Physical Sciences and Mathematics Commons^™

Structure Of Reflectin Protein Probed By Solid-State Nuclear Magnetic Resonance, Tommy Boykin

Electronic Theses and Dissertations

An unusual protein found in squids, termed reflectin, possesses the unique ability for optical reflectivity and proton conductivity. Reflectin has the potential to become optically and electronically tunable, however, the molecular structure of reflectin has yet to be determined. Previous literature has considered using reflectin proteins as diffraction gratings, protonic transistors, and substrates for neural stem cell growth. Applying recombinant protein techniques, we purified the reflectin 4Ax4 protein. We determined the leucine, tryptophan, and threonine amino acids are in an ordered state by solid-state nuclear magnetic resonance (NMR). Knowing these ordered amino acids is possibly the key to understanding reflectin's …

Nanoscale Thermal Transport In Thermally Isolated Nanostructures, Brian G. Green

Electronic Theses and Dissertations

Experiments with nanoscale structures, designed to measure some of their thermal and optical properties, are the subjects of this dissertation. We studied the transport of thermal energy in systems of nanoparticles, and used the method of transient thermoreflectance to monitor those dynamics, and assess whether thermal transport features special to nanoscale systems emerged. This same method was also used to study the thermal transport of a single system of layered membranes. Optical properties were investigated using computational simulations of a nanoparticle system, using the method of finite-difference time-domain simulation.

In nanoparticle studies, there are two features of interest special to …

A Policy Mechanism For Federal Recommendation Of Security Standards For Mobile Devices That Conduct Transactions, Ariel Huckabay

Electronic Theses and Dissertations

The proliferation of mobile devices in the BRIC countries has prompted them to develop policies to manage the security of these devices. In China, mobile devices are a primary tool for payments. As a result, China instituted in 2017 a cyber security policy that applies to mobile devices giving China broad authority to manage cyber threats. The United States has a similar need for a cyber policy. Mobile devices are likely to become a primary payment tool in the United States soon. DHS has also identified a need for more effective security policy in mobile devices for government operations. This …

Community-Based Coastal Restoration: Long Term Impacts On Habitats And People In Volusia County, Rachel Wimmer

Electronic Theses and Dissertations

Coastal habitats provide invaluable economic and ecosystem services. However, coastlines are eroding at increasing rates due to anthropogenic and climate driven changes. Grey and green infrastructure solutions have been proposed to retard the decay of coastlines, with oysters serving as a popular living shoreline. Three community-based stabilizations that implemented living shorelines and engaged local communities in restoration efforts over the past decade in Volusia County were revisited to determine if they were successful and if they produced positive public perceptions of success. Chicken Island, which was restored after waves, boat wakes, tides, and adverse weather altered the natural shoreline, had …

Scheduling Irregular Workloads On Gpus, David Arthur Troendle

Electronic Theses and Dissertations

This doctoral research aims at understanding the nature of the overhead for data irregular GPU workloads, proposing a solution, and examining the consequences of the result. We propose a novel, retry-free GPU workload scheduler for irregular workloads. When used in a Breadth First Search (BFS) algorithm, the proposed simple, monolithic concurrent queue scales to within 10% of ideal scalability on AMD’s Fiji GPU with 14,336 active threads. The dissertation presents an important finding that the retry overhead associated with Compare and Swap (CAS) operations is the principle reason why concurrent queues do not scale well as the number of clients …

Regression Tree Construction For Reinforcement Learning Problems With A General Action Space, Anthony S. Bush Jr

Electronic Theses and Dissertations

Part of the implementation of Reinforcement Learning is constructing a regression of values against states and actions and using that regression model to optimize over actions for a given state. One such common regression technique is that of a decision tree; or in the case of continuous input, a regression tree. In such a case, we fix the states and optimize over actions; however, standard regression trees do not easily optimize over a subset of the input variables\cite{Card1993}. The technique we propose in this thesis is a hybrid of regression trees and kernel regression. First, a regression tree splits over …

Homological Constructions Over A Ring Of Characteristic 2, Michael S. Nelson

Electronic Theses and Dissertations

We study various homological constructions over a ring $R$ of characteristic $2$. We construct chain complexes over a field $K$ of characteristic $2$ using polynomials rings and partial derivatives. We also provide a link from the homology of these chain complexes to the simplicial homology of simplicial complexes. We end by showing how to construct all finitely-generated commutative differential graded $R$-algebras using polynomial rings and partial derivatives.

Wetland Biogeochemical Responses To Predicted Climate Change Scenarios, Angela R. Shaffer

Electronic Theses and Dissertations

Wetlands are one of the world's largest known carbon sinks while comprising only a small amount of the Earth's surface. However, the amount of carbon sequestered by wetlands is shrinking as droughts and human disturbance increases. Carbon in wetlands is stored through the contrast of decomposition and sedimentation of organic matter and absorption of CO₂ from the atmosphere by soil microbes. Understanding how changing hydrological regimes and increased wildfires will affect wetland soil and microbial processes is important in the face of predicted climate change for future wetland conservation practices. Specifically, I seek to understand the response of southeastern …

Investigating Anions And Hydrophobicity Of Deep Eutectic Solvents By Experiment And Computational Simulation, Amos Kwabena Dwamena

Electronic Theses and Dissertations

Deep eutectic solvents are a new generation of ionic liquid-like solvents formed by combining hydrogen bond acceptor with hydrogen bond donor which result in the depression of the melting point of the solvent. Like ionic liquids, anions play a critical role in tuning the polarity, physicochemical properties, and thermodynamic behavior of deep eutectic solvent (DES). Choline chloride is the most widely used quaternary ammonium salt (QAS) in the literature and has remarkable advantages from reduced cost to low toxicity and volatility. Choline bromide and choline iodide are other QAS that have not been used often for DES synthesis and applications, …

Identifying An Optimal Bald Eagle Monitoring Program For Southwest Alaska National Parks, Rebecca Kolstrom

Electronic Theses and Dissertations

The Southwest Alaska Inventory and Monitoring Network includes bald eagle monitoring as part of their Vital Signs Monitoring Plan. Lake Clark National Park and Preserve, Katmai National Park and Preserve, Kenai Fjords National Park, and Wrangell – St. Elias National Park and Preserve monitor bald eagles annually, albeit slightly differently among parks. Since monitoring decisions involve multiple objectives and stakeholders, there was a need for a structured approach to identify an optimal monitoring program. We used a structured decision making process and an iterative, four-round Delphi Process to collect information about long-term bald eagle monitoring from experts. We collected information …

Estimating Soil Organic Carbon In Cultivated Soils Using Soil Test Data, Remote Sensing Imagery From Satellites (Landsat 8 And Plantscope), And Web Soil Survey Data, Muhammed Halil Koparan

Electronic Theses and Dissertations

Soil organic carbon (SOC) is an important soil parameter of cultivated soils that needs to be monitored and mapped regularly to enhance soil health and productivity. SOC levels in cultivated areas is difficult to monitor for farmers and is costly to analyze using traditional methods. The objective of this study was to estimate surface SOC distribution in selected soils of Major Land Resource Areas (MLRA) 102A (Rolling Till Plain, Brookings County, SD) and 103 (Central Iowa and Minnesota Till Prairies, Lac qui Parle County, MN) using soil sample data, Web Soil Survey (WSS) data, and satellite imagery (Landsat 8 and …

Natural Sunlight Photodegradation Of Halogenated Disinfection Byproducts In Water, Ibrahim Abusallout

Electronic Theses and Dissertations

Disinfection byproducts (DBPs) presence in wastewater effluents and receiving waters may impact the quality of drinking water during water reuse practices. Natural solar photolysis is one of the biogeochemical processes that may lead to decreased DBPs concentrations in water. The purpose of this dissertation is to determine the fate of chlorinated, brominated and iodinated DBPs in surface water by natural sunlight photolysis and investigate the use of solar-based advanced oxidation processes (AOPs) for removal of DBPs in water. Total organic halogen (TOX) was used to measure total chlorinated- (TOCl), brominated- (TOBr) and iodinated-DBPs (TOI) in water. The first objective was …

Effect Of Water Velocity And Temperature On Energy Use, Behavior, And Mortality Of Pallid Sturgeon Scaphirhynchus Albus Larvae, Joseph Thomas Mrnak

Electronic Theses and Dissertations

Pallid Sturgeon Scaphirhynchus albus are a federally endangered species endemic to the Missouri River basin. Natural reproduction has been limited for decades and a recruitment bottleneck is hypothesized to occur during the larval stage of development. Understanding factors that affect survival of Pallid Sturgeon larvae is key given their critical status and ongoing recovery efforts. In this study, I evaluated the effects of water velocity and temperature on energy use, behavior, and mortality of endogenously feeding Pallid Sturgeon larvae (< 25 mm TL). In the first experiment, I examined the effect of water velocity (0 – 8.3 cm s⁻¹) on larval growth, energy density, swimming activity, and mortality. Larval growth rate at 16.3 °C was similar across …

Land Cover Changes Within And Around Protected Areas In Côte D’Ivoire From 1986 To 2017: A Case Study Of The Mabi-Yaya-Songan-Tamin Reserved Forests, Olena Boiko

Electronic Theses and Dissertations

Tropical forests mitigate climate change, provide habitat for the most biologically diverse terrestrial communities, and yield ecosystem services that support human wellbeing. These forests are some of the most threatened ecosystems because of the increasing human impact on the environment. Côte d’Ivoire has one of the highest deforestation rates in sub-Saharan Africa, and the expansion of agriculture to produce cash crops, such as cocoa and rubber, is presented as the primary reason for forest loss. These changes are apparent even within the boundaries of the protected areas, which raises concerns about the effectiveness of the protection strategies. This project illustrates …

Effect Of Mineral Ions On The Functional Properties Of Starch Films, Aliza Sigdel

Electronic Theses and Dissertations

Essential minerals are indispensable inorganic micronutrients that modulate vital physiological functions at the molecular level. Their deficiency, though required in small amounts, impairs health significantly. Their supplementation through diet is prudent and carbohydrates standout as favorable choice. Carbohydrates, starches and polysaccharides, exhibit unique chemical structures and functionalities, and interact with mineral ions in several ways. The aim of this research is to investigate the effect of mineral ions on the physicochemical properties, tensile strength and in vitro starch digestion of starch-films. Corn starch and potato starch along with Fe2+, Mn2+, Cu2+ and Zn2+ ions have been chosen as model starch …

Repairable Moment-Resisting Steel Buildings, Heath William Pederson

Electronic Theses and Dissertations

Current seismic design codes ensure life safety for buildings, but structural members may significantly yield or even fail under strong earthquakes. A new design approach is to implement connections that localize the yielding and failure to fuses. A more sophisticated approach is to be able to replace the fuses after the event. The present study was carried out to develop repairable moment-resisting (MR) connections for steel buildings and to investigate their seismic performance through nonlinear finite element analyses (FEA). Two details were proposed using buckling restrained fuses (BRFs) and buckling restrained reinforcement (BRR). Test data was collected from the literature …

In-Silico Design And Synthesis Of Selective Estrogen Receptor Modulators Targeting Ovarian Cancer, John Apraku

Electronic Theses and Dissertations

The established records of the safety of Ormeloxifene along with its favorable bioavailability and ability to inhibit rapid cell proliferation in the endometrium during embryonic implantation has made it one of the best drug candidates for controlling undesirable rapid cell growth such as endometriosis and cancerous tumor conditions. Recent studies have confirmed the effectiveness of Ormeloxifene to suppress and inhibit epithelial-mesenchymal transition process as evidenced by repression of N-cadherin, slug, snail, vimentin, MMPs, β-catenin/TCF-4 transcriptional activity and induce the expression of pGSK3b. Recently conducted studies have revealed the dynamic binding of ormeloxifene with β-catenin, GSK3b, CDK4, and other downstream EGFR. …

Stream Flow Analysis Of The Big Sioux River Just South Of Brookings, South Dakota, Samuel Ruppert

Electronic Theses and Dissertations

Floods are the most common type of natural disaster in the world and one of the most damaging. Changes in climate conditions such as precipitation and temperature are causing changes in stream flow. This means that in order to better understand flooding and possibly develop a system for making flood predictions, stream flow needs to be analyzed more closely. The primary objective of this thesis is to analyze the Big Sioux River just south of Brookings, South Dakota, both annually and seasonally. The United States Geological Survey (USGS) has stream gauges placed in rivers and streams all over the United …

The Economic And Social Values Associated With Small South Dakota Lakes, Aaron Patrick Sundmark

Electronic Theses and Dissertations

The valuation of small fishing lakes is a vital component in understanding the importance of fishing and of recreational resources, in general. Knowing the values associated with such lakes is essential when prioritizing management activities. The overall value of a lake as a resource for human benefit is estimated as the summation of both instrumental and non-instrumental values. Instrumental values consist of economic and utilitarian values, as well as the values that a lake provides from ecosystem services. Non-instrumental values consider what the lake is worth as a good of its own, such as aesthetic, moral, and spiritual values gained …

Assessing Freshwater Mussel (Bivalvia: Unionidae) Assemblages And Effects Of Eutrophication On Pyganodon Grandis In Lakes Of Eastern South Dakota, Katherine M. Wollman

Electronic Theses and Dissertations

Globally, the family Unionidae is the most threatened group of freshwater fauna. South Dakota is well known for its agricultural production, leading to cultural eutrophication from enhanced fertilizers and sediments. This impact can alter species presence, age, growth and mortality. Objectives of this study were to 1) implement the first comprehensive lake survey of freshwater mussels in eastern South Dakota lakes and document distribution, occurrence and relative abundance, 2) evaluate relationships between age, growth and mortality of Pyganodon grandis and lake trophic state. Freshwater mussels were sampled in 2017 from 116 proportionally and randomly selected natural lakes and reservoir basins …

Design, Synthesis And Biological Screening Of Novel Cucs-Inspired Estrone Analogs Towards Treatment Of Pancreatic Adenocarcinoma, Khaled Alseud

Electronic Theses and Dissertations

Pancreatic cancer is currently the fourth most deadly type of cancer globally. It is expected to become the second by 2030, due to its poor prognosis and its resistance to the current standard treatment, Gemcitabine. Moreover, the survival rate after treatment is low compared to other cancer types, which suggests an urgent need for new potent and safe treatment agents. Recently, the triterpenoid, cucurbitacin, has shown promising antiproliferative activity against human pancreatic cancer cells in a dose- and timedependent manner, and decreased pancreatic tumor size in combination with gemcitabine in vivo. However, the use of cucurbitacin in clinical studies has …

Greater Sage-Grouse Survival, Breeding Ecology, Resource Selection, And West Nile Virus Prevalence On The Eastern Fringe Of Their Range, Lindsey Anne Parsons

Electronic Theses and Dissertations

The greater sage-grouse (Centrocercus urophasianus) is a sagebrush (Artemisia spp.) obligate species that has experienced population declines over the past several decades. Sage-grouse are a species of conservation concern throughout the Intermountain West and are considered a species of greatest conservation need in South Dakota. Numerous studies have documented drivers of demographic performance at the core of their distribution; however, relatively few studies have examined sage-grouse inhabiting the eastern extent of their range, in South Dakota. We sought to examine sage-grouse space use in multiple seasons, estimate survival, and determine factors affecting nest success in South Dakota …

Rigid Equilibriums Of A Rotating String, Teddrick Schaffer

Electronic Theses and Dissertations

This paper describes some possible equilibrium configurations of a string rotating in a certain class of force fields, which have properties motivated by the inverse square gravitational force. Specifically it is shown that for a given number n, there exists a sufficient rotational rate such that any equilibrium configuration with no more than n zeros is guaranteed to exist for any force field in the class considered.

Development Of A Data-Driven Patient Engagement Score Using Finite Mixture Models, Eric Bae

Electronic Theses and Dissertations

Patient activation measure (PAM) is widely adopted by health care providers to access individual's knowledge, skill, and confidence for managing one's health and healthcare. Patient activation measure (PAM), licensed by Insignia Health, is widely adopted by health care providers to access individual's knowledge, skill, and confidence for managing one's health and healthcare. Multiple studies corroborate the effectiveness of activation measure in predicting most health behaviors, including preventive behaviors, healthy behaviors, self-management behaviors, and health information seeking. However, PAM is heavily dependent on subjective patient-reported data, which are often incomplete. The purpose of this study is to develop an objective statistical …

A Dynamic Fault Tolerance Model For Microservices Architecture, Hajar Hameed Addeen

Electronic Theses and Dissertations

Microservices architecture is popular for its distributive system styles due to the independent character of each of the services in the architecture. Microservices are built to be single and each service has its running process and interconnecting with a lightweight mechanism that called application programming interface (API). The interaction through microservices needs to communicate internally. Microservices are a service that is likely to become unreachable to its consumers because, in any distributed setup, communication will fail on occasions due to the number of messages passing between services. Failures can occur when the networks are unreliable, and thus the connections can …

Finite Mixture Of Regression Models For Complex Survey Data, Abdelbaset Abdalla

Electronic Theses and Dissertations

Over time, survey data has become an essential source of information for modern society. However, to be effective, the structures of survey data require sampling designs that are more complex than simple random sampling. The complex sampling data collected from enormous national surveys via these complex designs ideally include sample weights that allow analysis to take account of complicated population structures. When the target of inference is the parameters of a regression model, it is crucial to know whether these weights should be incorporated into the sampling weight when fitting the model to the survey data. The finite mixture models …

The Tortoise (Wildfire) And The Hare (Heavy Winter Grazing) For Promoting Heterogeneity And Improving Ecosystem Services, Lucas W. Zilverberg

Electronic Theses and Dissertations

The Northern Great Plains (NGP) mixed-grass prairie developed under fire, grazing, and periodic droughts, which created a heterogeneous landscape. Since European settlement, heterogeneous landscapes have declined due to fire suppression and the maximization of livestock production, leading to the need for an alternative management practice. Our overall project objective was to determine if heavy winter grazing could be used as an alternative to patch-burn grazing for promoting heterogeneity and improving ecosystem services in the NGP. Fire has been used very effectively in patch-burn grazing management to create heterogeneity in pastures in some areas, however burning is not readily adopted in …

Variability Of E. Coli In Streambed Sediments And Its Implication For Water Quality, Sadia Salam

Electronic Theses and Dissertations

Fecal indicator bacteria (FIB), including E. coli, are the number one cause of water quality impairments in the United States according to the USEPA. FIB are used as a predictor to identify the possible presence of pathogens in waterbodies. E. coli is a useful indicator of gastrointestinal (GI) related illnesses from contact with fresh water. While surface water is routinely monitored for water quality, streambed sediments are rarely considered as a source of FIB to the overlying water column. This study focuses on understanding the variation of E. coli concentrations in streambed sediments and the potential impact of sediment sources …

Winter Snow Depth In Arctic Alaska Results In Complex Changes In Caribou Forage Quality, Jessica C. Richert

Electronic Theses and Dissertations

Caribou (Rangifer tarandus) rely on the short growing season for much of their annual nutrition, making them susceptible to even small changes in forage quantity and quality. Body condition in the summer and fall is linked to winter survival rates and fecundity in cows, critical factors in the robustness of caribou populations. Due to a warmer, wetter climate, snowfall is predicted to increase over Alaska’s North Slope in the next several decades. Deeper snow results in higher soil temperatures, allowing microbial mineralization of nitrogen to continue throughout the winter and increasing the availability of nitrogen for plants in spring and …

How Are Interannual Variations Of Land Surface Phenology In The Highland Pastures Of Kyrgyzstan Modulated By Terrain, Snow Cover Seasonality, And Climate Oscillations? An Investigation Using Multi-Source Remote Sensing Data, Monika Anna Tomaszewska

Electronic Theses and Dissertations

In the semiarid, continental climates of montane Central Asia, with its constant moisture deficit and low relative humidity, agropastoralism constitutes the foundation of the rural economy. In Kyrgyzstan, an impoverished, landlocked republic in Central Asia, herders of the highlands practice vertical transhumance—the annual movement of livestock to higher elevation pastures to take advantage of seasonally available forage resources. Dependency on pasture resource availability during the short mountain growing season makes herds and herders susceptible to changing weather and climate patterns. This dissertation focuses on using remote sensing observations over the highland pastures in Kyrgyzstan to address five interrelated topics: (i) …