The Cupola 2020 - Poster Edition

Page 1

2019–2020 POSTER EDITION Christopher Ne wport un iver si ty Cupola The

The Cupola

2019-2020

Poster Edition

Volume 1

The Undergraduate Research Journal of

Christopher Newport University

1 Avenue of the Arts

Newport News, VA 23606

The Cupola is the undergraduate research journal of Christopher Newport University. Publication of The Cupola is made possible by the generous support of the Douglas K. Gordon Endowed Fund.

Papers published in The Cupola have undergone review by the Undergraduate and Graduate Research Council. The final product has been edited and compiled by the Office of Undergraduate Research and Creative Activity. The Cupola is published in print and online at www.cnu.edu/research.

Each poster published in this special edition of The Cupola is awarded a $100 stipend in recognition of the fine work of the students.

The Cupola (Newport News, Va. Print)

ISSN 2688-5913

Cupola (Newport News, Va. Online)

ISSN 2688-5921

©2020

All rights belong to individual authors

The Office of Undergraduate Research and Creative Activity

Dr. David A. Salomon, Director

Dr. Michaela Meyer, Academic Director

757.594.8586

cnu.edu/research

interweb.cnu.edu/research

Welcome to a special poster edition of The Cupola, Christopher Newport University’s undergraduate research journal. As the Director of Undergraduate Research and Creative Activity, it is my pleasure to serve as the journal’s editor, establishing guidelines and facilitating the vetting process. In this strange and unusual year, given the global pandemic and the overdue worldwide protests against racial injustice, the OURCA determined to print posters, particularly highlighting the work of students which had been accepted for presentation at prestigious conferences and annual meetings cancelled by the pandemic. We are proud to publish fifteen of the best examples of undergraduate research at Christopher Newport University.

The Office of Undergraduate Research and Creativity is proud of these students who, with enthusiastic and skilled faculty mentorship, continue to produce insightful and meaningful work.

The OURCA would like to thank the members of the 2019-2020 Undergraduate Research Committee: Co-chair Dr. Andria Timmer; Co-Chair Prof. Denise Gillman; Dr. John Thompson, Dr. Rocio Gordon, Dr. Robert Winder, Dr. Leslie Rollins, Dr. Olga Lipatova, Dr. Farideh D. Mohammadi, Dr. Hussam Timani, Ms. Mary Sellen, and Dr. Michaela Meyer.

Thanks to Courtney Michel, Creative Services Manager of CNU’s Office of Communications and Public Relations, for her astonishing talent, patience, and artistry in designing the layout of The Cupola.

Special thanks to Provost David Doughty, Vice Provost Geoffrey Klein, and OURCA administrative assistant Michaele Baux.

July 2020

A Note from the Director
Cade Cobbs, Emma S. Dryden, Jessica S. Thompson 1 nd Heather D. Harwell Investigating the impact of storm events on the availability of terrestrial insect prey to mummichog (Fundulus heteroclitus) Kali DeBorde, Caitlyn Sullivan, Erin Mills, Brittany Rininger, 3 and Ayesha Ferozpuri Dwell Time Differs as a Function of Emotion and Social Anxiety Levels Christopher Duncan 5 Autonomic Correlates of Mental Toughness Sarah Goldsmith, Emery Harlan, and Susannah Garber 7 Effects of Stress on Behavioral Inhibition in Male and Female Rats Tested via Operant Touchscreen Chambers Katelyn Hark 9 The Influence of the Dark Tetrad Personality Traits on Cyberbullying Behavior Creid Johnson 11 Processing and Visualization of EEG Data Using EEGLAB Alexis Khuu, Katherine Goida, and Natasha Woods 13 Effect of encoding variability on mnemonic discrimination: An ERP study Katie Kozlowski, Kali DeBorde, Ayesha Ferozpuri, 15 Karen Salazar, and Peyton Stites Does Accurate Facial Expression Recognition Influence Dwell Time? Nafessa Lodi 17 Developmental Improvements on the Forced-Choice Mnemonic Similarity Task in Childhood Mara McFadden 19 The Threshold Hypothesis: A Statistical Analysis Leah O’Neill 21 Maternal Subpopulation Variances In Vaginal And Cesarean Section Delivery Methods Predicts Excess Infant Mortality Of Blacks In United States: Linked Birth/Infant Death Records, 2007-2016 Ryan Saal, Zoe Stauffer, and Shreya Ganta 23 Detection of bacterial contamination by nitroreductase Sara Safford and Connor Beveridge 25 Intramolecular Difunctionalizations of Tethered A minoalkenes with Hypervalent Iodine Caroline Tsui 27 The degradation of polyethylene terephthalate by Ideonella sakaiensis under varied conditions Noah Wallace 29 Investigations of PETase from Ideonella sakaiensis, a plastic-degrading bacterium
Table of Contents

Abstract

Estuarine habitats are impacted by climate change due to rising sea level, increasing temperatures, and more frequent storm events. Global change could have major implications for species in these habitats, including the mummichog (Fundulus hetereoclitus), which is a resident fish species of intertidal salt marshes of the Chesapeake Bay. The objective of this study was to investigate how consumption of terrestrial insect prey by mummichogs was affected by storm events and monthly variation in Hoffler Creek, a tidal creek in Portsmouth, VA. We compared the gut contents of mummichogs collected at two sites along an upstream-downstream gradient during a dry weather period prior to a storm each month from June to August 2019, as well as during a subsequent storm event in June and July. Fish were collected using unbaited minnow traps, humanely euthanized using MS-222, and preserved in 10% buffered formalin. Prey items in the first two sections of the gut were cataloged to account for the most recently consumed items. A Fisher’s one-tailed exact test (α=0.05) indicated that there was a significant increase in the

proportion of terrestrial insect prey consumed during the storm event only at the upstream site in June (p=0.04). A 2x3 Chi-square test (α=0.05) was used to assess the effect of month on consumption of insect versus non-insect prey; we found that there was a significant difference in the proportion of terrestrial insect prey consumed at the upstream site (X2=16.91, p<0.01), the highest of which occurred in August, but not at the downstream site (X2=3.43, p=0.18). Terrestrial insect prey represents an important energy source for mummichogs, and its availability could increase when storms knock insects into the water at sites similar to the upstream site in this study, where the marsh is in close proximity to the upland habitat. Increased storm events may, therefore, result in an unexpected benefit of climate change for mummichogs. Mummichog consumption patterns are also impacted by monthly variation in insect abundance, which will be impacted by climate change in, as yet, unknown ways.

Cade Cobbs is an Organismal Biology major with minors in Chemistry and Spanish. He has been involved in undergraduate research since his freshman year at CNU and was a Summer Scholar in the summer of 2019. He is a member of the Class of 2020 and plans to attend graduate school in the Fall to obtain a Master’s Degree in Marine Biology and will later pursue a PhD to become a professor.

Emma Dryden is an Organismal Biology major with Leadership Studies and Environmental Studies minors. She is also a member of the Class of 2020. She has been involved with undergraduate research since her sophomore year and was a Summer Scholar in the summer of 2019. She plans to apply to veterinary school in the coming cycle to join the Class of 2025.

Investigating the impact of storm events on the availability of terrestrial insect prey to mummichog (Fundulus heteroclitus)
This poster was accepted for presentation at the 34th Annual Meeting of the Tidewater Chapter of the American Fisheries Society.
2

Dwell Time Differs as a Function of Emotion and Social Anxiety Levels

Kali DeBorde, Caitlyn Sullivan, Erin Mills, Brittany Rininger, and Ayesha Ferozpuri

Faculty Sponsor: Dr. Laurie Hunter, Department of Psychology

Abstract

The current study explored the eye-tracking patterns, via the eye-tracking metric of visit duration, of individuals with and without social anxiety symptomatology when processing emotional expressions. In the current study we extend prior research by exploring how various areas (AOIs) of facial expressions of emotion are processed by individuals with and without social anxiety symptomatology. Forty-six undergraduate students from a small liberal arts university in the Mid-Atlantic viewed an 80-slide presentation of faces, taken from CAFE child facial set (LoBue & Thrasher, 2014) and NimStim adult facial set (Tottenham et al., 2009) while measures of eye-tracking were documented using Tobii X3-120. Participants were instructed to label the faces

with the appropriate emotion. Participants were asked to complete the Liebowitz Social Anxiety Scale which was used for grouping purposes. Participants were grouped into two groups based on the clinical cut-off values (low SAS, less than 55; high SAS greater than 55). A 2 (SAS high or low) X 2 (age of face) X 5 (emotion)X 4 (AOI)

ANOVA was conducted to assess visit duration. A 3-way interaction effect was found for visit duration F(4, 176) = 2.736, p = 0.030 (see Figure 1). Although no effects for AOIs were obtained, individuals with high social anxiety spent more time processing child faces expressing anger.

Kali DeBorde is a senior Psychology major with a minor in Childhood Studies at Christopher Newport University. In the fall, she will be pursuing her Master’s in speechlanguage pathology at Old Dominion University.

Caitlyn Sullivan graduated from Christopher Newport University in 2019 with a Bachelor of Arts in Psychology and minors in Leadership Studies and Childhood Studies. She continued at CNU for her Master of Arts in Teaching for Elementary Education and graduated in 2020. While at CNU, Caitlyn was involved in the President Leadership Program, Greek life, Psi Chi, SVEA, and Undergraduate Research. Caitlyn also served the Newport News community through over 100 hours within the Newport News Public School system.

Erin Mills is a senior psychology major with a minor in leadership studies. In August, she will be participating in the Disney College Program in Orlando, Florida.

Brittany Rininger graduated from Christopher Newport University in May of 2019. She is currently working towards her Masters of Arts in Special Education at Arizona State University. Additionally, she is working as a Registered Behavior Technician providing in-home ABA services.

Ayesha Ferozpuri is a Christopher Newport University alumna with a Bachelor of Science in Neuroscience and Psychology. She currently works at Solstice East, a residential treatment center for adolescent girls, as a personal development mentor. In the fall, she will be pursuing her Masters in rehabilitation and mental health counseling at Virginia Commonwealth University.

This poster was accepted for presentation at the 66th Annual Meeting of the Southeastern Psychological Association.

Dwell Time Differs as a Function of Emotion and Social Anxiety Levels

Department of Psychology

Abstract

We explored the potential relationship between social anxiety and various emotions used for facial expression processing. Social anxiety differentiates among certain emotional face processing in child faces only. Specifically, dwell time was greater when processing child faces expressing anger and fear among high socially anxious participants compared to low socially anxious ones. When presented with faces of different ages and emotions, social anxiety impacts how individuals process the emotional expressions of children faces but not adult faces.

Importance of the Research

● Individuals with social anxiety may have a heightened sensitivity to emotions in general (Horley, Williams, Gonsalvez, & Gordon, 2004; McTague et al., 2017)

● Those individuals with higher social anxiety levels tend to have a longer dwell time for fearful expressions, than those with lower social anxiety levels. (Schofield, Johnson, Inhoff, & Coles, 2012)

● Avoidance of aversive facial expressions such as anger and fear could be caused by an evolutionary need to minimize threats from others (Horley et al., 2004).

● In the current study we use eye-tracking technology to examine the visual processing of anger, fear, happiness, neutral, and sadness in individuals with high and low social anxiety scores.

Participants and Procedure

● 46 undergraduate students from Christopher Newport University

● Participants viewed an 80 slide presentation of faces, taken from CAFE child facial set (LoBue & Thrasher, 2014) and NimStim adult facial set (Tottenham et al., 2009) while measures of eye-tracking were documented using Tobii X3-120.

● Participants were instructed to label the faces with the appropriate emotion.

● Participants were asked to complete the Liebowitz Social Anxiety Scale which was used for grouping purposes. Participants were grouped into two groups based on low, less than 55, and high, greater than 55 scores.

Findings

Results

A 2 (SAS high or low) X 2 (age of face) X 5 (emotion)X 4 (AOI) ANOVA was conducted

3-way interaction effects found for visit duration F(4, 176) = 2.736, p = 0.030. See Effects included age of face, emotion, and high or low social anxiety group classification

Interpretation

Participants in this study scored within the clinical range for Social Anxiety. Individuals with high social anxiety spent more time processing faces expressing anger and fear, compared to happiness, sadness, Most importantly, participants who have high social anxiety spent more time processing child faces expressing anger. Perhaps, college students are not regularly exposed to children expressing anger. Thus, it takes longer for the emotion processing to occur because it is an unfamiliar event.

○ Individuals with high social anxiety may be intimidated by unfamiliar people expressing anger. Our stimuli were unfamiliar to our participants. Participants spent less time exploring adult faces displaying anger. With child faces expressing anger, on the other hand, there may be a less intimidation factor, so they may spend longer exploring those faces.

Big Picture

Individuals with high and low social anxiety visually process emotional expressions differently.

When processing anger, our findings support an evolutionary need to protect ourselves from threats which are likely to come from adults rather than children. Thus, spending more time exploring a child face expressing anger is less threatening.

4
Kali DeBorde, Caitlyn Sullivan, Erin Mills, Brittany Rininger, Ayesha Ferozpuri, & Laurie Hunter
Research Lab
(LoBue & Thrasher, 2014)
Face Processing

Autonomic Correlates of Mental Toughness

Christopher Duncan

Faculty Sponsor: Dr. Lindsey Stone, Department of Psychology

Abstract

Mental toughness is a key variable in determining how individuals react to and cope with stressful situations. Current research relies on subjective self-report measures to measure mental toughness, and few objective indices have been explored. However, many links exist between mental toughness and other constructs relating to emotion regulation and mental health which demonstrate relationships with autonomic nervous system activity. Low resting parasympathetic (PNS) activity is related to emotion dysregulation and psychopathological disorders, while high sympathetic (SNS) activity is also implied in negative mental health outcomes. At present, ANS indices are generally examined separately. However, measures like Cardiac Autonomic Balance (CAB) and Cardiac Autonomic Regulation (CAR) which examine the relative contribution

of each branch of the ANS may yield stronger insights than measured examined in isolation. The goal of this study is to determine a relationship between physiological measures of nervous system arousal and mental toughness. Both single-branch measures of autonomic nervous system activity (heart rate variability and pre-ejection period) and composite indices (CAB and CAR) were examined. Thirty female undergraduates provided physiological data and responses to self-report questionnaires measuring mental toughness. Results found a significant positive relationship between CAB and MT, but not with CAR, HRV, or PEP. Results support the utility of composite indices of ANS activity as a predictor of MT above individual indices. Implications for educational, clinical, and vocational settings are discussed.

Keywords: Mental toughness, autonomic nervous system, heart rate variability, pre-ejection period, cardiac autonomic balance

Christopher Duncan is a recently graduated senior with a B.A. in Psychology from Christopher Newport University. During his time at CNU, he was involved with the President’s Leadership Program, the Honors Program, and ROTC. He worked as a research assistant in the RAD Lab with Dr. Stone in the Department of Psychology for three years, where he conducted independent research on Mental Toughness. Following graduation, he will serve as an Army Officer, where he one day intends to pursue his PhD in Psychology to continue his research on Mental Toughness and apply his findings to military settings.

C

Physiological Correlates of Mental Toughness

Method

Background

• Mental toughness (MT) is a personality trait which determines how effectively one handles stress and pressure but is typically only measured with self-report data.

• High MT is associated with lower rates of mental disorders like depression, anxiety, and PTSD, and the use of adaptive emotion regulation strategies, implying that mentally tough individuals are better poised to regulate their emotions, thus avoiding negative mental health outcomes.

• The autonomic nervous system (ANS) activity is heavily implicated in mental health, emotion regulation, and stress response. While indices that measure each branch of the ANS in isolation are useful, examining how the branches work together may yield greater insights

• Individuals with low parasympathetic (PNS) activity and high sympathetic (SNS) activity at baseline may be more prone to deficits in emotion regulation and mental disorders. Cardiac Autonomic Balance (CAB) measures the relative contribution of each branch of the ANS and determines PNS or SNS dominance at baseline.

Aim & Hypotheses

• In summary, mental toughness is associated with effective emotion regulation strategies and lower risk for internalizing psychopathology, both of which may be assessed via the ANS.

• The goal of the current study was to determine objective, autonomic correlates of mental toughness.

• We hypothesize that higher Mental Toughness will be associated with higher Cardiac Autonomic Balance, indicating parasympathetic dominance.

• We hypothesize that CAB will be a stronger predictor of MT than individual SNS or PNS indices

Participants

• 49 female undergraduates in a campus sorority

• 14 excluded for medications that affect ANS activity, caffeine, or alcohol consumption

• 5 excluded for non -usable physiological data

• N=30 total participants

Procedure

After providing consent and filling out self -report surveys, physiological data was collected via MindWare device while the participants watched a 5 -minue nature video. PNS activity was measured via HRV, or the variability in time between heart beats. SNS activity was measured via PEP, or the time between the depolarization of the left ventricle and the opening of the aortic valve. CAB was calculated by subtracting normalized PEP values from normalized HRV values. Thus, positive CAB scores denotes PNS dominance and negative CAB indicates SNS dominance.

Since BMI and respiration rate can influence HRV, these variables were considered during analyses. HRV was recalculated by regressing respiration rate on HRV, then averaging HRV residuals. Multiple regression was run to covary for BMI.

Assessing Mental Toughness: The MTQ -18 survey consists of 18 questions, scored on a Likert scale. Responses ranged from 1 (Strongly Disagree) to 5 (Strongly Agree). It includes items such as “Even when under considerable pressure I usually remain calm”

Results

H1: Supported Initial bivariate correlations between CAB and MT trended toward significance p =.054 When adjusting for respiration rate, the relationship was strengthened p =.043 . Covarying for BMI still approached significance, p =.067.

RAD-Lab Relationships in Adolescent Development

Discussion

• Higher MT was associated with higher Cardiac Autonomic Balance

• CAB was a significant predictor of MT while isolated ANS indices were not

• Results are the first to demonstrate autonomic correlates of MT, filling a notable gap in the literature

• Results align with the idea that the relationship between the branches of the ANS extends our understanding past what is possible with isolated ANS indices

• Study was limited by a small sample size, leading to an increased risk of Type II error. We are confident interpreting marginally significant results due to similar effect sizes across all tests.

• In summary, results suggest that mentally tough individuals may be parasympathetically dominant at rest, with implications for mental health and emotion regulation, and applications in high -risk professions, education, and clinical settings.

Contact: Lindsey.stone@cnu.edu

Study funded by OURCA Research LENS Grant

References

1 Clough, P., Earle, K., & Sewell, D. (2002). Mental Toughness: The Concept and Its Measurement. Solutions in Sports Psychology 1(1), 32-45.2 Cohen, S., & Wills, T. A. (1985). Stress, social support, and the buffering hypothesis. Psychological bulletin, 98(2), 310.

2 Berntson G. G., Norman, G. J., Hawkley, L. C., & Cacioppo, J. T. (2008). Cardiac autonomic balance versus cardiac regulatory capacity. Psychophysiology, 45(4), 643-652.

3 McCorry L. K. (2007). Physiology of the autonomic nervous system. American journal of pharmaceutical education, 71(4), 78. https://do i.org/10.5688/aj710478

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4 Stone, L. B., McCormack, C. C., & Bylsma, L. M. (2020). Specific alterations in autonomic balance predict depression and anxiety symptoms among young adult women. Manuscript submitted for publication. Associations between Attentional Control, Brooding, & Anxiety & Depressive Sx *p < 0.05, **p < 0.01, ***p < 0.001 Linear Regressions (β) EATQ: Attention CRSS: Brooding SCARED MFQ EATQ: Attention 1 -.29** -.31** -.46*** CRSS: Brooding -.29** 1 .42*** .53*** SCARED -.31** .42*** 1 .53*** MFQ -.46*** .53*** .53*** 1 Partial Correlations (s) (controlling for age and gender) EATQ: Attention CRSS: Brooding SCARED MFQ EATQ: Attention 1 -.29* -.34** -.45*** CRSS: Brooding -.29* 1 .43*** .54*** SCARED -.34** .43*** 1 .54*** MFQ -.45*** .54*** .54*** 1
HRISTOPHER
UNIVERSITY
H2: Supported CAB was a significant predictor of MT while both PEP and HRV failed to demonstrate significant associations.
NEWPORT
Figure 1: Relationship between CAB and MT
CAB Correlations between MT and Autonomic Indices Bivariate (r) Respiration Rate (r) Multivariate (β) MT-18 MT-18 MT-18 PEP 0.218 -HRV 0.048 0.076 0.066 CAB 0.355 .372* 0.354 Note: PEP: Pre-ejection period. HRV: Heart rate variability. CAB: Cardiac autonomic balance. MT-18: Mental Toughness. Multivariate analyses covary for BMI. Respiration rate: bivariate analyses re-run with respiration rate regressed on HRV *p<.05 Table 1 R 2= .12
Mental Toughness

Effects of Stress on Behavioral Inhibition in Male and Female Rats Tested via Operant Touchscreen Chambers

Abstract

Addiction is a disease that changes behavior in negative ways including a compulsion to seek addictive substances, despite recurring negative consequences. Addiction can disrupt the healthy function of a body, and can affect people differently (ASAM, 2011; NIDA, 2014). Evidence suggests that there is a sex difference related to drug addiction, such as the intensity of addiction, withdrawal symptoms, and likelihood of relapse (Becker & Chartoff, 2019). The present study was designed to investigate how stress affects the spontaneous recovery of a previously extinguished appetitively-conditioned touchscreen response in male and female rats. In this experiment, spontaneous recovery models relapse to addiction after a period of abstinence. The rats underwent acquisition training, extinction training followed by a retention interval, and then finally, a spontaneous recovery test. A (Sex: male vs female; by Stress: stress vs no stress; by Block: 10-trial blocks) repeated measures ANOVA indicated a within-subject effect of blocks during spontaneous recovery test [F(5, 60) = 15.9, p < 0.01] suggesting that the percent Conditioned Response

(CR) significantly decreased across trials in all rats. There was also a significant Stress by Block interaction [F (5, 60) = 3.86, p < 0.01]. Follow-up analysis showed that both male and female rats that were exposed to an acute stress prior to the spontaneous recovery test had significantly greater CR percentages on block one [F (1, 12) = 13.11, P < 0.01] and on block two [F (1, 12) = 17.79, p < 0.01] compared to non-stressed rats. We found that acute stress significantly reduced inhibition of previously extinguished conditioned touchscreen responses in males and females. These results suggest that stress impairs the ability to inhibit a previously learned behavior. Interestingly, our data showed high variability in conditioned responding in female rats that received stress exposure. It is possible that stress effects in female rats are dependent on the fluctuating levels of estrogen across the different phases of their natural estrous cycle. Further studies will include using ovariectomized rats replaced with estrogen to test the interactive effects of estrogen and stress on behavioral inhibition.

Sarah Goldsmith is a member of the Christopher Newport University Class of 2021. She is majoring in Neuroscience and is pursuing minors in both Biology and Leadership Studies. At CNU, Sarah is involved in Dr. Lipatova’s Hormones and Behavior research lab, a member of the President’s Leadership Program, a sister of Delta Gamma Women’s fraternity, and a participant of REACH alternative breaks for which she also serves as the President. Following graduation, Sarah aspires to enter a PhD program so she can continue doing research. Ideally, she would like to conduct research in the field of Neuroendocrinology.

Emery Harlan plans to graduate from Christopher Newport University with a Bachelor of Science in both Neuroscience and Psychology in May 2022. While attending CNU, he became a member of Dr. Lipatova’s Hormones and Behavior research lab. Emery became interested in Neuroscience and Psychology after completing AP Biology and CIS Psychology in high school, and he currently plans to attend graduate school for a PhD after graduation.

Susannah Garber is a member of the Christopher Newport University class of 2022. She is majoring in Cellular, Molecular, and Physiological Biology, with a double minor in Leadership and Chemistry. Since coming to CNU she has become a part of Dr. Lipatova’s Hormone and Behavior Research Lab. She is also involved in Cru, Take Note A Cappella, and regularly volunteers with Riverside Regional Medical Center. After graduation, she plans to attend graduate school and pursue her PhD.

This poster was accepted for presentation at the 125th Annual Meeting of the Eastern Psychological Association.

Effects of Stress on Behavioral Inhibition in Male and Female Rats Tested via Operant Touchscreen Chambers

RESULTS

stress-dependent (Lynch et al. 2002; McKay et al, 1996).

• The purpose of the present study was to examine the effects of acute stress on inhibition of an appetitively conditioned touchscreen response in male and female rats.

• Extinction training was used because it is known to produce inhibition of a reward-seeking responding (Todd et al, 2014).

• A spontaneous recovery test was used to measure behavioral inhibition (Brooks & Bouton, 1993).

Subjects & Apparatus Sprague Dawley rats (16 male; 16 female) were trained and tested in Layfette Touchscreen Chambers using ABET II software.

Pre-training

During a 60 min pre-training session, rats were presented with a conditioned stimulus (CS; i.e., a white square) every 30 secs followed by one 45 mg sucrose pellet. However, if the rat touched the CS it received three sucrose pellets.

Acquisition

During acquisition, rats were given 100 presentations of the CS per daily session. If the rat touched the CS it received a sucrose pellet. Incorrect responses were followed by the house-light turning on for 10 secs and no reward was given. The acquisition criterion was 80% correct conditioned touch responses (CR) within a single session.

Extinction & Spontaneous Recovery

METHODS Acquisition Spontaneous Recovery * * *

During extinction, the rats were not reinforced (i.e., no food was given) for a touching the CS. Extinction consisted of 60 trials per session. The criterion was 77% no-CRs within a single session. Spontaneous recovery was tested two weeks after the rat reached extinction criterion.

Acute stress administration

Half of the male and half of the female rats received a 30 min acute restraint stress (outside of the training chambers) immediately prior to the spontaneous recovery test.

RESULTS AND DISCUSSION

conditioned touch response to the CS that was presented on a touchscreen.

• There were no sex differences in the rate of acquisition or extinction.

• Stressed rats showed greater spontaneous recovery than non-stressed controls.

• A repeated measures mixed ANOVA revealed a significant Block X Stress interaction [F (5, 140) = 5.1, p < 0.01].

• 2 x 2 ANOVAs revealed significant main effects of stress on Block 1 [F (1, 28) = 5.25, p = 0.03] and Block 2 [F (1, 28) = 5.98, p = 0.02].

• Stressed female rats showed the greatest spontaneous recovery overall, however their performance was highly variable.

• Our results show that stress decreases inhibition, which may be a possible mechanism that contributes to stress-induced drug relapse.

Future Studies

We plan to use a similar experimental approach to determine if fluctuations in estrogen levels differentially affect the magnitude of spontaneous recovery in stressed and non-stressed female rats.

Bouton, M. E., Winterbauer, N. E., & Todd, T. P. (2012). Relapse processes after the extinction of instrumental learning: Renewal, resurgence, and reacquisition. Behavioural Processes, 90(1), 130-141.

Brooks, D. C., & Bouton, M. E. (1993). A retrieval cue for extinction attenuates spontaneous recovery. Journal of Experimental Psychology: Animal Behavior Processes, 19(1), 77-89.

Bussey, T. J., Padain, T. L., Skillings, E. A., Winters, B. D., Morton, A. J., & Saksida, L. M. (2008). The touchscreen cognitive testing method for rodents: How to get the best out of your rat. Learning & Memory, 15(7), 516-523.

Lynch, W. J., Roth, M. E., & Carroll, M. E. (2002). Biological basis of sex differences in drug abuse: Preclinical and clinical studies. Psychopharmacology, 164(2), 121-137.

Mar, A. C., Horner, A. E., Nilsson, S. R., Alsiö, J., Kent, B. A., Kim, C. H., Holmes, A., Saksida, L. M., & Bussey, T. J. (2013). The touchscreen operant platform for assessing executive function in rats and mice. Nature Protocols, 8(10), 1985-2005.

McKay, J. R., Rutherford, M. J., Cacciola, J. S., Kabasakalian-McKay, R., & Alterman, A. I. (1996). Gender differences in the relapse experiences of cocaine patients. The Journal of Nervous and Mental Disease 184(10), 616-622.

National Institute on Drug Abuse. (2007, April). Drugs, Brains, and Behavior The Science of Addiction. Retrieved from https://www.drugabuse.gov/sites/default/files/soa_2014.pdf

Todd, T. P., Vurbic, D., & Bouton M., E. (2014). Behavioral and neurobiological mechanisms of extinction in Pavlovian and instrumental learning. Neurobiology of Learning and Memory, 108, 52-64.

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REFERENCES Extinction

The Influence of the Dark Tetrad Personality

Traits on Cyberbullying Behavior

Katelyn Hark

Faculty Sponsor: Dr. Gayle Dow, Department of Psychology

Abstract

PANDEMIC 2020: With the suddenly thrust into the world of online education, bullying behavior has not stopped. Victims now find bullies in their in their digital classrooms, at their graduations, in their private homes, in their living rooms, in their bedrooms. While educators acknowledge this is a growing problem, there is little research into the causes and motivations of cyberbullying. Malevolent personality factors, such as the Dark Tetrad, which includes narcissism, psychopathy, Machiavellism, and sadism, could be one cause of cyberbullying. The purpose of this study was to investigate the

relationship among the Dark Tetrad, cyberbullying behavior, and victimization. Two hundred twenty-seven participants completed assessments on Paulhus’ (2002) Dark Triad, DelRay (2015) European Cyberbullying Intervention Project Questionnaire. A univariate analysis of variance (ANOVA) indicated the findings were significant be F(1,205)= 4.25, np2= 0.02, power=0.53, p=.044. Sadists perpetrated cyberbullying than all others. It is believed this is due to their not only their lack of empathy but their enjoyment in hurting others. Implications and limitations will be discussed.

Katelyn Hark is from Richmond, Virginia and is a senior at Christopher Newport University. She is currently pursuing a Bachelor of Science degree in Psychology and minoring in Leadership Studies and U.S. National Security Studies. During her time at Christopher Newport, she is a part of the President’s Leadership Program, Women’s Club Lacrosse Team, and Phi Mu Fraternity, where she serves on the chapter’s executive board as Secretary. Her research with Dr. Dow primarily focuses on malevolent personality traits, such as the Dark Tetrad.

The Influence of Dark Tetrad Personality Traits on Cyberbullying Behavior

Katelyn Hark

Faculty Sponsor Gayle T Dow, PhD

Christopher Newport University

Abstract

PANDEMIC 2020: With the suddenly thrust into the world of online education, bullying behavior has not stopped. Victims now find bullies in their in their digital classrooms, at their graduations, in their private homes, in their living rooms, in their bedrooms. While educators acknowledge this is a growing problem, there is little research into the causes and motivations of cyberbullying. Malevolent personality factors, such as the Dark Tetrad, which includes narcissism, psychopathy, Machiavellism, and sadism, could be one cause of cyberbullying. The purpose of this study was to investigate the relationship among the Dark Tetrad, cyberbullying behavior, and victimization. Two hundred twenty-seven participants completed assessments on Paulhus’ (2002) Dark Triad, DelRay (2015) European Cyberbullying Intervention Project Questionnaire. A univariate analysis of variance (ANOVA) indicated the findings were significant be F(1,205)= 4.25, np2= 0.02, power=0.53, p=.044. Sadists perpetrated cyberbullying than all others. It is believed this is due to their not only their lack of empathy but their enjoyment in hurting others. Implications and limitations will be discussed.

Introduction

The Dark Tetrad is comprised of four personality traits: Machiavellianism, narcissism, psychopathy, and sadism (Brown, Hartay, & Palasinski, 2019). These traits are characterized by their lack of empathy and are considered “socially aversive” personality traits (Pahaulus & Williams, 2002). This lack of empathy experienced allows individuals to manipulate others or cause pain with little regard towards their victim.

Cyberbullying is considered a form of bullying that uses unwanted repetitive, intentional, and harmful behaviors online towards another person (Patchin & Hinduja, 2015). Cyberbullying ranges from hate speech, intimidation and threats to hacking and identify theft. Cyberbullying occurs at all ages, but given the limited coping mechanism of youth, it can be particularly harmful to teens and young adults. While safeguards can be put in place to limit the prevalence of cyberbullying, there is little research on the motivations of a cyberbully to engage in harmful behavior.

Sadism

Enjoying the pain and humiliation of others.

Psychopathy

Lack of empathy, remorse, and experiences no fear of consequences.

Machiavellianism

Deceiving and exploiting others for personal gain.

Narcissism

Having a sense of entitlement and disregard for others.

Methodology

Participants in this study were recruited from a small liberal arts school in the United States through an online research portal. A total of 226 participants (42 men and 184 women) were included in the sample. Participants completed Paulhus’ (2002) 27-item Dark Triad assessment which consisted of statements describing different thoughts or behaviors that are associated with the dark triad personalities, such as “Whatever it takes, you must get the important people on your side”, “I know that I am special because everyone keeps telling me so”, and “Payback needs to be quick and nasty.” In order to measure sadism, participants took O’Meara’s 10-item Short Sadistic Impulse Scale assessment, which also consisted of statements describing different thoughts or behaviors, such as “I have hurt people because I could.” These two assessments were measured using a 5 point Likert-type scale with the options of strongly agree, agree, neutral, disagree, and strongly disagree. Cyberbullying behavior was measured using DelRay’s (2015) European Cyberbullying Intervention Project Questionnaire, which measured both cyberbullying perpetration and victimization behaviors, such as “Someone posted embarrassing videos or pictures of me online” and “I said nasty things about someone to other people either online or through text messages.” This questionnaire was measured using a 5 point Likert-type scale that measured the number of instances this behavior occurred, with the options of never, once or twice, once a month, once a week, and more times a week.

Results and Implications

It was hypothesized that higher levels of Machiavellianism, psychopathy, and sadism would indicate higher levels of cyberbullying behavior, while narcissism would not indicate higher levels of cyberbullying behavior. Results found that only higher levels of sadistic behavior was significant and was associated with higher levels of cyberbullying behavior F(1,205)= 4.25, , np2 = 0.02, power=0.53, p=.044. This finding could be explained that sadists find enjoyment out of hurting others much more than Machiavellians, narcissists, and psychopaths. Cyberbullying may allow perpetrators to hurt someone anonymously without having to do it face-to-face, making it easier for them to inflict pain and avoid consequences. With the rise of online communication, it is important to understand the motivations behind cyberbullying, especially in young adults and adults.

This research can explain that someone’s personality is the reasoning behind engaging in cyberbullying. These findings can help the schools, universities, and work places in implementing new guidelines or procedures in order to combat cyberbullying. These can also assist future research in determining the progression of cyberbullying from childhood, and what personality traits are more likely to continue this behavior into adulthood.

References

Brown, W. M., Hazraty, S., & Palasinski, M. (2019). Examining the dark tetrad and its links to cyberbullying. Cyberpsychology, Behavior, and Social Networking, 22(8), 552–557.

Paulhus, Delrol L., & Williams, K M. (2002). The Dark Triad of Personality: Narcissism, Machiavellianism, and Psychopathology. Journal of Research in Personality, 36, 556563. Academic Press.

Del Rey, R., Casas, J. A., Ortega-Ruiz, R., Schultze-Krumbholz A., Scheithauer, H., Smith, P., Thompson, F., Barkoukis, V., Tsorbatzoudis, H., Brighi, A., Guarini, A., Pyżalski J., & Plichta, P. (2015). Structural validation and cross-cultural robustness of the European Cyberbullying Intervention Project Questionnaire. Computers in Human Behavior, 50, 141–147.

O'Meara, A., Davies, J., & Hammond, S. (2011). The psychometric properties and utility of the Short Sadistic Impulse Scale (SSIS). Psychological Assessment, 23(2), 523–531.

Patchin, J.W., & Hunduja, S. (2015). Measuring Cyberbullying: Implications for Research. Aggression and Violent Behavior 23, 69-74.

Picture 1 (top): https://www.health.harvard.edu/preventing-cyberbullying

Picture 2 (middle): https://turbofuture.com/internet/Cyberbullying-and-Social-Media

Picture 3 (bottom): https://www.cybersmile.org/advice-help/category/advice-for-adults

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Figure 1. Dark Tetrad on Cyberbullying

Processing and Visualization of EEG Data Using EEGLAB

Creid Johnson

Faculty Sponsor: Dr. Iordanka Panayotova, Department of Mathematics

Abstract

The purpose of this research project was to demonstrate the advanced signal processing of capabilities of EEGLAB and its applicability to electrical signal processing. EEGLAB is able to collect and process signal data, develop 2D and 3D simulations of electrical signals in the brain, and separate signals into independent components. By demonstrating how EEGLAB can be used in advanced signal processing, signal processing researchers are able to visualize and understand how EEGLAB would benefit them in processing signal data. EEGLAB provides researchers with several options in modeling, simulating, and presenting their signal data. EEGLAB has an Independent Component Analysis (ICA decomposition) algorithm feature for separating signals into independent components. Before EEGLAB was implemented, researchers were only able to use the averages of the ERP waveforms to calculate signal properties. Event-related dynamics aren’t always accounted for in these plots. Also, ongoing EEG processes that may be time or phase-locked are also ignored in averaging ERP waveforms. So, ICA decomposition must be applied to ensure that

signal plots and data interpretation are correct. For the research project, an experiment was conducted in order to better understand how social categorization affects face processing. In this experiment, participants had electrodes placed on their scalps to monitor signal activity. Individuals were given faces to memorize while completing an age or sex categorization task. A fixation cross was presented in the middle of the screen between face stimuli. The signal and eye movement data were recorded and processed using EEGLAB. Signal data was collected from 64 scalp channels. An ICA algorithm was then used to separate the signals into independent components. After applying the ICA algorithm, the component ERP image and spectra were able to be plotted. The independent components were used to show concentrated regions of brain activity. Signal concentrations were used to show the greatest source of signal activity and main signal type in specific brain regions. This would be very beneficial in monitoring for epileptic seizures, mental disorders, and other brain irregularities.

Creid Johnson is a student, at Christopher Newport University, pursuing a B.S. in Electrical Engineering. He plans to earn his master’s degree, in Electrical Engineering, and pursue a career in developing advanced satellite communication systems. On campus, he is a part of CNU’s Unmanned Aerial Systems Team that is dedicated to develop durable aircraft systems and drones. Besides designing wireless communication systems for drones, he is also pursuing research in developing programs capable of sensing turbulent wind patterns around airborne drones. These turbulent patterns would then be used in developing an autopilot system capable of rotating the drones to continue flying through unexpected wind conditions. Through CNU’s Signals and Systems course, he was introduced to basic signal properties, characteristics and its importance in neuroscience, psychology, and electrical engineering.

Processing and Visualization of EEG Data Using EEGLAB

Creid Johnson

Faculty Sponsor: Dr. Iordanka Panayotova

Department of Mathematics, Christopher Newport University

Background

❑ What is EEG data?

An EEG is a test that detects electrical activity in the brain using small, metal discs (electrodes) attached to the scalp. The brain cells communicate via electrical impulses and are active all the time, even when the brain sleeps, and their activity shows up as wavy lines on an EEG recording.

Methods and Materials

Project Objectives : The purpose of this project was to demonstrate the advanced processing capabilities of EEGLAB and its applicability to electrical signal processing.

Materials : The EEG data used for this research came from a study of Dr. Rollins (Rollins et. Al. 2020). In this study, the researchers wanted to better understand how social categorization affects face processing. In the experiment, the participants were given images of faces to memorize while completing either an age or sex categorization task. Electrodes were placed on their scalps to record electrical signal activity. A fixation cross was presented in the middle of the screen between face stimuli.

Conclusions

 EEGLAB is a MATLAB plug-in and has many signal processing capabilities. EEGLAB can collect and process signal data, develop 2D and 3D simulations of signal activity in the brain, and separate different types of signals. This provides researchers with several different options in modeling, simulating, and presenting signal data.

(EEGLAB, 2016)

❑ Traditional analysis of event-related EEG data

The first approach is in the time-domain, where researchers average a set of data trials or epochs time-locked to some class of events, yielding an ERP waveform at each data channel, which represents an average signal. The second approach is in the frequency-domain, where researchers average changes in the frequency power spectrum of the whole EEG data time locked to the same events, producing a two-dimensional image that is call the event related spectral perturbation. (Makeig et. Al. 2004)

❑ What is EEGLAB and why to use it?

EEGLAB is a MATLAB toolbox made by Arnold Delorme and Scott Makeig. It is used to separate signals from noise, take continuous signals and separate them into components, and plot signal processes. Before EEGLAB was created, researchers were only able to take the average of the ERP waveforms to draw their conclusions. The problem with this is that event-related dynamics aren’t always accounted for in these plots. It ignores ongoing EEG processes that may be partially time and phaselocked by experimental events. An important part of EEGLAB is Independent Component Analysis (ICA decomposition). ICA is used to separate a signal into independent signals. This is very useful in monitoring brain signals for specific regions. These recorded signals are then used to monitor for signal irregularities or potential mental problems.

Methods : EEGLAB was used to process the signal data from the experiment. Data was collected into 64 scalp channels and these figures were created based on averaged event-related potential waveforms. An ICA algorithm was used to separate the signal data. EEGLAB was then able to generate the different signal graphs from the ICA decomposition.

RESULTS/GRAPHS

 EEGLAB has an interface for selecting the different signal components. So, researchers do not need experience in programming to get signal processing results. EEGLAB is a powerful tool for signal processing.

 ICA decomposition is only available through EEGLAB’s toolbox. ICA is used to separate signals from each other. Often, signals from recorded data have noise or interfering signals in them. In order to get the correct interpretation of the signal data, researchers use ICA decomposition. So, EEGLAB offers advanced signal processing techniques that are freely accessible.

References

1. Makeig, S., Debener, S., Onton, J., Delorme, A. Mining event-related brain dynamics. Trends Cogn Sci 8:204-10, 2004.

2. Rollins, Leslie, et al. “Social Categorization Modules Own-Age Bias in Face Recognition and ERP Correlates of Face Processing.” Neuropsychologica, 2020.

3. “EEGLAB Workshop San Diego 2016: ICA decomposition theory & evaluation.” YouTube, uploaded by Swartz Center for Computational Neuroscience, UCSD, 1 February 2017, https://www.youtube.com/watch?v=EbINZTfN8-I

 From Left to Right: Specific Power of Brain Signals through component 1, The Largest ERP Components of the Collected Signals, Scalp Maps for 12 electrodes, Spectral Density for Component 1, Scalp Maps for the First 5 Components, Corresponding Signals to Each Channel

 These graphs represent the strengths of the averaged electrical signals within the brain. The color spectrum is used to indicate the distribution of electrical activity across the scalp. This could be very beneficial in monitoring for irregularities in the brain, epileptic seizures, and mental disorders.

Acknowledgments

This project was funded by the Research Apprentice Program of the Office of Undergraduate Research and Creative Activity at Christopher Newport University. The author is thankful to Dr. Rollins for providing the data and constructive comments on the manuscript.

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Figure Schematic representation of the electrode configuration placed on an individuals’ scalp in relation to the brain signals.

Effect of encoding variability on mnemonic discrimination: An ERP study

Faculty Sponsor: Dr. Leslie Rollins

Mnemonic discrimination is the ability to distinguish between similar stimuli. Huffman and Stark (2017) assessed this ability by developing the forced-choice Mnemonic Similarity Task (MST). The task involves three conditions: A-X (target paired with novel object), A-A′ (target paired with similar lure), and A-B′ (target paired with different lure). Performance is best for A-X condition, followed by A-A′ condition, then A-B′ condition (Huffman & Stark, 2017; Rollins et al., 2019). A previous eye-tracking study revealed that errors on A-B′ trials were associated with more fixations to the B stimulus than the A stimulus at encoding (Rollins et al., 2019). The current project seeks to examine whether encoding variability, as indexed by electrophysiological brain activity, explains performance on the forced-choice MST. Friedman and Johnson (2000) found that items subsequently recognized elicit a larger amplitude ERP response during memory encoding compared to those later forgotten at retrieval. Therefore, we hypothesize that accuracy will interact with the stimulus such that incorrect A-B′ trials will be associated with a higher mean amplitude to the stimulus B than the A

stimulus during encoding. However, correct A-B′ trials will either be associated with a higher mean amplitude to the A stimulus than the B stimulus during encoding or there may be no difference in the amplitude of the waveforms. Eighteen young adults (15 females, 3 males) completed a modified version of the forced-choice MST and provided a sufficient number of ERP trials for the following conditions: A-A′ correct A-A′ incorrect, A-B′ correct, and A-B′ incorrect. Behaviorally, individuals performed better in the A-A′ condition than the A-B′ condition. Baseline-corrected mean amplitudes 500-700 ms poststimulus onset were exported and analyzed using a 2 Stimulus (A, B) x 2 Accuracy (Incorrect, Correct) x 3 Coronal (F, C, P) x 3 Sagittal (Left, Middle, Right) repeated-measures ANOVA. Consistent with our hypothesis, the mean amplitude elicited to the B stimulus was larger than the A stimulus when individuals subsequently responded incorrectly and larger to the A stimulus than the B stimulus when individuals subsequently responded correctly. These findings suggest that encoding variability accounts for performance on the forced-choice MST.

Alexis Khuu is member of the class of 2020 at Christopher Newport University with a Bachelor of Science in Neuroscience and Psychology. Her achievements earned her membership in Alpha Chi Honor Society and Nu Rho Psi Honor Society. While at the University, she conducted research in the Developmental Cognitive Neuroscience Laboratory with Dr. Leslie Rollins, participated in the Research Apprentice Program, presented at the Paideia Undergraduate Research Conference, and co-authored a manuscript that was published in July 2019. Alexis expanded her research involvements beyond the University as a volunteer research trainee at the Center for Autism Spectrum Disorders at Children’s National Hospital. To further her contributions to the scientific community, she aspires to pursue a doctorate in clinical psychology.

Katherine Goida is a member of the class of 2021 at Christopher Newport University. She is majoring in Neuroscience and pursuing a minor in Leadership Studies. Katherine is part of the Honors Program, President’s Leadership Program, Alpha Chi

Honors Society, Omicron Delta Kappa Leadership Honors Society and has completed the Research Apprenticeship Program during the 2019-2020 academic year. After graduation, she hopes to attend graduate school to pursue a master’s program focused on applied behavioral analysis (ABA) and wants to become an ABA therapist for children with disabilities.

Natasha Woods is a member of the class of 2020 at Christopher Newport University. She majored in Neuroscience and pursued a minor in Biology. She currently works at McDonalds as a Department Manager. In addition, is pursing many job opportunities around the Hampton Roads area. She is hoping to pursue a Master’s in Public Health in Fall 2020. She enjoys spending time with her family and watching scary movies.

Dr. Rollins is an Assistant Professor of Psychology and Neuroscience. Her research focuses on the development and neural bases of memory.

Abstract This poster was accepted for presentation at the 66th Annual Meeting of the Southeastern Psychological Association.

Effect of encoding variability on mnemonic discrimination: An ERP study

Alexis Khuu, Katherine Goida, and Natasha Woods Faculty Sponsor: Dr. Leslie Rollins

Christopher Newport University

• Mnemonic discrimination refers to the ability to distinguish between previously encountered and novel stimuli

• Forced-choice assessment of mnemonic discrimination

• Huffman and Stark (2017) developed the forced-choice Mnemonic Similarity Task (MST), which included three test formats: (A-X), (A-A’), and (A-B’). A was the target, X was an unrelated lure, A’ was a similar lure, and B’ was a non-corresponding lure Mathematical models suggested that encoding variability may account for errors, especially on the A-B’ test format. Specifically, errors (i.e., selecting B’ stimulus, which was a lure, rather than the A stimulus, which was a target) may be due to the enhanced encoding of the B stimulus than the A stimulus at encoding. A previous eye-tracking study in the lab provided support for this hypothesis (Rollins et al , 2019)

• The goal of the present study was to examine whether encoding variability, as indexed by electrophysiological brain activity, explains performance on the forced-choice MST.

• Hypotheses:

• We hypothesized that participants would perform best in the A-A’ condition compared to the A-B’ condition (Huffman & Stark, 2017; Rollins et al , 2019)

• Given the subsequent memory effect (Friedman & Johnson, 2000) is typically larger for subsequently recognized than forgotten stimuli, we hypothesized that

• On incorrect A-B’ trials, mean amplitudes would be higher for the B stimulus than the A stimulus

• On correct A-B’ trials, mean amplitudes would either be higher for the A stimulus than the B stimulus or display no difference between the two stimuli

Methods Participants

• At retrieval, participants were presented with 192 trials. For each trial participants viewed two images and were asked which of the two images they viewed at encoding.

• A-A’ Condition: The target was paired with a corresponding lure

• A-B’ Condition: The target was paired with a non-corresponding lure

Figure 1

Encoding Retrieval

288 pictures, 2000 ms

192 trials (96/condition)

Results

Event-Related Potentials (ERPs)

• EEG was recorded with a sampling rate of 512 Hz (BioSemi Active 2) from 64 active AgAgCl scalp electrodes and two vertical and two horizontal electrooculogram (EOG) channels re-referenced offline to a linked mastoid configuration using Brain Electrical Source Analysis (BESA) software (MEGIS Software GmbH, Gräfelfing, Germany). Ocular artifacts were corrected applying the Ille, Berg, & Scherg (2002) algorithm Trials were hand-edited to remove movement related artifact Data were high and low pass filtered at 0.1 Hz and 30 Hz, respectively. A minimum of 10 trials were required per condition. Trials were epoched with a 100 ms baseline and continued during stimulus presentation for 1500 ms The following analyses were conducted on baseline-corrected mean amplitudes 500-700 ms poststimulus onset

Behavioral Performance (Figure 2)

• Consistent with previous research, participants performed better on the A-A’ condition than the A-B’ condition, t(17) = 3.525, p = .003. ERP Data

• A 2 Stimulus (A, B) x 2 Accuracy (Incorrect, Correct) x 3 Coronal (F, C, P) x 3 Sagittal (Left, Middle, Right) mixedmodel ANOVA on mean amplitudes 500-700 ms

poststimulus onset revealed a marginal stimulus x accuracy interaction, F(1, 17) = 3.302, p = .087.

• On incorrect trials, the mean amplitude elicited to the B stimulus was larger than the A stimulus (Figure 3)

• On correct trials, the mean amplitude elicited to the A stimulus was larger than the B stimulus (Figure 4)

Discussion and Future Directions

• Errors on the A-B’ condition may may occur if encoding of the subsequent lure stimulus (B) superseded the encoding of the target stimulus (A). This explanation was supported by Rollins et al. (2019), which showed that individuals exhibited more fixations to the B stimulus than the A stimulus for subsequently incorrect trials. Similarly, the current study suggests enhanced neural processing of the B stimulus than the A stimulus when they later answered incorrectly. Taken together with our previous research (Rollins et al., 2019), these studies suggest that encoding variability partially accounts for errors observed on the A-B’ test format of the forced-choice MST.

• In contrast, in the A-A’ condition participants are presented with both versions of the stimulus. We had expected either similar neural activity to the A and B stimuli at encoding or enhanced encoding of the A stimulus, which was observed in the present study.

Friedman, D., & Johnson, R. Jr. (2000). Event-related potential (ERP) studies of memory encoding and retrieval: A selective review. Microscopy Research and Technique, 51(1), 6-28. Huffman, D. J., & Stark, C. E. L. (2017). Age-related impairment on a forced-choice version of the mnemonic similarity task. Behavioral Neuroscience, 131(1), 55-67. doi:10.1037/bne0000180

Rollins, L., & Khuu, A, & Lodi, N. (2019). Encoding variability accounts for false recognition of noncorresponding lures on the forced-choice Mnemonic Similarity Task. Learning & Memory, 26(8), 280-283. doi:10.1101/lm.047142.117

Stark, S. M., Kirwan, C. B., & Stark, C. E. L. (2019). Mnemonic Similarity Task: A tool for assessing hippocampal integrity. Trends in Cognitive Sciences, 23(11), 2442-2449. doi:10.1016/j.tics.2019.08.003

Yassa, M. A., & Stark, C. E. L. (2011). Pattern separation in the hippocampus. Trends in Neuroscience, 34(10), 515-525. doi:10.1016/j.tins.2011.06.006

14 A stimulus B stimulus Incorrect Trial Correct Trial References
18 young adults (M = 19 94 ± 1 27 years, 15 females, 3 males)
Task
1)
Mnemonic Similarity
(Figure
Introduction Indoor/Outdoor? Indoor/Outdoor? A-A’ test format A-B’ test format Indoor/Outdoor? 0.0 0.2 0.4 0.6 0.8 1.0 A-A’ A-B’ Proportion Correct Figure 2
Figure 3 Figure 4

Does Accurate Facial Expression Recognition Influence

Dwell Time?

Katie Kozlowski, Kali DeBorde, Ayesha Ferozpuri, Karen Salazar, and Peyton Stites Faculty Sponsor: Dr. Laurie Hunter, Department of Psychology

Abstract

The current study explored whether accuracy of recognition of facial expression of emotion differentiates individual’s eye-tracking patterns, via the eye-tracking metric of dwell time (visit duration). We argue visit duration provides more detailed information for evaluating which features of the face are used more often for processing emotional faces. Visit duration is greater for the middle and lower areas of the faces as compared to the upper and non-core areas of faces, but it is unclear whether this focus leads to greater accuracy (Hunter, Roland, & Ferozpuri, 2019).

Thirty-five undergraduate students from a small liberal arts university in the Mid-Atlantic viewed an 80-slide presentation of faces, taken from CAFE child facial set (LoBue & Thrasher, 2014) and NimStim adult facial set (Tottenham et al., 2009) while measures of eye-tracking were documented using Tobii X3-120. Participants were instructed to label the faces with the appropriate emotion. A median split on accuracy of recognition for each emotion was utilized to divide participants into high accuracy and low accuracy.

Five, one for each emotion (anger, fear, happy, neutral, sad), 2 (Accuracy: high or low) X 2 (age of face) X 4 (AOI) ANOVAs were conducted to assess visit duration. For anger, fear, happy, neutral, and sad, accuracy of recognition did not explain differences in visit duration among the four AOIs. As suggested in previous literature (Hunter, Roland & Ferozpuri 2019), the lower and middle AOI had greater visit durations than upper or non-core AOIs. The non-core area of interest (all areas of the face other than eyebrows, eyes, and nose/mouth) had greater visit duration among individuals with lower accuracy scores compared to individuals with higher accuracy scores. In addition, as with previous studies (Barabanschikov, 2015; Dinkler et al., 2018) the chosen stimuli were ones which had the highest ratings of accuracy from the original validation study, thus stimuli utilized in this study may not be sensitive enough to detect potential differences. Facial expression stimuli with lower accuracy rating (i.e., less intensity) would be a prudent investigation, and would more likely mirror real world interactions.

Kali DeBorde is a senior Psychology major with a minor in Childhood Studies at Christopher Newport University. In the fall, she will be pursuing her Master’s in speech-language pathology at Old Dominion University.

Ayesha Ferozpuri is a Christopher Newport University alumna with a Bachelor of Science in Neuroscience and Psychology. She currently works at Solstice East, a residential treatment center for adolescent girls, as a personal development mentor. In the fall, she will be pursuing her Masters in rehabilitation and mental health counseling at Virginia Commonwealth University.

Karen Salazar is a rising Junior at Christopher Newport University with a Neuroscience major and a double minor in human rights and conflict resolution and psychology.

Katie Kozlowski earned her Bachelor of Science in Psychology at Christopher Newport University. During her time at CNU, she was a research assistant in the Facial Processing and Recognition Lab and plans to work in the data analysis field.

Peyton Stites earned her Bachelor of Science in Psychology at Christopher Newport University and took part in Emotion/Recognition research. She plans to continue her education and obtain her Master in Occupational Therapy.

This poster was accepted for presentation at the 66th Annual Meeting of the Southeastern Psychological Association.

Does Accurate Facial Expression Recognition Influence Dwell Time?

Abstract

The current study explored eye-tracking patterns and examined whether accuracy of recognition differentiated how facial expressions of emotion are processed. Specifically, we asked whether accurate recognizers focused more on the critical areas of interest. Our findings indicated no difference between the high and low accuracy groups when processing emotions. Both groups focused on the middle and lower areas of the face most often, support previous literature, thus highlighting on the importance of eyes and mouth when processing emotions.

Methodology

● The participants were instructed to label the faces with the appropriate emotion.

● A median split on accuracy of recognition for each emotion was utilized to divide participants into high accuracy and low accuracy.

Findings

Results

Five 2x2x4 mixed model ANOVAs (2 Accuracy of recognition, high versus low); 2 ages: adult and children & 4 AOIs: lower, middle, noncore, and upper) were conducted for anger, fear, happy, neutral, and sad.

● Of importance to the current study, no interactions among AOIs and accuracy were obtained for any of the emotions.

o F(3, 387) = 0.467, p>0.05.

● Hunter, Roland, and Ferozpuri (2019) found that visit duration is greater for the middle and lower areas of the face in comparison to upper and non-core areas of the face.

● The mouth (low AOI) is necessary for the recognition of happiness and the eye (middle AOI)/brow (upper AOI) is necessary for the recognition of sadness (Beaudry et al., 2014).

● The lower and middle AOI have greater visit duration compared to upper or non-core AOI (Hunter, Roland, and Ferozpuri, 2019).

Importance of the Research Participants

● 138 undergraduate students from a small liberal arts university in the Mid-Atlantic.

● An 80-slide presentation of faces was taken from CAFE child facial set (LoBue & Thrasher, 2014) and NimStim adult facial set (Tottenham et al., 2009) while measures of eye-tracking were documented using Tobii X3-120.

(Tottenham et al., 2009)

References

Barabanschikov, V.A. (2015). Gaze dynamics in the recognition of facial expressions of emotion. Perception, 44(8-9), 1007-1019. doi: 10.1177/0301006615594942.

Beaudry, O., Roy-Charland, A., Perron, M., Cormier, I., Tapp, R. (2014). Featural processing in recognition of emotion facial expressions. Cognition and Emotion, 28(3), 416-432. Hunter, L.S., Roland, L. & Ferozpuri, A. (2019). Emotional expression processing and depressive symptomatology: Eye-tracking reveals differential importance of lower and middle facial areas of interest. Manuscript under revision, Depression Research and Treatment.

LoBue, V., & Thrasher, C. (2015). The child affective facial expression CAFE) set: Validity and reliability from untrained adults. Frontiers in Psychology, 5 1-8.

Tottenham, N., Tanaka, J. W., Leon, A. C., McCarry, T., Nurse, M., Hare, T. A., & Nelson, C. (2009). The NimStim set of facial expressions: Judgements from untrained research participants. psychiatry Research, 168(3), 242-249. doi: 10.1016/j.psychres.2008.05.006

o F(3,387) = 1.470, p>0.05.

o F(3, 387) = 0.795, p>0.05.

o F(3, 387) = 0.223, p>0.05.

o F(3, 387) = 0.257, p>0.05.

Interpretation

● The ability to accurately recognize emotion did not have an effect on a participant's ability to process faces

● The lower and middle AOI have greater visit duration in comparison to the upper and non-core AOI, for each of the five emotions

● For this study, facial emotion stimuli were chosen specifically for their ease of recognizability.

○ Stimuli with lower recognizability scores, arguably more difficult to process, may provide an ability to detect differences in processing for various emotions.

16
Face Processing Research

Developmental Improvements on the Forced-Choice Mnemonic Similarity Task in Childhood

Nafessa Lodi

Faculty Sponsor: Dr. Leslie Rollins, Department of Psychology

Abstract

The Mnemonic Similarity Task (MST) assesses memory discrimination. Developmental research using modified study-test versions of the MST suggests age-related improvements in mnemonic discrimination occur in childhood (Ngo, Newcombe & Olsen, 2017; Rollins & Cloude, 2018). Huffman and Stark (2017) employed a forced-choice version of the MST with young and older adults. During retrieval, a target (previously viewed item) was either paired with a novel, unrelated item (A-X), a corresponding lure (A-A′), or an unrelated lure (A-B′). Performance was highest on A-X, intermediate on A-A′, and poorest on A-B′. Relative to younger adults, older adults demonstrated impairment on A-A′ but not A-B′ or A-A′. The forced-choice MST removes differences in task performance that could be attributable to age-related differences in response criteria. Our goal is to examine the development of mnemonic discrimination in childhood using the forced-choice MST. In our study, 4- and 6-year-olds, and young adults complete the forced-choice MST. Participants encode 100 pictures from the Stark Laboratory database. Retrieval consists of 75 trials divided between the A-X, A-A′, and A-B′ formats. Data is reported

from 15 young adults, 13 4-year-olds, and 15 6-year-olds. A 3 Test Format x 3 Age Group mixed-model ANOVA analyzed the proportion of correct responses to assess age-related differences of mnemonic discrimination. Consistent with research (Huffman & Stark, 2017; Rollins, Khuu, & Lodi, 2019), individuals performed best on A-X, intermediate on A-A′, and the worst on A-B′, F(2, 80) = 77.79, p < .01. The main effect of age group was significant, F(2, 40) = 39.12, p < .01. Young adults outperformed 6-year-olds; 6-year-olds outperformed 4-year-olds. Test format and age group influenced mnemonic discrimination, F(4, 80) = 3.311, p = .02. On the A-X format, 6-year-olds and young adults performed better than 4-year-olds. On the A-A′ format, young adults performed better than 4- and 6-year-olds. On the A-B′ test format, all age groups were significantly different from one another; young adults outperformed 6-year-olds; 6-year-olds outperformed 4-year-olds. These findings suggest age-related improvements in mnemonic discrimination during childhood and that the processes that underlie the changes may be partially dissociable from those that decline in aging.

Nafeesa Lodi is majoring in Neuroscience and minoring in Leadership Studies. She started working with Dr. Rollins during her freshman year and participated in the 2019 Summer Scholars Program. Nafeesa co-authored a paper that was published in Learning and Memory in 2019, titled, “Encoding variability accounts for false recognition of noncorresponding lures on the forced-choice Mnemonic Similarity Task”.

This poster was accepted for presentation at the 66th Annual Meeting of the Southeastern Psychological Association.

Developmental Improvements on the Forced-Choice Mnemonic Similarity Task in Childhood

Nafeesa Lodi

Faculty Sponsor: Dr. Leslie Rollins

Christopher Newport University

Introduction

• Development of mnemonic discrimination

• Forced-choice assessment of mnemonic discrimination

A’), A’ B’

• Goal of the present study:

Results

Participants

• Mnemonic Similarity Task (Figure 1)

• A′ test B′ test

F

• F

• F B’ test format.

Discussion and Future Directions

• A’), and the worst when they were paired with non B’) in both

• A’ and A B’ test formats than

Methods

Acknowledgements

References

• A’ Condition: One image viewed at encoding (the target) and another was a

• B’ Condition: One image viewed at encoding (the target) and another was a non

A’ B’ • A’ B’ Figure

1

Behavioral Neuroscience 131

NeuroImage, 94

Developmental Science

Learning & Memory 26

Learning & Memory

Neuropsychologia 51 Neurobiology of Aging

Trends in Neuroscience, 34

18
14
• A’ B’
Figure 1
• Hypotheses: •
Encoding Retrieval

The Threshold Hypothesis: A Statistical Analysis

Faculty Sponsor: Dr. Gayle Dow, Department of Psychology

Abstract

Theoretical associations between intelligence and creativity have been a focus of educational research for decades. Termed the “threshold hypothesis”, researchers have concluded that a minimum level of intelligence is required to yield creative products. However, conflicting research has concluded that while creativity and intelligence are positively correlated this association dissipates once IQ exceeds 120. Perhaps this disagreement stems from the method of creativity assessment. In the current study, participants completed an IQ test and two creativity tests assessing convergent and

divergent thinking. Both linear and quadratic regressions were conducted between IQ and these two forms of creativity. While there were no linear or quadratic trends found between IQ and convergent thinking, a significant quadratic trend was demonstrated on IQ and divergent thinking. This trend was not present once IQ exceeded 120, thus supporting the threshold hypothesis and a truncated range. Implications and limitations will be discussed.

Mara McFadden is a Junior Psychology major at Christopher Newport University from Richmond Virginia. Mara is very involved on and off campus at CNU, as she is a member of Alpha Phi, a member of the a cappella group The Newport Pearls, and has been working in Dr. Dow’s research lab for the past academic year. Off campus, Mara is a database management intern at Fear 2 Freedom, a non-profit organization founded by Rosemary Trible. Mara’s research in the Psychology department has been focused on a more statistical approach as she hopes to pursue a career in statistics and data analysis.

The Threshold Hypothesis: A Statistical Analysis

Psychology Department at Christopher Newport University

Abstract

Theoretical associations between intelligence and creativity have been a focus of educational research for decades. Termed the “threshold hypothesis,” researchers have concluded that a minimum level of intelligence is required to yield creative products. However, conflicting research has concluded that while creativity and intelligence are positively correlated, this association dissipates once IQ exceeds 120. Perhaps this disagreement stems from the ability level of those studied and also the method of the creativity assessment. In the current study, over 100 gifted students completed an IQ test and two creativity tests assessing convergent and divergent thinking. Both linear and quadratic regressions were conducted between IQ and these two forms of creativity. While there were no linear or quadratic trends found between IQ and convergent thinking, a significant quadratic trend was demonstrated on IQ and divergent thinking. This trend was not present once IQ exceeded 120, thus supporting the threshold hypothesis and a truncated range. Implications and limitations will be discussed.

Introduction

Creativity and intelligence are typically broadly defined; intelligence is witnessed through the acquisition and application of knowledge and skills while creativity is presented by how that knowledge and skill are adapted in novel manners to a specific environment (Sternberg, 2000). Researchers have suggested the relationship between creativity and intelligence is non linear and perhaps is positively correlated but terminates once an individual reaches an IQ of around 120 (Welter, Jaarsveld, Leeuwen, & Lachmann, 2016). The purpose of the present research is to determine if this Threshold Hypothesis exists. This current study differs from previous research on the threshold hypothesis in two forms:

1. The study focused on gifted students

2. The study analyzed two different forms of creativity; divergent and convergent.

Purpose

The purpose of this study was to further investigate the relationships between intelligence and creativity in the population of gifted students by using both linear and quadratic regressions. Further, it aims to explore the Threshold Hypothesis, a topic that does not have one consensus amongst the psychology community.

Methods

Participants: 102 students enrolled in the Governor's School of the Gifted participated in this study.

Measures: Three measures; Remote Association Test (RAT) (convergent) creativity test, Fluency (divergent) creativity test, and IQ test. Procedure: Participants provided informed consent and engaged in a variety of activities and tests to measure different forms of creativity and intelligence.

Results

RAT and IQ were not linearly related R2 =.018, F(1,101)=1.854, p=.176 and there was no quadratic trend R2=.042, F(2,100) = 2.167, p=.120. There was a quadratic trend between Fluency and IQ R2 =.062, F(2,100)= 3.29, p=.041.

Conclusion/Future Studies

The results demonstrate that there is a significant relationship between divergent creativity, as measured by the fluency test, and intelligence, as measured by IQ. In line with the Threshold Hypothesis, we found that beyond an IQ of 120, there was no significant relationship between intelligence and divergent creativity. Thus high rates of creativity are not restricted to high IQ individuals. This study’s results did not reveal a relationship between convergent creativity, measured by the RAT, and intelligence.

Based on the results from this study, future studies are warranted to investigate the effectiveness of different measures of creativity (e.g., problem solving). Furthermore a more diverse array of participants (e.g. beyond just gifted students) will aid in generalizing to multiple fields in education to ensure that creativity production and talent identification is not restricted to only those who qualify for gifted education.

Sources

Sternberg, R., & O'Hara, L. (2000). Intelligence and Creativity. In R. Sternberg (Ed.), Handbook of Intelligence (pp. 611-630). Cambridge: Cambridge University Press. doi:10.1017/CBO9780511807947.028

Welter, M., Jaarsveld S., van Leeuwen C., & Lachmann T. (2016). Intelligence and Creativity: Over the Threshold Together? Creativity Research Journal, 28(2), 212-218, doi 10.1080/10400419.2016.1162564 Guilford, J. P. (1967). The nature of human intelligence. New York: McGraw-Hill.

Jauk E., Benedek, M., Dunst, B., & Neubauer, A. C. (2013). The relationship between intelligence and creativity: New support for the threshold hypothesis by means of empirical breakpoint detection. Intelligence Journal, 41, 212-221. doi 10.1016/J.INTELL.2013.03.003

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Maternal Subpopulation Variances In Vaginal And Cesarean Section Delivery Methods Predicts Excess Infant Mortality Of Blacks

In United States: Linked Birth/Infant Death Records, 2007-2016

Abstract

Background: Racial disparities have been observed in infant mortality (IM) but the risk factors are not fully understood. Available literature identified risk factors of both the mother (such as education, income, social stress and racial discrimination) and infant (such as birth weight and sex). Specifically, Black/African Americans (B/AA) are 3 times more likely to die compared to whites. To improve intervention mapping in reduced the excess IM experienced by B/AA, studies should focus on the effects of maternal factors and labor/delivery procedures. Objectives: The current study aimed to assess the exposure function of labor and delivery procedures as potential explanations for excess Black/AA IM relative to white IM in the United States. Methods: Data was collected from the United States Linked Birth/Infant Death records, 2007-2016. A cross-sectional ecological design was used to determine the dependence of labor and delivery methods with infant mortality, factors associated with infant mortality, and the period of prevalence. Analysis on chi-squared statistic, incidence rate ratio and period percent change was computed using STATA 14.0. Results: Of the 40,445,070

births, the cumulative mortality was 249,135 (1.16 per 1000). Racial differences were observed highest among B/AA (11.41 per 1000) and intermediate among whites (5.19 per 1000). The cumulative incidence rate difference comparing vaginal deliveries to cesarean deliveries was 1.74 per 1000. Compared to c-section, there was a 31% decreased risk of infant mortality among mothers with vaginal delivery, rate ratio (RR) = 0.69, 95% CI 0.64-0.74. Black/AA mothers with vaginal delivery had a 6% decreased risk of IM compared to C-section, RR = 0.94, 95%CI 0.92-0.95, while whites with vaginal delivery had a 38% decrease risk of IM relative to C-section, RR= 0.68, 95%CI 0.67-0.69, p<0.001. Conclusion: IM varied by race, which is explained in part by labor and delivery procedures, suggesting reliable intrapartum assessment of Black/AA mothers during labor. Overall, the findings from this research would further support the racial disparities that exist between labor and delivery methods and infant mortality outcomes.

Leah O’Neill recently graduated from Christopher Newport University with a Bachelor of Science in Cellular, Molecular and Physiological Biology and a Minor in Leadership Studies; she was involved in CNU’s Presidential Leadership Program, Pre-Medical Scholars Program, and Alpha Chi Sigma. Her research on the effect of vaginal and cesareansection deliveries on infant mortality rates between Black and White women within the United States was a result of her work during her 2019 summer internship with Nemours Children’s Hospital in Wilmington, Delaware. Leah O’Neill was accepted into the 2020 Graduate Program of Biological Sciences at the University of Delaware and will be furthering her education with the field of Molecular Biology and Genetics.

Maternal Subpopulation Variances in Vaginal and Cesarean Section Delivery Methods Predicts

Excess Infant Mortality of Blacks in United States: Linked Birth/Infant Death Records, 2007-2016

O’Neill, L. 1,2 , Enwere, M. 1,3 , Pelaez, L.1, Dabney K. Dr. 1, Holmes, L. Jr. 1,4 Nemours Healthcare System for Children, Wilmington, DE 198031, Christopher Newport University, Newport News, Virginia2, Walden University, Minneapolis, Minnesota3, University of Delaware, Newark, Delaware, Biological Sciences Department4

INTRODUCTION

Background

• Racial disparities have been observed in infant mortality but the risk factors are not fully understood.

• In 2017, there were more vaginal deliveries (n = 2,621,010) relative to cesarean deliveries (n = 1,232,339) with the rates of vaginal deliveries declining and cesarean section delivery rates increasing.1

• In comparison to vaginal deliveries (VD), cesarean deliveries (CD) come with the increased risk of maternal and fetal complications.2

• Infant mortality is the death of an infant before their first birthday and is expressed as the rate of deaths per 1,000 live births.3

• In 2015, the Center for Disease Control and Prevention (CDC) reported that sudden unexpected infant death (SUID) represented 15% of all infant deaths in the United States (US).3

• There are 3 reported types of SUID cases: sudden infant death syndrome (SIDS), unknown cases, and accidental suffocation/strangulation in bed.1

• Available literature identified risk factors of both the mother (such as education, income, social stress and racial discrimination) and infant (such as birth weight and sex).

• Non-Hispanic black women have a higher rate of cesarean delivery (36%) compared to non-Hispanic white women (30.9%).4

• In 2017, the CDC reported that infant mortality rates were higher among non-Hispanic black women (11.4 deaths per 1,000 live births) relative to non-Hispanic white women (4.9 deaths per 1,000 live births).3

• The disproportion of infant mortality rates between black and white women within the US has more than doubled in the past decade.5

Study Aims

• The current study aimed to assess the exposure function of labor and delivery procedures as potential explanations for excess black/African American (B/AA) infant mortality relative to white infant mortality in the US.

METHODS

• After an institutional review board (IRB) approval we conducted a study to assess the relationship between infant mortality and method of delivery depending on their racial heterogeneity.

Study Design

• A cross sectional ecologic non-experimental design was used to determine the dependence of labor and delivery methods with infant mortality, factors associated with infant mortality, and the period of prevalence.

Data Source

• Data from linked birth/infant death records from 2007 to 2016 were acquired from the National Health Statistics Center (NHSC) of the CDC.

Study Variables

• Variables assessed were maternal bridged race, maternal education, infant gender, infant year of death, and infant birth weight.

Study Analysis

• Chi squared statistics, incidence rate ratio and descriptive statistics were performed utilizing STATA 14.0.

• A standardized formula was used in computation of the period prevalence to determine whether or not the method of delivery, with respect to mortality, remained stable or changed.

RESULTS

STUDY LIMITATIONS

• There was the potential for misclassification of the exposure variable (mortality) and unmeasured confounding

• Other limitations include misclassification of infant race and too small of a sample size in regard to certain racial groups, such as American Indian/Alaskan Native and Asian/Pacific Islander

CONCLUSION

• The cumulative infant mortality rate during 2007-2016 was 6.16 per 1,000.

• Rates varied by the method of delivery; infant mortality related to c-section (8.49 per 1,000) was higher relative to vaginal delivery (6.75 per 1,000), indicating a 1.74 per 1,000 infant mortality rate difference.

• Racial differences were observed highest among black/African American infants (11.41 per 1,000), intermediate among American Indian/Alaskan Native (8.32 per 1,000) and whites (5.19 per 1,000), and lowest among Asian/Pacific Islander (4.24 per 1,000).

• There was a 6% decreased risk in infant mortality among B/AA mothers with vaginal delivery.

• In comparison, infant mortality following vaginal delivery among white mothers were associated with a 32% decreased risk, incidence rate ratio (IRR) = 0.68, 95% confidence interval (CI) 0.67-0.69, p<0.001.

• Infant mortality varied by mother’s education regardless of the method of delivery.

• Among B/AA, either vaginal (9.8 per 1,000) or c-section (13.0 per 1,000) infant mortality was highest among mothers with less than a high school education, while mothers with a post college degree experienced lower vaginal (7.46 per 1,000) and cesarean (6.45 per 1,000) infant mortality rates.

• White mothers with less than a high school education experienced lower vaginal (4.19 per 1,000) or cesarean section (10.93 per 1,000) infant mortality rates. While mothers with a post college degree were associated with the lowest rate of vaginal (2.5 per 1,000) delivery, and cesarean section (3.9 per 1,000)

• Regardless of the method of delivery, race or education, the risk of dying as an infant was higher for males compared to their female counterpart.

• Overall, the findings from this research would further support the racial disparities that exist between labor and delivery methods and infant mortality outcomes.

REFERENCES

1. “Births - Method of Delivery.” Centers for Disease Control and Prevention, U.S. Department of Health & Human Services, 20 Jan. 2017, www.cdc.gov/nchs/fastats/delivery.htm

2. “Complications of Cesarean Deliveries.” Medscape, WebMD, www.medscape.org/viewarticle/512946_4

3. “Reproductive Health.” Centers for Disease Control and Prevention, U.S. Department of Health & Human Services, 27 Mar. 2019, www.cdc.gov/reproductivehealth/maternalinfanthealth/infantmortality.htm

4. Martin, J.A., M.P.H., Hamilton, B.E., Ph.D., Osterman M.J.K., M.H.S., Driscoll, A.K., Ph.D., Drake, P., M.S. “Births: Final Data for 2017.” National Vital Statistics Reports, vol. 67, no. 8, 7 Nov. 2018.

5. Matthews, T. J., MacDorman, M.F., PhD, Thomas, M.E., PhD. “Infant Mortality Statistics from the 1999 Period: Linked Birth/Infant Death Data Set.” National Vital Statistics Reports, vol. 64, no. 9, 6 Aug. 2015, doi:10.1037/e558952006-001.

22
VD 7.70 CD 10.68 VD 3.74 CD 4.61 VD 11.60 CD 12.63 VD 4.70 CD 6.77 VD 7.05 CD 10.70 VD 4.22 CD 4.97 VD 10.64 CD 11.13 VD 4.32 CD 6.44 VD -8.3 CD 0.22 VD -11.34 CD -7.24 VD -8.28 CD -11.83 VD -8 CD -5 -15.00 -10.00 -5.00 0.00 5.00 10.00 15.00 AI/AN A/PI B/AA W Y-2007-2011 Y-2012-2016 Percent Change
Variable AI/AN1 n2(%)3 A/PI4 n2(%)3 B/AA5 n2(%)3 W6 n2(%)3 x2 7 (df8) p9 Method of Delivery - - - - 40,000 (4) <0.001 Vaginal 2,459 (0.7) 7,073 (0.4) 46,709 (1.1) 94,737 (0.5) -Cesarean 1,408 (1.10 4,179 (0.5) 26,960 (1.2) 64,890 (0.7) -Abbreviations & Notes: American Indian/Alaskan Native (AI/AN), sample size (n), prevalence of death (%), 4Asian/Pacific Islander (A/PI), Black/African American (B/AA), White (W), chi squared (x), degrees of freedom (df), p-value (p)
Table 1. Effect of method of delivery characteristics on infant mortality by racial groups, 2007-2016. Figure 1. Trends and Period Percent Change in Infant Mortality by Method of Labor and Delivery, US Linked Birth/Infant Death Records, 2007-2016
Variable Incidence Rate Ratio 95% CI1 p2 Race AI/AN3 0.69 0.64 – 0.74 <0.001 A/PI4 0.83 0.80 – 0.86 <0.001 B/AA5 0.94 0.92 – 0.95 <0.001 W6 0.68 0.67 – 0.69 <0.001 Abbreviations & Notes: Confidence Interval (CI), p-value (p), American Indian/Alaskan Native (AI/AN). 4Asian/Pacific Islander (A/PI), Black/African American (B/AA), White (W)
Table 2. Incidence rate ratio characteristics on infant mortality risks by racial groups from 2007 – 2016.

Detection of bacterial contamination by nitroreductase

Faculty Sponsor: Dr. Todd

of Molecular Biology and Chemistry

Abstract

Nitroreductase is a bacterial enzyme not present in mammalian cells. In previous research, we engineered a nitroreductase to release dyes, indicators and drugs in a cellspecific manner. Furthermore, we are extending this work into the area of bacterial detection. Because nitroreductase is absent in mammalian cells, this is a unique activity to identify contamination in clinical samples. With further development, we aim to apply this method to the medical field in terms of detecting bacteria in bodily fluids.

We find that E. coli nitroreductase, as natively expressed in the clinically-isolated E. coli K-12 strain, reacts with masked bis(2-nitro-N-methyl imidazolyl)-Oregon Green (NMOG) to release the fluorophore Oregon Green. This method successfully detects E. coli K-12 strain using a fluorescence plate reader. Additionally, qualitative analysis using blue light supports our findings. Limits of detection have also been analyzed for this process.

Ryan Saal is a second year student at Christopher Newport University and is majoring in Biochemistry with a minor in Leadership Studies. He is a Presidential Scholar while also being a member of both the Honors College and the President’s Leadership Program. On campus, Ryan is involved in CNU Residence Life as a Resident’s Assistant and the Center for Academic Success as an Organic Chemistry tutor. In his free time, he enjoys undergraduate research and singing in an Acapella group called University Sounds. He hopes to one day attend medical school and become a physician.

Zoe Stauffer is a junior at Christopher Newport University. She is majoring in Cellular, Molecular, and Physiological Biology with minors in Leadership and Spanish. She is a member of both the Presidential Leadership program and Pre-Med Scholars program on campus. Zoe is also a captain on the track and field team and competes

in the heptathlon. In her free time, she enjoys anything outdoors such as skiing, scuba diving, and hiking. Her career aspiration is to be a physician.

Shreya Ganta is a second year student at Christopher Newport University and is majoring in Cellular, Molecular and Physiological biology with a minor in Leadership Studies. She is a Presidential and Riverside Medical Group Scholar while also being a member of both the Honors College and President’s Leadership Program. Shreya is an active brother of Alpha Phi Omega and is also the Social Media Chair for the bone marrow registry awareness club, Be The Match. She is a nationally ranked Division III golfer. In her free time, Shreya enjoys undergraduate research, volunteering, and going to the beach. She hopes to attend medical school and become a physician.

Abstract

Detection of bacterial contamination by nitroreductase

Nitroreductase is a bacterial enzyme not present in mammalian cells. In previous research, we engineered a nitroreductase to release dyes, indicators and drugs in a cellspecific manner. We are extending this work into the area of bacterial detection. Because nitroreductase is absent in mammalian cells, this is a unique activity to identify contamination in clinical samples. With further development, we aim to apply this method to the medical field in terms of detecting bacteria in bodily fluids. We find that E. coli nitroreductase, as natively expressed in the clinically-isolated E. coli K-12 strain, reacts with masked bis(2-nitro-N-methyl imidazolyl)-Oregon Green (NMOG) to release the fluorophore Oregon Green. This method successfully detects E. coli K-12 strain using a fluorescence plate reader. Additionally, qualitative analysis using blue light supports our findings. We are in the process of analyzing limits of detection for this process.

Background

Bacteria make up the vast microbial world that carry out tasks ranging from producing oxygen to causing disease. Bacterial contamination is a recurrent problem in both clinical and laboratory settings. Thus, there is a need for an efficient and adequate detection process. We recently showed that transfected nitroreductase, an enzyme natively found in bacteria but not mammalian cells, could be used as a unique enzymatic activity in mammalian culture to deliver various small molecules (Gruber 2018). Here, we examine whether a nitroreductase activated masked fluorophore can be used to detect bacteria.

Bis(2-nitro-N-methyl imidazolyl)-Oregon Green (NMOG) is non-fluorescent, and nitroreductase converts it to the fluorescent dye Oregon Green.

Standard Fluorescent Analysis

A standard linear progression was calculated to show the relationship between OG concentration and relative fluorescent units. The data was used to determine the amount of NMOG required for bacterial analysis. RFU of bacterial assays using 5 µM NMOG did not exceed 2000. More NMOG may be required for greater detection.

NMOG Interacts with Nitroreductase in

Bacteria

Red and Blue: 5 µM NMOG, 100 mM HEPES 100 µM NADH Green and Purple : 5 µM NMOG, 100 mM HEPES 100 µM NADH, 10 µL K-12 sample

Qualitative Analysis with Blue Light

We find that E. coli K-12 samples can be distinguished from samples without bacteria after addition of NMOG using both quantitative and qualitative methods. Analysis reveals that in the absence of bacteria, the RFU is negligible, seen as the red and blue lines. Upon the addition of bacteria, a robust signal is emitted. After three hours, the RFU reaches 1200, seen as the purple and green lines. Qualitative analysis was carried out using excitatory blue light. An amber emission filter revealed the green fluorescence in wells that correlate with the purple and green lines. No fluorescence is seen in wells that correlate with the red and blue lines.

Limits of Detection

Red: 5 µM NMOG, 100 mM HEPES, 1 µM NADH, 10 µL k-12 Blue: 5 µM NMOG, 100 mM HEPES, 1 µM NADH, 1/10th k-12 Green: 5 µM NMOG, 100 mM HEPES, 1 µM NADH, 1/100th k12

An analysis of nitroreductase limits of detection reveals that the method efficiently detects 10 µL k-12 sample, with an RFU of 3000. The solutions were diluted. The 1/10th dilution was detected, though the RFU did not surpass 250. The RFU for dilutions of 1/100th the sample or less was not sufficiently detected. The normal 10 µL k-12 sample (red line) plateaus after 2 hours. This data suggests that the NMOG or NADH (reaction catalyst) was depleted. Optical density was used to estimate the amount of k-12 bacterial cells in the sample as a benchmark. The next step would be getting a more accurate quantification of bacterial cells for analysis.

Summary

• The nitroreductase activated masked fluorophore was successfully used in the detection of k-12 bacteria

• Quantitative analysis showed that samples containing the bacteria emitted an RFU around 1200 after three hours

• The detection technique was examined qualitatively using blue light which adequately distinguished wells with bacteria from wells without bacteria

• Limits of detection for the technique are underway

References

Gruber, T. D., Krishnamurthy, C., Grimm, J. B., Tadross, M. R., Wysocki, L. M., Gartner, Z. J., Lavis, L. D. ACS Chemical Biology 13(10), 2888-2896 (2018).

Shiferaw, T., Beyene, G., Kassa, T., Sewunet, T. Annals of Clinical Microbiology and Antimicrobials 12(39), (2013).

Acknowledgments

This work was supported by startup funds to TDG from CNU and a 2018 Small Project Research Grant from the Virginia Academy of Sciences.

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Time RFU Time RFU

Intramolecular Difunctionalizations of Tethered Aminoalkenes with Hypervalent Iodine

Faculty Sponsor: Dr. Dmitry Liskin, Department of Molecular Biology and Chemistry

Abstract

The nitration, sulfamination, and chlorination of aminoalkenes are commonly used reactions that yield differently substituted nitrogen heterocycles. Nitrogen heterocycles, which include substituted pyrrolidines and piperidines, are heavily present in the pharmaceutical industry as the base of antibiotics, antifungals, and other medications. Therefore, there is a big demand for a cheaper, greener method to synthesize them. In the past, additions to aminoalkenes have been carried out with the use of metals as catalysts.1,2 Oxidative addition, reductive elimination, and ligand coupling are usually catalyzed by transition metals due to their ability to change oxidation state. They can lend electrons or withdraw electrons from the reagent, depending on the nature of

the mechanism. However, the byproducts of such reactions are often harmful for the environment and toxic. Therefore, there is a need for a greener method to catalyze these widely used methods. In the past years, hypervalent iodine has emerged as a versatile oxidant in organic chemistry. Its structure and reactivity are similar to those of transition metals; however, iodine is cheaper and more environmentally friendly. Here we report the use of hypervalent iodine as the oxidant in the sulfamination, chlorination, and nitration of tethered aminoalkenes to yield pyrrolidines and piperidines, which have widely been utilized as important precursors for the synthesis of pharmaceuticals and biological active compounds.

Sara Safford graduated from Christopher Newport University in May 2020 with a Bachelor of Science in Biochemistry. She has been working with Dr. Dmitry Liskin since January 2019 in the MBCH department after she enjoyed learning about organic chemistry. She started shadowing Connor Beveridge, who was working for Dr. Liskin at the time, and she quickly became in charge of her own research. She has presented at the Southeastern Regional Meeting (SERMACS) in October 2019, where she discovered the importance of communication in science.

This poster was accepted for presentation at the 2020 National Meeting of the American Chemical Society.

Intramolecular Difunctionalizations of Tethered Aminoalkenes with Hypervalent Iodine

Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA

Abstract

The pharmaceutical industry relies heavily on nitrogen heterocycles, which include substituted pyrrolidines and piperidines, and has a constant demand for economical and facile method In recent decades, great advances have been made towards synthesis of these compounds with the use of hypervalent iodine, an economical and environment-friendly oxidant Here we report a generic method of cyclizing tethered aminoalkenes in the presence of a strong Bronsted acid and hypervalent iodine

The conjugate base gets incorporated in an endo fashion HCl, H2SO4, and HNO3 have been tested on a range of substrates to give 5-, 6-, and 7-membered rings in very good to excellent yields. The reaction proceeds at room temperature and is air and water tolerant

General reaction

Sulfamination (endo cyclization)

2

3

4

5

RS/SR

RR/SS

Chloroamination (exo cyclization)

Diamination? (endo cyclization)

Figure 4.

References

Y RSC Advances 2013 , 3 (14 ), 4523

(5) Lovick H. M.; Michael, F. E. J. Am. Chem. Soc. 2010 132 , 1249 -1251

Acknowledgements

Sara Safford, Connor Beveridge, and Dmitry Liskin would like to thank the Department of Molecular Biology and Chemistry, the Dean of NBS, and the Office of the Provost for financial support

We would also like to thank Dr Edward J Valente (University of Portland) for solving X-Ray structures and Jeffrey Carney at CNU

26
Entry HNO3, M 1a, NMR yield 1 1M 48% 2 6M 88% 3 8M 99% 4 11.6M 97%
Entry PhI, equivalent NMR yield
1 4.80 99%
2.45 98%
2.00 99%
1.50 98%
1.00 98%
1HNMR of HNO3 product
(1 ) Liskin D V.; Sibbald , P A .; Rosewall C F.; Michael, F E J Org Chem 2010 , 42 (3 ) (2 ) Yoshimura, A .; Zhdankin V V Chemical Reviews 2016 116 (5 ), 3328 – 3435 (3 ) Kloeckner, U .; Nachtsheim , B J RSC Advances 2015 , 46 (6 ) (4 ) Li, L .; Li, Z .; Huang, D .; Wang, H .; Shi,
Table 1. HNO3 molarity optimization Table 2. PhI equivalent optimization (8M HNO3) Scheme 3. Endo cyclization of aminoalkene Scheme 1. Chloroamination of aminoalkene Scheme 2. Sulfamination of aminoalkene Figure 1. X-Ray structure of sulfamination product Figure 2. Substrate optimization Figure 3. Substrate optimization

The degradation of polyethylene terephthalate by Ideonella sakaiensis under varied conditions

Caroline Tsui

Faculty Sponsor: Dr. Todd Gruber, Department of Molecular Biology and Chemistry

Abstract

Ideonella sakaiensis is a bacterium that uses Polyethylene Terephthalate, or PET plastic as its main source of energy. It uses the enzymes PETase and MHETase in tandem to break down PET into its monomers of terephthalic acid and ethylene glycol. The rate at which I. sakaiensis degrades PET is shown using a linear function. I. sakaiensis is also selective with the PET it uses as a food source, and has the ability to use amorphous PET as a food source, but not crystalline. By increasing the surface

area of crystalline PET and powdering it, we test to see if I. sakaiensis can consume crystalline PET in different forms. Past experiments with amorphous PET indicate that a slight increase in weight was observed, which we were able to attribute to the hygroscopic properties of amorphous PET. Crystalline PET was not able to retain water, leading us to question if there is a relationship between hygroscopic PET and the ability for I. sakaiensis to use that plastic as a carbon source.

Caroline Tsui graduated from Christopher Newport University in May 2020 with a degree in Integrative Biology. She began working on this project Freshman year after joining Professor Gruber’s research group. She recently got accepted into Johns Hopkins School of Education and plans to be a teacher in Washington D.C.

The degradation of polyethylene terephthalate by Ideonella sakaiensis under varied

conditions

Purpose of Project

The objective of this project is to investigate the degradation of polyethylene terephthalate (PET) plastic by Ideonella sakaiensis and discover the factors that can influence the rate of PET degradation. The bacteria Ideonella sakaiensis strain 201-F6 releases PETase an enzyme found to break down Polyethylene Terephthalate, or PET plastic.

Objective 1: Measure the rate I. sakaiensis degrades the mass of PET in perfect lab conditions

Objective 2: Determine if I. sakaiensis can eat powdered crystalline PET

Objective 3: Determine if there is a relationship between the hydroscopic attributes of PET and how well I. sakaiensis degrades the plastic.

Background Information

The most widely produced plastic in the world, PET is a polymer composed of ethylene glycol and terephthalic acid. These monomers are derived from raw petroleum and the plastic is prized for its durability and flexibility. But the same reasons that make it so useful to people also make it a huge hazard for the environment. Instead of decomposing, PET breaks down into tinier and tinier pieces called microplastics. These can accumulate and make their way up the food chain in a process known as biomagnification. And while PET plastic is recyclable, it degrades significantly during reheating. Every time it is recycled, the polymer chain grows shorter, and can only be recycled about 2 -3 times before its quality decreases to the point where it can no longer be used. A more common use for PET is downcycling, where lower grade products such as carpets or fabric are made. This form of recycling is known as open loop recycling, and is often seen as postponing disposal as these products are not recyclable.

The bacterium I. sakaiensis was discovered in 2016 in Sakai, Japan and can use PET as its sole carbon and energy source. It hydrolyzes PET by adhering to it and secreting the enzyme PETase, which effectively breaks down the PET into (mono(2-hydroxyethyl) terephthalic acid (MHET). I. sakaiensis then produces MHETase to break MHET down into the PET monomers of ethylene glycol and terephthalic acid. The discovery of an enzyme that can break down PET back into its monomers has huge implications for the future of plastic. If PETase could be engineered in a way to be involved in the recycling process, then there is a possibly of a closing the loop and allowing PET to be repeatedly recycled back into itself.

Research Objective 1: Rate of PET degradation

Determine the rate in which I. sakaiensis degrades a strip of PET plastic. Measurements of plastic weight will be taken every 24 hours.

Rationale: Once a solid function is created for the rate of PET degradation, other experiments can be compared to the original rate function to determine the effectiveness of that factor’s manipulation.

Steps

1. Place strips of PET plastic in 3mls of YSV media with inoculation of I. sakaiensis . Incubated in a shaker at 30 degrees.

2. Weighed every day at the same time.

Research Objective 3: Hygroscopic properties of PET

The amorphous PET that has been found to be edible by I. sakaiensis appears to have hygroscopic properties, meaning it is a material that absorbs water. This led us to question the relationship between hygroscopic plastic and degradation by I. sakaiensis

Rationale: Our laboratory has observed that the PET can grow in mass up to around .0009 g during the first three days before decreasing. This led us to questioning whether the extra weight came from the attachment of I. sakaiensis or whether the amorphous PET was absorbing fluid.

Steps

1. Strips of amorphous PET from blackberry containers or crystalline PET from water bottles were used for each trial

2. Blue contains distilled water, red contains YSV media, yellow contains media and inoculation

3. The PET was left in test tubes and weighed every day. On day three, after weighing, they were left out to dry.

4. They were weighed for two days until plastic returned to original mass

Expected Results

Research Objective 1: Rate of PET degradation by I. sakaiensis

The rate of PET degradation is difficult to capture because the PET gains the first couple days as it becomes waterlogged. As the bacterium multiplies, the mass is reduced accordingly. Results suggests that the plastic is reduced in mass by 0.0012 grams per day under ideal conditions. This can vary depending on how the different variables are altered.

Research Objective 2: Degradation of powdered crystalline PET

While I. sakaiensis cannot degrade crystalline plastic while in large strips, it was anticipated that a reduced surface area could possibly allow the bacteria to consume the crystalline PET.

Results show that I. sakaiensis is a hardy bacteria that can survive with no energy source for weeks at a time. Because powdered crystalline PET can not be weighed, another way to measure Ideonella growth will have to be discovered.

Research Objective 3: Hygroscopic properties of PET associated with degradation

Plastic weighed daily with a final equation of y = -0.0006x + 0.1474

Plastic weighed and 1 ml media replaced daily final equation of y = -0.0009x + 0.1349

Plastic weighted and centrifuged down with media replaced with a final equation of y = -0.0012x + 0.1497

Continued work: Replicate the data to ensure the equation is both precise and accurate

Research Objective 2: Degradation of powdered crystalline PET

Test to see if I. sakaiensis can use powdered crystalline PET as an energy source.

Rationale: I. sakaiensis only degrades amorphous PET, whose polymers are a random molecular jumble. It does not degrade crystalline PET where the molecular chains are locked in place against one another. Because water bottles are mostly composed of crystalline PET due to their stretch blow molding, it is important to see if I. sakaiensis will consume crystalline PET in any form. To test to see if I. sakaiensis can live on crystalline PET, we ran a trial where the surface area was reduced by powdering the PET.

Steps

1. One trial of nine test tubes all with 3ml of YSV media, the first three with a strip of amorphous PET, the second three with powdered crystalline PET, and the last three with nothing

2. After a week, a 20 μl inoculation was taken from each test tube and put in a test tube with 3ml and a strip of amorphous plastic.

Results: All inoculated tubes displayed growth, indicating that I. sakaiensis is a tough bacterium that can survive long periods of time without a food source. Because powdered crystalline PET cannot be weighted, an inoculation was used to determine if I. sakaiensis was alive. A different way to test growth will have to be explored.

Figure 3 displays that the amorphous PET plastic from the blackberry carton does indeed absorb liquid. Both the trials in the distilled water and the YSV media both increased in mass when left in liquid for three days, but went back to the original mass after sitting out and drying for two days. At the same time, the mass of the plastic in the YSV media and inoculation went up the first day and then begun trending downward because I. sakaiensis was degrading the plastic. Figure 4 displays the crystalline water bottle plastic does not absorb water and is also not degradable by the Ideonella

Continued work: Replicate this project by itself, but also with different types and forms of PET plastic (white PET from contact lens solution bottle) to determine if there is a relationship between hygroscopy and I. sakaiensis degradation.

To test the hygroscopic properties, PET plastic is immersed in water, media, and media with inoculation. Mass has been seen to increase for all on the first day, but the trial with media and inoculation was the only one seen to decrease.

Results suggest that the type of PET plastic that is hygroscopic is also degradable by I. sakaiensis . More trials with different forms of PET are needed.

Significance

Objective 1: General rates of plastic degradation are needed for comparison of different growth conditions.

Objective 2: I. sakaiensis exposed to powdered crystalline PET were alive after a week, but so were bacteria that had no plastic at all. Another experiment needs to be devised.

Objective 3: The observed increase in mass during experiments was explained due to the hygroscopic properties amorphous PET.

Acknowledgements

This work was supported by a 2018 Small Project Research Grant from VAS and by funds from Christopher Newport University to Professor Todd Gruber. Ideonella culturing procedures, and alternative ways to measure degradation were performed by Mary Adams, Andrew Chafin, Diamonte Jones, Carson Pittman (HRA), Sam Tyler, Noah Wallace, and Spencer West.

References

1. Austin, Harry P., et al. Proceedings of the National Academy of Sciences, vol. 115, no. 19, 2018, doi:10.1073/pnas.1718804115.

2. Bornscheuer, Uwe T. Science, vol. 351, no. 6278, 2016, pp. 1154–1155., doi:10.1126/science.aaf2853.

3. Tanasupawat, Somboon et al. International Journal of Systematic and Evolutionary Microbiology, vol. 66, no. 8, 2016, pp. 2813–2818., doi:10.1099/ijsem.0.001058.

4. Yoshida, Shosuke, et al. Science, vol. 351, no. 6278, 2016, pp. 1196–1199., doi:10.1126/science.aad6359.

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Figure 1. Ideonella growing on plastic (Yoshida et al., 2016) Figure 2. Figure 3. Figure 4

Investigations

of PETase from Ideonella sakaiensis, a plastic-degrading bacterium

Faculty Sponsor: Dr. Todd Gruber,

of Molecular Biology and Chemistry

Abstract

PETase is an enzyme that is capable of degrading polyethylene terephthalate, the plastic commonly found in plastic water bottles. We have developed assays to measure rates of plastic degradation by this enzyme and have cloned the PETase enzyme into an expression plasmid under an inducible promoter for use in E. coli bacteria. We have expressed the enzyme and can detect activity via a colorimetric assay using p-nitrophenyl acetate (PNPA), a small molecule substrate analog. This assay is straightforward and useful. We have additionally investigated the growth of Ideonella sakaiensis, the bacterium from which PETase was cloned, on different sources of PET. Further, we have developed an assay in which plastic degradation can be monitored spectroscopically, opening the possibility of selecting for improved mutants of the parent organism.

Finally, we have determined that Ideonella likely forms a biofilm on the PET plastic in order to begin its degradation process.

Other strains of bacteria have been found that can deteriorate other types of plastic and it is believed that there are many other forms of bacteria that have evolved the ability to metabolize plastic as a carbon source. We believe an important next step in our research path is developing methodology to screen for other forms of plastic degrading bacteria. Current methodologies are sparse and take on average several months, but we believe with our assays we can develop a methodology that cuts this screening time significantly. Further environmental screening needs to be done to find these bacteria to better understand the enzymes that are used in this process.

Noah Wallace is a member of the class of 2020 at Christopher Newport University. He majored in Biochemistry with minors in Business administration in the Biotechnology and Management Program, Leadership Studies in the President’s Leadership Program, and is a member of the Honors Program. Outside of his studies he has completed over 1000 hours of undergraduate research both during the school year and as a Summer Scholar for two summers. He is a brother of Kappa Delta Rho where he is serving as the Executive Vice President as well as a brother of the National Chemistry Fraternity, Alpha Chi Sigma. Noah is staying at CNU for an additional year to pursue a Master’s Degree in Environmental Science with a thesis topic focused on plastic degrading bacteria.

This poster was accepted for presentation at the 2020 National Meeting of the American Chemical Society.

Investigations

of

PETase from Ideonella sakaiensis, a plastic-degrading bacterium

Abstract

PETase is an enzyme that is capable of degrading polyethylene terephthalate, the plastic commonly found in plastic water bottles We have developed assays to measure rates of plastic degradation by this enzyme and have cloned the PETase enzyme into an expression plasmid under an inducible promoter for use in E coli bacteria We have expressed the enzyme and can detect activity via a colorimetric assay using p-nitrophenyl acetate (PNPA), a small molecule substrate analog This assay is straightforward and useful We have additionally investigated the growth of Ideonella sakaiensis, the bacterium from which PETase was cloned, on different sources of PET Further, we have developed an assay in which plastic degradation can be monitored spectroscopically, opening the possibility of selecting for improved mutants of the parent organism Finally, we have determined that Ideonella likely forms a biofilm on the PET plastic in order to begin its degradation process

Other strains of bacteria have been found that can deteriorate other types of plastic and it is believed that there are many other forms of bacteria that have evolved the ability to metabolize plastic as a carbon source We believe an important next step in our research path is developing methodology to screen for other forms of plastic degrading bacteria Current methodologies are sparse and take on average several months, but we believe with our assays we can develop a methodology that cuts this screening time significantly Further environmental screening needs to be done to find these bacteria to better understand the enzymes that are used in this process Developing this methodology has three proposed steps

Objective 1: Separation of Ideonella from E coli Objective 2 Reisolating of Ideonella from an inoculated soil sample Objective 3: Isolation of a new plastic degrading bacteria

Background Information

Plastic waste is currently one of the worlds biggest problems.

In 2018 more than 400 million tons of plastic was produced, and 40 percent of it was single use plastic that was then thrown away1. Current recycling processes are lackluster and can not accommodate plastic contaminated by food or by the environment, such as ocean plastic. New methods of eliminating plastic waste need to be developed. Current research is already being conducted in our lab and others, using Ideonella sakaiensis a species of bacteria that can metabolize polyethylene terephthalate, a plastic common in plastic packaging. Ideonella is difficult to work with, proving challenging to genetically modify and grow in large quantities. Developing a procedure to better screen for plastic degrading bacteria needs to be performed to observe how other species of the bacteria break down plastic and potentially find a strain of bacteria that is easier to work with.

Previous Work

PET (polyethylene terephthalate) plastic has varying level of crystallinity depending on the plastics intended use and manufacturing process Highly crystalline plastic is impermeable to liquids and gasses and is well suited for containing liquids for applications in the plastic water bottle industry Amorphous plastic has some permeability to gasses and liquids and is common in clamshell containers for produce Ideonella can attach to amorphous plastic and degrade it but cannot attach to and degrade crystalline plastic Current literature has brushed around this topic but we have been able to quantify it We have also been able to show that plastic can be converted between different levels of crystallinity through melting at high temperatures By freezing the plastic quickly we can obtain amorphous plastic, letting the plastic cool slowly yields crystalline plastic This data can be seen in the graph below

Research Objective 1: Separation of Ideonella from E. coli

We have already begun research in ways separate our plastic degrading bacteria from other bacteria. The enzyme that breaks the polymer bonds is a strong esterase that also catalyzed reactions in p-nitrophenyl acetate, as well as fluorescein diacetate (FDA). Utilizing FDA in a top agar allows for the identification of bacteria that produce this esterase. Developing this technique further to better screen for our bacteria is the first step in being able to identify the bacteria and isolate it from other bacteria in a sample. By mixing the bacteria of interest with another bacteria that has different colony morphology allows for easier identification of the bacteria of interest. A further project of the lab has been screening for constituently active petase among Ideonella mutants as seen in figure 1. We believe screening between Ideonella and E. coli to be more straightforward. By isolating our bacteria that we know degrades plastic from E. coli, another bacteria with a different morphology that is easy to differentiate, we can formulate a procedure that can isolate plastic degrading bacteria from soil samples. We have used PNPA assays in our mutagenesis experiments and can utilize a similar procedure in this screening process.

Research Objective 3: Isolation of a new plastic degrading bacteria

Research steps one and two are meant to build competency and test a procedure to confirm that the procedure works, and it is possible to isolate a plastic degrading bacterium. Our procedure is based on past research by other labs who isolated plastic degrading bacteria. We will finalize our modified procedure and begin our attempt to isolate a bacteria species locally. This will be performed through environmental sampling of areas locally that are known to have plastic contamination, including recycling centers, land fills, and junk yards. The samples will then be put through a similar screening method in the hopes of finding a bacteria that can use plastic as a carbon source. Ideonella is currently the only known strain of bacteria to have the PETase enzyme to break the polymer links of PET plastic. The hope is to find another bacteria that can also deteriorate PET, but other forms of plastic will also be used in a larger scope of the project to identify any strain of bacteria that can break down previously thought non-biodegradable plastic.

We can begin to test our procedure by trying to isolate bacteria that have potential plastic degrading properties.

Steps

1. Environmental sampling at local land fills, junk yards, and recycling centers

2. Procedure to isolate bacteria

3. Cataloging bacteria and testing for plastic degradation effectiveness.

Significance

The figure above illustrates the two enzymes Ideonella utilizes to first cleave the polymer chain of plastic and then break the monomer down into two products. The terephthalic acid can be recovered to make new plastic, and the ethelene glycol is used by the bacteria as a carbon source.

Some literature has shown that purified PETase the active enzyme in Ideonella can degrade highly crystalline plastic Our research has shown that when another carbon source is available the bacteria stops producing the enzyme The next step in the research method would be to mutate the bacteria to try and force the bacteria to always produce the enzyme – producing constituent PETase regardless of conditions This has not been very succeful as the bacteria is challenging to work with an we have not been able to force a plasmid into the bacteria As such, we tried random mutations trying to keep the bacteria producing constituent PETase through random mutation with UV light This methodology required a screening procedure, and this is how we developed the PNPA Top Agar assay that we will later use in high throughput screening of new species of bacteria Random mutations is a long, often unfruitful endeavor, we have had some success, but it has been limited

Through our different experiments we have developed new methodologies that we believe can be leveraged in an effort to cut down the screening time of isolating new species of plastic degrading bacteria Building a library of different species could be very beneficial to the scientific community Finding a bacteria with a constituently active PETase enzyme, a bacteria that more readily accepts foreign plasmids, or a bacteria that can adhere to and degrade highly crystalline plastic would all push the field significantly forward Current screening methodology takes between four and six months We believe that with our new assays we can cut the screening time down considerably Faster screening time for environmental samples will allow for more screening It is believed there ae many forms of plastic degrading bacteria that have evolved independently from one another, we just need to find them

Research Objective 2: Isolation of Ideonella from an inoculated soil sample

A sample of our known plastic degrading bacteria will be added to a sample of soil and we will attempt to reisolate. This will be done by following a few known procedures used for environmental samplings - Serial dilutions and limiting dilutions procedures. Rationale: This will allow us to test our procedure to determine if it works to find plastic degrading bacteria. By adding our bacteria that we know can deteriorate plastic we have a positive control for the experiment. Our preliminary work making minimal media plates that only Ideonella can grow on have been successful and we can use these plates to isolate the bacteria from unwanted species.

Plastic is a leading environmental concern and there need to be new and innovative ways to get rid of plastic. Current recycling processes are lacking and unable to fully remove plastic from the environment. There have been several forms of bacteria that can break down a number of different plastics but other strains need to be researched. Ideonella was the first bacteria discovered to degrade PET plastic but is still ineffective at degrading highly crystalline plastic. Much of our single use plastic is highly crystalline so further work needs to be done to combat this plastic. Understanding new ways to degrade plastic with the final goal of plastic removal from the environment is of interest. Having a library of different bacteria that can degrade plastic can help show new ways to accomplish this goal. Building a procedure to effectively sample for such specific bacteria needs to be developed.

References

1.https://www.bbc.co.uk/newsround/42810179J.

2.https://www.sciencealert.com/new-plastic-munching-bacteriacould-fuel-a-recycling-revolution

Yang, Y., Yang, J., & Jiang, L. (2016). Comment on "A bacterium that degrades and assimilates poly(ethylene terephthalate)". Science, 353(6301), 759–759. doi 10.1126/science.aaf8305

Yoshida, S., Hiraga, K., Takehana, T., Taniguchi, I., Yamaji H., Maeda, Y., … Oda, K. (2016). A bacterium that degrades and assimilates poly(ethyleneterephthalate). Science, 351(6278), 1196–1199. doi:10.1126/science.aad6359

ability to fully digest plastic

Plating our bacteria on minimal media M9 Agar plates

Our cultured bacteria (white) as well as a contaminant (Yellow)

Acknowledgements

This work was supported by a 2018 Small Project Research Grant from VAS and by funds from CNU to TDG. Additional preliminary experiments on PETase assay development, Ideonella culturing procedures, and alternative ways to measure degradation were performed by Mary Adams, Andrew Chafin, Diamonte Jones, Carson Pittman (HRA), Caroline Tsui, and Sam Tyler.

30
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Figure 1. Samples of mutated Ideonella that express Petase in the presence of other carbon sources. A top agar of fluorescein diacetate fluoresces brighter in the presence of the esterase.
2
Extended growth experiment showing the bacteria’s

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