Graphene quantum dots (GQDs) have emerged as a forerunner of carbon nano-biotechnology due to their multifunctional delivery and imaging capabilities as they exhibit fluorescence in the visible and near-infrared, high biocompatibility, and water solubility. These properties put GQDs forward as a compelling drug delivery platform that has already been utilized in a variety of applications including the delivery of chemotherapeutics, antibiotics as well as siRNA and CRISPR-based gene therapy. However, cellular entry pathways of this nanomaterial still remain largely undefined. In a number of studies describing GQD cellular internalization different and, often, conflicting results have been presented due to surveying only few endocytosis inhibitors and disregarding their potential off-target pathways. Understanding the cell internalization routes of GQDs is crucial while delivering drugs in different types of cell lines. Herein, we performed a holistic approach to cell uptake studies on GQDs of different charges by the comparative study of their preferred endocytosis paths in non-cancerous (HEK-293) and cancerous (HeLa) cell lines. The concentration and cell viability of GQDs were determined by MTT assays, while their endocytosis paths were investigated through confocal fluorescence microscopy on cells treated for up to 24 hours. The potential for GQD interactions with the cell membrane was also examined via zeta (ζ) potential measurements. Our findings provide insights into the internalization mechanisms of the GQDs into cell membranes of healthy and cancer cells. The optimization of these mechanisms can serve for the enhancement of a variety of novel GQD applications in biomedicine including therapeutic delivery, disease detection through sensing as well as diagnostic imaging.

Due to high tissue penetration depth and low autofluorescence backgrounds, near-infrared (NIR) fluorescence imaging has recently become an advantageous diagnostic technique used in a variety of fields. However, most of the NIR fluorophores do not have therapeutic delivery capabilities, exhibit low photostabilities, and raise toxicity concerns. To address these issues, we developed and tested five types of biocompatible graphene quantum dots (GQDs) exhibiting spectrally-separated fluorescence in the NIR range of 928–1053 nm with NIR excitation. Their optical properties in the NIR are attributed to either rare-earth metal dopants (Ho-NGQDs, Yb-NGQDs, Nd-NGQDs) or defect-states (nitrogen doped GQDS (NGQDs), reduced graphene oxides) as verified by Hartree-Fock calculations. Moderate up to 1.34% quantum yields of these GQDs are well-compensated by their remarkable >4 h photostability. At the biocompatible concentrations of up to 0.5–2 mg ml−1 GQDs successfully internalize into HEK-293 cells and enable in vitro imaging in the visible and NIR. Tested all together in HEK-293 cells five GQD types enable simultaneous multiplex imaging in the NIR-I and NIR-II shown for the first time in this work for GQD platforms. Substantial photostability, spectrally-separated NIR emission, and high biocompatibility of five GQD types developed here suggest their promising potential in multianalyte testing and multiwavelength bioimaging of combination therapies.

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. This enables us to investigate where open clusters form, if and why they move from their radius of formation, and how they traverse and interact with the Galaxy over time. In this work, we focus on tracing the unique trajectories of three illustrative open clusters throughout time. In the future, we aim to compare the FIRE-2 simulation results to the observed results from the SDSS-based Open Cluster Chemical Abundance and Mapping (OCCAM) survey.

Abstract
Research on non-verbal learning disordered (NVLD) children can lead to improvements or even overcome the learning difficulties and functional limitations the children experience. According to the latest measurement, the prevalence of non-verbal learning disorder (NVLD) is approximately 4% in the general population. 1 in 100 children in the United States have non-verbal learning disorder (NVLD), and 10 percent of the children of special learning disordered (SLD) populations are suffering from non-verbal learning disorder (NVLD). This disability is defined as a dysfunction of the brain’s right hemisphere functioning; this part of the brain processes nonverbal, performance-based information, including visual-spatial, organizational, and evaluative functions. Visual-motor control, dynamic balance, and bilateral coordination are also the most significant motor skill deficits in children with special learning disabilities (SLD). Participants (n = 20) with non-verbal learning disorder (NVLD) were randomly assigned to monoliteral and bilateral perceptual motor exercises (n = 10 per group). The children performed monolateral and bilateral perceptual motor exercises that were designed to improve neuropsychological profiles, manual dexterity, and visual-spatial performance measures. There was a significant difference in the average of right-hand dexterity, left-hand dexterity, and spatial memory after the intervention of monolateral and bilateral perceptual exercises (ps<.05). The study of using physical activity to enhance inter-hemispheric connection supports the hypothesis that there is right-hemisphere dysfunction in NVLD children. These results suggest integrating these interventions in educational and therapeutic settings would be helpful to children with NVLD and perhaps also for children with other learning disorders.

Cannabidiol (CBD) is derived from the Cannabis sativa plant and has been found to reduce anxiety-like behavior in rodents on an elevated plus maze (EPM) when injected, as well as in humans in both social anxiety and fear conditioning situations when consumed orally (Blessing et al., 2015). Pharmaceutical grade CBD is what is primarily used in research, but most people consume over-the-counter (OTC) CBD and there is a need to evaluate the benefits of its consumption (Chesney et al., 2020). In the current experiment, we explored the effectiveness of voluntary oral consumption of OTC CBD to reduce anxiety-like behaviors in rats using EPM and open field (OF) tests. Rats were given either 20 mg/kg of OTC CBD isolate or distilled water for 16 days prior to testing. On day 17, rats were placed on the EPM 2-hours after feeding for 5-minutes and on day 18, rats were placed on the OF in the same manner. The amount of time spent in the open vs. closed arms of the EPM and the center vs. outer portions of the OF was evaluated. If rats were less anxious (CBD group), then we expected that they would spend more time in the open arms of the EPM and center of the OF than the control group. The results will be discussed with respect to the grade of CBD, the administration route, and the type of test.

Decades of research finds a relationship between low socioeconomic status (SES) in childhood and poor health outcomes in adulthood. However, recent evidence suggests individuals who experience upward socioeconomic mobility exhibit poorer health than those who remain in low SES environments throughout their lives. The current work examined the relationship between physical health and psychological stressors associated with upward socioeconomic mobility (i.e., financial insecurity, obligation to family, social isolation, and threat hypervigilance). Participants provided information about their childhood, current, and expected future SES to make upward socioeconomic mobility salient among individuals with low childhood SES. Then, participants reported their perceived psychological stress. Physical health markers (i.e., hear rate, blood pressure, inflammatory cytokine release) were measured throughout the study to examine physiological stress responses to upward socioeconomic mobility. Results reveal that psychological stressors faced by those experiencing upward socioeconomic mobility are associated with physiological responses which may contribute to poor health outcomes.

Just as there are many ways for people to be socially connected to each other, there are just as many ways to be isolated. A novel focus of empirical research, existential isolation describes the perception that one is alone in their experience of the world; that no one shares your perspective or can come close to understanding it. Existing literature find that experiences of existential isolation are associated with a host of negative wellbeing outcome, such as increased feelings of loneliness, death thought accessibility, depression and anxiety symptoms, and reduced self-esteem. Similarly, though more thoroughly empirically examined, social exclusion too represents a socially isolating experience that threatens our psychological and physical wellbeing. While theoretically distinct in several meaningful ways, existential isolation is often found to be comorbid with the feelings of interpersonal isolation that are common among socially excluded individuals. As such, the present study aimed to empirically examine the wellbeing outcomes shared by experiences of existential isolation and social exclusion, so as to better understand the unique effects that existentially isolating experiences may have on personal wellbeing. Recruiting a sample of 186 adult online via Amazon Mechanical Turk (MTurk), participants were randomly assigned to write about either an experience in which they felt existentially isolated, in which they were socially excluded, or their morning routine (i.e., a neutral control), and then complete questionnaires assessing their mental wellbeing. Results showed that participants in the existential isolation and social exclusion conditions both felt greater loneliness, existentially isolation, negative emotion, and need threat compared to participants in the neutral control condition, but similar to each other. Further, those who recalled a social exclusion experience also reported feeling greater threat to each of their fundamental social needs than those who recalled an existentially isolating experience. Therefore, the present results suggest that, within the domains of cognitive wellbeing, existential isolation and social exclusion share many negative outcomes, but social exclusion more severely impacts our fundamental social needs. The implications of these findings for research aiming to understand the cognitive and health outcomes associated with socially isolating experiences will be discussed.

Language is crucial to understanding human cognition, as it allows for conceptualization, more abstract thinking, and enables far greater capability for problem-solving, conveying ideas, symbolic thinking, and numerous other advanced cognitive actions. Human speech is learned motor behavior, and as such requires preparatory motor behavior (e.g., preceding a long bout of speech, people will take a deep breath). Songbirds, like zebra finches, produce song that is remarkably similar physiologically and neurologically to human speech, and also requires preparatory motor behavior and respiration. Understanding the relationships between different parts of song allows for greater understanding of the nature of learned vocalization. Using a pressure transducer and a surgically implanted cannula, we monitored air pressure during zebra finch song. Final analyses will assess the relationships between introductory notes and the first syllable of song. The relationships between notes will provide further information on the purpose of introductory notes in song, which may in turn aid our understanding of motor and cognitive preparation for speech.

In a devaluation procedure, a primary reinforcer (e.g., food) is paired with an aversive outcome (e.g., illness), which results in a reduction of the response (e.g., a lever press) that previously led to the reinforcer. According to the hedonic shift hypothesis, reexposure to the reinforcer after devaluation is necessary to observe the devaluation effect (e.g., reduced responding). This prediction has been supported by findings with devaluation of a primary reinforcer, but also with devaluation of a stimulus (e.g., a light) paired with the primary reinforcer, known as a conditioned reinforcer (CDR). An elevation procedure involves pairing a low-value reinforcer with a high-value reinforcer. The current experiment examined whether devaluation or elevation of a CDR could occur with reexposure. Rats were trained to lever press for an audiovisual CDR previously paired with a low (sucrose) or high (chocolate-pellet) value reinforcer. During a single pairing, the CDR’s value was then either upshifted (sucrose → chocolate-pellet), downshifted (chocolate-pellet → sucrose), or unshifted (sucrose → sucrose) in separate groups. After CDR reexposure, all groups responded similarly, despite some receiving devaluation or elevation. The effectiveness of a CDR paired with a low value reinforcer, factors that influence the effectiveness of CDR training, and the challenges of a single-pairing procedure will be discussed.

Individuals that experience multiple forms of traumatic events are more susceptible to a number of negative outcomes including, but not limited to, delinquency and difficulties with self-regulation (Cook et al., 2005; Kelley et al., 1997; Ireland et al., 2015). As youth in the legal system (YLS) are more susceptible to higher rates of traumatic events and low self-regulation, this is a key population to consider when evaluating the relationship between trauma and the development of self-regulation. Additionally, research has shown that youth that experience parenting consistent with secure attachment are more likely to develop strong self-regulation (Bernier et al., 2010; Lengua et al., 2007). Thus, within the population of YLS it is also important to consider how tendencies toward insecure attachment styles (i.e., anxious and avoidant) influence self-regulation. This study examined whether the number of traumatic events influenced self-regulation, as measured by difficulties in emotion regulation and deficits in executive function. The study also examined the relationships between insecure attachment styles and self-regulation. Data utilized in the current study were from an ongoing 5-year longitudinal project targeting YLS. Correlation and simple linear regression analyses were used to address relationships among the five factors. Results indicated a significant positive association between traumatic events and both forms of self-regulation (i.e., difficulties in emotion regulation and deficits in executive function). A significant positive relationship was also found between both insecure attachment styles (i.e., anxious and avoidant) and difficulties in emotion regulation. No relationship was found between insecure attachment styles and deficits in executive function. Results of this study provide preliminary evidence of the relationships between attachment styles and trauma on self-regulation, indicating trauma and attachment as potential underlying mechanisms of self-regulation. These results are informative for interventions targeting positive change in self-regulation within the population of YLS.

The development of better signal-to-noise processing of important sensory stimuli is adaptive. Research with humans has found that visual cues presented before (pre) or after (retro) the occurrence of relevant environmental events direct attentional resources toward those events, improving reaction time and accuracy of detection. Nonetheless, it is not clear if these cues direct attention to specific features of the relevant stimuli, the surrounding environment, or some other characteristics of the situation. Identifying visual search patterns using techniques like eye tracking may clarify the mechanisms that support improved performance, particularly when pre and retro-cues are involved. Students between the ages of 18-35 were recruited using TCU SONA System. Participants were asked to compare a probe stimulus to a sample stimulus based on its identity or location, using visual pre and retro-cues (coloured backgrounds). We hypothesized that participants will exhibit higher accuracy and lower reaction time on cued trials compared to control trials (neutral cues), as well as longer fixations to the center of the object on spatial trials, and longer saccadic amplitude on identity ones. These results have implications for the design of instrument panels and implementation of training techniques (e.g., equipment and sports).

Environmental socio-scientific topics are commonly taught in university courses. Interestingly, researchers, who have utilized climate change as a socio-scientific issue, have identified that following engagement in planned activities, students experienced an increase in content knowledge but could not view themselves as environmental agents of change (Ballantyne et al., 2016; Shepardson et al., 2011; Stevenson et al., 2014). Science literacy for environmental issues is vital. However, if students lack the ability to see themselves as being able to assist or have agency in the mitigation of environmental issues, these problems will persist. Community (citizen) science is an instructional method that falls under the experiential learning umbrella and has been explained as “the engagement of non-professionals in scientific investigations – asking questions, collecting data, or interpreting results” (Miller-Rushing et al., 2012, p. 285). McKinley et al. (2017) advocated that engagement with community science prepares and empowers participants for involvement in policy discussions and decisions and to educate and motivate their communities to participate in conservation. Applying this notion to community science projects centered on environmental issues suggests that students may be more likely to be motivated to engage in environmental action following engagement with community science activities. While there are a few research studies that have utilized community science to study undergraduates' motivations, gains in content knowledge, and interests in science; even fewer studies have been conducted in undergraduate courses to study undergraduates’ self-efficacy for science and environmental action. The participants in this study are science major and non-science major undergraduate students (18 years or older) enrolled in a Ranch Management core curriculum course at a university in the Southern region of the U.S. The primary objectives of this study are to identify the degree to which non-science majoring and science majoring undergraduate students’ self-efficacy for learning and doing science changes after engaging in a community science intervention. Preliminary findings indicate that both groups increased efficacy while differences were found. The findings from this research will contribute to informing educators in science departments about non-science and science majoring undergraduate student experiences with socio-scientific-based community science projects.

Citizen (community) science platforms have become a crucial aspect of involving the public in scientific research. The platform Zooniverse particularly has grown to include a wide range of participants in the scientific community. Though there is a substantial amount of literature surrounding the efficacy of community science platforms, relatively few studies tackle applications in undergraduate education. This study investigates undergraduate student engagement with Zooniverse. Utilizing Zooniverse, participants analyzed the flowering of North Texas prairie species. Primary objectives include documenting the accuracy and speed of student identifications and comparing potential differences between historical botanical specimen images provided by the Botanical Research Institute of Texas and images collected from iNaturalist. These findings will help inform the usage of community science platforms in undergraduate education spaces and more particularly for non-science majors.

As the number of antibiotics in development dwindles and antibiotic resistance continues to rise,
there is a need for novel, non-traditional antibiotics such as zinc oxide nanoparticles (ZnO NPs).
While the broad-spectrum antimicrobial properties are well established, the mechanism of action
is still unknown. Previous work has proposed that reactive oxygen species (ROS), toxic Zn2+ ions,
and electrostatic interactions with the cell envelope may be implicated in the mechanism. To
evaluate which of these mechanisms are involved, we characterized the physical and genetic
properties that confer resistance to ZnO NPs in three novel ZnO resistant strains of
Staphylococcus aureus (ZnOR). These strains possess comparable growth rates and are at least
four times more resistant than the parental strain against ZnO NPs acquired from multiple
sources. This suggests that all ZnO NPs, regardless of morphology, size, or method of synthesis
share a mechanism of action. We found that cell charge, measured by cytochrome c, was not
different between the parental and resistant strains, indicating that electrostatic interactions
with the membrane are not involved in the mechanism. Additionally, the ZnOR strains shared a
similar susceptibility to H2O2, a ROS commonly suggested to be generated by ZnO. We have also
found that internalization and physical contact with the bacterial envelope are not necessary for
ZnO mediated growth inhibition suggesting that ZnO produces a soluble species that is
responsible for the antibacterial action. Future work includes sequencing the genome of the
parental and ZnOR strains to identify mutations that led to gain of resistance.

Bacillus anthracis is the causative agent of the fatal disease anthrax, and its virulence is of great interest due to its potential as a biological weapon. B. anthracis causes disease by both escaping immune defenses and acquiring nutrients. A necessary nutrient that pathogens must acquire from its host is iron. To discover novel genes essential for iron acquisition, we screened transposon mutants in iron-deficient media with hemoglobin as the sole source of iron. We further prioritized the mutants discovered in our in vitro screen by assessing for attenuated virulence using our in vivo G. mellonella infection model. We found one mutant that has a disruption in the first gene of a two-gene operon containing putative dUTPase and aminopeptidase genes known as 9F12 Tn. Neither of these genes have been previously linked to iron acquisition. To confirm the role of the dUTPase gene in the observed 9F12 Tn phenotype, we created an independent insertional mutant in the dUTPase gene (dUTPase IM). We found that both of our mutants, 9F12 Tn and dUTPase IM, could not use hemoglobin as a source of iron. We also found that G. mellonella injected with 9F12 Tn and dUTPase IM had higher survival rates than those injected with the parent strain. Our results indicate that the dUTPase gene is necessary for iron-acquisition and virulence in B. anthracis. This study furthers our understanding of iron acquisition in a bacterial pathogen and increases our knowledge of how B. anthracis causes disease.

Bacillus anthracis is a gram-positive bacterium that causes the deadly anthrax disease. ClpX is a subunit of ClpXP protease that is known to be essential in virulence as well as providing resistance to cell-envelope targeting antibiotics such as penicillin, daptomycin, and the antimicrobial peptide LL-37. While clpX is critical for virulence in B. anthracis, it is unlikely to be directly mediating the effect. Hence, our lab investigated the genes that are differentially expressed in the ΔclpX mutant compared to the wild type B. anthracis through microarray analysis. We found 119 genes that were highly differentially expressed in the ΔclpX mutant. In this study, we focused on two genes sigM and glpF, which are downregulated in the ΔclpX mutant, because sigM and glpF confer resistance to cell-wall targeting antibiotics in the closely related gram-positive bacterial species, Bacillus subtilis and Staphylococcus aureus respectively. We wanted to determine whether loss of sigM and glpF will lead to similar phenotypes as loss of clpX in B. anthracis Sterne. We found that sigM mutant is more susceptible to penicillin and daptomycin, although in a growth phase dependent manner, but glpF mutant is not. Future studies will examine the susceptibility of these mutants to LL-37 and other stressors such as acid and heat stress. Complementation of these mutants will serve to further support the importance of these genes for the roles we examined. This research will aid in understanding the mechanism of antibiotic resistance and virulence in the ClpX regulatory network in B. anthracis.

Salmon hatcheries are widely used across the Pacific Northwest to enhance fisheries and supplement declining wild populations. However, substantial evidence suggests that hatchery fish have reduced fitness compared to their wild counterparts. Domestication selection, or adaptation to the hatchery environment, poses a potential risk to wild populations if introgression between hatchery and wild fish occurs. While few studies have investigated domestication selection on a genomic level, none have done so in parallel across multiple hatchery-wild population pairs. In this study, we examined three separate hatchery populations of Chinook salmon, Oncorhynchus tshawytscha, and their corresponding wild progenitor populations using low-coverage whole genome sequencing. We sequenced 192 individuals from populations across Southeast Alaska and estimated genotype likelihoods at over six million loci. Each hatchery population, which was reared in a hatchery for approximately seven generations, was then compared to its wild progenitor population using multiple metrics of genomic divergence. While evaluating population-level genomic differentiation (FST), we discovered numerous outlier peaks in each hatchery-wild pair, although no outliers were shared across the three comparisons. Further analyses indicated that these relatively small (5 – 10 kilobase) peaks are likely due to genetic hitchhiking on hatchery-selected alleles, though the effects of these peaks on fitness are unknown. Overall, our genome-wide analyses demonstrate that domestication selection is prevalent in all hatchery facilities, but the genetic pathways differ across populations, possibly due to a polygenic basis of fitness related traits. These results provide fine-scale genetic evidence for domestication and highlight the need to assess if certain management practices, such as integration of wild broodstock, can universally mitigate genetic risks despite multiple pathways of domestication.

Oxidative stress caused by the imbalance between antioxidants and oxidative species is a major component of several chronic diseases such as cardiovascular disease, cancer, and some neurodegenerative diseases. Potential therapeutics have previously been explored to address the role of oxidative stress in disease, but many have been unsuccessful or only target one aspect of this multifaceted disease pathway. To address this, Dr. Green’s lab at TCU created the L2 compound to act as a multimodal antioxidant therapy. Specifically, preliminary in vivo studies have demonstrated L2 can increase the cellular level of nuclear factor-erythroid 2-related factor (Nrf2), the natural antioxidant pathway of the cell. Normally this pathway is activated due to oxidative stress, allowing Nrf2 to migrate to the nucleus where it acts as an important transcription factor to produce antioxidant and detoxifying enzymes. This data was unexpected as the addition of antioxidant compound L2 should mitigate the need to activate the Nrf2 antioxidant pathway. Therefore, it is the purpose of this study to confirm that treatment of cells with L2 results in translocation of Nrf2 into the nucleus of cells. Further experiments will determine if this translocation leads to antioxidant effects as proposed.

Wind-energy production has expanded due to interest in increasing energy production and decreasing reliance on fossil fuels. Unfortunately, collisions and fatalities are unintended consequences of wind-energy production for many bat species. The Mexican free-tailed bat (Tadarida brasiliensis) has a non-migratory population in California that has an assumed sex ratio of 50:50, as seen in other nonmigratory bat species, and migratory sex-skewed (9:1 Female:Male) population in Texas that arrives in the summer to form maternal colonies. Knowing how males and females are impacted by collision mortality at wind turbines can provide insights into population-level effects. We determined the sex of bat carcasses discovered at wind turbines using DNA extracted from wing tissue samples collected during post-construction surveys in California (n = 502, 5 years) and Texas (n = 437, 3 years). Preliminary analysis of bats from California suggests that the sex ratio of fatalities did not differ significantly from 50:50 from 2016 to 2020 (p>0.05). In contrast in bats from Texas, the sex ratio of fatalities was significantly female-skewed in 2017 (6.8:3.2, z=3.25, p<0.001), became less female-skewed in 2018 (4.8:5.2) and 2021 (4.4:5.6), with neither 2018 nor 2021 being significantly different from 50:50 (p>0.05). This change in sex ratio in Texas might be demographically relevant if the loss of females from previous years is causing the migratory population to become less female-skewed over time. Studies of sex ratios at summer and winter colonies would allow determination of whether this same pattern is observed at the population level.

Oxidative stress is the imbalance between reactive oxygen species and antioxidants in a cell. Often this imbalance is caused by an increase of reactive oxygen species (ROS) leading to dyshomeostasis of the cellular redox balance. Oxidative stress is a major component of several chronic diseases including cardiovascular diseases, cancer and neurodegenerative diseases like Parkinson’s and Alzheimer’s diseases. To mitigate the damage caused by oxidative stress our cells are capable of producing their own antioxidants. One cellular mechanism involves the nuclear factor-erythroid 2-related factor (Nrf2) antioxidant pathway which can be activated in the presence of ROS. To better understand how this pathway works, it is important to track Nrf2 during activation of this pathway. Here we test three different plasmids designed to either force expression of “tagged” proteins in the Nrf2 pathway, or to provide a readout mechanism for the level of Nrf2 activation. These experiments lend support for the efficacy of using these tools to better understand the Nrf2 pathway.

The Thule Defense Zone in Northwest Greenland is a region of ecological concern because of its sensitive Arctic tundra ecosystem. Anthropogenic-induced climate change and deposition of contaminants into these fragile systems has the potential to alter these ecosystems. Mercury is a toxin of global importance that is capable of contaminating landscapes far from its source of origin, including those in the high Arctic. Understanding levels of mercury contamination that persist across landscapes requires analysis of aquatic ecosystems, as these systems are where mercury is converted into its toxic form, methylmercury. In Summer 2023, the Aquatic Ecology Lab at Texas Christian University will be traveling to the Thule Defense Zone and testing six ponds for mercury contamination. To better understand how contaminants reach these ponds, nutrient inputs from the landscape need to be understood. To date, there is no available watershed map for the Thule Defense Zone that delineates the hydrological characteristics of these ponds. My project will use Geographic Information Systems (GIS) to create a formal delineation of these aquatic systems.

Biodiversity, which is important to the function and stability of ecosystems, is currently being lost to extinction at an alarming rate. Thus, cataloguing and documenting the biodiversity of the world has never been more critical. In this study, the diversity and taxonomy of the tropical blueberries (Vaccinium L., Ericaceae) of Palawan and Mindanao Islands, Philippines were revisited. A total of 27 species (24 from Mindanao and four from Palawan) were documented and recorded. Six novel species, four new island records, and clarification of three ambiguous species complexes were included. Two of the six novel species (V. jubatum and V. vomicum) were discovered among historical herbarium collections, while the rest (V. carmesinum, V. coarctatum, V. fallax, and V. gamay) were discovered during botanical excursions. Two previously island endemic blueberries, V. cebuense and V. banksii, were documented to have an extended distribution in Mindanao. Additionally, V. irigaense is also recorded in Mindanao, whereas V. pseudocaudatum is recorded for the flora of Palawan. Further, the V. barandanum, V. caudatum, and V. halconense species complexes were taxonomically explained. The nomenclatural status of these species was stabilized through assigning type specimens following specifications of the International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code). We concluded that Mindanao Island is the center of Philippine Vaccinium diversity. This study underscores the crucial role of herbaria in understanding the floristic diversity of the world. This study also serves as a basis for taxonomical studies of the other blueberries in the Philippine Islands and Southeast Asia.

The Great Salt Lake in Utah is an important stopover point for many migratory bird species. Birds that stop to breed or forage at the Great Salt Lake may be at risk of mercury contamination due to high levels of methylmercury that are found in the lake. The purpose of this study was to examine the transfer of mercury from the lake into the terrestrial food web using organisms at the base of the food web. During the summers of 2019-2021 western spotted orb weaver spiders (Neoscona oaxacensis) and, when possible, brine flies (Ephydra sp.) were collected from various sites on Antelope Island. These specimens were analyzed for total mercury content using a Nippon MA-3000. In addition, satellite imagery and GIS software were used to document the approximate distance from the collection sites to the water surface. We examine differences between years, study sites and spider body size. We also examined the correlation between mercury levels and environmental conditions.

Barriers to rotation within triazine compounds have been previously explored by Katritzky and Birkett [1-2], but these studies have been limited to differences in the substituent groups on the triazine as well as the degree of substitution (mono, di, tri). This study explores how the barriers to rotation within triazine containing compounds are affected by solvent and protonation state. Overall, these molecules are of interest due to their wide range of applications in dendrimer and macrocycle synthesis as well as pharmaceutical drug development [3-4]. The results of this study illustrate how solvent selection can significantly impact the distribution of rotational isomers (rotamers) and how barriers to rotation can be increased by protonation of the triazine ring.

Metal-halide perovskites are crystalline materials that work as a semiconductor in both Light Emitting Diodes (LEDs) and solar cells. In general, perovskites possess the formula ABX3. For this project, the A site is an organic molecule such as Methylammonium (MA), the B site is Lead, and the X site is Bromide. While perovskites are easily fabricated, their crystal size and number of defects present are challenging to control. Defects cause LEDs to be less stable and/or less photoluminescent (bright) and cause solar cells to be less efficient at converting light to energy. One approach to reduce the number of defects is to use ionic liquids during perovskite formation. Ionic liquids are compounds made of ions in the liquid state due to a low melting temperature. They can be added to the perovskite precursor solution to slow down the crystallization process so that fewer defects are created. The goal of this project is to create new metal halide perovskites in the presence of selected ionic liquids, evaluate their structure and photophysical properties, with the long-term goal of creating new LEDs that are both stable and efficient.

In this project, cetyl-ionic liquids (cetyl meaning 16 carbon chains) were investigated for their effects on perovskite structure and light emission. The three ionic liquids were investigated: [C16-mim]Br (referred to as "IL1"), [C16-py]Br ("IL2"), and [C16-C1pyrr]Br ("IL3"). Variations on the addition method of ionic liquids to the perovskite precursor were studied as well. It was hypothesized that the inclusion of cetyl-ionic liquids will protect the perovskite films from the environment (increasing stability) by providing a hydrophobic layer on the surface and will improve the electronic properties by filling in pinholes that cause defects. It is found that perovskite films with IL3 are more photoluminescent than the perovskite films formed with IL1, IL2, or no IL (control). Preliminary experiments varying the addition method of IL3 during film formation have shown that the perovskite films are brightest when IL3 is added to both the precursor and the antisolvent layers at the beginning of the fabrication process. These results, along with detailed structural characterization of a given perovskite film, will be discussed in this presentation.