Physical Sciences and Mathematics Commons^™

Ph-Sensitive Chitosan Nanoparticles For Salivary Protein Delivery, Yi Zhu, Lina M. Marin, Yizhi Xiao, Elizabeth R. Gillies, Walter L. Siqueira

Chemistry Publications

Salivary proteins such as histatins (HTNs) have demonstrated critical biological functions directly related to tooth homeostasis and prevention of dental caries. However, HTNs are susceptible to the high proteolytic activities in the oral environment. Therefore, pH-sensitive chitosan nanoparti-cles (CNs) have been proposed as potential carriers to protect proteins from enzymatic degradation at physiological salivary pH. Four different types of chitosan polymers were investigated and the optimal formulation had good batch to batch reproducibility, with an average hydrodynamic diame-ter of 144 ± 6 nm, a polydispersity index of 0.15 ± 0.04, and a zeta potential of 18 ± 4 mV at …

Educating For Sustainable Forestry: Perspectives On The Career Readiness Of New Professionals, Samantha Jones

Education Doctorate Dissertations

This qualitative phenomenological study explored forestry career readiness from the perspective of forestry employers and early career forestry professionals. A virtual focus group interview, individual online interviews, and a review of forestry education documents produced study data. Participants were selected through snowball sampling. Data were analyzed through open and axial coding. Salient themes emerging from this inquiry centered on the dynamic complexity of forestry, field competence, interpersonal skills, and situated learning. Study findings concluded that sustainable forest management required field skills to conduct remote forestry activities and interpersonal skills to negotiate diverse stakeholder interests. Implications for educational practice and recommendations …

Environmental Racism In A Growing City: Investigating Demographic Shifts In Salt Lake City's Polluted Neighborhoods, Emma Jones, Mariya Shcheglovitova

Undergraduate Honors Projects

We aim to contribute to research on environmental racism by asking how relationships between race and hazard exposure change over time. We analyze American Community Survey (ACS) demographic data from 2010 and 2019 to determine whether census tracts with high densities of EPA environmental hazard sites have a growing, shrinking, or unchanging proportion of Latinx residents. We argue that racist planning practices effectively weave environmental racism into the fabric of cities and that cities with growing communities of color must consider how existing spatial patterns of segregation may perpetuate exposure to environmental harms.

Spatial Variations Of Upper Crustal Anisotropy Along The San Jacinto Fault Zone In Southern California: Constraints From Shear Wave Splitting Analysis, Enyuan Jiang, Kelly H. Liu, Yuan Gao, Xiaofei Fu, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To discern spatial and explore possible existence of temporal variations of upper crustal anisotropy in an ∼15 km section of the San Jacinto Fault Zone (SJFZ) that is composed of the Buck Ridge and Clark faults in southern California, we conduct a systematic shear wave splitting investigation using local S-wave data recorded by three broadband seismic stations located near the surface expression of the SJFZ. An automatic data selection and splitting measurement procedure is first applied, and the resulting splitting measurements are then manually screened to ensure reliability of the results. Strong spatial variations in crustal anisotropy are revealed by …

Best Practices In Industry And Cse Senior Design, Conner Hallett

Honors Theses

The widespread use of Agile practices in the software development industry creates the need for new college graduates to be adept in Agile processes and teams. The University of Nebraska-Lincoln’s Computer Science and Engineering (CSE) Senior Design courses gives students an introduction to such processes, but is met with many challenges in doing so, such as time constraints and student inexperience. Following a detailed look at the Scrum Agile framework and its expanded practices in industry, potential improvements for CSE Senior Design’s practice of Agile are suggested. These include the creation of resource forums for students to accelerate the early …

Unprecedented Migratory Bird Die-Off: A Citizen-Based Analysis On The Spatiotemporal Patterns Of Mass Mortality Events In The Western United States, Di Yang, Anni Yang, Jue Yang, Rongting Xu, Han Qiu

United States Department of Agriculture Wildlife Services: Staff Publications

Extensive, severe wildfires, and wildfire-induced smoke occurred across the western and central United States since August 2020. Wildfires resulting in the loss of habitats and emission of particulate matter and volatile organic compounds pose serious threatens to wildlife and human populations, especially for avian species, the respiratory system of which are sensitive to air pollutions. At the same time, the extreme weather (e.g., snowstorms) in late summer may also impact bird migration by cutting off their food supply and promoting their migration before they were physiologically ready. In this study, we investigated the environmental drivers of massive bird die-offs by …

Molten Alkali Halide Salt-Flux Crystal Growth And Physical Property Determination Of Complex Oxides And Chalcogenides Supported By First Principles Density Functional Theory Calculations, Mohammad Usman

Theses and Dissertations

The primary objective of this dissertation is to inform the reader about more thansixty new materials with potentially attractive physical properties obtained via molten alkali halide flux methods as X-ray diffraction quality crystals. Flux crystal growth carries several advantages over other synthetic methods, including low reaction temperatures and straightforward post-reaction workup. This dissertation consists of 11 chapters, including an introductory chapter, which are organized into two parts, each corresponding to the general structure type of the family of oxides and chalcogenides being investigated. Part 1, which encompasses chapters 2–6, is dedicated to the discussion of crystal growth of complex chalcogenides …

Development Of A Liquid Biopsy: Using A Synthetic Lectin Array For The Detection Of Cancer, Mary Grace Hollenbeck

Theses and Dissertations

Cancer is the second leading cause of death worldwide with 9.6 million deaths in 2019. It is well known that early detection of cancer often leads to a better prognosis. However, due to drawbacks associated with current cancer screens (i.e. invasiveness, high false positive and negative rates) new or updated early detection methods are needed. Chapter one overviews current breast, colon, and prostate detection methods and the drawbacks associated with them. Additionally, this chapter presents an alternative detection method that utilizes an array of boronic acid functionalized synthetic lectins. We describe the development and progression of this array and show …

Molecular Basis Of Xenobiotic Metabolism And Resistance In Tetranychus Urticae, Leily Daneshian

Theses and Dissertations

Invasive pest species are a major cause of crop loss around the world and adversely affect the agricultural industry. We are focusing on Tetranychus urticae (two-spotted spider mite; TSSM), which is a polyphagous pest that targets more than 1100 plant species. The TSSM alone causes a loss of roughly $1.6 billion per year globally due to acaricide resistance. It is developing resistance to most acaricides due to rapid growth and reproduction. Therefore, new acaricides are needed to combat TSSM resistance and infestation [1]. To address this problem, four enzymes of TSSM, intradiol ring cleavage dioxygenases, a glutathione S-transferase, a β …

A Spatial Risk Prediction Model For Drug Overdose, Parisa Bozorgi

Theses and Dissertations

Drug overdose is a leading cause of unintentional death in the United States and has contributed significantly to a decline in life expectancy from 2015 to 2018. Overdose deaths, especially from opioids, have also been recognized in recent years as a significant public health issue. To address this public health problem, this study sought to identify neighborhood-level (e.g., block group) factors associated with drug overdose and develop a spatial model using machine learning (ML) algorithms to predict the likelihood or risk of drug overdoses across South Carolina. This study included block group level socio-demographic factors and drug use variables which …

Deep Learning Based Models For Classification From Natural Language Processing To Computer Vision, Xianshan Qu

Theses and Dissertations

With the availability of large scale data sets, researchers in many different areas such as natural language processing, computer vision, recommender systems have started making use of deep learning models and have achieved great progress in recent years. In this dissertation, we study three important classification problems based on deep learning models.

First, with the fast growth of e-commerce, more people choose to purchase products online and browse reviews before making decisions. It is essential to build a model to identify helpful reviews automatically. Our work is inspired by the observation that a customer's expectation of a review can be …

Monitoring Of Carbon Dioxide Injection In The Southeastern United States, Adil Murad Awad Alshammari

Theses and Dissertations

Over the past few decades, measured levels of atmospheric carbon dioxide have substantially increased. One way to limit the adverse impacts of increased carbon dioxide concentrations is to capture and store it inside Earth's subsurface, a process known as CO2 sequestration. This method's success is critically dependent on the ability to confine injected CO2 for up to thousands of years. Establishing effective maintenance of sealing systems of reservoirs is of importance to prevent CO2 leakage. Understanding the nature and rate of potential CO2 leakage related to this injection process is essential to evaluating seal effectiveness and ultimately mitigating global warming. …

A Simulation-Based Study Of Location-Shift Models Under Non-Normal Conditions, Ummay Khayrunnesa Anika

Theses and Dissertations

In this study, we compare ordinary least squares (OLS), generalized least squares (GLS), M- and quantile regression (QR) estimators for a continuous response variable under different scenarios by conducting a simulation study. We assess the performance of the estimators in terms of bias, average distance, mean squared error, coverage probability, and ratio of estimated standard error and empirical standard deviation. OLS estimator performs the best when the errors are homoscedastic normal or homoscedastic but skewed (exponential) having no outliers. GLS estimator shows good comparative results to QR when the errors are heteroscedastic normal or heteroscedastic heavy-tailed (t-distributed). The most satisfactory …

Characterization And Hydrogenation Activity Of Supported Palladium Particles, Narayan Acharya

Theses and Dissertations

In this project, the hydrogenation activity of palladium (Pd) particles supported on different carbon and oxide supports was investigated. Supported Pd particles were prepared using strong electrostatic adsorption (SEA) technique, which is known to produce metal particles with narrow and uniform distribution. The scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), and chemisorption methods were used to characterize the Pd particle size in this project. The Pd particles on different supports were annealed at a specific temperature, and the particle size was studied as a function of annealing temperature. Propylene hydrogenation to propane was conducted in a flow reactor to …

Feasibility Study Of ΛD Elastic Scattering In Data From Photoproduction Off Deuteron, Brandon Steven Tumeo

Theses and Dissertations

Experimental observables for hyperon-deuteron (Yd) scattering are important in the study of the YN interaction and, especially, the YNN three-body interaction. YN scattering experiments are difficult and lacking due to the short lifetime of hyperons. Currently, there is a very limited database for YN elastic scattering cross-sections, and there is no data on Yd elastic scattering cross-sections. The high-luminosity Jefferson Lab experiment E06-103 (g13), in which a real-photon beam was incident on a 40-cm- long liquid deuteron target, offers a unique opportunity to look for hyperon-deuteron elastic scattering signal, Λd being the most promising. In such a dataset, the Λ …

Learning How To Search: Generating Effective Test Cases Through Adaptive Fitness Function Selection, Hussein Khalid Almulla

Theses and Dissertations

Search-based test generation is guided by feedback from one or more fitness functions— scoring functions that judge solution optimality. Choosing informative fitness functions is crucial to meeting the goals of a tester. Unfortunately, many goals—such as forcing the class-under-test to throw exceptions, increasing test suite diversity, and attaining Strong Mutation Coverage—do not have effective fitness function formulations. We propose that meeting such goals requires treating fitness function identification as a secondary optimization step. An adaptive algorithm that can vary the selection of fitness functions could adjust its selection throughout the generation process to maximize goal attainment, based on the current …

Detecting The Intent Of Email Using Embeddings, Deep Learning And Transfer Learning, Zaid Alibadi

Theses and Dissertations

Throughout the years' several strategies and tools were proposed and developed to help the users cope with the problem of email overload, but each of these solutions had its own limitations and, in some cases, contribute to further problems. One major theme that encapsulates many of these solutions is automatically classifying emails into predefined categories (ex: Finance, Sport, Promotion, etc.) then move/tag the incoming email to that particular category. In general, these solutions have two main limitations: 1) they need to adapt to changing user’s behavior. 2) they require handcrafted features engineering which in turn need a lot of time, …

Functional Supramolecular Materials And The Design And Synthesis Of Triple Negative Breast Cancer Pharmaceuticals, Dustin Wayne Goodlett

Theses and Dissertations

Organization of benzophenone in the solid-state facilitates the formation of persistent and regenerable radicals at room temperature upon exposure to light. Upon incident irradiation, the triplet sensitizer rapidly undergoes intersystem crossing to a triplet excited state. Structural investigation of four distinct benzophenone supramolecular assemblies gives insight into the different processes these materials can undertake once in the triplet excited state such as persistent radical formation, phosphorescence, and self-quenching.

Self-assembly of brominated triphenyl amine bis-urea macrocycles forms a host material with unidirectional pores. Separations of xylene constitutional isomers via adsorption within this crystalline host material at ambient temperature are shown to …

Effect Of Oil And Gas Extraction On Disinfection By-Product Formation In Drinking Water, Dallas Graham Abraham

Theses and Dissertations

Certain industrial processes, such as energy extraction and utilization, generate massive amounts of wastewater with various geogenic and synthetic contaminants. Oil and gas wastewaters are characterized by elevated halide levels, particularly geogenic bromide and iodide. Concentrations in produced wastewaters have been reported as high as thousands of mg/L of bromide and tens of mg/L of iodide. Large volumes of these wastewaters are stored, transported, and disposed of, potentially impacting drinking water sources. Because conventional wastewater treatment fails to remove halides, oil and gas wastewater disposal, even after treatment, facilitates the formation of brominated and iodinated disinfection by-products (DBPs) at downstream …

Fate Of Persistent Contaminants And Emerging Algal Toxins In Drinking Water And The Environment, Danielle Christine Westerman

Theses and Dissertations

Population growth and global climate change has resulted in the degradation of pristine water sources, causing issues like saltwater intrusion, persistent harmful algal blooms, and drought from population growth. Future reliance on alternative sources of drinking water to is expected globally, therefore, nontraditional sources of drinking water are becoming increasingly vital sources of potable water around the world. For example, desalination (typically by reverse osmosis), despite its high energy demands and high cost, is being utilized all over the world to meet drinking water demand. Wastewater reuse, the additional treatment of wastewater to produce drinking water, either directly or indirectly, …

A University Forest Fire: Examining The Spread Of The Coronavirus Through College Social Networks Using A Modified Forest Fire Probabilistic Model, Raechel Griffin

Senior Honors Projects

No abstract provided.

Reconstruction Of Historical Surface Mass Balance, 1984–2017 From Greentraacs Multi-Offset Ground-Penetrating Radar, Tate G. Meehan, H.P. Marshall

Geosciences Faculty Publications and Presentations

We present continuous estimates of snow and firn density, layer depth and accumulation from a multi-channel, multi-offset, ground-penetrating radar traverse. Our method uses the electromagnetic velocity, estimated from waveform travel-times measured at common-midpoints between sources and receivers. Previously, common-midpoint radar experiments on ice sheets have been limited to point observations. We completed radar velocity analysis in the upper ∼2 m to estimate the surface and average snow density of the Greenland Ice Sheet. We parameterized the Herron and Langway (1980) firn density and age model using the radar-derived snow density, radar-derived surface mass balance (2015–2017) and reanalysis-derived temperature data. We …

A Hot Mini-Neptune In The Radius Valley Orbiting Solar Analogue Hd 110113, H. P. Osborn, D. J. Armstrong, V. Adibekyan, K. A. Collins, E. Delgado-Mena, S. B. Howell, C. Hellier, G. W. King, J. Lillo-Box, L. D. Nielsen, J. F. Otegi, N. C. Santos, C. Ziegler, D. R. Anderson, C. Briceño, C. Burke, D. Bayliss, D. Barrado, E. M. Bryant, D. J. A. Brown, S. C. C. Barros, F. Bouchy, D. A. Caldwell, D. M. Conti, R. F. Díaz, D. Dragomir, M. Deleuil, O. D. S. Demangeon, C. Dorn, T. Daylan, P. Figueira, R. Helled, S. Hoyer, J. M. Jenkins, Eric L.N. Jensen, D. W. Latham, N. Law, D. R. Louie, A. W. Mann, A. Osborn, D. L. Pollacco, D. R. Rodriguez, B. V. Rackham, G. Ricker, N. J. Scott, S. G. Sousa, S. Seager, K. G. Stassun, J. C. Smith, P. Strøm, S. Udry, J. Villaseñor, R. Vanderspek, R. West, P. J. Wheatley, J. N. Winn

Physics & Astronomy Faculty Works

We report the discovery of HD 110113 b (TESS object of interest-755.01), a transiting mini-Neptune exoplanet on a 2.5-d orbit around the solar-analogue HD 110113 (Teff = 5730 K). Using TESS photometry and High Accuracy Radial velocity Planet Searcher (HARPS) radial velocities gathered by the NCORES program, we find that HD 110113 b has a radius of 2.05 ± 0.12  R⊕ and a mass of 4.55 ± 0.62  M⊕. The resulting density of 2.90+0.75−0.59  g cm−3 is significantly lower than would be expected from a pure-rock world; therefore HD 110113 b must be a mini-Neptune with a significant volatile atmosphere. …

On The Halo-Mass And Radial Scale Dependence Of The Lensing Is Low Effect, J. U. Lange, A. Leauthaud, S. Singh, H. Guo, R. Zhou, Tristan L. Smith, F.-Y. Cyr-Racine

Physics & Astronomy Faculty Works

The canonical Lambda cold dark matter (ΛCDM) cosmological model makes precise predictions for the clustering and lensing properties of galaxies. It has been shown that the lensing amplitude of galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) is lower than expected given their clustering properties. We present new measurements and modelling of galaxies in the BOSS LOWZ sample. We focus on the radial and stellar mass dependence of the lensing amplitude mismatch. We find an amplitude mismatch of around 35 per cent when assuming ΛCDM with Planck Cosmological Microwave Background (CMB) constraints. This offset is independent of halo mass and …

Stitching Dedekind Cuts To Construct The Real Numbers, Michael P. Saclolo

Analysis

No abstract provided.

Institutional Stretching: How Moroccan Ngos Illuminate The Nexus Of Climate, Migration, Gender And Development, Shelby Mertens

Graduate Program in International Studies Theses & Dissertations

The global migration crisis the world has experienced thus far is only the tip of the iceberg. As the earth’s temperature continues to warm and extreme weather conditions worsen, millions of people across the globe will be displaced, and women in particular will face more difficult challenges. What the climate migration literature fails to study is these longer-term impacts beyond sudden onset disasters. Governments and institutions will be forced to respond and adapt to the new reality resulting from the climate crisis. This research provides a case study of Morocco and, by using institutional ethnography, investigates how NGOs working in …

Cybersecurity Legislation And Ransomware Attacks In The United States, 2015-2019, Joseph Skertic

Graduate Program in International Studies Theses & Dissertations

Ransomware has rapidly emerged as a cyber threat which costs the global economy billions of dollars a year. Since 2015, ransomware criminals have increasingly targeted state and local government institutions. These institutions provide critical infrastructure – e.g., emergency services, water, and tax collection – yet they often operate using outdated technology due to limited budgets. This vulnerability makes state and local institutions prime targets for ransomware attacks. Many states have begun to realize the growing threat from ransomware and other cyber threats and have responded through legislative action. When and how is this legislation effective in preventing ransomware attacks? This …

A Study Of The Social, Cultural, And Environmental Influences On Appalachian Agriculture, Morganne May

Senior Theses

Appalachia, despite its rich history and abundant biological and cultural diversity, is commonly associated with a generalized notion of ignorance, resistance to progress, and "backwardness." This study aims to shed light on the socioeconomic, cultural, and environmental influences which have shaped the present food systems of Appalachia through a review of relevant literature. This history provides the necessary context to strategize a region-specific, socioeconomically and environmentally sustainable food system moving forward.

Comparing Dust In Other Galaxies To Dust In Our Galaxy, Fatima Elkhatib

Senior Theses

Interstellar dust in galaxies has a profound effect on the galaxies’ light output and apparent properties as well as on the physical processes connected to star formation. Therefore, to understand the true properties of the galaxies around us, it is important to understand the dust in those galaxies and compare it to the dust in our galaxy. To do this, we study the effects of dust on background quasars by analyzing interstellar reddening and extinction. It has been shown that many quasars look redder and dimmer than the average quasar when observing them from Earth, due to the dust in …

Monarch Science Observer, Volume 9, College Of Sciences, Old Dominion University

College of Sciences Newsletter

Spring 2021 issue of Monarch Science Observer, ODU College of Sciences Newsletter.