Physical Sciences and Mathematics Commons^™

Perchlorate Variations Over 300 Years: Influence Of Human Activities, Volcanic Eruptions And Bolide Events, Kari Peterson

Electronic Theses and Dissertations

Perchlorate, which derives from both anthropogenic and natural sources in the current environment, constitutes a significant health risk to humans because it competitively inhibits iodine uptake by the thyroid gland. Thus, there has been considerable interest in reducing the human exposure to environmental perchlorate by limiting the release of perchlorate from anthropogenic sources. However, a lack of understanding of the relative contributions from anthropogenic and natural sources has prevented widespread regulation. A 300-year ice core perchlorate record from Summit Station, Greenland (1700-2007 C.E.) that extends beyond the onset of the Industrial Revolution (1850 C.E.) is used to assess the anthropogenic …

Similarity Measurement Of Breast Cancer Mammographic Images Using Combination Of Mesh Distance Fourier Transform And Global Features, Ravi Kasaudhan

Electronic Theses and Dissertations

Similarity measurement in breast cancer is an important aspect of determining the vulnerability of detected masses based on the previous cases. It is used to retrieve the most similar image for a given mammographic query image from a collection of previously archived images. By analyzing these results, doctors and radiologists can more accurately diagnose early-stage breast cancer and determine the best treatment. The direct result is better prognoses for breast cancer patients. Similarity measurement in images has always been a challenging task in the field of pattern recognition. A widely-adopted strategy in Content-Based Image Retrieval (CBIR) is comparison of local …

Land Cover Land Use Change And Soil Organic Carbon Under Climate Variability In The Semi-Arid West African Sahel (1960-2050), Amadou M. Dieye

Electronic Theses and Dissertations

Land Cover Land Use (LCLU) change affects land surface processes recognized to influence climate change at local, national and global levels. Soil organic carbon is a key component for the functioning of agro-ecosystems and has a direct effect on the physical, chemical and biological characteristics of the soil. The capacity to model and project LCLU change is of considerable interest for mitigation and adaptation measures in response to climate change. A combination of remote sensing analyses, qualitative social survey techniques, and biogeochemical modeling was used to study the relationships between climate change, LCLU change and soil organic carbon in the …

Breast Cancer Classification Of Mammographic Masses Using Circularity Max Metric, A New Method, Tae Keun Heo

Electronic Theses and Dissertations

Breast cancer classification can be divided into two categories. The first category is a benign tumor, and the other is a malignant tumor. The main purpose of breast cancer classification is to classify abnormalities into benign or malignant classes and thus help physicians with further analysis by minimizing potential errors that can be made by fatigued or inexperienced physicians. This paper proposes a new shape metric based on the area ratio of a circle to classify mammographic images into benign and malignant class. Support Vector Machine is used as a machine learning tool for training and classification purposes. The improved …

Current Status Of Falcon Populations In Saudi Arabia, Albara M. Binothman

Electronic Theses and Dissertations

Falcons (Falco spp.) are widely used for falconry in the countries of the Middle East. During the 2015 breeding season, we surveyed historic and active nest sites of Barbary (Falco pelegrinoides pelegrinoides) and Lanner (F. biarmicus) Falcons in Saudi Arabia. Field and questionnaire surveys were conducted and personal contact with falconers was made to document the current distribution and price changes for Lanner Falcons, Barbary Falcons, Saker Falcons (F. cherrug), Peregrine Falcons (F. peregrinus), Gyrfalcons (F. rusticolus), and Hybrid Falcons in Saudi Arabia. We categorized our survey into three geographic groups; southwest (A), northwest (B), and central (C) regions of …

Ecology Of Largemouth Bass In An Aging Reservoir: Implications For Creating A Trophy Largemouth Bass Fishery, Jason Breeggemann

Electronic Theses and Dissertations

There are an estimated 3-9 million small reservoirs and nearly 1,000 large reservoirs in the United States. Most of these reservoirs were built several decades ago and are experiencing symptoms of reservoir aging, including loss of habitat, sedimentation, and decreased fishery production. Furthermore, over the last several decades, there has been an increasing interest among anglers for high quality, trophy fisheries. However, little is known about exactly how the reservoir aging process affects the ecology and especially growth potential of Largemouth Bass, particularly under potential climate change scenarios. Grand Lake in TX is a 45ha ageing reservoir that was built …

Simulating The Impacts Of Land-Use Land-Cover Changes On Cropland Carbon Fluxes In The Midwest Of The United States, Zhengpeng Li

Electronic Theses and Dissertations

Understanding the major drivers of the cropland carbon fluxes is important for carbon management and greenhouse gas mitigation in agriculture. Past studies found that agricultural land-use and land-cover (LULC) changes, such as changes in cropland production technologies, tillage practices, and planted crop species, could have large impacts on carbon fluxes. However, the impacts remain highly uncertain at regional to global scales. Satellite remote sensing is commonly used to create products with geospatial information on LULC changes. This geospatial information can be integrated into biogeochemical models to simulate the spatial and temporal patterns of carbon fluxes. We used the General Ensemble …

Environmentally Benign Extraction Processes In Analytical Separation Of Essential Oils, John Kiratu

Electronic Theses and Dissertations

Supercritical fluid extraction (SFE) technology has been well received as an environmentally friendly processing technique. Over the last two decades, its use in many processing industries has tremendously advanced. This is as a result of pressure from regulating bodies aimed at reducing the wide-scale use of organic solvents due to negative environmental impacts. Supercritical carbon dioxide (SC-CO2) is considered to be environmentally benign and has been used in the development of a wide-range of alternative processes in various industries to totally or partially eliminate the use of organic solvents. Conventional processes for essential oil extraction involve steam distillation and organic …

Functional Effects Of Calcium Regulation Of Thin Filaments At Single Particle Resolution, Christopher Solis-Ocampo

Electronic Theses and Dissertations

Heart disease is the leading cause of death in the United States. Understanding heart function at the molecular level is critical for developing of more effective treatments. In the cardiac muscle, the thin filament is composed by troponin (Tn), tropomyosin (Tm), and F-actin. It provides Ca2+-dependent regulation of contraction by modulating myosin attachment and force generation in a cooperative scheme. However, this mechanism remains unclear. To understand thin filament activation, we studied the binding and functional properties of Tn and Tm to F-actin at single particle resolution by employing fluorescence image colocalization, in vitro motility assays, and Förster resonance energy …

Product Authentication Using Hash Chains And Printed Qr Codes, Harshith R. Keni

Electronic Theses and Dissertations

This thesis explores the usage of simple printed tags for authenticating products. Printed tags are a cheap alternative to RFID and other tag based systems and do not require specialized equipment. Due to the simplistic nature of such printed codes, many security issues like tag impersonation, server impersonation, reader impersonation, replay attacks and denial of service present in RFID based solutions need to be handled differently. An algorithm that utilizes hash chains to secure such simple tags while still keeping cost low is discussed. The security characteristics of this scheme as well as other product authentication schemes that use RFID …

Financial Investment Management For Forest Sustainability, Zarina Ismailova

Electronic Theses and Dissertations

This is paper is discussion about main problems of forest management, whether financial investment has a substantial impact on the long term perspective of forest landscape restoration and, more specifically, what strategy and what financial options are available to make the forest projects more sustainable. A few relevant questions to ask are: who are the main actors in the implementation of FLR projects; which steps have to be taken; and, which financial options would more suitable and would be feasible to implement. There are three main parts of this research to be investigated:

1. forest issues along with their respective solutions, …

Mechanistic Studies Of The Structure-Photostability Relationship Of Organic Conjugated Polymers, Logan Paul Sanow

Electronic Theses and Dissertations

Organic Conjugated polymers (CPs) are a subject of intense research for their application in organic photovoltaics (OPVs), organic light emitting diodes (OLEDs), solid-state dye lasing, biological imaging and sensing, chemical sensing and remote sensing. CPs are key materials in the quest for more sustainable forms of renewable energy, making electronics more versatile and light weight, and increasing the functionality of everyday materials. For these applications and others that use CPs as the photoactive material, one of their main drawbacks is their susceptibility to photodegradation. Photodegradation occurs when the material is exposed to light leading to irreversible changes in the materials, …

A Physiological Assessment Of Wetland Habitats For Spring-Migrating Ducks In The Agricultural Landscapes Of The Southern Prairie Pothole Region, Adam K. Janke

Electronic Theses and Dissertations

The conversion of grassland and wetland ecosystems in the Prairie Pothole Region (PPR) has been a pervasive challenge for conservationists dating back to the early 1900s. The legacy of ever-increasing agricultural intensity in the southern portions of the PPR, including eastern South Dakota, has left many wetland ecosystems in a matrix of intensive agricultural production. With little surrounding nesting cover, these wetlands are thought to have limited potential for waterfowl reproduction but may still play an important role facilitating migration of waterfowl en route to northern breeding areas during spring. My research sought to understand the contributions of wetlands in …

Changes In Wetland Conditions And Wetland Plant Communities In The Prairie Pothole Region After 50 Years, Ryann Cressey

Electronic Theses and Dissertations

Wetlands in Stutsman County, North Dakota were revisited after 50 years to assess changes in wetland conditions and plant communities within wetland zones in the Prairie Pothole Region. In 1961-1966, Robert E. Stewart and Harold A. Kantrud conducted a study to investigate the relationship of wetland plant communities to variations of water permanence and chemistry on three study areas: Crystal Springs, Cottonwood, and Mt. Moriah. Within in this region, a severe drought occurred in 1988- 1992 followed by the longest deluge starting in 1993 with wetlands still impacted today. In 2013 and 2014, I revisited 80 of the original wetlands …

Raptors In Temperate Grasslands: Ecology Of Ferruginous Hawk, Golden Eagle, And Northern Harrier In The Northern Great Plains, Shubham Datta

Electronic Theses and Dissertations

Ferruginous hawks (Buteo regalis) are a grassland and shrubland obligate nesting raptor and prefer lightly grazed pasture or idle areas for nesting. Their population reportedly declines in number if more than 30% of an area is cultivated and they rarely nest in areas dominated by croplands. Golden eagles (Aquila chrysaetos) are long-lived raptors with high nest-site fidelity and relatively low reproductive success. Population trends of golden eagles in western United States are unclear although long-term monitoring of populations shows declines in occupancy and breeding performance. Northern harriers (Circus cyaneus) prefer relatively open grasslands and …

Bioinformatics Investigation On The Role Of Obox Gene Family In Preimplantation Embryo Development, Wei Wang

Electronic Theses and Dissertations

Preimplantation embryo development (PED) refers to the period from fertilization to implantation in mammals. This complex process is critical for successful implantation and pregnancy. Although studies on PED have been conducted, using mainly the mouse as a model organism, the gene regulatory mechanisms are still not well understood. The next-generation sequencing technologies enable researchers to obtain the genome-wide expression profiling with single-cell resolution, which are powerful tools to study early embryogenesis. We used the single-cell RNA sequencing datasets that are available in the public domain and conducted bioinformatics analysis of expression profiling from zygote to blastocyst. Through hierarchical clustering of …

Effect Of Oil And Natural Gas Development On Survival And Health Of White-Tailed Deer In The Western Dakotas, Katherine L. Moratz

Electronic Theses and Dissertations

Oil and gas development in North Dakota has resulted in the need for information regarding how increased activity has affected white-tailed deer (Odocoileus virginianus) populations. We evaluated white-tailed deer ecology in response to energy development and hypothesized that oil and gas development would negatively affect adult and neonate white-tailed deer due to increased vehicle traffic and human-related effects. We captured and radio-collared adult female and neonate white-tailed deer across three study areas: Dunn County, North Dakota, an area influenced by energy development, and Grant County, North Dakota, and Perkins County, South Dakota, areas not impacted by energy development at this …

Identifying Data Centers From Satellite Imagery, Adam Buskirk

Electronic Theses and Dissertations

We develop two different descriptors which can be utilized to describe satellite imagery. The first, the differential-magnitude and radius descriptor, describes a scene by computing the directional gradient of the scene with respect to a vector field whose solutions are circles around a pixel to be described, and then counts pixels in a descriptor matrix according to the magnitude of this gradient and the distance at which this magnitude occurs. The second, the radial Fourier descriptor, extracts from the scene a sequence of annuloid sectors, and uses this to approximate the behavior of the image on a circle around the …

Ice Concentration Linked With Extractive Stirrer (Icecles), Nujud Omar Maslamani

Electronic Theses and Dissertations

Clean water is very important for human health. Therefore, drinking water contamination is a significant research concern, especially with the increasing global population. Some contaminants, such as pesticides, can cause health effects even at low levels. Therefore, trace and ultratrace analysis of contaminants in drinking water is essential. Ultratrace analysis typically requires highly effective sample preparation methods and/or highly sensitive instruments. There are currently advanced sample preparations techniques available to analytical chemists that may allow trace analysis of certain analytes. These include liquid-liquid extraction (LLE), solid phase extraction (SPE), solid phase micro extraction (SPME), and stir bar sorpitive extraction (SBSE). …

Use Of Extraction Technologies In Food Safety Studies, Changling Qiu

Electronic Theses and Dissertations

Food safety has become a top concern in our society. The public in general is increasingly concerned about the safety of the food products they consume every day as more and more food contamination incidents and widespread recalls arise. It is necessary to trace any presence and/or the concentration levels of contaminants, pesticides, herbicides, or other harmful substances in food samples. Sample preparation is a crucial step in a food analytical method, as it takes up most of the total analysis time, contributing highly to the total cost of analysis and greatly influencing the results of the analysis. Traditional extraction …