Filter and Sort







PHYS2019LEE28437 PHYS

Investigating Modulation of Graphene Oxide Fluorescence via External Electric Fields

Type: Graduate
Author(s): Bong Han Lee Physics & Astronomy Fabian Grote Physics & Astronomy Thomas Paz Physics & Astronomy Conor Ryan Physics & Astronomy Alina Valimukhametova Physics & Astronomy
Advisor(s): Anton V. Naumov Physics & Astronomy
Location: Session: 1; Basement; Table Number: 5

presentation location

With the advent of graphene, there has been an interest in utilizing this material and its derivative, graphene oxide (GO) for novel applications in nanodevices such as bio and gas sensors, solid state supercapacitors and solar cells. Although GO exhibits lower conductivity and structural stability, it possesses an energy band gap that enables fluorescence emission in the visible/near infrared leading to a plethora of optoelectronic applications. In order to allow fine-tuning of its optical properties in the device geometry, new physical techniques are required that unlike existing chemical approaches yield substantial alteration of GO structure. Such desired new technique is one that is electronically-controlled and lead to reversible changes in GO optoelectronic properties. In this work, we for the first time investigate the methods to controllably alter the optical response of GO with the electric field and provide theoretical modelling of the electric field-induced changes. Field-dependent GO emission is studied in bulk GO/PVP films with up to 6% reversible decrease under 1.6 V/µm electric fields. On an individual flake level, a more substantial over 50% quenching is achieved for select GO flakes in polymeric matrix between interdigitated microelectrodes subject to two orders of magnitude higher fields. This effect is modelled on a single exciton level by utilizing WKB approximation for electron escape form the exciton potential well. In an aqueous suspension at low fields GO flakes exhibit electrophoretic migration indicating a degree of charge separation and a possibility of manipulating GO materials on a single-flake level to assemble electric field-controlled microelectronics. As a result of this work, we suggest the potential of varying the optical and electronic properties of GO via the electric field for the advancement and control over its optoelectronic device applications.

View Presentation

PHYS2019MCCARTHY57534 PHYS

Effect of the Hill coefficient on estimates of drug efficacy

Type: Undergraduate
Author(s): Gabriel McCarthy Physics & Astronomy
Advisor(s): Hana Dobrovolny Physics & Astronomy
Location: Session: 2; 2nd Floor; Table Number: 6

presentation location

We are modeling the effect of the Hill coefficient on the volume of a tumor. This is to test drugs that may bind to multiple receptors and compare them to each other. We are using Python and used 4 main parameters and one equation. We modeled the Volume and the Dose Response Curves as well as the Emax and Ic50. We used the different positive Hill Coefficients and studied the effect on dose and carrying capacity.

View Presentation

PHYS2019MCKINNEY32467 PHYS

Nitrogen-Doped Graphene Quantum Dots and Reduced Graphene Quantum Dots for Intensity Luminescence Nanothermometry

Type: Undergraduate
Author(s): Tanvir Hasan Physics & Astronomy Bong Han Lee Physics & Astronomy
Advisor(s): Anton Naumov Physics & Astronomy
Location: Session: 1; 3rd Floor; Table Number: 4

presentation location

Non-invasive temperature sensing is necessary for the analysis of biological processes occurring in the human body including cellular enzyme activity, protein expression, and ion regulation. Considering that a variety of such biological processes occur at the microscopic scale, a novel mechanism allowing for the detection of the temperature changes in microscopic environments is desired. One-dimensional graphene quantum dots can serve as agents for such detection: they are promising non-invasive probes that because of their 2-5 nm size and optical sensitivity to temperature change enable sub-cellular resolution imaging. Both biocompatible bottom-up synthesized nitrogen-doped graphene quantum dots and quantum dots produced from reduced graphene oxide via top-down approach exhibit temperature-induced fluorescence variations. This response observed for the first time is utilized for deterministic temperature sensing in bulk suspension as well as inside mammalian cells. Distinctive quenching of quantum dot fluorescence by up to 19.8 % is observed, in a temperature range from 25℃ to 49℃, in aqueous solution, while the intensity is restored to the original values as the temperature decreases back to 25℃. A similar trend is observed in vitro in HeLa cells as the cellular temperature is increased from 25℃ to 41℃. Our findings suggest that the temperature-dependent fluorescence quenching of bottom-up and top-down-synthesized graphene quantum dots can serve as non-invasive reversible deterministic mechanism for temperature sensing in microscopic sub-cellular biological environments.

View Presentation

PHYS2019MURPHY60207 PHYS

Understanding the Effect of Measurement Time on Drug Characterization

Type: Graduate
Author(s): Hope Murphy Physics & Astronomy
Advisor(s): Hana Dobrovolny Physics & Astronomy
Location: Session: 1; Basement; Table Number: 1

presentation location

In order to determine correct dosage of chemotherapy drugs, the effect of the drug must be properly quantified. There are two important values that characterize the effect of the drug: ε_max is the maximum possible effect from a drug, and IC_50 is the drug concentration where the effect diminishes by half. We use mathematical models to estimate how the values depend on measurement time and model choice. Improper choice of growth model is problematic and can lead to differences in predictions of treatment outcomes for patients. This work intends to understand how choice of model and measurement time affects the relative drug effect and causes the differences in predictions for the most effective dose of anticancer drug for a patient. This work determines the correct doses before trying those in patients to get the most effective therapeutic treatment.

View Presentation

PHYS2019PHO52926 PHYS

Effect of Noise applied to Simulated Cancer Growth Model on the Error in Assessment of Anti-Cancer Drug Efficacy

Type: Undergraduate
Author(s): Christine Pho Physics & Astronomy Madison Frieler Biology Angel Guyton Biology
Advisor(s): Hana Dobrovolny Physics & Astronomy Giridhar Akkaraju Biology Anton Naumov Physics & Astronomy
Location: Session: 1; Basement; Table Number: 11

presentation location

New anti-cancer drugs are constantly being developed and tested. Effectiveness of these drugs is currently assessed by measuring the reduction in number of cancer cells cultured in experiments as a function of the applied drug dose. These measurements determine the drug dose needed to achieve half of the maximum reduction in cells (IC50) and the maximum effect of the drug (εmax). However, the technique that measures values of IC50 and εmax depends on the time chosen to make the measurements. We have developed a method to analyze the growth of cancer cells in different concentrations of drugs that will provide estimates of both parameters that are independent of measurement time. Here, we computationally simulated the growth of cancer cells according to a logarithmic model, adding different levels of noise. And, we found the error in IC50 and εmax as a function of the level of noise. Development of this new technique will lead to more consistent measurement of the efficacy of known and novel anti-cancer therapies.

(Presentation is private)

PHYS2019RAY53904 PHYS

Shooting for Star Cluster Chemical Abundances with The Cannon

Type: Graduate
Author(s): Amy Ray Physics & Astronomy
Advisor(s): Peter Frinchaboy Physics & Astronomy
Location: Session: 1; 3rd Floor; Table Number: 1

presentation location

Star clusters are key chemical and age tracers of Milky Way evolution. The use of star clusters to provide significant constraints on galaxy evolution, however, has been limited due to discrepancies between different studies. This work seeks to add additional open clusters into an existing large, uniform chemical abundance system. We analyze spectra of giant stars in 31 open clusters and, using a machine learning method called The Cannon, determine iron abundances. This uniform analysis is compared with previous results, and we present new chemical abundances of 12 star clusters.

View Presentation

PHYS2019REEKS46081 PHYS

Does surface polarity of micro- and nano-scale ZnO particles contribute to antibacterial action?

Type: Graduate
Author(s): John Reeks Physics & Astronomy Tabitha Haun Physics & Astronomy Benite Ishimwe Environmental Sciences Bao Thach Engineering Jacob Tzoka Physics & Astronomy Kimon Vogt Engineering
Advisor(s): Yuri Strzhemechny Physics & Astronomy
Location: Session: 2; 3rd Floor; Table Number: 4

presentation location

Antimicrobial action of micro- and nanoscale ZnO particles has been documented, but the fundamental physical mechanisms driving this action are still not identified . We hypothesize that one of the key mechanisms behind the antibacterial action of ZnO is rooted in interactions between ZnO surfaces and extracellular material. Crystalline structure of ZnO results in two distinct types of crystallographic surfaces: polar (charged) and non-polar (neutral). The excess charge and electronic states at the polar surfaces of micro- and nano-scale ZnO particles may affect interfacial phenomena with surrounding media. Therefore, it is feasible that the relative abundance of such polar surfaces could significantly influence their antibacterial action. In this study we use a hydrothermal growth method established in our lab to synthesize ZnO crystals with different controllable surface morphologies. We study the effects of relative abundance of polar surfaces on antibacterial action. These experiments performed in conjunction with optoelectronic studies of ZnO crystals yield information regarding the fundamental nature of their antibacterial action.

View Presentation

PHYS2019REEKS6818 PHYS

UV-driven stimulated hydrophilicity of hydrophobic polysulfone

Type: Graduate
Author(s): John Reeks Physics & Astronomy Tabitha Haun Physics & Astronomy Benite Ishimwe Environmental Sciences
Advisor(s): Yuri Strzhemechny Physics & Astronomy
Location: Session: 1; 3rd Floor; Table Number: 4

presentation location

Polysulfone is a stable and strong semitransparent thermoplastic material that is applicable in many industries due to its resistance to low and high temperatures, as well as unique hydrophobic properties. Hydrophobic films are frequently used in waterproofing devices and to improve the efficiency of water vessels. It was recently discovered that polysulfone has a unique behavior as it changes from being hydrophobic to hydrophilic after exposure to a UV radiation. In order to elucidate the mechanisms behind this phenomenon we are performing surface photovoltage (SPV) studies on polysulfone thin films, which is done for the first time, to the best of our knowledge. Whereas SPV is sensitive to buried interfaces, SPV spectral features contain contributions not only from the polysulfone films, but from the silicon wafer and the silicon oxide layer beneath the polymer films. Thereby, to identify the signal germane to the polysulfone properly, we employ in our studies polysulfone films of varying and controllable thicknesses. To establish controllable methods for producing such films by spin coating, we use different concentrations of polysulfone in solutions with different spin rates. Film thickness is determined employing a thin film analyzer. From these thicknesses, trends are established relating film thickness to solution concentration and spin rate. SPV studies provide initial investigations into surface electronic transitions and mechanisms behind the hydrophobic ‘flipping’ of polysulfone.

View Presentation

PHYS2019RYAN42727 PHYS

Construction and Implementation of a High-Powered Multi-Laser Excitation System

Type: Undergraduate
Author(s): Conor Ryan Physics & Astronomy Tanvir Hasan Physics & Astronomy
Advisor(s): Anton Naumov Physics & Astronomy
Location: Session: 1; 2nd Floor; Table Number: 6

presentation location

High-power laser excitation systems are critical in observing and studying nanomaterials and their optoelectronic properties on a single specie level. These systems enable inducing fluorescence and observing emission microscopically from individual flakes and or molecules. As the fluorescence of nanomaterials is often excitation dependent, multiple laser with different frequencies are needed to probe their optical properties. In this work we construct such multi-laser setup to use for a microscopy system to enable imaging nanocarbons: flakes of functional derivatives of graphene, carbon nanotubes, and graphene quantum dots.
The system is composed of four lasers of varying wavelength: blue at 450 nm, green at 532 nm, red at 637 nm, and near-infrared (NIR) at 808 nm. An additional near-infrared laser at 980 nm is included for special applications with deep NIR imaging. These lasers were set up to be turned on and off remotely and traverse through a system of dichroic and regular mirrors and a periscope coupled to a fluorescence microscope. A neutral density filter wheel designed and set up in the light path enables altering the intensity of the lasers leading to optimized fluorescence and imaging. The resulting laser set up allowed effective imaging of graphene oxide flakes, graphene quantum dots, and carbon nanotubes both on a microscope slide and in biological cells and tissues.

View Presentation

PHYS2019STONE31461 PHYS

Nanomaterials-Assisted Antibiotic Delivery

Type: Undergraduate
Author(s): Lindsey Stone Physics & Astronomy
Advisor(s): Dr Anton Naumov Physics & Astronomy Dr Shauna McGillivray Biology
Location: Session: 2; 3rd Floor; Table Number: 1

presentation location

The goal of this project was to engineer complexes of antibiotics and nanomaterials that address gram negative bacteria more efficiently than antibiotics alone. The gram-negative class of bacteria has two cell membranes, as opposed to the gram-positive class which has only one; this second membrane poses an additional challenge for antibiotic cell entry. Theoretically, the amphiphilic nanomaterials may aid the antibiotics by assisting them through both membranes and masking their entry. A number of nanomaterials were tested including graphene quantum dots, single-walled carbon nanotubes, and graphene oxide, and antibiotics including Penicillin, Methicillin, Amoxicillin, Norfloxacin and Linezolid were tested as well. Carbon nanotubes were supplemented with polyethylene-glycol coating agent, while water-soluble GQDs and graphene oxide were used as synthesized in our laboratory. The complex of the antibiotic Norfloxacin and Graphene Quantum Dots (GQDs) was selected as the most efficacious. It allowed killing of the gram-negative bacteria E. Coli at moderate concentrations significantly more efficiently than unaccompanied Norfloxacin. Its colocalization with bacteria was verified via high quantum yield (over 62%) intrinsic fluorescence of GQDs in the visible. This may lead to substantial improvement of antibacterial techniques against gram negative bacteria, increase in antibiotic efficacy, and potentially the recycling of antibiotics to which bacteria exhibit resistance.

(Presentation is private)

PHYS2019SUN49284 PHYS

The environmental effect on star formation in low-mass galaxies.

Type: Graduate
Author(s): Jing Sun Physics & Astronomy Kat Barger Physics & Astronomy
Advisor(s): Kat Barger Physics & Astronomy
Location: Session: 2; Basement; Table Number: 8

presentation location

The interaction between low-mass galaxies are of critical importance for the growth and evolution of galaxies. The star formation can be enhanced during interactions between massive galaxies, but very few studies focus on the interaction between low-mass galaxies. In this work, we explored the current star-formation surface density in both isolated and interacting galaxies and look for enhanced star formation during the interactions. A galaxy will be considered as a galaxy pair candidate if the physical separation between it and its closest low-mass galaxies is smaller than 5000 light years, otherwise it will be put into the isolate galaxy sample. This sample intentionally excludes galaxies with a massive galaxy neighbor nearby as massive neighbors can harass low-mass companion galaxies and can cause them to become quenched. This project is the first attempt to systematically study how the internal star-formation activities of low-mass galaxies are influenced by outer environment.

View Presentation

PHYS2019WEERASOORIYA61969 PHYS

Star Wells: Rise of Satellites

Type: Graduate
Author(s): Sachithra Weerasooriya Physics & Astronomy
Advisor(s): Mia Bovill Physics & Astronomy
Location: Session: 2; 3rd Floor; Table Number: 10

presentation location

Large galaxies are made up of smaller satellite galaxies. This makes these satellite galaxies crucial to understanding how stars form. Shallow gravity wells make them extremely sensitive to internal and external disturbances. Therefore, they are excellent laboratories to explore stellar physics. We use multi-body simulations of a Milky Way-like galaxy to explore the stellar properties of satellite galaxies surrounding a possible Large Magellanic Cloud (LMC). LMC is the largest satellite galaxy of the Milky Way. We compare the resulting properties such as chemical composition, light, radial distribution to observations from McConnachie et al. 2012.

View Presentation

PSYC2019AVELAR29440 PSYC

Relationship Specific Meaning in Life (MIL) Buffers Against Fear of Mortality

Type: Undergraduate
Author(s): Elidia Avelar Psychology Arielle Cenin Psychology Bryn Lohrberg Psychology Elise Martinez Psychology
Advisor(s): Cathy Cox Psychology
Location: Session: 1; 1st Floor; Table Number: 1

presentation location

Terror management theory is a theory that proposes mortality salience, or the awareness of the inevitability of death, is a motivating factor for maintaining faith in cultural worldviews and personal growth in value and self-esteem. Following mortality salience, people are more likely to interact with others and express satisfaction in relationships. Meaning in life (MIL) research is interested in examining the purpose and significance one feels in relation to their personal lives. Research has found that high MIL is associated with increased feelings of social connectedness and sense of belonging. (Baumeister & Vohs, 2002) The present research examined the link between mortality concerns, relationship MIL, and satisfaction/commitment within people’s romantic partners. In the research 369 participants ranging from ages 17-43 were asked to complete a lexical decision task that could be filled with death or neutral related words. Participants also completed a 5- item measure of relationship-specific MIL. Finally, participants completed a measure recording their relationship satisfaction. It was hypothesized that increased death awareness would lead to greater pursuit in MIL in people’s relationship with their romantic partner. The results showed that people with elevated DTA also have higher scores on relationship specific meaning in life. That is, higher DTA was related to greater search for meaning from relationships. This, in turn, was related to increased relationship satisfaction and commitment scores.

View Presentation

PSYC2019BENTLEY40614 PSYC

The Role of Death Concerns in the Use of Force Among Police Officers

Type: Undergraduate
Author(s): Hope Bentley Psychology Lexie Bryant Psychology Anita Pai Psychology
Advisor(s): Cathy Cox Psychology
Location: Session: 2; Basement; Table Number: 10

presentation location

From the perspective of terror management theory, reminders of death are problematic because they lead individuals to defend their cultural beliefs. Given that police officers are trained to see persons and situations as potentially dangerous (i.e., naturally occurring mortality salience), this may result in greater acceptance of the use of force. The current study examined police officers’ reactions to arrest vignettes and fear of death. Results suggest that increased death awareness predicted greater use of unnecessary force. These effects held while controlling for several individual differences that have previously been shown to influence use of force. These findings suggests that death concerns play an important role in how police officers respond to crime.

View Presentation

PSYC2019DUKES19806 PSYC

The peripheral antecedents of the decision to act

Type: Undergraduate
Author(s): Jacque Dukes Psychology Abby Duplechain Psychology Andrea Farias Psychology Bells Vo Psychology Sam Wharton Psychology
Advisor(s): Brenton Cooper Psychology
Location: Session: 2; 1st Floor; Table Number: 1

presentation location

How does one decide to act? In humans, the “decision” to initiate a behavior can occur several seconds before an action is undertaken and can even occur without conscious awareness. Here we explore whether we can predict when a nonhuman animal is going to engage in a self-initiated behavior.
Singing in songbirds is a learned behavior that is passed down from one generation to the next via imitative learning. Birds initiate song in response to the presentation of a female bird (directed) or spontaneously when in isolation from other birds (undirected). The production of song requires the control of respiratory, vocal organ, and upper vocal tract motor systems; these diverse motor systems are controlled by the activation of precise neural networks within specific areas of the songbird brain. Although much is known about the neuromuscular control of song, the neural and peripheral mechanisms underlying song initiation and termination have received less attention. Here we explore in two songbird species whether song initiation and termination can be predicted by measuring changes in respiratory patterns prior to, during, and after song. We quantified changes in respiratory rate and amplitude, as well as changes in time spent in the inspiratory versus expiratory cycle to determine whether specific features of respiration were tied to onset or offset of song. Measurements of respiratory patterns were undertaken in zebra finches (Taeniopyggia guttata) and Bengalese finches (Lonchura striata var. domestica). Preliminary data suggest that respiratory patterns change predictably within the last second prior to when a bird initiates song. Following song, there is clear evidence of respiratory changes due singing-related exertion. Our findings illustrate that the occurrence of self-initiated behaviors can be predicted by exploring peripheral song motor control up to one second prior to the onset of the behavior. These results illustrate that the decision to act can be predicted by changes in peripheral motor systems which likely serve as preparatory activity for the upcoming motor action.

View Presentation

PSYC2019GUARINO44570 PSYC

Role of the Central Amygdala in Loss-induced Emotional Self-medication

Type: Graduate
Author(s): Sara Guarino Psychology Shannon Conrad Psychology Mauricio Papini Psychology Zach Wade Psychology
Advisor(s): Mauricio Papini Psychology
Location: Session: 2; Basement; Table Number: 12

presentation location

The present experiment was designed to explore the role of the central amygdala (CeA) in the hypothesized neural circuit underlying reward loss, and its relationship with the emotional self-medication (ESM) hypothesis utilizing the DREADD technique to remotely control neural activity. Rats received intracranial infusion of inhibitory DREADDs to allow for transient inactivation of the CeA, obtained via systemic injection of clozapine N-oxide (CNO), the activator drug for DREADDs. Animals were exposed to a 32-to-2% sucrose downshift in the consummatory successive negative contrast (cSNC) situation. After each cSNC session, animals were given simultaneous access to ethanol and water in a 1-h, two-bottle preference test. During the preshift phase (sessions 1-10), animals had access to either 32% (32/CNO and 32/VEH) or 2% (2/CNO and 2/VEH) sucrose. During the postshift phase (sessions 1-15), 32% groups were downshifted to 2% sucrose, whereas 2% groups were unshifted. Prior to downshifted sessions 11-13, animals received an i.p. injection of either CNO or vehicle. At the end of the 15-day two-task behavioral paradigm, animals were tested on the open-field task for two consecutive days in alternate dark and light conditions. The results indicated that CeA inactivation prior to reward devaluation session eliminated the cSNC effect (32/CNO), a hint of ESM effect was present in animals that experienced the reward devaluation under normal CeA activity (32/VEH), but not in animals for which the CeA was inhibited (32/VEH), and open-field activity showed a trend, albeit nonsignificant, toward increased activity in animals with inhibited CeA activity (32/CNO). One important contribution of this experiment involves the use of the DREADD technique to achieve transient inactivation of brain regions. This approach produced behavioral consequences in the cSNC task similar to those obtained in previous research using lidocaine microinfusions. The results of this study suggest that the DREADD approach is a valuable method to manipulate neural activity to further explore the role of these brain regions in our hypothesized reward loss circuitry.

View Presentation

PSYC2019GUYTON22707 PSYC

Spirituality Resilience Training as a Method of Treatment in Morally Injured Veterans

Type: Undergraduate
Author(s): Nathan Guyton Psychology Vishal Thakkar Psychology
Advisor(s): Timothy Barth Psychology
Location: Session: 2; 2nd Floor; Table Number: 6

presentation location

Moral injury is the psychological or spiritual consequence of acting (or failing to act) in a manner that is inconsistent with one’s moral code (Litz et al., 2009; Shay, 1994). The goal of this research was to test a spiritual resilience training program on those with moral injury and their perceived stress and growth. We administered a survey of 21 psychologically validated scales to veterans before the training sessions and one week apart after they ended. Specifically, we were interested in seeing how those who completed a one-week training program would respond to measures of perceived stress, post-traumatic growth, and moral injury, as compared to a control group that did not complete the training. Those who completed the training went through a program of group discussion, journal activities, art therapy, and individual reflection. We found that veterans who completed the program had higher ratings of: post-traumatic growth, relating to others, and sense of spirituality. There were no differences in self-reported perceived stress. The results of the current study could provide more insight into how the training program works and if the program assists veterans in acclimating to life after possible traumatic events during deployment.

View Presentation

PSYC2019HAYES32319 PSYC

Ovulation, Stimulus Discrimination, and Mate Preferences

Type: Undergraduate
Author(s): Rylie Hayes Psychology Maddie Kloess Psychology Summer Mengelkoch Psychology
Advisor(s): Sarah Hill Psychology
Location: Session: 2; Basement; Table Number: 6

presentation location

Past research in evolutionary psychology has found that women experience shifts in their mate preferences during ovulation - the few days in a month in which conception is possible. Specifically, ovulating women show an increased preference towards men with greater levels of masculinity, facial symmetry, and creative ability. These traits are thought to be indicators of a high-quality mate, and as such women are thought to be attuned to these traits when conception is possible. To extend this research, we sought to examine whether this effect was driven by changes in women’s abilities to detect subtle differences in these traits. To do so, we tested women’s ability to discriminate between mating related stimuli, including slight changes in facial symmetry and masculinity, gait masculinity, and creativity, at both ovulation and a low fertility point in their ovulatory cycles. We are collecting a sample of 240 women – 120 who are taking hormonal contraceptives, and 120 who are naturally cycling. We predict that ovulating, natural cycling women will be better able to detect subtle differences in mating related stimuli compared to naturally cycling, low fertility women, as well as those women taking hormonal contraceptives. Preliminary results will reveal if ovulating women are better able to detect these differences and if they are more attuned to the quality of potential mates.

View Presentation

PSYC2019HILL54918 PSYC

5xFAD mice display cognitive impairment in a novel object placement task

Type: Undergraduate
Author(s): Briar Hill Psychology Kelly Brice Psychology Christopher Hagen Psychology Lauren McCue Psychology Julia Peterman Psychology Jordon White Psychology
Advisor(s): Gary Boehm Psychology Michael Chumley Biology
Location: Session: 1; 3rd Floor; Table Number: 6

presentation location

One of the main hallmarks of Alzheimer’s disease (AD) is dramatic cognitive decline, including memory loss. Because of this, AD research continually seeks new ways to study the cognitive health of animal models of AD. Researchers have assessed cognitive deficits in AD mice through a variety of behavioral paradigms. The purpose of the present study is to assess if mice with AD-like markers display cognitive deficits in an additional behavioral paradigm, the Novel Object Placement (NOP) task. Animals are allowed to explore two identical objects in a testing arena for three sessions of five minutes. In a fourth session, one of the objects is moved to a different spot in the arena. Animals with intact cognition spend more time exploring the object in the novel location than the object in its original location, as mice naturally display a preference for novelty. Pilot data from our lab demonstrates that experimentally naïve animals complete the task successfully. The animals used in this study are 5xFAD transgenic mice, nontransgenic mice, and nontransgenic mice administered LPS. 5xFAD mice have genetic mutations that result in the production of a protein, amyloid beta, that is seen in human AD, and is often associated with cognitive deficits. Additionally, our lab has previously demonstrated that nontransgenic mice administered seven consecutive days of LPS, a bacterial mimetic, also produce amyloid beta. To investigate if both of these mice display deficits in NOP, we gave nontransgenic 5-6 month-old mice seven days of either LPS or saline injections, and we gave 5xFAD animals saline injections. For the next three days following the 7th injection, the animals were placed into the testing arena with identical objects in adjacent corners of the arena and allowed to explore. Four hours after the third training session, one of the objects was moved to a new location in the arena, and animals were placed back into the arena for the testing session. The dependent variable was the percentage of total object exploration time spent exploring the object in the novel location. There were no significant differences between the nontransgenic animals that received LPS or saline. However, the 5xFAD animals spent significantly less time exploring the novel object compared to the nontransgenic animals, indicating impairment identifying the novel object location. Therefore, at 5-6 months of age, the 5xFAD mice demonstrated cognitive deficits in the NOP task. Further research will explore at what age these cognitive deficits emerge and the extent to which various AD markers are correlated with the deficits.

View Presentation

PSYC2019HUNSLEY5655 PSYC

Understanding the Adoptive Sibling Experience

Type: Graduate
Author(s): Jana Hunsley Psychology
Advisor(s): David Cross Psychology Rachel Crawley Psychology
Location: Session: 2; 2nd Floor; Table Number: 4

presentation location

Research has explored the effects of adoption on the adopted child as well as the parent-child relationship in an adoptive family. However, little is known about the effects of adoption on the remaining members of an adoptive family—the adoptive siblings, defined as the biological children in families who adopted one or more children. The current study aims to examine the adoptive sibling experience in effort to understand a) the effects of adoption on this population and b) which, if any, precluding factors are related to these effects. Participants included adult siblings to at least one adoptee who completed an online survey about their family and experiences. The survey included items about family demographics, free-response items about specific adoption experiences, a measure of potential risk and protective factors created for this study, and assessments about sibling relationship quality and overall family functioning. Results revealed five emerging themes in the adoptive sibling experience: 1) “my adoptive sibling was the best thing to happen to our family,” 2) “it was a hard experience but has shaped me to be who I am today,” 3) “my adoptive sibling required all my parents’ attention and I was pushed aside,” 4) “I am like a second parent to my adoptive sibling,” and 5) “it was the worst thing to ever happen to our family.” Results also revealed that better family communication and greater siblings’ involvement in the adoption process are related to a more positive response to adoption, a closer relationship with the adopted sibling, and more positive views of the family system. Findings improve our preliminary understanding of how adoption affects adoptive siblings and imply that targeted interventions for adoptive siblings may be needed; however, more research is needed to better understand the factors involved.

View Presentation

PSYC2019JI1519 PSYC

The Effects of Meaning in Life on Academic Achievement

Type: Undergraduate
Author(s): Karen Ji Psychology Robert Arrowood Psychology Lexie Bryant Psychology Christina Ostovich Psychology
Advisor(s): Cathy Cox Psychology
Location: Session: 1; Basement; Table Number: 7

presentation location

In an effort to improve academic achievement, we examined the effects of meaning in life (MIL) on grade performance. Prior research has found that MIL is associated with better adjustment to stressful life events. Fall semester freshmen in general psychology courses were asked to complete measures of MIL and academic adjustment. At the end of the semester, their final grades from general psychology courses were collected from the Registrars’ office. The results revealed that higher meaning presence persons reported experiencing better academic adjustment to college. Higher adjustment was associated with increased end of the semester final grades in general psychology . No effects emerged in response to meaning search. These findings suggest that the presence of MIL in early college life could have important implications for academic well-being and achievement.

View Presentation

PSYC2019JOHNSON28463 PSYC

Effects of Unpredictable Stress on Contextual Acquisition and Extinction in Mouse Models of Alzheimer’s Disease

Type: Undergraduate
Author(s): Madison Johnson Biology Kelly Brice Psychology Christopher Hagan Biology Taylor Jamali Biology Julia Peterman Psychology Jordan White Psychology
Advisor(s): Gary Boehm Psychology Michael Chumley Biology
Location: Session: 1; 2nd Floor; Table Number: 8

presentation location

Alzheimer’s disease (AD) is a progressive form of dementia marked by decline in cognitive functioning and memory loss due to protein abnormalities in the brain. One early cognitive deficit seen in AD is a contextual acquisition deficit. However, evidence suggests that deficits in contextual extinction learning may present earlier than acquisition deficits. Extinction is a type of learning process by which the brain acquires information inconsistent with information it had previously learned, and gradually begins to accept this new information instead of the old. As psychological stress has been linked with increased Alzheimer’s markers, it is important to explore the interaction between stress and contextual learning.
In our first experiment, male C57BL/6J mice were divided into three groups – unpredictable stress (US), isolation, and group housed (controls). All three groups were trained in a contextual fear conditioning. After training, the animals in the isolation and US groups were isolated in individual cages for seven days. In addition to living in isolation, the US group underwent seven days of variable, unpredictable stressors which include 2 hours of wet bedding, cage tilted at 45 degrees for 30 minutes, 30 minutes of restraint stress, 5 minutes of forced swimming in warm water, placement in an empty cage for one hour, and nesting material removal overnight. These stressors were applied in a random order every day for 7 days. On the eighth day, acquisition learning was assessed. Animals in the US group showed significant deficits in acquisition of contextual fear conditioning compared to isolated animals and group housed controls. Extinction learning was assessed on days nine through twelve. There was no effect of US on extinction learning, as there was likely a floor effect due to impaired acquisition. In the second experiment, animals were divided into US and a group housed control group. The US animals underwent the same series of stressors listed previously for six days. On the seventh day, all animals received one 250mg/kg injection of LPS, a bacterial mimetic, to determine how stress impacted the immune challenge. Four hours later, the hippocampus was collected for cytokine and HMGB1 mRNA analysis. As the elderly face surmounting odds of AD, along with significant stress, research on how these interact and early diagnostic signs is especially relevant.

View Presentation

PSYC2019JORDAN55617 PSYC

Do you hate the object, or the event it predicts? Devaluation of a conditioned reinforcer with rats

Type: Undergraduate
Author(s): Mackenzie Jordan Psychology Karen Borowski Psychology Cheyenne Elliot Psychology Kenneth Leising Psychology
Advisor(s): Kenneth Leising Psychology
Location: Session: 2; 3rd Floor; Table Number: 2

presentation location

Reinforcer devaluation involves pairing an appetitive stimulus (e.g., food) with an aversive event (e.g., illness), which disrupts the ability of the stimulus to elicit behavior (Adamson & Dickinson, 1981). The effect of reinforcer devaluation could be the result of the stimulus signaling the aversive event. Alternatively, exposure to the stimulus and aversive event together may result in a hedonic shift, or change in the affective unconditional properties of the stimulus. The two accounts make different predictions regarding the effect of reexposure to the devalued stimulus. The hedonic shift account describes reexposure to the stimulus as necessary to experience the changed value of the stimulus, but a signaling account can explain devaluation after one pairing. Balleiene & Dickinson (1991) found that reexposure to food paired with illness was necessary to observe a devaluation effect. The current experiment investigated the devaluation of a conditioned reinforcer. Rats were initially trained with pairings of an audiovisual (light and tone) stimulus with sugar water (sucrose). In the next phase, acquisition of a new behavior, lever pressing, was supported by presenting the stimulus (conditioned reinforcer) following a lever press. During devaluation, the experimental group received one trial of the stimulus paired with a shock, whereas the control group received the stimulus and shock, but separated in time (i.e., unpaired). In Test 1, all rats were given the opportunity to press the lever with no nominal consequences (e.g., no stimulus or shock). Then, all rats were re-exposed to the audiovisual stimulus without the lever or shock. In Test 2, lever pressing was measured as in Test 1. The data will be discussed in terms of the role of reexposure in devaluation.

References

Adams and Dickinson (1981). Instrumental responding following reinforce devaluation. The Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology, 33 (2), 109-121.

Balleine, B., & Dickinson, A. (1991). Instrumental performance following reinforcer devaluation depends upon incentive learning. The Quarterly Journal of Experimental Psychology, 43(3), 279-296.

View Presentation

PSYC2019LOHRBERG21661 PSYC

Relationships between Collegiate Athletes and Nostalgia

Type: Undergraduate
Author(s): Bryn Lohrberg Psychology Nathan Guyton Psychology Julie Swets Psychology
Advisor(s): Cathy Cox Psychology
Location: Session: 1; Basement; Table Number: 2

presentation location

There is empirical evidence that there is an association between nostalgia, or a sentimental longing for the past, and one’s psychological and social well-being. Additional research has shown that nostalgic reverie leads not only to increased optimism and positive attitudes towards preventative health behaviors, but also actual increased health behaviors. This study extends the research on nostalgia and health into the realm of college athletics and explores how collegiate athletes’ performance is correlated with nostalgic tendencies, in addition to various measures of well-being, optimism, meaning in life, vitality, and life satisfaction. A positive correlation is expected, such that higher performing athletes are also more nostalgia prone. This study will serve as a foundation to explore the direct benefits for athletes of nostalgic thought, the advantages of which are firmly supported in other contexts.

View Presentation

PSYC2019MILLER57456 PSYC

Effects of Echoic Response Interference on Emergent Naming

Type: Undergraduate
Author(s): Alexandra Miller Psychology Reagan Cox Psychology Anna Petursdottir Psychology Remington Swensson Psychology Alexandra Wilkins Psychology
Advisor(s): Anna Petursdottir Psychology
Location: Session: 2; Basement; Table Number: 5

presentation location

Covert echoing has been hypothesized to play a role in the emergence of stimulus control over vocal naming after a person is exposed to contiguous presentation of a novel object and its name. However, experimental evidence is weak. This study examined the effects of blocking echoic responses during exposure to name-object presentations on later vocal naming. Preschool-age children were exposed to pictures of national flags and heard the associated country names. In the echoic condition, participants were instructed to echo the country name presented in each trial. In the interference condition, they were instructed to name the background color on which the flag was presented in each trial, which was presumed to interfere with echoic responding. In the no-response-requirement (NRR) condition, participants were not instructed to make any responses. Flag naming was probed after each session. Only 3 of the 5 participants showed a tendency to name the flags vocally even after repeated exposure. Of these three, only one demonstrated poorer performance in the interference condition relative to the echoic and NRR conditions. These results fail to provide support for the echoic hypothesis and are consistent with other data from our lab.

View Presentation