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open access

Bacterial Challenge in Lumbricus Terrestris: A Terrestrial Invertebrate Immunotoxicity Model.

Description: A bacterial challenge assay was developed utilizing the earthworm, Lumbricus terrestris, in order to assess potential immunotoxic effects from exposure to specific polychlorinated biphenyl congeners. Earthworms were inoculated with Aeromonous hydrophila, establishing a 10-day LD50. In vitro assays for effects of PCBs on phagocytosis agreed with mammalian studies, demonstrating potent suppression of phagocytosis by the non-coplanar PCB congener 138 and no suppression by the coplanar congener 126. However, when the effects of the two PCB congeners were evaluated for suppression of resistance to a whole animal infection challenge assay, coplanar PCB 126 decreased the ability of L. terrestris to withstand infection while non-coplanar PCB 138 did not.
Date: May 2007
Creator: McDonald, Jennifer C.
Partner: UNT Libraries
open access

The use of democratic institutions as a strategy to legitimize authoritarian rule.

Description: Numerous authoritarian states use institutions usually associated with democratic regimes like a constitution, elections, and a legislature. This seems to be counterintuitive. Authoritarian regimes should rather shrink away from democratic institutions. Elections can be won by the opposition and legislatures can make decisions against the interests of the ruler. So, why do autocratic regimes install institutions which limit their power and threaten their survival in office? Assuming actors behave rationally, one should expect authoritarian rulers only to introduce procedures working in their favor. This study looks at the effect of institutions in authoritarian regimes. The findings suggest that legislatures significantly lower the chances of regime breakdown in the long run. However, particularly in election years, authoritarian regimes are facing a higher likelihood of failure.
Date: May 2007
Creator: Michalik, Susanne
Partner: UNT Libraries
open access

The Geologic and Archaeological History of the Dickie Carr Site 41PR26

Description: This thesis is an analysis and synthesis of the geologic and archaeological history of the Dickie Carr site, 41PR26, on Mill Creek in north central Texas. Included are analyses of the stratigraphy, sedimentary environments, and soils of the locality. A regional comparison is made with respect to the Late Quaternary geology of the upper Trinity River basin, Texas to interpret the geologic data. Two stratigraphic units were identified that record the Pleistocene-Holocene transition. The buried lower unit is comprised of terrace, floodplain, and channel deposits with extensive pedogenesis. The unit is Late Pleistocene in age and contains the remains of Mammuthus columbi. The upper stratigraphic unit is comprised of terrace and floodplain sediments with well-expressed pedogenesis. The unit is Early Holocene in age with Late Paleoindian and Late Archaic occupations. The archaeological components are compared and contrasted with documented sites from the Elm and East Forks of the Trinity River. The occupations are examined in a geoarchaeological context. The Late Paleoindian occupation is post-depositional and located in terrace deposits. The Late Archaic occupation is syndepositional and located in floodplain deposits.
Date: May 2007
Creator: Byers, Johnny A.
Partner: UNT Libraries
open access

Determining Properties of Synaptic Structure in a Neural Network through Spike Train Analysis

Description: A "complex" system typically has a relatively large number of dynamically interacting components and tends to exhibit emergent behavior that cannot be explained by analyzing each component separately. A biological neural network is one example of such a system. A multi-agent model of such a network is developed to study the relationships between a network's structure and its spike train output. Using this model, inferences are made about the synaptic structure of networks through cluster analysis of spike train summary statistics A complexity measure for the network structure is also presented which has a one-to-one correspondence with the standard time series complexity measure sample entropy.
Date: May 2007
Creator: Brooks, Evan
Partner: UNT Libraries
open access

An examination of the effects of accuracy+rate versus accuracy+observing response training methods on matching-to-sample performance.

Description: The relative efficacy of training procedures emphasizing accuracy versus those which add a rate criterion is a topic of debate. The desired learning outcome is fluent responding, assessed by measures of retention, endurance, stability, and application. The current study examined the effects of these two procedures on fluency outcomes using a matching-to-sample paradigm to train participants to match English to Japanese characters. An explicit FR-3 observing response was added to an accuracy-only condition to assess the extent to which it may facilitate learning. Total time spent responding in practice drills in accuracy-only conditions was yoked to total time spent in drills achieving rate aims in accuracy+rate (AR) conditions. One participant clearly demonstrated superior fluency outcomes after AR training while another displayed superior endurance and stability outcomes after such training. The remaining two participants did not demonstrate significantly different fluency outcomes across conditions.
Date: May 2007
Creator: Anderson, Jesse
Partner: UNT Libraries
open access

Study of Substituted Benzenesulfonate-Containing Layered Double Hydroxides and Investigation of the Hexamethylenetetramine Route of LDH Synthesis

Description: Benzenesulfonates, para-substituted with amine, chloride and methyl groups were successfully incorporated into layered double hydroxides of two different compositions, 2:1 Mg-Al LDH and 2:1 Zn-Al LDH. These parent materials were also doped with small amounts of nickel and the differences in the two systems were studied. The hexamethylenetetramine route of layered double hydroxide synthesis was investigated to verify if the mechanism is indeed homogeneous. This included attempting preparation of 2:1 Mg-Al LDH, 2:1 Zn-Al LDH and 2:1 Zn-Cr LDH with two different concentrations of hexamethylenetetramine. The analytical data of the products suggest that the homogeneous precipitation may not be the true mechanism of reaction involved in LDH synthesis by this method.
Date: May 2007
Creator: Ambadapadi, Sriram
Partner: UNT Libraries
open access

Lining Up

Description: A creative, multi-genre collection that includes three personal essays (non-fiction) and two short stories (fiction). The pieces in this collection primarily focus on the themes of loneliness and waiting. It includes pieces dealing with homosexual relationships, friendships and heterosexual relationships. Collection includes the essays "The Line," "Why We Don't Talk about Christmas," and "Boys Who Kiss Back," and includes the short stories "I Am Allowed to Say Faggot" and "Dear Boy."
Date: May 2007
Creator: Davis, Allegra
Partner: UNT Libraries
open access

Hindrance of the Myosin Power Stroke Posed by the Proximity to the Troponin Complex Identified Using a Novel LRET Fluorescent Nanocircuit

Description: A novel luminescence resonance energy transfer (LRET) nanocircuit assay involving a donor and two acceptors in tandem was developed to study the dynamic interaction of skeletal muscle contraction proteins. The donor transmits energy relayed to the acceptors distinguishing myosin subfragment-1 (S1) lever arm orientations. The last acceptor allows the detection of S1's bound near or in between troponin complexes on the thin filament. Additionally, calcium related changes between troponin T and myosin were detected. Based on this data, the troponin complex situated every 7 actin monomers, hinders adjacently bound myosins to complete their power stroke; whereas myosins bound in between troponin complexes undergo complete power strokes.
Date: May 2007
Creator: Coffee Castro-Zena, Pilar G.
Partner: UNT Libraries
open access

Conditional Discrimination and Stimulus Equivalence: Effects of Suppressing Derived Symmetrical Responses on the Emergence of Transitivity.

Description: Symmetry suppression was conducted for five subjects who demonstrated a tendency to derive equivalence relations based on conditional discrimination training in a match-to-sample procedure. Symmetry suppression was applied in three consecutive sessions in which symmetrical responses were suppressed for one stimulus class in the first condition, two stimulus classes in the second condition, and all three stimulus classes in the final condition. Symmetry suppression slowed the emergence of transitivity for two subjects and prevented it for the other three. Results indicated that unplanned features of stimulus configurations emerged as discriminative variables that controlled selection responses and altered the function of consequent stimuli. Disruption of cognitive development by conflicting contingencies in natural learning environments is discussed.
Date: May 2007
Creator: Jones, Aaron A.
Partner: UNT Libraries
open access

Skylab: The Human Side of a Scientific Mission

Description: This work attempts to focus on the human side of Skylab, America's first space station, from 1973 to 1974. The thesis begins by showing some context for Skylab, especially in light of the Cold War and the “space race” between the United States and the Soviet Union. The development of the station, as well as the astronaut selection process, are traced from the beginnings of NASA. The focus then shifts to changes in NASA from the Apollo missions to Skylab, as well as training, before highlighting the three missions to the station. The work then attempts to show the significance of Skylab by focusing on the myriad of lessons that can be learned from it and applied to future programs.
Date: May 2007
Creator: Johnson, Michael P.
Partner: UNT Libraries
open access

Women's Gender Role Attitudes: Association of Demographic Characteristics, Work Related Factors, and Life Satisfaction

Description: Factors related to women's gender role attitudes were assessed using data from a national survey in 1988 in which 3,507 members of the Young Women cohort were interviewed by phone. The demographic characteristics were education, age, marital status, and region of residence. Older women, married women, and those of Southern residence were hypothesized to have traditional gender role attitudes. These hypotheses were supported by the data (p &tn; .05, p &tn; .05, p &tn; .01, respectively). As hypothesized, those with high educational levels (p &tn; .01) had egalitarian attitudes. Four work related variables (labor force participation, hours worked at one's paid position, personal income, and earnings as percent of total family income) were hypothesized to relate to non-traditional gender role attitudes. Job dissatisfaction was hypothesized to relate to traditional gender role attitudes. Personal income (p &tn; .01) was related to non-traditional gender role attitudes. There was no relationship between labor force participation and hours worked at one's position and gender role attitudes. Percent of total family income (p &tn; .01) was related to traditional gender role attitudes, not egalitarian attitudes, and, as hypothesized, job dissatisfaction (p &tn; .05) was related to traditional gender role attitudes. Life dissatisfaction was hypothesized to relate to egalitarian attitudes; however (p &tn; .01) was associated with traditional, not egalitarian, gender role attitudes. When exploring practical reasons for women working, a negative relationship was found between Southern (p &tn; .01) residence and labor force participation (p &tn; .01) and practical reasons for women working. Higher educational levels (p &tn; .01) were positively related.
Date: May 2007
Creator: Lee, Audra
Partner: UNT Libraries
open access

Children of Incarcerated Parents: An Application of the Stress Process Model.

Description: The purpose of this qualitative interview study is to examine the lives and experiences children of incarcerated parents from a theoretical perspective through an application of the social stress process. Previous research on children of incarcerated parents has neglected to add a theoretical component to their research, which is the intention of this research. The results will be organized around the theoretical domains of the stress process applied to findings from the analysis of eleven qualitative interviews of mothers and/or caregivers of youth(s) of an incarcerated parent. Guided by analytic induction, the themes that emerged from the transcripts were applied to the theoretical propositions of the social stress process: stressors, mediators, and manifestations. Stressors experienced by children of incarcerated parents include: the incarceration of a parent, financial difficulties, and residential instability. Stress mediators include: coping mechanisms and the importance of maintaining familial ties during parental incarceration. The manifestations or outcomes include: internalizing and externalizing behaviors.
Date: May 2007
Creator: Jarvis, Ashley
Partner: UNT Libraries
open access

Analyzing the Effects of a Performance Pay Plan on Manager Performance in an Accounting Firm

Description: This study examined the effect of a score card¬-based performance pay plan in a professional services firm. The plan was implemented in response to a decreasing trend in productivity and a desire for a formal incentive compensation plan. Performance of manager and senior manager accountants were analyzed across two departments over a five year period. A definitive account of the effects of the intervention is limited by the case-¬study design, but the data does suggest that the performance pay plans used did not adversely affect performances. Design limitations of the plan and future research are also discussed.
Date: May 2007
Creator: McDaniel, Sarah Curran
Partner: UNT Libraries
open access

Toward a philosophy of water: Politics of the pollution and damming along the Ganges River.

Description: This thesis sets out to develop a beginning of a philosophy of water by considering philosophical implications of ecological crises currently happening along the waters of the Ganges River. In my first chapter, I give a historical account of a philosophy of water. In my second chapter, I describe various natural and cultural representations of the Ganges, accounting for physical features of the river, Hindu myths and rituals involving the river, and ecological crises characterized by the pollution and damming of the river. In my third and final chapter, I look into the philosophical implications of these crises in terms of the works of the contemporary philosopher Bruno Latour.
Date: May 2007
Creator: McAnally, Elizabeth Ann
Partner: UNT Libraries
open access

May 1856: Southern Reaction to Conflict in Kansas and Congress

Description: This thesis examines southern reactions to events that occurred in May 1856: the outbreak of civil war in Kansas and the caning of Senator Charles Sumner of Massachusetts. I researched two newspapers from the upper South state of Virginia, the Richmond Enquirer and the Richmond Daily Whig, and two newspapers from the lower South state of Louisiana, the New Orleans Times-Picayune and the New Orleans Bee to determine the extent to which political party sentiment and/or geographic location affected southern opinion towards the two events. Political party ties influenced the material each newspaper printed. Each newspaper worried that these events endangered the Union. Some, however, believed the Union could be saved while others argued that it was only a matter of time before the South seceded.
Date: May 2007
Creator: Fossett, Victoria Lea
Partner: UNT Libraries
open access

Mama D's 2 Blocks: A Documentary Film

Description: Mama D's 2 Blocks tells the story of a neighborhood home in New Orleans that was transformed into a distribution center and used to assist residents impacted by Hurricane Katrina's devastation in 2005. Mama D stayed at her home throughout the storm and remained there until the floodwaters had subsided. After the water had drained, socially minded youth from all over the country were drawn to Mama D's home and stayed there while supporting local renewal efforts. The film documents their joining together, without electricity or running water, and assisting in the rebuilding process undertaken by Mama D and other neighborhood residents. This film captures a community in action, how it survived, and the first steps taken towards the rebuilding of New Orleans.
Date: May 2007
Creator: Ferris, Mika
Partner: UNT Libraries
open access

Distances

Description: I provide in my preface a brief account of my development as a creative writer. Through this development I draw an analogy to the evolution of modern science by stating that my need for personal clarity is analogous to the charge for empirical clarity of modern science. Furthermore, I contrast the objectivism of modern science to the subjectivism of creative writing. The four short stories in my thesis range from a semi-autobiographical story, to two short stories that stem out further and further from the subjective origin of the first story. The story of greatest distance is “Fireflies,” which is not semi-autobiographical, but pure fiction. The final short story returns to the subjective origin of the first. The drive of Distances is thereby to create a sort parabola: a subjective, semi-autobiographical origin, to an objective, purely fictional crest, then a return to that subjective, semi-autobiographical origin. The entire collection is a holistic, ultimately subjective, and therefore personal experience; yet, through the use certain tropes,metaphors others can relate to, the stories are paradoxically sharable.
Date: May 2007
Creator: Esteves, Jason
Partner: UNT Libraries
open access

Reality Television: Using Para-Social Relationship Theory and Economic Theory to Define the Success of Network Reality Programming

Description: This study seeks to use a dual-theoretical approach, through the use of para-social relationship theory and economic data analysis, to explain the success of reality television since the early 2000s. This study uses both qualitative and quantitative components to understand the growth of reality television. This study includes a literature analysis of both methodologies used. Focus groups were used to seek to find a strong level of para-social interaction in viewers of reality television. Two focus groups were conducted with participants 18-35. There were a total of 16 participants who attended the focus group sessions. The information collected suggested that viewers of reality television formed para-social relationships. It appeared that female viewers were more likely to form para-social relationships than male viewers.
Date: December 2010
Creator: Dyer, Caitlin Elizabeth
Partner: UNT Libraries
open access

From Outward Appearance to Inner Reality: A Reading of Aaron Copland's Inscape

Description: About 8.3% of individuals diagnosed with diabetes mellitus (DM) are diagnosed with comorbid depression, a higher rate than the general adult population. This project examined the differences of depression symptoms experienced between diabetic and matched non-diabetic individuals and the relationship of daily activity and nutrition behaviors with depression between these groups. The 2005-2006 National Health and Nutrition Examination Survey (NHANES) was utilized to assess: depression symptoms, diabetic glycemic control as measured by glycoginated hemoglobin (HbA1c), amount of physical activity, percentage of macronutrients, daily frequencies of foods consumed, and the use of nutritional food labels to make food choices. A sample of diabetic (n = 451) and non-diabetic individuals (n = 451) were matched to on age, gender, ethnicity, and education. The diabetic individuals experienced greater depression on both continuous and ordinal diagnostic variables. Counter to expectation, there was no relationship observed between depression and HbA1c in diabetic individuals, r = .04, p > .05.
Date: December 2010
Creator: Ensign, Jeffrey S.
Partner: UNT Libraries
open access

Depression in Diabetic and Non-Diabetic Individuals: Physical Activity, Nutrition, and Diet

Description: About 8.3% of individuals diagnosed with diabetes mellitus (DM) are diagnosed with comorbid depression, a higher rate than the general adult population. This project examined the differences of depression symptoms experienced between diabetic and matched non-diabetic individuals and the relationship of daily activity and nutrition behaviors with depression between these groups. The 2005-2006 National Health and Nutrition Examination Survey (NHANES) was utilized to assess: depression symptoms, diabetic glycemic control as measured by glycoginated hemoglobin (HbA1c), amount of physical activity, percentage of macronutrients, daily frequencies of foods consumed, and the use of nutritional food labels to make food choices. A sample of diabetic (n = 451) and non-diabetic individuals (n = 451) were matched to on age, gender, ethnicity, and education. The diabetic individuals experienced greater depression on both continuous and ordinal diagnostic variables. Counter to expectation, there was no relationship observed between depression and HbA1c in diabetic individuals, r = .04, p > .05.
Date: December 2010
Creator: Edwards, Kate G.
Partner: UNT Libraries
open access

Demographic and Psychosocial Contributions to the Expression of Schizotypal Personality Traits.

Description: Previous research suggests there are a number of variables that are associated with the expression of schizotypal personality disorder (SPD) symptoms. Such variables include childhood trauma, depression and anxiety, substance use, normal-range personality traits, ethnicity, and gender. However, research to date has not examined all of these variables in a single study to determine how they may be interrelated or differentially related to SPD symptom domains. Of particular interest is the association of these variables as explained by the diathesis-stress model. This study utilized a convenience sample of 298 undergraduate students to examine a continuous range of scores for symptoms of SPD and how the interrelation of biological factors such as gender and ethnicity and psychosocial factors and stressors such as childhood trauma and personality traits, specifically neuroticism and extroversion, influence the expression of SPD symptoms. It was predicted that anxiety, depression, stress, and childhood trauma would positively correlate to SPD symptoms. It was also hypothesized that neuroticism and substance use would positively correlate to schizotypal traits and extroversion would be negatively correlated to schizotypal traits as measured by the Schizotypal Personality Questionnaire-Brief. It was further hypothesized that psychosocial stressors would be moderated by the aforementioned biological factors.
Date: December 2010
Creator: Hernandez, Nikki
Partner: UNT Libraries
open access

Soft Landing Ion Mobility Mass Spectrometry: History, Instrumentation and an Ambient Pressure Application

Description: Preparative mass spectrometry is an important method for the synthesis of new materials. Recently, soft landing mass spectrometry has been used to land ions on surfaces to coat or otherwise alter them. Commercial soft landing instruments do not yet exist, and the physical phenomenon of soft landing has not yet been fully described. For future ion mobility soft landing research, the theory of ion mobility, ion optics and soft landing is discussed, and 2 soft landing instruments have been built and described, along with proof of concept experiments for both instruments. Simulations of the process of ion mobility and ion optics for use in these instruments, as well as some preliminary results for the optics are included. Surfaces described include copper on mica and iron on silicon. Self assembly of soft landed ions is observed on the surfaces. The instruments constructed will be useful for future soft landing research, and soft landing can be used for future materials research with special attention focused on the self-assembly of the landed ions.
Date: December 2010
Creator: Birdwell, David
Partner: UNT Libraries
open access

The Enemy of My Enemy: International Alliances Against Transnational Terrorist Organizations

Description: A dearth of pre-existing research in the field prompted this thesis on whether traditional econometric analyses of war deterrent alliances are applicable to modern alliances for counter terror purposes. Apparent foundational and contextual differences between the two types of alliances and the costs and benefits member nations derive from each lead the author to theorize that factors contributing to the formation of each alliance are fundamentally similar. Multiple types of statistical models are used to measure variables from the Correlates of War and Polity datasets combined with custom variables in a new dataset concerning major transnational terrorist attacks and the resultant alliances in testing the effect of traditionally contributing formation factors on alliances against terrorism. The results indicate that some contributing factors are similar, extant analysis tools have utility and that further investigation is justified.
Date: December 2010
Creator: Berthume, Joshua Guy
Partner: UNT Libraries
open access

Microstructure Evolution in Laser Deposited Nickel-Titanium-Carbon in situ Metal Matrix Composite

Description: Ni/TiC metal matrix composites have been processed using the laser engineered net shaping (LENS) process. As nickel does not form an equilibrium carbide phase, addition of a strong carbide former in the form of titanium reinforces the nickel matrix resulting in a promising hybrid material for both surface engineering as well as high temperature structural applications. Changing the relative amounts of titanium and carbon in the nickel matrix, relatively low volume fraction of refined homogeneously distributed carbide precipitates, formation of in-situ carbide precipitates and the microstructural changes are investigated. The composites have been characterized in detail using x-ray diffraction, scanning electron microscopy (including energy dispersive spectroscopy (XEDS) mapping and electron backscatter diffraction (EBSD)), Auger electron spectroscopy, and transmission (including high resolution) electron microscopy. Both primary and eutectic titanium carbides, observed in this composite, exhibited the fcc-TiC structure (NaCl-type). Details of the orientation relationship between Ni and TiC have been studied using SEM-EBSD and high resolution TEM. The results of micro-hardness and tribology tests indicate that these composites have a relatively high hardness and a steady-state friction coefficient of ~0.5, both of which are improvements in comparison to LENS deposited pure Ni.
Date: December 2010
Creator: Gopagoni, Sundeep
Partner: UNT Libraries
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