Physical Sciences and Mathematics Commons^™

Secondary Structure Prediction Of Long Rna Sequences Based On Inversion Excursions And A Modularized Mapreduce Framework, Daniel Tesfai Yehdego

Open Access Theses & Dissertations

Ribonucleic acid (RNA) molecules and their secondary structures play important roles in many biological processes including gene expression and regulation. The genomes of many viruses are also RNA molecules. Since secondary structures are crucial for RNA functionality, computational predictions of the RNA secondary structures have been widely studied. However, the tremendous demands on computer memory and computing time for complex secondary structures limit the capability of existing thermodynamically based algorithms for structure predictions to handling only short RNA sequences with a few hundred bases. One approach to overcome this limitation is by first cutting long RNA sequences into shorter, non-overlapping …

Sensitivity Analysis Of Streambed Leakance Downstream Of Caballo Reservoir, Derrick Ohara

Open Access Theses & Dissertations

Modeling transient effects of streams near well fields is an important tool for understanding water balance within the Rio Grande Project (Project). The results are known as stream leakage. Stream leakage quantifies the amount of water seeping from a stream, canal and/or drain to/from a well field. Stream leakages near the Canutillo Well field, primary river losses for years 2005 through 2010 along with historical gain/losses and allocations of surface water with the associated agreements were evaluated.

The overall loss rates per mile in the Project for years 2005 to 2010 averaged -0.75 cubic feet per second (cfs). The historical …

Generalized Linear Latent Mixed Modeling Of Functional Independent Measures And Patient Outcomes, Maduranga Kasun Dassanayake

Open Access Theses & Dissertations

The Functional Independent Measure (FIM) is one of the most widely accepted functional assessment measures used in the rehabilitation community. Past research studies have investigated the relationship between place of discharge, admission FIM scores or FIM difference scores, and patients' characteristics and found relationships between those variables. However, most of these studies fail to account for the multi-layered multidimensionality of the FIM and the measurement error associated with the FIM items. This study utilizes Generalized Linear Latent Mixed Models (GLLAMM) and Structural Equation Models (SEM) to assess which patient characteristics are associated with FIM difference scores and the structural relationship …

The Impact Of Solar Radiation On The Distribution Of The Red Imported Fire Ant, Solenopsis Invicta (Hymenoptera: Formicidae), Audrey Marie Hernando

Open Access Theses & Dissertations

This dissertation investigates the role of solar radiation on Solenopsis invicta, the red imported fire ant. This ant is considered a serious invasive pest in the southern United States. Four Texas cities where fire ants are found were studied: San Antonio, Corpus Christi, Wichita Falls, and the outlier, Lubbock. Shade angles were measured in eight compass directions within plots located along eight transect directions around buildings. Using the shade angle, solar radiation for different times of day and seasons were calculated. All of the cities were on the same precipitation isocline with the exception of Lubbock, Texas. The number of …

A Survey Of Selected Pharmaceuticals And Personal Care Products In A Binational River And Their Effects On A Member Of Its Zooplankton Community, Plationus Patulus (Rotifera), Diana Angelica Martinez Gomez

Open Access Theses & Dissertations

The presence of 9 selected PPCPs (acetaminophen, caffeine, cotinine, codeine, fluoxetine, erythromycin, ciprofloxacin, sulfamethazine, and trimethoprim) was surveyed in water samples collected at four sites along the middle Rio Grande during two flow regimes (irrigation and non-irrigation). Water collection for PPCPs analyses were conducted from August 2010 through September 2011. Three of the sites were located upstream, in, and downstream of the El Paso, TX/Ciudad Juárez, MX metroplex. Site selection was based on their proximity to the metroplex and due to the fact that the Rio Grande in this region is an effluent receiver water system (IBWC, 2011). The fourth …

The Impact Of Decadal Land Cover Change On The Global Warming Potential Of Beringian Arctic Tundra, David Hwei-Len Lin

Open Access Theses & Dissertations

Arctic terrestrial ecosystems play an important role in the global carbon cycle. If arctic warming continues to rise as projected, large amounts of soil carbon stored in these ecosystems could be released to the atmosphere as carbon dioxide or methane and positively enhance greenhouse warming. Thus, improving understanding of the likely future state and fate of arctic soil carbon, and the carbon uptake potential of arctic terrestrial ecosystems are well recognized research priorities.

At the pan-arctic scale, decadal increases in NDVI (Normalized Difference Vegetation Index), an index of vegetation productivity, have been observed from satellite imagery, indicating a general greening …

Implications Of Decade Time Scale Arctic Plant Community Change On Ecosystem Function, Mark Jason Lara

Open Access Theses & Dissertations

Almost half the global soil organic carbon pool is found in northern high latitudes. The majority of this soil carbon is stored in a greenhouse inert state within permafrost. As pronounced warming of high northern latitudes ensues, there is a strong likelihood that this substantial soil organic carbon pool will be mobilized to the atmosphere where it is likely to positively enhance greenhouse warming. Modeling studies suggest this positive feedback could alter future climate states of the Arctic and the globe, and affect how humans may need to adapt to climate change. Accordingly, understanding the patterns and controls and the …

Recent Changes In The Growth And Nutrient Limitation Of Benthic And Pelagic Algae In Arctic Tundra Ponds, Christina Hernandez

Open Access Theses & Dissertations

Arctic ponds are a dominant feature in Barrow, Alaska. Ponds may function as carbon sinks during the growing season from production of photosynthetic organisms like algae; however, little work has been done on this topic. Environmental changes have been occurring in the Arctic stemming from climate change and human perturbations. The focus of this study was to assess a historically studied region for changes in algal primary production that may have been produced due to increases in temperature over the past 40 years and increased human development. Additionally, this study aimed to determine nutrient limitation of algal production in the …

Biological Effects Of Copper On Prosopis Pubescens (Screw Bean Mesquite), Marian Nicte Zappala

Open Access Theses & Dissertations

Phytoremediation is an emerging technology for cleaning industrial and urban contamination (Peuke and Rennenberg, 2005). Many factors including germination rate, biomass changes, biochemical changes, and nutrient changes must be determined in order to utilize a plant for phytoremediation. Our results showed that Prosopis pubescens (Screw bean mesquite) is a hyperaccumulator of copper from copper sulfate and a feasible option to remediate fields with up to 200 ppm of copper sulfate.

Screw bean mesquite seeds are viable even after 30 years of storage. Both copper sulfate and copper nitrate decreased the germination rate of screw bean mesquite seeds. In soil grown …

Microelement Localization In Leaves Of Populus Spp. And Tolerance Mechanisms To Boron-Salt Toxicity, Daniel Arriaga

Open Access Theses & Dissertations

Phytoremediation has been proposed as a low-cost, environmentally friendly alternative to clean highly contaminated sites. Phytoremediation using trees offer the advantage of metal immobilization (phytostabilization), high hydraulic pumping pressures, produce large plant biomass, absorption of total dissolved salts within their tissue, long life spans, less frequent irrigation and, a massive root system that helps soil attachment. Hybrid poplar varieties are long-lived, perennial, fast growing, and produce a large amount of foliage to harvest. Boron is an essential micronutrient for plants. Certain locations, such as California and Turkey, have suffered from high boron efflux from irrigation waters. It has been identified …

An Assessment Of Land Cover Change At The Indio Mountains Research Station, Rebecca Anne Escamilla

Open Access Theses & Dissertations

Land cover change is a significant contributor to environmental change on a global scale. In the arid regions of the southwest US, shrub encroachment is one of the most important forms of land cover change. Many factors contribute to shrub encroachment, which can impact structure and function. In the Chihuahuan Desert, mountain ecosystems are known as biodiversity hotspots and are especially susceptible to environmental change making them useful indicators of global change. The overarching goal of this dissertation is to improve i) understanding of land cover change in a Chihuahuan Desert mountain landscape, and ii) how knowledge of land cover …