Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Life Sciences (16)
- Environmental Sciences (9)
- Plant Sciences (7)
- Agronomy and Crop Sciences (6)
- Earth Sciences (6)
-
- Soil Science (5)
- Water Resource Management (5)
- Engineering (3)
- Fresh Water Studies (3)
- Oceanography and Atmospheric Sciences and Meteorology (3)
- Agricultural Science (2)
- Agriculture (2)
- Animal Sciences (2)
- Applied Mathematics (2)
- Biochemistry, Biophysics, and Structural Biology (2)
- Bioinformatics (2)
- Biophysics (2)
- Chemistry (2)
- Natural Resources Management and Policy (2)
- Physics (2)
- Poultry or Avian Science (2)
- Agricultural Education (1)
- Animal Studies (1)
- Astrophysics and Astronomy (1)
- Biomedical (1)
- Bioresource and Agricultural Engineering (1)
- Biostatistics (1)
- Biotechnology (1)
- Civil and Environmental Engineering (1)
- Institution
Articles 1 - 23 of 23
Full-Text Articles in Physical Sciences and Mathematics
Assessing Trichloromethane Formation And Control In Algal-Stimulated Waters Amended With Nitrogen And Phosphorus, Clinton Mash
Assessing Trichloromethane Formation And Control In Algal-Stimulated Waters Amended With Nitrogen And Phosphorus, Clinton Mash
Graduate Theses and Dissertations
Nitrogen (N) and phosphorus (P) enrichments can stimulate algal growth in drinking water sources, which can cause increased production of disinfection byproduct (DBP) precursors. However, the effect of systematic N and P enrichments on DBP formation and control has not been adequately studied. In this work, we enriched samples from a drinking water source - sampled on April 5, May 30, and August 19, 2013 - with N and P to stimulate algal growth at N:P ratios covering almost five orders of magnitude (0.2-4,429). To simulate DBP-precursor removal processes at drinking water treatment plants (DWTPs), the samples were treated with …
Long-Term Residue And Water Management Effects On Soil Respiration And Soil Aggregate Stability In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Sharon Faye Smith
Long-Term Residue And Water Management Effects On Soil Respiration And Soil Aggregate Stability In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Sharon Faye Smith
Graduate Theses and Dissertations
Sustainability in agriculture is paramount to assuring continued production from our most naturally fertile soils. Storing carbon (C) in soil as organic matter through sustainable agricultural management practices can both remove atmospheric C and improve soil quality. The objective of this study was to evaluate the long-term effects of water management (irrigation and dryland), residue management [burn and no-burn, conventional (CT) and no-tillage (NT)] and residue/fertility level (high and low) on soil respiration and aggregate stability in a wheat- (Triticum aestivum L.) soybean [Glycine max (L.) Merr.], double-crop system in a silt-loam soil (Aquic Fraglossudalf) in the Mississippi River Delta …
Bacterially-Mediated Formation Of Rock Coatings In Kärkevagge, Swedish Lapland: A Mineralogical And Micro-Environmental Analog For Mars, Cassandra L. Marnocha
Bacterially-Mediated Formation Of Rock Coatings In Kärkevagge, Swedish Lapland: A Mineralogical And Micro-Environmental Analog For Mars, Cassandra L. Marnocha
Graduate Theses and Dissertations
The search for past or present life on Mars is, for now, limited to surface environments. An often neglected surface environment that could have served as an abode for life and could presently preserve evidence of that life is that of rock coatings. Rock coatings are mineral accretions on rock surfaces. On Earth, they are widespread and occur with considerable chemical diversity. There is growing evidence for a biotic role in their formation on Earth, particularly with respect to rock varnish. As a result, rock varnish has become a target of astrobiological interest on Mars, where varnish-like coatings have been …
Reservoir Management Techniques To Enhance Biological Productivity And Protect Water Quality, Ben Alan Thompson
Reservoir Management Techniques To Enhance Biological Productivity And Protect Water Quality, Ben Alan Thompson
Graduate Theses and Dissertations
Three reservoirs of similar size, watershed land use, and qualitative characteristics in northwest Arkansas, USA were selected to compare the effects of chemical fertilization and pulsed artificial-upwelling on whole-lake productivity, specifically primary production and phytoplankton biomass. Numerous water quality parameters were quantified over a two year period (2011-13) with the goal of understanding how each management technique would stimulate productivity. This experiment was the first step towards a larger goal to ultimately enhance sport fish production. The first year of monitoring occurred in 2011 and served as a control year for the three lakes. Treatments were initiated in two of …
Quantitative Trait Loci Associated With Waterlogging Tolerance In A Soft Red Winter Wheat Mapping Population, Diana Carolina Ballesteros Benavides
Quantitative Trait Loci Associated With Waterlogging Tolerance In A Soft Red Winter Wheat Mapping Population, Diana Carolina Ballesteros Benavides
Graduate Theses and Dissertations
Waterlogging is caused when water stays superficially in the soil for an extended period of time, creating an anaerobic environment which decreases plant growth and grain yield at maturity. Despite the impact of waterlogging on wheat production both globally and in the southeastern U.S., very little is known about the genetic control of waterlogging tolerance in wheat. The objective of this study was to determine the amount of genetic variation for vegetative stage waterlogging tolerance present within a wheat recombinant inbred line (RIL) population and to identify quantitative trait loci (QTL) associated with tolerance and productivity. Experiments were carried out …
Biological Compatibility And Cytotoxicity Studies Of Hepa-1c1c7, Hepg2, And Mcf-7 Cancer Cell Lines Upon Exposure To Silver, Palladium, And Gold Nanoparticles, M. Esther Salinas
Biological Compatibility And Cytotoxicity Studies Of Hepa-1c1c7, Hepg2, And Mcf-7 Cancer Cell Lines Upon Exposure To Silver, Palladium, And Gold Nanoparticles, M. Esther Salinas
Theses and Dissertations - UTB/UTPA
The field of nanomedicine has recently explored potential applications for cancer treatment ranging from drug delivery methods to cancer imaging techniques. Due to potential risks of nanomaterials affecting non-cancerous cells in the body, in vitro toxicity studies are being conducted. The nanoparticles (NPs) were synthesized from potassium tetrachloroaurate (III) hydrate, potassium tetrabromoaurate (III) dihydrate, potassium tetrachloropalladate (II), and silver nitrate. NPs were synthesized using the Turkevich method or through the sodium borohydride reduction. Particles synthesized using sodium borohydride were stabilized with cetyltrimethylammonium bromide (CTAB). The NPs under investigation were used to treat three cancer cell lines. The treated cells were …
Estimation Of Variation For High-Throughput Molecular Biological Experiments With Small Sample Size, Danni Yu
Estimation Of Variation For High-Throughput Molecular Biological Experiments With Small Sample Size, Danni Yu
Open Access Dissertations
Motivation: In the quantification of molecular components, a large variation can affect and even potentially mislead the biological conclusions. Meanwhile, the high-throughput experiments often involve a small number of samples due to the limitation of cost and time. In such cases, the stochastic information may dominate the outcome of an experiment because there may not be enough samples to present the true biological information. It is challenging to distinguish the changes in phenotype from the stochastic variation.
Methods: Since the biological molecules have been quantified with different technologies, different statistical methods are required. Focusing on three types of important high-throughput …
Nitrogen And Potassium Dynamics Of Selected Indiana Soils, Chun Zhao
Nitrogen And Potassium Dynamics Of Selected Indiana Soils, Chun Zhao
Open Access Dissertations
Nitrogen (N) is the most limiting essential nutrient for crop growth. Numerous studies have been performed to improve N fertilizer recommendations. Accurate prediction of soil N supply has been found to be one of the most important factors that determine optimum fertilizer N rates. Seven soils collected from various locations across Indiana at four different depths were tested for N mineralization potential. Results showed that laboratory mineralizable N in the top layer (0-15 cm) of the seven soils ranged from 50 to 68 mg N kg-1 soil. In addition, more than 50% of the total mineralizable N was contributed from …
Observation-Based Algorithm Development For Subsurface Hydrology In Northern Temperate Wetlands, Chun-Mei Chiu
Observation-Based Algorithm Development For Subsurface Hydrology In Northern Temperate Wetlands, Chun-Mei Chiu
Open Access Dissertations
This study investigates wetland subsurface hydrology, as well as biogeochemistry - which is strongly influenced by water and temperature dynamics - as these interactions are expected to be highly significant, yet remain poorly represented in current ecosystem and climate models.
Northern wetlands have received widespread public attention due to steadily increasing summer mean global temperatures, extreme precipitation events and higher rates of natural greenhouse gas emissions, as well as the significant impacts on them due to human activities. The goal of my graduate research has been to improve quantification of the role of subsurface hydrology in northern wetlands by using …
Evaluation Of Water Sanitation Options For Poultry Production, Pramir Maharjan
Evaluation Of Water Sanitation Options For Poultry Production, Pramir Maharjan
Graduate Theses and Dissertations
An evaluation of poultry farm water supplies was conducted to determine the value and impact of water system sanitation practices in commercial broiler houses on microbial levels. Water line cleaning between flocks using concentrated disinfectant solution before placing chicks reduced biofilms retained in the lines to a safe level. Occasional microbial surges were noticed during different points of flock grow-out period even when daily water sanitation was present indicating water is highly susceptible to microbial contamination. However, the daily water sanitation practice controlled the occasional microbial surges in water from sustaining and kept drinking water to a microbiologically acceptable level. …
The Use Of Non-Traditional Technologies To Improve The Efficiency And Sustainability Of Modern Poultry Production, Christopher Pixley
The Use Of Non-Traditional Technologies To Improve The Efficiency And Sustainability Of Modern Poultry Production, Christopher Pixley
Graduate Theses and Dissertations
Historically, major driving factors for the animal agriculture industry have been efficiency and profitability. As demand for efficient food production has increased, the industry has focused research efforts on ways to improve the rearing process. Current market demands are requiring the industry to abandon some of the traditional tools it has used to maximize productivity. However, developing alternative technologies are available which may fill the void. Unfortunately, these alternatives are less well-described and the beneficial impacts they can have are not fully understood. As the animal agriculture industry matures it is becoming evident that consumers will continue to demand methods …
Dynamical Behaviors Of Gonorrhea Strain Competition Model, Marisabel Rodriguez
Dynamical Behaviors Of Gonorrhea Strain Competition Model, Marisabel Rodriguez
Theses and Dissertations - UTB/UTPA
In the past decades, Gonorrhea, a sexually transmitted bacterial infection caused by Neisseria gonorrhoeae, has become resistant to a wider range of antibiotics. We apply a phenomenological model that takes into account essential ideas such as the effects of different treatment levels, the transformation and conjugation rates of bacteria, and the response of the immune system. Qualitative analysis provides a more integral view of how model parameters affect the emergence of within-host resistance.
A Mathematical Model And Numerical Method For Thermoelectric Dna Sequencing, Liwei Shi
A Mathematical Model And Numerical Method For Thermoelectric Dna Sequencing, Liwei Shi
Doctoral Dissertations
DNA sequencing is the process of determining the precise order of nucleotide bases, adenine, guanine, cytosine, and thymine within a DNA molecule. It includes any method or technology that is used to determine the order of the four bases in a strand of DNA. The advent of rapid DNA sequencing methods has greatly accelerated biological and medical research and discovery. Thermoelectric DNA sequencing is a novel method to sequence DNA by measuring the heat that is released when DNA polymerase inserts a deoxyribonucleoside triphosphate into a growing DNA strand. The thermoelectric device for this project is composed of four parts: …
Biodiesel Transesterification Byproducts As Soil Amendments, Solomon Parker
Biodiesel Transesterification Byproducts As Soil Amendments, Solomon Parker
Graduate Theses and Dissertations
For every ten kilograms of biodiesel that is produced from the transesterification of vegetable oil, approximately 1 kg of glycerol is produced as a byproduct. Also known as glycerin, it is a chemical used in many products including cosmetics, foods, and desiccants. However, the crude glycerol created during biodiesel production is tainted with potassium hydroxide and methanol making it unsuitable for commercial use without costly refinement. With increase in production of biodiesel driven by rising fuel prices, the market has become glutted with glycerol and it is on the threshold of becoming a waste product. Common methods for disposing glycerol …
Interactions Between Ions And Lysenin Nanochannels And Their Potential Applications As Biosensors, Radwan Awwad Al Faouri
Interactions Between Ions And Lysenin Nanochannels And Their Potential Applications As Biosensors, Radwan Awwad Al Faouri
Graduate Theses and Dissertations
Lysenin is classified as a pore-forming toxin protein that is isolated from the earthworm Eisenia fetida and consists of 297 amino acids [1]. Lysenin inserts large conducting pores (3.0-4.7 nm in diameter) into artificial membranes (BLM) which include sphingomyelin. These pores (channels) are open and oriented upon insertion into the bilayer lipid membrane. Lysenin channels gate at positive voltages (voltage-induced gating), but not at negative voltages. Lysenin pores also exhibit activity modulation in response to changes in ionic strength and pH, indicating that electrostatic interaction is responsible for Lysenin conductance activities. In this line of inquiries, and by modulating Lysenin …
A Cradle To Farm Gate Life Cycle Analysis Of Water Use In U.S. Pork Production, Eric Boles
A Cradle To Farm Gate Life Cycle Analysis Of Water Use In U.S. Pork Production, Eric Boles
Graduate Theses and Dissertations
The intent of this study was to analyze water use across a range of regions, scales and practices of the U.S. pork industry. A Life Cycle Assessment of water use within the pork supply chain was performed. Cumulative water use was the environmental impact category used in the LCA to evaluate the impacts of pork production processes throughout the pork supply chain. The functional unit for the analysis was the volume of water required to produce one kilogram of swine (live weight) at the farm gate.
A comprehensive literature review was used to design and propagate algorithms for the National …
The Geometry And Sensitivity Of Ion-Beam Sculpted Nanopores For Single Molecule Dna Analysis, Ryan Connor Rollings
The Geometry And Sensitivity Of Ion-Beam Sculpted Nanopores For Single Molecule Dna Analysis, Ryan Connor Rollings
Graduate Theses and Dissertations
In this dissertation, the relationship between the geometry of ion-beam sculpted solid-state nanopores and their ability to analyze single DNA molecules using resistive pulse sensing is investigated. To accomplish this, the three dimensional shape of the nanopore is determined using energy filtered and tomographic transmission electron microscopy. It is shown that this information enables the prediction of the ionic current passing through a voltage biased nanopore and improves the prediction of the magnitude of current drop signals when the nanopore interacts with single DNA molecules. The dimensional stability of nanopores in solution is monitored using this information and is improved …
Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays
Graduate Theses and Dissertations
In March 2006, four groundcover management systems (GMS) and two nutrient sources (NS) were implemented for their ability to alter the soil physical condition of a newly established, organically managed apple (Malus x domestica Borkh.) orchard. Annual applications of municipal green compost (GC), shredded office paper (SP), wood chips (WC), and mow-blow (MB) grass mulch were utilized as GMS, and NS supplied to trees were from composted poultry litter (PL), a commercial organic fertilizer (CF), or an untreated control (NF) in a 4x3 factorial study. An established, conventionally-managed orchard was located adjacent to the organic research orchard on the same …
Modeling Greenhouse Gas Emissions And Net Return Implications For Cow-Calf Producers In The Ozark Highlands, Stephen Aaron Smith
Modeling Greenhouse Gas Emissions And Net Return Implications For Cow-Calf Producers In The Ozark Highlands, Stephen Aaron Smith
Graduate Theses and Dissertations
Cow-calf producers in the Ozark Highlands region are under continuous pressure to improve economic efficiency. Additionally, estimating greenhouse gas (GHG) emissions from cow-calf and forage production processes may become increasingly important as policy makers seek to mitigate or reduce agriculture's role in climate change. As such, this analysis had three objectives. Objective 1: Provide a model that could be used by cow-calf producers, extension agents, and researchers to evaluate GHG and net return (NR) repercussions when modifying site characteristics, production methods, and inputs. Objective 2: Develop a user guide such that the methodology for estimating cow-calf GHG emissions and NR …
Evolution Of Complex Features In Digital Organisms, Javier A. Magana
Evolution Of Complex Features In Digital Organisms, Javier A. Magana
Theses and Dissertations - UTB/UTPA
This thesis examines how complex features evolve in digital organisms, and how capabilities that evolved earlier provide a scaffold for evolving new features. I wanted to see how the organisms used previous adaptations to succeed in new environments, and how significant are these previous adaptations. The system used is the Avida platform, which is software that implements Darwinian evolution on self-replicating digital organisms. First, the system is seeded with ancestors that can only replicate, which gave a baseline for the quality of the task at the end of evolution. Second, the system used ancestors from a simpler environment as seeds. …
Fate Of 17Α-Estradiol, 17Β-Estradiol, And Estrone In Agricultural Soils And Sediments, Michael L. Mashtare Jr
Fate Of 17Α-Estradiol, 17Β-Estradiol, And Estrone In Agricultural Soils And Sediments, Michael L. Mashtare Jr
Open Access Dissertations
The shift to concentrated animal production facilities and increasing rural-urban migration has increased the localized land application of nearly 1 billion tons of manure and biosolids annually. Although these applications provide nutrients and contribute to soil tilth, they also serve as a source for an estimated 49 tons of the natural manure-borne estrogens, 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), and estrone (E1). While these estrogens are critical to endocrine systems, the low concentrations observed in the environment can disrupt endocrine function in non-target organisms, e.g., altering secondary sex characteristics which can lead to changes in wildlife communities.
Research presented here focuses on …
Developing White Ash With Resistance To The Emerald Ash Borer, Kaitlin Joy Palla
Developing White Ash With Resistance To The Emerald Ash Borer, Kaitlin Joy Palla
Open Access Theses
Hypocotyls isolated from mature embryos germinated on Murashige and Skoog (MS) medium supplemented with 22.2 µM 6-benzyladenine (BA) and 0.5 µM thidiazuron (TDZ) were transformed using Agrobacterium tumefaciens strain EHA105 harboring the pBI121-8D2 vector containing the neomycin phosphotransferase (nptII) gene and a full length, codon-optimized Bacillus thuringiensis Cry8Da protoxin gene (cry8D2). Explants were transformed in a bacterial suspension with 100 µM acetosyringone using 90 s sonication and 10 min vacuum-infiltration. Four independent lines of transformed shoots were selectively regenerated on MS medium with 22.2 µM BA, 0.5 µM TDZ, 50 mg L-1 adenine sulfate, 10% …
Habitat Restoration Of A Constructed Ohio River Embayment, Caleb Michael Rennaker
Habitat Restoration Of A Constructed Ohio River Embayment, Caleb Michael Rennaker
Open Access Theses
Backwater habitats of large rivers provide habitat for aquatic biota and influence important predator-prey interactions in fishes and other aquatic organisms. However, these areas often exhibit turbid conditions and lack habitat complexity. Restoration of lentic habitats through direct habitat manipulations has shown success in prior efforts, but these methods have not been tested in backwater habitats of large rivers. I attempted to create habitat in an Ohio River embayment by establishing founder colonies of aquatic macrophytes coupled with the placement of underwater gravel beds. I also evaluated the effects of total suspended solids (TSS) on overwintering structures of American Pondweed …