Click on this link to download the full high-definition interactive pdf for AJUR Volume 22 Issue 1 (March 2025).  The Crossref link for this issue is  https://doi.org/10.33697/ajur.2025.128

Links to individual manuscripts, abstracts, and keywords are provided below.

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p. 3. Modeling Recurrent Emergency Room Trends in the United States

Amanda Bair

https://doi.org/10.33697/ajur.2025.129

ABSTRACT: Emergency departments around the United States struggle with staff shortages and overcrowding following the COVID-19 pandemic and resulting shutdowns. This study aims to create and examine models representing the probability of patients requiring multiple emergency department visits during treatment to better understand why some patients require recurrent emergency department treatments. The two models considered in this experiment are the Poisson Process and the “Frequent Flyer” Hypotheses. Ultimately, analyzing the data provided by the National Center for Health Statistics revealed that the Poisson Process does not accurately represent the realities of recurrent emergency department visits, but the “Frequent Flyer” Hypothesis does in some situations. It also revealed that there may be several lurking variables that compound to determine if a patient will require multiple emergency department visits, accounting for the inconsistencies of the “Frequent Flyer” Hypothesis. KEYWORDS: Recurrent Emergency Room Visits; Repeated and Frequent Emergency Department Visitors; Overcrowding; Emergency Department; Poisson Process; Frequent Flyers; Mathematical Modeling; Healthcare Management; Healthcare Outcomes

p. 15. Caregiver Burden in Parents Providing Care for Children with Serious Mental Illness: A Systematic Review and Meta-Analysis

Pariya Chanthasensack, Rachel E. Dinero, Will P. Randazzo, Toviel J. Francis, & Anna E. Swinchuck

https://doi.org/10.33697/ajur.2025.130

ABSTRACT: Aim: The main purpose of this investigation is to explore and identify the factors that contribute the most to the exacerbation of caregiver burden for informal caregivers of individuals with serious mental illnesses (SMIs). Procedure: Literature searches comprised 18 combinations of search terms related to caregiver burden and serious mental illness. Across eight databases, 1532 articles were identified. After removing 596 duplicates, 936 articles were screened for inclusion criteria, resulting in three studies that met the criteria. This small number of articles included were due to the specificity of our inclusion criteria. From these articles, correlations between caregiver burden and any other variable were extracted. Meta-analysis was conducted using a three-level meta-analytic model. Results: A total of five factors were identified across the included articles: parent age, parent education, parent health, social support, and care recipient characteristics. The three-level meta-analytic model identified the factors parent health, (z = .314, CI [.138, .490], se = .074, t(7) = 4.222, p = .004), and social support (z = -.155 CI [-.282, -.027], se = .056, t(9) = -2.750, p = .022), to have significant overall effect sizes. The remaining factors did not yield significant overall effect sizes. Conclusions: This review reveals that there is still limited research on caregiver burden for caregivers providing support to individuals with SMIs, to the level of specificity that accounts for the different relationships in caregiver-care recipient dyads. However, from the data available, variables that had the largest impact on caregiver burden measures were parental health and social support. These aspects may be possible targets for informal caregiver support. KEYWORDS: Caregiver Burden; Caregiver Burnout; Serious Mental Illness; Informal Caregiver; Parental Caregiver; Risk Factors; Systematic Review; Meta-Analysis

p. 27. The Influence of Gender on the Support and Confidence of Students in Undergraduate STEM Majors

Minnatallah Nassir Elsir Eltinay, Danielle E. Lin Hunter, Porché Spence, & Zakiya Leggett    

https://doi.org/10.33697/ajur.2025.131

ABSTRACT: Gender can have an impact on the intended career pathways in the science, technology, engineering, and mathematics (STEM) fields. This has important implications for research on gender issues in STEM education in larger contexts. In particular, this is essential to gain a better understanding of gender representation, academic confidence, STEM confidence, and career progression in higher education. Using a quantitative questionnaire-based research design approach, this study analyzes the experiences of undergraduate students currently pursuing and enrolled in STEM disciplines at a four-year land-grant university in North Carolina. With family members, friends, peers, classmates, and professors playing a role in supporting undergraduate STEM students, this data signifies a trend of men/self-identified males (males) demonstrating more confidence than women/self-identified females (females). KEYWORDS: STEM Confidence, STEM Identity; Undergraduate Support; Gender Representation; Gender Identification; Higher Education; Scientific Confidence; Underrepresented Students; Undergraduates

p. 37. In silico Analysis of a Nonsense Mutation Linked to Autosomal Recessive Hypercholesterolemia Type 4

Caroline Gardner & Deborah J. Good

https://doi.org/10.33697/ajur.2025.132

ABSTRACT: Autosomal recessive familial hypercholesterolemia-4 (FHCL4) is a genetic disorder caused by mutations in LDLRAP1, a gene encoding a protein that allows the LDL receptor to be endocytosed and degraded in the liver. In silico tools were used to examine the rs121908325 variant linked to FHCL-4. The variant protein LDLRAP1^Q136X affects the coding region of LDLRAP1, resulting in a glutamine amino acid being changed into a stop codon, truncating the protein at amino acid 136. Phylogenetic analysis of ten different animal species demonstrated that glutamine 136 is 100% conserved in the LDLRAP1 protein from the human protein to flies and frogs. An NCBI Conserved Domain Search for LDLRAP1 indicated that the LDLRAP1^Q136X variant truncates the protein within a peptide binding domain, a phosphoinositol binding domain, as well as a domain that specifies the Pleckstrin protein superfamily of signaling proteins. IntFold 3D rendering of wild type (WT) and LDLRAP1^Q136X proteins showed that the variant has a significant alteration in 3D structure, based on the loss of 172 amino acids. Further in silico analysis using amino acid interaction software showed that the LDLRAP1^Q136X protein was missing its phosphotyrosine binding pocket. The rs121908325 mutation is rare, and none of the 70 genomes analyzed during a nutrition course at a large research I university carried this allele. These in silico studies demonstrate that the nonsense mutation at position glutamine 136 would impact specific domains of LDLRAP1, ultimately inhibiting the protein’s ability to perform its function of facilitating removal of the LDL receptor from cell surfaces, leading to increased circulating cholesterol levels and potential cardiovascular health complications.  KEYWORDS: Cholesterol; Hypercholesterolemia; Low density lipoprotein; LDL; LDLR; LDLRAP1; Autosomal recessive hypercholesterolemia-4 (FHCL4); heart disease

p. 47. Investigation of a Photovoltaic Thermal-Direct Expansion Solar-Assisted Heat Pump (PVT-DXSAHP) Collector with Different Photovoltaic Characteristics in Cold Climates

Adam Anastas  & Aggrey Mwesigye

https://doi.org/10.33697/ajur.2025.133

Abstract: In this paper, the performance of a direct expansion solar-assisted heat pump (DX-SAHP) with a photovoltaic thermal (PVT) collector made with different solar cells was investigated. A thermodynamic model of a direct expansion solar-assisted heat pump with a PVT collector and a 180 L water tank for thermal energy storage was developed. The model was implemented in MATLAB, with the CoolProp library for the retrieval of working fluid thermodynamic properties. The solar collector cells considered were ®Solartech, ®LG, ®Prime, ®VOLT, and ®VSUN. The performance of the system is characterized by the coefficient of performance, thermal efficiency, electrical efficiency, heat pump ratio and auxiliary heat ratio. The highest average coefficient of performance of the heat pump was with ®Solartech solar cells on a sunny day in winter was 4.08 , and 7.91 on a sunny summer day. On a cloudy summer day, the ®Prime solar cell had the highest average coefficient of performance at 6.45. The highest electrical efficiency of the collector was observed with ®Prime solar cells, with an efficiency of 14.4%, 16.5% and 13.6%, respectively, from a sunny day in winter, a sunny day in summer and a cloudy day in the summer. The highest thermal efficiency was obtained by ®Solartech solar cells for all weather conditions. With a collector area of 5 m² and a consumer load of 0.001 kg/s, the heat pump meets an average of 15.6% of the total heat needed for domestic hot water demand on a sunny winter day. This increases to 38.2% and 49.0% on cloudy and sunny summer days, respectively. KEYWORDS: Coefficient of Performance; Direct Expansion; Heat Pump Ratio; Photovoltaic Thermal ; Water Heating; Solar-Assisted Heat Pump

p. 65. Ground-dwelling Invertebrate Community Composition Changes between Coastal Sage Scrub Community of San Diego and Tijuana with Urbanization

Anthony Ye & Kyle Haines

https://doi.org/10.33697/ajur.2025.134

ABSTRACT: Invertebrates are some of the most diverse and abundant groups of terrestrial organisms. They provide important functions within an ecosystem and can rapidly respond to environmental changes, such as urbanization, making them excellent ecological indicators for ecosystem function and health. Urbanization, and the disturbance and introduction of exotic plants often associated with it, affects invertebrate taxa, changing community composition, structure, diversity, and abundance of invertebrates. Some invertebrate taxa can exploit these changes and increase in abundance; while others exhibit sensitivity and are at risk of extirpation. The San Diego and Tijuana region has been increasing in urbanizing pressure for decades. Tijuana, in particular, has experienced exponential population growth over the past 30 years, and urbanization threatens the integrity of much of the remaining coastal sage scrub, an endangered and rare ecosystem unique to the coasts of southern California and northwestern Mexico composed of many coastal deciduous shrubs and annual wildflowers. However, the invertebrates currently residing in these semi-disturbed landscapes have rarely been sampled. In this study, ground-dwelling invertebrates from a native plant nursery in an urbanizing area of Tijuana at Vivero Hormiguitas and a protected site in Border Field State Park in San Diego were sampled to compare the changes in coastal sage scrub ground-dwelling invertebrate community composition in response to urbanization. Beetle abundance and richness decreased in the urbanizing site in Tijuana, while spider abundance and richness increased in Tijuana compared to the protected site in San Diego. Particularly, we noted decreases in Tenebrionidae abundance and failed to detect Silphidae, suggesting slower decomposition rates in the urbanizing Tijuana site. Although spider abundance in general increased, mostly due to increased prevalence of one genus, Xysticus, Gnaphosidae abundance decreased in the Tijuana site. Lastly, non-native invertebrate taxa, especially isopods, showed dramatic increases in abundance at the urbanizing Tijuana site, contributing to overall increases in invertebrate abundance in Tijuana compared to the protected site in San Diego. These results indicate that urbanization has negatively affected ecosystem functions in coastal sage scrub communities and that it has drastically impacted the diversity and health of this rare ecosystem, much of which is already fragmented, and actions need to be taken to protect this rare habitat as much of its range continues to become more urbanized. KEYWORDS: Beetle; Coastal Sage Scrub; Community Composition; Disturbance; Invasive Species; Invertebrates; San Diego; Tijuana; Spider; Urbanization

p. 85. Screen Time, Physical Activity, and Anxiety in Honors College Students during the COVID-19 Pandemic

Jack Parker, Karen C. Westervelt, Jeremy Sibold, & Susan Kasser

https://doi.org/10.33697/ajur.2025.135

ABSTRACT: Background: The COVID-19 pandemic presented a unique opportunity to study the effects of increased screen time on student mental health, as colleges and universities in the United States transitioned to virtual learning. Current literature suggests that college/university students, particularly those enrolled in Honors programs, are at an increased risk for symptoms of anxiety. Emerging research suggests that increased screen time increases anxiety but never had there been such a marked increase in screen time. Purpose: The aim of this pilot study was to observe the relationships between anxiety, screen time, and physical activity in Honors students during the COVID-19 pandemic. Methods: A REDCap survey, consisting of the GAD-7 measure of anxiety, screen time questionnaire, physical activity questionnaire, and self-reported impact of the pandemic, was distributed to Honors students. Results: Anxiety and screen time increased during the pandemic, while physical activity did not significantly change. Eighty-point-nine percent of respondents met GAD-7 scoring guidelines for mild to severe anxiety and 71.56% self-reported experiencing more anxiety than before the pandemic. Increased screen time was associated with increased GAD-7 score, independent of physical activity or COVID-19 impact. Increased physical activity was associated with decreased GAD-7 score. Conclusion: Anxiety and screen time increased in Honors students during COVID-19. Increases in screen time were associated with increased anxiety in Honors students, while physical activity was associated with decreased anxiety. Universities should consider strategies to mitigate negative effects of increased screen time, including the use of physical activity. KEYWORDS: COVID-19; Pandemic; Screen Time; Physical Activity; Anxiety; College Students; GAD-7; Technology; Media Effects; Children and Media

Click on this link to download the full high-definition interactive pdf for AJUR Volume 21 Issue 3 (December 2024) or https://doi.org/10.33697/ajur.2024.121

Links to individual manuscripts, abstracts, and keywords are provided below.

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p.3. Externalizing Problems in Children: Examining the Role of Caregiver and Child Adversities and Parental Involvement

Bailey Kersey, Kari N. Thomsen, Debra Bartelli, & Kathryn H. Howell

Department of Psychology, The University of Memphis, Memphis, TN

School of Public Health, The University of Memphis, Memphis, TN

https://doi.org/10.33697/ajur.2024.122

Students: bekersey@memphis.edu, knthmsen@memphis.edu

Mentors: dbrtelli@memphis.edu, k.howell@memphis.edu

ABSTRACT: Previous research has shown that exposure to adverse childhood experiences (ACEs) is associated with increased behavior problems in children. Few studies, however, have taken a multi-informant approach to examine how different factors involving both the child and caregiver affect children’s externalizing problems. Guided by Bowen’s Family Systems Theory, the current study examined how child age and gender, caregiver age, household income, child and caregiver adversity, and child and caregiver report of caregiver involvement were associated with children’s externalizing problems. The sample included 65 caregiver-child dyads recruited from community programs in the Midsouth, United States. Youth were aged 6-12 years and primarily identified as Black or African American (95.45%) and as boys (54.55%). Two linear regression models were run with caregiver-report of child externalizing problems as the dependent variable in both models. One model focused on child variables, including child age, child gender, child adversity, and child-report of parental involvement, while the other centered caregiver variables, including caregiver age, income, caregiver ACEs, and caregiver report of their own parental involvement. Only the caregiver model was significant, with more caregiver ACEs related to higher child externalizing problems. None of the other independent variables were related to child externalizing problems. These results demonstrate the impact of caregiver’s history of adversity on child functioning. Interventions that target children’s externalizing problems may benefit from incorporating an assessment of parent adversity history. Future research should explore underlying mechanisms that may explain this association to identify modifiable factors that could be included in treatments for youth experiencing externalizing problems. KEYWORDS: Intergenerational; Behavior Problems; Adverse Childhood Experiences; ACEs; Caregiver-child Dyads; Youth Functioning; Family Systems; Multi-informant

p.15. Cross-validation Optimal Fold-Number for Model Selection

Angelos Vasilopoulos, Gregory J. Matthews

Stritch School of Medicine, Loyola University Chicago, Chicago, IL

Department of Mathematics and Statistics, Loyola University Chicago, Chicago, IL

https://doi.org/10.33697/ajur.2024.123

Students: avasilopoulos1@luc.edu

Mentor: gmatthews1@luc.edu

ABSTRACT: The resampling method of k-fold cross-validation is popular for error estimation and model selection in computational research. However, there is limited focus in the literature on the question of what fold number k is appropriate for various dataset dimensions. Here we review relevant literature and present a simulation of linear and least absolute shrinkage and selection operator (LASSO) regression prediction error estimation at various values of k and sample size n. In agreement with current literature, we find that contrary to a persisting understanding, there is no bias-variance trade-off in selection of k. Instead, with increasing k both bias and variance decrease, perhaps asymptotically. Our results also suggest a predictable relationship between optimal values of k and n. KEYWORDS: Cross-validation; Optimization; Fold number

p.31. Effects Of Sex Education Perspectives

Tatiana Shojaei, Ryan Glick

Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX

Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX

https://doi.org/10.33697/ajur.2024.124

Students: tmshojaei.99@tamu.edu, ryanglick@tamu.edu

Mentors: saradowd@tamu.edu, rsmallman@tamu.edu

ABSTRACT: Sex education is crucial for promoting informed and healthy sexual behaviors, though the content and approach of these programs have varied significantly. This study examined three distinct approaches to sex education—love and intimacy-based, biology-based, and abstinence-based—with the aim of evaluating how each influenced perceptions of sex, virginity, love, intimacy, and sexual well-being. By examining the strengths and limitations of these strategies, this research aims to enhance the investigation of diverse sex education perspectives. Participants were randomly assigned to one of four groups: love and intimacy-based, biology-based, abstinence-based, or control, with each group receiving a corresponding educational video, except for the control group. Although no statistically significant differences were observed among the groups, participants who already held abstinence-based perspectives were more likely to view virginity as a gift. Significant gender differences were also found, with women reporting higher levels of stigma and stronger associations of love with sex. These findings underscored the impact of participants’ preexisting sex education perspectives and gender on their attitudes toward sex and virginity, suggesting that sex education programs may benefit from accounting for these individual differences to enhance their effectiveness. KEYWORDS: Sex Education; Comprehensive Sex Education; Abstinence-Based Sex Education; Love And Intimacy-Based Sex Education; Biology-Based Sex Education; Sexual Well-Being; Perceptions Of Virginity; Gender Differences; Sexual Attitudes

p.45. Identifying SES Factors in the National Household Education Surveys

Amanda Delore, Ashley Jeanty, & Ron Brown

Graduate School of Arts and Sciences, Lesley University, Cambridge, MA
School of Liberal Arts, Dean College, Franklin, MA

https://doi.org/10.33697/ajur.2024.125

Students: adelore333@gmail.com; ashleyjeanty01@gmail.comMentor: rbrown@dean.edu

ABSTRACT: The purpose of this study was to determine if conceptually and psychometrically rigorous measures of socioeconomic status could be developed for the National Household Educational Surveys (NHES). Exploratory factor analyses were performed for the following NHES: (1) Parent and Family Involvement in Education; (2) School Readiness; (3) Early Childhood Program Participation; (4) After School Programs and Activities; and (5) Adult Education/Adult Education and Lifelong Learning over several years of this administration, including two of the NHES surveys conducted in 2019. The results, while preliminary, suggest that rigorous measures of socioeconomic status (SES) can be constructed for most of the surveys based on Hauser and Warren’s model which used income, education, and occupation. This should enhance inferences based on these data and simultaneously increase the appeal of this database to the educational research community. If the measurement of SES is enhanced, it will fundamentally raise the level of quality of research findings and make them more attractive to educational researchers who use the NHES survey database. KEYWORDS: Educational Attainment; Exploratory Factor Analysis; National Surveys; Parent Involvement; School Readiness; Socioeconomic Status; Data Analysis Methods; Educational Research Databases

p.63. Bavachin Suppresses Cell Growth and Enhances Temozolomide Efficacy in U-87 MG Glioblastoma Cells

Liz Ashing, Ashley Nelson, Zefanias Ngove, Aundrea Crain, & Cole Davidson

Department of Biology, Wartburg College, Waverly, IA

https://doi.org/10.33697/ajur.2024.126

Students: liz.ashing@wartburg.edu, ashley.nelson@wartburg.edu, zef.ngove@wartburg.edu, aundrea.crain@wartburg.edu

Mentor: cole.davidson@wartburg.edu

ABSTRACT: Glioblastoma multiform (GBM) is a lethal cancer affecting the central nervous system. Existing treatment methods for GBM include chemotherapy, radiation, and surgery. Temozolomide is a common chemotherapy treatment for GBM but causes unwanted side effects, as do most chemotherapy treatments. To decrease the harmful side effects of chemotherapy, research has turned to exploring natural compounds to treat cancer. In this study, the natural compound bavachin was investigated to determine cytotoxicity in GBM cells. Bavachin has been tested in many cell lines but not glioblastoma. A sulforhodamine B (SRB) assay, trypan blue counting, and a tumorsphere assay were used to test the hypothesis in this study. It was found that bavachin suppressed glioblastoma cell and tumorsphere viability, had a synergistic interaction with temozolomide, and ornithine decarboxylase was identified as a potential target in silico. This study demonstrated the ability of bavachin to suppress the growth of U-87 MG glioblastoma cells and enhance temozolomide efficacy. These findings demonstrated that bavachin is a potential treatment for GBM based on its ability to suppress cell growth. KEYWORDS: Glioblastoma Multiforme; Temozolomide; Bavachin; Flavonoid; Tumorspheres; Cell Viability; Cancer; Apoptosis; Psoralea corylifolia

p.73. On the Center of Mass of the Half n-Ball

Hugh Riley J. Randall, Carolina C. Ilie

Department of Physics and Astronomy, State University of New York at Oswego, Oswego, NY

https://doi.org/10.33697/ajur.2024.127

Student: hrandal3@oswego.edu

Mentor: carolina.ilie@oswego.edu

ABSTRACT: This project explores how the center of mass (COM) of a half n-ball depends on the dimension, n. We study the case of uniform density, where the COM is equivalent to the object’s centroid, or geometric center. We find a closed form solution, a sequence describing the centroid in n dimensions, which confirms the common two and three dimensional cases. Furthermore, the sequence is analytically proven to converge to zero in the limit as n approaches infinity. KEYWORDS: Mechanics; Mathematical Physics; Center of Mass; Centroid; Hyper-Geometry

Click on this link to download the full high-definition interactive pdf for AJUR Volume 21 Issue 2 (September 2024) or https://doi.org/10.33697/ajur.2024.114

Links to individual manuscripts, abstracts, and keywords are provided below.

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p. 3. Microfiber Content in Pacific Oysters (Crassostrea gigas) from Morro Bay, California
Julia Bures & Andrea Huvard
https://doi.org/10.33697/ajur.2024.115
ABSTRACT: Plastics are a major source of marine pollution. One form of plastic pollution is microfibers, which are synthetic fibers five micrometers or smaller that are shed by artificial clothing. The size of microfibers enables them to easily be ingested by a number of marine organisms, including oysters. Oysters are filter feeders and a major aquaculture asset, which presents a concern for the effects of microfiber ingestion on human health. Very few studies have been conducted quantifying microfibers using Pacific oysters (Crassostrea gigas) sourced from California. This study quantifies microfiber content in the Pacific oyster farmed for human consumption in Morro Bay, California. Microfibers were quantified after being isolated from oyster samples. An average of 9.12 microfibers were recovered per oyster sample. Although some of the smaller oysters contained more microfibers compared to larger oysters, this difference was not significant. There also was no significant difference between the quantities of black and blue microfibers. However, there was a significant increase in quantities of black microfibers compared to green or red microfibers. The results of this study indicate that a large amount of microfibers are present in commercial oysters, but more research needs to be conducted to determine how this will impact human health. KEYWORDS: Marine Pollution; Microplastic; Microfiber; Trophic Transfer; Keystone Species; Aquaculture; Oyster; Human Health

p. 15. Autoregressive Bandits in Near-Unstable or Unstable Environment
Uladzimir Charniauski & Yao Zheng
https://doi.org/10.33697/ajur.2024.116
ABSTRACT: AutoRegressive Bandits (ARBs) is a novel model of a sequential decision-making problem as an autoregressive (AR) process. In this online learning setting, the observed reward follows an autoregressive process, whose action parameters are unknown to the agent and create an AR dynamic that depends on actions the agent chooses. This study empirically demonstrates how assigning the extreme values of systemic stability indexes and other reward-governing parameters severely impairs the ARBs learning in the respective environment. We show that this algorithm suffers numerically larger regrets of higher forms under a weakly stable environment and a strictly exponential regret under the unstable environment over the considered optimization horizon. We also test ARBs against other bandit baselines in both weakly stable and unstable systems to investigate the deteriorating effect of dropping systemic stability on their performance and demonstrate the potential advantage of choosing other competing algorithms in case of weakened stability. Finally, we measure the discussed bandit under various assigned values of key input parameters to study how we can possibly improve this algorithm’s performance under these extreme environmental conditions. KEYWORDS: Reinforcement Learning; Machine Learning; Autoregressive Processes; Bandit Algorithms; Non-Stationary Bandits; Online Learning

p. 27. Extracts from Soil Samples around Pennsylvania Exhibit Potent Antibacterial Properties against Bacillus anthracis
Annalee M. Schmidt, Shawn Xiong, & John N. Alumasa
https://doi.org/10.33697/ajur.2024.117
ABSTRACT: Deadly bacterial infections such as anthrax continue to pose a significant threat to human health worldwide. This disease is caused by Bacillus anthracis, which the CDC classifies as a Tier 1 biological agent due to its ability to form spores resistant to severe environmental stress conditions, including antibiotics. Identifying new antibiotics against this pathogen is therefore crucial for combatting anthrax infections. In this research, crude extracts from Pennsylvania soil were purified using various chromatography methods, resulting in natural products, which were assessed for their antimicrobial properties. After performing minimum inhibitory and bactericidal concentration assays, two compounds, AMS002 and AMS003, exhibited growth inhibitory and killing activity against B. anthracis at 0.8 mg/ml and 0.2 mg/ml, respectively. Both compounds inhibited greater than 80% of protein synthesis relative to the control samples in cell-based and in-vitro fluorescent reporter assays, suggesting that these compounds may target the bacterial protein synthesis pathway as their primary mode of action. The novelty of this discovery is vital due to the resistant nature of B. anthracis spores and their use as a potential weapon in bioterrorism. KEYWORDS: Antibiotics; Resistance; Natural Products; Chromatography; B. anthracis; Minimum Inhibitory Assay; Minimum Bactericidal Assay; Reporter Assays; Course-based Undergraduate Research Experience (CURE)

p. 39. Numerical Solutions for Kinematics of Multi-bar Mechanisms Using Graph Theory and Computer Simulations
Brandon Torresa & Mahdi Farahikia
https://doi.org/10.33697/ajur.2024.118
ABSTRACT: A method is presented to demonstrate the application of computer simulations in the kinematic analysis of planar mechanisms, emphasizing its use in teaching the latter topic in a corresponding undergraduate course. Concepts of rigid-body dynamics are utilized in the kinematics of machines to analyze the motions (and forces in dynamics) transmitted within multiple interconnected links that make a mechanism, such as a car engine, airplane landing gear, press machine, door closer, and so on. Due to the tediousness of the analytical solutions, most textbooks limit the derivation of the equations to four-bar linkages like crank-rocker and crank-slider mechanisms. Benefiting from the advancements in computer programs, such as MATLAB, and their efficiency in solving large systems of linear and nonlinear equations, a method is proposed to facilitate teaching kinematic analysis of multi-bar linkages to undergraduate students while fostering the application of computational engineering via real-life examples. The results obtained from this method are shown to be in excellent agreement with the algebraic solution of the relative motion equations for each element in the mechanism. KEYWORDS: Kinematics of Machines; Linkage; Numerical Solutions; Graph Theory; Machine Dynamics; Computer Simulation; Mechanism; Linkage Kinematics

p. 53. Learning About Food Insecurity in Athens-Clarke County, Georgia Using Key Informant Interviews
Natalie Wong & Michelle Ritchie
https://doi.org/10.33697/ajur.2024.119
ABSTRACT: Several studies have suggested that food insecurity rates increased during the early days of the COVID-19 pandemic. This study sought to assess the strategies employed by food relief organizations to combat this issue amidst the challenges of 2020. Specifically, the research focused on six local food organizations in the Athens, Clarke County area in Georgia. Organizations were contacted via email, and subsequent key informant interviews were conducted via Zoom with the organization’s leaders to understand their responses to food insecurity relief during the 2020 COVID-19 pandemic. The findings were synthesized using a narrative qualitative approach to identify overarching themes in the organizations’ strategies amid the pandemic. Overall, this study revealed a prevalent lack of emergency preparedness among the organizations, exacerbating the issue of food insecurity in the Athens-Clarke County, Georgia area. These results underscore the need for public policy interventions addressing the underlying causes of food insecurity, including the elimination of food deserts, enhancement of food procurement accessibility, improvement of food affordability, and mitigation of associated disparities by race, income, and gender. By understanding the experiences of these organizations amidst the pandemic and the pre-existing factors that contribute to food insecurity, stakeholders, including other organizations, community leaders, and locals may be able to better prepare for future crises. KEYWORDS: Food insecurity; key informant interviews; qualitative analysis; COVID-19; health disparities; food deserts

p. 61. Inadvertent User Outcomes of Wearable Health Technology
Jeremy Cafritz
https://doi.org/10.33697/ajur.2024.120
ABSTRACT: Wearable health technologies are designed to improve a user’s self-awareness of their state of health and increase motivation and physical activity, but there is limited understanding of the psychological and behavioral impact these devices have. The present research attempts to further clarify the influence of individual characteristics on the cognitive, affective, and behavioral outcomes of activity tracker usage, including the development of dependency. A cross-sectional study of 212 college students who used activity trackers was conducted to evaluate the psychological and behavioral impact of activity tracker usage and users’ affective response to their device. Participants expressed more positive affect while wearing their device as opposed to when they were unable to wear it. Female participants exhibited more positive affect than male participants while wearing their device but less when unable to wear it. Only 9% of the sample reported a dependency effect. The dependency effect was negatively associated with intrinsic motivation to be physically active, motivation by the idea of success, and the personality traits of agreeableness and conscientiousness. The dependency effect was positively associated with extrinsic motivation for physical activity and tracker usage, as well as need for cognitive closure. This research elucidates the unintended outcomes of activity tracker usage along with the individual characteristics that present as predictors of these outcomes. KEYWORDS: Health Wearables; Activity Trackers; Physical Activity; Motivation; Dependency; Gamification; Personality

Click on this link to download the full high-definition interactive pdf for AJUR Volume 21 Issue 1 (June 2024) or https://doi.org/10.33697/ajur.2024.108

Links to individual manuscripts, abstracts, and keywords are provided below.

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p.3. Chains of Currency: Manilla Money Bracelets, Early Modern Africa and the Ties That Bind

Sebastian Wang Gaouette & Ellery Frahm

https://doi.org/10.33697/ajur.2024.109

ABSTRACT: Manilla money bracelets emerged during the early modern period (ca. fifteenth century AD) as a form of currency between western Europe and West Africa, and continued to circulate until the early twentieth century. While there has been little formal scholarship on manillas, narratives abound: some histories cast the bracelets as the blood money of the transatlantic slave trade; others highlight them as the copper source used to make the Benin Bronzes; and still others uphold the manilla as a symbolically important West African cultural object in and of itself. This study begins with a history of the manilla, from its rapid proliferation to its eventual obsolescence. The term “metastasizing symbol” is proposed to describe objects like the manilla, whose propagation is underwritten by unsustainable systems of cultural difference, and thereby contains within itself the seeds for the object’s transition to disuse. The authors also describe a portable X-ray fluorescence (pXRF) analysis of nine manilla bracelets from the Yale University Art Gallery (YUAG). When compared to manilla composition data from previous studies and projected into PCA space, the nine YUAG manillas appear most similar to specimens produced in England during the mid-nineteenth century and traded extensively in British West Africa throughout the colonial period. KEYWORDS: Manilla Money Bracelets; pXRF; Transatlantic Slave Trade; Europe; West Africa; Early Modern Period; European Imperialism; Provenance

p.21 Reporting on Antibiotic Resistance in Two US Newspapers Before and During Covid-19

Zachary Weis, Frances Mack, & Amanda Greene

https://doi.org/10.33697/ajur.2024.110

ABSTRACT: Antibiotic resistance (AR) is a growing health crisis that has remained underrepresented in coverage across major news publications in the U.S. despite increasing rates of related disease outbreaks and mortality worldwide. This study used content analysis to examine the coverage of AR in two major U.S. news publications before the COVID-19 pandemic (2018-2019) and during it (2020-2021). Coverage of AR in The New York Times (NYT) and The Washington Post (WP) was analyzed according to the use of frames, the quantity of articles published, and a number of other variables including stakeholders, diseases, and terms referring to AR. These factors were used to assess how coverage of AR differed before and during the COVID-19 pandemic, and how it differed between the two newspapers. Pre-COVID-19 coverage focused on AR as an isolated pandemic, while coverage during the early years of the COVID-19 pandemic often used AR as a supplementary component of the coverage to the main topic of COVID-19. This study found that both before and during the outbreak of COVID-19, the majority of the observed articles did not fully explain the scope, severity, or solution for the AR crisis. Instead, they provided readers with baseline information, framing AR as a contemporary issue and generally encouraging action but included very few tangible suggestions for every day, individual action for readers. KEYWORDS: Superbugs; Frames; Antibiotic Resistance; Coronavirus; COVID-19;  Media Coverage; Health Crises; Medicine

p.33 Challenges of Using Publicly-Available Hospital Data to Quantify Health Effects from Wildfire Plumes in the East San Francisco Bay Area Communities of California, USA

Natasha Atkins & Ronald L. Baskett

https://doi.org/10.33697/ajur.2024.111

ABSTRACT: In the summer and fall of 2018 and 2020, major wildfires in Northern California (USA) impacted the San Francisco Bay Area. The remote 2018 and 2020 wildfires produced the highest PM_2.5 concentrations experienced in the Tri-Valley of the East Bay Area during those two years. The Tri-Valley is composed of the San Ramon, Amador, and Livermore Valleys, surrounded by local terrain that creates a small airshed. In 1967, the California Air Resources Board created 15 Air Basins defined by regional geography, topographic and meteorological conditions. Airshed is sometimes synonymous with an urban-scale component of an Air Basin. We use airshed as a Tri-Valley component of the Bay Area Air Basin. This airshed spans across two counties (Contra Costa and Alameda) and encompasses four cities: San Ramon, Dublin, Pleasanton, and Livermore. PurpleAir (PA) sensors provided good geographic coverage of variation in PM_2.5 in the Tri-Valley airshed. Several studies have established significant health effects from wildfire plumes by associating daily hospital visits with PM_2.5 air quality data at local and regional scales. We hypothesize that during the wildfire smoke periods of 2018 and 2020 in the Tri-Valley area, there was an increase in hospitalizations and ED visits for respiratory (asthma and COPD-related) health effects, as compared to the same time periods during years with less fire activity. The primary goal of this study was to confirm health effects from wildfire plumes on a community scale using 5 years of publicly-available health data. However, with only monthly hospitalization data available, directly linking respiratory hospital and emergency department (ED) visits with PM_2.5 concentrations was unsuccessful. Also, because COVID-19 masked all other causes of hospital visits in 2020, that year was ultimately eliminated from this study. However, visits during November 2018 being much higher than any other November in 2016, 2017, and 2019 implied a potential cause and effect. Daily hospitalization and air quality data are required to quantify any relationship by regression analysis. These findings help inform future studies on the health effects of air quality at community scales. KEYWORDS: PM_2.5 Air Quality; Air Pollutant Exposure; Air Quality Monitoring; Wildfire Smoke; Respiratory Health; PurpleAir Sensors

Supplemental information to “Challenges of Using Publicly-Available Hospital Data to Quantify Health Effects from Wildfire Plumes in the East San Francisco Bay Area Communities of California, USA”

p.47 Disconnected and Online: Privileged Lives of the Transnational Migrants in Mexico City

Isabel Webb Carey

https://doi.org/10.33697/ajur.2024.112

ABSTRACT: As global mobility surges, Mexico City has emerged as a favored destination for remote-working professionals due to its unique fusion of cultural allure and economic convenience. This paper explores the interplay between macroeconomic trends and quests for self-actualization among lifestyle migrants, informed by interviews and other fieldwork conducted in Mexico City in early 2023.  It unravels the complex interplay of factors shaping attitudes, behaviors, and collective identity among these lifestyle migrants and how their conscious embeddedness dissolves as geographic arbitrage imbues them with new privileges. KEYWORDS: Digital Nomads; Lifestyle Migrants; Transnational Migration; Mexico City; Socio-Spatial Exclusion; Gentrification; Privilege; Embeddedness

p.61 Undergraduate Students’ Confidence in Scientific Activity and Support Systems Based on Diversity in an Environmental Science Course

Kimberly J. Parris, Zakiya H. Leggett, & Porche L. Spence

https://doi.org/10.33697/ajur.2024.113

ABSTRACT: Undergraduate student support systems and individual confidence in science courses have been linked to better academic performance among college students. As the topics of diversity and inclusion continue to draw the attention of the collegiate, the problem of equity surrounding supportive learning environments for all races in higher education comes into focus. This paper adds to the literature by highlighting the importance of adequate support for students in collegiate settings. Disparities in student support and confidence with scientific activities among students of color (SOC) and white students in an undergraduate environmental science course had been evaluated. Students (n = 235) were asked to complete a Qualtrics survey containing questions focused on evaluating support from parents, siblings, close relatives, friends, peers, classmates, and professors and confidence regarding self-efficacy in learning and doing scientific activities. The perceived support and confidence in scientific activities in white students and SOC were measured using an independent T-test. The findings demonstrated that white students may have had access to stronger support systems and had higher perceived confidence levels in completing scientific activities based on survey responses. On average, white students had greater perceived support and more confidence. As a result, higher dropout rates, lower performance overall, and alienation of these students in higher education environments could occur. If this trend continues, racial discrepancies suggest that students of color need stronger support networks related to scientific activities in higher education settings. KEYWORDS: Student Support; Student Scientific Confidence; STEM Confidence; Students of Color; Academic Support; Undergraduate Student; Family Support; Student Peers

Click on this link to download the full high-definition interactive pdf for AJUR Volume 20 Issue 4 (March 2024) or https://doi.org/10.33697/ajur.2024.100

Links to individual manuscripts, abstracts, and keywords are provided below.

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p.3. On Sample Size Needed for Block Bootstrap Confidence Intervals to Have Desired Coverage Rates

Mathew Chandy, Elizabeth D. Schifano, & Jun Yan

https://doi.org/10.33697/ajur.2024.101

ABSTRACT: Block bootstrap is widely used in constructing confidence intervals for parameters estimated from stationary time series. Theoretically, the method should provide valid confidence intervals as the length of the time series goes to infinity. In practice, however, it is necessary to know how large of a finite sample is required for block bootstrap confidence intervals to work well. This study aims to answer this question in a simple simulation setting where the data are generated from a first-order autoregressive process. The empirical coverage rates of several commonly used bootstrap confidence intervals for the mean, standard deviation, and the lag-1 autocorrelation coefficient are compared. A quite large sample is found necessary for the intervals to have the right coverage rates even when estimating a simple parameter like the mean. Some block bootstrap methods could fail when estimating the lag-1 autocorrelation. It is surprising that the coverage property even deteriorates as the sample size increases with some commonly used block bootstrap confidence intervals including the percentile intervals and bias-corrected intervals. KEYWORDS: Autocorrelation; Bias-Correction; Centering; Dependent Data; Percentile; Resampling; Simulation; Time Series

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p.17. Faculty Opinions of AI Tools: Text Generators and Machine Translators

Mahlet Yitages & Akie Kasai

https://doi.org/10.33697/ajur.2024.102

ABSTRACT: Artificial Intelligence (AI) tools recently became a prominent concern in higher education classrooms. Many teachers have implemented the technology into their assignments, while others are strictly against this technology’s use for assignments. Either way, students have found ways to use it in their academic careers. Though research on the power of AI in the workplace exists, research is lacking in its appropriate use in higher education. Universities need to define AI’s role on campus and establish guidelines on how these tools may or may not be used and how faculty can recognize misuse, specifically related to academic integrity. This study aimed to determine how faculty view AI as a part of undergraduate literature, language, and linguistics programs. From the interview study, common themes emerged, including implementation, academic integrity, the human aspect of linguistics, and the future of AI writing tools. Interviewed faculty also stated that those in higher education must tread carefully through this strong intersection between technology and the arts to use AI responsibly, strategically, and ethically. KEYWORDS: Artificial Intelligence (AI); Artificial General Intelligence (AGI); Linguistics; Higher Education; ChatGPT; Machine Translation; Academic Integrity; Ethics

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p.29. The Predicted Structure of a Thermophilic Malate Synthase

Shaelee Nielsen, Jantzen Orton, & Bruce R. Howard

https://doi.org/10.33697/ajur.2024.103

ABSTRACT: This project aims to solve the structure of the crenarchaeal Sulfolobus acidocaldarius enzyme malate synthase. Other known malate synthase enzymes have been found to require a magnesium ion in the active site to carry out catalytic activities, but a study reported that S. acidocaldarius malate synthase does not require magnesium. This suggests a novel mechanism for this enzyme. Additionally, the mature S. acidocaldarius protein is approximately 100 residues larger than any other structurally characterized malate synthase. It has also been reported to form a dimer, while previously solved structures have only displayed monomeric, trimeric, and hexameric arrangements. We plan to determine the structure experimentally.  However, major advances in the accuracy of protein structure prediction were made recently by AlphaFold, an artificial intelligence system developed by DeepMind, which has revolutionized the field and has largely solved the protein folding problem. A similar AI system, RoseTTAFold, developed by David Baker’s lab at the University of Washington, has been publicly available. Here, we report our analysis of the structure of this protein, predicted using both of these algorithms and of a predicted structural model for the dimeric form of the enzyme using ClusPro. Our results strongly support a conserved catalytic mechanism requiring magnesium, which is common with all previously solved malate synthase isoforms. KEYWORDS: Glyoxylate Cycle; Malate synthase; Protein Prediction; Thermophile; Sulfolobus acidocaldarius; Magnesium; AlphaFold; RoseTTAFold

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p.39. The Impact of Narratives on Healthcare Decision-Making in Online Discourse

Zayd Almaya & Tom Mould

https://doi.org/10.33697/ajur.2024.104

ABSTRACT: This study examines first what type of evidence is most influential in online discussions for patients when making decisions about their health and second how people deploy, interpret, and react to stories in these online discussions to better understand the role and importance of narrative in the medical field. Data was gathered on the platform Reddit using the subreddit r/melanoma for a duration of two weeks. 242 posts were collected and analyzed. Using a combination of grounded theory and coding criteria from sociologist and narrative scholar Francesca Polletta, a code book was developed and applied to all 242 posts to assess narrative impact and engagement. Results demonstrate that evidence based on past experiences and factual information were the most persuasive. Additionally, stories yielded greater discussion, greater empathetic connections, and greater positive responses from online discussants than other forms of evidence. Further, those positive responses indicate that patients seeking medical advice were more likely to express agreement with the advice when it was offered with a story. Given these results, greater attention should be paid to narratives shared in online communities, particularly considering the levels of misinformation and disinformation found online and the evolving relationships between doctors and patients where authority is no longer so easily assumed. KEYWORDS: Narrative; Personal Experience; Fact; Evidence; Persuasion; Medical Decision-Making; Social Media

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p.53. Elongation Factor P is Required for Processes Associated with Acinetobacter Pathogenesis

Dylan Kostrevski & Anne Witzky

https://doi.org/10.33697/ajur.2024.105

ABSTRACT: Antibiotic resistance is one of the world’s fastest-growing and most prevalent problems today. The influx of antibiotics within our environment from inadequate antibiotic stewardship has led to a surge of drug-resistant microorganisms. The CDC has classified Carbapenem-resistant Acinetobacter (CRA) as an urgent threat within this crisis. New drug development is imperative to combat infections caused by drug-resistant pathogens such as CRA. Bacterial translation, the process of protein synthesis by the ribosome, is a common target for new antibiotic development. Elongation factor P (EF-P) is a universally conserved translation factor required for antibiotic resistance in many bacteria. In this study, we assessed the importance of EF-P in processes associated with Acinetobacter pathogenesis. In the absence of EF-P, Acinetobacter baylyi displays decreased biofilm formation, surface-associated motility, and resistance to beta-lactams and carbapenems. This data holds hope for future drug development targeting EF-P in pathogens closely related to A. baylyi. KEYWORDS: Acinetobacter baylyi; Translation; Ribosome; Elongation Factor P; Polyproline; Biofilm; Surface Associated Motility; Antibiotic Resistance

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p.63. Measurement System for Compliance in Tubular Structures

Ave Kludze, Anthony R. D’Amato, & Yadong Wang

https://doi.org/10.33697/ajur.2024.106

ABSTRACT: Tubular structures such as blood vessels, intestines, and the trachea are common in various life forms. This paper describes a measurement system to test the mechanical compliance of tubular structures. The novelty of the system lies in its hardware and software. Here we use vascular graft as an example to demonstrate the utility of the system. A fully synthetic vascular graft would ideally mimic the mechanical and architectural properties of a native blood vessel. Therefore, mechanical testing of the graft material under physiological pressure is crucial to characterizing its potential in vivo performance. The device operates through a low-cost Arduino-based control system that simulates and measures cyclic fluid pressure changes over time and a laser micrometer that measures diameter changes with pressure. This system is low-cost, assuming one already has access to a laser micrometer. In contrast to previous methods, this system offers a simple, low-cost, and customizable option to measure compliance and is equipped with data acquisition/analysis programs. These programs include a MATLAB application that processes and synchronizes Arduino Uno pressure signals and LabChart Pro diameter readings. Lastly, this paper explains the hardware and software of the measurement system. The system is beneficial for testing the pressure-diameter relationship of tubular structures of varying sizes and materials. KEYWORDS: Tubular Structures; Compliance; Data Acquisition System; Physiological Pressure; Diameter Change; Arduino Uno; LabChart Pro; MATLAB

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p.77. Fibroblast Embedded 3D Collagen as a Potential Tool for Epithelial Wound Repair

Claire Behning, Lia Kelly, Emma Smith, Yizhe Ma, & Louis Roberts

https://doi.org/10.33697/ajur.2023.107

ABSTRACT: Collagen is a functional biomaterial with many applications, including wound healing. 3D collagen hydrogels mimic an in vivo cell culture experience used in cell survival and growth studies. In experimentally examining human cells under contact with 3D collagen, it is possible to understand the role of collagen in human epithelial tissue repair. This study explored the growth and attachment response of human MCF-7 cells when exposed to 3D collagen by investigating if the presence of NIH/3T3 fibroblasts embedded within the collagen should produce an increased wound-healing response. 3D collagen and fibroblast presence were able to be analyzed in tandem with a “sandwich-like” configuration of the gels to determine how these variables impact or improve the tissue repair response in MCF-7 cells. Examinations in growth, attachment, viability, and migration patterns demonstrated that MCF-7 repair response may be increased when in contact with NIH/3T3 embedded 3D collagen without impairing viability. Most notably, results from the migration assay revealed that MCF-7 cells migrate the most when covered by and adhered to cellular 3D collagen. Fibroblast-embedded collagen on top of and below MCF-7 cells exceeded quantitative assessment to near confluency, whereas less than 50 counted cells per image migrated without any top collagen layering. The continuation of these methods could involve in vivo experiments that incorporate live animal models to determine if these results will continue to extend to live tissue. KEYWORDS: Collagen; 3D Collagen; Fibroblasts; Wound Healing; Hydrogels; Tissue Repair; Migration

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Click on this link to download the full high-definition interactive pdf for AJUR Volume 20 Issue 3 (December 2023) or https://doi.org/10.33697/ajur.2023.091

Links to individual manuscripts, abstracts, and keywords are provided below.

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p.3. Walking After Dark: A Sidewalk Illumination Case Study in Cedar City, UT

Sabrina Waite, Ian Nelson, & Jamie Spinney

https://doi.org/10.33697/ajur.2023.092

ABSTRACT: Sidewalks are an important part of public space, but they are becoming increasingly dangerous, especially at night. Therefore, it is important that sidewalks are adequately illuminated to meet the safety, comfort, and accessibility needs (i.e., provide high levels of pedestrian reassurance) to sidewalk users. The objective of this case study was to quantitatively measure and subsequently explore the spatial and statistical distributions of light intensities along the sidewalks that surround Southern Utah University in Cedar City, Utah. A secondary objective was to develop a set of “adequate lighting” guidelines (i.e., 5 to 10 lux) to help identify areas that could benefit from sidewalks lighting enhancements. A digital light meter was used to measure horizontal light intensity, in lux, at a systematic sample of 208 points along the sidewalks within the study area. Geographic coordinates were also collected for each sample observation to enable mapping and spatial analysis of the light intensity data. Results indicate 61% of the observations have lux values equal to zero (complete darkness), 13.4% met or exceeded the minimum guidelines, while 4.3% fell within the “adequate lighting” guidelines adopted by this case study. These results suggest that sidewalks are too dark in too many places to provide reassurance to sidewalk users in the study area. The mapping and spatial analysis results from this case study also provide information to support targeted visibility enhancements of sidewalks within the study area. KEY WORDS: Lighting; Optimum Illuminance; Luminometer; Sidewalks; Pedestrians; Safety; Security; Reassurance

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p.13. Effect of Retinoic Acid on HaCaT and NIH-3T3 cells in an in vitro 3D Collagen Cell Culture Skin Model

Olivia Atkins, Samantha Lopez, Yizhe Ma,& Louis Roberts

https://doi.org/10.33697/ajur.023.093

ABSTRACT: Human skin aging is characterized by epidermal and dermal thinning, loss of elasticity, and wrinkles. Keratinocytes, the most common type of skin cell and fibroblasts, present in the cellular stroma beneath the skin’s surface, each play a role in aging. Using these cell types in in vitro research can reveal a deeper understanding of the dermatological function and cellular changes in aged skin. 3D cell culture techniques provide an opportunity to use these cell types in a model that can more accurately mimic human skin. Treatment of aging skin is of interest to both medical and consumer communities. Retinoic acid (RA) is a metabolite of vitamin A and retinol that assists in cell proliferation, differentiation, and immune functions. Over the counter (OTC) and prescription retinoids are common topical products used for anti-aging and acne treatments. This study seeks to determine the impact of topical retinoid creams on keratinocyte proliferation and morphology in 3D cell culture models of aged and unaged human skin. NIH-3T3 fibroblasts were embedded in a 3D collagen matrix of varying thickness, and HaCaT keratinocytes were seeded on top of the matrix at varying seeding densities to mimic aging and youthful skin. 0.1 µM 0.025% tretinoin and 0.1 µM 0.1% adapalene topical creams were prepared in culture medium and used to treat cells daily, on alternate days, or just once during a week-long period. AlamarBlue assays and microscopy showed that tretinoin treatment was cytotoxic at this concentration, with a single treatment reducing cell viability by ~43% compared to the untreated control. Adapalene treatment, while showing significantly greater cell proliferation than tretinoin, did not exceed the proliferation of the untreated control. It is understood that retinol increases cell turnover by killing cells rapidly, so it is proposed that in our model, the rate of proliferation does not overcome the rate of cell death. Cell viability trends remain similar between young and old skin model treatments. Future studies should focus on creating a 3D model more accurately representing the aging in vivo skin environment where keratinocytes can be readily differentiated from epidermal stem cells. KEYWORDS: HaCaTs; NIH-3T3; Retinoids; Retinoic Acid; Tretinoin; Adapalene; 3D Collagen Gel; Proliferation

ajur.2023.093_appendix

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p.25. Increasing Access to a Four–Year College: Impacts of a California State University Guaranteed Admission Program on College Enrollment Rates

Joleen Chiu

https://doi.org/10.33697/ajur.2023.094

ABSTRACT: Guaranteed admission programs are a type of college access program that provide students who meet certain criteria (e.g., a minimum GPA) with guaranteed admission to one or more colleges. This paper studies guaranteed admission agreements between California State University San Marcos (CSUSM) and its local school district to evaluate if smaller scale, local guaranteed admission programs have comparable impacts on college enrollment rates to previously studied state-wide programs. Employing a regression discontinuity (RD) design around the program’s GPA cutoff conditional on students satisfying other program requirements, this paper finds that the program significantly increased enrollment at CSUSM and at any California State University (CSU) and increased (not significantly) the likelihood of students enrolling at four-year institutions compared to two-year alternatives. In addition, the program disproportionally affected students from underrepresented backgrounds (e.g., first-generation, nonwhite, and low-income backgrounds), suggesting that local guaranteed admission programs also have the potential to increase representation at four-year public institutions and encourage underrepresented students to enroll at higher-quality postsecondary institutions. KEYWORDS: Guaranteed Admission; College Enrollment; College Admissions; College Access; Higher Education; California State University; Education Policy; Local Policy

ajur.2023.094_appendixes

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p.51. Conflicting Socio-Cultural Attitudes and Community Factors Resulting in Backstreet Abortion in Cato Manor, KwaZulu-Natal

Chloe M. Sachs

https://doi.org/10.33697/ajur.2023.095

ABSTRACT: Abortion in South Africa is a complex topic, rife with augmenting and limiting political, social, religious, and cultural factors. This study explores multiple age groups within Cato Manor and whether the attitudes towards abortion and factors impacting the choice of where and whether to receive an abortion differ. The study employs a general qualitative approach with inserted narratives highlighting individual perspectives and stories. The sample cohort was identified using purposive sampling of women, obtained via convenience through the gatekeeper in the community. The participants are from two generations, and two expert interviews were conducted to gain various perspectives. The sample population is from the greater Cato Manor community, and the interviews were conducted in a semi-structured format. The main goal of this study is to understand how socio-cultural factors impact abortion attitudes within each generation in Cato Manor and if community attitudes impact women’s decisions on how and where to obtain medical abortions. The findings show that negative attitudes towards abortion persist in Cato Manor due to religious and cultural rationale. Greater acceptance occurs among younger generations following abortion legalization in South Africa, yet prejudice remains. The research reveals a range of factors that may pressure women to obtain illegal abortion options to avoid community shame. KEYWORDS: Abortion; Pregnancy Termination; South Africa; KwaZulu-Natal; Cato Manor; Backstreet Abortions; Abortion Attitudes; Illegal Abortion

ajur.2023.095_appendix

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p.69. Dynamic Structural Equation Models: Promising Yet Concerning

Suryadyuti Baral & Patrick J. Curran

https://doi.org/10.33697/ajur.2023.096

ABSTRACT: Dynamic Structural Equation Model (DSEM) is a powerful statistical modeling approach that has recently gained popularity among researchers studying intensive longitudinal data. Despite its exciting potential, the stability and replicability of DSEM is yet to be closely examined. This study empirically investigates DSEM using recently published data to explore its strengths and potential limitations. The results show that while some of its parameter estimates are stable, others are characterized by substantial variation as a function of seemingly innocuous initial model estimation conditions. Indeed, some parameters fluctuate between significance and non-significance for the same model estimated using the same data. The instability of DSEM estimates poses a serious threat to the internal and external validity of conclusions drawn from its analyses, challenging the reproducibility of findings from applied research. Given the recent focus on the replication crisis in psychology, it is critical to address these issues as the popularity of DSEM in psychological research continues to rise. Several potential solutions are investigated to address this problem and recommendations of best practice are offered to applied researchers who plan to use DSEM in intensive longitudinal data analysis. KEYWORDS: Dynamic Structural Equation Model; Bayesian; Robust Estimation; Intensive Longitudinal Data

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p.81. Finding the Fixing Number of Johnson Graphs J(n, k) for k Є {2; 3}

James Della-Giustina

https://doi.org/10.33697/ajur.2023.097

ABSTRACT: The graph invariant, aptly named the fixing number, is the smallest number of vertices that, when fixed, eliminate all non-trivial automorphisms (or symmetries) of a graph. Although many graphs have established fixing numbers, Johnson graphs, a family of graphs related to the graph isomorphism problem, have only partially classified fixing numbers. By examining specific orbit sizes of the automorphism group of Johnson graphs and classifying the subsequent remaining subgroups of the automorphism group after iteratively fixing vertices, we provide exact minimal sequences of fixed vertices, in turn establishing the fixing number of infinitely many Johnson graphs. KEYWORDS: Graph Automorphism Groups; Symmetry Breaking; Fixing Number; Determining Number; Johnson Graphs; Kneser Graphs; Graph Invariants; Permutation Groups; Minimal Sized Bases.

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p.91. Anxiety as a Predictor of Movement During a Math Task in Elementary School Children

Gabriella Snetkov, Anna E. Youngkin, Megan E. Lui, Analia Marzoratti, &Tanya M. Evans

https://doi.org/10.33697/ajur.2023.098

ABSTRACT: Anxiety can come in various forms; general anxiety is characterized by feelings of excessive anxiety impacting multiple domains of everyday life, whereas anxiety may also manifest within a single domain (i.e., math anxiety). Those that present with anxiety who also have Autism Spectrum Disorder often exhibit ritualized movement as a coping mechanism for their anxiety. However, the relationship between anxiety and movement has not yet been explored within typically developing children. It is also unclear if the form of anxiety impacts the degree to which children move. In this study, we used Motion Energy Analysis to quantify the relationship between both general and math anxiety and movement during a math flashcards task. Multivariate linear regression analysis was used to determine possible relationships between anxiety and movement. General anxiety significantly contributed to models predicting movement during the math flashcards task, while math anxiety did not. Our results suggest that movement could be an indicator of general anxiety in elementary aged children. KEYWORDS: General Anxiety; Math Anxiety; Elementary; Academics; Motion Energy Analysis; Movement; Ritualized Movement; Mathematics

ajur.2023.098_appendix

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p.99. Chitosan-Silver Thin Film-Coated Titanium Coupons using Silane Linkers Inhibit Biofilm and Planktonic Growth

Emily C. Montgomery, Nidhi Gupta, Matthew Atwill, Joel D. Bumgardner, & J. Amber Jennings

https://doi.org/10.33697/ajur.2023.099

ABSTRACT: Titanium is a component of many implants and orthopedic instruments, such as screws and rods; however, this and other materials may serve as a nidus for bacterial biofilm attachment. Chitosan is a biopolymer with advantages as a surface modifier, and silver ions have broad-spectrum antimicrobial properties. For this study, chitosan is bound to silver through a novel, patented process. The purpose of this research is to characterize silane-linked chitosan-silver coatings for titanium, including comparing antimicrobial efficacy. In this study, silane-linked chitosan-silver titanium coupons reduced Staphylococcus aureus (S. aureus) viability by 98% (planktonic) and 99.5% (biofilm) while supporting viability of Saos-2 osteoblast cells at levels of 75% compared with control uncoated titanium. Due to the observation of retaining osteoblast viability while reducing bacterial viability, silane-linked chitosan-silver coatings could be useful for titanium implants to reduce post-operative infection as well as support the healing process.

KEYWORDS: Titanium; Staphylococcus aureus; Silver; Chitosan; Silane; Osteoblast; Antimicrobial; Coating

Click on this link to download the full high-definition interactive pdf for AJUR Volume 20 Issue 1 (June 2023) or https://doi.org/10.33697/ajur.2023.075

Links to individual manuscripts, abstracts, and keywords are provided below.

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p.3. Divestment Movements over Environmental Issues: The Brazilian Amazon Case

Pedro Eymael

https://doi.org/10.33697/ajur.2023.076

ABSTRACT: Devastating forest fires in Brazil’s Amazon rainforest, one of the most important biomes for Earth’s climate balance, have captured the world’s attention in 2019 and 2020. Foreign governments, non-governmental organizations, and institutional investors pressured Brazilian President Jair Bolsonaro to act and control the situation. Within this context, institutional investors threatened to divest from companies potentially linked to the wildfires and to sell government bonds, creating a divestment movement. Against this background, this article shows that Bolsonaro’s responses varied for each of the groups criticizing the handling of the environmental situation. It is argued that the Brazilian government adopted a more conciliatory tone and took more concrete actions when responding to institutional investors’ demands, compared to the responses for foreign governments and non-governmental organizations (NGOs). Based on fifteen in-depth interviews conducted in 2021 with professionals involved in this divestment case, the paper concludes that institutional investors played a key role in Bolsonaro’s winning coalition and electoral aspirations. Moreover, the shortage of financial capital due to the COVID-19 pandemic created further incentives for Bolsonaro to avoid conflicts with institutional investors. KEYWORDS: Divestment; Amazon Rainforest; Wildfires; Investors; Climate Change; Brazil; Politics

p.27. Using Coral Color to Indicate Coral Health in Five Caribbean Species

Gabriella Herrera, Alexandra M. Good, Alexander Hirota, Catherine Razal, Nicole Gaertner, Justin Sefcik, Jesse Gilbert, & Keisha D. Bahr

https://doi.org/10.33697/ajur.2023.077

ABSTRACT: Coral reefs are one of the most biodiverse and productive ecosystems on Earth, and color has been shown to indicate coral health in Australian and Hawaiian reef systems. However, no standardized method exists to quantify coral health for Caribbean corals. Therefore, a health assessment card using coral color was developed for five species of Caribbean corals to monitor coral health non-invasively. To quantify coral health, individual corals of each species were photographed in a controlled environment to develop color profiles. Simultaneously, nondestructive measurements of “health” were quantified by measuring photosynthetic efficiency (Fv/Fm) using pulse amplitude modulation (PAM) fluorometry, which determines how efficiently the symbiotic algae provides energy to the coral host. The results of this work successfully corresponded photosynthetic efficiency to coral color for five dominant species of Caribbean corals to develop a Coral Health Assessment Card for Caribbean reefs. Implementing a standardized assessment of symbiont performance can assist in monitoring changes in coral health, which can consequently be implemented into long-term and widespread monitoring projects to track overall Caribbean reef health.
KEYWORDS: Photosynthetic Efficiency, Symbiodinium spp., Coral Bleaching, Pulse-amplitude Modulated Fluorometry, Health Assessment

p.37. Synthesis and Palladium-Catalyzed Cross-Coupling of an Alkyl-Substituted Alkenylboronic Acid Pinacol Ester with Aryl Bromides

Shoma Mukai & Nathan S. Werner

https://doi.org/10.33697/ajur.2023.078

ABSTRACT: The palladium-catalyzed cross-coupling reaction of alkyl-substituted alkenylboron reagents with aryl halides is a versatile method to introduce a hydrophobic hydrocarbon chain onto organic compounds of interest. The application of the cross-coupling reaction is enabled by synthetic methods for the preparation of alkenylboron reagents. The geometrically pure, alkyl-substituted alkenylboron reagent, (E)-octenylboronic acid pinacol ester, was prepared by 9-BBN-catalyzed hydroboration reaction of 1-octene with pinacolborane in refluxing 1 M THF solution. This reagent was then evaluated in palladium-catalyzed cross-coupling reactions with aryl bromides. The highest yield of the (E)-1-phenyloctene was obtained when SPhos was used as the ligand, K2CO3 was used as the base, and DMF was used as the reaction solvent. Other electron-rich, electron-poor, sterically hindered, and heteroaromatic substrates produced the corresponding (E)-1-phenyloctene derivatives in moderate to good yield.
KEYWORDS: Organic synthesis; Aryl alkene synthesis; Palladium-catalyzed cross-coupling; Suzuki-Miyaura reaction; Stereocontrolled alkene preparation; Hydroboration; 9-Borobicyclo[3.3.1]nonane; Reaction optimization

p.47. Spawning Conditions Affect Clutch Probability and Size in Laboratory-Housed Zebrafish (Danio rerio)

Sydni Anderson, Elizabeth Sipes, Megan Franke, & Dena R. Hammond-Weinberger

https://doi.org/10.33697/ajur.2023.079

ABSTRACT: Zebrafish are common experimental models used in biological studies that are bred and raised in laboratory settings. Published studies, anecdotal evidence, and industry practices are variable and offer conflicting suggestions on maximizing reproductive success, particularly regarding sex ratios and segregating males and females before spawning. This study identified conditions that promote maximum reproductive success (clutch probability and average clutch size) in zebrafish. Clutch probability was higher when females were seven to ten months old and bred in groups with equal sex ratios and an artificial spawning substrate in the winter or spring. Clutch size was significantly larger when females were seven to ten months old, outnumbered by males, and bred with an artificial spawning substrate. Optional spawning substrates (marbles and plants) improved reproductive success, whereas other parameters had no impact. These data support the implementation of simple steps that reliably maximize reproductive success of laboratory zebrafish.
KEYWORDS: Reproduction; Breeding; Seasonality; Behavior; Substrate; Sex Ratios; Captivity; Eggs

p.59. Color Saturation: Upper and Lower Percentage Histogram Manipulation

Kyra Obert , Maria Schudt , & Ian Bentley

https://doi.org/10.33697/ajur.2023.080

ABSTRACT: There are various color correction techniques that can be applied to digital photographs to account for environmental lighting variations. This manuscript contains a proposed method for such color correction. The method involves saturating an image by a specified percentage of its pixels via upper and lower percentage histogram manipulation using the image’s RGB histograms. Variations of this new technique, the white balance (WB) correction method, and a multivariable fit are used to test its performance against common color correction techniques. The findings demonstrate that the upper and lower percentage histogram manipulation method is not only more applicable to photos because it doesn’t require calibration regions to be sampled but it is also more consistent in its correction of photos when there are substantial gray scale features (e.g. a black and white grid or text). Our motivation for testing these techniques is to find the most robust color correction technique that is broadly applicable (not requiring a color checker chart) and is consistent across different lighting.
KEYWORDS: Color Correction; Histogram Manipulation; Saturation; White Balance; Scientific Image Analysis; Color Comparisons; Euclidean Distance; Standard Deviation; Color Difference

p.77. Overexpression of MMACHC Prevents Craniofacial Phenotypes Caused by Knockdown of znf143b

Isaiah Perez, Nayeli G. Reyes-Nava, Briana E. Pinales, & Anita M. Quintana

https://doi.org/10.33697/ajur.2023.081

ABSTRACT: ZNF143 is a sequence-specific DNA binding protein that regulates the expression of protein-coding genes and small RNA molecules. In humans, ZNF143 interacts with HCFC1, a transcriptional cofactor, to regulate the expression of downstream target genes, including MMACHC, which encodes an enzyme involved in cobalamin (cbl) metabolism. Mutations in HCFC1 or ZNF143 cause an inborn error of cobalamin metabolism characterized by abnormal cbl metabolism, intellectual disability, seizures, and mild to moderate craniofacial abnormalities. However, the mechanisms by which ZNF143 mutations cause individual phenotypes are not completely understood. Defects in metabolism and craniofacial development are hypothesized to occur because of decreased expression of MMACHC. But recent results have called into question this mechanism as the cause for craniofacial development. Therefore, in the present study, we implemented a loss of function analysis to begin to uncover the function of ZNF143 in craniofacial development using the developing zebrafish. The knockdown of znf143b, one zebrafish ortholog of ZNF143, caused craniofacial phenotypes of varied severity, which included a shortened and cleaved Meckel’s cartilage, partial loss of ceratobranchial arches, and a distorted ceratohyal. These phenotypes did not result from a defect in the number of total chondrocytes but were associated with a mild to moderate decrease in mmachc expression. Interestingly, expression of human MMACHC via endogenous transgene prevented the onset of craniofacial phenotypes associated with znf143b knockdown. Collectively, our data establishes that knockdown of znf143b causes craniofacial phenotypes that can be alleviated by increased expression of MMACHC.
KEYWORDS: ZNF143; MMACHC; Vertebrate abnormalities; Cobalamin; cblX-like syndrome; Chondrocytes; Neural crest cells; Hyosymplectic

Click on this link to download the full high-definition interactive pdf for AJUR Volume 19 Issue 4 (March 2023) or https://doi.org/10.33697/ajur.2023.069

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Links to individual manuscripts, abstracts, and keywords are provided below.

p.3. Ethics of Artificial Intelligence in Society

Emma Johnson, Eloy Parrilla, & Austin Burg
https://doi.org/10.33697/ajur.2023.070
ABSTRACT: Every day, artificial intelligence (AI) is becoming more prevalent as new technologies are presented to the public with the intent of integrating them into society. However, these systems are not perfect and are known to cause failures that impact a multitude of people. The purpose of this study is to explore how ethical guidelines are followed by AI when it is being designed and implemented in society. Three ethics theories, along with nine ethical principles of AI, and the Agent, Deed, Consequence (ADC) model were investigated to analyze failures involving AI. When a system fails to follow the models listed, a set of refined ethical principles are created. By analyzing the failures, an understanding of how similar incidents may be prevented was gained. Additionally, the importance of ethics being a part of AI programming was demonstrated, followed by recommendations for the future incorporation of ethics into AI. The term “failure” is specifically used throughout the paper because of the nature in which the events involving AI occur. The events are not necessarily “accidents” since the AI was intended to act in certain ways, but the events are also not “malfunctions” because the AI examples were not internally compromised. For these reasons, the much broader term “failure” is used. KEYWORDS: Ethics; Artificial Intelligence; Agent-Deed-Consequence (ADC) Model; Principles of Artificial Intelligence; Virtue Ethics; Deontology; Consequentialism; AI Systems

p.13. The By-Product of Ozone from Electrostatic Air Cleaners

Giovanni Cerrato & Nelson Fumo
https://doi.org/10.33697/ajur.2023.071
ABSTRACT: Indoor Air Quality (IAQ) contributes to the health and comfort of people living and working indoors. Poor IAQ can be linked to indoor and outdoor sources of contaminants. One recent solution for improving IAQ is the use of Electrostatic (ES) Air Cleaning technology. An ES air cleaner can be installed in an heating, ventilation, and air conditioning system where it pre-filters large dust particles and shocks smaller particles into a collection tray. However, ES air cleaners have been known to give off ozone as a by-product, which is, itself, an air contaminant. Ozone is found outdoors as product of sunlight combining nitrogen oxides and volatile organic compounds generated from man-made pollution. Indoor ozone concentration will depend on the introduction of outdoor ozone indoors through natural ventilation, mechanical ventilation, and infiltration through the building’s envelope (in order of importance). Two different ES air cleaners, A and B, were installed in the air conditioning system of research House #2 of the TRANE Residential Heating and Cooling Research Lab at the University of Texas at Tyler. A series of ozone experiments were conducted, which included measuring the baseline ozone levels at the research houses with different levels of insulation, observing the increase in ozone due to the powering on of mechanical ventilation, and observing the increase in ozone due to the powering on of the installed ES air cleaners. The baseline ozone levels observed in research house #2, whose envelope is more tightly insulated, was found to be lower than in research house #1 whose envelope is less tightly insulated. With regards to mechanical ventilation, an increase in ozone levels were seen in addition to an even higher increase in ozone levels when the ES air cleaners were powered on in tandem. In terms of the single contribution of the ES air cleaners in raising indoor ozone levels, the data shows that although the ES air cleaners increased the ozone concentration in the house, the levels are not of concern as they were less than the FDA limit on indoor ozone generation. KEYWORDS: Indoor Air Quality; Ozone; Electrostatic Air Cleaner; Infiltration; Mechanical Ventilation; HVAC; Pollutant; Indoor Contaminant

p.31. Student Perceptions of Instructor-Student Rapport and Motivation In Hybrid Courses During COVID-19

Bianca S. Candelaria & Meredith L. Clements
https://doi.org/10.33697/ajur.2023.072
ABSTRACT: The relationship between instructors and their students is essential for developing a classroom climate where students feel motivated to learn. The current study surveyed 658 undergraduate students to examine the relationship between instructor-student rapport and motivation in online and face-to-face classes during the COVID-19 pandemic. Results indicated (1) students experienced more rapport with their instructors during face-to-face classes compared to their online classes, (2) students perceived their motivation was greater during face-to-face classes than in online classes, and (3) there was a significant positive relationship between instructor-student rapport and student motivation in both online and face-to-face classes. This study’s findings lend further support to research that emphasizes the importance of creating a sense of community in online classes, where students feel connected to their instructors and, consequently, motivated to learn. KEYWORDS: Instructor-Student Rapport; Motivation; Hybrid Courses; COVID-19; Online Learning

p.41. “The Strong, Silent Type”: Analyzing the Portrayal of the Cost of Masculine Gender Performances in The Sopranos

Holly Taylor & Anna Curtis
https://doi.org/10.33697/ajur.2023.073
ABSTRACT: Media portrayals of the “strong, silent type” reinforce the expectation that men should not demonstrate or even acknowledge their emotions. This trope, however, reflects more significant societal norms around masculine practices that can have profoundly negative impacts on individual men as well as those around them. Emotional compression (or modern stoicism) is fundamentally different from emotional repression. Emotional compression practices can allow men to process their feelings privately and then communicate their feelings clearly without the distortion of uncontrolled bursts of emotion. The treatment of mental health and masculinity in Season 5 of The Sopranos “holds up a mirror” to the costs of emotional repression for men as part of masculine gender performances. The show highlights, sometimes quite brutally, the costs of emotional repression to men and the people around them. In doing so, the content of the show implies that therapy could help men learn to face their feelings and alleviate their suffering as well as that of their families, though only if men are willing to face the feelings of vulnerability that come with having emotions. KEYWORDS: Stoicism; Alexithymia; Hegemonic masculinity; Emotional repression; Mental health; Gender performances

p.53. A Review of the Effect of Estrogen on Immune Efficacy in Zebrafish (Danio rerio) with Comparisons to Human and Murine Homologs

Michael S. Chembars & Lindsey C. Stevenson
https://doi.org/10.33697/ajur.2023.074
ABSTRACT: A review was conducted on current research surrounding the effect of estrogen, and the estrogen receptor, on immune development. Estrogen can regulate many processes and genes throughout immune development, from modulating complement activation and regulating genes crucial for hematopoiesis, to elevating toll-like receptor gene expression. Estrogen has also been shown to have a pronounced effect on regulating certain cancers through inducing macrophage infiltration. It has also been demonstrated to play an important role in the regulation of microRNAs that are important for proper immune development. A greater understanding of this hormone’s effect gained through the zebrafish model can lead to the development of better practices to improve both human and ecological health. Contemporary reviews typically examine the effect of estrogen-like compounds (oftentimes referred to as estrogenic endocrine disrupting compounds) on a sequestered part of immune system development. A distinct lack of cohesion exists in combining contemporary and past reports of the effects of estrogen on various aspects of immune system development in zebrafish. This review serves to fill that gap in knowledge, and to provide a gateway for other researchers interested in this topic. KEYWORDS: Zebrafish; Immune development; Zebrafish immunology; Estrogen; Estrogen receptor; Autoimmunity; Altered signaling; Hematopoiesis

Click on this link to download the full high-definition interactive pdf for AJUR Volume 19 Issue 3 (December 2022) or https://doi.org/10.33697/ajur.2022.063

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Links to individual manuscripts, abstracts, and keywords are provided below.

p.3. Comparison of Genotypic and Phenotypic Predictions for Heavy Metal Resistance in Salmonella enterica and Escherichia coli

Jeevan Rivera-Díaz, Haley Phillippi, Nyduta Mbogo, Erin M. Nawrocki, & Edward G. Dudley

https://doi.org/10.33697/ajur.2022.064

ABSTRACT: Salmonella enterica and Escherichia coli are two pathogenic bacteria of worldwide importance that can infect the gastrointestinal tract. Contamination in the food supply chain is an area of concern. Animal feed may be supplemented with essential trace elements, which function as nutritional additives to promote growth & health and optimize production. Bacteria have acquired many metal resistance genes to adapt to the exposure of metals. In this study, our objectives were to evaluate in S. enterica and E. coli, the correlation between the resistance genotype and phenotype to certain heavy metals, and the ability of conjugative plasmids to transfer antimicrobial resistance genes (AMRGs) and heavy metal resistance genes (HMRGs). A total of 10 strains, five S. enterica and five E. coli, were used for this study. Minimal inhibitory concentrations (MICs) were determined for heavy metals: copper, silver, arsenic, and tellurite. The tested isolates showed resistance to copper (5/10; 50%), arsenic (7/10; 70%), and silver (9/10; 90%). Cohen’s Kappa statistics were used to analyze genotype to phenotype agreements. Among the 10 strains sampled, the accordance between geno- and phenotypic heavy metal resistance was fair for copper (kappa = 0.4), none to slight for arsenic (kappa = 0.19) and tellurite (kappa = 0), and no agreement for silver (kappa = -0.19). The transfer of HMRGs was determined in a conjugation experiment performed for all five Salmonella strains as donors using mixed broth cultures. Transconjugants were obtained only from the genotypically tellurite-resistant strain PSU-3260, which yielded a transfer frequency of 10⁻³ transconjugants per donor. In such strain, the tellurite-resistant genes reside on an IncHI2-type plasmid that shares high DNA sequence identity with known HMRG-disseminating Salmonella plasmids. Our results indicated no considerable correlation between the geno- and phenotypic resistance towards heavy metals in the sampled S. enterica and E. coli. The necessity of research in this area is supported by the lack of standardized protocols and MIC clinical breakpoints for heavy metals.

KEYWORDS: Heavy metal; resistance; Salmonella; E. coli; agriculture; genotype; phenotype; MIC

p.17. Preventing the Activation of a Stress Gene Response in Escherichia coli Using Acetate, Butyrate, and Propionate

Kaylee M. Weigel, Kathleen M Ruff-Schmidt, Birgit M. Prüß, & Danielle L J Condry

https://doi.org/10.33697/ajur.2022.065

ABSTRACT: Regulation of microbial symbiosis in the human intestinal tract is imperative to maintain overall human health and prevent dysbiosis-related diseases, such as inflammatory bowel disease and obesity. Short-chain fatty acids (SCFA) in the intestine are produced by bacterial fermentation and aid in inflammation reduction, dietary fiber digestion, and metabolizing nutrients for the colon. SCFA, notably acetate, butyrate, and propionate, are starting to be used in clinical interventions for GI diseases. While acetate has been shown to mitigate a stress response in the proteome of Escherichia coli cells, little is known about the effects of butyrate and propionate on the same cells. This study aims to evaluate the effects that butyrate and propionate have on the activation of stress promoters in E. coli when induced with a known stressor. Three different strains of E. coli containing the pUCD615 plasmid were used, each with a different promoter fused to the structural genes of the lac operon on the plasmid. Each promoter detected a unique stress response: grpE’::lux fusion (heat shock), recA’::lux fusion (SOS response), and katG’::lux fusion (oxidative damage). Activation of these stress promoters by treatment groups resulted in the emission of bioluminescence which was quantified and compared across treatment groups. All three SCFAs at 25 mM added to cultures prior to stressing the bacteria caused significantly lower bioluminescence levels when compared to the stressed culture without prior addition of SCFA. This indicates that these SCFAs may reduce the stress response in E. coli.

KEYWORDS: Short-chain fatty acids; acetate; butyrate; propionate; Escherichia coli; stress response; Vibrio fischeri luxCDABE; grpE; katG; recA

p.27 Quantification of Microfibers from Marine Sediments from Three Locations in Southern California: An Exposed Beach (Ventura County), a Watershed (Los Angeles County), and an Enclosed Harbor (Orange County)

Adrianna Ebrahim & Mia LeClerc

https://doi.org/10.33697/ajur.2022.066

ABSTRACT: Microfibers are small (<5 mm) fibers made of synthetic materials that are ubiquitous in the environment. The purpose of this observational study was to quantify the number of microfibers in marine sediments and determine which locations have the highest risk for this type of pollution. Sediment samples were taken from three locations in Southern California (Sycamore Watershed, Ventura State Beach Jetty, and Newport Beach Harbor) to determine which had the highest number of microfibers. It was hypothesized that microfibers would be found at each sample site and that the most microfibers would be found at Sycamore Watershed due to its proximity to a wastewater discharge point. The microfibers were separated from the sediment through a process of stratification and filtration and analyzed by a one-way ANOVA and Tukey’s test. Per sample, there was an average of 111.5 (土99.3, n=14) microfibers found per sample at Sycamore Watershed, 59 (土17.4, n=18) at Newport Beach Harbor, and 53 (土14.4, n=18) at Ventura State Beach Jetty. A total of 3,590 microfibers were found from all three sample sites. Analysis revealed that Sycamore Watershed had significantly more microfibers than any other site (p<.05). It is likely that Sycamore Watershed had the most microfibers because of its proximity to a sewage-sludge disposal site that contains the polluted water from our washing machines. In conclusion, microfibers are polluting the sediments in harbors, open coastlines, and watersheds in California, negatively affecting the ecosystems in these areas.

KEYWORDS: Microfiber; Microplastic; Macroplastic; Marine Pollution; Synthetic Materials; Wastewater Treatment Plants; Sediments; Watershed; Harbor; Jetty

p. 37. Stabilization of Cisplatin via Coordination of Ethylenediamine

Samantha L. Rea, Alexia Smith, Brooke Hornberger, Grace Fillmore, Jeremy Burkett, & Timothy Dwyer

https://doi.org/10.33697/ajur.2022.067

ABSTRACT: While the chemotherapeutic cisplatin is used to treat a variety of cancers, metal toxicity and cisplatin resistance via genetic and epigenetic changes limits its use and calls for alternative therapies. To combat the observed toxicities and create a more stable compound, which avoids isomerization into a trans configuration, three cisplatin analogues including cispalladium, dichloro-(ethylenediamine)-platinum(II), and dichloro-(ethylenediamine)-palladium(II) were synthesized as potential cisplatin alternatives. Each compound was evaluated for cytotoxicity on SK-OV-3 cells against cisplatin. Synthesis of dichloro-(ethylenediamine)-platinum(II) yielded 20.5% of the theoretical yield, while dichloro-(ethylenediamine)-palladium(II) yielded 49.1%. Results from the cytotoxicity trial revealed that cispalladium was not effective against SK-OV-3 cells, and dichloro-(ethylenediamine)-palladium had minimal effects. The dichloro-(ethylenediamine)-platinum(II) was the most efficacious with an IC₅₀ value of 0.77 µg/ml compared to the IC₅₀ of 0.61 µg/ml for cisplatin. With a similar IC₅₀ to cisplatin, these results suggest that dichloro-(ethylenediamine)-platinum(II) has the potential to serve as a cisplatin alternative for cancer patients who develop resistance following their clinical course of cisplatin. Future studies on the cytotoxicity of dichloro-(ethylenediamine)-platinum(II) to induce cell death on cisplatin-resistance cell lines are necessary to determine the ability of the compound to be utilized as a cisplatin alternative.

KEYWORDS: Cisplatin; Ovarian Cancer; SK-OV-3; Drug Resistance; Stability; Palladium; Ethylenediamine; Cispalladium; Dichloro-(ethylenediamine)-platinum(II); Dichloro-(ethylenediamine)-palladium(II)

p.47. Novel Interactors of the SH2 Domain of the Signaling Adaptors CRK and CRKL Identified in Neuro2A Cells

Caroline M. Dumas, Anna M. Schmoker, Shannon R. Bennett, Amara S. Chittenden, Chelsea B. Darwin, Helena K. Gaffney, Hannah L. Lewis, Eliana Moskovitz, Jonah T. Rehak, Anna A. Renzi, Claire E. Rothfelder, Adam J. Slamin, Megan E. Tammaro, Leigh M. Sweet, & Bryan A. Ballif^*

https://doi.org/10.33697/ajur.2022.068

ABSTRACT: CT10 regulator of kinase (CRK) and CRK-like (CRKL) form a family of signaling adaptor proteins that serve important roles in the regulation of fundamental cellular processes, including cell motility and proliferation, in a variety of cell types. The Src Homology 2 (SH2) domain of CRK and CRKL interacts with proteins containing phosphorylated tyrosine-X-X-proline (pYXXP) motifs, facilitating complex formation during signaling events. A handful of CRK/CRKL-SH2-specific interactors have been identified to date, although in silico analyses suggest that many additional interactors remain to be found. To identify CRK/CRKL-SH2 interactors with potential involvement in neuronal development, we conducted a mass spectrometry-based proteomics screen using a neuronal cell line (Neuro2A, or N2A). This resulted in the identification of 132 (6 known and 126 novel) YXXP-containing CRK/CRKL-SH2 interactors, of which 77 were stimulated to bind to the CRK/CRKL-SH2 domain following tyrosine phosphatase inhibition. Approximately half of the proteins identified were common interactors of both the CRK- and CRKL-SH2 domains. However, both CRK family member SH2 domains exhibited unique binding partners across experimental replicates. These findings reveal an abundance of novel neuronal CRK/CRKL-SH2 domain binding partners and suggest that CRK family SH2 domains possess undescribed docking preferences beyond the canonical pYXXP motif.

KEYWORDS: CRK; CRKL; SH2; LC-MS/MS; Proteomics; Neurodevelopment; Signal Transduction

SUPPLEMENT 1 (Figures)

SUPPLEMENT 2 (Tables)

Click on this link to download the full high-definition interactive pdf for AJUR Volume 19 Issue 2 (September 2022) or https://doi.org/10.33697/ajur.2022.058

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Links to individual manuscripts, abstracts, and keywords are provided below.

p.3. Evaluating Driveway Cross Slopes and Social Equity in Cedar City, UT

Brock Anderson* & Jamie Spinney

Department of Geosciences, Southern Utah University, Cedar City, UT

https://doi.org/10.33697/ajur.2022.059

Student: brock20anderson00@gmail.com*

Mentor: jamie.spinney@suu.edu

ABSTRACT

The Americans with Disabilities Act (ADA) is the most comprehensive law governing accessibility, and it requires local governments to develop transition plans to become compliant. Among the key ADA requirements is a continuous unobstructed pedestrian circulation network that consists of a sidewalk that has a cross slope of no more than two degrees. The primary objective of this research was to evaluate whether driveway cross slopes in Cedar City were ADA compliant, so a digital level was used to measure a random sample of driveway cross slopes. A secondary objective was to determine whether there is evidence of social inequities in Cedar City’s pedestrian environment. The estimated value of each residential property (a proxy for income) was retrieved from Zillow® to evaluate the statistical relationship between incomes and driveway cross slopes. The results of this study indicate that there was no widespread evidence of social inequities. However, most driveway cross slopes (78.8 percent) were not ADA compliant and, thus, require retrofitting that should incorporate more widespread use of sidewalk buffer strips. The results also highlight priority areas for sidewalk improvements and can be used to inform a transition plan for sidewalk enhancements and funding.

KEYWORDS

Social Equity; ADA; Sidewalks; Advocacy Planning; Driveway Cross Slope; Walkability

p.11. Conversations About Mental Health and Well-being During the COVID-19 Pandemic: Why and How Restaurant Employees Talk With Each Other and Managers

Anamaria Tepordei* & Kirsten Foot

Department of Communication, University of Washington, Seattle, WA

https://doi.org/10.33697/ajur.2022.060

Student: anamaria.tepordei@outlook.com*
Mentor: kfoot@uw.edu

ABSTRACT
Restaurant employees in the United States have experienced unprecedented challenges to their mental health and well-being (MHW) during the COVID-19 pandemic, yet little is known about communication regarding MHW in the restaurant industry. Drawing on health, organizational, and interpersonal communication concepts, this exploratory, survey-based study probed whether, how, and why or why not restaurant employees in western Washington State conversed about MHW with one another and their managers during the winter of 2021. Key findings include that there are many reasons why some restaurant employees do not engage in conversations about MHW with other members of the workplace. However, when such conversations do occur, they are typically mutual, positive, and relationally-oriented—more so among coworkers than between employees and managers. Additionally, both coworkers and managers are sources of social support and resource exchange during these conversations, although the evidence is stronger among coworkers. Our findings contribute to the extant literature on mental health communication in the workplace and demonstrate the merit in more closely examining superior-subordinate and coworker communication about personal and sensitive topics, like MHW. Comparative analysis of employees’ MHW-related communication with coworkers versus managers revealed both similarities and differences that carry implications for managerial practice and future research.

KEYWORDS
Mental Health and Well-being (MHW); Disclosure; Superior-subordinate Communication; Peer Coworker; Social Exchange; Social Support; Interpersonal Communication Motives (ICM), Restaurant Employees

p. 33. Differential Expression of Hub Genes and Activation of p53 by Anti-cancer Compound Curaxin CBL0137

Tanvi Patel*, Rochelle Ratner, & Niharika Nath

Department of Biological & Chemical Sciences, New York Institute of Technology, New York, NY

https://doi.org/10.33697/ajur.2022.061

Students: tpatel60@nyit.edu*, rratne02@nyit.edu

Mentor: nnath@nyit.edu

ABSTRACT

Cancer is a global concern and there is a need for effective drugs. CBL0137 is a small water-soluble molecule and a new second-generation compound in the family of curaxins with potential anti-cancer activity. Curaxins in general, including CBL0137 intercalate into DNA, and act by targeting the histone chaperone ‘facilitates chromatin transcription’ (FACT) complex and have the potential to treat tumors by reducing the growth of cancer cells which is shown in a variety of cell lines and animal models. CBL0137 is found to activate the tumor suppressor gene p53. However, the mechanism of p53 activation is poorly understood. Utilizing bioinformatics analysis on available datasets of CBL0137 treated cancer cells of glioma, cervical and multiple myeloma, differentially expressed genes (DEGs) that may lead to the activation of p53 were examined. Three GEO datasets of cells treated with various concentrations of CBL0137 were analyzed, namely HSJD-DIPG007 (GSE153441), MM1.S (GSE117611) and HeLa S3 (GSE117611). The DEGs were identified based on p-values less than 0.05, logFC values greater than 1 and less than -1 and analyzed using GEO2R, Enrichr, and STRING, and data visualization was performed on Tableau. Compared to the controls, a total of 229, 1425, and 1005 genes were upregulated while 368, 2322, and 1673 genes were downregulated for HSJD-DIPG007, MM1.S and HeLa S3 datasets, respectively. Further collective analysis revealed a total of 38 common DEGs among the three datasets. Using Enrichr and STRING on these 38 DEGs, seven hub genes were obtained, SKP2, RGS16, CSRP2, CENPA, HJURP, DTL, and HEXIM1 with these possible mechanisms:  inhibition of AKT phosphorylation by upregulated genes RGS16 and CSRP2, p300-mediated acetylation of p53 via SKP2, inhibition of MDM2 by DTL downregulation and HEXIM1 upregulation, and inhibition of AURKB via CENPA and HJURP downregulation. This study analyzed the three datasets and highlighted how these identified hub genes may play a role in leading to p53 activation by CBL0137.

KEYWORDS

Curaxin; CBL0137; Differentially Expressed Genes; Cancer; p53; Glioblastoma; Cervical; Myeloma

p. 43. Cemetery Analysis of Whitewater, WI

David H. Nehlsen

Department of Political Science and Philosophy at the University of Green Bay, WI

https://doi.org/10.33697/ajur.2022.062

Students: nehldh03@uchicago.edu*

Mentor: weinscha@uwgb.edu

ABSTRACT

Procedures and customs surrounding funerals, burial, and grave marking vary widely by time period, location, culture, and religion, among many other factors. This project investigated the gravestone customs of cemeteries in Southern Wisconsin, USA. Utilizing a dataset of 500 gravestone samples collected from cemeteries in Whitewater, WI, the aim of this project was to objectively measure how people choose to remember their dead and how these practices have evolved over the years. Because of the decline in American religiosity in recent decades, the expectation of this project was to see the usage of religious symbols decline. Based upon this analysis, this does not appear to be the case. Practices such as the recording of one’s name and year of birth/death have remained constant; however, other customs of remembrance, such as the use of religious symbols and the recording of one’s date of marriage, have shifted dramatically over the years, reflecting the evolution of society and culture.

KEYWORDS

Cemetery; Symbols; Funeral; Thanatology; Death; Demography; Monuments; History