Three b-branch substituted macrocycles featuring a b-branched amino acid linked acetal, a trans-hydrazone, and dimethyl amine were synthesized via acid condensation to yield homodimer macrocycles near quantitative yield without need for further purification. Previous attempts at the dimerization of triazine monomers utilized glycine or b-alanine that do not contain steric bulk. Here, L-valine, L-threonine, and L-isoleucine were used to probe the effects of steric bulk upon macrocycle formation. The resulting macrocycles are symmetrical species that are characterized by 1H-NMR, 13C-NMR, 1H-COSY spectroscopy, and 1H-rOesy spectroscopy. The symmetrical macrocycles containing valine exists as one species while threonine and isoleucine macrocycles exist as two isomers in a 9:1 and 6:4 ratio respectively. All three macrocycles exist as one rotamer state out of four possible. The minor isomer of the threonine macrocycle has an inconclusive rotamer state where the isoleucine macrocycle shows the same rotamer state as the major isomer. Well-tempered MetaDynamics Simulations tell us the rotamer state seen in the rOesy favors a folded state in all cases with barriers to interconversion decreasing as size of the side chain increases.

Cancer is a disease worldwide, and every year millions of people are diagnosed with it. Platinum compounds play an important role as anticancer agents. Their ability to bind to DNA in the nucleus (by a process known as intercalation within DNA base pairs) result in DNA damage and cell death. Unfortunately, these platinum-containing compounds lack specificity toward cancer cells and attack normal healthy cells that results in significant side effects as a consequence (loss of hair, nausea, among others).
Drug carriers (inert structures that house a given drug) that can deliver relatively large amounts of one of these drugs in a small volume (which are often chemically metastable) with some degree of specificity toward the tumor (thereby sparing the healthy cells) are clearly desirable. Our research group has developed a straightforward method to produce a well-defined nanoscale drug carrier known as silicon nanotubes (SINTs), along with a way to incorporate platinum on their surface using (3-Aminopropyl) triethoxysilane (APTES) as a functional arm. These silicon nanotubes have attracted great attention in applications relevant to diagnosis and therapy, owing in part to its biocompatibility and biodegradability in cells.
Once inside the cell, platinum is released slowly, thus allowing an interaction with DNA. Our previous results using this technology showed significant toxicity on a type of cancer cell known as HeLa. While these findings are promising, specificity has not yet been achieved.
Cancer activates signaling pathways that translates on overexpression of specific proteins/receptors. Particularly, folate receptors (FR) are present in 90-98% of ovarian, prostate, uterus, breast, as well as some adenocarcinomas. FR expression is very limited in normal cells and generally not accessible to blood flow which makes it a suitable and promising system to target cancer. These receptors are glycopolypeptides that present a high affinity for folic acid (FA). We propose to incorporate folate to our silicon-based Pt nanoparticles to enhance selectivity.
A viable strategy has been identified, involving the conjugation of a molecule known as glutathione to act as a linker to the surface of the silicon-based platinum nanoparticles through N-Hydroxysuccinimide (NHS) activation, followed by substitution with folic acid. This presentation will highlight some of our recent progress in this approach.

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.

Small molecular probes, dyes with photophysical properties correlating with various environmental physical properties, such as polarity, pH, viscosity, and temperature, are widely used in various areas of analytical, biological, and material sciences.

This poster will describe spectroscopic behavior of pyrrolyl-squaraine dyes in various types of media (i.e., molecular, ionic and deep-eutectic solvents, and micelles) using a variety of spectroscopic techniques (i.e., absorption, fluorescence, nuclear magnetic resonance and circular dichroism). Some aspects related to the synthesis of these dyes will be presented as well.

Due to the high demand of proteins in the pharmaceutical and biotechnological fields, the number of available proteins obtained through DNA recombinant techniques has significantly increased. The high demand for protein production has motivated a need for more efficient and sustainable methods for protein purification in downstream processing. Currently, chromatography is the primary method used in protein purification. However, it is generally regarded to be expensive and cannot be easily applied to large amounts of protein raw materials.
Preparative protein crystallization is regarded as a promising alternative for protein purification as it does not suffer the limitations of chromatography. However, protein crystallization is a complex, not well understood process. Hence, its implementation requires extensive crystallization screening with moderate success. In this poster, a new strategy for enhancing protein crystallization from metastable protein-rich droplets generated by liquid-liquid phase separation (LLPS) is outlined. This strategy requires the use of two additives. One additive promotes LLPS (inducer), and the other additive (modulator) alters the composition of droplets and their thermodynamic stability. This strategy is supported by our recent work on lysozyme in the presence of NaCl (inducer) and 4-(2-hydroxyethyl)-1-piperazineethanesulfonate (HEPES, modulator).

Transparency in business operations has increased across industries as consumer demand for companies to share their sustainability practices has expanded. Because of this, businesses have begun to reinvigorate earlier operational goals that involved actions to improve environmental protection, social equity, or economic stability to align with the three conceptual pillars of sustainability – economy, society, and environment. The purpose of this research is to add to the expanding body of scholarly work investigating methods for operationalizing sustainability research and build on a method for visualizing and analyzing the extent to which sustainability practices align with each pillar of sustainability. To illustrate this method, we examined the websites of 164 manufacturing companies that have their headquarters in one of Texas’s four largest metropolitan statistical areas (MSA; i.e., Austin-Round Rock-Georgetown, Dallas-Fort Worth-Arlington, Houston-The Woodlands-Sugar Land, and San Antonio-New Braunfels). We used a quantitative content analysis approach to document occurrences of sustainability practices related to each entity’s business operations. We sorted these observations into one of the three pillars of sustainability and then visualized the occurrences across the four MSAs. The results show how location can influence manufacturer’s sustainability efforts, and that the integration of sustainability practices remain nascent despite consumer demand for transparency and sustainability.

It is generally acknowledged that natural resources are preferentially selected by wildlife and it is only when these resources are unavailable or limited that a species will seek a less preferable option or alternative. While the use of anthropogenic structures and features by wildlife in disturbed habitats or urban environments is well-documented, the use of such resources in natural and semi-natural habitats is not. To address this, we explored the importance of artificial water sources for bats in a semi-natural habitat. We conducted acoustic monitoring surveys at two swimming pools at tourist lodges on the Amakhala Game Reserve in South Africa from 2018 to 2021 and behavioral observation surveys in June of 2021. From the data collected, we determined species-specific activity within proximity to the pools, foraging activity (identified by approach phase calls and feeding buzzes), and drinking activity (identified by the occurrence of drinking buzzes). Seven of 23 locally known species have been identified at the swimming pools, at which both foraging (~1% of calls) and drinking activity (~5%) has been recorded. This study provides insights into how anthropogenic features could be of value to wildlife in a semi-natural habitat.

The 1.2 Ga Barby Formation located in SW Namibia is comprised of basaltic andesites and shoshonites from oblique subduction in a volcanic arc setting. Recent mapping and whole-rock geochemistry within the Barby Formation has been completed by previous TCU graduate students. Clinopyroxenes (CPX) from samples collected during these studies were analyzed using an Electron Microprobe (EMP) at Fayetteville State University, North Carolina. Data collected from CPX phenocrysts corresponds with previous findings that the samples can be divided into two groups. Group 1 samples show an enrichment in rare earth elements (REE) and light rare earth elements (LREE) Th, Zr, La/Yb, Nb, with a smaller Ti anomaly as compared to Group 2 (Lehman, 2019; Orhmundt, 2020). CPX phenocrysts within Group 1 have higher TiO2 wt% concentrations. Differences between the two groups are attributed to different source rock compositions and partial melting (Lehman, 2019; Orhmundt, 2020). Mineral compositions and cation ratios from EPMA data were also used to determine geothermobarometric conditions of the formation’s magma plumbing system. Single-clinopyroxene thermometry and barometry equations from Wang et al. (2021) and Purtika (2008) were utilized in this study. Wang et al. (2021) calculations resulted with average pressures between 1-3 ± 1.5 kbar and average temperatures between 1100-1200 °C. Purtika (2008) calculations resulted with overall higher pressures averaging at 3-5 kbar and slightly hotter temperatures at 1200 ± 50°C. Overall temperatures are higher than what would be expected in the basaltic andesitic system and variations could be due to the low-grade metamorphism the area has experienced that has affected the geochemistry.

Subsidence is a downward sinking of earth materials that creates a large or small circular surface, but it may produce linear or irregular failure patterns. The highly dissolved calcium carbonate or evaporite rocks allow acidic rainwater to permeate its strata. Near or underlying rock can easily be dissolved in water and create space and caverns underground, making a sudden catastrophic collapse of the land surface. Highly soluble bedrocks are a widespread geologic phenomenon in the West Texas Permian Basin. The majority of the area has been impacted by the subsurface dissolution gypsum layers, which is a cause of the active sinkhole formation from a few meters to 100 m wide. This geohazard has caused damage on infrastructure and civilian property. It can cause environmental problems when it alters the local hydrology. Sinkhole detection using field surveying is expensive, time-consuming, labor-intensive, and not easily accessible, and it might be potentially dangerous for the surveyor. In this paper, I detect, map, and thus analyze anthropogenic triggering factors of sinkholes in Wink, Texas, using open-source high-resolution LiDAR (Light Detection and Ranging) data. Methods involve Generating Digital Elevation Model (DEM), extracting the depressions from DEM, identifying sinkhole boundary contour, and then converting the delineated sinkhole to a polygon shapefile, analyzing the shape and geometric properties. False alarm sinkhole depression eliminates based on the threshold value. Finally, human-induced factors have been investigated.

Distributive fluvial systems (DFS) are cited to be one of the most dominant fluvial depositional systems seen in continental basins. This system can now be defined by five common characteristics seen in many continental basins: 1) channels that radiate from an apex; 2) a channel size decrease downstream; 3) an increase in preservation of floodplain deposits relative to downstream deposits; 4) a decrease downstream in channel grain size; 5) a change from amalgamated channel deposits in proximal areas to more separated and smaller channels in distal areas. DFSs have been heavily studied in the Morrison Formation near the Four Corners of the United States, however, they have not been tested in eastern New Mexico. The above set of parameters are tested in the Morrison Formation in East New Mexico against the Salt Wash DFS to see how the two systems compare.
Completing this study will provide quantitative analysis over a potential ancient DFS with the goal of providing a dataset that can be used to compare with other DFSs. Additionally, analyzing an unknown area of the Morrison Formation will ultimately open up studies to be worked on in the future. Correlating the East Morrison Formation DFS with the Colorado Plateau Morrison Formation DFS will bridge the gap for determining similarities and differences between these exposures and set the stage for future studies. Additionally, this work will also help us better understand the wider Morrison basin and facies distributions within.

The Upper Jurassic Morrison Formation has been extensively studied in the Western-Interior United States since it contains economic resources of uranium, vanadium, and some of the most well-preserved dinosaur fossils in the United States. Covering over 450,000 square miles from southern Canada to New Mexico, the Morrison Formation's enormous extent presents a unique opportunity to understand the processes happening on Earth's surface during the Late Jurassic. Studies of the Morrison Formation have primarily focused on areas where there are large concentrations of the aforementioned economic resources within its strata. The geologic community has largely overlooked Morrison Formation outcrops in northeastern New Mexico compared to the exhaustively studied outcrops in and around the Colorado Plateau. The absence of recent studies in the Morrison Formation in northeast New Mexico provides a chance to explore it with a level of detail unobtainable until recently. This study will undergo a detailed architectural analysis of two to three extensive outcrops of the Morrison Formation in northeastern New Mexico. This Study will do detailed bedding and facies diagrams of these outcrops from drone images to constrain fluvial style and fluvial history of these rocks. Studying the Morrison Formation in a high level of detail will, in all likelihood, produce new information on the climate and fluvial morphology of the environment in the Late Jurassic. With a new detailed understanding of this all but forgotten piece of the Morrison Formation, the groundwork will be laid for the potential to correlate this piece of the Morrison Formation with other understudied or non-correlatable pieces elsewhere across its vast depositional extent and to piece this part of the Late Jurassic fluvial story into the larger puzzle.

Martian meteorites provide us with a window into the processes occurring during the formation and evolution of the terrestrial planets, such as: accretion and differentiation, emplacement and formation of magmatic rocks, the behavior and content of volatile compounds, and the effects of impact events. Here, we present the initial results from a two-phase study on a presumed Martian meteorite, hereafter referred to as NWA X. First, the 800g main mass of NWA X was imaged prior to cutting using 3D laser scans and photogrammetry to produce 3D models of the meteorite’s exterior, and computed tomography (CT) to provide scans of the interior. The main mass was cut and a 175g end piece was donated to the Monnig Meteorite Collection, along with a 5g chip for scientific analysis. In the second phase of the study, we will characterize NWA X in terms of its texture, modal mineralogy, and mineral chemistry. Results from this study will allow us to confirm if NWA X is of Martian origin and, if so, place it in context within the existing dataset for Martian meteorites.

Mesosiderites are a group of stony-iron meteorites that contain roughly equal amounts of core material (metal) and crust (silicates) from one or more asteroid parent body. The core material is predominantly Fe,Ni-metal, with some troilite (FeS), and is found as clasts and/or intimately mixed within the meteorite matrix. Silicate clasts are basaltic or gabbroic in origin, representing different formation depths within the crust, and are predominantly plagioclase and pyroxene. The formation of mesosiderites is not fully understood, but observed features require a three stage process: (1) formation of asteroidal silicate crust; (2) metal-silicate mixing, where molten metal is injected into the solid silicates; (3) deep burial, as reflected by the extremely slow cooling rates of less than 1ºC/My. Mesosiderites are classified by pyroxene content and degree of metamorphism, which focuses only on the silicate phases. That not only ignores half of their mineralogy, but also the third stage of their formational history. Additionally, only 15% of known mesosiderites have been studied in detail. This research aims to 1) investigate five previously understudied and ungrouped mesosiderites and 2) determine if metal within mesosiderites can be used to refine current classification schemes.

Debris flow is a landslide with a quick velocity of displacement that involves risk and damages to life and property. It can be triggered by periods of intense rain usually on steep slopes. Also, a second triggering factor is the influence of wildfire. Wildfire can increase drastically the probability of this type of landslide because the fire burned the vegetation which helps to stabilize the soil and the slope. The research uses geographical information system (GIS) for the development of mapping landslide susceptibility, with a particular interest in the evaluation of areas vulnerable to debris flow natural hazards that may be triggered after a wildfire, with the effects of intensive periods of precipitation. The method has been applied to Montecito city, which was exposed to a massive mudslide in January 2018. The spatial landslide susceptibility response in this study area is correlated to different factors, such as vegetation, lithology, slope gradient, and distance to streams networks which are considered the control of the probability of incidence of a landslide event in this area. Obtained by using the methodology of the multi-criteria decision evaluation (MCE) model. The results obtained from this study indicate that the GIS-based model is valuable and appropriate for the scale used in this study. The model helped to identify areas that still are affected by the wildfire, which can be vulnerable to a new process of debris flow impacting the population closer to the rivers downhill.

The city of Austin and its surrounding area is experiencing tremendous growth and expansion as a consequence of fast urban development and population growth. This has led to increased constructions and other anthropogenic alterations of the environment to accommodate the growing population and economy. These activities, coupled with the natural conditions and forcings, have made areas within the metropolis susceptible to the threats of landslides. The present study aims to identify zones in the study area that are susceptible to the threats of slow-moving creep/slow-slide landslide hazards and understand the factors and processes that control the occurrence of these events through an integrated study approach. This includes: (1) generating a landslide susceptibility (LS) map through a combination of the triggering factors including local geology and tectonic features, land use/cover, elevation/slope, and precipitation; (2) detecting active deformation processes that could lead to landslide failure using Interferometric Synthetic Aperture Radar (InSAR) analysis techniques applied on Sentinel-1 SAR datasets (2015 – 2020) and validated through datasets from campaign GPS surveys and permanent stations; and (3) identify the factors and processes that directly or indirectly constrain the occurrence of the phenomenon through spatial analysis of relevant datasets. Our findings show: (1) the main concentration of vertical displacement (-1 to -6 mm/yr) is around the northern region of the study area; (2) zones with a moderate subsidence rate coincide with urbanized areas (up to -2 mm/yr) whereas pockets of high displacement rates (up to -6 mm/yr) are noted on NW parts; (3) most of the areas experiencing subsidence are underlain by the Comanche Series characterized by alternating beds of harder and softer limestones interbedded with beds of marly/clayey layers, and formations of marine marl, sandstone, and carbonaceous shale from the Gulf Series; (4) there is a high spatial correspondence between areas with high subsidence rates and high LS index; and (5) efforts are currently underway to analyze relevant datasets to determine factors and processes that control the occurrence of the hazard.

Nationally groundwater supplies 30% of the freshwater while within Texas that number increases to 60%. As population increases across the United States, Texas being the 7th fastest-growing state, there is immense pressure on freshwater resources. It is important to monitor the quality of groundwater reservoirs to ensure continuous and sustainable use of these reservoirs for current and future populations.
This study assesses the water quality of all nine major aquifers in Texas, with a focus on investigating the water chemistry change across shallow wells (below 300 feet) in these aquifers. This study used a distributed analysis to extrapolate the pH and Total Dissolved Salts (TDS) distribution across Texas major aquifers and revealed that all the shallow wells exhibit signs of water chemistry change. Decadal analysis of data from the Pre-1960s up to 2016 indicates that the pH of these shallow wells had sudden salinization between 1975-1985, followed by significant acidification from 1985 to 2016, where all aquifers followed this trend with the exception of Carrizo Wilcox in the far East and Hueco Mesilla Bolsons in the far West of Texas. On the other hand, TDS increased consistently statewide.
Added effort will be geared towards finding a correlation between the long-term groundwater chemistry change and the land use/land cover change around the major aquifers of Texas. The results of this project will help to determine the possible origin and causes of the change in groundwater chemistry of shallow aquifers in Texas.

The Austin Chalk is a rhythmically bedded sequence of chalk and marl that represents pelagic to hemipelagic carbonate deposition in the ancestral Gulf of Mexico during the Upper Cretaceous. The Austin Chalk differs from traditional chalk deposits due to its relatively high abundance of clay and volcanic ash. Outcrops of the chalk stretch from north-central Texas to west Texas and surface exposures mirror the subsurface trend of the Ouachita orogen. Deformation of the heavily fractured Austin Chalk is caused by the normal faults associated with the Balcones Fault Zone.
Historically, the Austin Chalk has been exploited as a conventional hydrocarbon reservoir produced from natural porosity and permeability without large hydraulic stimulations. More recently, the Austin Chalk has been explored as a combination fractured and unconventional reservoir, relying on natural porosity and permeability combined with induced hydraulic fracturing to generate new fracture permeability to release hydrocarbons trapped in microscopic pores. In addition to its reservoir properties, much of the city of Dallas is built within the outcrop trend of the chalk. Thus, understanding the properties and deformation features of the Austin Chalk is also important to the construction industry in north-central Texas.
Deformation of the Austin Chalk in Ten-Mile Creek is characteristic of normal faulting seen in platform carbonate sequences. Faults are identified by the presence of slickenlines and fault gouge, and are surrounded by a damage zone defined by synthetic faulting, jointing, and folding. Deformation is concentrated near the fault core and decreases with distance from the fault core. Here, we present a structural analysis of Church of the Nazarene section of Ten-Mile Creek. The mechanical properties of stratigraphic units are quantified using a Schmidt hammer. Fracture parameters, such as fracture density and intensity, are quantified using scanline surveys. Additionally, spectral gamma ray measurements are made in the field using the RS-230 spectrometer. Spectral gamma ray properties are combined with fracture parameters to create an integrated structural and petrophysical analysis.

The Sierra Nevada in California has a rich Cenozoic volcanic history including important arc sequences related to the southern Ancestral Cascades dating as far back as 30 Ma (du Bray et al., 2014). The present study focuses on Pliocene volcanic debris-avalanche deposits in the northern Sierra Nevada that fill paleocanyons west and northwest of Lake Tahoe. The paleocanyons trend west, west-southwest, and west- northwest from an unknown volcanic source to the east (Berkebile, 2003; Harwood et al., 2014). The main objective of this study is to examine petrogenetic relations of the debris-avalanche deposits and obtain isotopic ages for them. Another purpose is to determine if the three debris-avalanche deposits are from the same eruptive event or possibly the result of separate eruptions and multiple source vents. To acquire detailed data for this study, I am using whole-rock chemistry of both major and trace elements, electron microprobe analysis of phenocryst phases, and analysis of melt inclusions for magmatic volatile contents. Isotopic ages will be obtained using 40Ar/39Ar dating. Clinopyroxenes (CPX), orthopyroxenes (OPX), and plagioclase phenocrysts from samples collected have been analyzed using an electron microprobe (EMP) at Fayetteville State University, North Carolina under supervision of Dr. Steven Singletary. Data from these phenocrysts phases will be used to determine geothermobarometric conditions of the parental magma chamber or chambers.

Organic matter, a complex mixture of organic compounds, is responsible for the cycling of global carbon and nutrients in aquatic and terrestrial ecosystems. Understanding the sorption and desorption dynamics of organic matter on mineral surface is then important in determining the mechanisms of carbon, pollutants and nutrients cycling in the environment. This project assess the energetics and dynamics of sorption and desorption of natural organic matter from different sources with 2-line ferrihydrite. To understand how theses interaction occur on mineral surfaces, we studied the sorption and desorption behavior of various fraction of organic matter such as humic acid, fulvic acid, natural organic matter as well as water-extracted organic matter from charred plant biomass. Result thus far show the differences in energy, quantity and the kinetics of sorption and desorption involved in these interactions. The energy and rate involved in the binding and de-binding of natural organic matter with the surface of 2-line ferrihydrite is greater than those associated with charred ashe juniper. Additionally, the energy of sorption and desorption decrease with increasing pH conditions. In contrast, the rate of reaction increase with increasing pH. This presentation will link the chemical properties of organic matter as well as the surface properties of ferrihydrite and their influence on the sorption and desorption dynamics across different environmentally relevant pH conditions.

A flow adsorption microcalorimtery-UVvis spectroscopy method was used to directly measure high temporal resolution energetics and energy dynamics of Adenosine triphosphate disodium (ATP) at the ferrihydrite-water interface. Ferrihydrite is amongst the most reactive and ubiquitous form of Fe-oxide minerals in the geosphere known to exhibit controlling effects on the bioavailability and cycling of nutrients such as Phosphorous. Fe-oxide minerals are known catalysts in the phase transformation from organic phosphate (Po) to inorganic phosphate (Pi) depending on the surface and organic molecule speciation. Interactions of ATP and ferrihydrite at pH 2, 5, and 8 were conducted to quantify the effect of pH on energetics and energy dynamics. At pH 2, 5, and 8 where the speciation of ATP was cation, uncharged, and anion respectively, its interactions with nitrate (NO3-) saturated ferrihydrite were exothermic with 13.8 J g-1, 11.4 J g-1, and 8.7 J g-1 respectively. Nitrate’s interactions with ATP saturated ferrihydrite were endothermic with 13.8 J g-1, 11.5 J g-1, and 45. 4 J g-1 at pH 2, 5, and 8 respectively. Post ATP anion exchange indicated that the interaction of ATP and ferrihydrite decreased by a factor of ≈ 1.8 (6.51 ± 0.38 J g-1 to 3.63 ± 0.23 Jg-1), ≈ 1.6 (0.13 ± 0.01 J g-1 to 0.08 ± 0.02 Jg-1 ), ≈ 2 (0.15 ± 0.05 J g-1 to 0.07 ± 0.02 Jg-1 ) at pH 2, 5, and 8 respectively. In addition to ATP’s speciation and ferrihydrite’s surface charge, differences in interaction energetics and dynamics were attributable to the Pi produced by hydrolysis of ATP. A decrease in post ATP anion exchange suggested partial reversibility by NO3- pointing to inner sphere interactions with ferrihydrite. The presentation will further discuss the molar heats of inner sphere interactions of the ATP and Pi with ferrihydrite at pH 2, 5, and 8.

Beginning in the Late Mississippian to Early Pennsylvanian, southern Laurentia experienced a major tectonic regime change. Progressive closure of the Rheic Ocean and collision between Laurentia and Gondwana along the Ouachita-Marathon fold and thrust belt drove deformation and subsidence within a series of basins along the southern Laurentian margin. Few provenance studies in the Ardmore Basin have been conducted mainly based on facies distribution, and heavy mineral and petrographic analyses. There are two opposing ideas regarding regional sediment deposition; 1.) a transcontinental system with headwaters from the Appalachian Orogen region and minor inputs from uplifts associated with the Ouachita Orogen, and 2.) a dominant transport from a southern source, likely accreted Gondwanan terranes. Here I propose a detailed U-Pb detrital zircon geochronology study to document the provenance of major upper Mississippian (Chesterian) to lower Pennsylvanian (Atokan) sandstones in the Ardmore Basin. I hypothesize that due to increased regional tectonic activity to the east and south, the Ardmore Basin experienced a major source shift from the Late Mississippian to Early Pennsylvanian with sediment transitioning from mature sand, mainly derived from Laurentia, to less mature sediments likely sourced from the Appalachian and Ouachita Orogens and local uplifts. Results of this study will provide critical evidence for the debate between previously proposed transcontinental vs. locally-derived sediment dispersal models, and contribute to the understanding of paleogeography during the collision of Laurentia and Gondwana.

Meander bend theory has been around since Albert Einstein popularized it in the 1920s. Since then, many geologists and physicists have grappled to understand the mechanics and concepts that cause rivers to meander in the ways that they do. Through the years, scientists have learned that bedload, slope, and flow velocity are all major drivers of cutbank erosion and bar building. However, one answer that has eluded scientists to this point is whether bar building (bar push) or bank scour (bank pull) causes meander bend migration. This study aims to analyze meander bend patterns in an 88 Km unchannelized stretch of the Missouri River between Yankton, SD and Sioux City, IA. Landsat images of this stretch over the last 30 years have been processed in remote sensing software to track bank, bar, and channel changes over this span of time. Extensive remote sensing processing (ESRI ArcMap and ArcGIS Pro) and statistical analyses will be performed on the river with respect to bank vs. bar movement, mid-channel bar migration, bar growth, and bar life cycles.

The Red River of the South is a highly understudied fluvial system with limited mapping. Early work, however, did map four fluvial terraces along the flanks of the modern river valley. These terraces record a period of time in which the ancestral Pleistocene Red River was a continent-scale river, sourcing from the Rockies and the volcanic uplands of New Mexico and depositing into the Gulf of Mexico. The ages of these terraces, though, are poorly understood. With these four known terraces, spanning the “terrace zone” (a ~5 km radius from the modern valley), and with surface areas of the terraces ranging between ~3 km2 and ~8.8 km2—there exists the potential to document the deposits of these four distinct periods of lateral migration—as well as to characterize various paleochannels and other fluvial features preserved within these terraces through hand auger sampling.

I aim to track the evolution of the Red River both physiologically and geochronologically, utilizing allostratigraphic methods to reconstruct some of the River’s past through the floodplain’s lithology and optically stimulated luminescence (OSL) dating of preserved terraces. I aim to construct detailed cross-sections of the valley fill by sampling the deposits of each of the various ancient terraces, as well as the modern floodplain, running roughly perpendicular to the axis of the current stretch of the Red River. Ideally, I would encounter paleochannels while drilling so as to potentially assess the features of the paleochannel belt. To maximize the likelihood of encountering paleochannels and related assemblages, I have begun to process and analyze Lidar and satellite data in an effort to identify remnants of these paleo-structures. I will collect sealed samples containing silica grains to send for OSL dating. In doing so, I can ascertain definitive dates on when the deposits associated with specific terraces were laid down.

Mathematical modeling of viral kinetics can be used to gain further insight into the viral replication cycle and virus-host interactions. However, many of the virus dynamics models do not incorporate the cell-to-cell heterogeneity of virus yield or the time-dependent factor of virus replication. A recent study of vesicular stomatitis virus (VSV) kinetics in single BHK cells determined that both virus production rate and yield of virus particles varies widely between individual cells of the same cell population. Here we use the results of the previously mentioned study to determine the distribution that best describes the time course of viral production within the single cells. We determined a list of eight potential distributions that are commonly used in viral kinetics models to fit to each data set by minimizing the sum of squared residuals. The model of best fit for each individual cell was determined using Akaike’s Information Criterion (AICC ). Results of this study show that the distribution that best describes viral production varies from cell to cell. This finding could have further reaching implications for incorporating time-dependent viral production into a standard model of virus kinetics in order to better reproduce the diversity of viral replication that occurs over time within a population of cells.

This report presents a novel approach to increase the detection sensitivity of trace amounts of DNA in a sample by employing Förster Resonance Energy Transfer (FRET) between intercalating dyes. Two intercalators that present efficient FRET were used to enhance sensitivity and improve specificity in detecting minute amounts of DNA. Comparison of steady-state acceptor emission spectra with and without the donor allows for simple and specific detection of DNA (acceptor bound to DNA) down to 100 pg/ul. When utilizing as an acceptor a dye with a significantly longer lifetime (e.g., Ethidium Bromide bound to DNA), multi-pulse pumping and time-gated detection enable imaging/visualization of picograms of DNA present in a microliter of an unprocessed sample or DNA collected on a swab or other substrate materials.

We studied room temperature phosphorescence of tryptophan (TRP) embedded in poly (vinyl alcohol) [PVA] films. With UV (285 nm) excitation, the phosphorescence spectrum of TRP appears at about 460 nm. We also observed the TRP phosphorescence with blue light excitation at 410 nm, well outside of the S0→S1 absorption. This excitation reaches the triplet state of TRP directly without the involvement of the singlet excited state. The phosphorescence lifetime of TRP is in the sub-millisecond range. The long-wavelength direct excitation to the triplet state results in high phosphorescence anisotropy which can be useful in macromolecule dynamics study via time-resolved phosphorescence.