial basis of the experiment centered on examining how repetitive exposure to methamphetamine impacts behavior in rat animal models. With repetitive exposure to methamphetamine, the animals can form habitual behaviors resulting from stimulus-response learning, meaning an association is formed between a stimulus and an automatic response. To ensure the repetitive methamphetamine use is a habitual behavior, the drug is paired with a negative stimulus, LiCl, to create an aversion. If the use of methamphetamines is unchanged, then the behavior is considered habitual. Further investigation into the striatum began with the consideration that enhanced activity of the patch compartment, which has a high density of mu opioid receptors, likely corresponds with habitual drug abuse and therefore, higher addiction and habit-forming behaviors. Exposing the animal models to methamphetamines, which have high affinity for mu-opioid receptors, was thought to enhance activation of the patch compartment. However, using designer receptors exclusively activated by designer drugs (DREADDS) contained within a virus, the patch compartment neurons were inhibited and addictive tendencies could potentially be controlled. The four experimental groups include vehicle infusion with saline, vehicle infusion with LiCl, virus infusion with saline, and virus infusion with LiCl. Once the experiment with the animal models was completed, the rats were sacrificed in order to use the brain tissue samples for further examination. To further understand the neurological causes of these behaviors, neurochemical changes in the patch compartment of the striatum were examined using immunohistochemical co-localization staining. The neurons of interest in the patch compartment for this experiment include those that contain the mu opioid receptors and the eukaryotic translation initiation factor 2?, elF2?, antibody. From prior research experiments conducted, reduced activity of elF2? is connected to increasing synaptic connections in the brain and allowing animal models to feel greater senses of pleasure. This inherently leads to increased use of repetitive, habitual uses of drugs. It is possible the use of drugs, such as cocaine and methamphetamines, are causing elF2? inhibition. Performing an immunohistochemical co-localization staining will correlate the elF2? expression levels in mu opioid receptor containing neurons will contribute to the understanding of drug use in the patch compartment of the striatum.
  • Potential ß (1-3)-Glucan Unmasking Genes for Drug Targeting in Candida albicans to Promote Detection by Innate Immune Cells

    Hasim, Sahar; Patel, Sonny; Shankar, Arthi (2021)
    Growing resistance, toxicity, and side effects to current antifungal agents have generated a strong need for further therapeutic developments. Candida albicans are the most common causes of human fungal infections, and they include painful, oral, and vaginal mucosal infections and lethal, invasive bloodstream infections. A key factor for recognizing Candida albicans by Dectin-1 receptor in immune cells is the detection of ß (1-3)-glucan found in the inner cell wall. However, the fungus decreases the efficiency of immune detection by covering ß (1-3)-glucan with a layer of mannosylated glycoproteins, referred to as masking. This study aims to find the gene(s) that enhance ß (1-3)-glucan exposure, leading to increased recognition of Candida albicans by macrophages. We screened several cell wall mutants for unmasking by staining each cell with ß (1-3)-glucan antibody and showing the decreased mannan level by staining with concanavalin A. Overall, our data demonstrated primary evidence suggesting that mutants mnn10?/?, mnn9?/?, and orf19.3869?/?, in Candida albicans showed unmasking in the presence of sublethal caspofungin concentration (50 ng/ml), which promotes the detection by innate immune cells. These genes could serve as potential drug targets that can be used to have synergy when combined with caspofungin against Candida albicans.
  • Impact of Post-processing on Biocompatiblity of 3D-Printed Parts made of Formlabs Durable Resin

    Thomas, Joanna; Stanley, Bailey; Hayes, Sydney (2021)
    With the increased availability and the improved resolution of 3D printers, fabricating medical devices with 3D printers could enable physicians to tailor device features and dimensions to fit each patient’s needs. Some polymers used in 3D printing, e.g. polylactic acid, are considered biocompatible by the FDA; for photo-reactive polymers, used in SLA printers, the chemical composition, the UV-cure settings, and the post-processing steps, can impact their biocompatibility. The focus of this study was the effects of the post-processing on biocompatibility. In particular, we evaluated how IPA wash time affected the biocompatibility of Formlabs Durable resin. Samples were washed for 1, 3, or 6 hrs in >95% IPA, UV cured at 40C for 10 min, and sterilized via 30/30 gravity cycle. They were then placed in cell media according to ** for 72 hours at 37C with 5% CO2. After 72 hrs the media was then placed on mouse fibroblasts growing in 96-well plates and 12-well plates. Cell growth and cytotoxicity were tracked via ATP levels and membrane permeability out to 72 hrs in the 96-well plates. Morphological changes were observed via light microscopy in the 12-well plates at 6 - 12 hr intervals. Plastic or self-expanding metal stents (SEMs) are inserted in the extrahepatic bile ducts (EHBD) to alleviate cholestasis. With the increased availability and the improved resolution of 3D printers, fabricating biliary stents with 3D printers could enable physicians to tailor stent features and dimensions to fit each patient’s needs. 3D-printed, polymeric biliary stents. The focus of this study was to generate an accurate simulation to predict stent behavior under physiologica One of the many secondary uses of biliary stents is the functionalizing of the stent to disperse drugs into a patient’s system as a postoperative treatment. However, certain resins have different cytotoxicity levels. Durable resin has the desired mechanical properties required for use in biliary stents and is expected to have low cytotoxicity. For this 96-well plate study, we explored the cytotoxicity of durable resin and its effect on cell viability. We achieved this by performing cytotoxicity and cell viability assays simultaneously. Cell membranes degrade as a result of cell death. For the cytotoxicity assay, we used the CellTox Green Cytotoxicity Assay to examine membrane integrity, and this is achieved by a nontoxic cyanine dye that binds to dead cells’ DNA. Live cells will not produce a fluorescent signal because the dye is not membrane permeable. A fluorescent signal is produced when the dye binds to the DNA, and the fluorescence reading is directly proportional to the number of dead cells with a well. The cell viability assay that we used was the RealTimeGlo MT Cell Viability Assay. Viability was measured by the production of ATP within the cells through use of a cell membrane permeable NanoLuc® enzyme which attaches to the ATP. Once attached, the NanoLuc® Enzyme produces a luminescent signal, and the signal correlates with the number of viable cells within a well. After conducting these assays, we concluded that the durable resin was not cytotoxic, however the cells did not produce the expected amount of ATP. Therefore, the durable resin does have an effect on cell viability, but the nature of this effect cannot be deduced without further testing.
  • The Effect Of Patch Compartment Neuronal Inhibition upon C-Fos Expression In Methamphetamine Addiction

    Christy, David; Horner, Kristen; Muchandi, Bhuvaneshwari (2021)
    By assessing the nature of cFos neuronal expression in stereotypic habits associated with drug use, treatment models for methamphetamine addiction can be developed to address behavioral issues. The study focuses on the function of the striatum, which is involved in processing environmental information from the cortex to signal the appropriate behavior. Specifically, the patch compartment of the striatum is heavily implicated in addictive patterns through its high levels of mu opioid receptors and possesses an imbalance in cFos neuronal expression compared to its matrix counterpart. Addictive patterns develop through stimulus-response associations to create habit formation with inflexible behaviors, which occur automatically without cognitive processing. The study predicts that selective inhibition of the patch compartment will result in diminished habit formation and stereotypic behaviors associated with methamphetamine abuse. First, the iDREADD vector was inserted through the adeno-associated virus vector into the prelimbic cortex (PLC) and tagged with mCherry to observe the reduction in patch compartment neuronal activity. Then the animals underwent self administration with methamphetamine under a continuous and variable reinforcement schedule to promote habit formation. Aversion training took place in conditioned-place preference chambers to evaluate the inflexible nature of habit formation. Lastly, the rats were sacrificed and immunohistochemistry staining was subsequently performed to analyze cFos neuronal expression. The results indicated a decreased rate of stereotypic behavior within iDREADD infused rats when exposed to noxious stimuli, illustrating the decreased rate of habit formation. Through diminished habit formation, animals can adopt more flexible behavioral patterns to diminish the addictive potential of methamphetamine administration, which can be applied to human models in future research. Future experimentation should be conducted to evaluate the efficacy of inhibiting PLC in equalizing the patch-matrix compartment imbalance.
  • Evaluation of the Efficacy of Fabric Face Masks on the Number of Wash During the Outbreak of Coronavirus (COVID-19)

    Hyun, Sinjae; Nguyen, Minh; Donalson, Garrett; Bradley, Nicholas; Templeton, Trevor; Verma, Maansi; Aldridge, Austin; Spalding, Sarah (2021)
    Evaluation of the Efficacy of Fabric Face Masks on the Number of Wash During the Outbreak of Coronavirus (COVID-19) Minh Nguyen, Garrett Donalson, Nicholas Bradley, Trevor Templeton, Maansi Verma, Austin Aldridge, Sarah Spalding, and Dr. Sinjae Hyun School of Engineering, Mercer University, Macon, GA USA Category: Healthcare Materials BACKGROUND: The main objective of this study was to test the efficacy of common face masks worn by on-campus Mercer students after washing: nylon neck-gaiter, white cloth, and black Mercer-made mask. In March 2020, the outbreak of the coronavirus pandemic from Wuhan, China that has been spreading throughout most countries in the world has cost many innocent lives regardless of advanced medical technology. Wearing a mask has been proven to lower the chance of spreading the virus from the patient to be 1.5% (Lawrie). By providing the general population, especially the Mercer community, individuals will be able to make wise decisions to choose which face mask to wear along with social distancing practice to protect themselves during the coronavirus pandemic. METHODS: The efficacy of face masks is described by (1) filtration efficiency - percentage of particles blocked by the face mask and (2) pressure drop - amount of air flow that determines how hard it is to breathe. The face masks were clamped by a circular-shaped filter holder. Air runs through the mask to measure the pressure drop in cmH2O by using a dual-port manometer (Fieldpiece SDMN5). The filtration efficiencies were tested using the laboratory set-up machine consisting of a Constant Output Atomizer (COA, TSI Aerosol Generator 3076), diffusion dryer, 85Kr neutralizer, facemask sample holder, Wide-range Particle Spectrometer (WPS - 1000XP), flowmeter, and vacuum pump. This setup allowed the facemask sample material to work as a �filter� as it provides the barrier to the transport of aerosol particles made up of sodium. Concentrations of sodium particles in the air after passing through the face masks (filtered) and before the face masks (unfiltered) were measured using the WPS, which measures the concentration of particles in the range of total, nano, submicron, micron, and airborne sizes. The efficacy of three types of face masks was evaluated based on the pressure drop and the filtration efficiency (FE = ((filtered-unfiltered)/unfiltered)*100). After each measurement, face masks were washed during the weekends seven times. The filtration efficiency of the face mask after washing was also evaluated. RESULTS: The white cloth mask has the overall highest pressure drop, and the nylon neck-gaiter has the overall lowest pressure drop. The pressure drop for each of the three types of face masks has an increasing trend after each wash. This is explained by the deterioration of the threads on the face masks that become hairy and fill the space gaps after each wash. In the FE evaluation, the white cloth mask has the overall highest FE in all total, nano, submicron, micron, and airborne sizes, whereas the nylon neck-gaiter has the overall lowest FE in all sizes, respectively. Since this study focuses on how face masks perform during the outbreak of coronavirus, the analysis mainly focuses on the FE in total and airborne sizes. The white cloth mask, again, has the highest FE (FETotal and FEAirborne around 30%), then the black Mercer-made face mask (FETotal and FEAirborne around 20%), and the nylon neck-gaiter has the lowest FE (FETotal and FEAirborne around 0%). All of these masks have the filtration efficiency of less than 50%, so the results suggest using a more multi-layered face mask. The durability of all three face masks after seven times of washing does not have an exact positive or negative slope relationship, and this could be affected by how the particles moved during washing. This suggests saving by washing and reusing the face masks for a one-week duration. CONCLUSIONS: The current study results in a good indication of the efficacy and durability of the face mask materials. The findings will become extremely important for society, especially the Mercer community. Faculty, staff, and students are recommended wearing and rewashing appropriate face masks (about 30% filtration efficiency) and practicing social distancing to enhance the prevention of community spreading of the coronavirus. REFERENCE Lawrie, E. (2020, May 19). Coronavirus: Ryanair boss's face mask claim fact-checked. Retrieved from https://www.bbc.com/news/52707461
  • ß (1-3)-Glucan Unmasking in C. auris for Recognition by Innate Immune Cells

    Hasim, Sahar; Mohapatra, Parneeta; Mahajan, Sarika (2021)
    Multidrug-resistant Candida auris, a major hospital-acquired pathogen, is a severe health threat and poses a significant challenge to healthcare providers. Although there have been several studies on the anti-fungal resistance of this species, there have been very limited cell wall studies on immune responses to unmasking. C. auris cell walls are made of chitin and ß (1-3)-glucan, masked with a layer of mannosylated glycoproteins. This masking decreases the efficiency of immune detection of the ß (1-3)-glucan by innate immune cells (Dectin-1). Caspofungin belongs to the echinocandin family and has been shown to exhibit anti-fungal tendencies and reduce biofilm formation in Candida species by inhibiting the synthesis of ß (1-3)-glucan. We conducted a comparative unmasking study on nine clinical C. auris strains and one Candida albicans wild type (used as the control strain) with different caspofungin concentrations for the unmasking of ß (1-3)-glucan. Unmasking was detected by staining each cell with ß (1-3)-glucan antibodies and examining them under a fluorescent microscope. Biofilm data was also used to map the effects of caspofungin. Atomic force microscope images were used to relate cell topography to caspofungin results. Overall, our data demonstrated primary evidence suggesting that clinical strains 1099, 1100, and 1101 in Candida auris showed unmasking in the presence of sublethal caspofungin concentrations. Comparing the genotypes and phenotypes of caspofungin-sensitive strains versus resistant strains in this study could reveal new drug targets that can address resistant strains and rapid clearance of the pathogen inside the host.
  • Mechanisms of transport and toxicity of methylmercury in placental syncytiotrophoblasts

    Bridges, Christy; McKallip, Robert; Uchakina, Olga; Marroquin, Andres; Ganapathy, Vidya; Vaghela, Simran (2021)
    Methylmercury (MeHg) is a prevalent environmental toxicant that is present in biological systems as a conjugate of thiol-containing molecules, such as cysteine (Cys). MeHg-Cys is a transportable form of methylmercury that can cross the placenta and cause developmental delays and defects in the fetus. However, the mechanisms by which MeHg crosses the placenta are not well characterized. The purpose of the current project was to characterize the mechanisms by which methylmercury is taken up into placental syncytiotrophoblasts and evaluate the toxicity of MeHg on these cells. BeWo cells, a placental syncytiotrophoblast line, were exposed to MeHg-Cys under various conditions and the transport of MeHg-Cys was characterized. Moreover, the toxicity of MeHg-Cys was assessed using the following biochemical assays: TBARS to measure lipid peroxidation, flow cytometry to measure mitochondrial membrane potential and cell viability, Ellman�s assay to measure thiol content within the cell, and autophagy to measure the amount of autophagosomes present. Our findings from the transport studies also show that there are sodium-independent and sodium-dependent transporters involved in the uptake of methylmercury-cysteine into BeWo cells. Potential transport proteins are System L and System B0,+, which are both sodium- independent mechanisms. Exposure to MeHg-Cys was found to be toxic to placental syncytiotrophoblasts. We found that lipid peroxidation and expression of superoxide dismutase increased, and mitochondrial membrane potential decreased, indicating a decrease in viability. The results of this study provide important insight into the mechanisms of MeHg-Cys transport and toxicity in placental syncytiotrophoblasts.
  • Mercury Exposure in Diabetic Rats

    Joshee, Lucy; Bridges, Christy; Farrell, Elisa; Aljic, Sumeja; Pittman, Elizabeth; Matta, Kayla (2021)
    Diabetes is a significant health problem and comorbidity throughout the world that can lead to renal injury and insufficiency. Exposure to environmental toxicants such as mercury (Hg) may also lead to renal injury and insufficiency. Indeed, exposure to Hg has been shown to exacerbate chronic kidney disease (CKD). However, the impact of Hg exposure on renal function in diabetic patients is unclear. The goal of the present study is to test the hypothesis that exposing diabetic animals to Hg will enhance renal injury. To test this hypothesis, we used diabetic and control Wistar rats. Diabetic rats (n = 10) were fed a high-fat diet for 10 days followed by an injection with streptozotocin (65 mg/kg). Control rats (n = 10) were fed a normal diet for 10 days followed by an injection of buffer. Rats with blood glucose levels above 150 mg/dL were considered diabetic. Five rats from each group were administered Hg (5 mg/kg) intravenously and the remaining five rats were administered saline. Rats were sacrificed 24 h after injection, and we measured biomarkers of renal function. Diabetic rats had decreased renal function, evidenced by increased serum creatinine levels and KIM-1 expression. Additionally, the expression of Klotho, SIRT1, and ATG13 was decreased, suggesting impairment in some cellular homeostatic processes. Histological analyses revealed pathological changes in diabetic rat kidneys. The current study provides data related to the mechanisms of renal injury in diabetic patients and shows that, under the current exposure conditions, exposure to Hg does not enhance renal injury in diabetic patients.
  • Study of Glycine and Alanine Coupled with Carboxylic Acids as Biofilm Inhibitors in Common Bacteria Strains

    Goode, David; Hensel, Linda; Severiano, Sara; Tondreau, Jacob; Kight, Parker (2021)
    ?Biofilm is a substance secreted by bacteria cells that offers protection to the bacteria colony, typically from host immune cells. Scientists have found biofilm to cause complications and infections in medical devices such as pacemakers and catheters. Biofilm production is stimulated when enough bacteria communicate through a process known as quorum sensing. This study aimed to identify possible amide coupled carboxylic acids and amino acids that resemble quorum-sensing signaling molecules as biofilm inhibitors in Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans, Escherichia coli, and Bacillus subtilis. Crystal violet assays were used to test for biofilm inhibition; disk diffusion, congo red, and use-dilution assay; and planktonic assays were conducted to test for traditional antibiotic properties of bactericidal or bacteriostatic activity. Gly-4 and Gly-32 were found to be biofilm inhibitors in S. mutans, with 53% and 47% biofilm inhibition respectively; neither drug showed signs of traditional antibacterial properties. Future experiments are required to corroborate this study�s findings, and to explore the efficacy of other drugs with similar functional groups to develop more sophisticated biofilm inhibitors.
  • Chemogenetic Inhibition of Prelimbic Cortex Reduces Habitual Methamphetamine Self-administration

    Christy, David; Horner, Kristen; Dama, Ashitha; Ramesh, Priya (2021)
    Habitual drug use is the continued use of drugs even if the reward is removed or replaced with aversion. This project hypothesizes that habitual drug use will lead to a decrease in Cannabinoid receptor I (CBI) and an increase in Fatty Acid Amide Hydrolase (FAAH) levels. As Methamphetamine (METH) use increases the endocannabinoid release, this might increase the levels of FAAH and decrease the number of cannabinoid receptors to maintain homeostasis. Special receptors called DREADDS, used to prevent the activation of the patch compartment, are infused into the prelimbic cortex that leads to the patch compartment of the rats. Other rats are given a Vehicle (DMSO) during intracranial infusions. Jugular catheters are then inserted to facilitate self-administration of METH. After the self-administration process, the DREADD and DMSO rats are divided further into groups receiving LiCl (aversive stimulus) or saline solution. Immunohistochemistry examines the neurochemical changes in the perfused brain tissue by labelling CBI receptors and FAAH. Initial immunofluorescent staining of CBI was promising. Currently, co-localized staining of CBI and mu-opioid receptors are being performed to draw conclusions about CBI levels between various groups. Since it is difficult to label enzymes such as FAAH, Oleoyl Trifluoromethyl Ketone, an FAAH inhibitor, will be used to determine if FAAH plays a role in long-term depression in the matrix following habitual METH self-administration. Our results also indicate that habitual METH use decreased over time in the DREADD rats during the pre-aversion period. Regardless of whether or not the DMSO rats received LiCl or saline, they preferred to self-administer METH again.

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