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Decadal development of CREST hydrological model family: review, improvements, applications, and outlook
Get PDFA hydrological model is an indispensable tool in Earth system science and engineering operations to understand, predict, and manage water resources on Earth. The Coupled Routing and Excess Storage (CREST) model, released in 2011, is one such to simulate distributed hydrologic states and fluxes at variable scales. Over the last decade, CREST model has been actively under development and applied by different sectors to tackle water-related problems worldwide. This dissertation is dedicated to expanding the capacity of CREST model from three main fronts: (1) hydrologic data, (2) model development, and (3) applications. To start, the decadal development and applications of CREST model family were reviewed to lay the foundation for my contribution (Chapter 1). First, uncertainties in hydrologic input data were evaluated comprehensively for three state-of-the-science precipitation datasets derived from in-situ instruments, ground weather radar, and satellites during extreme events (Chapter 2); then a 120-year CONUS-wide flood database was compiled into a unified format as a validation source for models and hydroclimatic research (Chapter 3). From the model development front, a Hydrologic&Hydraulic (H&H) framework was developed to empower flood inundation mapping capacity for CREST (Chapter 4); furthermore, the re-infiltration, an important yet often ignored hydrologic process during the flooding period, was incorporated to improve the more realistic rainfall-runoff modeling representation (Chapter 5). To further improve the model efficiency, a vector-based CREST model was developed that can achieve 10x speedup for a continental-scale simulation, as well as improved model accuracy (Chapter 6). Finally on the model application, the high-resolution CREST model was applied in quantifying future US floods in a warmer climate: flood flashiness is becoming 7.9% higher for the continent (Chapter 7); and extreme rainfall and floods are becoming more frequent, widespread, and less seasonal (Chapter 8). The final Chapter 9 summarizes the contributions to the CREST model family development, outlooks, and general remarks for advancing our understanding of hydrologic science and engineering
A Multidimensional Analysis of an Anomalous, High-Impact, Early-Season Ice Storm in Oklahoma
Get PDFBetween 26 to 28 October 2020, an anomalous, high-impact, and early-season ice storm affected much of Oklahoma. This was the first time the National Weather Service (NWS) Forecast Offices in both Norman and Tulsa had issued an ice storm warning during the month of October and the event is the earliest ice storm in the last 40 years. Overall accumulations were consistent with past ice storm events, but the early season nature of this event led to higher impacts due to increased surface area for accumulations on trees that retained leaves from the growing season. This resulted in branch failures, many downed powerlines, and widespread power outages. Due to the early-timing and severe impacts the goal of this study is to investigate the evolution of the event and identify critical physical processes. First, the synoptic-scale and mesoscale features associated with the event were examined. At the synoptic-scale, a 500 hPa Alaskan ridge, ample 700 hPa moisture transport from the eastern Pacific Ocean region, and the progression of cold 850 hPa temperature anomalies from Canada were all noted 14 days before ice storm onset. At the mesoscale, deep-tropospheric ascent contributed to the significant, localized heavy precipitation across central Oklahoma that was collocated with an anomalous, shallow cold air mass. Second, the October 2020 ice storm was compared to 12 past ice storms in Oklahoma that occurred between 1996 and 2017 to investigate whether the synoptic-scale patterns of an early-season storm differ from normal winter season events. The results yielded similar overall patterns, however, the magnitude of anomalies was generally greater for October 2020 than other past cases. Finally, a potential predictability signal was identified where the geopotential height pattern of past ice storms exists simultaneously with cold 2-meter temperature anomalies over much of the CONUS spanning up to two weeks before event onset
UCO Academic Calendar 2022-23
No full textNoAnnual publication of the University of Central Oklahoma's academic calendar with the official semester schedule, break times, and office closures for the designated school year along with a tentative calendar for the following school year. The calendar is prepared by the University Registrar who submits the calendar to the state regents for approval. This version of the calendar is published each summer by University Communications and distributed to campus offices
Forecasting landslide events in eastern Oklahoma and western Arkansas using empirical methods and statistical machine learning methods
Get PDFUnderstanding the trend of landslide occurrence in eastern Oklahoma and western Arkansas is crucial to the human and social development of the region. Studies suggest rainfall is one of the major landslide triggering mechanisms in the area. However, the association of landslides and rainfall is yet to be fully understood. Here, we analyze rainfall patterns at numerous landslide locations to better characterize the major rainfall conditions that can trigger landslides in the study area. The rainfall-landslide association was determined based on empirical threshold analysis and statistical machine learning approaches. The empirical threshold curve implemented aligns with similar curves developed for regions around the globe.
The developed empirical threshold captures 95 % of the landslide events above the threshold but fails to discriminate over half of non-landslide rainfall events from the landslide rainfall events. The empirical threshold trend also indicates that a small rainfall intensity can trigger landslides in the region.
Five machine learning approaches including K-nearest neighbor, logistic regression, random forest, gradient boost classifier, and voting ensemble classifier were used to determine important rainfall conditions that can trigger landslides. Rainfall features such as rainfall intensity, cumulative rainfall and antecedent rainfall conditions were integrated as input features for the models.
The ensemble classifier model correctly predicted all landslide events in the test dataset with a recall of 100%. The two–week antecedent rainfall data is ranked as the most important feature for forecasting landslide occurrence. Results from this study can be used in developing a landslide early warning an forecasting system as well as in making decisions for hillslope and natural resources management
A Multifaceted Approach to Reptile Conservation from Taxonomy and Systematics to Microbial Ecology
Get PDFRoughly one in five reptile species globally is threatened with extinction as of 2022. Further, nearly 15% of described reptile species are considered Data Deficient by the IUCN and their conservation status has not yet been evaluated. Many of the world’s 11,500+ known reptile species are in dire need of protection and others must first be described in the scientific literature to assess initial threats and potential conservation needs. For my dissertation research, I aim to contribute to ongoing reptile conservation efforts from several different angles. First, I help to better document the world’s reptile biodiversity by describing novel species of geckos from the Philippines. Next, I examine gut microbial ecology in Philippine gekkonids to evaluate the roles of ecoevolutionary forces in shaping host-associated microbiomes. Finally, I study microbial compositions in two different reptile conservation translocation programs to determine how microbiomes respond following host introduction to novel, wild habitats. These studies expand our understanding of reptile biodiversity and help to improve methodologies used for applied reptile conservation.
In Chapter One, I use museum vouchered specimens to study a little-known group of geckos from the Philippines, Scaly-toed geckos of the genus Lepidodactylus. I use both morphological and molecular tools to analyze hundreds of gecko specimens collected throughout the Northern Philippines. In doing so, I identify four new species of Scaly-toed geckos and describe them formally in the scientific literature. I highlight remaining taxonomic uncertainties in the L. yami-balioburius clade and stress the need for additional studies to better understand Lepidodactylus diversity in the region. The description of these four species adds to our understanding of Philippine herpetofaunal biodiversity and lays the groundwork for future threat-assessments to evaluate the status of these previously unknown lizards.
In Chapter Two, I examine host-associated gut microbial communities in multiple gekkonid genera and species, with implications on the adaptive capacity of Philippine gekkonids to changing landscapes. I use cloacal samples collected in the field from nine gecko species to better understand the ecoevolutionary forces that influence gut microbial assemblages and whether historical or contemporary factors may shape such compositions. I identify microbial assemblages specific to each host species and note marked variation among conspecifics at distinct sampling sites, indicating that host locality influences gut microbiomes strongly. I document an interesting trend where individuals grouped as widespread and microendemic in their range tendencies regardless of host species identity display significant differences in alpha and beta diversity metrics examined. Such findings suggest certain species may have differing adaptive capacities to persist in novel or altered habitats.
In Chapter Three, I use these same microbial ecology tools to assess how gut microbial communities in both captive and wild Fijian crested iguanas (Brachylophus vitiensis) differ and how microbiomes respond in captive-reared hosts (e.g. those raised ex-situ in conservation-based facilities) after they are released into the wild. I use both cloacal swabs and fecal samples to establish an initial understanding of gut microbiomes in this IUCN Critically Endangered species. I find significant differentiation in gut microbial community composition and structure between captive and wild iguanas in both sampling schemes. Two months after captive-reared animals are released from captivity to native habitat, I show that microbial communities recovered from cloacal samples closely resemble wild counterparts. Microbial communities in fecal samples from these same individuals, however, remain significantly distinct from wild conspecifics. Interestingly, we also collected fecal samples from lizards reintroduced two years prior and which show microbiomes indistinguishable from those in wild lizards. These results indicate that captive upbringings can lead to differences in microbial assemblages in captive-reared iguanas compared to wild individuals and such differences may persist for a time even after host reintroduction. This investigation highlights the necessity of continuous monitoring of reintroduced animals in the wild to ensure successful acclimatization after release.
Finally in Chapter 4, I again evaluate microbial compositions in reptiles from a reintroduction and translocation program. I analyze fecal samples from Texas horned lizards (Phrynosoma cornutum) raised at the Oklahoma City Zoo and Botanical Garden and released onto Tinker Air Force Base. I do this to identify differences in gut microbial communities between captive-reared and wild lizards and to assess whether gut microbiota in reintroduced Texas horned lizards shift to closely resemble wild counterparts following release. Within three months of reintroduction, translocated Texas horned lizard microbiomes were substantially more similar to wild counterparts than they were while housed in captivity. These results suggest reintroduced animals from captive-rearing and release programs have the capacity to rapidly alter gut microbiota to mirror microbiomes found in naturally occurring host populations. This study offers promising signs for the plasticity of microbiomes in reintroduced hosts and lays important foundations for continued evaluations of microbiomes and their impacts on an animal translocation program
Desiderium
Get PDFDesiderium is a collection of poetry composed with the aim of investigating loss through the primary lenses of grief and addiction. The poems housed in this collection attempt to navigate that opaque, precarious experience of developing an alcohol addiction/dependency while coming of age, and many of these poems specifically address the intersection of addiction, youth, and great tragedy. My work draws inspiration in storytelling technique from poets such as Ada Limón, Tracy K. Smith, and Maggie Smith. To write coherently and honestly about addiction, Kaveh Akbar’s Calling A Wolf A Wolf and sam sax’s madness were my foremost guides and influences. For my poems about grief, Mary Jo Bang’s Elegy was paramount; loss is naturally a heavy subject, and Bang’s work deftly demonstrates how grief can be written without the sacrifice of levity. The female body serving as one of my book’s foremost motifs, I have followed poets such as Natalie Diaz and Limón in my attempts to complicate how the body and the female sexual experience are transcribed. The greatest struggle I faced in the construction of Desiderium was in arranging the poetic order to align with the arc of my speaker in a way that feels purposeful and is coherent to the reader. Her journey is one that begins in a place of questioning and resistance in the first half, and ends in a place of more active acceptance and accountability for her life and her choices in the second. Ultimately, Desiderium is a record of young adulthood from this writer’s unique perspective, an attempt to make sense of fact, memory, and that barely perceptible space where the two intersect
Harnessing metal carbenoids to assemble spirocycles and glycans
Get PDFWithin the realm of drug discovery more intricate, rigid small molecules exhibit higher potencies as drug leads and candidates. This is because molecules with three-dimensional features such as stereochemistry and bond saturation have increased binding specificities, decreased toxicological liabilities, and favorable pharmacological properties. Natural products, due to their structural complexity, have historically established the blueprint for drug discovery, inspiring the cores or complete scaffolds for most pharmaceuticals available today. As a result, over 50% of available drugs are either natural products or their derivatives. While natural products have historically served as trailblazers for the pharmaceutical industry, in the past twenty years drug-discovery programs have de-emphasized natural products in favor of high-throughput screening of synthetic chemical libraries. This shift has been met with diminishing returns, as these changes have led to an average ‘hit rate’ of >0.001% for pharmaceutical screenings of synthetic chemical libraries. Resultantly, there has been a resurgence in the belief that natural product-based drug design is the most practical model for future drug discovery efforts. Therefore, there is a need for convergent methods to access complex cores to sustain these early discovery programs, as often trivial differences in substrates lead to vast differences in site-binding and drug efficacy.
There are several challenges associated with natural product-based drug design, however, the most glaring is the lack of low-cost, efficient methodologies to access privileged natural product-like cores. This dissertation addresses these issues with two primary foci: 1. The implementation of carbenoid-initiated reactions to form complex, natural product-like cores in efficient transformations; and 2. the utilization of metal catalysts for highly specific transformations. While my preliminary studies feature precious metal catalysts, the continuation of my research features Earth-abundant catalysts.
These focuses have converged for the development of methodologies surrounding two small-molecule frameworks: spirocycles and carbohydrates. Through the implementation of metal-carbenoids, we have developed stereoselective protocols to access these privileged frameworks readily in tandem or cascade strategies. Cascade reactions are multiple synthetic transformations that can occur in a single reaction pot, thereby truncating long reaction sequences into a single step. These reactions reduce the number of overall steps necessary to synthesize the desired compound while facilitating the rapid generation of structural complexity from simple starting materials. Likewise, multiple reactions can be completed in a single flask, which negates the need for the isolation of intermediates, thereby reducing the total cost of synthesis. The work herein details cascade sequences that can be utilized to access both scaffolds
Isolation, characterization, and annotation of a novel mycobacteriophage Eaglepride
Get PDFBacteriophages (phages) are obligate intracellular parasitic viruses that infect bacterial host cells. They are the most abundant biological entity on the planet, with an estimated 1031 viral particles in the biosphere. Bacteriophages play various positions in the biosphere by modulating evolutionary and ecological trends in the local and global microbial communities. These roles include controlling the global bacterial host populations through lytic infections, which are critical for biomass turnover by the lysis-mediated release of nutrients from the microbial biomass into the ecosystem. In marine environments, phages play a crucial role in the biogeochemical cycling process of bacterial species. Phage therapy is an important aspect of bacteriophage research due to the phages' narrow host range and inability to infect eukaryotic cells. The use of phages to control bacterial infections is medically relevant due to the rise of antibiotic-resistant bacteria and the adverse side effects of other forms of therapy. Mycobacteriophages can infect Mycobacterium genus hosts. Mycobacterium smegmatis mc2155 (M. smegmatis) was utilized to isolate mycobacteriophages due to its non-pathogenic and rapid growth properties. The mycobacteriophage Eaglepride was isolated using an enriched soil sample from Ashburn, Virginia (39.014667 N, 77.515417 W). As the soil sample was collected from Eagle Ridge middle school, it was named Eaglepride. The isolation of Eaglepride on host bacteria-seeded 7H10 agar plates produced clear, transparent plaques that were 3 mm in diameter. Electron microscopy imaging of the phage showed a Siphoviridae morphology with a tail length of 175nm, tail width of 20nm, and a head diameter of 55nm. Eaglepride is a temperate phage, capable of using the lytic and lysogenic life cycle. Eaglepride had stable growth at temperatures below 60oC and pH between 6 and 8. Genome annotation showed Eaglepride to be most closely related to phages in the A clusters and A10 subcluster. Eaglepride has a total genomic length of 50,926 bp and a GC content of 64.9%. Eaglepride has 88 open reading frames (ORFs), and the annotated genome sequence is in the GenBank database with an accession number of MZ322017. Eaglepride is not a good candidate for phage therapy due to its narrow host range and its utilization of the lysogenic life cycle
The Effect of Iron Fortification of Lentils on Blood and Cognitive Status among Adolescent Girls in Bangladesh
Get PDFIron deficiency is the world’s most common nutrient deficiency according to the World Health Organization. Iron deficiency is especially prevalent in undeveloped countries and rural areas. A double-blind, cluster-randomized design was used among 359 10-17 year old Bangladeshi girls in a three arm trial. Iron-fortified lentils, non-fortified lentils, and no lentil (usual intake) were served to the girls over 4 months with a 100% compliance rate. Blood biomarkers and cognition were assessed using ANCOVAs with group as a factor and age as a covariate. Participants in the fortified lentil condition showed better blood iron status at endline (Hb, sFt, sFtR, TBI) than the other groups. The fortified lentil group also performed better on cognitive measures. Implementing iron-fortified lentils into rural areas may be an effective way to protect against cognitive deficits associated with iron deficiency.
Keywords: iron deficiency, anemia, cognition, biomarkers, Bangladesh, adolescen
Life history strategy and anxiety during the COVID-19 pandemic
Get PDFLife history theory (LHT) describes how animals evolve to maximize reproductive fitness in relation to their environmental conditions. Species fall along a continuum based on whether they tend towards a slow life strategy or a fast life strategy. A key factor that underlies the strategy adopted is the uncertainty of the environment (stable and predictable or uncertain and hostile). The COVID-19 pandemic has been an unprecedented event producing very high levels of uncertainty on a global scale and consequently, varying levels of anxiety in individuals. The goal of this study was to determine whether life history strategy can be used to predict individuals’ experiences of anxiety during the pandemic. It was hypothesized that slow life strategists would experience more anxiety due to the unprecedented nature of the pandemic compared to fast life strategists who are more used to uncertain environments. Participants were first assessed on their life history strategy. An experimental manipulation was used to prime half of the participants to engage in thoughts about the COVID-19 pandemic while the other half experienced a calming stimulus. State and trait levels of anxiety were measured subsequently. Hierarchical multiple regression was used to analyze the relationship between the variables. It showed that while everyone who experienced the COVID-19 prime had higher scores on the state anxiety scale, slow life strategists were less stressed in this condition compared to fast life strategists. No interaction effects were observed. While the results did not appear to support the research hypothesis, there was an overall relationship between LHT and anxiety. These findings contribute to the life history theory framework being developed as a model to explain human behavior in the context of evolutionary psychology