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 Collection: UNT Theses and Dissertations
A 018μm Cmos Transmitter for Ecg Signals
Electrocardiography (ECG) signal transmitter is the device used to transmit the electrical signals of the heart to the remote machine. These electrical signals are ECG signals caused due to electrical activities in the heart. ECG signals have very low amplitude and frequency; hence amplification of the signals is needed to strengthen the signal. Conversion of the amplified signal into digital information and transmitting that information without losing any data is the key. This information is further used in monitoring the heart. digital.library.unt.edu/ark:/67531/metadc407805/
3GPP Long Term Evolution LTE Scheduling
Future generation cellular networks are expected to deliver an omnipresent broadband access network for an endlessly increasing number of subscribers. Long term Evolution (LTE) represents a significant milestone towards wireless networks known as 4G cellular networks. A key feature of LTE is the implementation of enhanced Radio Resource Management (RRM) mechanism to improve the system performance. The structure of LTE networks was simplified by diminishing the number of the nodes of the core network. Also, the design of the radio protocol architecture is quite unique. In order to achieve high data rate in LTE, 3rd Generation Partnership Project (3GPP) has selected Orthogonal Frequency Division Multiplexing (OFDM) as an appropriate scheme in terms of downlinks. However, the proper scheme for an uplink is the Single-Carrier Frequency Domain Multiple Access due to the peak-to-average-power-ratio (PAPR) constraint. LTE packet scheduling plays a primary role as part of RRM to improve the system’s data rate as well as supporting various QoS requirements of mobile services. The major function of the LTE packet scheduler is to assign Physical Resource Blocks (PRBs) to mobile User Equipment (UE). In our work, we formed a proposed packet scheduler algorithm. The proposed scheduler algorithm acts based on the number of UEs attached to the eNodeB. To evaluate the proposed scheduler algorithm, we assumed two different scenarios based on a number of UEs. When the number of UE is lower than the number of PRBs, the UEs with highest Channel Quality Indicator (CQI) will be assigned PRBs. Otherwise, the scheduler will assign PRBs based on a given proportional fairness metric. The eNodeB’s throughput is increased when the proposed algorithm was implemented. digital.library.unt.edu/ark:/67531/metadc490046/
The Academic and Athletic Experiences of African-american Males in a Division I (Fbs) Football Program
This study investigated the academic and athletic experiences of African-American males in a Division I football bowl subdivision football program. Critical race theory, identity development model, and social learning model were the theoretical frameworks used as the critical lenses in a qualitative design to examine the participants. The participants’ responses were analyzed and interpreted using thematic analysis. A qualitative research design, which included individual interviews with 10 second year African-American male football players, was used to address this research problem. The goal was to bring together both the psychological and sociological perspectives and to challenge participants to candidly describe their academic and athletic experiences and attitudes toward obtaining an undergraduate degree. Four themes were determined in the data analysis: differential treatment and determining oneself, time management, relationships, and career aspirations. In relation to the theoretical frameworks, the development of self-confidence and knowledge of balancing their academic and athletic schedules was critical for all participants. The sense of feeling different and challenged because of the differences in culture and experience was evident. From this study, university and collegiate athletics administrators may better understand the backgrounds, challenges, and learning needs of this population. As a result, higher education personnel may improve the services they provide these young men in hopes of educating and developing whole persons—physically, emotionally, intellectually, socially, and spiritually—to become well-rounded and functional in contemporary society. digital.library.unt.edu/ark:/67531/metadc407844/
The Acute Hormonal Response to the Kettlebell Swing Exercise
The purpose of this investigation was to examine the acute hormonal response to a bout of kettlebell swing exercise. Ten healthy men (19-30 y, 23.6 ± 3.5 y, 174.6 ± 5.7 cm, 78.7 ± 9.9 kg) who were engaged in resistance training at least twice per week but were inexperienced with kettlebell swings participated in this study. Participants were familiarized with the kettlebell swing exercise during an initial visit. During the subsequent experimental protocol visit, participants performed 12 rounds of 30 seconds of 16-kg kettlebell swings alternated with 30 seconds of rest. Heart rate (HR) and rating of perceived exertion (RPE) were measured at the end of every round of swings. Fasted blood samples were collected pre-exercise (PRE), immediately post (IP), 15 minutes post (P15), and 30 minutes post exercise (P30) and analyzed for total testosterone (T), growth hormone (GH), cortisol, and lactate concentrations. Participants completed a total of 227 ± 23 swings (average swings per round: 19 ± 2). HR and RPE increased significantly (P < 0.05) throughout the exercise protocol. Lactate concentrations were significantly increased at all post exercise time points compared to PRE. T was significantly increased at IP compared to PRE. GH was significantly increased at IP, P15, and P30 compared to PRE. Cortisol was significantly increased at IP and P15 compared to PRE. 12 rounds of 30 seconds of kettlebell swing exercise induced an acute increase in T, GH, and cortisol concentrations in resistance trained men. Additionally, this exercise protocol induced a large increase in HR and lactate concentration. Thus, the kettlebell swing exercise might provide an effective method for simultaneous endurance and resistance training. digital.library.unt.edu/ark:/67531/metadc407736/
Adolescent Behavior Problems and Interparental Conflict: the Moderating Role of Parent-child Attachment
The current study examined the role that parent-child attachment plays in the relationship between marital conflict and the development of behavior problems in adolescents. To evaluate the hypothesis that attachment moderates this relationship, 57 families were recruited via e-mail invitation sent to families that participated in local church youth groups, school organizations, and a treatment program designed for adolescents with behavior problems. One custodial parent and his/her adolescent child completed an online or paper version of a survey consisting of the Achenbach’s Behavior Checklists, the Inventory of Parent and Peer Attachment, and the Children’s Perception of Interparental Conflict Scale. Hypotheses were evaluated using Baron and Kenny’s (1986) procedures to test moderating effects with multiple regression analyses. Mother attachment demonstrated a significant moderation effect between the intensity of interparental conflict and the parent’s report of externalizing behavior problems. Specifically, at low conflict intensity levels, relative to low attachment security, high attachment security was associated with fewer externalizing behavior problems, whereas at high intensities of interparental conflict high attachment security was associated with more externalizing behavior problems. digital.library.unt.edu/ark:/67531/metadc407793/
An Age-based Etic Analysis of Orthographic Variation in Computer-mediated French Discourse
This study examines orthographic variation in synchronous computer-mediated French discourse. All nontraditional variations of selected frequently occuring items are quantified in order to provide an etic (i.e., from an external perspective) analysis. The primary variable of interest is age since this study focuses on providing a comparison of chat participants in their twenties versus those in their fifties. The widespread claim is that younger people communicate using more informal and/or nontraditional forms than older people; however, the results of the present study suggest that this is not always the case. The main finding of the present study is that the twentysomethings and the fiftysomethings produce the nontraditional orthography in a similar fashion in 52.2% of the terms, and in a non-similar fashion in 47.8% of the terms. Following the presentation and discussion of the results, directions for future research are provided. digital.library.unt.edu/ark:/67531/metadc407821/
American Indian Worldviews, Risk Perceptions and Disaster Planning: an Exploratory Study
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It is commonly assumed that when confronted with an imminent hazard that people will react rationally, and prepare for, or at least attempt to avoid, danger from pending disasters. However, this conventional wisdom is not as evident as it appears. People prepare for, react to, or take social action to avoid hazards when they perceive the risk of danger to be threatening enough to warrant action, providing one has the will, insight and resources to do so. However, not all people perceive risks similarly. Risk is perceived differently by different people which affects risk perception and responses to hazards. This dissertation explores the relationships between American Indian worldviews, risk perceptions and disaster planning. To carry out this research 28 American Indians were interviewed. The sample consists of 14 American Indians residing in a rural are on the northern plains and 14 urban American Indians. The results only partially support that worldview is linked to risk perception and subsequent disaster planning. Other factors found to relate to risk perception and disaster planning for this non-representative sample of American Indians include various forms of social vulnerability. digital.library.unt.edu/ark:/67531/metadc407742/
Analyzing Delinquency Among Kurdish Adolescents: a Test of Hirschi’s Social Bonding Theory
This study examines the mediating effect of social bonding on delinquent behavior among Kurdish teens. Major influences to the study of self concept and delinquency based on Hirschi’s social bonding theory are reviewed. The data was collected from a sample of 100 Kurdish teens attending a Gülen affiliated school (Private Çaglayan Murat Anatolian Science High School in Şanlıurfa, Turkey) and 100 Kurdish teens attending a public (non- Gülen) school (The Public High School in Diyarbakır, Turkey). There are two dependent variables for this research project: Involvement in major delinquency and involvement in minor delinquency. The components of social bonding attachment, involvement, commitment, and belief were used as independent variables. Participants’ age ranged between 16 to 18 years. I hypothesize that the relation between the social bonding elements and delinquency should be stronger in the case of Kurdish adolescents who are more attached to conventional Turkish society. Results from binary logistic regression analyses indicate that in the absence of bonding, Kurdish teenagers tend to engage in major and minor delinquent activities. For further exploration and results, the Gülen Movement was examined as an independent variable. Findings suggest a strong relationship between the Gülen Movement and Kurdish adolescents’ probability of involvement in either major or minor delinquent activities. Finally, several directions for future research on Hirschi’s social bonding theory are recommended and some implications are drawn for deterring Kurdish adolescents from becoming involved in delinquent actions. digital.library.unt.edu/ark:/67531/metadc407795/
Assessing Local Governments’ Debt Financing Strategies
This dissertation assesses the importance of a specific debt instrument, the Certifi- cate of Obligation in the state of Texas. It conceptualizes the Certificate of Obligation as a type of contractual debt that enables local governments to finance their capital projects. This dissertation is guided by three research questions: (1) What are the various types of debt instruments employed by local governments and what are their relative advantages? (2) How prevalent is the use of a specific debt instrument such as Certificates of Obligation? And why would some local governments prefer to issue them while others do not? (3) To what extent does the local institutional environment, e.g., the executive authority of city managers in the council-manager form of government, affect debt financing behaviors of local governments? To examine the first research question, we created a typology to represent four ideal types of borrowing methods: (1) Contractual Debt, (2) Voter Approval/Special Tax Debt, (3) Guaranteed, and (4) Non-Guaranteed Debts. The typology examines whether or not the state mandates the referendum requirement for the use of each of these debt instruments, and at the same time determines whether each debt instrument is secured by multiple or single revenue sources. Using data we collected among municipal governments in Texas, we conducted two empirical analyses. The first analysis tests the hypothesis that Certificates of Obligation have higher borrowing costs compared to GO bonds, since a GO bond is often issued under the pledge of the bond issuers’ full-faith credit and taxing authority. We employed a two-stage least square analysis to test the general proposition in the state of Texas. Based on 741 Certificates of Obligation and GO bonds issued between 2008 and 2011, our analyses show that Certificates of Obligation are likely to incur True Interest Costs (TIC) similar to those of GO bonds. The second analysis explores factors explaining the use of Certificates of Obligation in 225 Texas charter cities. Based on Heckman’s two-stage, we found that a local government’s decision to issue Certificates of Obligation to be partly explained by the characteristics of local population, i.e., median household income, population growth, and the percentage of senior citizens living in the jurisdiction. In the case of GO bonds, we found that population size, property tax rate, debt burden, and the percentage of population with at least a college education, to be an important determinant of GO bonds. The volume of GO issuance by local governments was also related to the level of regional competition, i.e., government density. Additionally, we found that local political institutions matter and that they affect debt financing behaviors of local governments. digital.library.unt.edu/ark:/67531/metadc407780/
Boosting for Learning From Imbalanced, Multiclass Data Sets
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In many real-world applications, it is common to have uneven number of examples among multiple classes. The data imbalance, however, usually complicates the learning process, especially for the minority classes, and results in deteriorated performance. Boosting methods were proposed to handle the imbalance problem. These methods need elongated training time and require diversity among the classifiers of the ensemble to achieve improved performance. Additionally, extending the boosting method to handle multi-class data sets is not straightforward. Examples of applications that suffer from imbalanced multi-class data can be found in face recognition, where tens of classes exist, and in capsule endoscopy, which suffers massive imbalance between the classes. This dissertation introduces RegBoost, a new boosting framework to address the imbalanced, multi-class problems. This method applies a weighted stratified sampling technique and incorporates a regularization term that accommodates multi-class data sets and automatically determines the error bound of each base classifier. The regularization parameter penalizes the classifier when it misclassifies instances that were correctly classified in the previous iteration. The parameter additionally reduces the bias towards majority classes. Experiments are conducted using 12 diverse data sets with moderate to high imbalance ratios. The results demonstrate superior performance of the proposed method compared to several state-of-the-art algorithms for imbalanced, multi-class classification problems. More importantly, the sensitivity improvement of the minority classes using RegBoost is accompanied with the improvement of the overall accuracy for all classes. With unpredictability regularization, a diverse group of classifiers are created and the maximum accuracy improvement reaches above 24%. Using stratified undersampling, RegBoost exhibits the best efficiency. The reduction in computational cost is significant reaching above 50%. As the volume of training data increase, the gain of efficiency with the proposed method becomes more significant. digital.library.unt.edu/ark:/67531/metadc407775/
Bridging the Theory-to-practice Gap: a Multivariate Correlational Study Exploring the Effects of a Graduate Online Learning Environment As a Community of Practice Framework
In this multivariate correlational study, the researcher examined the course culture of an online graduate course whose environment exhibited characteristics of a Community of practice (CoP). An online survey captured data used to explore the relationships among variables shown to describe a CoP in field environments and among student perceptions of their experience in the course culture. A canonical correlation analysis (CCA) and commonality analysis (CA) were conducted using five predictor variables and three criterion variables to evaluate the degree and direction of the relationships. The CCA revealed that the full model was significant, explaining approximately 74% of the variance among the two synthetic variates. Impact, faculty leadership, and connection were the largest contributors to the predictor variate. The criterion variate was primarily explained by value and perceived CoP, with exposure to the profession providing a smaller contribution. The CA confirmed these findings. Results from this study indicate that a CoP could be fostered in an online graduate course. The overall significance of the model indicates teachers can nurture an environment wherein graduate students will take the initiative to work with others to create and acquire knowledge that creates a sense of professional connection with each other and with the profession overall. The results of this study suggest further empirical research in implementing and assessing CoPs in online graduate courses is warranted. digital.library.unt.edu/ark:/67531/metadc407763/
Carbon Nanostructure Based Donor-acceptor Systems for Solar Energy Harvesting
Carbon nanostructure based functional hybrid molecules hold promise in solarenergy harvesting. Research presented in this dissertation systematically investigates building of various donor-acceptor nanohybrid systems utilizing enriched single walled carbon nanotube and graphene with redox and photoactive molecules such as fullerene, porphyrin, and phthalocyanine. Design, synthesis, and characterization of the donor-acceptor hybrid systems have been carefully performed via supramolecular binding strategies. Various spectroscopic studies have provided ample information in terms of establishment of the formation of donor-acceptor hybrids and their extent of interaction in solution and eventual rate of photoinduced electron and/or energy transfer. Electrochemical studies enabled construction of energy level diagram revealing energetic details of the possible different photochemical events supported by computational studies carried out to establish the HOMO-LUMO levels in the donor acceptor systems. Transient absorption studies confirmed formation of charge separated species in the donor-acceptor systems which have been supported by electron mediation experiments. Based on the photoelectrochemical studies, IPCE of 8% was reported for enriched SWCNT(7,6)-ZnP donor-acceptor systems. In summary, the present investigation on the various nanocarbon sensitized donor-acceptor hybrids substantiates tremendous prospect, that could very well become the next generation of materials in building efficient solar energy harvesting devices andphotocatalyst. digital.library.unt.edu/ark:/67531/metadc407823/
A Case Study of 1:1 Technology Policies in Four Texas High Schools and Their Relationship to Practice
With increasing emphasis on technology in schools, the importance of technology policies is great. This study investigated policies for four 1:1 secondary schools in Texas (schools with a ratio of one computing device per student), particularly with respect to the relationship of those policies to practice. The purpose of the study was to determine the current status of the National Education Technology Standards (NETS) essential conditions as reflected in policy and the relationship of those conditions to practice as measured through levels of technology usage and teaching innovation. Schools were selected through purposive, criterion sampling. Open-ended interviews were conducted with twelve participants (principals, technology directors, and superintendents). Policies were rated by campus principals and the researcher using a rubric based on the NETS essential conditions. Finally, surveys of proficiency and readiness measures were collected from 156 teachers using the School Technology and Readiness (STaR) instrument and the Levels of Teaching Innovation (LoTI) instrument. Interviews were transcribed and coded using structural and frequency coding. Policies were analyzed using magnitude coding and policy ratings. A qualitative analysis determined patterns between policy and practice. Quantitative data collected from surveys were measured against policy ratings and magnitude coding using bivariate correlation methods in SPSS. Quantitative analysis revealed two statistically significant relationships between policy and reported levels of practice in the classroom. Qualitative elements of the study from interviews and policy ratings revealed six findings that may explain a lack of correlation between policy and practice: a lack of ability for leadership to identify 1:1 program policy; lack among school leaders of perceived relationship between policy and practice; a belief among leaders that they are communicating policy to stakeholders even though they demonstrated difficulty in articulating policy; an inability to identify specific research-based theoretical foundations in policy; a lack of meaningful measurement of practices; and a lack of leadership at the same school to interpret policy similarly. A seventh finding revealed potential patterns between conditions that are addressed extensively in policy and evidence of those conditions in practice. Qualitative findings, in particular, contribute insights into disconnections between policy and practice in 1:1 settings. digital.library.unt.edu/ark:/67531/metadc407819/
Catered Learning: an Anthropological Approach to Understanding How Learning Styles of Participants and Teaching Styles of Instructors Affect Participants’ Perception, Motivation, and Performance
Organizations rely on their training departments to deliver adequate training for effective use of knowledge on the job to new and tenured employees. The transfer of learned knowledge and skills yields many positive outcomes for the employees, the trainers, and the organization as a whole. Such outcomes include improved productivity and efficiency, increased morale, work enjoyment, improved customer service, and improved shareholder satisfaction. In order to achieve these outcomes, training departments must employ skilled training personnel knowledgeable about curriculum design and creative with training delivery and learning environments. These requirements implementation will depends heavily on the experience level of training professionals. Training professionals need to understand their own learning styles and how to appropriately utilize strategies to target the various learning styles that exist in the classroom. Instructors must constantly monitor the learning environment and be able to make immediate changes to meet the needs of the participants when necessary. Participants themselves play an integral role in the effective transfer of learning from the classroom to the job. Learners’ backgrounds, life experiences, and motivation to learn are important considerations for designing a positive learning experience. When training programs cater to learners’ preferred learning styles with an appropriate learning environment in mind, the instructor, the learner, and the organization reap numerous benefits. More specifically, when learners’ learning styles are supported by their instructors’ teaching styles, the overall learning experience becomes optimized to the benefit of all stakeholders. digital.library.unt.edu/ark:/67531/metadc407835/
Characterization of Viscoelastic Properties of a Material Used for an Additive Manufacturing Method
Recent development of additive manufacturing technologies has led to lack of information on the base materials being used. A need arises to know the mechanical behaviors of these base materials so that it can be linked with macroscopic mechanical behaviors of 3D network structures manufactured from the 3D printer. The main objectives of my research are to characterize properties of a material for an additive manufacturing method (commonly referred to as 3D printing). Also, to model viscoelastic properties of Procast material that is obtained from 3D printer. For this purpose, a 3D CAD model is made using ProE and 3D printed using Projet HD3500. Series of uniaxial tensile tests, creep tests, and dynamic mechanical analysis are carried out to obtained viscoelastic behavior of Procast. Test data is fitted using various linear and nonlinear viscoelastic models. Validation of model is also carried out using tensile test data and frequency sweep data. Various other mechanical characterization have also been carried out in order to find density, melting temperature, glass transition temperature, and strain rate dependent elastic modulus of Procast material. It can be concluded that melting temperature of Procast material is around 337°C, the elastic modulus is around 0.7-0.8 GPa, and yield stress is around 16-19 MPa. digital.library.unt.edu/ark:/67531/metadc407787/
Churches, Social Service Access and Korean-american Elders: an Exploratory Study
This study examined how Korean co-ethnic churches serve as connections between Korean seniors and the agencies that offer social and health care services. The study developed from a pilot outreach program funded by the North Central Texas Council of Governments’ Area Agency on Aging (NCTAAA) to inform Korean seniors about Medicare-related programs between February and May of 2011. The results of the pilot program suggested that the Korean-American church can be an effective place for program outreach. The dissertation project, working in partnership with the NCTAAA and 2-1-1 services, further explored the use of Korean churches as a vehicle to connect Korean seniors to Extra Help (EH) and Medicare Saving Programs (MSP) and 2-1-1 services, a toll-free number for information about non-emergency health and social services. Fifty-three pastors were contacted to participate in a telephone survey and a face-to-face, in-depth semi-structured interview. Thirty telephone surveys and 11 face-to-face interviews were conducted. Five of the 30 pastors agreed to host program outreach presentations for the EH, MSP, and 2-1-1 services in their churches. Host churches tended to be more likely highly structured, regularly scheduled programs (e.g., Senior College) for seniors already in place. A total of 405 Korean seniors participated in the program outreach sessions. Five seniors received the EH application information, and 17 MSP application forms were distributed. Additionally, 28 seniors were assisted by phone, not only with the targeted programs, but also with other benefits information. Together, these outcomes indicate that the co-ethnic church can be a vehicle to connect Korean seniors to services offered by outside agencies. digital.library.unt.edu/ark:/67531/metadc407746/
A Comparison of Picture to Word Training and Word to Word Training on Native English Speaking College Students’ Acquisition of Italian Vocabulary
The current study assessed the effects of two teaching stimulus presentations, i.e. picture to word and word to word, used to teach second language vocabulary to college students. It also evaluated the emergence of untaught relations when picture to word and word to word were used separately as a teaching strategy. The findings showed picture to word training resulted in more untaught relations. Several aspects such time allotted for online quizzes, experimental and teaching arrangements and vocabulary complexity were suggested for future research. digital.library.unt.edu/ark:/67531/metadc407810/
A Comparison of Three Teacher Evaluation Methods and the Impact on College Readiness
Much attention in recent years has gone to the evaluation of teacher effectiveness, and some scholars have developed conceptual models to evaluate the effectiveness. The purpose of this study was to compare three teacher evaluation models – the Texas Professional Development Appraisal System (PDAS), the teacher index model (TI), and the value-added model (VAM) – to determine teacher effectiveness using student demographic and longitudinal academic data. Predictive data from students included economic disadvantage status, ethnicity, gender, participation in special education, limited English proficiency, and performance on Texas Assessment of Knowledge and Skills (TAKS). Data serving as dependent variables were scores from Scholastic Aptitude Test (SAT®) verbal/critical reasoning and mathematics. These data came from 1,714 students who were 9.7% Hispanic, 9.2% African American, and 81.2% White. The models were tested for 64 English language arts teachers and 109 mathematics teachers, using student examination scores from the SAT® verbal/critical reasoning and mathematics. The data were aligned for specific faculty members and the students whom they taught during the year of the study. The results of the study indicated that the TI and VAM explained approximately 42% of the variance in college entrance exam scores from the SAT® verbal/critical reasoning and mathematics (R2 = 0.418) across mathematics and English language arts teachers, whereas the TI model explained approximately 40% of the variance in the SAT® scores (R2 = 0.402). The difference, however, in the R-squared values between the VAM and the TI model was not statistically significant (t (169) = 1.84, p > 0.05), suggesting that both models provided similar results. The least effective model used to predict student success on college entrance exams was the PDAS, which is a state-adopted model currently in use in over 1,000 school districts in Texas, The teacher PDAS scores explained approximately 36% of the variance in student success on the SAT® (R2 = 0.359). The study provides school leadership with information about alternative methods of evaluating teacher effectiveness without difficult formulas or high costs associated with hiring statisticians. In addition, results indicate that the models vary significantly in the extent to which they can predict which teachers are most effective in preparing students for college. This study also emphasizes the critical need to provide teacher evaluations that align with student achievement on college entrance exams. digital.library.unt.edu/ark:/67531/metadc407840/
A Comprehensive Modeling Framework for Airborne Mobility
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Mobility models serve as the foundation for evaluating and designing airborne networks. Due to the significant impact of mobility models on the network performance, mobility models for airborne networks (ANs) must realistically capture the attributes of ANs. In this paper, I develop a comprehensive modeling framework for ANs. The work I have done is concluded as the following three parts. First, I perform a comprehensive and comparative analysis of AN mobility models and evaluate the models based on several metrics: 1) networking performance, 2) ability to capture the mobility attributes of ANs, 3) randomness levels and 4) associated applications. Second, I develop two 3D mobility models and realistic boundary models. The mobility models follow physical laws behind aircraft maneuvering and therefore capture the characteristics of aircraft trajectories. Third, I suggest an estimation procedure to extract parameters in one of the models that I developed from real flight test data. The good match between the estimated trajectories and real flight trajectories also validate the suitability of the model. The mobility models and the estimation procedure lead to the creation of “realistic” simulation and evaluation environment for airborne networks. digital.library.unt.edu/ark:/67531/metadc407760/
Correlates of Depression in Elderly Asians in the United States
The primary purpose of this study was to examine the correlation between depression and the personal characteristics of Asians who are 50 years or older. The secondary objective was to determine whether Asians 50 years or older living in the United States are more likely to be depressed than other ethnicities. The information for this study was secured from the National Health Interview Survey, spanning the years 2001 to 2010. In this study, I utilized the SAS-Callable SUDAAN statistical system. Multivariate regression was used to predict and determine significant correlations. The results indicated that Asians 50 and older living in the U.S. and who experience functional limitations, poor vision, hypertension, poor health, not married, and unemployed in previous year were in general more prone to depression. Furthermore, the study indicated that Asian elderly living the U.S. showed lower rates of depression than all non- Asian ethnicities. However when controlled for personal characteristics only Whites and Hispanics had higher depression incidences than Asian elderly. Recommendations for future studies include: conducting more micro and macro studies of Asian elders, such as in-depth case studies for each ethnicity, longitudinal studies of various Asian subgroups, and studies of Asian elderly with hypertension who have committed suicide. digital.library.unt.edu/ark:/67531/metadc407809/
The Current State of Us Higher Education Social Media Policies with Regard to Teaching and Learning: a Document Review Needs Assessment
In the world we live in today, having a social media account such as Facebook, LinkedIn, Twitter, or Google+ has become deeply ingrained in our society. The old way of networking with who you knew or who knew your family is no longer in play for many people. In the times in which we live, much personal and professional networking is completed via social media. The old way of networking had unwritten rules of engagement which, basically, were to be respectful and not cause any embarrassment within the network. Rules for best practice engagement are still evolving for this new way of using social media for personal and professional networking, which is the premise for the current study which addresses: the gap in U.S. university social media policies, with regard to teaching and learning. In order to gauge the policy interlude, a sample of over 49 U.S. university social media policies were gathered for a comprehensive document analysis. The Google search engine was used to find the policies, next the qualitative software NVivo10 was used to procure and analyze the policies. Additionally, triangulation was performed by three member checking volunteer investigators. The results of the study, disclosed that current policies are intended to train faculty and staff, in the legal and proper manner, in which the universities expect their employees to positively represent the sampled universities. digital.library.unt.edu/ark:/67531/metadc407802/
Design and Analysis of Novel Verifiable Voting Schemes
Free and fair elections are the basis for democracy, but conducting elections is not an easy task. Different groups of people are trying to influence the outcome of the election in their favor using the range of methods, from campaigning for a particular candidate to well-financed lobbying. Often the stakes are too high, and the methods are illegal. Two main properties of any voting scheme are the privacy of a voter’s choice and the integrity of the tally. Unfortunately, they are mutually exclusive. Integrity requires making elections transparent and auditable, but at the same time, we must preserve a voter’s privacy. It is always a trade-off between these two requirements. Current voting schemes favor privacy over auditability, and thus, they are vulnerable to voting fraud. I propose two novel voting systems that can achieve both privacy and verifiability. The first protocol is based on cryptographical primitives to ensure the integrity of the final tally and privacy of the voter. The second protocol is a simple paper-based voting scheme that achieves almost the same level of security without usage of cryptography. digital.library.unt.edu/ark:/67531/metadc407785/
Designing Tools to Probe the Calcium-dependent Function of Arabidopsis Tonneau2
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Plants possess unique features in many aspects of development. One of these features is seen in cell wall placement during cytokinesis, which is determined by the position of the preprophase band (PPB) and the subsequent expansion of the phragmoplast that deposits the new cell wall. During phragmoplast expansion, the phragmoplast tracks to the cortical division site, which was delineated by the PPB. Thus the position of the PPB determines the orientation of the division plane. In Arabidopsis thaliana, TONNEAU2 (TON2) is required for PPB formation and has been shown to interact with a type A subunit of the PP2A phosphatase in the yeast two-hybrid system. In Arabidopsis tonneau2 (ton2) mutants, abnormalities of the cortical microtubule cytoskeleton, such as disorganization of the interphase microtubule array and lack of PPB formation before mitosis markedly affects cell shape and arrangement as well as overall plant morphology. Loss of dcd1/add1, the maize ton2 homologues gives rise to a similar phenotype in Zea mays. The TON2 protein has two EF hand domains which are calcium-binding sites. Since calcium has been known to play key roles in several areas of plant functioning, the following question was raised: “Does calcium binding contribute to the localization and function of TONNEAU at the PPB?” To address this question, a series of constructs were generated to determine if TON2 binds calcium. Additionally, Ca2+ binding sites were mutated in constructs containing the TON2 gene fused to GFP or YPF. These constructs were then transformed into ton2 mutant plants and the localization of TON2 fusion protein and whether the construct is capable of rescuing the mutant phenotype were observed. Although, localization of TON2 to the PPB was not observed, the presence of the constructs were confirmed in the transformed plants using selection markers and by observing fluorescence under a confocal microscope. digital.library.unt.edu/ark:/67531/metadc407800/
Determination of Molecular Descriptors for Illegal Drugs by Gc-fid Using Abraham Solvation Model
The Abraham solvation parameter model is a good approach for analyzing and predicting biological activities and partitioning coefficients. The general solvation equation has been used to predict the solute property (SP) behavior of drug compounds between biological barriers. Gas chromatography (GC) retention time can be used to predict molecular descriptors, such as E, S, A, B & L for existing and newly developed drug compounds. In this research, six columns of different stationary phases were used to predict the Abraham molecular descriptors more accurately. The six stationary phases used were 5% phenylmethyl polysiloxane, 6% cyanopropylphenyl 94% dimethylpolysiloxane, 5% diphenyl 95% dimethylpolysiloxane, 100% dimethylpolysiloxane, polyethylene glycol and 35% diphenyl 65% dimethylpolysiloxane. Retention times (RT) of 75 compounds have been measured and logarithm of experimental average retention time Ln(RTexp) are calculated. The Abraham solvation model is then applied to predict the process coefficients of these compounds using the literature values of the molecular descriptors (Acree Compilation descriptors). Six correlation equations are built up as a training set for each of the six columns. The six equations are then used to predict the molecular descriptors of the illegal drugs as a test set. This work shows the ability to extract molecular information from a new compound by utilizing commonly used GC columns available with the desired stationary phases. One can simply run the new compound in GC using these columns to get the retention time. Plugging in the retention time into the developed equations for each of the column will predict the molecular descriptors for the test compound and will give some information about the properties of the compound. digital.library.unt.edu/ark:/67531/metadc407830/
Diaspora Philanthropy: Identity and Obligation Among Indian Engineers in the United States
Diaspora philanthropy to India has grown rapidly over the past several decades. However, little is known about the motivations of Indians living in the U.S. to donate philanthropically to India. Extant studies have either focused on quantitative analysis of diaspora philanthropy or qualitative research on the receiving of diaspora philanthropy in India. The motivations and strategies of the Indian diaspora in the U.S. have not been explored, particularly, the informal mechanisms and strategies of making philanthropic donations to India and the obligations that underlie the practice of diaspora philanthropy remain neglected in the existing studies on diaspora philanthropy. My research addressed this gap in the existing literature on diaspora philanthropy by conducting qualitative face-to-face in-depth interviews with a snowball sample of 25 Indian engineers in San Diego, California. In my study, it was found that Indians preferred to channel funds for philanthropy in India through friends and family because of lack of trust in formal organizations and greater confidence in the activities of friends and family in India due to familiarity and better accountability. It was also found that Indians felt indebted to Indian society and the Indian nation-state for the free and subsidized education they had received in India, and therefore felt obligated to make philanthropic contributions to India in order to redeem the debt that they owe to India. digital.library.unt.edu/ark:/67531/metadc407766/
Dramatizing Lynching and Labor Protest: Case Studies Examining How Theatre Reflected Minority Unrest in the 1920S and 30S
Theatre is widely unrecognized for the compelling influence it has held in society throughout history. In this thesis, I specifically examine the implications surrounding the social protest theatre of black and Jewish American minority communities in the first half of the twentieth century. I discuss how their historical circumstance, culture, and idiosyncratic natures caused them to choose agitated propaganda theatre as an avenue for protest. I delve into the similarities in circumstance, but their theatre case studies separate the two communities in the end. I present case studies of each community, beginning with anti-lynching plays of the 1920s that were written by black American playwrights both in response to white supremacist propaganda theatre and to assert a dignified representation of the black community. However, their plays and protest movement never developed a larger popular following. My next minority theatre case study is an examination of 1930s Jewish labor drama created in protest of popular anti-Semitic theatre and poor labor conditions. The Jewish community differs from the black community in their case because the racist propaganda was produced by a man who was Jewish. Another difference is that their protest theatre was on the commercial stage by this point because of a rise in a Jewish middle class and improvement of circumstance. Both the Jewish protest theatre and labor reform movements were more successful. My conclusion is a summation of black and Jewish American theatre of the era with a case study of collaboration between the communities in George Gershwin’s operetta about black Americans, Porgy and Bess. I conclude that these two communities eventually departed from circumstance and therefore had differing theatrical, political, and social experiences in America during the 1930s. digital.library.unt.edu/ark:/67531/metadc407832/
Dynamic Adhesion and Self-cleaning Mechanisms of Gecko Setae and Spatulae
Geckos can freely climb on walls and ceilings against their body weight at speed of over 1ms-1. Switching between attachment and detachment seem simple and easy for geckos, without considering the surface to be dry or wet, smooth or rough, dirty or clean. In addition, gecko can shed dirt particles during use, keeping the adhesive pads clean. Mimicking this biological system can lead to a new class of dry adhesives for various applications. However, gecko’s unique dry self-cleaning mechanism remains unknown, which impedes the development of self-cleaning dry adhesives. In this dissertation we provide new evidence and self-cleaning mechanism to explain how gecko shed particles and keep its sticky feet clean. First we studied the dynamic enhancement observed between micro-sized particles and substrate under dry and wet conditions. The adhesion force of soft (polystyrene) and hard (SiO2 and Al2O3) micro-particles on soft (polystyrene) and hard (fused silica and sapphire) substrates was measured using an atomic force microscope (AFM) with retraction (z-piezo) speed ranging over 4 orders of magnitude. The adhesion is strongly enhanced by the dynamic effect. When the retraction speeds varies from 0.02 µm/s to 156 µm/s, the adhesion force increases by 10% ~ 50% in dry nitrogen while it increases by 15%~70% in humid air. A dynamic model was developed to explain this dynamic effect, which agrees well with the experimental results. Similar dynamic enhancement was also observed in aqueous solution. The influence of dynamic factors related to the adhesion enhancement, such as particle inertia, viscoelastic deformations and crack propagation, was discussed to understand the dynamic enhancement mechanisms. Although particles show dynamic enhancement, Gecko fabrillar hair shows a totally different trend. The pull off forces of a single gecko seta and spatula was tested by AFM under different pull-off velocities. The result shows that both the spatula and the seta have a rate independent adhesion response in normal retraction, which is quite different from micro-particles. Further research indicated the shape of the contact area was a key factor to the dynamic effect. In order to verify this hypothesis, artificial gecko spatula made of glass fibers was nanofabricated by a focus ion beam (FIB) and tested by AFM. These manmade spatulae also show a rate independent adhesion response. The dynamic adhesion of a single gecko seta and spatula were simulated with finite element analysis and the results also confirm the rate independent phenomena.. In conclusion, self-cleaning is induced by dynamic effect during gecko locomotion. The relative dynamic adhesion change between particles and seta makes it possible for gecko to shed the dirt particles while walking.Finally, the fatigue property of gecko seta was examined with the atomic force microscope under cyclic attachment/detachment process, mimicking gecko running. The adhesion force versus cycles has been tested and evaluated. Fatigue mechanism of gecko seta was also analyzed based on the experimental findings. digital.library.unt.edu/ark:/67531/metadc407812/
Dynamic Precipitation of Second Phase Under Deformed Condition in Mg-nd Based Alloy
Magnesium alloys are the lightweight structural materials with high strength to weigh ratio that permits their application in fuel economy sensitive automobile industries. Among the several flavors of of Mg-alloys, precipitation hardenable Mg-rare earth (RE) based alloys have shown good potential due to their favorable creep resistance within a wide window of operating temperatures ranging from 150°C to 300°C. A key aspect of Mg-RE alloys is the presence of precipitate phases that leads to strengthening of such alloys. Several notable works, in literature, have been done to examine the formation of such precipitate phases. However, there are very few studies that evaluated the effect stress induced deformation on the precipitation in Mg-RE alloys. Therefore, the objective of this work is to examine influence of deformation on the precipitation of Mg-Nd based alloys. To address this problem, precipitation in two Mg-Nd based alloys, subjected to two different deformation conditions, and was examined via transmission electron microscopy (TEM) and atom probe tomography (APT). In first deformation condition, Md-2.6wt%Nd alloy was subjected to creep deformation (90MPa / 177ºC) to failure. Effect of stress-induced deformation was examined by comparing and contrasting with precipitation in non-creep tested specimens subjected to isothermal annealing (at 177ºC). In second condition, Mg-4.0Y-3.0Nd-0.5Zr (wt %) or WE43 alloy (with comparable Nd content as model Mg-Nd system) was subjected to hot rolling deformation at a sub-solvus temperature. digital.library.unt.edu/ark:/67531/metadc407807/
The Effect of It Process Support, Process Visualization and Process Characteristics on Process Outcomes
Business process re-engineering (part of the Business Process Management domain) is among the top three concerns of Information Technology (IT) leaders and is deemed to be one of many important IT leveraging opportunities. Two major challenges have been identified in relation to BPM and the use of IT. The first challenge is related to involving business process participants in process improvement initiatives using BPM systems. BPM technologies are considered to be primarily targeted for developers and not BPM users, and the need to engage process participants into process improvement initiatives is not addressed, contributing to the business-IT gap. The second challenge is related to potential de-skilling of knowledge workers when knowledge-intensive processes are automated and process knowledge resides in IT, rather than human process participants. The two identified challenges are not separate issues. Process participants need to be knowledgeable about the process in order to actively contribute to BPM initiatives, and the loss of process knowledge as a result of passive use of automated systems may further threaten their participation in process improvement. In response to the call for more research on the individual impacts of business process initiatives, the purpose of this dissertation study is to understand the relationship between IT configurations (particularly process support and process visualization), process characteristics and individual level process outcomes, such as task performance and process knowledge. In the development of the research model we rely on organizational knowledge creation literature and scaffolding in Vygotsky’s Zone of Proximal Development, business process modeling and workflow automation research, as well as research on the influence of IT on individual performance. The theoretical model is tested empirically in experimental settings using a series of two studies. In both studies participants were asked to complete tasks as part of a business process using different versions of a mock-up information system. Together, the studies evaluate the effect of IT process support, process visualization and process complexity on process participant performance and process knowledge. The results of the studies show the significant influence of IT process support on individual process outcomes. The studies indicate that task performance does increase but at the cost of users’ process knowledge. Process visualization however is shown to enhance user’s process knowledge in the event of no formal process training while having no negative impact on task performance. The key contribution of this research is that it suggests a practical way to counteract potential negative effects of IT process automation by converting the use of the information system into a learning experience, where the IT itself acts as a scaffold for the acquisition of process knowledge. The results have practical implications for the design of workflow automation systems, as well as for process training. digital.library.unt.edu/ark:/67531/metadc407777/
The Effect of Menthol on Nicotine Metabolism: a Cross Species Evaluation
The effect of menthol on nicotine metabolism was examined in liver S9 fractions of four different species and in the in vivo mouse model. The purpose of this study was to investigate three parameters: (1) biotransformation of nicotine to cotinine in various species (human, mouse, rat and trout) using in vitro methods; (2) to determine if the addition of menthol with nicotine altered biotransformation of nicotine to cotinine; (3) and to assess similar parameters in an in vivo mouse model. The major findings of this study include: (1) mice appear to metabolize nicotine, over time, in a manner similar to humans; (2) menthol decreased cotinine production, over time, after a single dose in mice; and (3) menthol increased cotinine production, over time, after repeated doses, in mice. digital.library.unt.edu/ark:/67531/metadc407773/
The Effect of Stock Splits on Small, Medium, and Large-sized Firms Before and After Decimalization
This study examines the impact of reducing tick size and, in particular decimalization on stock splits. Based on previous studies, this study examines hypotheses in the following three areas: first, market reaction around stock split announcement and ex-dates, second, the effect of tick size on liquidity after stock split ex-dates, and third, the effect of tick size on return volatility after stock split ex-dates. The impact of tick size on market reaction around split announcement and ex-dates is measured by abnormal returns and buy and hold abnormal returns (BHARs). Also, this study investigates the long term impact of decimalization on market reaction for small, medium, and large firms for the three different tick size periods. The effect of tick size on liquidity after stock split ex-dates is measured by turnover, relative bid ask spread, and market maker count. The effect of tick size on return volatility around stock split announcement and ex-dates is measured by return standard deviation. Also, this study investigates the long term impact of decimalization on volatility after split ex-dates for small, medium, and large firms for three different tick size periods. digital.library.unt.edu/ark:/67531/metadc407794/
The Effects of a Human Trafficking Prevention Workshop Package on Participant Written and Simulation Responses
This study evaluated the effects of a community workshop designed to teach community members about human trafficking prevention. Participants were trained to identify the critical and non-critical features of human trafficking and safe ways to respond to identified trafficking situations. A pre-post treatment design was used to assess the effects of a community workshop across written and verbal target behaviors. This included written responses as well as simulation assessments across five different trafficking scenarios. Results indicate that all participants engaged in more correct responding within the written assessment and asked specific relevant questions with greater confidence within the simulation assessment following training. However, social media and empathy responses following the workshop did not differ from baseline. This study is one of the first empirical studies aimed at formally evaluating the effects of human trafficking prevention workshops. Results are discussed in the context of instructional design, measurement of outcomes, and interdisciplinary collaboration. digital.library.unt.edu/ark:/67531/metadc407816/
Effects of Airway Pressure, Hypercapnia, and Hypoxia on Pulmonary Vagal Afferents in the Alligator (Alligator Misssissippiensis)
The American alligator (Alligator mississippiensis) is an aquatic diving reptile with a periodic breathing pattern. Previous work has identified pulmonary stretch receptors (PSR), both rapidly- and slowly-adapting, and intrapulmonary chemoreceptors (IPCs) that modulate breathing patterns in alligators. The purpose of the present study was to identify the effects of prolonged lung inflation and deflation (simulated dives) on PSR and/or IPC firing characteristics in the alligator. The effects of airway pressure, hypercapnia, and hypoxia on dynamic and static responses of pulmonary stretch receptors (PSR) were studied in juvenile alligators (mean mass = 246 g) at 24°C. Receptor activity appeared to be a mixture of slowly-adapting PSRs (SARs) and rapidly-adapting PSRs (RARs) with varying thresholds and degrees of adaptation, but no CO2 sensitivity. Dives were simulated in order to character receptor activity before, during, and after prolonged periods of lung inflation and deflation. Some stretch receptors showed a change in dynamic response, exhibiting inhibition for several breaths after 1 min of lung inflation, but were unaffected by prolonged deflation. For SAR, the post-dive inhibition was inhibited by CO2 and hypoxia alone. These airway stretch receptors may be involved in recovery of breathing patterns and lung volume during pre- and post-diving behavior and apneic periods in diving reptiles. These results suggest that inhibition of PSR firing following prolonged inflation may promote post-dive ventilation in alligators. digital.library.unt.edu/ark:/67531/metadc407750/
Emerging Ed-tech and Accessibility
Recent developments in the field of education have led to a proliferation of educational technologies (or “ed-tech”), yet access to educational content for students with special needs remains a challenge. This research study aims to assess the current state of accessibility in emerging ed-tech and to identify barriers in enabling educational content to be born accessible. Detailed discussions with various ed-tech platforms revealed less of a need for technical tools, but a more prevailing need for knowledge and education around accessibility – what it means and how best to incorporate accessibility into their platforms. The more experienced teams advocate incorporating accessibility into product development right from the design phase, while the younger teams expressed challenges in navigating accessibility laws and the dire need for easy-to-follow guidelines and best practices. A detailed review of educators' content creation processes reveals multiple dependencies in the ecosystem of ed-tech where partnerships and compatibilities are crucial in enabling accessibility throughout the process. Likewise, an urgent need exists for increasing awareness of accessibility among instructors authoring educational content using emerging ed-tech. digital.library.unt.edu/ark:/67531/metadc407857/
Energy Harvesting Wireless Piezoelectric Resonant Force Sensor
The piezoelectric energy harvester has become a new powering option for some low-power electronic devices such as MEMS (Micro Electrical Mechanical System) sensors. Piezoelectric materials can collect the ambient vibrations energy and convert it to electrical energy. This thesis is intended to demonstrate the behavior of a piezoelectric energy harvester system at elevated temperature from room temperature up to 82°C, and compares the system’s performance using different piezoelectric materials. The systems are structured with a Lead Magnesium Niobate-Lead Titanate (PMN-PT) single crystal patch bonded to an aluminum cantilever beam, Lead Indium Niobate-Lead Magnesium Niobate-Lead Titanate (PIN-PMN-PT) single crystal patch bonded to an aluminum cantilever beam and a bimorph cantilever beam which is made of Lead Zirconate Titanate (PZT). The results of this experimental study show the effects of the temperature on the operation frequency and output power of the piezoelectric energy harvesting system. The harvested electrical energy has been stored in storage circuits including a battery. Then, the stored energy has been used to power up the other part of the system, a wireless resonator force sensor, which uses frequency conversion techniques to convert the sensor’s ultrasonic signal to a microwave signal in order to transmit the signal wirelessly. digital.library.unt.edu/ark:/67531/metadc407829/
Evaluating the Content and Tone of Mental Health News Coverage in Market 40: a Content Analysis of Selected Internet Stories From Las Vegas Broadcasting News Outlets
The purpose of this research study is to analyze mental health related content on the three network affiliated stations in Las Vegas, Nevada. Online web stories from broadcast stations are analyzed in terms of the content and tone. These areas of analysis relate directly to the mass communication theories agenda setting and framing. Historically, mental health news reports have included content and tone that together can potentially create and further stigmatizing sentiments about those with mental illnesses. This study utilizes a chi square test to determine if a relationship exists between the three network affiliated stations, four a priori coded mental health content categories, and a rating of the overall tone using a value dimensions scale. Supplemental analyses include frequency evaluations of what has been called “people-first” versus “non-people first” language. By analyzing mental health related content at these three stations in the Las Vegas market this study aims to add heuristic value to the study of mental health reporting in broadcast news. This study will allow for additional research to further test relationships between stations, content, and tone in the Las Vegas and other news markets. Ultimately, this study provides analysis and discussion of the important role of agenda setting and framing in the news industry as it relates to the coverage of mental health related content. digital.library.unt.edu/ark:/67531/metadc407804/
Evaluating the Cultural Plan of Austin, Texas
This is a concurrent, mixed methods study of the impacts of Austin, Texas’s cultural plan, CreateAustin. In the study, trend analysis and a t-test were used to examine variables before and after the cultural plan was in place. At the same time, interviews with cultural planners were used to uncover other effects. My research addresses a gap in the literature between understanding the desired and actual outcomes of a cultural plan. Cultural plans are being developed by many communities in an effort to attract creative workers but they are rarely evaluated. Evaluation using a mixed methods approach is necessary to capture all the outcomes of a cultural plan, rather than the limited scope of impacts that are captured by qualitative or quantitative analyses alone. My analysis of the quantitative variables showed some significant differences between when the plan was in place and the years prior to its creation. Interviews with key stakeholders revealed the formation of new networks as a powerful outcome of the planning process. The results allowed me to gauge the overall impact of CreateAustin and make some observations about the cultural planning process in general, as well as uncover new directions for future research. digital.library.unt.edu/ark:/67531/metadc407737/
An Examination of Innovations in Alexander Scriabin’s Late Etudes for Piano
Alexander Scriabin (1872-1915) stands as one of the most unconventional twentieth-century Russian composers, particularly with respect to his piano works. The overwhelming majority of Scriabin's compositions—sixty-seven of his seventy-four published works—were written for solo piano. His etudes from 1905 forward are revolutionary, especially compared with his earlier Chopinesque style. Among Scriabin’s twenty-six etudes, his Op.49, No. 1 (1905), Op.56, No. 4 (1908) and the last three etudes of Op.65 (1912) date from his last period of composition. In the Op.49 etude, Scriabin started to abandon traditional tonality. He omitted the key signature altogether in the Op.56 etude. The final three etudes of Op.65 feature constant dissonances on ninths, sevenths and fifths. Alexander Scriabin’s last five etudes represent the culmination of his compositional development and innovations at the piano. Several factors coalesce in these etudes, including unusual harmony, bichords, non-tonal hierarchy, and structural symmetry. Most of these factors derive in some fashion from Scriabin’s increasing reliance upon the so-called “mystic chord” in his late works. This study will illustrate how Scriabin explored new sonorous and aesthetic ideas in his late etudes by means of these innovations. digital.library.unt.edu/ark:/67531/metadc407854/
An Examination of Mathematics Teachers’ Use of Student Data in Relationship to Student Academic Performance
Among educational researchers, important questions are being asked about how to improve mathematics instruction for elementary students. This study, conducted in a north Texas public school with 294 third- through fifth-grade students, ten teachers and three coaches, examined the relationship between students’ achievement in mathematics and the mathematics teaching and coaching instruction they received. Student achievement was measured by the Computer Adaptive Instrument (CAT), which is administered three times a year in the district and is the main criterion for students’ performance/movement in the district’s response to intervention program for mathematics. The response to intervention model employs student data to guide instruction and learning in the classroom and in supplemental sessions. The theoretical framework of the concerns based adoption model (CBAM) was the basis to investigate the concerns that mathematics teachers and coaches had in using the CAT student data to inform their instruction. The CAT data, based on item response theory, was the innovation. Unique in this study was the paralleling of teachers’ and coaches’ concerns and profiles for their use of the data with student scores using an empirical approach. Data were collected at three intervals through the Stages of Concerns Questionnaire, the Levels of Use interviews, and the Innovation Configuration Components Matrix from teachers and at three intervals student CAT-scaled scores. Multiple regression analyses with the concerns and CAT scores and levels of use and CAT scores were conducted to determine if relationships existed between the variables. The findings indicated that, overall, the teachers and coaches who scored high in personal concerns at the three data points remained at low levels of use or non-use of CAT data in their instruction. Only two teachers indicated movement from high intense personal concerns to high concerns regarding the impact on students. This correlated with their increased use of CAT at the three-collection points. The regression analyses indicated no correlations between the teachers’ and coaches’ concerns and the CAT and no correlations between their levels of data use and the CAT. At the exit interviews, patterns suggested that the presence of a change facilitator might have made a difference in their understanding and use of the CAT data ultimately impacting student achievement. This study sets a new precedent in the use of CBAM data and offers insights into the necessity of providing support and training in a change process. digital.library.unt.edu/ark:/67531/metadc407744/
Examining E-loyalty Model in Social Shopping Websites: the Impact of Social Shopping Website Quality on E-loyalty Formation
The purpose of this study is to examine the formation of customer e-loyalty to a social shopping website. The formation of customer e-loyalty to a social shopping website is examined based on cognitive-affective-conative-action loyalty framework. This study proposes that customer e-loyalty is strongly associated with website quality, e-satisfaction and participation. Seven website attributes (i.e., visual aesthetics, navigation, efficiency, user friendliness, security/privacy, entertainment and community driveness) identified in previous research are employed to measure website quality that affects e-loyalty formation. There are 449 data collected from a southwestern university in the U.S., but only the responses from 333 Pinterest users are used to test the hypotheses. Exploratory factor analysis is used to identify dimensionality of social shopping website attributes, and multiple regression and linear regression analysis are conducted to test hypotheses in this study. Results of the study indicate that five significant factors including efficiency, user friendliness, security/privacy, entertainment and community driveness are directly associated with customer e-loyalty. Indeed, such website quality factors as the determinant of cognitive e-loyalty directly affect overall customer satisfaction (affective e-loyalty), customer purchase/return intention to the website (conative e-loyalty), and customer participation, positive eWOM and co-shopping (action e-loyalty). The findings of this study have provided evidence that social shopping website quality dimensions are directly associated with customer e-loyalty to the website. Also, the findings have shown important implications to ensure quality website attributes to increase customer loyalty to a social shopping website. digital.library.unt.edu/ark:/67531/metadc407782/
Examining High School Coaches’ Likelihood to Refer To, Interest in Working With, and Plans to Hire a Sport Psychologist
The primary goal of the current study was to extend previous research suggesting that coaches are the primary gatekeepers who may be a barrier to working with athletes by examining high school coaches likelihood to refer to, interest in, and intention to hire a sport psychologist. Specifically, the current study examined relationships between high school coaches’ sex, age, and type of sport coached (i.e., contact vs. non-contact) and their likelihood to refer athletes to a sport psychologist for a variety of presenting issues (i.e., poor attentional focus, poor leadership, family issues, etc.). It also examined relationships between coaches’ sex, age, and type of sport coached (i.e., contact vs. non-contact) and their interest in working with a sport psychologist. Finally, the study examined reasons why coaches did not plan to hire a sport psychologist. An examination of the possible reasons that high school coaches do not plan to hire a sport psychologist served an exploratory purpose. Participants included 450 coaches who coached high school sports in the United States. Results indicated that female coaches and non-contact sport coaches were more likely to refer athletes to a sport psychologist for a variety of referral issues than male coaches and coaches of contact sports. Similarly, significantly more female coaches and non-contact sport coaches showed interest in working with a sport psychologist than male coaches and coaches of contact sports. Coaches who did not plan to hire a sport psychologist reported that cost, lack authority to hire, and lack of availability as primary reasons. Implications of the findings, limitations, and future directions are discussed. digital.library.unt.edu/ark:/67531/metadc407762/
Exploring the Impacts of Fashion Blog Type and Message Type on Female Consumer Response Towards the Brand
The current study examines the influences of blog type and blog message type on consumers’ perceptions of brand credibility and brand similarity. Additionally, the study seeks to understand the interaction effects of blog type and message type on brand credibility and brand similarity and on consumer engagement with a blog. The findings reveal that message type, specifically product message, is an important consideration when marketers want to illustrate similarities between the brand and consumers. Additionally, it was found that product messages should be considered when encouraging consumer engagement with a blog. However, blog type did not have an effect on consumer perceptions of brand credibility and similarity or consumer engagement. digital.library.unt.edu/ark:/67531/metadc407834/
The Extent of Autism Knowledge of Novice Alternatively Certified Special Education Teachers in Texas
An increase in the prevalence rate of autism is not necessarily matched by a concurrent increase in the rate of highly qualified special education teachers. The low ratio of highly qualified teachers to the number of students with autism has resulted in chronic teacher shortages in this area. Alternative certification is used as a mechanism to alleviate the demand for highly qualified teachers in special education. However, alternative certification routes have often left novice teachers underprepared for teaching students with autism, more specifically in the implementation of evidence-based practices necessary for instructional effectiveness. The purposes of the study were: a) to assess the knowledge of novice alternatively certified (AC) teachers in the area of autism education; and b) to determine the extent to which age, credit hours of instruction, formal hours of instruction, amount of professional development, and number of students with autism predict the variance in knowledge scores. Participants included all novice (i.e., first-and second-year) alternatively certified special education teachers in the state of Texas. Data were collected through an electronic survey instrument disseminated state-wide to approximately 33 individuals. Multiple regression was conducted in order to determine the strongest predictors of autism knowledge scores. In addition, a multi-way ANOVA was performed to identify differences between groups. The largest predictor of knowledge of autism was hours engaged in self-directed learning. Overall, AC programs in Texas need to provide basic and core content in the area of autism to increase the knowledge of novice teachers. digital.library.unt.edu/ark:/67531/metadc407790/
Facebook Brand Page: an Exploratory Study of Facebook Brand Page Attributes and Their Influence on Purchase Intentions
This study explored attributes of a Facebook brand page (FBP). Seven variables were derived from the framework and applied to FBPs. The goals of this research were to discover which attributes contribute to a successful FBP, determine which attributes increase purchase intentions, and help marketers determine where to focus their efforts. A total of 421 surveys were gathered from men and women ages 18 and older. The methods of this research included factor analysis and multiple regression analysis. Results yielded two loading factors for the trustworthiness variable and supported hypotheses of trustworthiness increasing purchase intentions. It was also discovered that participation positively influences purchase intentions. It is advised that information content be monitored to avoid information overload. digital.library.unt.edu/ark:/67531/metadc407753/
Facebook Marketing for Fashion Apparel Brands: Effect of Other Consumer Postings and Type of Brand Comment on Brand Trust and Purchase Intention
Social networking sites are a major networking tool for consumer interactions as they provide a platform for communication, socialization, and learning activity. Subsequently, social media has become an important marketing tool for advertising companies’ messages. As a result, fashion brands such as H&M and Victoria’s Secret started to show more brand ads on Facebook. Facebook is one of the most powerful social networking sties due to its ability to reach to broad consumer groups through a brand page. However, research regarding this topic is limited as the social networking sites is relatively a new phenomenon. Therefore, the purpose of this research is to examine the effect of the brand’s comments in attenuating (enhancing) negative (positive) influence of other consumer’s postings on brand trust and purchase intention of other consumer’s postings on social media. Findings from this study revealed that there is no moderating effect of brand comments of the relationship between other consumer’s postings and brand trust, while positive other consumer’s postings has a significant effect on consumers’ brand trust. Also, there were no significant differences among other consumer’s postings, brand comments and purchase intention relationships. These findings add to the previous literature explains that brand should interact with consumers frequently in order to induce positive other consumer’s postings to develop brand trust. By using the consumer socialization theory to investigate Facebook marketing, this study provides insights and information on consumer attitudes and behaviors related to Facebook brand page. digital.library.unt.edu/ark:/67531/metadc407828/
Field and Laboratory Fish Tissue Accumulation of Carbamazepine and Amiodarone
The goals of this dissertation work were to assess the bioaccumulation potential of carbamazepine and amiodarone, two widely used ionizable pharmaceutical compounds that possess mid-range and high LogD values, respectively, and to evaluate alternative methods to assess chemical accumulation in bluntnose minnows, catfish, and tilapia. Results indicated that carbamazepine does not appreciably bioaccumulate in fish tissue with BCFk and BAF carbamazepine values < 10. Amiodarone, however, with a log D of 5.87 at pH 7.4, accumulated in fish tissues with kinetic BCF values <2,400. Collectively, the data suggest that full and abbreviated laboratory-derived BCFs, BCFMs derived from S9 loss-of-parent assays, as well as field BAF values are similar for each of the two drugs. In summary, the results from this dissertation indicated: 1) The reduced design BCF test is a good estimate for the traditional OECD 305 test. 2) In vitro S9 metabolism assays provide comparable BCF estimates to the OECD 305 test. 3) Metabolism may play a large role in the accumulation of drugs in fish. 4) Reduced BCF tests and in vitro assays are cost effective and can reduce vertebrate testing. digital.library.unt.edu/ark:/67531/metadc407838/
From Aspiration to Attainment: African American Community College Transfer Student Experiences Through Baccalaureate Degree Attainment
The purpose of this dissertation was to explore African American community college transfer student experiences through baccalaureate degree completion. The current study used qualitative methods to examine the experiences and perceptions of eighteen African American community college transfer students who recently graduated or were within 30 credit hours of graduating from a four-year university in Texas. Ten female and eight male students, ranging in age from 21 to 56 years old, with an average age of 28, composed the sample. Data were collected through semi-structured interviews which were transcribed and analyzed based on an integrated conceptual model of Padilla’s (1999) Model of Minority Student Success and Yosso’s (2005) Community Cultural Wealth Model. Findings suggest that African American community college transfer student experiences are very similar to transfer student experiences revealed in current literature. However, findings indicate students perceive their experiences differ from student of other races/ethnicities when dealing with negative stereotypes, lack of role models, and racial bias. Findings also suggest African American community college transfer student persist by employing transfer student capital, familial, aspirational, and resistant capital to learn how the traverse transfer, transition, and persistence through baccalaureate degree attainment. digital.library.unt.edu/ark:/67531/metadc407745/
Functional Characterization of Mtnip/latd’s Biochemical and Biological Function
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Symbiotic nitrogen fixation occurs in plants harboring nitrogen-fixing bacteria within the plant tissue. The most widely studied association is between the legumes and rhizobia. In this relationship the plant (legumes) provides the bacteria (rhizobia) with reduced carbon derived from photosynthesis in exchange for reduced atmospheric nitrogen. This allows the plant to survive in soil, which is low in available of nitrogen. Rhizobia infect and enter plant root and reside in organs known as nodules. In the nodules the bacteria fix atmospheric nitrogen. The association between the legume, Medicago truncatula and the bacteria Sinorhizobium meliloti, has been studied in detail. Medicago mutants that have defects in nodulation help us understand the process of nitrogen fixation better. One such mutant is the Mtnip-1. Mtnip-1 plants respond to S. meliloti by producing abnormal nodules in which numerous aberrant infection threads are produced, with very rare rhizobial release into host plant cells. The mutant plant Mtnip-1 has an abnormal defense-like response in root nodules as well as defects in lateral root development. Three alleles of the Mtnip/latd mutants, Mtnip-1, Mtlatd and Mtnip-3 show different degrees of severity in their phenotype. Phylogenetic analysis showed that MtNIP/LATD encodes a protein belonging to the NRT1(PTR) family of nitrate, peptide, dicarboxylate and phytohprmone transporters. Experiments with Mtnip/latd mutants demonstrats a defective nitrate response associated with low (250 μM) external nitrate concentration rather than high (5 mM) nitrate concentration. This suggests that the mutants have defective nitrate transport. To test if MtNIP/LATD was a nitrate transporter, Xenopus laevis oocytes and Arabidopsis thaliana mutant plants Atchl1-5, defective in a major nitrate transporter AtNRT1.1(CHL1), were used as surrogate expression systems. Heterologous expression of MtNIP/LATD in X. laevis oocytes and Atchl1-5 mutant plants conferred on them the ability to take up nitrate from external media with high affinity, thus demonstrating that MtNIP/LATD was a high affinity nitrate transporter. Km for MtNIP/LATD was determined to be approximately160 μM in the X. laevis system and 113 μM in the Arabidopsis Atchl1-5 mutant lines thus supporting the previous observation of MtNIP/LATD being a high affinity nitrate transporter. X. laevis expressing the mutant Mtnip-1 and Mtlatd, were unable to transport nitrate. However X. laevis oocytes, expressing the less severe mutant allele Mtnip-3 were able to transport nitrate suggesting another role of the Mtnip/latd besides high affinity nitrate transport. Experimental evidence suggested that MtNIP/LATD might transport another substrate beside nitrate. MtNIP/LATD levels are regulated by phytohormones. Experiments performed with ABA (abscisic acid), IAA (indole acetic acid) and histidine as substrates in X. laevis system show that the MtNIP/LATD mRNA injected oocytes efflux IAA but do not transport histidine or ABA. When wild type A17 and mutant Mtnip-1 and Mtnip-3 plants, grown in the presence of different sources of nitrogen were screened in herbicide chlorate, a structural analog of nitrate, the A17 and Mtnip-3 mutant showed levels of susceptibility that was different from mutant Mtnip-1 lines. Evidence suggested that the amount of chlorate transported into the plants were regulated by the C:N status of the A17 and Mtnip-3 plants. This regulation was missing in the Mtnip-1 lines thus suggesting a sensor function of MtNIP/LATD gene. digital.library.unt.edu/ark:/67531/metadc407822/
Funds of Knowledge in a Hispanic Household: a Case Study of Family Experiences, Values, and Connections to Education
Traditionally, the field of education has often adopted a negative perspective in their views of minority families’ contributions to the educational progress of their children. However, research embodying the theoretical framework of ‘funds of knowledge’ attempts to counter that model through its assertion that all families possess extensive bodies of knowledge that have developed through social, historical, and cultural contexts. Teachers carry out studies of familial funds of knowledge in order to understand how family experiences shape the knowledge that a child brings to the classroom. There is then, the potential to use that body of knowledge to create meaningful learning experiences that connect prior understanding and experiences to classroom practice. This research served as a case study of the funds of knowledge existing in the home of a Hispanic family and the connections that existed between that knowledge and literacy. The results indicated that the family possessed extensive funds of knowledge that developed through their historical, cultural, and social experiences. They often used family networks, as well as formal and informal literacy experiences to share this knowledge with their children. A key component of the literacy value system that they communicated resulted from a desire to maintain aspects of their culture and heritage through maintaining and improving their children’s reading and linguistic abilities in Spanish. Furthermore, along with their emphasis on Spanish literacy, they held aspirations for their children related to familial and educational values that often stemmed from their expressed desire for their children to lead lives with greater opportunities and positive examples than they had experienced. digital.library.unt.edu/ark:/67531/metadc407772/
The Glass Is Neither Half Full Nor Empty, It Is Shattered: a Prospective Study of Shattered Assumptions Theory and Psychological Flexibility
Shattered assumptions theory posits that each individual has a core set of assumptions about the world and the self, often termed the assumptive world which includes: the world is a benevolent place, the world is meaningful, and the self is worthy. Experiencing a traumatic event is believed to lead individuals to question these assumptions in light of the new contradictory information that causes the assumptive world to shatter, leaving the individual to rebuild a more negative perception of the world and themselves. This rebuilding of a fragile new set of core beliefs is believed to be a cause of posttraumatic stress disorder (PTSD) symptoms. Although shattered assumptions theory has been widely accepted in the field of trauma psychology, the shattering of the assumptive world has not been empirically supported due to measurement issues and poor research designs. The current study implemented a prospective design to assess a new measure of the individual’s assumptive world when there is an intervening trauma. In a college sample (N = 336), individuals who experienced a traumatic event over the course of the semester (n = 40) evidenced decreases in optimism in their assumptive worlds, in comparison to individuals who did not experience a traumatic event. The results suggest there is a limited shattering of the assumptive world for those who experienced a traumatic event. Applications, limitations and future directions are discussed. digital.library.unt.edu/ark:/67531/metadc407756/
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