UNT Theses and Dissertations - 404 Matching Results

Search Results

Automated Classification of Emotions Using Song Lyrics

Description: This thesis explores the classification of emotions in song lyrics, using automatic approaches applied to a novel corpus of 100 popular songs. I use crowd sourcing via Amazon Mechanical Turk to collect line-level emotions annotations for this collection of song lyrics. I then build classifiers that rely on textual features to automatically identify the presence of one or more of the following six Ekman emotions: anger, disgust, fear, joy, sadness and surprise. I compare different classification systems and evaluate the performance of the automatic systems against the manual annotations. I also introduce a system that uses data collected from the social network Twitter. I use the Twitter API to collect a large corpus of tweets manually labeled by their authors for one of the six emotions of interest. I then compare the classification of emotions obtained when training on data automatically collected from Twitter versus data obtained through crowd sourced annotations.
Date: December 2012
Creator: Schellenberg, Rajitha
Partner: UNT Libraries

Automatic Tagging of Communication Data

Description: Globally distributed software teams are widespread throughout industry. But finding reliable methods that can properly assess a team's activities is a real challenge. Methods such as surveys and manual coding of activities are too time consuming and are often unreliable. Recent advances in information retrieval and linguistics, however, suggest that automated and/or semi-automated text classification algorithms could be an effective way of finding differences in the communication patterns among individuals and groups. Communication among group members is frequent and generates a significant amount of data. Thus having a web-based tool that can automatically analyze the communication patterns among global software teams could lead to a better understanding of group performance. The goal of this thesis, therefore, is to compare automatic and semi-automatic measures of communication and evaluate their effectiveness in classifying different types of group activities that occur within a global software development project. In order to achieve this goal, we developed a web-based component that can be used to help clean and classify communication activities. The component was then used to compare different automated text classification techniques on various group activities to determine their effectiveness in correctly classifying data from a global software development team project.
Date: August 2012
Creator: Hoyt, Matthew Ray
Partner: UNT Libraries

Back in My Hands: The Role of Self-Forgiveness and Stigma in HIV-Positive Adults

Description: While advancements in treatment have made HIV a more manageable disease, only recently have psychosocial variables associated with the health of persons living with HIV (PLH) began to receive increased scrutiny. HIV-related stigma, considered by some researchers to be a “second epidemic,” is one such psychosocial variable and is associated with negative physiological and psychological health outcomes. In an effort to alleviate the effects of stress, increased research attention has focused on forgiveness as a teachable coping strategy. Current forgiveness interventions demonstrate encouraging results in decreasing anger and neutralizing stress but have not been applied to HIV-positive populations. In this study, Lazarus and Folkman’s transactional model of stress and coping (1984) and Prochaska and Velicer’s transtheoretical model of health behavior (1997) were utilized as theoretical frameworks to inform a randomized clinical trial that examines coping skills, particularly forgiveness, in PLH and perceived HIV-related stigma. An ethnically diverse sample of HIV-positive adults (n = 57) was randomized into a treatment or control group. The treatment group participated in six weeks of cognitive-behavioral group therapy that focused on the teaching of forgiveness as an effective coping tool while the control group was psychoeducational in nature and did not involve mention of forgiveness. Data was obtained on a variety of medical and psychosocial variables, including types of forgiveness (dispositional forgiveness, forgiveness of self, forgiveness of others, and forgiveness of situations) and perceived HIV-related stigma. Data were collected at three time points: at baseline (Time 1) prior to randomization of participants to the treatment or control group, immediately post intervention (Time 2), and at six-month follow-up (Time 3). Importantly, forgiveness was shown to be a teachable skill that PLH can use to potentially improve mental health. Men in the treatment group reported significantly higher levels of dispositional forgiveness and self-forgiveness than men in the ...
Date: August 2012
Creator: Hua, William Q.
Partner: UNT Libraries

Baseband Noise Suppression in Ofdm Using Kalman Filter

Description: As the technology is advances the reduced size of hardware gives rise to an additive 1/f baseband noise. This additive 1/f noise is a system noise generated due to miniaturization of hardware and affects the lower frequencies. Though 1/f noise does not show much effect in wide band channels because of its nature to affect only certain frequencies, 1/f noise becomes a prominent in OFDM communication systems where narrow band channels are used. in this thesis, I study the effects of 1/f noise on the OFDM systems and implement algorithms for estimation and suppression of the noise using Kalman filter. Suppression of the noise is achieved by subtracting the estimated noise from the received noise. I show that the performance of the system is considerably improved by applying the 1/f noise suppression.
Date: May 2012
Creator: Rodda, Lasya
Partner: UNT Libraries

Bearing Strength of Cold Formed Steel Bolted Connections in Trusses

Description: The existing design provision in North American Specification for Cold- Formed Steel Structural Member (AISI S100) for the bearing strength of bolted connections were developed from tests on bolted connected sheets which were restrained by bolt nut and head with or without washers. However, in the cold-formed assemblies, particularly in trusses, the single bolt goes through both sides of the connected sections, making the connected sheets on each side unrestrained. the warping of the unrestrained sheet may reduce the bearing strength of the bolted connection. This research investigates the behavior and strength of bearing failure in bolted connections in cold-formed steel trusses. Tensile tests were conducted on trusses connections with various material thicknesses. It was found that the AISI S100 works well for thick connections but provides unconservative predictions for thin materials. Based on the experimental results, a modified bearing strength method is proposed for calculating the bearing strength of bolted truss connections. the proposed method can be used for any cold-formed steel connections with unrestrained sheet.
Date: May 2012
Creator: Panyanouvong, Mark
Partner: UNT Libraries

The Beauty of Nature As a Foundation for Environmental Ethics: China and the West

Description: My dissertation aims at constructing an environmental ethics theory based on environmental aesthetics in order to advocate and promote environmentally sustainable practices, policies, and lifestyles. I attempt to construct an integrated environmental aesthetics in order to inspire people’s feelings of love towards nature and motivate them to protect it. In order to achieve this goal, I first examine the philosophical understanding and aesthetic appreciation of nature from philosophical traditions of China, which have an impact on the general public’s attitude towards nature. in chapter one of my dissertation, I point out that nature is viewed as an organic system which is always in a self-generating process of production and reproduction of life. the metaphysical foundation for this perspective of nature is ch’i. Therefore the aesthetic appreciation of nature in China is also the aesthetic appreciation of ch’i. with regard to the concept of ch’i, I focus on the following three questions: (1) what are the objective and aesthetic features of ch’i? (2) How do the Chinese appreciate aesthetic features of ch’i? (3) Why the objective features of ch’i are regarded as the objects of aesthetic appreciation? I argue that the Chinese appreciate the aesthetic features of ch’i by using intellectual intuition and that empathy is the reason why the objective features of ch’i are considered to be aesthetic features. in Chapter 2, I explain in detail the two aesthetic categories for aesthetic appreciation of nature in two major philosophical schools in China: emptiness and creativity. in Chapter 3, I examine the philosophical foundations for aesthetic appreciation of nature in the West. I first investigate the influence of traditional Western philosophy on the perceptions of nature. I argue that traditional Western philosophical thinking doesn’t support aesthetic appreciation of nature. I point out that aesthetic appreciation of nature started from eighteenth century ...
Date: May 2012
Creator: Gao, Shan
Partner: UNT Libraries

Behavioral Aspects of Latino Familialism: a Three Study Analysis

Description: The existing research on Latino familialism draws a distinction between the attitudes associated with familialism and familialism-based action. Because attitudes tend to be more stable when considering variables such as immigration generation status, etc., social science researchers tend to employ measures based on attitudinal aspects of familialism, rather than action or behavior. Because of this preference, there is a lack of studies that examine familialism-based action and behaviors. This dissertation consists of three unique studies that examine actions and behaviors associated with familialism, while taking into account the methodological concerns expressed by previous researchers. The first study uses nationally representative U.S. data to compare the differences in the frequency of contact with various family members, among black non-Hispanics, Hispanics, and white non-Hispanics. The central finding of this study is that Hispanics maintain more frequent contact with family than white non-Hispanics, but there is no difference between Hispanics and black non-Hispanics, with the exception of contact with fathers. The second study, which employs qualitative data collected from a metropolitan area in the Southwest U.S., examines the locus of educational aspirations and expectations among a sample of Hispanics and white non-Hispanics. Among other things, this study finds that Hispanic females were more likely than other participants to make statements that suggest the aspirations or expectations of significant others were a strong influence in the decision to attend college. This study further argues that this tendency is related to the acquiescent nature of traditional Hispanic gender norms associated with the familial concept of marianismo. Using nationally representative U.S. data, the final study finds that, other things being equal, Hispanic college students are more likely than non-Hispanic students to attend a college or university that is within fifty miles of their permanent residence. The study further finds that this tendency mediates the gap between ...
Date: December 2012
Creator: Comeau, Joseph Adrien
Partner: UNT Libraries

Beta-adrenergic Blockade Via Atenolol and Its Effects on Blood Pressure, Heart Rate, and Renal Morphology in the Developing Chicken Gallus Gallus Domesticus

Description: Chicken embryos were chronically exposed to the ?1- blocker atenolol during one of three stages: mesonephros (E7-E9), mesonephros-metanephros (E11-E13), or metanephros (E15-E17). Mesonephros group hearts were larger than all other groups (P < 0.01). Mesonephros and metanephros group kidneys were larger than all remaining groups (P < 0.0001). The mesonephros group nephron number was ~40% lower than control values (P = 0.002). Glomerular areas were 26% and 18% larger than the control group in the mesonephros and metanephros groups, respectively (P < 0.001). These data suggest an E7-E9 critical window of cardiovascular and renal development for atenolol. Acute atenolol exposure in E15 embryos showed an increase in mean arterial pressure with all but the highest dose. All doses significantly decreased heart rate.
Date: December 2012
Creator: Rossitto Lopez, Josie Jovita
Partner: UNT Libraries

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

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 the Comanche homeland than any Texas post of the period. Its records clearly show that the Army used Fort Bascom as a key forward base of operations against Comanches and Kiowas. An examination of Bascom's post returns, daily patrols, and major expeditions allows its history to provide a useful perspective on the nineteenth-century American Southwest.
Date: August 2012
Creator: Blackshear, James Bailey
Partner: UNT Libraries

Blogging and Tweens: Communication Portal to Reading Selection and Engagement

Description: The ethnographic study utilized the research techniques of observations, content analysis, and semi-structured interviews with tween participants (i.e., 9 through 13 year-old youth) during an 8-week literary blog project. Twenty-six participants created individual blog pages within a member-only classroom blog site that allowed for online communication between members. the blog project incorporated social networking applications with which youth frequently engage. the research questions ensured data regarding what facets participants found appealing and motivating during the project was collected. the questions allowed for determining if participants utilized peer blogs for reading material selection or repurposed the blogs to discuss other topics. Components of self-determination theory and engagement theory underlay the project design and aided in identifying motivational aspects of the data. Frequency tables outlined the identified patterns and structures of participants’ online activity. Participants found the ability to change the colors of their blog backgrounds and to design their individual blogs and the giving and receiving of feedback to be the two most appealing features of the project. Participants chose books from peer suggestions in the online world but also selected materials from recommendations they received in face-to-face interactions with their peers, their teacher, and the school librarian. Little evidence of repurposing the blog for social topics was observed. Participants engaged in discussions predominantly based around the books they were currently reading or had read. Implications for incorporating social networking applications within the classroom environment are discussed.
Date: May 2012
Creator: Sharber, Shelli K.
Partner: UNT Libraries

Blood Brothers

Description: Blood Brothers as a media project works as a diptych. There are two – seemingly identical – pieces of the project that must both be experienced to understand the project as a whole. The first piece of the project is the linear documentary. This part captures the experience as it exists in the past. It exists as a master copy of the original story of mine and my foster brother’s relationship. This version of the story will always exist in the past. The second part is the live-cinema documentary performance. In this version of the story, my foster brother and I are no longer only images on a screen; we are living, breathing, and emotional subjects in the present. Our presence alters how the audience consumes the material.
Date: August 2012
Creator: Quam, Jonathon David
Partner: UNT Libraries

Bodies and Other Firewood

Description: The chakra system consists of seven energetic vortexes ascending up the spine that connect to every aspect of human existence. These vortexes become blocked and unblocked through the course of a life, these openings and closings have physiological and mental repercussions. Knowledge of these physical and mental manifestations, indicate where the chakra practitioner is in need, the practitioner can then manipulate their mind and body to create a desired outcome. These manipulations are based upon physical exercises and associative meditations for the purpose of expanding the human experience. As a poem can be thought of as the articulation of the human experience, and the chakra system can be thought of as a means to understand and enhance that experience, it is interesting and worthwhile leap to explore the how the chakras can develop and refresh the way we read and write poetry. This critical preface closely reads seven poems, one through each chakra, finding what the chakras unveil. Here, each chakra is considered for its dynamic creative capabilities and for its beneficial potentiality in the reading and writing process, finding each chakra provides tools: idea generators with the potential to free the poet from usual patterns of creativity while broadening vision and expressivity. In this collection of poetry poems are experiences chopped into consumable units that show and tell the constant negotiation between what is actually happening and the stories we tell ourselves about what is happening.
Date: December 2012
Creator: Blomgren, Aubree Sky
Partner: UNT Libraries

Body Dissatisfaction, Disordered Eating Behaviors and Body Image Quality of Life in African American Women with Hiv

Description: The purpose of the current study was to further our understanding of the subjective experience of middle-age African American women who are HIV+ and on highly active antiretroviral therapy, particularly how self-reported lipodystrophy (LD), levels of body dissatisfaction, body image quality of life, and engagement in disordered eating behaviors are related. Multiple regression, MANOVA, MANCOVA, ANOVA, and chi-square were utilized to test hypotheses. Results revealed that HIV+ and HIV- women did not differ significantly on their levels of body dissatisfaction or drive for thinness. When HIV+ women were examined in more detail a pattern emerged: women who self-reported fat hypertrophy had significantly higher levels of body dissatisfaction, bingeing, but not purging, and dietary restriction and fear of weight gain compared to women who did not self-report LD. About 75% of the sample was overweight or obese, and when BMI was controlled for, these differences persisted for body dissatisfaction and disordered eating behaviors for fat hypertrophy, but not fat atrophy. Overall, the findings indicate that the type of LD, specifically hypertrophy, is more related to body dissatisfaction and disordered eating behaviors, than LD in general. Clinical implications and limitations of these findings are discussed.
Date: December 2012
Creator: Hammon, Sarah A.
Partner: UNT Libraries

Branded Content: Understanding the Mechanisms of Strategic Messaging in Entertainment Television Formats

Description: Branded content as an advertising tactic is a growing phenomenon that is not widely researched and is generally ambiguous in nature. This study uses qualitative methods to explain how branded content is defined, how it functions, and how it can influence a brand. Case studies of IKEA and Chevrolet were compared alongside four interviews with branded content professionals. the data collected suggests that branded content in structure and substance is varied, however it comprises engagement, the brand, and financial transaction. the data collected also suggested that brands take a variety of stances when controlling content to support their brand, and that branded content generally supports the intangible aspects of a brand, as opposed to product features.
Date: May 2012
Creator: Nicholson, Danielle Marie
Partner: UNT Libraries

Bridging the Gap Between Access and Success: a Study of the Impact of an Access and Success Program on Academic Outcomes of Low-income College Freshmen

Description: In response to the increasing cost of college, colleges and universities are leveraging financial aid and academic support services to implement access and success programs intended to help financially disadvantaged students afford and persist through a baccalaureate degree program. This research is a study of the efficacy of one such program at a large research university in the southwestern region of the United States. The study sample included low-income program participants in four cohorts of freshmen enrolling for the first time in college from fall 2007 (Cohort 1) to fall 2010 (Cohort 4) and a comparison group of almost 400 low-income freshmen who enrolled for the first time in college in fall 2006 (the year prior to program implementation) for a sample total of over 2150 students. Approximately 64% were female, 36 % were males, over 60% were African American and Hispanic, and over 75% were first generation college students. Logistic regression was used to measure probability and odds of their academic success and retention in the first year of college utilizing gender, ethnicity, parental degree attainment, and program participation as the independent variables. The logistic regression models illustrated that participation in the program netted a consistently positive and significant impact on academic success across all cohorts, increasing the odds ratio for academic success no less than three times in favor of program participants vis-à-vis the comparison group. The statistical models illustrated that the program netted a slight positive impact on the odds of retention, particularly for African American students. Therefore, the principle implication that might be drawn from this study is that by strategically leveraging financial aid and academic support services, access and success programs can facilitate higher rates of academic success and retention for financially disadvantaged college students.
Date: May 2012
Creator: Collins, Sarah R.
Partner: UNT Libraries

British Labour Government Policy in Iraq, 1945-1950

Description: Britain during the Labour government's administration took a major step toward developing Iraq primarily due to the decision of Ernest Bevin, the Foreign Minister, to start a new British policy toward the Iraqi regimes that would increase the British influence in the area. This led to Bevin's strategy of depending on guiding the Iraqi regime to make economic and political reforms that would lead to social justice.
Date: December 2012
Creator: Alburaas, Theyab
Partner: UNT Libraries

Broad-band Light Emission From Ion Implanted Silicon Nanocrystals Via Plasmonic and Non-plasmonic Effects for Optoelectronics

Description: Broad band light emission ranging from the ultraviolet (UV) to the near infrared (NIR) has been observed from silicon nanoparticles fabricated using low energy (30-45 keV) metal and non-metal ion implantation with a fluence of 5*1015 ions/cm2 in crystalline Si(100). It is found from a systematic study of the annealing carried out at certain temperatures that the spectral characteristics remains unchanged except for the enhancement of light emission intensity due to annealing. The annealing results in nucleation of metal nanoclusters in the vicinity of Si nanoparticles which enhances the emission intensity. Structural and optical characterization demonstrate that the emission originates from both highly localized defect bound excitons at the Si/Sio2 interface, as well as surface and interface traps associated with the increased surface area of the Si nanocrystals. The emission in the UV is due to interband transitions from localized excitonic states at the interface of Si/SiO2 or from the surface of Si nanocrystals. The radiative efficiency of the UV emission from the Si nanoparticles can be modified by the localized surface plasmon (LSP) interaction induced by the nucleation of silver nanoparticles with controlled annealing of the samples. The UV emission from Si nanoclusters are coupled resonantly to the LSP modes. The non-resonant emission can be enhanced by electrostatic-image charge effects. The emission in the UV (~3.3 eV) region can also be significantly enhanced by electrostatic image charge effects induced by Au nanoparticles. The UV emission from Si nanoclusters, in this case, can be coupled without LSP resonance. The recombination of carriers in Si bound excitons is mediated by transverse optical phonons due to the polarization of the surface bound exciton complex. The low energy side of emission spectrum at low temperature is dominated by 1st and 2nd order phonon replicas. Broad band emission ranging from the UV to the ...
Date: December 2012
Creator: Singh, Akhilesh K.
Partner: UNT Libraries

Burushaski Case Marking, Agreement and Implications: an Analysis of the Hunza Dialect

Description: This thesis was written to explore the structural case patterns of the Burushaski sentence and to examine the different participant coding systems which appear between noun marking and verb agreement. Verb suffixes follow nominative alignment patterns of agreement, while the verb prefix agrees with the affected argument as determined by semantic relations, as opposed to syntactic ones. The agent noun phrase is directly marked when highly active or volitional, suggesting a system of agent marking on the noun phrase and nominative alignment on the verb suffix. Nominative alignment also allows for a less marked presence of passive voice. Burushaski's agent marking is not entirely consistent; however, its nominative alignment is consistent. The conclusion is that Burushaski is not an ergative language at all.
Date: December 2012
Creator: Smith, Alexander
Partner: UNT Libraries

Cardinal Giovanni Battista De Luca: Nepotism in the Seventeenth-century Catholic Church and De Luca's Efforts to Prohibit the Practice

Description: This dissertation examines the role of Cardinal Giovanni Battista de Luca in the reform of nepotism in the seventeenth-century Catholic Church. Popes gave very large amounts of money to their relatives and the burden of nepotism on the Catholic Church was very onerous. The Catholic Church was crippled by nepotism and unable to carry out its traditional functions. Although Cardinal de Luca and Pope Innocent XI worked tirelessly to end nepotism, they were thwarted in their attempts by apprehension among the Cardinals concerning conciliarism and concerning the use of reform measures from the Council of Trent; by Gallicanism and the attempts of the French King to exercise power over the French Church; and by the entrenchment of nepotism and its long acceptance within the Church. Cardinal de Luca and Innocent XI were not able to push through reforms during their lifetimes but Pope Innocent XII was able to complete this reform and pass a reform Bull. This dissertation has two complementary themes. First, a confluence of circumstances allowed for the unfettered growth of nepotism in the seventeenth-century Church to the point of threatening the well-being of the Catholic Church. Reform was not undertaken until the threat to Church finances was severe. Secondly, two upstanding and honest reformers arose in the Catholic Church to correct the problem, de Luca and Innocent XI. The achievements of Cardinal de Luca, also an important reformer of the Canon Law, are almost unknown to an English-speaking audience.
Date: August 2012
Creator: Cowan, H. Lee
Partner: UNT Libraries

Caregiver Perceptions of Wandering Behavior in the Adrd (Alzheimer’s Disease and Related Dementias) Patient

Description: The dissertation examined family caregivers’ perceptions of wandering behavior after their loved one has been diagnosed with ADRD (Alzheimer’s disease and related dementias). Semi-structured in-depth face-to-face interviews of a convenience sample of 22 caregivers in the Dallas metropolitan area were conducted. Responses were analyzed using a grounded theory approach. The use of qualitative methods facilitated the study of how caregivers of a loved one with ADRD understood and explained in their own voice the wandering behavior associated with the disease and how their views of the behavior informed the caregiving process. In particular, this research examined why some caregivers tend to recognize wandering behavior as significant early on while the ADRD patient is still living in the home (and community) and modifications can be made to keep him or her there despite the behavior, and why some caregivers do not. Findings indicated that caregivers were concerned about the general safety of their loved one. Precautions were taken within the home for conditions related to frailty, but were much less likely to be taken to address wandering behavior and its negative consequences. Three groups of caregivers emerged: (a) those who primarily reacted to their loved one’s problem behaviors including wandering, and intervened minimally; (b) those who were proactive, making modifications in their routines and environment to protect their loved one after a trigger event; and (c) those who had a mixed response, who did the best that they could with what they had. This last group of caregivers took on additional roles, modified their homes for safety, but environmental stressors and inadequate supports limited their interventions. Implications of the findings for aging in place and community, further research, policy-making, and practitioners are discussed.
Date: August 2012
Creator: Dickson, Patricia
Partner: UNT Libraries

Challenge the Silence

Description: This collection of personal essays about incest, abuse, and depression explores the lasting effects of an invisible childhood. The essays follow the protagonist from the age of five to her early twenties. Her brother, at a young age, becomes sexually abusive of her and her sisters, and her parents fail to protect their daughters. The family is divided as the older girls strive to defend their little sisters, while their parents attempt to excuse their son. When her brother is finally sent away, the protagonist is left to salvage what remains of her relationships with her parents.
Date: August 2012
Creator: Peterson, Erica
Partner: UNT Libraries

Changes in Gene Expression Levels of the Ecf Sigma Factor Bov1605 Under Ph Shift and Oxidative Stress in the Sheep Pathogen Brucella Ovis

Description: Brucella ovis is a sexually transmitted, facultatively anaerobic, intracellular bacterial pathogen of sheep (Ovis aries) and red deer (Cervus elaphus). Brucella spp. infect primarily by penetrating the mucosa and are phagocytized by host macrophages, where survival and replication occurs. At least in some species, it has been shown that entry into stationary phase is necessary for successful infection. Brucella, like other alphaproteobacteria, lack the canonical stationary phase sigma factor ?s. Research on diverse members of this large phylogenetic group indicate the widespread presence of a conserved four-gene set including an alternative ECF sigma factor, an anti-sigma factor, a response regulator (RR), and a histidine kinase (HK). The first description of the system was made in Methylobacterium extorquens where the RR, named PhyR, was found to regulate the sigma factor activity by sequestering the anti-sigma factor in a process termed "sigma factor mimicry." These systems have been associated with various types of extracellular stress responses in a number of environmental bacteria. I hypothesized that homologous genetic sequences (Bov_1604-1607), which are similarly found among all Brucella species, may regulate survival functions during pathogenesis. To further explore the involvement of this system to conditions analogous to those occurring during infection, pure cultures of B. ovis cells were subjected to environments of pH (5 and 7) for 15, 30, and 45 minutes and oxidative (50mM H2O2) stress, or Spermine NONOate for 60 minutes. RNA was extracted and converted to cDNA andchanges in transcript levels of the sigma factor Bov1605 were measured using qPCR. Preliminary results indicate that under the exposure to Spermine NONOate there was little change in expression, but under oxidative stress expression of the sigma factor Bov1605 was 4.68-fold higher than that expressed under normal conditions. These results suggest that the sigma factor Bov1605 may be involved in oxidative stress defense during ...
Date: December 2012
Creator: Kiehler, Brittany Elaine
Partner: UNT Libraries

Characterization of Arthrobacter Globiformis Aspartate Transcarbamylase Concentrations of Substrates

Description: This thesis consists of one major section with two subsections. The first subsection investigates the activity of Arthrobacter globiformis aspartate transcarbamylase's specific activity with increasing concentrations of the enzyme's substrate. Dihydroorotase (DHOase) activity was also measured with increasing concentrations of the substrate dihydroorotate. The second subsection collected data in order to classify the enzyme, resulting in a classification into the category of class A ATCases with bifunctional ATCase-DHOase complexes. The thesis provides evidence to broaden understanding of the ATCase and DHOase enzymes for members of the family that Arthrobacter belongs to.
Date: December 2012
Creator: Wright, Jackie
Partner: UNT Libraries

Characterization of Ecg Signal Using Programmable System on Chip

Description: Electrocardiography (ECG) monitor is a medical device for recording the electrical activities of the heart using electrodes placed on the body. There are many ECG monitors in the market but it is essential to find the accuracy with which they generate results. Accuracy depends on the processing of the ECG signal which contains several noises and the algorithms used for detecting peaks. Based on these peaks the abnormality in the functioning of the heart can be estimated. Hence this thesis characterizes the ECG signal which helps to detect the abnormalities and determine the accuracy of the system.
Date: December 2012
Creator: Ravuru, Anusha
Partner: UNT Libraries