PHYS2019CHAVEZ34578 PHYS
Type: Graduate
Author(s):
Jose Chavez
Physics & Astronomy
Luca Ceresa
Physics & Astronomy
Ignacy Gryczynski
Physics & Astronomy
Joe Kimball
Physics & Astronomy
Advisor(s):
Zygmunt Gryczynski
Physics & Astronomy
Location: Session: 2; 3rd Floor; Table Number: 2
View PresentationFluorescence has grown to be the most sensitive detection technique used in a variety of biophysical, biochemical and medical applications for several decades. However, there is an interesting luminescence similar to fluorescence which causes an “afterglow effect” (“glow in the dark”). This is called “phosphorescence”. Phosphorescence has an exceptionally longer lifetime (milli or microseconds) compared to fluorescence (nanoseconds). This can be up to a million times longer. Modern fluorescence lifetime measurements require sensitive detectors that cost several ten to hundreds of thousands of dollars, while a phosphorescence lifetime detector can be in the thousands range. This detector uses ocean optics spectrometry with a phosphoroscope to measure phosphorescence. With this application we want to use it for studying protein dynamics such as shape, spacing, binding, etc. The novelty for this approach is using tryptophan as a probe for direct excitation to the phosphorescence triplet state. This means the usual encounter of fluorescence there is a continuous light source. When exposed the sample will emit its fluorescence. Once removed from the light source, since fluorescence is so fast when decaying, will expire off. However, with phosphorescence, after the removal of the light source, the sample still emits. This procedure if successful will circumvent fluorescence and just achieve phosphorescence. To study this we will be using PVA (poly vinyl alcohol [plastic]) with 5,6 – Benzoquinoline, Indole, and Tryptophan where the first compound is confirmed to have phosphorescence able to be seen even with the naked eye at room temperature. These will be studied in a device that will measure phosphorescence called a fluorospectrometer (Varian Eclipse) and the phosphoroscope. With this information we can find out what color (wavelength) to excite the tryptophan and circumvent fluorescence to phosphorescence.
PHYS2019CIAMPA28285 PHYS
Type: Graduate
Author(s):
Drew Ciampa
Physics & Astronomy
Advisor(s):
Kat Barger
Physics & Astronomy
Location: Session: 1; Basement; Table Number: 6
View PresentationMassive amounts of gaseous material are being ejected from the nearby Large Magellanic Cloud (LMC) due to supernovae explosions occurring inside the galaxy. These explosions influence how gas cycles in and out of a galaxy and is crucial for our understanding of how galaxies evolve. Being the nearest gas-rich galaxy, the LMC provides us with an excellent opportunity to explore this gas cycle in detail. We have combined spectroscopically resolved observations to investigate the influence supernovae have on the LMC gas and the connection between supernovae explosions and the currently flowing galactic wind.
PHYS2019DONOR55459 PHYS
Type: Graduate
Author(s):
John Donor
Physics & Astronomy
John Wise
Physics & Astronomy
Advisor(s):
Peter Frinchaboy
Physics & Astronomy
Location: Session: 2; Basement; Table Number: 7
View PresentationThe problem of fitting isochrones, theoretical models of stellar populations, to the observed stellar populations (e.g. star clusters) has plagued observational astronomy for decades. A plethora of algorithms have been developed, but many fall short of their goals, and almost all are very computationally expensive. We present a new, computationally efficient technique made possible by first creating a fiducial representation of the data. This concise representation allows for a robust comparison to many theoretical models using a Markov-Chain Monte Carlo (MCMC) approach, quickly producing not only accurate fits but reasonable constraints on the final fitting parameters. The technique is applied to a number of star clusters, and the results are discussed in the context of Galactic chemical evolution.
PHYS2019FAIN18003 PHYS
Type: Graduate
Author(s):
Baylor Fain
Physics & Astronomy
Advisor(s):
Hana Dobrovolny
Physics & Astronomy
Location: Session: 2; 3rd Floor; Table Number: 7
View PresentationA virus spreads through a body in two known ways: free cell transmission and cell to cell transmission. During free cell transmission, cells make viruses that diffuse throughout the body which may cause any cell that the virus touches to become infected. During cell to cell transmission, a virus spreads to a neighboring cell through an intercellular transfer. While previous research has investigated viruses based on free cell transmission, few models have incorporated cell to cell transmission leading to unclear results and bias to certain variables. This research accounts for both free cell and cell to cell transmission, using an agent-based framework. The model represents virus infection and spread in a two-dimensional layer of cells in order to generate total virus over time graphs for corresponding initial dose of virus.
PHYS2019HASAN44461 PHYS
Type: Graduate
Author(s):
Md Tanvir Hasan
Physics & Astronomy
Roberto Gonzalez-Rodriguez
Physics & Astronomy
Conor Ryan
Physics & Astronomy
Advisor(s):
Anton Naumov
Physics & Astronomy
Location: Session: 1; Basement; Table Number: 2
(Presentation is private)In this work, a simple/scalable microwave-facilitated hydrothermal route is used to produce nitrogen self-doped graphene quantum dots (NGQDs) from a sole glucosamine precursor. These NGQDs with average sizes of ~6nm show bright/stable fluorescence both in the visible and near-IR. The structural and optical properties of as-prepared NGQDs are further altered to provide control for optoelectronic applications by using ozone and thermal treatment. Thermal processing serves as controllable avenues to decrease GQD emission via anticipated reduction processes. Oxidative ozone treatment results in the decrease of GQD average size down to 5.23 nm and a more disordered structure due to the introduction of the new functional groups. Structural and optical characterization was performed utilizing TEM, AFM, SEM microscopy and FTIR, EDX, Raman, fluorescence, absorbance spectroscopy. FTIR, EDX and Raman data suggest that this processing introduces oxygen-containing functional groups, enhancing the atomic percentage of oxygen and increasing ID/IG ratio. Ozone treatment shows enhancement of visible emission which is observed from 0 to 16 min ozone processing with following over oxidation-induced defect-related quenching. On the other hand, a progressive increase in defect-related NIR emission is observed up to 45 min. Such alteration of optoelectronic properties enhances NGQD performance in photovoltaic devices.
Untreated NGQDs (Un-NGQDs) and ozone-treated NGQDs (Oz-NGQDs) are utilized as a photoactive layer to fabricate a variety of solar cells. Although devices with untreated NGQDs show performances similar to existing reports, Oz-NGQDs exhibit significant improvement (~six fold) with maximum PCE of 2.64%, an open circuit voltage of ~0.83V, a short circuit current density of 4.8 mA/cm^2, and an excellent fill factor of ~86.4%. This enhancement can be potentially attributed to the increased/broadened visible absorption feature in device state due to the efficient charge transfer between the hole-blocking layer of TiO2 and Oz-NGQD having enhanced concentration of functional groups. This work suggests ozone treatment as an easy and powerful technique to alter the optoelectronic properties of versatile and scalably produced NGQDs which can be successfully utilized as an eco-friendly photoactive layer to boost the photovoltaic performance of solar cells.
PHYS2019HUEYYOU48564 PHYS
Type: Graduate
Author(s):
Carson Huey-You
Physics & Astronomy
Advisor(s):
Magnus Rittby
Physics & Astronomy
Location: Session: 1; Basement; Table Number: 7
View PresentationQuantum mechanical oscillations of a many-body system about a local potential minimum can in a first approximation be modeled by a set of harmonic oscillators about a local potential minimum. In more sophisticated models one also has to consider anharmonic effects.
Here we present the first steps towards a systematic solution of ground and excited state energies for a set of coupled quartic oscillators using coupled cluster techniques. We present the general approach of the equation of motion coupled cluster (EOM-CC) method. We give illustrative details of the diagrammatic approach to obtaining our operating equations as well as the resulting EOM-CC equations for a simple system of coupled harmonic oscillators perturbed by a quadratic perturbation. We point to the connection with Bogoliubov transformations and finally we illustrate the numerical behavior of the EOM-CC non-linear iterations and matrix diagonalization of our effective Hamiltonian obtained with our Python code.
PHYS2019JHA46123 PHYS
Type: Undergraduate
Author(s):
Rashmi Jha
Physics & Astronomy
Advisor(s):
Hana Dobrovolny
Physics & Astronomy
Location: Session: 2; 2nd Floor; Table Number: 5
View PresentationRespiratory syncytial virus, or RSV, is a virus that commonly causes lower respiratory tract infections throughout childhood and infancy. Most people who contract the virus recover within a short period of time, but it can cause respiratory illness, hospitalization, and even death within infants and the elderly. Agents that can effectively combat RSV are still not available for widespread clinical use, but one of the targets being investigated is PC786, a novel inhaled L-protein polymerase inhibitor. Using data from previous publications, we created models of the relationship between volume of PC786 and viral load in patients with RSV to try to determine how to best model the action of this drug.
PHYS2019LEE28437 PHYS
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
View PresentationWith 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.
PHYS2019MCCARTHY57534 PHYS
Type: Undergraduate
Author(s):
Gabriel McCarthy
Physics & Astronomy
Advisor(s):
Hana Dobrovolny
Physics & Astronomy
Location: Session: 2; 2nd Floor; Table Number: 6
View PresentationWe 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.
PHYS2019MCKINNEY32467 PHYS
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
View PresentationNon-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.
PHYS2019MURPHY60207 PHYS
Type: Graduate
Author(s):
Hope Murphy
Physics & Astronomy
Advisor(s):
Hana Dobrovolny
Physics & Astronomy
Location: Session: 1; Basement; Table Number: 1
View PresentationIn 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.
PHYS2019PHO52926 PHYS
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 is private)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.
PHYS2019RAY53904 PHYS
Type: Graduate
Author(s):
Amy Ray
Physics & Astronomy
Advisor(s):
Peter Frinchaboy
Physics & Astronomy
Location: Session: 1; 3rd Floor; Table Number: 1
View PresentationStar 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.
PHYS2019REEKS46081 PHYS
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
View PresentationAntimicrobial 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.
PHYS2019REEKS6818 PHYS
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
View PresentationPolysulfone 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.
PHYS2019RYAN42727 PHYS
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
View PresentationHigh-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.
PHYS2019STONE31461 PHYS
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 is private)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.
PHYS2019SUN49284 PHYS
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
View PresentationThe 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.
PHYS2019WEERASOORIYA61969 PHYS
Type: Graduate
Author(s):
Sachithra Weerasooriya
Physics & Astronomy
Advisor(s):
Mia Bovill
Physics & Astronomy
Location: Session: 2; 3rd Floor; Table Number: 10
View PresentationLarge 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.
PSYC2019AVELAR29440 PSYC
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
View PresentationTerror 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.
PSYC2019BENTLEY40614 PSYC
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
View PresentationFrom 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.
PSYC2019DUKES19806 PSYC
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
View PresentationHow 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.
PSYC2019GUARINO44570 PSYC
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
View PresentationThe 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.
PSYC2019GUYTON22707 PSYC
Type: Undergraduate
Author(s):
Nathan Guyton
Psychology
Vishal Thakkar
Psychology
Advisor(s):
Timothy Barth
Psychology
Location: Session: 2; 2nd Floor; Table Number: 6
View PresentationMoral 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.
PSYC2019HAYES32319 PSYC
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
View PresentationPast 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.