Both Breast Cancer Gene 1 (BRCA1) and Partner and Localizer of BRCA 2 (PALB2) interact through their coiled-coil domains and are critical for proper functioning of DNA repair through homologous recombination. Individuals who carry pathogenic variants in either protein have an increased risk of developing breast cancer. Multiple variations of unknown significance (VUS) have been documented within the coiled-coil region of each protein, meaning a person carries a variation in either BRCA1 or PALB2 but there is not enough data to know the clinical significance of those variants. In this study, we analyzed the structural effects of five proline VUS within the binding region of BRCA1 and PALB2, three variants that have been discovered in patients and two variants that have not yet been discovered in patients. We used a known benign valine variant and a known pathogenic proline variant as our negative and positive controls, respectively. Because proline variants are known to disrupt protein structure, we hypothesize the proline variants will inhibit coiled-coil formation and, in turn, disrupt interaction between BRCA1 and PALB2. Each coiled-coil construct was generated in vitro and its structure analyzed using circular dichroism first individually and then in the presence of its wild-type binding partner. While all proline variants affected the structure of BRCA1, they had different degrees of impact depending on where they are located in the coiled-coil. This suggests that proline variants impact the ability of BRCA1 to form a coiled-coil in the presence of PALB2 and may be pathogenic. Notably, however, the BRCA1 proline variants seem to cause different structural changes from the pathogenic PALB2 proline variant. This prompts further research to determine the structural effects on the residue level and to correlate structural changes with functional changes.

Alzheimer’s disease (AD) is a neurodegenerative disease that is the most common cause of dementia. There is currently no cure for AD, which means the best alternative is developing preventative strategies, such as adoption of the Mediterranean diet (MD), which has been shown to reduce risk of AD development and mortality. In comparison, a typical American diet has been shown to increase risk of AD development. Although the ability of dietary factors to alter the propensity of development of AD is well established, the mechanisms through this is mediated is unknown. One largely unexplored mechanism of dietary-induced AD prevalence is epigenetic modification to genes associated with AD. The most studied epigenetic modification, DNA methylation of cytosines, has been known to alter gene expression levels. Therefore, this study aims to determine whether dietary influences can induce epigenetic modifications, and subsequently modify expression of genes associated with AD. To do this, DNA was extracted from hippocampal tissue of mice on either a MD or TAD, as well as their offspring who were consuming a control diet. The offspring were included to determine if differential methylation patterns are heritable, thereby implicating transgenerational effects and predisposition to AD development or protection. An epigenetic array was used to identify loci that were differentially methylated between diets, and qPCR was used to determine if differential methylation resulted in significant differences in gene expression. No loci were found to be significantly differentially methylated (p-val<0.0001) with an effect size of 10% or more, nor differentially expressed upon qPCR analysis.

As antibiotic resistance increases and antibiotic development dwindles, new antimicrobial agents are needed. Recent advances in nanoscale engineering have increased interest in metal oxide nanoparticles, particularly zinc oxide nanoparticles, as antimicrobial agents. Zinc oxide nanoparticles are particularly promising due to their broad-spectrum antibacterial activity and low production cost. Despite many studies demonstrating the effectiveness of zinc oxide nanoparticles, the antibacterial mechanism is still unknown. Previous work has implicated the role of reactive oxygen species such as hydrogen peroxide, physical damage of the cell envelope, and/or release of toxic Zn2+ ions as possible mechanisms of action. To evaluate the role of these proposed methods, we assessed the susceptibility of S. aureus mutant strains, ΔkatA and ΔmprF, to zinc oxide nanoparticles. These assays demonstrated that hydrogen peroxide and electrostatic interactions are not crucial for mediating zinc oxide nanoparticle toxicity. Instead, we find that a soluble factor accumulates in Mueller Hinton Broth over time that mediates toxicity and that removal of Zn2+ through chelation reverses this toxicity. Furthermore, we find that the physical separation of zinc oxide nanoparticles and bacterial cells using a semi-permeable membrane still allows for growth inhibition. We conclude that soluble Zn2+ is the primary mechanism by which zinc oxide nanoparticles mediate toxicity in Mueller Hinton Broth. Future work investigating how factors such as particle morphology (e.g., size, polarity, surface defects) and media contribute to Zn2+ dissolution could allow for the synthesis of zinc oxide nanoparticles that possess chemical and morphological properties best suited for antibacterial efficacy.

The spread of red imported fire ants (Solenopsis invicta; RIFA) has frequently been cited as a factor contributing to the decline of the Texas horned lizard (Phrynosoma cornutum; THL). Two hypotheses for this are: 1) direct lizard mortality due to RIFA, and 2) displacement of THL’s main food source, harvester ants (Pogonomyrmex spp.), by RIFA. A new third hypothesis suggests that the invasion of RIFA could be causing a decline in hatchling THL food resources, as their diet is mainly composed of small ant species. Many studies have attempted widespread treatment to eradicate RIFA; however, this could have unintended consequences for non-target ant species that THL depend on. Using a targeted application method, we sought to reduce RIFA populations over the summers of 2022 and 2023 at four sites located at Mason Mountain Wildlife Management in central Texas, a locality with an ongoing THL reintroduction program. At each site, hot dog baits were placed 5 meters apart in 10x10 grids. At treatment sites, one teaspoon of Amdro (a common ant poison) was applied to baits with RIFA thirty minutes after placement. After Amdro was applied, baits were left for 30 minutes and then collected. Treatments were repeated monthly May – August. The effects of each targeted poisoning were evaluated using pitfall traps and ant abundance measurements from baits. Results showed that treatment may have decreased RIFA abundance for both years and had variable effects on hatchling food abundance. Future studies will increase sample size to better detect potential treatment effect.

Approximately 1 in 9 Americans over the age of 65 has Alzheimer’s disease (AD). As the size of this age group is expected to more than double by 2040, the AD prevalence is likewise predicted to increase rapidly. Two key risk factors for late-onset AD include poor diet and obesity. Therefore, long-term nutritional strategies could potentially reduce the development of hallmark AD biomarkers, such as amyloid beta (Aβ), later in adulthood. Researchers have found that diets extremely rich in saturated fats are associated with increased Aβ production in both the cortex and hippocampus of rodents. Conversely, plant-based Mediterranean diets (MD) that are plentiful in unsaturated fatty acids were shown to mitigate Aβ in rodents.

The relationship between diet and AD biomarkers has been explored in prior animal research, yet most studies utilize extremely high fat diets (40-60% kcal fat) or supplement with individual MD nutritional components. To address these limitations, we designed comprehensive, macronutrient-matched Mediterranean and typical American diets (TAD) that mimic human diets in Mediterranean regions and the U.S., respectively. C57BL/6J mice were weaned onto one of the two diets at postnatal day 21. Following 6 months of diet consumption, we found that the TAD increased soluble Aβ1-42 in the brain. Additionally, mice on the TAD had excess hepatic lipid deposition, which is a hallmark of insulin resistance and metabolic dysregulation, a comorbidity linked to AD risk.

Hydrilla verticillata is an invasive aquatic plant found in freshwater systems throughout the United States. Invasions pose a threat to plants and animals that come into contact with the rapidly expanding hydrilla, and recreational activities such as fishing and boating are disrupted when densely packed mats of vegetative material form near the surface of the water. These invasions have historically been controlled using the herbicide fluridone, but resistant hydrilla populations have emerged with mutations in the pds gene associated with the production of phytoene desaturase. These resistant mutant plants are outwardly indistinguishable from the susceptible wildtype, and as such it can be challenging for aquatic systems managers to identify whether or not fluridone can be considered as an effective treatment option without some form of genetic testing. The existing standard process for identifying resistant mutants is a lengthy process that relies on amplifying and sequencing the pds gene. Our work has sought to utilize the process of double-mismatch allele-specific qPCR (DMAS-qPCR) to create a quicker and more cost-effective tool to aid in understanding the extent of fluridone resistant hydrilla. Having designed sets of primers specific to the mutations found within the pds gene, the next step is to apply this method to screening hydrilla samples from a variety of geographies in order to outline the spread of the resistant mutant populations.

The prevalence of antimicrobial-resistant bacteria is a rapidly growing public health crisis. This, combined with a decline in the development of novel antimicrobial therapies, makes the search for unique drug targets essential. Previous work from our lab has identified a promising antimicrobial drug target within Bacillus anthracis, the regulatory ATPase, ClpX. ClpX is essential for virulence in B. anthracis and critical for resistance to a host of cell envelope-targeting antimicrobials. ClpX works with ClpP to form a global protease that regulates a wide range of proteins, including transcriptional regulators. Previously, we conducted a microarray of a ΔclpX mutant and found 119 genes with altered expression. One such gene, msrB, has been studied for reactive oxygen species tolerance in other pathogens. This gene encodes for methionine sulfoxide reductase, an antioxidant enzyme that restores functionality to oxidized methionine residues. Increased msrB expression was seen with oxacillin exposure in S. aureus, indicating a potential connection between MsrB and cell wall-targeting antimicrobials. In B. anthracis Sterne, loss of msrB induces sensitivity to penicillin, but unlike ΔclpX, this phenotype is not seen with daptomycin or LL-37. This suggests that the role of msrB in antimicrobial tolerance may be limited to cell wall active antibiotics. Further experiments will include testing the ΔmsrB mutant with additional cell wall-specific antimicrobials (e.g., bacitracin and vancomycin). Our research provides additional information regarding the role of MsrB in the bacterial cell and its potential suitability as a pharmacological target to increase susceptibility to antibiotics.

Understanding the diversity and distribution of species on Earth is crucial in the face of contemporary threats to biodiversity, such as climate change and unsustainable economic practices. Unfortunately, the process of documenting and describing biodiversity often cannot keep pace with habitat loss and species extinction, especially in tropical regions where the number of undescribed and poorly known species is highest, and where biodiversity is most severely threatened. If this diversity is not documented, it will mean a loss of valuable understanding of the natural world and a failure to recognize species whose societal values remain undiscovered or underappreciated. This research will assess the extinction risk of selected fern species to understand their conservation status. The focus lies on understanding the classification, distribution, and conservation status of a group of species within the fern genus Elaphoglossum, the Elaphoglossum dendricola Clade, consisting of around 12 species distributed in the Tropical Andes, mostly at high altitudes (over 2400 m). This assessment aims to serve as a baseline for future conservation studies of this neotropical group of ferns.

Due to widespread anthropogenic emissions and a global atmospheric cycle, mercury contaminates all aquatic ecosystems, including in the Arctic, at concentrations above pre-industrial baselines. Many seabirds nest in large colonies in the Arctic and are at elevated risk of mercury contamination due to their planktivorous and piscivorous diets and long lifespan. We investigated temporal trends of mercury contamination in five species of seabirds from northwest Greenland. Blood samples were collected regularly since 2010 from adult Atlantic puffins (Fracterula arctica), black guillemots (Cepphus grylle), black-legged kittiwakes (Rissa tridactyla), dovekies (Alle alle) and thick-billed murres (Uria lomvia). Samples were analyzed for total mercury using direct mercury analysis. All species had average blood mercury concentrations between 212 and 769 ng/g-wet weight, concentrations associated with a low risk for mercury toxicity. Individual black guillemots and thick-billed murres had blood mercury concentrations >1,000 ng/g wet weight, concentrations associated with moderate risk for mercury toxicity. Preliminary analyses suggest an overall increase in mercury concentrations in black-legged kittiwakes, dovekies and thick-billed murres over the study period. Comparable temporal studies in the Arctic have shown wide variation in mercury contamination trends. The results of the present study contribute to the understanding of regional mercury trends in the Arctic and efforts to assess the impact of the Minamata Convention.

Silicon-Perovskite tandem solar cells are some of the leading emerging technology solar cells due to their high photoconversion efficiency or the ability to turn light into electricity. These solar cells rely on the ability to harvest a higher percentage of the solar spectrum due to the differences in the two materials. MHPs are an ionic crystal that have the chemical formula 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. Porous silicon is crystalline silicon that has been etched to form pores with properties dependent upon the etching conditions. Porous silicon that has been etched such that the silicon area between the pores is between 1-4nm becomes photoluminescent (PL). It has been shown that the optoelectronic properties of metal halide perovskite (MHPs) grown within porous silicon (pSi) are highly dependent upon the surface area, pore size, and surface chemistry of the pSi. This interaction has led us to investigate the fundamental interactions that occur when nanoscale porous silicon encounters nanoscale MHP, namely the possibility of energy/charge transfer.
We have evaluated two different experimental designs. The first entails adsorbing ligand passivated MHP quantum dots onto a solid piece of luminescent mesoporous Si membrane and allow the solvent to evaporate. The change in luminescence from the pSi can be used to monitor the impact the perovskite has upon the pSi by monitoring the change in intensity and wavelength. The second approach as previously described utilizes MHP quantum dots (QDs) dispersed in toluene which is then titrated with non-luminescent pSi and the PL monitored. The primary impact of the pSi upon the light emission of the perovskite QDs is a significant reduction in the intensity of the emission. Comparisons of different pSi with hydride terminated versus oxide terminated surfaces show a dependence upon the surface chemistry to the change in PL. The PL lifetimes will be measured, and comparisons made to determine the mechanism of energy transfer.

Creating a diverse array of structurally distinct, triazine-containing, macrocycles remain the focus of the Simanek group. Until now, this goal has been accomplished through a straightforward 3 step synthetic route with variation of amino acid incorporation and acetal length. Currently two new approaches to macrocycle synthesis are being pursued. The first approach relies on two like monomers coming together: by changing the relative position of groups in the macrocycle, the persistence of shape can be probed. The second approach relies on two different monomers coming together. Using a similar synthetic route, this strategy, if successful, will allow much finer control over design and engineering these molecules for specific purposes. These libraries of structurally diverse macrocycles are important for the long-term goals of establishing rules that can guide pharmaceutical drug design in these under-explored types of molecules.

Neurodegenerative diseases affect more than 50 million people worldwide. This condition damages and destroys parts of the nervous system, specifically the brain. Our goal is to synthesize a macrocycle ligand mimic of catalase, test the reactivity, and compare it to the current Green ligand library.

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"), [C16-C1pyrr]Br ("IL3"), and CTAB (“IL4”). Variations in the deposition method of the perovskite films 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 IL1 produced through a two-step spin coat deposition method are more photoluminescent than the perovskite films formed with IL2, IL3, IL4 or no IL (control). These results, along with detailed structural characterization of a given perovskite film, will be discussed in this presentation.

Hinges are pervasive in the world today. Most common is a simple mortise door hinge  - defined by the flush stacking of leaves and fully revolute motion. Chemists have long sought to reproduce such structures on the molecular scale. Here, the hinge behavior of large, cyclic molecules is described.  Moreover, hinge motion can be controlled by "gumming up" the parts responsible for motion. While dirt and debris work in the macroscopic world, additional atoms are used in these molecular mimics. Specifically, by increasing the size of groups in the hinge domain, the rate of hinging decreases. Hinge motion is visualized by variable temperature NMR spectroscopy where in, at low temperatures the hinging both faces of the leaves (inside and outside) can be observed. At high temperatures, the hinging speeds up and the inside and outside exchange too quickly to be observed. Unlike hinges of everyday use that require human assembly, the molecular hinges described here assemble themselves. As a result, hinges with identical leaves as well as hinges with mismatched leaves can be prepared. Surprisingly, the results of this assembly process are biased: a statistical distribution of hinges is not observed.  Further studies to understanding this steric (gumming) sorting are ongoing.

Platinum nanocrystals on Silicon nanotubes (PtNCs-pSiNT) exhibit significant anticancer activity via an apoptotic mechanism. To enhance the specificity of this material, we attach folic acid (FA) to the nanotube surface to target folate receptors (FARs) overexpressed in cancer cells. This conjugation is successfully demonstrated through X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT IR). Cell viability assays show an enhanced cytotoxicity toward HeLa cells relative to its non-FA containing analog.

Platinum-based therapeutics, exemplified by the FDA-approved anti-cancer drug cisplatin, are a mainstay in treatment of a range of different cancer types.3 Although this drug can form an adduct with DNA and induce apoptosis, many studies have confirmed that cancer cells can develop resistance to this treatment. Alternatively, small Pt nanocrystals (Pt NCs) have demonstrated arrested growth and apoptosis in cancer cells as a consequence of DNA platination and enhanced strand-breaks initiated by leaching Pt(II) ions from the NC surface in the acidic intracellular environment. Small Pt nanocrystals whose size is less than 3 nm demonstrate a higher reduction in cell viability than those with larger size, presumably owing to a relatively greater exposed surface area for dissolution. This observation, coupled with the identification of downregulation of multiple genes critical for cancer cell proliferation after treatment with Pt NCs, has led to an observed reduction in addressing drug resistance. Such nanocrystals tend to aggregate extensively in an aqueous environment, however, and we have developed well-defined Silicon nanotubes (pSiNTs) as a scaffold for effective nanocarrier for drug delivery of such PtNCs, taking advantage of nanotube high surface area, biocompatibility, and biodegradability. Functionalization with 3-(aminopropyl)triethoxysilane (APTES), followed by incubation with dilute K2PtCl4 solution results in the formation of PtNCs-pSiNTs well dispersed on the pSiNTs to avoid aggregation and release the platinum as the pSiNTs are resorbed over time, which results in significant cancer cell cytotoxicity-ty. To enhance the specificity of this material we conjugate Folic Acid (FA) to the Pt surface using as a Glutathione (GSH) linker, with the goal of enhanced targeting of overexpressed FARs and more selective cancer cell uptake.

Chameleonicity, or the ability for a molecule to change its shape to match its environment, is an often-beneficial quality of potential drug candidates, allowing for greater cell permeation. Our group has previously reported several macrocycles exhibiting dynamic hinging motion, allowing the macrocycles to adopt various conformations and giving rise to chameleonic qualities. However, the extent of hinging (e.g., the rate and barrier to hinging) were contingent on the bulk of an amino acid’s side chain. Here, five 24-membered triazine-based macrocycles are introduced with varying alkyl substituents on the hydrazone moiety of our macrocycles, distant from the hinging axis. The macrocycles are obtained by a facile three step process in high yields at each step, with the macrocyclization yielding quantitative folded and dynamic macrocycles. Using rOesy NMR, the macrocycles’ conformation and rotamer state is shown to be preserved. Variable-temperature NMR reveals that the hinging motion is mostly unaffected by the distant hydrazone substitution, further establishing the location and pathway of the hinging axis. The minimal impact of hinging via these substituents allows for varying groups to be placed away from the axis, preserving the dynamic motion but allowing for tuning of pharmaceutically relevant parameters (e.g., lipophilicity/water solubility with varying alkyl chains) or installment of bioactive moieties. Permeability studies with PAMPA show acceptable passive permeation of the alkyl hydrazone macrocycles, with permeability dependent on lipophilicity and dynamic motion. These results further indicate the ability of these macrocycles to be valid scaffolds for intracellular drug development.

The inclusion of a pyridine moiety in the skeleton of tetra-aza macrocycles introduces rigidity while also introducing a handle by which the electronics and basicity of the ligand can be tuned. Metallation of these pyridinophanes has resulted in active mimics for metalloenzymes, such as superoxide dismutase mimics. However, recent work has explored their potential for industrially relevant catalytic reactions. Previous studies of iron RPyN3 complexes showed moderate success for a direct Suzuki-Miyaura C-C coupling reaction. In that work, it became clear that the substitution on the 4-position of the pyridine ring offered significant influence over the efficacy of the catalyst: the electron donating groups offer a better handle of modification of the electronic properties of the iron center, but the electron withdrawing groups increased the catalytic activity of the complex. In this presentation we introduce a second pyridine ring to the macrocycle skeleton, which includes a second position for modification, and compare the activity of this new RPy2N2 iron complex series to the previous RPyN3 series. Yields within this new series of iron complexes will be compared along with characterization of the respective complexes to understand what properties mitigate reactivity.

Oxidative stress is caused by the accumulation of reactive oxygen species (ROS) in the body and is a key player in many maladies, including neurological diseases like Parkinson’s and Alzheimer’s disease. Superoxide dismutase (SOD) enzymes are capable of transforming the common ROS molecule superoxide (O2-) into less toxic species such as H2O2 or O2, thus protecting the body from harmful reactions of superoxide. Synthetic metal complexes show promise as SOD mimics and can be effective alternatives to therapeutic dosing of SOD enzyme for oxidative stress. In this work, we present a series of 12-membered tetra-aza pyridinophanes (Py2N2) and the corresponding copper complexes with substitutions on the 4-position of the pyridine ring. The SOD mimic capabilities of the Cu[Py2N2] series were explored using a UV-Visible spectrophotometric assay. Spectroscopic, potentiometric, and crystallographic methods were used to explore how the electronic nature of the 4-position substitution affects the electronics of the overall complex, and the complex’s activity as a SOD mimic. This work is an initial step toward developing these Cu[Py2N2] complexes as potential therapeutics for neurological diseases by mimicking SOD’s capabilities and protecting the body from oxidative stress.

The therapeutic potential of macrocycles provides a tantalizing opportunity in drug discovery. The design criteria, such as solubility properties, for macrocycles is only beginning to be understood. One of the significant limitations to such investigations is the synthetic challenge that macrocycles provide and the need for comparison across similar molecules. This study describes the creation of a library of macrocycles to probe and ultimately to engineer partition coefficients. Recently, the quantitative dimerization of monomers to yield 24-atom macrocycles has been described. Historically, a trichlorotriazine is substituted with BOC-hydrazine, an amino acid, and an auxiliary amine (which has been limited until this point to morpholine or dimethylamine). Subsequently, an acetal is installed and treatment with acid results in quantitative dimerization to form macrocycles. To increase the efficiency of synthesis in this study, the acetal is installed prior to the auxiliary amine—the point of divergence. Here, five auxiliary amines were installed to give five monomers. These five monomers were combined in equimolar amounts and treated with acid to induce dimerization to yield five homodimers and ten heterodimers. The octanol:water partition coefficients of these molecules reveal a compensatory effect of substitution. That is, at pH 7, the partition coefficients of the heterodimers lie between the values of the corresponding homodimers. At this pH, the logP ranges between 1.9 and 4.3, indicating that relatively small molecular changes result in large variation in the logP of these macrocycles. The ability to engineer one property—the partition coefficient—suggests that a secondary property—shape—is conserved, a hypothesis borne out by NMR spectroscopy.

Asphaltenes constitute the heaviest, most diverse, and most chemically unresolved component of petroleum crude oils. Asphaltene mixtures are structurally complex, containing thousands of distinct species with a broad range of molecular weights, functional groups, and aromaticity. The structural diversity of asphaltenes, along with their tendency to aggregate, has hindered a complete understanding of the asphaltene component of crude oil. Modern asphaltene studies have deciphered hundreds of individual asphaltene structures through atomic force microscopy (AFM). The structural diversity and expanding chemical knowledge of asphaltene structures necessitates a way to store and easily retrieve and analyze this information. Additionally, much remains unknown about the connection of these imaged structures to ensemble properties of asphaltenes in crude oil. Herein, we address these two points via creation of a database of 69 published asphaltene structures. Quantum chemistry calculations are run to determine molecular properties of these individual asphaltenes and are stored on the database. These properties include molecular weight, solubility, aromaticity, dipole moment, and HOMO-LUMO gap. The database is exploited to generate graphs—such as the UV-Vis absorbance spectrum—using these computed properties to allow for a more complete chemical description of the ensemble properties of asphaltene mixtures. Our computational predictions give a more complete chemical description of previously determined individual asphaltene structures and help contextualize them with respect to their ensemble properties in crude oil.

Although chromatography is a reliable purification method in protein downstream processing, it has several limitations such as loading capacity, scalability and operation costs. These are important drawbacks especially for proteins generated from cell cultures with a high yield. Protein crystallization, which does not suffer these limitations, is regarded as a promising alternative to chromatography for protein purification. However, since protein crystallization is a complex not-well-understood process, protein crystals are often produced at low yield and with poor reproducibility. Thus, its implementation in protein purification protocols remain challenging. In our lab, we designed a new strategy for enhancing protein crystallization from metastable protein-rich droplets generated by liquid-liquid phase separation (LLPS). This strategy is based on the use of two additives; the first additive is needed to induce LLPS in protein aqueous solutions, while the second additive modulates the ability of protein-rich droplets to produce crystals. A protocol for determining yields of LLPS-mediated protein crystallization was also developed. This poster reports our experimental results on yield of lysozyme crystallization in the presence of NaCl (0.15 M) as an LLPS inducer and 4-(2-hydroxyethyl)-1-piperazineethanesulfonate (HEPES) as a modulator. Our results show that addition of HEPES (0.10 M) significantly boosts lysozyme crystallization yield from ≈5% (no HEPES) to 92%. The effect of temperature and incubation time on the yield of protein crystallization yield was also investigated. Our results reveals the key role of LLPS in enhancing protein crystallization.

As of the year 2022, over half of the world’s population lives in cities.​ Large-scale movement into urban environments has inevitable effects on the urban landscape, and in turn has negative effects on the environment. Central Texas is home to the state’s capital city of Austin. With the Colorado river running though the city and an estimated 300 days of sunshine a year, Austin has become a hotspot for urban growth ​.​ Since the 2020 census, Austin’s population has increased by 12,547 residents, with a growth rate of 1.3%, making Austin the 10th largest city in the country. The greater metropolitan Austin area gained nearly 63,000 residents between the years of 2021 and 2022​. In the face of tree removal due to development and climate hazards, cities are losing vital ecosystem services provided by urban forests. For this project, I will be studying how tree removal in the city of Austin affects Land Surface Temperature (LST). The purpose of this research is to examine the influence of tree removal on urban heat. Given the importance of trees to human health in highly urbanized areas, understanding how forest loss impacts urban heat and affect local microclimates will help urban planners, foresters, developers, and municipalities implement sustainable urban forest programs to safeguard human health. By exploring the relationship between urban deforestation and heat, this research contributes to the growing body of literature on urban forests and microclimates and provides information to support the conservation of urban trees.

Urbanization disrupts local climates by replacing natural land cover with impervious surfaces. These surfaces such as concrete and asphalt retain more heat than vegetated cover, therefore, putting these areas at risk for the urban heat island effect. This is when urban areas become significantly hotter than outlying areas and exhibit high temperature anomalies, therefore, putting its residents at risk. Another contributing factor is anthropogenic emissions of greenhouse gases from industries and automobiles. The purpose of this research is to assess areas vulnerable to the urban heat island effect in Dallas County, Texas by looking at the heat severity index (The Trust for Public Lands) and land cover data (NLCD 2021). This study aims to provide insights for planning and policies that enhance resilience to urban heat island risks in Dallas County.

Environmental education is gaining popularity and recognition as a critical strategy to reduce environmental harm, biodiversity loss, and habitat degradation. Education has been identified as a top factor contributing to people’s willingness to engage in environmentally positive conservation behaviors. Non-formal learning institutions such as zoos and aquariums have the unique ability to create and engage learned in species specific education programming. Species-specific education programs can generate high public appeal and contribute to overall environmental conservation outcomes. Research on nonformal environmental education is limited, but most often reports that short-term or single experiences may not be successful in increasing knowledge or contributing to behavior changes. The purpose of this research is to assess the perceptions of educators at non-formal institutions about the success of their conservation education programs. To do this, we conducted a mixed-methods study with educators at marine conservation centers to report on their perceived strengths, weaknesses, opportunities, and threats of education programming as well as on how they define and measure their program success. Our results revealed that educators believe their short-term education programs can be impactful and report on the factors that must be considered to maximize successful program outcomes.

Across the U.S. there are 1335 Superfund sites that range from abandoned mines to old military bases that pose serious risk to the public if not remediated properly. The Tar Creek Superfund site, located in Picher, OK, is one example which could contaminate downstream water supplies via contaminated water and sediment due to the heavy metals, such as Cd and Pb, left behind from the mining activities. This study seeks to determine if the ongoing remediation is effective at Tar Creek which is located within the Tar Creek Superfund site, and whether contaminated sediment is migrating downstream through the watershed.