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Environmental Philosophy and the Ethics of Terraforming Mars: Adding the Voices of Environmental Justice and Ecofeminism to the Ongoing Debate (open access)

Environmental Philosophy and the Ethics of Terraforming Mars: Adding the Voices of Environmental Justice and Ecofeminism to the Ongoing Debate

Questions concerning the ethics of terraforming Mars have received some attention from both philosophers and scientists during recent decades. A variety of theoretical approaches have been supplied by a number of authors, however research pursuant to this thesis has indicated at least two major blindspots in the published literature on the topic. First, a broad category of human considerations involving risks, dangers, and social, political, and economic inequalities that would likely be associated with efforts to terraform Mars have been woefully overlooked in the published literature to date. I attempt to rectify that oversight by employing the interpretive lens of environmental justice to address questions of environmental colonialism, equality in terms of political participation and inclusion in decision making structures, risks associated with technological progressivism, and responses to anthropogenic climate change. Only by including the historically marginalized and politically disenfranchised "voices," of both humans and nonhumans, can any future plan to terraform Mars be deemed ethical, moral or just according to the framework provided by environmental justice. Furthermore, broader political inclusion of this sort conforms to what ecofeminist author Val Plumwood calls the "intentional recognition stance" and provides an avenue through which globally societies can include nonanthropocentric considerations in decision …
Date: August 2013
Creator: French, Robert Heath
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Military-diplomatic Adventurism:  Communist China's Foreign Policy in the Early Stage of the Korean War (1950-1951) (open access)

Military-diplomatic Adventurism: Communist China's Foreign Policy in the Early Stage of the Korean War (1950-1951)

The thesis studies the relations of Communist China's foreign policy and its military offensives in the battlefield in Korean Peninsula in late 1950 and early 1951, an important topic that has yet received little academic attention. As original research, this thesis cites extensively from newly declassified Soviet and Chinese archives, as well as American and UN sources. This paper finds that an adventurism dominated the thinking and decision-making of Communist leaders in Beijing and Moscow, who seriously underestimated the military capabilities and diplomatic leverages of the US-led West. The origin of this adventurism, this paper argues, lays in the CCP's civil war experience with their Nationalist adversaries, which featured a preference of mobile warfare over positional warfare, and an opportunist attitude on cease-fire. This adventurism ended only when Communist front line came to the verge of collapse in June 1951.
Date: August 2013
Creator: Zhong, Wenrui
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Finding Terroir in Southwest Iowa (open access)

Finding Terroir in Southwest Iowa

Terroir combines the physical landscape of the vineyard with the grapevines and the methods and techniques used to produce wine from the grapes. This study used a GIS to identify the characteristics of the physical landscape in Pottawattamie, Mills, Montgomery, Fremont, and Page counties in southwestern Iowa. The components were combined in the GIS using a weighted linear index to identify areas suitable for vineyard development and to identify the general characteristics of the area. Vineyard owners were interviewed to help determine the weighting system to use in the GIS and to determine their perceptions of how the physical landscape impacts their vineyards, as well as to determine what grape varieties they plant in their vineyards and their decisions on making wine from these grapes. This information was collected to identify whether the vineyard owners had developed a sense of place for their vineyards and how this sense might aid them in the development of a terroir for their wines. The resulting perceptions about the individual wineries were then considered in conjunction with the results from the GIS modeling to understand how the physical landscape influences the concepts of sense of place and terroir in southwest Iowa. The physical landscape …
Date: August 2013
Creator: Deines, Dory
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Enemy of My Enemy Is What, Exactly? the British Flanders Expedition of 1793 and Coalition Diplomacy (open access)

The Enemy of My Enemy Is What, Exactly? the British Flanders Expedition of 1793 and Coalition Diplomacy

The British entered the War of the First Coalition against Revolutionary France in 1793 diplomatically isolated and militarily unprepared for a major war. Nonetheless, a French attack on the Dutch Republic in February 1793 forced the British to dispatch a small expeditionary force to defend their ally. Throughout the Flanders campaign of 1793, the British expeditionary force served London as a tool to end British isolation and enlist Austrian commitment to securing British war objectives. The 1793 Flanders campaign and the Allied war effort in general have received little attention from historians, and they generally receive dismissive condemnation in general histories of the French Revolutionary Wars. This thesis examines the British participation in the 1793 Flanders campaign a broader diplomatic context through the published correspondence of relevant Allied military and political leaders. Traditional accounts of this campaign present a narrative of defeat and condemn the Allies for their failure to achieve in 1793 the accomplishments of the sixth coalition twenty years later. Such a perspective obscures a clear understanding of the reasons for Allied actions. This thesis seeks to correct this distortion by critically analyzing the relationship between British diplomacy within the Coalition and operations in Flanders. Unable to achieve …
Date: August 2012
Creator: Jarrett, Nathaniel W.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Examining the Role of Latitude and Differential Insolation in Asymmetrical Valley Development (open access)

Examining the Role of Latitude and Differential Insolation in Asymmetrical Valley Development

Valley development through erosional processes typically tends to create symmetrical valleys. Over time, water cuts through the substrate to create valleys, gorges, and canyons for which the sides are the valley are evenly sloped. However, there are anomalies to this process. Asymmetrical valleys have been well-documented even in areas of uniform substrate or little tectonic uplift. One proposed explanation for the asymmetry of these valleys is differential insolation. This may lead to different microclimates from one slope to another which alter the rate and extent of erosion. Since the differences in received insolation vary with latitude (especially in streams that flow along an east/west axis), it follows that the degree of asymmetry should also vary with latitude if differential insolation is a primary driving factor in the development of these valleys. To evaluate if insolation plays a role in the development of asymmetrical valleys, this study examines variability in asymmetry across 447 valleys in nine study areas located at different latitudes. The degree of asymmetry for each valley was measured by using 30 meter resolution digital elevation models (DEMs) to determine the slope angle of each side of the valley. Asymmetry was measured by computing a ratio of the average …
Date: August 2013
Creator: Curran, Lorna L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Programming for the Latino Youth: a Content Analysis of Prime Time Television Programs By Three Spanish-language Broadcast Networks (open access)

Programming for the Latino Youth: a Content Analysis of Prime Time Television Programs By Three Spanish-language Broadcast Networks

This study reviews U.S. Spanish-language broadcast networks' prime time programming content targeted to the Latino youth audience. It explores the relationship between the Latino youth and prime time programming by Spanish-language broadcast networks and how they seek to attract this market as is reflected in the characteristics and quantity of their content and preferred formats by using the strategic management theory. This study identifies the amount and type of prime time programming that was catered to the Latino youth audience between 2003 and 2012 by the three major Spanish-language networks: Univision, Telemundo, and Telefutura. An observed pattern reveals that prime time programming targeting Latino teenagers is relatively smaller and older in comparison to programming delivered through the general programming.
Date: August 2013
Creator: Vazquez, Gabriel
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Comparative Phyto-uptake Across Distribution Coefficients of Pharmaceutical Compounds and Aquatic Macrophytes: Carbamazepine and Amiodarone Uptake in Lemna Spp (open access)

Comparative Phyto-uptake Across Distribution Coefficients of Pharmaceutical Compounds and Aquatic Macrophytes: Carbamazepine and Amiodarone Uptake in Lemna Spp

Few studies have been conducted on the effectiveness of phytoremediation of pharmaceutical compounds, although the persistent and non-acutely toxic nature of many of these compounds in today's water bodies may yield an ideal application for this practice. To quantify the potential effectiveness of plant uptake, kinetic and proportional bioconcentration factors (BCFk, and BCFp, respectively) in nanograms (ng) carbamazepine and amiodarone per gram (g) wet weight plant tissue for Lemna spp. were determined utilizing a 14-day continuous flow-through study. Samples were analyzed using isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) running in positive ion mode. Kinetic BCF was estimated at 0.538, while proportional BCF was estimated at 0.485. Kinetic BCF for the amiodarone study was estimated at 23.033, whereas proportional BCF was estimated at 41.340. Possible contamination of the C18 column and peristaltic pump failure may have impacted uptake results. In light of variability and current lack of research in the field, this work should be considered exploratory rather than conclusive.
Date: August 2013
Creator: Woodard, Jennifer Kristin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Repetition and Difference: Parodic Narration in Kander and Ebb's "The Scottsboro Boys" (open access)

Repetition and Difference: Parodic Narration in Kander and Ebb's "The Scottsboro Boys"

The American musical team John Kander and Fred Ebb created many celebrated works, yet musicologists have carried out little research on those works. This study examines the role of music in the parodic narration of Kander and Ebb's final collaboration, The Scottsboro Boys. Kander and Ebb use minstrelsy to tell the story of the historic Scottsboro Boys trials with actors portraying the Scottsboro Boys as minstrels; at the same time, they employ a number of devices to subvert minstrelsy stereotypes and thereby comment on racism. Drawing on African American literary theory, sociolinguistics, and Bakhtin's dialogism, this study illuminates how Signifyin(g), a rhetorical tradition used to encode messages in some African American communities, is the primary way the actors playing the Scottsboro Boys subvert through minstrelsy. This study not only contributes to the discussion of Signifyin(g) in African American musicals and theatre as a tool of subversion, but also provides an example of non-African American creators—Kander and Ebb—using Signifyin(g) devices. They use these in the music and the book; in particular, Kander and Ebb do some Signifyin(g) on Stephen Foster's plantation melodies.
Date: August 2013
Creator: Wolski, Kristin Anne
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Vehicle-collision Learning System Using Driving Patterns on the Road (open access)

A Vehicle-collision Learning System Using Driving Patterns on the Road

Demand of automobiles are significantly growing despite various factors, steadily increasing the average number of vehicles on the road. Increase in the number of vehicles, subsequently increases the risk of collisions, characterized by the driving behavior. Driving behavior is influenced by factors like class of vehicle, road condition and vehicle maneuvering by the driver. Rapidly growing mobile technology and use of smartphones embedded with in-built sensors, provides scope of constant development of assistance systems considering the safety of the driver by integrating with the information obtained from the vehicle on-board sensors. Our research aims at learning a vehicle system comprising of vehicle, human and road by employing driving patterns obtained from the sensor data to develop better systems of safety and alerts altogether. The thesis focusses on utilizing together various data recorded by the in-built embedded sensors in a smartphone to understand the vehicle motion and dynamics, followed by studying various impacts of collision events, types and signatures which can potentially be integrated in a prototype framework to detect variations, alert drivers and emergency responders in an event of collision.
Date: August 2013
Creator: Urs, Chaitra Vijaygopalraj
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Design and Application of Phased Array System (open access)

Design and Application of Phased Array System

Since its invention, phased array has been extensively applied in both military and civil areas. The applications include target detecting and tracking, space probe communication, broadcasting, human-machine interfaces, and remote sensing. Although the phased array applications show a broad range of potential market, there are some limitations of phased array's development: high cost, complex structure, narrow bandwidth, and high power consumption. Therefore, novel ideas are needed to reduce these constraints. In this thesis, several new approaches about the design and application of phased array are presents. First, the principle of phased array and fundamental design equations are introduced. Second, a new application of phased array antenna for radar respiration measurement is presented. By integrating a 4×4 Butler matrix with four-element antenna array, there will be four distinct main beams in radiation pattern. This new approach can improve the measurement accuracy and realize a high detecting rate. Third, a compact phased array antenna system based on dual-band operations is introduced. Dual-band function can make N-antenna system obtain 2N unique radiation beams (N is an integer) and achieve a significant size reduction compared to the conventional single-band system. To verify the design concept, a four-element phased array antenna working at 5GHz and …
Date: August 2013
Creator: Ren, Han
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Ideological Appropriation of La Malinche in Mexican and Chicano Literature (open access)

The Ideological Appropriation of La Malinche in Mexican and Chicano Literature

La Malinche is one of the most controversial figures in Mexican and Chicano literature. The historical facts about her life before and after the Spanish Conquest are largely speculative. What is reliably known is that she had a significant role as translator, which developed into something of mythic proportions. The ideological appropriation of her image by three authors, Octavio Paz, Laura Esquivel and Cherríe Moraga, are explored in this thesis. The full extent of the proposed rendition of La Malinche by Octavio Paz is the basis of the second chapter. The conclusion drawn by Paz, in The Labyrinth of Solitude (1950) is that La Malinche is what he calls la chingada [the raped/violated one] and proposes that all women are always open to conquest, sexually and otherwise. Laura Esquivel's novel Malinche (2006) is a re-interpretation that focuses on the tongue as the source of power and language as the ultimate source of autonomy for La Malinche. This aspect of La Malinche and the contrast of Paz's understanding are the basis of the third chapter of this thesis. Cherríe Moraga, in Loving in the War Years (1983), proposes that if women are to be traitors, it is not each other that …
Date: August 2013
Creator: Moriel Hinojosa, Rita Daphne
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Metabolic Engineering in Plants to Control Source/sink Relationship and Biomass Distribution (open access)

Metabolic Engineering in Plants to Control Source/sink Relationship and Biomass Distribution

Traditional methods like pruning and breeding have historically been used in crop production to divert photoassimilates to harvested organs, but molecular biotechnology is now poised to significantly increase yield by manipulating resource partitioning. It was hypothesized that metabolic engineering in targeted sink tissues can favor resource partitioning to increase harvest. Raffinose Family Oligosaccharides (RFOs) are naturally occurring oligosaccharides that are widespread in plants and are responsible for carbon transport, storage and protection against cold and drought stress. Transgenic plants (GRS47, GRS63) were engineered to generate and transport more RFOs through the phloem than the wild type plants. The transgenic lines produced more RFOs and the RFOs were also detected in their phloem exudates. But the 14CO2 labeling and subsequent thin layer chromatography analysis showed that the RFOs were most likely sequestered in an inactive pool and accumulate over time. Crossing GRS47 and GRS63 lines with MIPS1 plants (that produces more myo-inositol, a substrate in the RFO biosynthetic pathway) did not significantly increase the RFOs in the crossed lines. For future manipulation of RFO degradation in sink organs, the roles of the endogenous α-galactosidases were analyzed. The alkaline α-galactosidases (AtSIP1 and AtSIP2 in Arabidopsis) are most likely responsible for digesting RFOs …
Date: August 2013
Creator: Lahiri, Ipsita
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Study of Mechanisms to Engineer Fine Scale Alpha Phase Precipitation in Beta Titanium Alloy, Beta 21S (open access)

A Study of Mechanisms to Engineer Fine Scale Alpha Phase Precipitation in Beta Titanium Alloy, Beta 21S

Metastable b-Ti alloys are titanium alloys with sufficient b stabilizer alloying additions such that it's possible to retain single b phase at room temperature. These alloys are of great advantage compared to a/b alloys since they are easily cold rolled, strip produced and can attain excellent mechanical properties upon age hardening. Beta 21S, a relatively new b titanium alloy in addition to these general advantages is known to possess excellent oxidation and corrosion resistance at elevated temperatures. A homogeneous distribution of fine sized a precipitates in the parent b matrix is known to provide good combination of strength, ductility and fracture toughness. The current work focuses on a study of different mechanisms to engineer homogeneously distributed fine sized a precipitates in the b matrix. The precipitation of metastable phases upon low temperature aging and their influence on a precipitation is studied in detail. The precipitation sequence on direct aging above the w solvus temperature is also assessed. The structural and compositional evolution of precipitate phase is determined using multiple characterization tools. The possibility of occurrence of other non-classical precipitation mechanisms that do not require heterogeneous nucleation sites are also analyzed. Lastly, the influence of interstitial element, oxygen on a precipitation …
Date: August 2013
Creator: Behera, Amit Kishan
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Ultrafast Laser Sampling of a Plant Tissue and ion Conductivity Measurement for Investigation of Light Stress Generation Mechanisms (open access)

Ultrafast Laser Sampling of a Plant Tissue and ion Conductivity Measurement for Investigation of Light Stress Generation Mechanisms

In this study we applied ultra-short laser pulses on a biological sample (Arabidopsis), in order to cut it precisely in a square pattern and subsequently use it for studying stress generation mechanisms. For this purpose, we utilized femtosecond laser pulses at 100 fs pulse width and 80 MHz repetition rate. We took two processing parameters into consideration such as laser power, laser exposure time which is related to the stage speed. Therefore, we were able to find the laser optimum conditions for ablation of biological tissues. The mutant and wildtype (control) obtained from laser cutting with a size of 500 µm × 500 µm were directly transferred (in-situ with laser cutting) into a microfabricated chamber containing ~500 nanoliters deionized water for measuring ion conductivity. The ion conductivity is a signature of cell-death mechanisms caused by various stresses. A light with intensity of 100 µmol was exposed to the samples for 2 hours and 20 minutes as a source of stress. A quantitative electrical analysis with high accuracy was assured by utilizing a microchamber, which enables a measurement in nanoliter volume. We measured the impedance which is reciprocal of conductivity using a lock-in amplifier and a precise current source at frequency …
Date: August 2010
Creator: Abtahi, Seyed Ali
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Perspectives on Cultural Context: The Use of an Online Participatory Learning Environment as an Expansion of the Museum Visit (open access)

Perspectives on Cultural Context: The Use of an Online Participatory Learning Environment as an Expansion of the Museum Visit

Technology offers opportunities for museums to expand the ways in which cultural perspectives relevant to objects on display can be exchanged and understood. Multimedia content offered online in an environment with user input capabilities can encourage dialogue and enrich visitor experiences of museums. This action research project using narrative analysis was an effort to develop the use of web technology in museum education practice, with an emphasis on constructivist learning. Concepts including the visitor-centered museum and multiple narratives led the researcher to collaborate with a pre-service art teacher education classroom and a local Hindu community to create content that might better develop understandings of one museum's Hindu sculpture collection that are personal, cultural, and complex.
Date: August 2010
Creator: Sreenan, Patrick N.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Effective and Accelerated Informative Frame Filtering in Colonoscopy Videos Using Graphic Processing Units (open access)

Effective and Accelerated Informative Frame Filtering in Colonoscopy Videos Using Graphic Processing Units

Colonoscopy is an endoscopic technique that allows a physician to inspect the mucosa of the human colon. Previous methods and software solutions to detect informative frames in a colonoscopy video (a process called informative frame filtering or IFF) have been hugely ineffective in (1) covering the proper definition of an informative frame in the broadest sense and (2) striking an optimal balance between accuracy and speed of classification in both real-time and non real-time medical procedures. In my thesis, I propose a more effective method and faster software solutions for IFF which is more effective due to the introduction of a heuristic algorithm (derived from experimental analysis of typical colon features) for classification. It contributed to a 5-10% boost in various performance metrics for IFF. The software modules are faster due to the incorporation of sophisticated parallel-processing oriented coding techniques on modern microprocessors. Two IFF modules were created, one for post-procedure and the other for real-time. Code optimizations through NVIDIA CUDA for GPU processing and/or CPU multi-threading concepts embedded in two significant microprocessor design philosophies (multi-core design and many-core design) resulted a 5-fold acceleration for the post-procedure module and a 40-fold acceleration for the real-time module. Some innovative software modules, …
Date: August 2010
Creator: Karri, Venkata Praveen
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Hepatotoxicity of Mercury to Fish (open access)

Hepatotoxicity of Mercury to Fish

Tissue samples from spotted gar (Lepisosteus oculatus) and largemouth bass (Micropterus salmoides) were collected from Caddo Lake. Gar and bass livers were subjected to histological investigation and color analysis. Liver color (as abs at 400 nm) was significantly correlated with total mercury in the liver (r2 = 0.57, p = 0.02) and muscle (r2 = 0.58, p = 0.01) of gar. Evidence of liver damage as lipofuscin and discoloration was found in both species but only correlated with liver mercury concentration in spotted gar. Inorganic mercury was the predominant form in gar livers. In order to determine the role of mercury speciation in fish liver damage, a laboratory feeding study was employed. Zebrafish (Danio rerio) were fed either a control (0.12 ± 0.002 µg Hg.g-1 dry wt), inorganic mercury (5.03 ± 0.309 µg Hg.g-1 dry wt), or methylmercury (4.11 ± 0.146 µg Hg.g-1 dry wt) diet. After 78 days of feeding, total mercury was highest in the carcass of zebrafish fed methylmercury (12.49 ± 0.369 µg Hg.g-1 dry wt), intermediate in those fed inorganic mercury (1.09 ± 0.117 µg Hg.g-1 dry wt), and lowest in fish fed the control diet (0.48 ± 0.038 µg Hg.g-1 dry wt). Total mercury was …
Date: August 2010
Creator: Barst, Benjamin Daniel
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Functional Neural Toxicity and Endocrine Responses in Mice Following Naphthalene Exposure (open access)

Functional Neural Toxicity and Endocrine Responses in Mice Following Naphthalene Exposure

Polycyclic aromatic hydrocarbons (PAHs) are a well studied and diverse class of environmental toxicants. PAHs act via the aryl hydrocarbon receptor (AhR), and studies have suggested that PAHs may elicit neurological and estrogenic effects. Doses of PAHs between 50 to 150 ppm may elicit neurotoxicity in rodent models. The present study investigated the effects of naphthalene on in vivo steroidogenesis in Swiss Webster male mice, and in vitro neural function of Balb-C/ICR mice frontal cortex neurons. These data suggest that naphthalene may not elicit steroidogenic effects at concentrations ranging from 0.2 to 25 mg/kg/day, following a 7 day subcutaneous dosing regime. In addition, naphthalene may cause functional toxicity of frontal cortex neurons at concentrations of 32 to 160 ppm naphthalene.
Date: August 2010
Creator: Colbert, Crystal
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Life without Parole for Juvenile Offenders: Questions of Legality and Adolescent Culpability (open access)

Life without Parole for Juvenile Offenders: Questions of Legality and Adolescent Culpability

Life without parole for juvenile offenders is a controversial issue across the globe. Recently, the United States stands alone as the only country in the world that allows juvenile offenders to be sentenced to life time confinement without the possibility of parole. Furthermore, the U.S. has seen an increase in juvenile waivers and blended sentences, which has resulted in harsher penalties for juvenile offenders who have committed serious and violent crimes. This analysis examines scientific evidence that shows juveniles are different from adults in terms of brain development, rational decision making abilities, and maturity levels. These findings have questioned the reasoning behind imposing adult punishment on adolescent behavior. This analysis also presents the legal arguments suggesting that juvenile life without parole is unconstitutional and violates the Eighth and Fourteenth Amendments. Arguments for and against life sentences were also presented. This study concludes with a discussion of policy implications, whether the U.S. Supreme Court should abolish juvenile life without parole sentencing practices and explores the possible future direction of juvenile sentencing in the United States.
Date: August 2010
Creator: Corrington, David L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Interactions of N-Acylethanolamine Metabolism and Abscisic Acid Signaling in Arabidopsis Thaliana Seedlings (open access)

Interactions of N-Acylethanolamine Metabolism and Abscisic Acid Signaling in Arabidopsis Thaliana Seedlings

N-Acylethanolamines (NAEs) are endogenous plant lipids hydrolyzed by fatty acid amide hydrolase (FAAH). When wildtype Arabidopsis thaliana seeds were germinated and grown in exogenous NAE 12:0 (35 µM and above), growth was severely reduced in a concentration dependent manner. Wildtype A. thaliana seeds sown on exogenous abscisic acid (ABA) exhibited similar growth reduction to that seen with NAE treatment. AtFAAH knockouts grew and developed similarly to WT, but AtFAAH overexpressor lines show markedly enhanced sensitivity to ABA. When low levels of NAE and ABA, which have very little effect on growth alone, were combined, there was a dramatic reduction in seedling growth in all three genotypes, indicating a synergistic interaction between ABA and NAE. Notably, this synergistic arrest of seedling growth was partially reversed in the ABA insensitive (abi) mutant abi3-1, indicating that a functional ABA signaling pathway is required for the full synergistic effect. This synergistic growth arrest results in an increased accumulation of NAEs, but no concomitant increase in ABA levels. The combined NAE and ABA treatment induced a dose-dependent increase in ABI3 transcript levels, which was inversely related to growth. The ABA responsive genes AtHVA22B and RD29B also had increased expression in both NAE and ABA treatment. …
Date: August 2010
Creator: Cotter, Matthew Q.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Determining the Relation Between the Moments of Acquisition of Baseline Conditional Discriminations and the Emergence of Equivalence Relations (open access)

Determining the Relation Between the Moments of Acquisition of Baseline Conditional Discriminations and the Emergence of Equivalence Relations

The experiment was an attempt to gain a more precise understanding of the temporal relation between the development of analytic units and equivalence relations. Two prompting procedures were used during training to pinpoint when eight subjects learned the conditional discriminations. Near simultaneous presentation of probe and training trials allowed for examination of the temporal relation between conditional discrimination acquisition and derived performances on stimulus equivalence probes. The data show that, for seven of eight subjects, a decreased reliance on prompts was coincident with the development of equivalence-consistent choices on either all or some probe trials, which suggests that the development of analytic units is sufficient to give rise to equivalence relations among stimuli.
Date: August 2010
Creator: Swisher, Melissa J.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Literature in the Age of Science: Technology and Scientists in the Mid-Twentieth Century Works of Isaac Asimov, John Barth, Arthur C. Clarke, Thomas Pynchon, and Kurt Vonnegut (open access)

Literature in the Age of Science: Technology and Scientists in the Mid-Twentieth Century Works of Isaac Asimov, John Barth, Arthur C. Clarke, Thomas Pynchon, and Kurt Vonnegut

This study explores the depictions of technology and scientists in the literature of five writers during the 1960s. Scientists and technology associated with nuclear, computer, and space science are examined, focusing on their respective treatments by the following writers: John Barth, Kurt Vonnegut, Thomas Pynchon, Isaac Asimov, and Arthur C. Clarke. Despite the close connections between the abovementioned sciences, space science is largely spared from negative critiques during the sixties. Through an analysis of Barth's Giles Goat-boy, Vonnegut's Cat's Cradle, Pynchon's The Crying of Lot 49, Asimov's short stories "Key Item," "The Last Question," "The Machine That Won the War," "My Son, the Physicist," and Clarke's 2001: A Space Odyssey, it is argued that altruistic goals of space science during the 1960s protect it from the satirical treatments that surround the other sciences.
Date: August 2010
Creator: Simes, Peter A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Optimism, Delay Discounting, and Physical Exercise: The Role of Delay Discounting on Individual Levels of Exercise (open access)

Optimism, Delay Discounting, and Physical Exercise: The Role of Delay Discounting on Individual Levels of Exercise

Deciding to exercise requires trade-offs between immediate and delayed benefits. These momentary decisions may be moderated by personality such that patterns of individual behavior emerge. The aim of the current study was to determine if higher levels of optimism and lower levels of delay discounting were related to exercise frequency. A sample of 360 undergraduate students completed a survey study related to understanding the choices made by undergraduates and how other factors relate to their decision-making. The survey included measures of optimism, delayed discounting, and self-reported exercise frequency in four domains: cardiovascular, resistance, sports, active lifestyle. Hierarchical linear regression was used to examine optimism and delay discounting as predictors of exercise frequency. Optimism and delay discounting were negatively correlated, but neither was related to exercise frequency. Furthermore, optimism and delay discounting were not significantly related to frequency spent in cardiovascular, resistance, or active lifestyle exercise. However, women scoring higher in delay discounting were more likely to participate in physical sports. The present study helps inform future research by showing potentially important psychosocial variables related to optimism, delay discounting, and exercise.
Date: August 2010
Creator: Smith, Lauren Marie
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Cold-Formed Steel Bolted Connections Using Oversized and Slotted Holes without Washers (open access)

Cold-Formed Steel Bolted Connections Using Oversized and Slotted Holes without Washers

In cold-formed steel (CFS) construction, bolted connections without washers for either oversized or slotted holes may significantly expedite the installation process and lower the cost. However, the North American Specification (AISI S100, 2007) for the Design of Cold-Formed Steel Structural Members requires washers to be installed in bolted connections with oversized or slotted holes. A research project (Phase 1) sponsored by American Iron and Steel Institute (AISI) was recently completed at the University of North Texas (UNT) that investigated the performance and strength of bolted CFS connections with oversized and slotted holes without using washers. The research presented in this thesis is the Phase 2 project in which the bolted CFS connections were studied in a broader respect in terms of the failure mechanism, the material thickness, and the hole configurations. Single shear and double shear connections without washers using oversized holes, oversized combined with standard or slotted holes were experimentally examined. Combined with Phase 1 results, the Phase 2 gives a comprehensive evaluation of the behavior and strength of bolted CFS connections with oversized and slotted holes without using washers. Revisions to the existing AISI North American Specification requirements for bolted connections are proposed to account for the reduction …
Date: August 2010
Creator: Xu, Ke
Object Type: Thesis or Dissertation
System: The UNT Digital Library