Author(s): April Horton Physics & Astronomy Francie Cashman Physics & Astronomy Andrew Fox Physics & Astronomy Suraj Poudel Physics & Astronomy Jo Vazquez Physics & Astronomy
Advisor(s): Kat Barger Physics & Astronomy
When massive stars in a galaxy die, they explode and create clouds of gaseous debris. If these clouds of debris break out of the galaxy, they can create galactic winds. The nearby Large Magellanic Cloud (LMC) galaxy is ideal for studying galactic winds as it is oriented face-on and is driving out 85 million Sun’s worth of gas. Using observations from the Hubble Space Telescope, we are studying chemical absorption fingerprints from the light that passes through the LMC’s galactic winds. These chemical fingerprints enable us to assess the physical properties of the winds. We are using the light from 150 young, massive stars in the LMC to probe through the LMC’s galactic winds. In order to determine where the LMC’s disk ends and the winds begin, we utilize the Galactic All-Sky Survey observations to trace the motions of the neutral hydrogen gas. Together, these observations will allow us to measure how fast the winds are moving, how much gas they contain, and their ionization states. Exploring the LMC’s galactic outflows will contribute to our understanding of the relationship between a galaxy’s environment and its evolutionary progression.
Author(s): Dustin Johnson Physics & Astronomy Alexander Caron Biology Rishi Manihar Physics & Astronomy John Reeks Physics & Astronomy
Advisor(s): Yuri Strzhemechny Physics & Astronomy Shauna McGillivray Biology
The antimicrobial properties of ZnO are well documented. Demonstrated effectiveness against various strains of both Gram-positive and Gram-negative bacteria in addition to being an abundant and inexpensive material leave it well positioned for application as an antibacterial agent. ZnO based antibacterial agents see current usage in biomedical, water treatment, food storage and various other industries. Despite the significant promise and proven application, realization of both novel and efficient, targeted applications is hindered by a lack of understanding in the fundamental mechanisms responsible for the antimicrobial properties of ZnO. In particular the role and nature of components of the local bacterial environment in mediating/hindering these antibacterial interactions. Phosphate-rich environments in particular have been observed to inhibit antimicrobial behavior in ZnO though the manner in which this occurs has not been adequately described. To elucidate the environmental interactions relevant to the antimicrobial action of ZnO we investigated the effects of interactions with both bacteria and the bacterial environments on the physicochemical and optoelectronic properties of the free crystalline surface of ZnO microparticles (MPs). This involves exposing hydrothermally grown ZnO MPs to phosphate-buffered saline (PBS) media both with and without the presence of Newman strain S. aureus bacteria. Changes in the surface electronic structure and charge dynamics due to these exposures are monitored via both time and energy dependent surface photovoltage (SPV) conducted prior to and following biological assays. In doing so we demonstrate significant changes in the characteristic timescales of long-lived processes in the SPV transients after exposure to phosphate-rich environments. Such findings point to significant phosphate adsorption at the free crystalline surface. This is further supported by suppression of oxygen rich defect centers after exposure to PBS media. We also comment on the interaction of bacteria as the presence of S. aureus suppresses this adsorption and influences charge transfer processes at short and intermediate timescales.
Author(s): Emma Alexander Physics & Astronomy Luca Ceresa Physics & Astronomy Jose Chavez Physics & Astronomy Ignacy Gryczynski Physics & Astronomy Joe Kimball Physics & Astronomy Michael Seung Physics & Astronomy
Advisor(s): Zygmunt Gryczynski Physics & Astronomy
Excitation and emission (observation) conditions heavily impact fluorescence measurements. Both observed spectra and intensity decay (fluorescence lifetimes), when incorrectly measured, may lead to incorrect data interpretations. The necessity of using so-called total fluorescence intensity or intensity measured under magic angle (MA) conditions is demonstrated for both steady-state and time-resolved fluorescence measurements. Rhodamine 6G (R6G) in two solvents - ethanol and glycerol have been used in order to demonstrate the general importance of Magic Angle observation.
Author(s): Gabriel McCarthy Physics & Astronomy
Advisor(s): Hana Dobrovolny Physics & Astronomy
The SARS-CoV-2 pandemic initially made landfall in the United States in early 2020, and at that point in the pandemic, few developed treatments left the initial prevention of the disease largely up to preventative measures like mask mandates, quarantines for infected individuals, and social distancing policies. As a result, we must understand how preventative measures affect the transmission of infectious diseases to prepare us to fight the future spread of similar diseases. To accomplish this, we used a SEIR model with a variable transmission rate and fit SARS-CoV-2 case data to it. Principally, we used four models for the change in transmission rate: instant, linear, exponential, and logistic. Then using these models for the decay of transmission rate, we obtained SSR and parameter values that allowed us to compare models for each state. After comparing models between the four states we fit, there was no evident best-fit model for the decay in transmission. These results may suggest that regional differences like behavior, socioeconomic status, and exact preventative measures enforced could be responsible for the disparity in how the transmission rate decayed.
Author(s): Natalie Myers Physics & Astronomy John Donor Physics & Astronomy Taylor Spoo Physics & Astronomy
Advisor(s): Peter Frinchaboy Physics & Astronomy
Star clusters have long been used as chemical and dynamical tracers for our home galaxy, the Milky Way. Many of these clusters are the old, metal poor, and massive objects known as globular clusters. These globular clusters are ideal test-beds for studying stellar evolution, stellar dynamics, and Galactic evolution since all the included stars are born from the same gas cloud. In this work, we combine the positions and motions of stars on the sky, provided by the European Space Agency’s Gaia space telescope, with the high-resolution chemical abundances from the Apache Point Galactic Evolution Experiment (APOGEE) to create a catalog of globular clusters. By only using data from two sources this sample of clusters is less susceptible to systematic offsets induced by combining multiple literature datasets. Overall, our catalog includes nearly half of all known Milky Way globular clusters, and a total of 5000 likely stellar members with APOGEE chemical abundances. We use these data to explore the internal properties of globular clusters as well as the population of the clusters as a whole to paint a picture of what the Milky Way looked like when it was first forming.
Author(s): Jonah Otto Physics & Astronomy Sarah Loebman Physics & Astronomy
Advisor(s): Peter Frinchaboy Physics & Astronomy
Large galaxy simulations offer an avenue to investigate observed properties of star clusters and classify them according to their shape in a controlled, known environment. In this work, we present a machine learning (ML) algorithm applied to images of simulated Milky Way-like galaxies from the FIRE-2 galaxy simulations. This set of galaxy simulations are able to show individual star clusters in Milky Way-like galaxies at “present day”, with cluster masses as small as ~40,000 solar masses. The spatial resolution within the galactic disks provides new opportunities to explore how star clusters can be identified. In this study, we compare human-classification with ML-classification of star clusters in these simulations. Recent advances in synthetic imaging allow for mock Hubble Space Telescope images to be produced across a large range of wavelengths. Here, we present first results comparing the classifications determined by humans with the performance of the ML algorithm developed for this project. We discuss how the lack of ability to resolve the smallest features of the galaxy in these images affects the performance of the ML algorithm as well as how to improve the accuracy of the classifications, relative to human performance.
Author(s): Hope Sage Physics & Astronomy
Advisor(s): Dr. Hana Dobrovolny Physics & Astronomy
The most common immunological models for analyzing viral infections assume even spatial distribution between virus particles and healthy target cells. However, throughout an infection, the spatial distribution of virus and cells changes. Initially, virus and infected cells are localized so that a target cell in an area with lower virus presence will be less likely to be infected than a cell close to a location of viral production. A density-dependent rate has the potential to improve models that treat cellular infection probability as constant. A Beddington-DeAngelis model was used to understand how density dependent parameters could impact the severity of an influenza infection. Parameter values were varied to understand implications of density constraints. For low density dependence, a steeper increase in number of virus and greater viral peak was predicted. Higher density dependence predicted a longer time to viral load maximum and a greater infection duration. Initial localization of infected cells likely slows the progression of infection. The model demonstrates that accounting for density dependence when analyzing influenza infection severity can result in an altered expectation for viral progression. A density-dependent infection rate may provide a more complete view of the interaction between infected and healthy cells.
Author(s): Manya Sharma Physics & Astronomy
Advisor(s): Hana Dobrovolny Physics & Astronomy
Mathematical models of cancer cells can be used by researchers to study the use of oncolytic viruses to treat tumors. With these models, we are able to help predict the viral characteristics needed in order for a virus to effectively kill a tumor. Our approach uses non-cancerous cells in addition to the tumor to determine when the virus will spread to non-cancerous cells. However, there are several models used to describe cancer growth, including the exponential, Mendelsohn, logistic, linear, surface, Gompertz, and Bertalanffy. We study how the choice of a particular model affects the predicted outcome of treatment.
Author(s): Iver Sneva Physics & Astronomy Mia Bovill Physics & Astronomy Sachi Weerasooriya Physics & Astronomy
Advisor(s): Mia Bovill Physics & Astronomy
Galaxies are giant playgrounds in which stars, planets, and potentially sentient carbon-based lifeforms live out their lives. We live in the Milky Way galaxy, however, like all larger galaxies the Milky Way has a slight cannibalism problem. Larger, more massive galaxies are assembled from smaller galaxies where the surviving small galaxies are dwarf galaxies. The latest victims of our Milky Way’s cannibalism are the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), and we have no idea what happened to their dwarf galaxies. To further complicate things, we don’t know how many dwarf galaxies fell into the Milky Way with the LMC, or where they ended up. In addition, the dwarf satellites of the LMC should be extremely faint and difficult to detect. We use computer simulations in order to take a bite out of these questions. We send a perfectly innocent LMC and its satellites into the gravitational potential of a Milky Way galaxy, and see where the dwarf satellites are flung.
Author(s): Taylor Spoo Physics & Astronomy
Advisor(s): Peter Frinchaboy Physics & Astronomy
Astronomers determine chemical abundances of stars through spectroscopy, which provides clues as to where the stars were formed. We use the chemical composition of stars to infer their relative ages due to past enrichment. However, the surface abundance of stars is not always constant during its life and will change as the star evolves due to its internal processes. As a result, if we assume the chemical makeup of stars is constant within a star cluster, it can cause systematic errors when inferring stellar parameters. For example, in previous investigations, the star cluster M67 has been observed to have signatures of atomic diffusion: the combined effect of gravity pulling elements deeper into the star and radiation preventing elements from floating to the surface locks elements below the observable surface of a star which cannot be unlocked until the star evolves further, changing the measured abundance. When the star evolves, convection reaches into the interior of the star and carries these elements back to the surface where they can now be observed once again. This process can explain the elemental abundance variation found in main-sequence stars, like our Sun, and also evolving stars, which can also affect what apparent age we determine. Stars within a cluster tend to form from the same gas cloud at the same time, giving them the same age and initial chemical composition. Therefore, star clusters are ideal test-beds for investigating elemental abundance and the resulting apparent age variations. Data from the Apache Point Galactic Evolution Experiment survey provides the opportunity to investigate how abundance variation/diffusion is affected by age.
Author(s): Sahana Talwar Physics & Astronomy
Advisor(s): Hana Dobrovolny Physics & Astronomy
Abstract: Researchers hypothesize that the initial amount of virus will affect the severity of the disease. They also believe that this will affect the amount of antivirals needed. We used mathematical modeling to study the effect of the initial viral dose on the effectiveness of antivirals. We simulated Sars-Cov-2 infections starting with different amounts of virus and treated with different amounts of antivirals, then measured the duration of the infection. This mathematical model predicts little to no effect on the amount of antivirals needed when the starting dose of virus is changed.
Author(s): Ugur Can Topkiran Physics & Astronomy Anton Naumov Physics & Astronomy Alina Valimukhametova Physics & Astronomy
Advisor(s): Anton Naumov Physics & Astronomy
With novel materials getting smaller and their size falling to the nanometer scale, it becomes harder to fully characterize them by only using the experimental apparatus at hand. Therefore, taking advantage of computational methods proves to be trustworthy in filling those gaps and in aiding our experimental data to get a better understanding of the nanomaterials’ structural and electronic properties. Graphene quantum dots (GQDs) have recently become one of the flagships of carbon nanotechnology due to their remarkable physical properties and, when functionalized, their ability to become water soluble, biocompatible, and capable of fluorescence in the visible and near-infrared. This makes them perspective carriers for therapeutic delivery and image-tracking. In order to assess the advantages of their utilization for a variety of bioapplications, we have investigated the optical properties of doped GQDs and their interactions with biomolecules using a variety of molecular simulation approaches. The true atomic ground state of the N-GQD is achieved by performing first-principle calculations based on density functional theory (DFT). DFT calculations also unrevealed the contributions of each functional group within the structure to HOMO–LUMO band edges. The adsorption of biomolecules and genes on the GQD surface has been further investigated with regard to the GQD structure, complementing experimental results that verify gene and drug complexation.
Author(s): Alina Valimukhametova Physics & Astronomy Roberto Gonzalez-Rodriguez Chemistry & Biochemistry Klara Gries Physics & Astronomy Bong Han Lee Physics & Astronomy Ugur C. Topkiran Physics & Astronomy
Advisor(s): Anton Naumov Physics & Astronomy Giridhar Akkaraju Biology Jeffery Coffer Chemistry & Biochemistry
While silencing RNA (siRNA) technology has become a powerful tool that can enable cancer-specific gene therapy, its translation to the clinic is still hampered by several critical factors. These include the inability of cell transfection by the genes alone, poor siRNA stability in blood, and the lack of delivery tracking capabilities. Recently, graphene quantum dots (GQDs) have emerged as a novel platform allowing targeted drug delivery and fluorescence image-tracking in the visible and near-infrared. These capabilities can aid in overcoming primary obstacles to siRNA therapeutics. Here, for the first time, we utilize biocompatible nitrogen and neodymium-doped graphene quantum dots (NGQDs and Nd-NGQDs) for the delivery of Kirsten rat sarcoma virus (KRAS) and epidermal growth factor receptor (EGFR) siRNA effective against a variety of cancer types. The non-covalent loading of siRNA onto GQDs is evaluated and optimized by the electrophoretic mobility shift assay and zeta potential measurements. GQDs as a delivery platform facilitate successful gene transfection into HeLa cells confirmed by confocal fluorescence microscopy at biocompatible GQD concentrations of 375 µg/mL. While the NGQD platform provides visible fluorescence tracking, Nd doping enables deeper tissue near-infrared fluorescence imaging suitable for both in vitro and in vivo applications. The therapeutic efficacy of the GQDs/siRNA complex is verified by successful protein knockdown in HeLa cells at nanomolar siEGFR and siKRAS concentrations. A range of GQDs/siRNA loading ratios and payloads is tested to ultimately provide substantial inhibition of protein expression down to 31-45% comparable with conventional Lipofectamine-mediated delivery. This demonstrates the promising potential of GQDs for the non-toxic delivery of siRNA and genes in general, complemented by multiwavelength image-tracking.
Author(s): Jo Vazquez Physics & Astronomy Kat Barger Physics & Astronomy Alice Blake Physics & Astronomy Andrew Fox Physics & Astronomy Jaq Hernandez Physics & Astronomy Jay Lockman Physics & Astronomy Matthew Nuss Physics & Astronomy Bart Wakker Physics & Astronomy
Advisor(s): Kat Barger Physics & Astronomy
In order for galaxies to sustain current star-formation rates, including our Milky Way, they need to replenish their reservoirs of gas. High-velocity clouds (HVCs) entering our galaxy, like the Smith Cloud, present a possible source of gas for future star formation. Although the chemistry of the Smith Cloud has been previously studied, it is unclear whether there is variation in the chemistry of the Smith Cloud. With the Hubble Space Telescope, we measure the absorption of various elements along the tail and an adjacent fragment of the Smith Cloud. For the tail, we used existing observations, and for the fragments, we observed two new sightlines with Hubble. We additionally use radio emission-line observations from the Green Bank Telescope and from the Galactic All-Sky Survey (GASS) to understand the neutral hydrogen gas. Using observations in conjunction with the Cloudy simulations, we provide constraints on the chemistry of all five sightlines. Our new sulfur abundances for the adjacent fragment of the Cloud are higher than those downstream in the trailing wake. By quantifying the properties of gas clouds traveling through the Galactic halo, we can assess how they are impacted by their environments and better understand how the star-formation gas reservoirs of large galaxies are replenished.
Author(s): Alessa Wiggins Physics & Astronomy Sarah Loebman Physics & Astronomy Jonah Otto Physics & Astronomy
Advisor(s): Peter Frinchaboy Physics & Astronomy
There is currently a mismatch between the chemical properties of a typical star and those within star clusters across the Milky Way galaxy. Star clusters are groups of stars bound by gravity, many of which are found in the disk of the Milky Way. Studying these star clusters reveals essential information about the rich history of our Galaxy, as we can measure their age and their chemical composition independently. While some clusters interact with their environment, causing them to dissolve, other clusters remain bound for billions of years. In order to investigate these disruption events, we will study the evolution of star clusters throughout cosmic time via simulations. With the use of cosmological simulations, such as the Feedback In Realistic Environment (FIRE) simulation, we are able to learn why clusters move from their original place of formation and how far they go. Additionally, FIRE allows us to trace star clusters through their different stages of their evolution, and study how they survive as they interact with other components of the galaxy. In this study, we will investigate the Galactic chemical gradient mismatch for the Milky Way, as we compare the FIRE simulations to the observed star cluster distribution and properties measured from Gaia satellite and the Sloan Digital Sky Survey.
Author(s): Ashley Berdelis Psychology
Advisor(s): Sarah Tauber Psychology
Title: Saving Important Material: An Examination of Offloading, Memory, and Metacognition.
Authors: Ashley J. Berdelis, Morgan D. Shumaker, Sarah K. Tauber
Cognitive offloading—externally storing information to reduce internal cognitive load (e.g., on a smartphone)—has become widespread with technological advances (Risko & Dunn, 2015). Often, offloading is used when we need to remember information in the future (e.g., setting calendar reminders). However, sometimes how much to-be-remembered material we can offload is constrained by time or by available storage space. The agenda-based regulation (ABR) framework posits that learners assess task constraints prior to study and construct agendas to achieve the task goal within these constraints (Ariel & Dunlosky, 2009; 2013). For instance, learners allocate more study time to and selectively study more important (high-value) over less important (low-value) material, allowing them to maximize test performance under such constraints (Soderstrom & McCabe, 2011; Middlebrooks & Castel, 2018). Thus, learners might adopt similar offloading strategies by offloading important material and using internal memory for unimportant material. Critically, people often engage in offloading with the expectation that their external store will be available to them at the time of need; however, this is not always the case (e.g., technology failing). When offloaded material is available at the time of need, memory for that material is enhanced (Park et al., 2022). When offloaded material is unavailable at the time of need, memory for offloaded material suffers compared to memory for internally stored (recalled) material (Park et al., 2022). To use external tools most effectively, it may be useful for learners to be aware of their ability to remember externally and internally stored material. Thus, the current study examined whether learners are aware of their ability to later remember offloaded and internally stored material. Participants completed a series of memory tasks with the option to offload only a portion of the to-be-remembered items. Before the study phase in each task, participants made judgments about how much of the offloaded and recalled items they could later identify as having been seen before. After the study phase, participants made similar post-task judgements and were given a surprise recognition test on the studied material, during which the external store was unavailable.
We also examined whether learners could transfer their metacognitive awareness from one task to another, as offloading is relevant to various life scenarios. Finally, we examined how the value of the to-be-remembered material influences offloading, and how offloading and recall influence later memory. Participants’ pre-task judgements on the first task indicated that they would recognize more offloaded items than recalled items. However, this difference was not present on tasks two and three, suggesting that participants used experience with the first task to update their judgments for offloaded items. Participants offloaded more high-value than low-value items and had better recognition memory for recalled items than offloaded items, in all three tasks. Overall, people strategically offload important over unimportant material, but memory for offloaded material suffers compared to memory for recalled material. Learning about the relationships between value, offloading, memory, and metacognition can allow us to use external storage devices more effectively.
Author(s): Paige Braden Kuhle Psychology Kelly Brice Psychology Paige Dean Biology Miranda Jelenik Biology Vivienne Lacy Biology Catherine Shoffner Biology Buse Uras Psychology
Advisor(s): Gary Boehm Psychology Michael Chumley Biology
Approximately 72% of Americans are overweight or obese, and healthcare for obesity-induced chronic diseases accounts for almost half of the total costs for disease treatment in the U.S. Further, obesity is a key risk factor for Alzheimer’s disease (AD), a fatal disease that is the 6th leading causes of death in the U.S. As obesity and AD are comorbid, dietary intervention could be a key strategy to reduce excessive weight gain and AD risk.
High obesity prevalence in the U.S. is most likely due to the typical American diet, known as the Western Diet (WD), which is comprised of simple carbohydrates, refined sugars and vegetable oils, processed meat, and high-fat dairy products. Conversely, the Mediterranean Diet (MD), a plant-based diet, is typically comprised of complex carbohydrates, fruits, vegetables, olive oil, seafood, and low-fat dairy products. The MD has been shown to reduce the risk of developing chronic diseases, and thus, has the potential to protect against AD.
The current study examined the effects of the MD and WD, modeled after typical human diets, in a hippocampus dependent learning task in wildtype mice. As the hippocampus is a crucial brain region for learning and memory, and hardest hit by AD pathologies, we aimed to explore how diet affects learning and memory processes that are dependent on this brain region. The results revealed that life-long consumption of the MD enhanced spatial learning and memory, in comparison to the WD, in male mice. These results suggest that long-term consumption of the MD could be used to enhance cognition in older adults.
Author(s): Kelly Brice Psychology Gary Boehm Psychology Paige Braden-Kuhle Psychology Michael Chumley Biology Vivienne Lacy Biology Chelsy Mani Biology Allison Regan Biology
Advisor(s): Gary Boehm Psychology Michael Chumley Biology
Healthy sleep is imperative for many biological and psychological functions, including immune function and neural plasticity. Alarmingly, over one-third of US adults report getting less than the minimum recommended 7 hours of sleep each night. Unfortunately, sleep loss is linked with impairments in immune and cognitive function. Our lab previously demonstrated that chronic sleep restriction (CSR) is associated with cognitive impairment in wild-type mice. The present research investigated the impact of CSR on markers of inflammation and neural plasticity in response to an immune insult in adult C57BL/6 mice. Male and female mice underwent six weeks of CSR, followed by one intraperitoneal injection of lipopolysaccharide (LPS) or saline. Four hours post-injection, serum and hippocampal tissue were collected for brain-derived neurotrophic factor (BDNF) and cytokine analysis. Results revealed patterns that differed between males and females. Male mice that underwent CSR and received LPS had increased serum pro- and anti-inflammatory cytokines, while cytokine mRNA in the hippocampus was decreased compared to control mice that received LPS. Conversely, female mice that underwent CSR and received LPS had decreased pro-inflammatory cytokines in both the serum and hippocampus compared to control mice that received LPS. Moreover, males that underwent CSR exhibited decreased hippocampal BDNF mRNA compared to controls, while this difference was not observed in females. These patterns of findings suggest a complicated interaction between chronic sleep loss, immune function, and sex, underscoring the necessity to understand how lifestyle factors such as sleep loss can influence immune and cognitive dysfunction in both men and women.
Author(s): Zoey Chidiac Psychology Matthew Espinosa Psychology
Advisor(s): Sarah Hill Psychology
The introduction of the birth control pill allowed women to express greater control over their fertility. Since then, men have had less responsibility when it comes to family planning, as the majority of birth control technologies have been directed toward women, thereby creating an implicit association between femininity and the use of birth control. Currently, male birth control is in various stages of research, and when one becomes available, this association may decrease men’s willingness to use this contraceptive. Indeed, previous research has shown that men’s lower willingness to use a male birth control is associated with a desire to avoid appearing feminine. Therefore, increasing the association between masculinity and birth control could increase men’s willingness and interest in using a male birth control. The present study aimed to examine whether the degree to which a male birth control is associated with masculinity in an advertisement (ad) will influence men’s willingness to, and interest in, using the birth control. I predicted that the stronger the ad associated male birth control with masculinity, the more that men would be willing to/have an interest in using the depicted birth control. Participants viewed one of two ads for a male birth control, either a masculine ad or a non-masculine ad, and then indicated their willingness and interest in using the depicted birth control. We also measured men’s self-reported openness to short-term, uncommitted sexual relationships. Results suggested that similar willingness and interest in using the birth control was reported between the masculine ad and the non-masculine ad, suggesting that men’s willingness/interest was not influenced by the masculinity of the ad. However, the results did reveal a moderating effect of men’s sexually unrestricted desires. More specifically, when men viewed the non-masculine ad, there was no association between men’s willingness to use the depicted male birth control and their desires for short term, uncommitted sex. However, among the men who viewed the masculine ad, the more they desired short-term, uncommitted sexual relationships, the more willing they were to use the advertised birth control. Overall, these findings suggest when men are motivated to pursue short-term, uncommitted sex, they are then more willing to use a male birth control if that birth control is associated with masculinity. The implications of these findings for research on family planning will be discussed.
Author(s): Kennadi Cook Psychology Addison Babineau Psychology
Advisor(s): Uma Tauber Psychology
Retrieval practice typically improves learning and memory performance of basic information (Rowland, 2014). Much less research has evaluated the degree to which retrieval practice results in better test performance of more complex information such as category learning. In one case, retrieval practice led to superior classification performance relative to restudy conditions (Jacoby et al., 2013); however, in another, it did not (Babineau et al., in press). One important component that may contribute to retrieval practice effects in category learning is whether the learning process is self-regulated. We systematically explored this issue with the goal to establish when retrieval practice benefits learning of complex categorical information. During the experiment, we manipulated the study strategy (Retrieval practice versus Study) and the learning context (Experimenter-controlled versus Self-regulated) between-participants during a complex category learning task. Specifically, participants learned to classify six categories of organic chemistry compounds. For participants in the retrieval practice groups, participants practiced classifying each exemplar into the correct category and received corrective feedback after each trial. Participants in the study groups did not complete practice test trials. Instead, they studied all exemplars without practicing category classification nor did they get feedback on their learning. For participants in the experimenter-controlled groups, the order of the trials was fixed in an interleaved order. However, participants in the self-regulated groups made decisions about what to study after each trial. They were able to study a compound of the same type, a compound of a different type, or proceed to the test (after viewing 72 exemplars. After the study phase concluded, participants completed two classification tests. During the novel classification test, participants classified new exemplars they had never seen from the six chemical categories they just studied. During the studied exemplar test, participants classified the exemplars they had previously studied. The results revealed that participants who completed retrieval practice trials during the study phase performed better on the novel and studied classification tests than did participants who completed study trials. The benefit of practice testing on complex category learning was maintained for participants who self-regulated their learning and for participants whose learning was experimenter-controlled. The results of the present research support the use of retrieval practice as an effective study strategy for complex categorical information. Further, retrieval practice improved classification performance for those who self-regulated their category learning. Students often self-regulate their learning of complex information, and these novel findings indicate that completing a practice test improves student learning in controlled environments like the classroom, as well as in student-controlled environments such as studying outside of the classroom.
Author(s): Morgen Crosby Psychology Christopher Hagen Psychology Pedro Ogallar Psychology Francesca Vignolo Psychology
Advisor(s): Mauricio Papini Psychology
Frustration is a complex emotional state that occurs when reward expectations are violated. In animals, this can involve a variety of different types of rewards such as food, shelter, or access to mates. When an animal learns to expect a certain reward and that reward is of lesser quality or quantity than expected, the animal will reject the reward and experience a bout of negative emotion known as frustration. This behavior is often modeled in the lab in a paradigm known as consummatory successive negative contrast (cSNC) and involves training rats to expect a high value sucrose solution (32%) and then downshifting them to a lower value sucrose solution (2%). As a result of this downshift, consummatory behavior is shown to be suppressed beyond that of unshifted controls. To better understand the brain circuitry behind this response, neural activity of several key brain areas was assessed after a 32-2% sucrose downshift with additional 32-32% and 2-2% controls using immunohistochemistry. More specifically, the protein c-Fos, which is expressed in recently depolarized neurons and can therefore act as a proxy for neural activity, was quantified in brain areas relating to reward processing, emotion regulation, and action coordination. The results show several areas that are activated and correlate with one another during downshift. These data provide the groundwork for establishing a connectome of brain areas that are activated during cSNC and are essential to frustration.
Author(s): Jordan Crupper Psychology
Advisor(s): Tracy Centanni Psychology
As our world is becoming more globally connected, the ability to speak another language is increasingly becoming a valuable skill. While there are training programs to help acquire a new novel language, this task becomes increasingly difficult with age– thus presenting the need for a novel method of intervention to assist in this process. Considering this increasing difficulty, a new biologically based intervention could be valuable for improving learning and memory. Previous research conducted in our lab has shown that noninvasive transcutaneous auricular vagus nerve stimulation (taVNS) is an effective intervention in memory-based reading comprehension (Thakkar et al., 2023). TaVNS has also been shown to boost associative memory (Jacobs et al., 2015), spatial working memory (Sun et al., 2021), and emotional memory (Ventura-Bort et al., 2021). Despite this knowledge, little is known about taVNS and its effects on long-lasting language retention. Thus, this current study explores whether transcutaneous auricular vagus nerve stimulation can improve learning and retention of a new and novel language when paired with a training routine. Typically developing college-aged individuals were recruited through an online participant pool. All individuals were screened for age, IQ, reading, memory, and attention for inclusion in this study. The participants completed a one-hour training session in which they were presented with 30 Palauan nouns, the respective English translations, and images of the nouns. During this time, the participants received sham, 5 Hz, or 25 Hz stimulation to the posterior of the left tragus. Prior to training, participants completed a translation test to measure their knowledge of the Palauan language, and this test was repeated immediately after training and again seven days later to measure learning and retention. After analysis of the results, no effect was found for any stimulation group immediately after training. At retention, however, the 25 Hz taVNS group showed significantly greater performance than both the sham and 5 Hz taVNS groups. There was also no statistical difference between the performance of the sham and 5 Hz taVNS groups..These data suggest that taVNS may be used to help in the retention of novel words of a new language. The results further suggest that stimulation frequency may impact efficacy of the intervention. These data will be important for ongoing research examining the uses of taVNS, and its use as an intervention for learning and retention of a new language, and in other areas of cognition.
Author(s): Katja Cunningham Psychology
Advisor(s): Sarah Hill Psychology
Previous research finds that people are perceived as naïve and socially submissive when expressing fear. The outward expression of this emotion is thought to function to elicit prosocial responses from others. However, no work has examined whether fearful expressions are also perceived as an opportunity for exploitation in environments which favor opportunistic responding such as harsh, low resource environments. The current research was designed to examine 1) the perceived opportunities posed by fearful individuals, and 2) whether the presence of someone from a harsh environment leads individuals to suppress, rather than express, their fear. In two studies, participants were randomly assigned to evaluate the opportunities for exploitation posed by a person expressing either fear or no emotion. In a third study, participants were randomly assigned to view a fear inducing video from a horror movie or a neutral video from a nature documentary. Participants then disclosed to a bogus study partner (from a harsh or benign environment) the degree of fear they felt while watching the video. Results revealed that fearful individuals are perceived as posing more of an opportunity for exploitation than individuals expressing no emotion. Additionally, being in the presence of an individual from a harsh environment was associated with reduced fear expression after watching a scary video. These results suggest that the expression of fear may be risky under certain contexts.
Author(s): Jackie Ginsborg Psychology Beatrice Acione Psychology
Advisor(s): Cathy Cox Psychology
EXAMINING THE INTERACTIVE EFFECTS OF ATTACHMENT STYLE AND RELATIONSHIP NOSTALGIA ON RELATIONSHIP QUALITY
Nostalgia is a longing for past experiences, relationships and events. It has been observed that it is beneficial for romantic relationships. There is no prior research that has analyzed the interaction between attachment styles and nostalgic primes that are specific to relationships and how this interaction affects relationship quality. This study wanted to specifically focus on this gap. Firstly in Study 1, participants engaged in and completed a writing task that was centered around relationship nostalgia. The next two studies focused on the correlation between music and nostalgia. Study 2 results showed that highly avoidant and anxiously attached participants revealed lower partner commitment while listening to nostalgic songs compared to control songs. In the 3rd and last study, participants listened to nostalgic songs with their partner or alone, or listened to control songs with their partner. The results showed that both the nostalgia-together and nostalgia-alone situations resulted in similar relationship quality aftereffects. However, both of these conditions scored higher than the control-together condition, specifically when measuring certainty in relationships. All three studies propose that sentimental longing for the past, specifically with romantic relationships either through writing or listening to nostalgic music alone or with a partner, is a positive experience. The data does not apply to avoidantly attached individuals.
Author(s): Sarah Gonzalez Psychology Madison Brown Psychology Antonella Delgadillo Psychology Savannah Hastings Psychology Esmeralda Herrera Psychology Elizabeth Joseph Psychology Kevin Knight Psychology Kha Vu Psychology Amanda Wiese Psychology
Advisor(s): Amanda Wiese Psychology
Data suggests that the number of unplanned pregnancies is still high among college students. (Sutton & Walsh-Buhi, 2017). Socioeconomic status (SES) and racial/ethnic factors influence contraceptive usage, and lack of knowledge about contraception can lead to inconsistent use of birth control. Research suggests that contraceptive knowledge amongst college students is low or moderate (Carter et al., 2012). Using the Integrated Model of Behavioral Predictions (Sutton & Walsh-Buhi, 2017), the current study seeks to explore the impact of a person’s perceived SES on their attitudes toward contraceptive usage. Texas Christian University (TCU) students were recruited on campus (N = 50) and asked to complete a brief online survey via Qualtrics. We hypothesized that individuals who perceive themselves as having lower SES will have more negative attitudes towards utilizing contraceptives. Little evidence was found to support this hypothesized relationship. However, greater contraceptive knowledge was found to be associated with more positive contraceptive attitudes. These results should encourage efforts that increase contraceptive knowledge among college students, such as by creating opportunities for sexual health education.