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 Decade: 2010-2019
 Collection: UNT Theses and Dissertations
9-Lipoxygenase Oxylipin Pathway in Plant Response to Biotic Stress

9-Lipoxygenase Oxylipin Pathway in Plant Response to Biotic Stress

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Date: May 2012
Creator: Nalam, Vamsi J.
Description: The activity of plant 9-lipoxygenases (LOXs) influences the outcome of Arabidopsis thaliana interaction with pathogen and insects. Evidence provided here indicates that in Arabidopsis, 9-LOXs facilitate infestation by Myzus persicae, commonly known as the green peach aphid (GPA), a sap-sucking insect, and infection by the fungal pathogen Fusarium graminearum. in comparison to the wild-type plant, lox5 mutants, which are deficient in a 9-lipoxygenase, GPA population was smaller and the insect spent less time feeding from sieve elements and xylem, thus resulting in reduced water content and fecundity of GPA. LOX5 expression is induced rapidly in roots of GPA-infested plants. This increase in LOX5 expression is paralleled by an increase in LOX5-synthesized oxylipins in the root and petiole exudates of GPA-infested plants. Micrografting experiments demonstrated that GPA population size was smaller on plants in which the roots were of the lox5 mutant genotype. Exogenous treatment of lox5 mutant roots with 9-hydroxyoctadecanoic acid restored water content and population size of GPA on lox5 mutants. Together, these results suggest that LOX5 genotype in roots is critical for facilitating insect infestation of Arabidopsis. in Arabidopsis, 9-LOX function is also required for facilitating infection by F. graminearum, which is a leading cause of Fusarium head ...
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Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

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Date: August 2013
Creator: Fogueri, Uma
Description: In this work we address two problems in computational chemistry relevant to biomolecular modeling. In the first project, we consider the conformer space of melatonin as a a representative example of “real-life” flexible biomolecules. Geometries for all 52 unique conformers are optimized using spin-component scaled MP2, and then relative energies are obtained at the CCSD (T) level near the complete basis set limit. These are then used to validate a variety of DFT methods with and without empirical dispersion corrections, as well as some lower-level ab initio methods. Basis set convergence is found to be relatively slow due to internal C-H…O and C-H…N contacts. Absent dispersion corrections, many DFT functionals will transpose the two lowest conformers. Dispersion corrections resolve the problem for most functionals. Double hybrids yield particularly good performance, as does MP2.5. In the second project, we propose a simple DFT-based diagnostic for nondynamical correlation effects. Aλ= (1-TAE [ΧλC]/TAE[XC])/λ where TAE is the total atomization energy, XC the “pure” DFT exchange-correlation functional, and ΧλC the corresponding hybrid with 100λ% HF-type exchange. The diagnostic is a good predictor for sensitivity of energetics to the level of theory, unlike most of the wavefunction-based diagnostics. For GGA functionals, Aλ values approaching unity ...
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American Blitzkrieg: Courtney Hodges and the Advance Toward Aachen (August 1 - September 12, 1944)

American Blitzkrieg: Courtney Hodges and the Advance Toward Aachen (August 1 - September 12, 1944)

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Date: December 2012
Creator: Rinkleff, Adam J.
Description: This is an analysis of combat operations of US First Army under the command of Courtney Hodges, between August 1 and September 12, 1944, with an emphasis upon 1st, 4th, 9th, and 30th Divisions. However, other formations are necessarily discussed in order to maintain context. Indeed, many historians have failed to emphasize the complex interdependent nature of these efforts, and the traditional narrative has been distorted by inadequate situational awareness. This study argues that the army's operations were exceedingly difficult, resulting in approximately 40,000 casualties over a six week period. Although historians claim that the Germans were essentially defeated by the end of July, and that the Allied advance was subsequently halted by logistical difficulties, the official combat records clarify that logistical shortages were a tertiary factor, as the enemy remained capable of strong resistance. Consequently, defensive efforts were the primary factor hindering the advance, in conjunction with deteriorating weather conditions, rugged terrain, and surprisingly severe traffic congestion. Although this was mobile warfare, military theorists have overestimated the effectiveness of mechanization and underestimated the potential for antitank defenses. Ultimately, this study asserts that First Army was the primary American combat formation, and historians have exaggerated the importance of George Patton's ...
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American Indian Worldviews, Risk Perceptions and Disaster Planning: an Exploratory Study

American Indian Worldviews, Risk Perceptions and Disaster Planning: an Exploratory Study

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Date: December 2013
Creator: Bales, Rodney A.
Description: It is commonly assumed that when confronted with an imminent hazard that people will react rationally, and prepare for, or at least attempt to avoid, danger from pending disasters. However, this conventional wisdom is not as evident as it appears. People prepare for, react to, or take social action to avoid hazards when they perceive the risk of danger to be threatening enough to warrant action, providing one has the will, insight and resources to do so. However, not all people perceive risks similarly. Risk is perceived differently by different people which affects risk perception and responses to hazards. This dissertation explores the relationships between American Indian worldviews, risk perceptions and disaster planning. To carry out this research 28 American Indians were interviewed. The sample consists of 14 American Indians residing in a rural are on the northern plains and 14 urban American Indians. The results only partially support that worldview is linked to risk perception and subsequent disaster planning. Other factors found to relate to risk perception and disaster planning for this non-representative sample of American Indians include various forms of social vulnerability.
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Americans Who Would Not Wait:  The American Legion of the Canadian Expeditionary Force, 1915-1917

Americans Who Would Not Wait: The American Legion of the Canadian Expeditionary Force, 1915-1917

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Date: August 2012
Creator: Smylie, Eric Paul
Description: This dissertation examines the five battalions of the Canadian Expeditionary Force designated as the American Legion. Authorized in Canada between 1915 and 1917, these units were formed to recruit volunteers from the United States to serve in the Canadian Overseas Contingent during the First World War. This work reviews the organization of Canada’s militia and the history of Anglo-American relations before examining the Canadian war effort, the formation of the American Legion, the background of its men, and the diplomatic, political, and constitutional questions that it raised. Much of the research focuses on the internal documents of its individual battalions (the 97th, 211th, 212th, 213th and 237th) and the papers of Reverend Charles Bullock now housed at the Public Archives of Canada. Documentation for the diplomatic furor the American Legion caused comes largely through the published diplomatic documents, British Foreign Office records held at the Public Record Office at Kew, and United States Department of State files at the National Archives at College Park, Maryland. The most useful sources for American Legion correspondence are the Beaverbrook papers held at the House of Lords Record Office, the papers of Canadian Prime Minister Sir Robert Laird Borden, and those of the Governor-General, ...
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Anchor Nodes Placement for Effective Passive Localization

Anchor Nodes Placement for Effective Passive Localization

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Date: August 2010
Creator: Pasupathy, Karthikeyan
Description: Wireless sensor networks are composed of sensor nodes, which can monitor an environment and observe events of interest. These networks are applied in various fields including but not limited to environmental, industrial and habitat monitoring. In many applications, the exact location of the sensor nodes is unknown after deployment. Localization is a process used to find sensor node's positional coordinates, which is vital information. The localization is generally assisted by anchor nodes that are also sensor nodes but with known locations. Anchor nodes generally are expensive and need to be optimally placed for effective localization. Passive localization is one of the localization techniques where the sensor nodes silently listen to the global events like thunder sounds, seismic waves, lighting, etc. According to previous studies, the ideal location to place anchor nodes was on the perimeter of the sensor network. This may not be the case in passive localization, since the function of anchor nodes here is different than the anchor nodes used in other localization systems. I do extensive studies on positioning anchor nodes for effective localization. Several simulations are run in dense and sparse networks for proper positioning of anchor nodes. I show that, for effective passive localization, the ...
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Aphorismen, Capriccio, and Heptameron for Piano Solo By Jürg Baur: a Performer's Guide

Aphorismen, Capriccio, and Heptameron for Piano Solo By Jürg Baur: a Performer's Guide

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Date: December 2012
Creator: Park, Esther
Description: The purpose of this dissertation is to give instruction regarding the performance of three important piano works by Jürg Baur (1918-2010). Aphorismen, Capriccio, and Heptameron stand out as his most significant piano works both because of their length and because of their pianistic complexity. Since Baur had a successful career as both teacher and composer during his lifetime, his acclaimed works received many honors in Germany. His works can be performed by intermediate to advanced students. Intermediate students can easily offer simpler pieces like Aphorismen in competitions, while pieces like Capriccio and Heptameron better are suited to a more advanced level. Although some of his compositions are difficult to perform compared with other modern German works, Baur's music is more accessible. In the article, "Auf der Spuren der alten Zeit" Baur is quoted to state that Paul Hindemith and Bela Bartok's music influenced his own compositional ideas. However, although Baur is a modern composer, he didn't write in a totally atonal style, but rather attempted to broaden tonality. While Heptameron is atonal, Aphorismen and Capriccio give the impression of tonality, thus they are more accessible to the audience. I was fortunate enough to study Aphorismen with Baur as well as ...
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Assessing Social Determinants of Severe Mental Illness in High-risk Groups

Assessing Social Determinants of Severe Mental Illness in High-risk Groups

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Date: May 2014
Creator: Sun, Qi
Description: The primary objective of this research was to explore the impact of possible social factors on non-institutionalized adults 18 years of age or older residing in the United States who exhibited severe mental illness (SMI). A holistic sociological model was developed to explain SMI by incorporating elements of social learning theory, social disorganization theory, and gender socialization theory with social demographic factors. Based on the holistic sociological model, the following factors were investigated: demographic aspects of age, education, income and gender; gender socialization; influence of neighborhood area; social network influence based on communication and interaction among peers and family members; and socially deviant behaviors such as frequently smoking cigarettes, drinking alcohol and using drugs specifically marijuana. The impact of these factors on SMI was examined. A sample of 206 respondents drawn from National Survey on Drug Use and Health, 2003 was assessed. These respondents had answered all the questions related to SMI; social deviant behaviors; neighborhood environment; and communications among peers, family members and friends; and the other studied factors. Ordinary linear regression with interaction terms was employed as a statistical tool to assess the impact of social determinants on SMI. Being female, living a disorganized neighborhood, and frequent and ...
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An Assessment of Consumers' Willingness to Patronize Foreign-Based Business Format Franchises: An Investigation in the Fast-Food Sector

An Assessment of Consumers' Willingness to Patronize Foreign-Based Business Format Franchises: An Investigation in the Fast-Food Sector

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Date: May 2010
Creator: Ertekin, Selcuk
Description: This study aimed to address consumers' stereotypical categorizations in the form of essentialist views about foreign cultures and their effect on individual consumers, including their negative or aroused emotions and subsequent retail patronage behaviors. The research mission was to empirically assess the salient dimensions of consumers' states of mind (positive and negative affect, psychological essentialism, epistemic curiosity), states of being (store atmospherics), and states of action (retail patronage behaviors) in a cultural context based on Mehrabian-Russell theory of environmental psychology. Specifically, the retail patronage setting was selected as foreign-based fast-food franchises because it represents both a relevant and timely situational context for consumer behavior. This dissertation makes several contributions to international retail patronage literature. First, it frames curiosity as an aroused emotional state and finds support for the relationship between consumer epistemic curiosity and retail patronage. Second, it provides support for the linkage between consumer affect and retail patronage in an international retail setting. Third, it reveals that affect has a greater impact on retail patronage than epistemic curiosity. The overarching finding of this study is an inability to tie the cultural elements in retail atmospherics, including signs, symbols, and artifacts, to consumer emotions. In addition, we were unable to ...
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Between Comancheros and Comanchería: a History of Fort Bascom, New Mexico

Between Comancheros and Comanchería: a History of Fort Bascom, New Mexico

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Date: August 2012
Creator: Blackshear, James Bailey
Description: In 1863, Fort Bascom was built along the Canadian River in the Eroded Plains of Territorial New Mexico. Its unique location placed it between the Comanches of Texas and the Comancheros of the Sangre de Cristo Mountains. This post was situated within Comanchería during the height of the United States Army's war against the Southern Plains Indians, yet it has garnered little attention. This study broadens the scholarly understanding of how the United States Army gained control of the Southwest by examining the role Fort Bascom played in this mission. This includes an exploration of the Canadian River Valley environment, an examination of the economic relationship that existed between the Southern Plains Indians and the mountain people of New Mexico, and an account of the daily life of soldiers posted to Fort Bascom. This dissertation thus provides an environmental and cultural history of the Canadian River Valley in New Mexico, a social history of the men stationed at Fort Bascom, and proof that the post played a key role in the Army's efforts to gain control of the Southern Plains Indians. This study argues that Fort Bascom should be recognized as Texas' northern-most frontier fort. Its men were closer to ...
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