## HNSE-O2-4. On the structure of graphs with either convergent or divergent sequences of Pn-line graphs

Alvaro Carbonero1
Faculty Research Mentor: Michelle Robinette, Ph.D.1
1College of Sciences, Department of Mathematical Sciences

ABSTRACT
A graph is a collection of vertices, sometimes called nodes, along with edges, which are lines joining the vertices. By using a procedure called the line graph procedure, we can use a graph G to form a new graph called the line graph of G, or L(G). The procedure forms L(G) by using the edges of G as the vertices of L(G), and by having two vertices in L(G) have an edge joining them if these vertices, as edges, share a vertex in G. The line graph is the simplest graph procedure in a collection of procedures called the H-line graph procedures. In this article, I investigate the properties of the iterated H-line graph procedure, i.e. when the procedure is applied multiple times to the same graph. In particular, I find families of graphs whose iterated H-line graph procedure creates graphs that grow indefinitely in number of vertices. Furthermore, I use these families to find the properties of graphs whose iterated H-line graph procedure produces the same graph after enough iterations.

## HNSE-O2-3. Spike Nozzle Design for Use in Nanosat Orbital Maneuvering

Drew Nemeth1
Faculty Research Mentor: Yi-Tung Chen, Ph.D.sup>1
1Howard R. Hughes College of Engineering, Department of Mechanical Engineering

ABSTRACT
Annular spike nozzle engines have long been the holy grail of rocket engine design, promising superior performance in a smaller package when compared to a conventional bell nozzle. However, flaws inherent to the design of spike nozzles have prevented widespread adoption and testing. As a result, research on potential applications has been quite sparse. This project aims to further spike nozzle research by investigating previously untested materials that literature suggests have potential for use in a spike nozzle design. The goal of the overall research project is to examine component longevity under conditions representative of a small satellite in orbit. An initial literature review concluded that niobium and/or tungsten alloys may outperform previously tested materials (such as carbon and inconel 718) due to their superior thermal performance

## HNSE-O2-2. Graphic Medicine Education for Pediatric Oncology Patients and Caregivers

Natalie Johns1
Faculty Research Mentor: Parvesh Kumar, Ph.D.2
1College of Sciences, Department of Chemistry and Biochemistry
2School of Medicine, Department of Internal Medicine

ABSTRACT
The objective of this work is to create a series of comic vignettes that serve as a clinical educational tool for pediatric patients with a recent cancer diagnosis and their caregivers. These comics are hypothesized to improve patient / caregiver disease understanding in an engaging and aesthetically pleasing way. This tool teaches about cancer, various treatments, side-effects, and good health practices. It is hypothesized to reduce anxiety, improve quality-of-life during therapy, increase treatment compliance, and enhance physician-caregiver engagement.

A recent literature search revealed comics educating caregivers and pediatric cancer patients prior to treatment are currently unavailable. Comics addressing other chronic illnesses, like asthma, were found to be effective forms of health communication (Green & Meyers, 2010; Mickel et. al, 2017; Patel et. al, 2016). The combination of story-telling images paired with simplified text provides an opportunity for experiential learning while allowing readers to become invested in a narrative. Dupuis et al. (2016), Klosky et al. (2017), and Fern et al. (2013), suggest that clear communication with pediatric patients prior to treatment reduces anxiety and improves overall health literacy. Kameny and Bearison found positive outcomes for communicating cancer narratives (2002).

Best practices in patient education and children’s graphic novels were studied prior to creating this work. Common treatment protocols for pediatric cancers were reviewed for accurate representation. Book 1 in Cancer Comics titled “Luke Lionheart Gets Sick” was created and approved by a multidisciplinary team consisting of a pediatric radiation oncologist and specialists in health sciences, children’s literature, and graphic medicine.”

## HNSE-O2-1. Combined Energy Drink and Alcohol Consumption in College Students

Carsyn Hendriks1
Faculty Research Mentor: Arpita Basu, Ph.D.1
1School of Integrated Health Sciences, Department of Kinesiology and Nutrition Sciences

ABSTRACT
The mixing of alcohol and energy drinks is becoming increasingly popular among college students and there is a growing concern for the long-term effect of elevating the risk for developing alcohol use disorder (AUD). There are abundant data on the short-term effects of this elixir such as decreased subjective drunkenness and increased high risk behavior; however, there is little research focused on how this may affect these students as they leave college and further enter adulthood. The purpose of this study is to assess college students’ risk of developing AUD during college due to consumption of alcohol mixed with energy drinks. A survey was sent out to college students primarily at UNLV but available to anyone attending college between the ages of 18 and 24 years old. This survey included questions involving one’s habits of consumption of alcohol, energy drink, and a combination. Questions were selected from two validated alcohol dependency tests: Alcohol Use Disorder Identification Test (AUDIT) and the Severity of Alcohol Dependency Questionnaire (SADQ) and questions regarding energy drink and mixed drink consumption. Results showed a significant increase of risk in the development of AUD for college students who consume alcohol mixed with energy drinks compared to those who consume only alcohol. The results also found a significant increase in the risk of development of AUD in males who consume alcohol with energy drinks versus female equivalents. This study showed no significant correlation in the risk of developing AUD as a student progresses through years in school.

## HNSE-O1-4. Joint Test Machines: An Overview

Drew Nemeth1
Maria Ramos Gonzalez1
Faculty Research Mentor: Brendan O’Toole, Ph.D.1
1Howard R, Hughes College of Engineering, Department of Mechanical Engineering

ABSTRACT
Total knee replacements have been an important tool in the medical field since their introduction in the late 1960s. Invention of the implant and the accompanying procedures has been able to ease human suffering and recover joint functionality for many patients. While great engineering and medical advancements have been made since the first knee replacement design, the current state-of-the-art is not without its flaws. There remain concerns in the medical industry regarding implant operational lifespans, as well as the health effects of residual wear particles which can travel inside the body. Due to this, there are procedures and standards in place which guide knee implant research and testing outside of human trials. Knee implant designs under research are usually tested in machines specifically designed to meet these standards. Such machines often belong to large research labs or are operated by commercial implant testing services. An active research project at the University of Nevada, Las Vegas aims to test a novel implant design. This presentation synthesizes a review of available literature regarding testing procedures, machines, and services. The outcome of this review indicated that current procedures and machines may not be an appropriate match for the active research project. The novel implant design in conjunction with the project’s budgetary restrictions provide ample justification for the design and assembly of a custom built knee implant test machine.

## HNSE-O1-3. A comparative study of machine learning (ML) techniques for imbalanced pediatric patient traumatic brain injury (TBI) mortality prediction

Franklin Fuchs1
Omar Kamal1
Hanao Li1
So Young Ryu, Ph.D.1
Faculty Research Mentor: Mihye Ahn, Ph.D.1

ABSTRACT
Existing Traumatic Brain Injury (TBI) mortality prediction models have not historically accounted for the low mortality rate of pediatric patients, causing class-imbalance problems and undermining classifier prediction performance. We minimize class-imbalance effects by separately implementing case-weighting and subsampling for eight supervised machine learning (ML) techniques, trained and evaluated on pediatric patient National Trauma Data Bank (NTDB) data. The training set consists of pediatric TBI patient records between 2010 and 2014, where records from 2015 are used as the test set. We removed near-zero variance predictors, imputed missing values using a random forest-based algorithm, and implemented double 5-fold cross-validation to independently tune model parameters and filter predictors. Unweighted models, trained on data modified by Synthetic Minority Over-sampling Technique (SMOTE) and Random Over-sampling Examples (ROSE), included Stacked Autoencoder Deep Neural Network (SAE-DNN), K-Nearest Neighbors (KNN), Naive Bayes Classifier (NB), and Support Vector Machine (SVM). Case-weighted models, trained on standardized data, included Artificial Neural Network (ANN), Extreme Gradient Boosting (XGB), C5.0 Decision Tree (C5.0), and Logistic Regression (LR). Preliminarily, XGB and C5.0 trained on standardized data yielded the highest Area Under the Receiver Operating Characteristic (ROC) Curve (AUC) values of 0.9975 and 0.9957 respectively, thus being the models best able to distinguish between classes. Furthermore, C5.0 was the only model to yield a high AUC value while simultaneously exceeding the test set no-information rate of 0.9746 with an Accuracy (ACC) of 0.9915. Additionally, models trained on SMOTE data maximized metrics accounting for class-imbalance and models trained on ROSE data tended to generally underperform.

## HNSE-O1-2. Developmental Neurogenetics-Analysis of Multiple Mouse Strains Resulting in Neurodevelopmental Disorders

Alvaro Carbonero1, 2
Van Vo1
Faculty Research Mentor: Edwin Oh, Ph.D.3
1College of Sciences, Department of Life Sciences
2College of Liberal Arts, Department of Psychology

ABSTRACT
Neurodevelopmental disorders (NDDs) are a group of disorders classified by the abnormal development of the central nervous system (CNS). These disorders, though individually rare, are cumulatively common across the world. The field of neurogenetics has played a significant role in the understanding of these disorders due to the prevalence of certain reported copy number variants (CNVs) and single-gene mutations. In this study, we will utilize multiple Cre-mediated knockout mouse models to 1) model rare neurodevelopmental orders in a mammalian model, and 2) analyze the molecular systems affecting brain development via genetic manipulations and immunohistochemistry. From the deeper analysis of these mutant strains, we are able to characterize multiple genes that play a pivotal role in brain development. More specifically, we are able to show many different cellular mechanisms that are important in the development of NDDs. With a better understanding of these cellular mechanisms, the potential of therapeutics such as novel drug discovery and the development of gene therapies can emerge.

## HNSE-O1-1. Biomaterial Research for a Novel Knee Implant

Ammar Ahmed1, 2
Maria Ramos Gonzalez1
Faculty Research Mentor: Brendan O’Toole, Ph.D.2
1Howard R. Hughes College of Engineering, Department of Mechanical Engineering
2College of Sciences, School of Life Sciences

ABSTRACT
The knee joint is the most complex joint in the human body. It consists of many different bones and ligaments, and can move in six different directions. One component of the knee joint is articular cartilage, which lines the ends of the bones in the joint, and has the function of cushioning the ends of bones, allowing for smooth movement. Osteoarthritis is a degenerative disease that degrades this cartilage, causing inflammation, pain, and reduced mobility in the knee joint. This research evaluated a new biocompatible material, or biomaterial, that will be used to create a novel knee implant that will act as a cushion for the bones of the knee joint to help protect the cartilage from degrading further. This research examined ChronoFlex AR, a Food and Drug Administration (FDA) approved biomaterial, as a possible choice for the proposed knee implant. The study focused on biomedical applications where ChronoFlex AR has been used, comparing it to other biomaterials that have been used in similar applications, and studying its material properties. ChronoFlex AR has been used for non weight bearing implants in the human body, such as artificial heart valves. Similar biomaterials, such as Bionate 80A, have been used in weight bearing implants, such as bone grafts in the spine and hip prostheses. The elastic and anti-stress cracking material properties for ChronoFlex AR were favorable for longevity. The study concluded ChronoFlex AR is a viable material for the proposed knee implant design.

## AHS-O2-4. Soundness and Completeness for Modal Logic

Yuria Mann1, 2
Faculty Research Mentor: Jesse Fitts, Ph.D.3
1Howard R. Hughes College of Engineering, Department of Computer Science
2College of Sciences, Department of Mathematics
3College of Liberal Arts, Department of Philosophy

ABSTRACT
Logical systems have aspects involving meaning and aspects involving form. Two key properties of a logical system are those of soundness and completeness, which are theorems that state, respectively, that provability entails validity and vice versa. A modal is an expression that is used to qualify the truth of a judgment. Modal logic is a particular logical system that studies necessity and possibility. Modal logic deals with possible-world semantics in which something can have true/false values in different worlds and introduces two new operators in addition to the traditional sentential operators. This paper proves soundness and completeness theorems for a novel modal logic proof system developed by Fitts and Beiskecker.

## AHS-O2-3. Effects of helmet use on concussion rates across sport categories

Luke Maietta1
Julia Maietta2
Faculty Mentor: Daniel Allen, PhD.2
1College of Sciences, School of Life Sciences
2College of Liberal Arts, Department of Psychology

ABSTRACT
Objective: Previous research demonstrates that helmet use is effective for preventing severe head injuries. Evidence supporting helmet effectiveness for decreasing concussions is mixed. While prior research has investigated concussion rates in specific sports (e.g., football, rugby), less information is available regarding helmet use across sport categories (i.e., collision, contact, limited-contact). This study investigates whether helmet use impacts the relationship between sport type and concussion rates.

Participants and Methods: Participants included 38,059 high school athletes (mean age=15.1; mean education=9.1; 43.2% female) selected from a larger database who completed ImPACT testing. Exclusionary criteria included: missing data, history of neurodevelopmental disorder, migraines, epilepsy, brain surgery, meningitis, psychiatric, and/or alcohol/substance treatment history. Sports were categorized into groups: collision, contact, limited-contact and were further divided into helmeted and non-helmeted.

Results: Differences in dichotomized concussion history were examined using chi-square which indicated significant differences for helmeted and non-helmeted categories. Specifically, helmeted contact and collision sports had higher concussion frequency than non-helmeted contact and non-helmeted limited-contact sports. Follow-up one-way ANOVA with helmet use and sport category as between-subjects variables indicated a significant main effect for helmet use. The main effect for sport category and the helmet use by category interaction effect were non-significant.

Conclusions: Helmeted contact and collision sports were twice as likely as non-helmeted sports to report concussion. This is consistent with previous research questioning the effectiveness of helmets in reducing concussion. This study was limited by a small sample in the non-helmeted collision and helmeted limited-contact categories. Future research should examine mechanisms underlying these differences.