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Endocannabinoid System in a Planarian Model (open access)

Endocannabinoid System in a Planarian Model

In this study, the presence and possible function of endocannabinoid ligands in the planarian is investigated. The endocannabinoids ananadamide (AEA) and 2-arachidonoylglycerol (2-AG) and entourage NAE compounds palmitoylethanolamide (PEA), stearoylethanolamide (SEA) and oleoylethanolamide (OEA) were found in Dugesia dorotocephala. Changes in SEA, PEA, and AEA levels were observed over the initial twelve hours of active regeneration. Exogenously applied AEA, 2-AG and their catabolic inhibition effected biphasic changes in locomotor velocity, analogous to those observed in murines. The genome of a close relative, Schmidtea mediterranea, courtesy of the University of Utah S. med genome database, was explored for cannabinoid receptors, none were found. A putative fatty acid amide hydrolase (FAAH) homolog was found in Schmidtea mediterranea.
Date: December 2010
Creator: Mustonen, Katie Lynn
Object Type: Thesis or Dissertation
System: The UNT Digital Library
User Acceptance of North Central Texas Fusion Center System by Law Enforcement Officers (open access)

User Acceptance of North Central Texas Fusion Center System by Law Enforcement Officers

The September 11 terrorist attacks pointed out the lack of information sharing between law enforcement agencies as a potential threat to sound law enforcement in the United States. Therefore, many law enforcement agencies as well as the federal government have been initiating information sharing systems among law enforcement agencies to eradicate the information sharing problem. One of the systems established by Homeland Security is the North Central Texas Fusion Center (NCTFC). This study evaluates the NCTFC by utilizing user acceptance methodology. The unified theory of acceptance and the use of technology is used as a theoretical framework for this study. Within the study, user acceptance literature is examined and various models and theories are discussed. Furthermore, a brief information regarding the intelligence work done by law enforcement agencies are explained. In addition to the NCTFC, several major law enforcement information systems are introduced. The data for this study comes from the users of the NCTFC across the north central Texas region. Surveys and interviews are used to triangulate data. It is found in this study that performance expectancy and effort expectancy are important indicators of system use. Furthermore, outreach and needs assessment are important factors in establishing systems. The results …
Date: December 2010
Creator: Odabasi, Mehmet
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Effects of Plasma, Temperature and Chemical Reactions on Porous Low Dielectric Films for Semiconductor Devices (open access)

Effects of Plasma, Temperature and Chemical Reactions on Porous Low Dielectric Films for Semiconductor Devices

Low-dielectric (k) films are one of the performance drivers for continued scaling of integrated circuit devices. These films are needed in microelectronic device interconnects to lower power consumption and minimize cross talk between metal lines that "interconnect" transistors. Low-k materials currently in production for the 45 and 65 nm node are most often organosilicate glasses (OSG) with dielectric constants near 2.8 and nominal porosities of 8-10%. The next generation of low-k materials will require k values 2.6 and below for the 45 nm device generation and beyond. The continuous decrease in device dimensions in ultra large scale integrated (ULSI) circuits have brought about the replacement of the silicon dioxide interconnect dielectric (ILD), which has a dielectric constant (k) of approximately 4.1, with low dielectric constant materials. Lowering the dielectric constant reduces the propagation delays, RC constant (R = the resistance of the metal lines; C = the line capacitance), and metal cross-talk between wires. In order to reduce the RC constants, a number of low-k materials have been studied for use as intermetal dielectrics. The k values of these dielectric materials can be lowered by replacing oxide films with carbon-based polymer films, incorporating hydrocarbon functional groups into oxide films (SiOCH …
Date: December 2010
Creator: Osei-Yiadom, Eric
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Effects of Copying Before, Copying After, and Guessing on Acquisition Rate and Retention (open access)

The Effects of Copying Before, Copying After, and Guessing on Acquisition Rate and Retention

Computer-based instructional programs are being used more frequently in classrooms. While these programs offer many benefits from traditional teaching methods, humans still need to program them. There is inconsistency in the literature regarding the best way to design such programs. The purpose of this study was to evaluate the effects of three training procedures in teaching individuals to type a specified three-letter response in the presence of a corresponding symbol. Results show that the training format that prompted individuals to copy the correct response before the opportunity to respond was more efficient than viewing the correct response after an error, or copying the correct response after an error. A discussion of the results as well as implications for classroom use is also provided.
Date: December 2010
Creator: Pinkelman, Sarah Ellen
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Spatial Analysis of North Central Texas Traffic Fatalities 2001-2006 (open access)

Spatial Analysis of North Central Texas Traffic Fatalities 2001-2006

A traditional two dimensional (planar) statistical analysis was used to identify the clustering types of North Central Texas traffic fatalities occurring in 2001-2006. Over 3,700 crash locations clustered in ways that were unlike other researched regions. A two dimensional (x and y coordinates) space was manipulated to mimic a one dimensional network to identify the tightest clustering of fatalities in the nearly 400,000 crashes reported from state agencies from 2003-2006. The roadway design was found to significantly affect crash location. A one dimensional (linear) network analysis was then used to measure the statistically significant clustering of flow variables of after dark crashes and daylight crashes. Flow variables were determined to significantly affect crash location after dark. The linear and planar results were compared and the one dimensional, linear analysis was found to be more accurate because it did not over detect the clustering of events on a network.
Date: December 2010
Creator: Rafferty, Paula S.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Effect of Polyphosphoric Acid on Aging Characteristics of PG 64-22 Asphalt Binder (open access)

Effect of Polyphosphoric Acid on Aging Characteristics of PG 64-22 Asphalt Binder

This research presents the results on an experimental investigation to identify the effect of polyphosphoric acid (PPA) on aging characteristics of an asphalt binder. Addition of PPA to asphalt binders is said to improve performance of flexible pavements. Asphalt binder PG 64-22 in modified and unmodified conditions was subjected to aging in the laboratory using a regular oven and also simulated short term aging using rolling thin film oven (RTFO) test. Aging experiments were conducted to analyze the extent of oxidation in terms of changes in molecular structure of the asphalt binder. These changes were appraised using Fourier transform infrared (FTIR) spectroscopy, dynamic shear rheometer (DSR), and epifluorescence microscopy tests. FTIR was used to determine the changes in major bands with addition of PPA. Stiffness and viscoelastic behaviors of asphalts were determined from the DSR test. The stiffness is measured by calculating the shear modulus, G* and the viscoelastic behavior is measured by calculating the phase angle, sin δ. Epifluorescence microscopy is a tool used to study properties of organic or inorganic substances. The morphological characteristics of PPA modified asphalt samples were observed through epifluorescence microscopy. Epifluorescence microscopy reveals the polymer phase distribution in the asphalt binders. Results of this …
Date: December 2010
Creator: Ramasamy, Naresh Baboo
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Determination of Bioconcentration Potential of Selected Pharmaceuticals in Fathead Minnow, Pimephales promelas, and Channel Catfish, Ictalurus punctatus (open access)

Determination of Bioconcentration Potential of Selected Pharmaceuticals in Fathead Minnow, Pimephales promelas, and Channel Catfish, Ictalurus punctatus

The primary objective of this work was to determine the tissue-specific bioconcentration factors (BCFs) of the selected pharmaceuticals: norethindrone (NET), ibuprofen (IBU), verapamil (VER), clozapine (CLZ) and fenofibrate (FFB) in two freshwater fishes: fathead minnow and channel catfish. BCF tests on fathead followed the standard OECD 42-day test while a 14-day abridged test design was used in catfish exposures. Additional objectives included a) comparing the measured BCFs to the US EPA's BCFWIN model predicted values, b) comparing the BCF results from the standard and reduced tests, and c) prediction of chronic risk of the pharmaceuticals in fish using the human therapeutic plasma concentrations. Each test included uptake and depuration phases to measure tissue-specific kinetic BCFs. The results indicated that all the pharmaceuticals, except IBU, have the potential for accumulation in fish. Estimated BCFs for NET, VER and FFB may not be significant in view of the current regulatory trigger level (BCF ≥ 2000); however, CLZ's BCF in the liver had approached the criterion level. Significant differences were noticed in the tissue-specific uptake levels of the pharmaceuticals with the following general trend: (liver/kidney) > (gill/brain) > (heart/muscle) > plasma. IBU uptake was highest in the plasma. When compared to the measured …
Date: December 2010
Creator: Nallani, Gopinath C.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Growth, Structure and Tribological Properties of Atomic Layer Deposited Lubricious Oxide Nanolaminates (open access)

Growth, Structure and Tribological Properties of Atomic Layer Deposited Lubricious Oxide Nanolaminates

Friction and wear mitigation is typically accomplished by introducing a shear accommodating layer (e.g., a thin film of liquid) between surfaces in sliding and/or rolling contacts. When the operating conditions are beyond the liquid realm, attention turns to solid coatings. Solid lubricants have been widely used in governmental and industrial applications for mitigation of wear and friction (tribological properties). Conventional examples of solid lubricants are MoS2, WS2, h-BN, and graphite; however, these and some others mostly perform best only for a limited range of operating conditions, e.g. ambient air versus dry nitrogen and room temperature versus high temperatures. Conversely, lubricious oxides have been studied lately as good potential candidates for solid lubricants because they are thermodynamically stable and environmentally robust. Oxide surfaces are generally inert and typically do not form strong adhesive bonds like metals/alloys in tribological contacts. Typical of these oxides is ZnO. The interest in ZnO is due to its potential for utility in a variety of applications. To this end, nanolaminates of ZnO, Al2O3, ZrO2 thin films have been deposited at varying sequences and thicknesses on silicon substrates and high temperature (M50) bearing steels by atomic layer deposition (ALD). The top lubricious, nanocrystalline ZnO layer was structurally-engineered …
Date: December 2010
Creator: Mensah, Benedict Anyamesem
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Impact of Genetics, Socioeconomic Status, and Lifestyle Factors on Visual Health in an Adult Population (open access)

The Impact of Genetics, Socioeconomic Status, and Lifestyle Factors on Visual Health in an Adult Population

The purpose of this dissertation was to understand how genetics, socioeconomic status (SES), and lifestyle factors influence the development of age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy in an adult population in Dallas County. Two hundred fifty-three older adults participated in this study as the sample. Crosstabulation and binary logistic regression were utilized to analyze the data. Results indicated a disparity among participants' test scores, visual health status, and perceptions of their visual impairment and highlighted the fact that many seniors are not educated about age-related retinal disorders. Furthermore, variables reaching statistical significance were consistent with the literature included race/ethnicity, age, having a family history of both AMD and diabetes, frequency of eye exams, and level of education. The results not consistent with the literature as affecting visual health included health insurance, access to health care, body weight, and smoking status. Recommendations for future study included applied research focusing on determining risk factors, raising awareness, educating, and providing early detection of these diseases among low to middle income Caucasian, African American, and Hispanic older adults.
Date: December 2010
Creator: Mitzel, Gina Marie
Object Type: Thesis or Dissertation
System: The UNT Digital Library
End of Life Care:  African Americans' Disproportionate Use of Hospice (open access)

End of Life Care: African Americans' Disproportionate Use of Hospice

The United States of America is a country composed of various ethnicities. This country is considered to be a multi-cultural society. There are various cultural traditions values, norms and superstitious practices within each ethnic group. Attitudes toward end of life care are complex and vary differently across each ethnic group. This study explored factors that explained African Americans' disproportionate use of hospice. Access to hospice care was address, experience with hospice was explored, and recommendations were provided. This study conducted non-experimental research. The design of this exploratory study was quantitative in nature. A survey approach was utilized to collect data that was statistically analyzed. The important concept was African American disproportionate use of hospice. The variable willingness to use was employed to try to explain African Americans' disproportionate use of hospice. The independent variables African Americans who mistrust formal healthcare providers and knowledge about hospice services were operationalized using multiple indicators. The independent variable experience with hospice services did not use a scale. The research findings supported all three study hypotheses. This research results recommend that an important focus of the future be to counsel persons on the availability of hospice as an option for end-of-life care. Well-structured programs of …
Date: December 2010
Creator: McDonald, Ray
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Eating from the Tree of Knowledge: The Impact of Visual Culture on the Perception and Construction of Ethnic, Sexual, and Gender Identity (open access)

Eating from the Tree of Knowledge: The Impact of Visual Culture on the Perception and Construction of Ethnic, Sexual, and Gender Identity

This study explores the way that visual culture and identity creates understanding about how the women in my family interact and teach each other. In the study issues of identity, liminality, border culture, are explored. The study examines how underrepresented groups, such as those represented by Latinas, can enter into and add to the discourses of art education because the women who participated have learned to maneuver through the world, passing what they have learned to one another, from one generation to the next. Furthermore, the study investigates ways in which visual cues offer a way for the women in my family to negotiate their identity. In the study the women see themselves in signs, magazines, television, dolls, clothing patterns, advertisements, and use these to find ways in which to negotiate the borderlands of the places in which they live. Although the education that occurred was informal, its importance is in creating a portal through which to self reflect on the cultural work of educating.
Date: December 2010
Creator: Peralta, Andrés
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Quantitative Analysis of the Relationship of a Non-traditional New Student Orientation in an Urban Community College with Student Retention and Grade Point Average Among Ethnic Groups (open access)

A Quantitative Analysis of the Relationship of a Non-traditional New Student Orientation in an Urban Community College with Student Retention and Grade Point Average Among Ethnic Groups

This quantitative study examined relationships of attending a new student orientation program related to student retention and academic success. A research group of 464 students of Tarrant County College Northwest, a community college campus in Fort Worth, Texas, who voluntarily attended a 2-hour pre-semester new student orientation program was compared to a group of 464 students on the same campus who did not attend the program. Comparisons were made with regard to retention and GPA. Ethnic ratios of both groups are 4% Black, 26% Hispanic, 66% White, and 4% other ethnicities. Chi square data analysis was utilized to determine if statistically significant differences relating to student retention existed between the groups. The independent t-test was used to compare means of calculated GPAs between groups. A one-way ANOVA was used to compare the means of GPAs for ethnic sub-groups. The total group and the Black sub-group showed statistically significant higher levels of second-semester retention (total group p = .018; Black sub-group p = .008) and higher calculated GPAs (total group p = .016; Black sub-group p = .019). No statistically significant results were found among Hispanic students.
Date: December 2010
Creator: Martinez, Vesta Wheatley
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Relationship of Service-Learning and Campus Involvement: A Multivariate Look at the Profile of Today's College Student (open access)

The Relationship of Service-Learning and Campus Involvement: A Multivariate Look at the Profile of Today's College Student

Service-learning continues to gain in popularity across the higher education landscape and can be found in most educational institutions. Although more often found in student affairs programming, it is also viewed as a viable pedagogy. Most studies show that service-learning impacts students in various ways: academically, socially and vocationally. The research study employed quantitative methods. It analyzed prediction of participation in community service/service-learning with students' self-assessment on five outcomes: academic skills, social integration, community integration/alumni expectations, connection with the campus community and change in opinions, values and attitudes. A canonical correlation analysis was conducted on data collected on the Profile of Today's College Student administered by NASPA-Student Affairs Administrators in Higher Education. The data represent a random sample (N = 374) of undergraduate students enrolled at a mid-sized, private four-year university located in the south central United States. The study looked for statistical significance as well as employed effect size measures. The study found participation in community service/service-learning predicts on all five factors in the model. Additional analysis incorporated effect size measures to further strengthen the results. The results were both statistically (p < .001) and practically significant (Rc2 = .101). Connection with the campus community and social integration were …
Date: December 2010
Creator: Kittle, Kris J.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Neuropsychological Functioning in Active Duty Soldiers with Physical and/or Psychological Trauma (open access)

Neuropsychological Functioning in Active Duty Soldiers with Physical and/or Psychological Trauma

This quasi-experimental study investigates neuropsychological functioning differences between 63 active duty soldiers who were placed into three groups (MTBI, PTSD, control) to provide better information for differentiating PTSD and MTBI. The ANAM and MicroCog were utilized to measure psychomotor speed, memory, and attention. Participants with PTSD performed worse on most measures of psychomotor speed and attention, and endorsed more symptoms of depression and anxiety when compared to MTBI and control participants. Further, attention appears to be the best cognitive domain for differentiating PTSD from MTBI, whereas memory variables did not differentiate these groups. Clinical and research implications of these findings are discussed.
Date: December 2010
Creator: Klein, Robert S.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Evaluation of the Developmental Effects and Bioaccumulation Potential of Triclosan and Triclocarban Using the South African Clawed Frog, Xenopus Laevis (open access)

Evaluation of the Developmental Effects and Bioaccumulation Potential of Triclosan and Triclocarban Using the South African Clawed Frog, Xenopus Laevis

Triclosan (TCS) and triclocarban (TCC) are antimicrobials found in U.S. surface waters. This dissertation assessed the effects of TCS and TCC on early development and investigated their potential to bioaccumulate using Xenopus laevis as a model. The effects of TCS on metamorphosis were also investigated. For 0-week tadpoles, LC50 values for TCS and TCC were 0.87 mg/L and 4.22 mg/L, respectively, and both compounds caused a significant stunting of growth. For 4-week tadpoles, the LC50 values for TCS and TCC were 0.22 mg/L and 0.066 mg/L; and for 8-week tadpoles, the LC50 values were 0.46 mg/L and 0.13 mg/L. Both compounds accumulated in Xenopus. For TCS, wet weight bioaccumulation factors (BAFs) for 0-, 4- and 8-week old tadpoles were 23.6x, 1350x and 143x, respectively. Lipid weight BAFs were 83.5x, 19792x and 8548x. For TCC, wet weight BAFs for 0-, 4- and 8-week old tadpoles were 23.4x, 1156x and 1310x. Lipid weight BAFs were 101x, 8639x and 20942x. For the time-to-metamorphosis study, TCS showed an increase in weight and snout-vent length in all treatments. Exposed tadpoles metamorphosed approximately 10 days sooner than control tadpoles. For the hind limb study, although there was no difference in weight, snout-vent length, or hind limb …
Date: December 2010
Creator: King, Marie Kumsher
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Correlates of Video Game Addiction (open access)

Correlates of Video Game Addiction

Video game addiction often leads to a tremendous burden on those afflicted with the condition, draining their time, resources, and life away until they have nothing left. To further elucidate the problem of video game addiction, the current research examines the level of video game addiction of 111 participants, along with their motivation for their addictive behaviors, the quality of life of addicted individuals, and possible relations between video game addiction and other forms of addiction. Results of the current research indicate a correlation between addictive video game use and depression, alcohol use, a desire for escapism, a need for social interaction, and lack of self-control. The results of a multiple regression indicate that, amongst the various research factors, depression is the factor with the most significant link to addictive video game use, implying a dangerous correlation between mental health and an addictive behavior that some erroneously disqualify as a true addiction.
Date: December 2010
Creator: Langley, Alex
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Hierarchical Regression Analysis of the Relationship Between Blog Reading, Online Political Activity, and Voting During the 2008 Presidential Campaign (open access)

A Hierarchical Regression Analysis of the Relationship Between Blog Reading, Online Political Activity, and Voting During the 2008 Presidential Campaign

The advent of the Internet has increased access to information and impacted many aspects of life, including politics. The present study utilized Pew Internet & American Life survey data from the November 2008 presidential election time period to investigate the degree to which political blog reading predicted online political discussion, online political participation, whether or not a person voted, and voting choice, over and above the predication that could be explained by demographic measures of age, education level, gender, income, marital status, race/ethnicity, and region. Ordinary least squares hierarchical regression revealed that political blog reading was positively and statistically significantly related to online political discussion and online political participation. Hierarchical logistic regression analysis indicated that the odds of a political blog reader voting were 1.98 the odds of a nonreader voting, but vote choice was not predicted by reading political blogs. These results are interpreted within the uses and gratifications framework and the understanding that blogs add an interpersonal communication aspect to a mass medium. As more people use blogs and the nature of the blog-reading audience shifts, continuing to track and describe the blog audience with valid measures will be important for researchers and practitioners alike. Subsequent potential effects …
Date: December 2010
Creator: Lewis, Mitzi
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Functional Characterization of Plant Fatty Acid Amide Hydrolases (open access)

Functional Characterization of Plant Fatty Acid Amide Hydrolases

Fatty acid amide hydrolase (FAAH) terminates the endocannabinoid signaling pathway that regulates numerous neurobehavioral processes in animals by hydrolyzing a class of lipid mediators, N-acylethanolamines (NAEs). Recent identification of an Arabidopsis FAAH homologue (AtFAAH) and several studies, especially those using AtFAAH overexpressing and knock-out lines suggest that a FAAH-mediated pathway exists in plants for the metabolism of endogenous NAEs. Here, I provide evidence to support this concept by identifying candidate FAAH cDNA sequences in diverse plant species. NAE amidohydrolase assays confirmed that several of the proteins encoded by these cDNAs indeed catalyzed the hydrolysis of NAEs in vitro. Kinetic parameters, inhibition properties, and substrate specificities of the plant FAAH enzymes were very similar to those of mammalian FAAH. Five amino acid residues determined to be important for catalysis by rat FAAH were absolutely conserved within the plant FAAH sequences. Site-directed mutation of each of the five putative catalytic residues in AtFAAH abolished its hydrolytic activity when expressed in Escherichia coli. Contrary to overexpression of native AtFAAH in Arabidopsis that results in enhanced seedling growth, and in seedlings that were insensitive to exogenous NAE, overexpression of the inactive AtFAAH mutants showed no growth enhancement and no NAE tolerance. However, both active …
Date: December 2010
Creator: Kim, Sang-Chul
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Preschool Mathematics: An Examination of One Program's Alignment with Recommendations from NAEYC and NCTM (open access)

Preschool Mathematics: An Examination of One Program's Alignment with Recommendations from NAEYC and NCTM

The purpose of this study was to determine the extent to which a preschool program followed the recommendations outlined by the National Association for the Education of Young Children (NAEYC) and the National Council of Teachers of Mathematics (NCTM) in their joint position statement "Early Childhood Mathematics: Promoting Good Beginnings." Six teachers were randomly selected from three of the preschool program's six locations that are situated in an urban city in North Texas. Two parts of this program's approach to mathematics were investigated: the teachers' instructional practices and the program's curricular materials. Data came from observations using the Classroom Observation of Early Mathematics-Environment and Teaching (COEMET) protocol and field notes. Each teacher participated in three interviews over the course of this research. Analyses of these sources provided insights into teachers' instructional practices for mathematics. Reviews of curricular documents and lesson plans for mathematics instruction provided information pertaining to the math curriculum used at this preschool program. All of these data sources were analyzed using the framework presented in NAEYC and NCTM's position statement. Analysis of the data indicated that, although teachers did not have any knowledge of these guidelines, teachers followed some of these recommendations; such as presenting children with …
Date: December 2010
Creator: Johnston, Elisabeth
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Self-Efficacy and Fears of Pain and Injury in Gymnastics and Tumbling: Does a Previous Injury Matter? (open access)

Self-Efficacy and Fears of Pain and Injury in Gymnastics and Tumbling: Does a Previous Injury Matter?

The purpose of this study was to explore whether a previous gymnastic or tumbling injury influences gymnasts' and tumblers' self-efficacy, motivation, competition anxiety, and fears of pain and injury. Participants (N = 105) completed survey packets during practice which contained demographic questions and questionnaires that measure self-efficacy for physical abilities and exercise, self-motivation, risk of injury, pain catastrophizing, and sport anxiety. Results of a one-way ANOVA indicated that gymnasts and tumblers who experienced a previous injury were significantly different than those who had not experienced an injury on their self-efficacy for physical abilities (p = .007), self-motivation (p = .007), and perceived risk of reinjury (p = .018). Specifically, these findings indicate that gymnasts and tumblers with previous injuries experience higher levels of self-efficacy for physical abilities, self-motivation, and perceived risk of reinjury. Implications for coaches, gymnasts, and tumblers include: creating an open and comfortable environment to discuss pain and injury, developing strategies to break the negative cycle of fear of injury, and fostering a positive rehabilitation process. In the future, researchers should examine the influence that gender and type of competition has on self-efficacy, self-motivation, perceived risk of reinjury, pain perceptions, and competition anxiety of those who have experienced …
Date: December 2010
Creator: Jackson, Stacy
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Influence of Social Network Graph Structure on Disease Dynamics in a Simulated Environment (open access)

The Influence of Social Network Graph Structure on Disease Dynamics in a Simulated Environment

The fight against epidemics/pandemics is one of man versus nature. Technological advances have not only improved existing methods for monitoring and controlling disease outbreaks, but have also provided new means for investigation, such as through modeling and simulation. This dissertation explores the relationship between social structure and disease dynamics. Social structures are modeled as graphs, and outbreaks are simulated based on a well-recognized standard, the susceptible-infectious-removed (SIR) paradigm. Two independent, but related, studies are presented. The first involves measuring the severity of outbreaks as social network parameters are altered. The second study investigates the efficacy of various vaccination policies based on social structure. Three disease-related centrality measures are introduced, contact, transmission, and spread centrality, which are related to previously established centrality measures degree, betweenness, and closeness, respectively. The results of experiments presented in this dissertation indicate that reducing the neighborhood size along with outside-of-neighborhood contacts diminishes the severity of disease outbreaks. Vaccination strategies can effectively reduce these parameters. Additionally, vaccination policies that target individuals with high centrality are generally shown to be slightly more effective than a random vaccination policy. These results combined with past and future studies will assist public health officials in their effort to minimize the effects …
Date: December 2010
Creator: Johnson, Tina V.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Combining of Korean Traditional Performance and Recent German Techniques in Isang Yun's Kontraste: Zwei Stücke für Violine Solo (1987) (open access)

Combining of Korean Traditional Performance and Recent German Techniques in Isang Yun's Kontraste: Zwei Stücke für Violine Solo (1987)

Isang Yun (1917-1995) embraced a masterful combination of two elements derived from his life: his Korean cultural upbringing and Western musical traditions. This dissertation explores Yun's distinctive style through an analysis of his Kontraste: Zwei Stücke für Violine Solo. Following the introduction (Chapter 1), Chapter 2 contains a brief biography of Isang Yun, and explores the compositions of his Korean period (1917-1955) and his European period (1956-1995). It also discusses how Yun's musical styles changed during these two periods as a result of important life events and due to cultural and political influences. Chapter 3 examines Korean instruments such as Kayakem, Hae-Kem, and Pak; discusses Nonghyun (traditional string techniques of ornamentation in Korean music); and introduces Korean performance techniques. This chapter also provides explanations of these concepts, illustrated through various examples. A subsequent discussion illuminates Yin-Yang theory and Jeong-Jung-Dong, both elements of Taoist philosophy that influenced Yun's compositional style. This is followed by explanations of Hauptton and Umspielung, two compositional techniques that Yun developed and employed in Kontraste. Yun created the idea of Hauptton to reflect the Korean traditional concept of a single note. He used the term Umspielung ("playing around" in German) to describe his interpretation of the four …
Date: December 2010
Creator: Kim, Hyo Jung
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Multiple Activities of Aspartate Transcarbamoylase in Burkholderia cepacia: Requirement for an Active Dihydroorotase for Assembly into the Dodecameric Holoenzyme (open access)

Multiple Activities of Aspartate Transcarbamoylase in Burkholderia cepacia: Requirement for an Active Dihydroorotase for Assembly into the Dodecameric Holoenzyme

The aspartate transcarbamoylase (ATCase) was purified from Burkholderia cepacia 25416. In the course of purification, three different ATCase activities appeared namely dodecameric 550 kDa holoenzyme, and two trimeric ATCases of 140 kDa (consists of 47 kDa PyrB subunits) and 120 kDa (consists of 40 kDa PyrB subunits) each. The 120 kDa PyrB polypeptide arose by specific cleavage of the PyrB polypeptide between Ser74 and Val75 creating an active polypeptide short by 74 amino acids. Both the 40 and 47 kDa polypeptides produced active trimers. To compare the enzyme activity of these trimers, an effector assay using nucleotides was performed. The 140 kDa trimer showed inhibition while the 120 kDa polypeptide showed less inhibition. To verify the composition of the pyrBC holoenzyme complex, B. cepacia dihydroorotase (DHOase, subunit size of 45 kDa) was purified by the pMAL protein fusion and purification system and holoenzyme reconstruction was performed using purified ATCase and DHOase. Both the 140 kDa and the 120 kDa trimers could produce holoenzymes of 550 kDa and 510 kDa, respectively. The reconstructed ATCase holoenzyme from cleaved ATCase showed better reconstruction compared to that from uncleaved ATCase in the conventional ATCase activity gel assay. To characterize the relationship between pyrimidine pathway …
Date: December 2010
Creator: Kim, Hyunju
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Domestic Violence Shelters in Texas: Responding to Programming Needs of Older Victims of Intimate Partner Violence (open access)

Domestic Violence Shelters in Texas: Responding to Programming Needs of Older Victims of Intimate Partner Violence

This study examined if domestic violence shelters in Texas are responding to the needs of older female victims of intimate partner violence. Data for this study was collected through online questionnaire surveys of 45% of Texas domestic violence shelters. Findings of this study indicated that less than 10% of Texas shelters are providing specialized programming for older victims of IPV. In Texas, the demographic growth of older adults has remained comparable to increased national trends. The state of Texas will face several policy implications and social issues related to an older population that is rapidly growing. This includes, the importance of addressing certain members of an aging population who continue to fall victim to domestic violence. Furthermore, an unchanged resource of safety for victims of IPV is domestic violence shelters. Therefore, this study challenges current domestic violence shelter policies to address this issue of a rapidly growing segment of the Texas population. This study found less than 10% of shelters in Texas, who participated in this study, were providing specialized programming and outreach for older victims. Important practical implications for domestic violence shelter programming in Texas is provided.
Date: December 2010
Creator: Lozano, Yvonne M.
Object Type: Thesis or Dissertation
System: The UNT Digital Library