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.

Characterizing Galactic sub-structures is crucial to understanding the assembly history and evolution of the Milky Way. To accomplish this, we need to identify and analyze the accreted sub-structures. With ESA Gaia and SDSS-IV/APOGEE, studies have been done to analyze the kinematics and chemical abundances, respectively. However, one challenge that still remains is deriving reliable ages for these sub-structures. We utilize the new relationship between the carbon to nitrogen ratio and stellar age derived by the OCCAM team, which has recently been extended to the metal-poor regime, to probe stars within the sub-structures in the metallicity range -1.2 ≤ [Fe/H] ≤ +0.3 dex. This allows us to determine the ages of a greater number of stars within these sub-structures, which paints a more coherent picture of the original galaxies that have been disrupted to form the Milky Way’s halo. Using the sample of halo sub-structures in Horta et al. (2023), we apply the newly extended calibration to determine ages of stars within these sub-structures and compare them to previous age estimates.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Aim. This study aims to explore the feasibility, acceptability, appropriateness, and reliability of a new observational assessment tool - the Child and Adolescent Wellbeing Scale (CAWS), designed to evaluate socio-emotional health and attachment patterns in children and adolescents.
Background. There is significant interest in child trauma and interventions, and therefore a need for an assessment tool to assess child-level outcomes of trauma-informed interventions, care, and services. The CAWS was created to address this gap, providing a measure rooted in child-caregiver attachment and relational trauma. The CAWS is a 25-item scale with three subscales: Connection, Regulation, and Felt-Safety, which align with Bath’s Three Pillars of Trauma-Informed Care.
Method. Twenty mental health clinicians were trained to use the CAWS during two virtual sessions. Following training, each participant independently observed and rated 15 pre-recorded video interactions between children and their caregivers (totaling 300 independent ratings). Clinicians provided feedback on the CAWS instrument content and format after rating the videotaped interactions; validated measures were used to evaluate the feasibility, acceptability, and appropriateness of the instrument. Reliability estimates were calculated using the generalizability theory.
Results. Ninety-four percent of participants (95% white, 85% female, median age 40.5 years, 100% Master’s degree) reported that administering the CAWS was feasible (i.e., implementable, doable), 100% indicated it was acceptable (i.e., appealing, meets approval), and 100% indicated it was appropriate (i.e., suitable, applicable). Additionally, 100% of participants reported that they would likely use the CAWS in their practice. The CAWS demonstrated excellent inter-rater reliability overall (R1F = .82), was a reliable measurement of systematic change in children (Rc = .94), and reliability emphasized the stable individual difference between children (RKF = .98).
Conclusion. The current study demonstrates the CAWS as a promising evaluation tool with excellent reliability, feasibility, acceptability, and appropriateness. Additional studies should investigate the CAWS instrument's validity further, focusing on its applicability in field settings and its utility in measuring change over time.

The phenomenon of helicopter parenting, or a parent’s overinvolvement in their children’s lives, has been previously studied in populations of college students. Helicopter parenting is associated with negative effects on child well-being and parental closeness in this population. Current research is sparse, however, with very little research examining helicopter parenting in non-college student populations. The current study aims to (1) replicate previous findings on the effects of helicopter parenting in a non-student population; (2) explore the relationship between helicopter parenting and wellbeing substance use, and justice involvement; and (3) examine associations between demographic variables and helicopter parenting. This poster focuses on the methodology being implemented in the current study, as well as an examination of current literature surrounding helicopter parenting.

Terror management theory suggests that the potential for anxiety from the awareness of death can be buffered by a cultural worldview. Mind-body dualism, the belief that the mind and the body are separate, might affect people’s mortality concerns. Given that the body is threatening given its vulnerability to death, individuals who perceive the mind and body as being connected (vs. separate) should experience higher mortality-related thoughts and defense of their cultural beliefs. Past research found that mind-body dualism was related to afterlife belief, which was able to buffer existential concerns (Heflick et al., 2015). Based on these findings, the current research investigated how mind-body dualism moderated the effect of the creaturely body on death-related concerns. The result showed that people who perceived the mind-body relationship as more separate showed significantly fewer death concerns after reading an essay emphasizing the creatureliness of the body, whereas people who held beliefs in a more interrelated mind-body relationship showed heightened death concerns after the creaturely body prime.

Reintroductions have become increasingly common to help restore populations of Texas horned lizards (Phrynosoma cornutum). Reintroduction success of any species can be shaped by many factors including genetics, selection of suitable reintroduction sites, etc. Our primary goal has been to determine whether release techniques- specifically site selection and release method- contribute to the reintroduction success of captive-bred hatchling Texas horned lizards. In 2020 and 2021, we reintroduced over 500 captive-bred hatchling Texas horned lizards from the Ft. Worth, Dallas, and Caldwell Zoos to Mason Mountain WMA (Mason County, TX). Lizards were randomly assigned to one of two release sites and were placed either in clumps of 20+ lizards (Site 2 2020 & Site 1 2021) or were dispersed 5 m from one another (Site 1 2020 & Site 2 2021) at release. We used harmonic radar to track lizards and monitor survivorship outcomes and growth rates from release (September or October) until most lizards began brumating in early December. We found that survival outcomes were associated with both release site (χ22, 509 = 34.5, p<0.0001) and release method (χ22, 509 =15.09, p=0.005). We achieved the highest survivorship (26.4%) when lizards were dispersed at Site 1. Preliminary dietary and prey availability assessments suggest that survivorship differences between locations may be related to differences in food availability. Our findings suggest that future reintroduction attempts may have higher success rates if 1) sites are selected that meet the specific resource requirements of hatchlings, and 2) lizards are dispersed from one another at release.

Anthrax is an infectious disease caused by Bacillus anthracis, which is a spore forming bacterium. Even though the anthrax toxins and capsule, encoded on 2 plasmids pXO1 and pXO2, play crucial role in the pathogenesis of anthrax infection, evidence suggests that chromosomal genes also play a role. The ClpX ATPase was discovered to be crucial for B. anthracis virulence via protection against host antimicrobial peptides. In this study, we want to investigate the role of clpX in regulation of other stressors including acidic stress, temperature stress, salt stress, and non-cell envelope active antibiotics. We found that clpX is necessary for survival in an acidic environment and growth under heat stress. We demonstrate that acidic stress resistance is mediated by the formation of the ClpXP protease using a ClpX complementation plasmid that is incapable of interacting with ClpP. There is no association between clpX with other stressors. We conclude that the ClpX is required for B. anthracis pathogenicity via defenses against host antimicrobial peptides and for survival in an acidic environment. Understanding the role ClpX in the regulation of stress responses will ultimately infer us with new target for either directly combating infection or improving the efficacy of already available medicines.

Impacts of Pollen-Donor Distance and Nutrient Availability on
Reproductive Success in a Carnivorous Plant

Halia Eastburn and John Horner

The maintenance of genetic diversity has important consequences for the survival of plant populations. Because plants are sessile, the distance between plants is often inversely correlated with relatedness. Therefore, the distance between pollen-donor and recipient can determine the level of inbreeding or outbreeding. Both pollen-donor distance and nutrient availability can affect reproductive success in populations of flowering plants. Populations of the carnivorous plant Sarracenia alata have dwindled and become extremely fragmented due to human development and agriculture. The purpose of this study was to examine the effects of pollen-donor distance and prey capture on reproductive success in S. alata. We hand-pollinated flowers with pollen from varying distances [0 m (self-pollinated) and 35, 60, 90, 125, and 190 m], and we prevented prey capture in half of our study plants. We measured seed production and germination to estimate reproductive success. Pollen-donors from greater distances sired a greater number of seeds but pollen-donor distance did not affect germinability. There was no effect of prey capture alone nor an interaction of pollen-donor and prey capture on seed production or germination. More research is needed to understand nutrient allocation for reproduction over multiple years and natural variance in prey capture which might affect reproductive output in subsequent seasons.

Due to habitat loss the Texas horned lizard (THL) (Phrynosoma cornutum) population has declined across its historic range. To date, reintroduction attempts for the species have been unsuccessful, calling into question the suitability of the habitat. Texas horned lizards require suitable thermal habitat to meet their thermoregulatory needs, because of this, understanding the thermal habitat requirements of THLs is important. While the critical temperature limits and preferred body temperatures of THLs are established from laboratory studies, thermal habitat preferences for THLs in the wild are poorly understood. The objective of this study was to determine thermal habitat preferences and home range sizes of reintroduced THLs at Mason Mountain WMA compared to a nearby natural population of THLs on the White Ranch. We also compare the thermal conditions of different microhabitats between the two sites. To compare thermal conditions between the two sites, we used thermal dataloggers to record the temperatures in different microhabitats throughout the day at each study site, then compared how much of the time these data loggers were within the lizard’s optimal temperature range between the two study sites. Home ranges were calculated for lizards from the two study sites and average home range sizes between the two study sites were compared for significant differences. The ground temperature selected by the lizards versus random points were compared between the two study sites. These findings will improve our understanding of THL thermal ecology and reintroduction requirements.

Metal Halide Perovskites (MHPs) are an emerging type of semiconductor for use in electronic devices that produce or utilize light. MHPs have shown advantages over traditional semiconductors such as silicon due to ease of solution processing, high defect tolerance (defects are strained chemical bonds and/or missing atoms in the crystal lattice) and tunable emission of light color. MHPs have the chemical structure ABX3 where A is a monovalent cation (+1) such as cesium, methylammonium or formamidinium; B is a divalent cation (+2) such as lead or tin, and X is a halide such as chloride, bromide, or iodide. Their favorable properties have resulted in solar cells capable of 32.5% power conversion efficiency in a tandem perovskite/silicon solar cell. However, MHPs suffer from issues with long term stability brought about by exposure to air and moisture, as well as ion migration under illumination.
Crystal engineering and chemical passivation using small molecules have been implemented to improve the long-term stability and reduce ion migration. Incorporation of small molecules with charged groups onto a MHP helps to mitigate surface defects by occupying surface sites of missing atoms or strained bonds. Recent work has shown incorporation of these small molecules during MHP synthesis results in the formation of two dimensional layers on top of the three-dimensional perovskite crystal resulting in increased long-term stability, resistance to heat and moisture, and reduction in ion migration at grain boundaries. Current work in our lab involves synthesizing thin films of methylammonium lead tribromide by spin coating and incorporating a macrocycle based on triazine molecules for this purpose. This presentation focuses on the effects of triazine treatment on the above perovskite, as evaluated by photoluminescence microscopy, powder x-ray diffraction, and scanning electron microscopy.

Salt-induced diffusiophoresis is the migration of a colloidal particle in water caused by a salt concentration gradient. Recent studies have shown that diffusiophoresis can be used for controlling particle motion, with potential applications in separation science, microfluidics, and enhanced oil recovery. These applications are especially appealing for nanoparticles with host-guest properties such as micelles. In this work, Rayleigh interferometry was used to experimentally characterize diffusiophoresis of tyloxapol micelles in the presence of the strong salting-out agent, sodium sulfate, in water at 25oC. Our results show that micelle diffusiophoresis occurs from high to low salt concentration. A model based on micelle preferential hydration was used to quantitatively explain our findings. At relatively high salt concentrations, liquid-liquid phase separation (LLPS) was observed. Near this phase transition, micelle Brownian mobility was found to dramatically decrease, making micelle diffusiophoresis the dominant transport mechanism. Our work suggests that salting-out agents and proximity to LLPS can be used to control the motion of micelles and hydrophilic nanoparticles in general.

Catalases are a class of metalloenzymes responsible for the protection of cells from damage caused by hydrogen peroxide by converting it into water and oxygen. Manganese-based catalase (MnCAT) has been identified in different organisms as an antioxidant, raising the interest in developing small molecules as biomimetic models. A Mn(III) complex of pyclen, a 12-membered ring pyrinophane macrocycle, has previously shown to be a functional mimic of MnCAT in our laboratory. In the present study, modifications of the pyridinophane macrocycle were used to evaluate their impact on the catalytic disproportionation of hydrogen peroxide. Two series of ligands were studied: (1) varying the number of pyridine moieties within the macrocycle, and (2) substitutions in the 4-position of the pyridine ring. pH-potentiometric titrations were used to determine the formation constants (log ß) of each manganese complex, which allowed us to derive speciation curves in solution. The initial rates method was used to calculate the kinetic-relevant parameters for the disproportionation reaction. The results emphasize the effect of structural differences of the ligand on modulating the reactivity of manganese, which are the basis of a mechanistic study of the reaction that is currently underway.

N-alkylation of amino acid-containing pharmaceuticals has been shown to increase their respective oral availability and membrane diffusion. Macrocycles, too, have been an interest in modern drug design due to their ability to have a dynamic conformation and adopt a chameleon-like property to enhance the ability for the drug to be properly delivered in a multitude of environments, and similarly macrocycle's ability to fully envelope an active site to block enzymatic activity. In this project, four novel N-alkylated amino acid-linked triazine macrocycles were synthesized from cyanuric chloride using BOC-hydrazine, an N-alkylated amino acid, and dimethylamine. Coupling of the amino acids with EDC to form the acetal product and further acidification and removal of protecting groups with trifluoroacetic acid yielded macrocycles in good yield. Characterization via 1D and 2D NMR reveals the emergence of different conformations in varying proportions. These conformations result from by the restricted rotation around the Ar-N bonds of both the hydrazine and amino acid of the macrocycles. A previous, non N-alkylated, glycine macrocycle was used as a reference compound, and the emergence of the different conformations was not observed for this molecule. Furthermore, the N-methylated glycine macrocycle displayed an asymmetric configuration, whereas the proline macrocycle was too rigid around the Ar-N of the amino acid to form the different rotamers. The successful synthesis of these N-alkylated amino acid macrocycles shows that further customization of these triazine macrocycles is possible.

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.

This project aims to incorporate unnatural amino acids into proteins using an ortogonal pair composed by a leucyl synthetase from Methanobacterium thermoutotropicum (MLRS) and tRNA from Halobacterium sp. NRC-1 (HL-TAG3). A plasmid called pRCG was designed to contain a cat-upp fusion gene with amber stop codons at permissible sites of the chloramphenicol acetyl transferase protein (CAT). Three variations of the pRCG plasmid were tested: Q98TAG, D111TAG, and a double mutant containing both mutations. To study the amber codon suppression ability of the mutants, a functional leucyl-tRNA synthetase lacking the editing domain was tested for the incorporation of its endogenous amino acid using the three pRCG variants. To show that the amber stop codon is being suppressed, E. coli GH371 cells must survive when grown in the presence of leucine and chloramphenicol because the full-length CAT is expressed. In contrast, when grown in the presence of 5-fluorouracil (5-FU) and leucine, cells will not survive because the MLRS produces a full-length uracil phosphoribosyl transferase protein (UPRT) that converts 5-FU to a toxic product, causing the cells to die. Only Q98TAG or D111TAG mutant was able to suppress the amber stop codon when E. coli GH371 cells were grown in the presence of leucine under positive and negative selection conditions. The Q98TAG variant showed higher suppression ability. A library of MLRS with five randomized amino acids in the active site was designed and selected using the pRCG Q98TAG system and two unnatural amino acids (UAAs): 4-nitro-1-phenylalanine and 2-amino-3-(5-(dimethylamino)naphthalene-1-sulfonamide)propanoic acid (Dansyl-Dap). The obtained variants are currently under study to test their ability to incorporate these UAAs into a model protein called Z-domain

Catalase is one of the most efficient antioxidants metalloenzymes in biology responsible for the decomposition of hydrogen peroxide into water and oxygen. The desired antioxidant activity of catalase for medical and industrial application has inspired the study of metal-based mimics of catalase activity. However, very few of these studies explored iron-based mimics, their mechanism of action and the impact of the metal center environment on the activity of the complex. In this study, the first goal is to investigate pyridine containing macrocyclic Fe (III) complex (L1) as catalase mimic. Mass spectroscopy and UV-Visible spectrophotometry were used to follow the mechanistic activity of FeL1. The second goal is to evaluate the impact of adjusting the electronic properties (L2 and L3) and the structural rigidity (L1 and L4) of the ligand on the activity of the complex. Cyclic voltammetry, X-ray structural analysis, potentiometric titration, and UV-Visible spectrophotometry were conducted to characterize and study the properties of all the complexes. Kinetic studies following the initial rate method and TON studies were conducted to compare their activity.