Latest content added for UNT Libraries Digital Collections

Stimuli-responsive microgels for self-assembled crystalline structures and controlled drug release.

Thu, 19 Nov 2009 20:18:30 -0600

Tissue response to PNIPAM and HPC nanoparticles has been studied by implantation method. The results suggest that both PNIAPM and HPC nanoparticles possess good biocompatibility and they may serve as a good carrier for the applications of controlled delivery. Rheological properties of dispersions of IPN microgels composed of PNIPAM and PAAc have been studied. It is found that the IPN microgel dispersion can undergo a sol-gel transition at temperature above 33°C. In vivo drug release experiments suggest that the gelation procedure creates a diffusion barrier and thus leads to slow release. An emulsion method has been used to grow columnar crystals by mixing PNIPAM microgel dispersions with organic solvents. Effect of both temperature and microgel concentration on formation of columnar crystals has been studied. PNIPAM-co-NMA microgels have been used for the fabrication of crystalline hydrogel films by self-crosslinking microgels. The hydrogel film exhibits an iridescent. The thermally responsive properties and mechanical properties of this film have been studied. Melting temperature (Tm) of colloidal crystals self-assembled with PNIPAM-co-AAc microgels has been investigated as a function of pH, salt concentration and microgel concentration. It is revealed that Tm increases as pH value increases; Tm decreases with increase of salt concentration; Tm increases as microgel concentration increases. Phase behavior of PNIPAM-co-HEAc microgel dispersions has been investigated. It is observed that these microgel dispersions exhibit liquid, crystal, and glass phase. As microgel size increases, crystal phase shifts to low concentration range. As temperature increases, crystal phase shifts to high concentration ranges. These colloidal crystals can be stabilized by NaOH-induced gelation. Effect of NaOH concentration on formation of physical gelation has been investigated.

The Assimilation of Baroque Elements in Ferruccio Busoni's Compositions as Exemplified by the Fantasia nach Bach and the Toccata

Thu, 19 Nov 2009 20:18:28 -0600

Reliable communication over the noisy channel has become one of the major concerns in the field of digital wireless communications. The low density parity check codes (LDPC) has gained lot of attention recently because of their excellent error-correcting capacity. It was first proposed by Robert G. Gallager in 1960. LDPC codes belong to the class of linear block codes. Near capacity performance is achievable on a large collection of data transmission and storage.In my thesis I have focused on hardware implementation of (3, 6) - regular LDPC codes. A fully parallel decoder will require too high complexity of hardware realization. Partly parallel decoder has the advantage of effective compromise between decoding throughput and high hardware complexity. The decoding of the codeword follows the belief propagation alias probability propagation algorithm in log domain. A 9216 bit, (3, 6) regular LDPC code with code rate ½ was implemented on FPGA targeting Xilinx Virtex 4 XC4VLX80 device with package FF1148. This decoder achieves a maximum throughput of 82 Mbps. The entire model was designed in VHDL in the Xilinx ISE 9.2 environment.

Immediate and Subsequent Effects of Fixed-Time Delivery of Therapist Attention on Problem Behavior Maintained by Attention

Thu, 19 Nov 2009 20:18:27 -0600

The purpose of the current study was to investigate the immediate and subsequent effects of fixed-time attention on problem behavior maintained by therapist attention utilizing a three-component multiple-schedule design. The treatment analysis indicated that fixed-time attention produced a significant immediate decrease in the frequency of physically disruptive behavior (PDB), represented by low frequencies of PDB in Component 2, as well as a continued subsequent effect, represented by lower frequencies of problem behavior in Component 3 when compared to Component 1. The possible behavioral mechanisms responsible for the observed suppression in Component 2 of the treatment analysis are discussed. Evidence of behavioral contrast was observed in Components 1 and 3 of the treatment analysis in conditions in which Component 2 contained a fixed-time schedule of stimulus delivery. In addition, limitations and future research are outlined.

Metabolic Syndrome and Psychosocial Factors

Thu, 19 Nov 2009 20:18:27 -0600

Metabolic syndrome is a constellation of risk factors, including abdominal obesity, hypertriglyceridemia, low HDL cholesterol, high blood pressure, and high fasting glucose, that commonly cluster together and can result in cardiovascular disease. The prevalence of metabolic syndrome and the components that comprise the syndrome vary by age and by racial/ethnic group. In addition, previous research has indicated that the risk factors contributing to metabolic syndrome may be exacerbated by exposure to perceived stress. This study utilized data from the 2002, 2004, and 2006 Health and Retirement Study (HRS) and National Health and Nutrition Examination Survey (NHANES) data sets. It was hypothesized that depression and anxiety (conceptualized as stress in this study) increase the risk of presenting with metabolic syndrome while social support decreases the risk of metabolic syndrome. While results of cross-sectional analysis do not indicate a significant relationship between depression and metabolic syndrome (t = -.84, ns), longitudinal analysis does indicate a significant relationship between depression and metabolic syndrome over time (t = -5.20, p <.001). However, anxiety is not significantly related to metabolic syndrome when the relationship is examined through cross-sectional analysis (t = -1.51, ns) and longitudinal analysis (χ² = 13.83, ns). Similarly, social support is not significantly related to metabolic syndrome when examined in cross-sectional (χ² = .63, ns) and longitudinal (t = 1.53, ns) analysis. Although level of stress is not significantly related to metabolic syndrome as a whole, there is a significant relationship between stress and both triglyceride level (t = -2.94, p = .003) and blood glucose level (t = -3.26, p = .001).

The Assimilation of Baroque Elements in Ferruccio Busoni's Compositions as Exemplified by the Fantasia nach Bach and the Toccata

Thu, 19 Nov 2009 20:18:26 -0600

Ferruccio Busoni (1866-1924) has a firmly established reputation as one of the giant pianists of his age, yet his compositions are largely neglected both in musicological circles and on the concert stage. A better understanding of his thought processes might lead to a greater appreciation of his art, and the acknowledgement of his reverence for the music of Bach is an important key to such an understanding. Busoni's Fantasia nach Bach and Toccata, although two decidedly dissimilar compositions in terms of purpose and conception, represent two manifestations of Busoni's respect for Bach, whether it be in the form of assimilating Bach's compositions into one of his own, or by creating an original work to the same mold as some of Bach's works.

Deliberative Democracy, Divided Societies, and the Case of Appalachia

Thu, 19 Nov 2009 20:18:26 -0600

Theories of deliberative democracy, which emphasize open-mindedness and cooperative dialogue, confront serious challenges in deeply divided political populations constituted by polarized citizens unwilling to work together on issues they collectively face. The case of mountaintop removal coal mining in Appalachia makes this clear. In my thesis, I argue that such empirical challenges are serious, yet do not compromise the normative desirability of deliberative democracy because communicative mechanisms can help transform adversarial perspectives into workable, deliberative ones. To realize this potential in divided societies, mechanisms must focus on healing and reconciliation, a point under-theorized by deliberativists who do not take seriously enough the feminist critique of public-private dualisms that illuminates political dimensions of such embodied processes. Ultimately, only a distinctly two-stage process of public deliberation in divided populations, beginning with mechanisms for healing and trust building, will give rise to the self-transformation necessary for second-stage deliberation aimed at collectively binding decisions.

A Performance Guide to Luigi Nono's Post-Prae-Ludium No. 1 "Per Donau"

Thu, 19 Nov 2009 20:18:25 -0600

Luigi Nono's work Post-Prae-Ludium No.1 "per Donau" represents a model for the emerging genre of electroacoustic tuba music. It is important to preserve this electroacoustic work because of its value to the tuba literature. Not only is it one of the first electroacoustic works for the tuba, but it also was composed by a man who is highly regarded in the field of music composition. Its preservation will be difficult because of the rapid advancement in technology. Within the last three decades of existence, the technology has evolved three times. An examination of the performance practice in Post-Prae-Ludium was undertaken to understand the demand on the performer required to play this work. This study will look at both non-traditional performance practices, as well as an inherent problem of how the advancement of technology can actually threaten the survival of a work dependent upon a specific version of electronic technology. Nono worked in collaboration with Giancarlo Schiaffini to compose a work for tuba and live electronics. Correspondence with Schiaffini has provided his thoughts on the collaboration of Post-Prae-Ludium with Nono and given a better understanding of how to perform the work. Technology will change, and these current adaptations of Post-Prae-Ludium may not be valid in one or two decades. However, with the description and instruction given by Nono and Schiaffini, in addition to recordings made of Post-Prae-Ludium, there is a record from which to reproduce this work. This study provides a source allowing performers to reproduce this work, thereby preserving it for future performers.

Using Diffusion of Innovations to Explore Digital Gaming in Undergraduate Library Instruction

Thu, 19 Nov 2009 20:18:25 -0600

Digital games and simulations are receiving considerable notice within the Library and Information Science (LIS) community. This study adds to the depth of knowledge in this area by providing research on the likelihood a hypothetical digital game delivery method for library instruction achieves sufficient adoption to justify its development. Furthermore, this knowledge will assist decision making processes for individuals debating the current or potential role of digital gaming at their institutions. In this mixed methods study, over 300 undergraduates were surveyed about their technology preferences, including digital gaming, for delivery of two forms of academic library instruction. The two forms of library instruction were (a) providing users with spatial information on physical library layout, and (b) educating users on information literacy topics and skills. Observational data was collected during the survey sessions, occurring at face-to-face library instruction sessions. Self-selected survey participants were also interviewed to further probe their survey responses. Rogers' Diffusion of Innovations was the theoretical foundation to this research. The primary innovation of study was the digital game delivery method. Detailed analysis of the survey-based data set included three nonparametric scaling methods: 1) rank-sum scaling; 2) circular triad analysis; and 3) multidimensional preference mapping. Content analysis of the observations and semi-structured interviews also occurred. Major outcomes were 1) the digital game delivery method achieved mediocre preference across both questions; 2) the audiovisual delivery method received the highest overall preference ranking; and 3) overall preference for the audio-only delivery method was remarkably low. The most important theme across the observational data was the participants' waning attention during the face-to-face library instruction sessions. The most important outcome from the semi-structured interviews was interviewees' stated appreciation for useful technologies. Over 95% of participants were so-called digital natives, that is, born post-1980. Rogers' assertion that age plays a minor role in predicting technology adoption appears warranted, since the more innovative digital game delivery method achieved mediocre overall preference.

Disturbing Nature's Beauty: Environmental Aesthetics in a New Ecological Paradigm

Thu, 19 Nov 2009 20:18:24 -0600

An ecological paradigm shift from the "balance of nature" to the "flux of nature" will change the way we aesthetically appreciate nature if we adopt scientific cognitivism-the view that aesthetic appreciation of nature must be informed by scientific knowledge. Aesthetic judgments are subjective, though we talk about aesthetic qualities as if they were objectively inherent in objects, events, or environments. Aesthetic judgments regarding nature are correct insofar as they are part of a community consensus regarding the currently dominant scientific paradigm. Ecological science is grounded in metaphors: nature is a divine order, a machine, an organism, a community, or a cybernetic system. These metaphors stimulate and guide scientific practice, but do not exist independent of a conceptual framework. They are at most useful fictions in terms of how they reflect the values underlying a paradigm. Contemporary ecology is a science driven more by aesthetic than metaphysical considerations. I review concepts in the history of nature aesthetics such as the picturesque, the sublime, disinterestedness, and formalism. I propose an analogy: just as knowledge of art history and theory should inform aesthetic appreciation of art, knowledge of natural history and ecological theory should inform aesthetic appreciation of nature. The "framing problem," is the problem that natural environments are not discrete objects, so knowing what to focus on in an environment is difficult. The "fusion problem" is the problem of how to fuse the sensory aspect of aesthetic appreciation with highly theoretical scientific knowledge. I resolve these two problems by defending a normative version of the theory-laden observation thesis. Positive aesthetics is the view that insofar as nature is untouched by humans, it is always beautiful and never ugly. I defend an amended and updated version of positive aesthetics that is consistent with the central elements of contemporary ecology, and emphasize the heuristic, exegetical, and pedagogical roles aesthetic qualities play in ecological science.

Accident versus Essence: Investigating the Relationship Among Information Systems Development and Requirements Capabilities and Perceptions of Enterprise Architecture

Thu, 19 Nov 2009 20:18:24 -0600

Information systems (IS) are indelibly linked to the global economy and are indispensable to society and organizations. Despite the decisive function of IS in organizations today, IS development problems continue to plague organizations. The failure to get the system requirements right is considered to be one of the primary, if not the most significant, reasons for this high IS failure rate. Getting requirements right is most notably identified with Frederick Brooks' contention that requirements are the essence of what IT professionals do, all the rest being accidents or risk management. However, enterprise architecture (EA) may also provide the discipline to bridge the gap between effective requirements, organizational objectives, and the actual IS implementations. The intent of this research is to examine the relationship between IS development capabilities and requirements analysis and design capabilities within the context of enterprise architecture. To accomplish this, a survey of IT professionals within the Society for Information Management (SIM) was conducted. Results indicate support for the hypothesized relationship between IS development and requirements capabilities. The hypothesized relationships with the organizational demographics were not supported nor was the hypothesized positive relationship between requirements capabilities and EA perceptions. However, the nature of the relationship of requirements and EA provided important insight into the relationship leading to several explanations as to its meaning and contributions to research and practice. This research contributes to IS development knowledge by providing evidence of the essential role of requirements in IS development capabilities and in IS development maturity. Furthermore, contributions to the nascent field of EA research and practice include key insight into EA maturity, EA implementation success, and the role of IT professionals in EA teams. Moreover, these results provide a template and research plan of action to pursue further EA research in exploring EA maturity models and critical success factors, and the state of practice of EA in organizations

On the density of minimal free subflows of general symbolic flows.

Thu, 19 Nov 2009 20:18:23 -0600

This paper studies symbolic dynamical systems {0, 1}G, where G is a countably infinite group, {0, 1}G has the product topology, and G acts on {0, 1}G by shifts. It is proven that for every countably infinite group G the union of the minimal free subflows of {0, 1}G is dense. In fact, a stronger result is obtained which states that if G is a countably infinite group and U is an open subset of {0, 1}G, then there is a collection of size continuum consisting of pairwise disjoint minimal free subflows intersecting U.

Rete Mirabile: An Installation

Thu, 19 Nov 2009 20:18:22 -0600

Rete Mirabile is my new installation piece combining scientific principles with live computer generated music. The title is a Latin term meaning "Wonderful Net," which I use to refer to the highly convoluted network of biological data that drives my installation. The sonification of data, computer modeling of biological processes, kinetic sculptures, and user interactivity are central parts of the installation. The paper is organized as follows: First, brief history of the forerunners that inspired my work is given. This includes a short discussion on how John Cage and David Tudor influenced current artists works, and how those works have influenced my own work. Then I review current installation works that share similarities with my own. Finally, a detailed discussion and analysis of the construction and function concludes the paper.

Links among perceived service quality, patient satisfaction and behavioral intentions in the urgent care industry: Empirical evidence from college students.

Thu, 19 Nov 2009 20:18:22 -0600

Patient perceptions of health care quality are critical to a health care service provider's long-term success because of the significant influence perceptions have on customer satisfaction and consequently organization financial performance. Patient satisfaction affects not only the outcome of the health care process such as patient compliance with physician advice and treatment, but also patient retention and favorable word-of-mouth. Accordingly, it is a critical strategy for health care organizations to provide quality service and address patient satisfaction. The urgent care (UC) industry is an integral part of the health care system in the United States that has been experiencing a rapid growth. UC provides a wide range of medical services for a large group of patients and now serves an increasing population. UC is becoming popular because of the convenient locations, extended hours, walk-in policy, short waiting times, and accessibility. A closer examination of the current health care research, however, indicates that there is a paucity of research on urgent care providers. Confronted with the emergence of the urgent care industry and the increasing demand for urgent care, it is necessary to understand how patients perceive urgent care providers and what influences patient satisfaction and retention. This dissertation addresses four areas relevant to the above mentioned issues: (1) development of an instrument to measure perceived service quality in the urgent care industry; (2) identification of the determinants of patient satisfaction and behavioral intentions; (3) empirical examination of the relationships among perceived service quality, patient satisfaction and behavioral intentions; and (4) comparison of the perceived service quality across several primary urgent care providers, such as urgent care centers, hospital emergency departments, and primary care physicians' offices. To validate this new instrument and examine the hypothesized relationships proposed in this study, an electronic web based survey was designed and administered to college students. Both exploratory and confirmatory factor analysis were employed to assess the reliability and validity of the developed instrument. The contextualized relationships were evaluated using structural equation modeling. The results of this research could potentially contribute to urgent care management and quality improvement.

A Verilog 8051 Soft Core for FPGA Applications

Thu, 19 Nov 2009 20:18:21 -0600

The objective of this thesis was to develop an 8051 microcontroller soft core in the Verilog hardware description language (HDL). Each functional unit of the 8051 microcontroller was developed as a separate module, and tested for functionality using the open-source VHDL Dalton model as benchmark. These modules were then integrated to operate as concurrent processes in the 8051 soft core. The Verilog 8051 soft core was then synthesized in Quartus® II simulation and synthesis environment (Altera Corp., San Jose, CA, www.altera.com) and yielded the expected behavioral response to test programs written in 8051 assembler residing in the v8051 ROM. The design can operate at speeds up to 41 MHz and used only 16% of the FPGA fabric, thus allowing complex systems to be designed on a single chip. Further research and development can be performed on v8051 to enhance performance and functionality.

Finding the perfect blend: A comparative study of online, face-to-face, and blended instruction.

Thu, 19 Nov 2009 20:18:20 -0600

As distance learning evolved, course designers and teachers quickly recognized the value of integrating online features into the classroom. The result was blended learning, a combination of online and face-to-face components. This complex and dynamic new form of education has raised many questions about the role of computer-mediated communication in education and has provided new opportunities for extending research in learning and communication. The purpose of the study was to determine whether a blended class will produce different (and possibly better) results in terms of student perceptions of the overall learning experience and student satisfaction than traditional lecture-based face-to-face instruction or learning that is delivered entirely online. The main goals of this study were to compare the effectiveness of face-to-face, online, and blended instruction, and to examine the role of interactions in the effectiveness of each educational method. While each form of instruction received very positive feedback from both students and instructors and the newly introduced blended courses proved very successful in terms of overall satisfaction with the learning experience, the traditional lecture-based courses produced more positive attitudes toward the subject matter. The possible causes of these discrepancies between some of the quantitative and qualitative results point toward the role of previous experience with online learning, cognitive development, and learning styles.

Effects of triclosan, triclocarban, and caffeine exposure on the development of amphibian larvae.

Thu, 19 Nov 2009 20:18:20 -0600

Triclosan and triclocarban are antimicrobials found in numerous consumer products, while caffeine is the most commonly consumed stimulant by humans. This study was undertaken to determine the effects of triclosan, triclocarban, and caffeine on the development and physiology of amphibian larvae. LC50 values of triclosan and triclocarban were determined after 96 hours for three North American larval species: Acris crepitans blanchardii, Bufo woodhousii woodhousii, Rana sphenocephala, and for a common amphibian developmental model: Xenopus laevis. Amphibian larvae were most sensitive to triclosan and triclocarban exposure during early development based upon 96-hour LC50 values. Heart rates for X. laevis and North American larvae exposed to triclosan were variable throughout development. However, significantly lower heart rates were observed in all larvae exposed to triclocarban. Metabolic rates of X. laevis and R. sphenocephala larvae exposed to triclosan were significantly affected in larvae exposed to ½ LC50 and the LC50 concentration. Metabolic rates of X. laevis larvae exposed to triclocarban were significantly affected by exposure to ½ LC50 concentrations in three of four stages investigated. No significant differences were observed in North American larvae exposed to triclocarban. Tissue uptake, lipid uptake, tissue bioconcentration factor (BCF) and lipid BCF of triclosan and triclocarban were investigated in three developmental stages of X. laevis, and in one developmental stage of B. woodhousii woodhousii, and R. sphenocephala. For most tissue and lipid uptake values, a significant increase was observed as exposure concentration increased. Tissue and lipid BCF values were dependent upon both stage and species. Chronic and acute effects of caffeine were determined in X. laevis larvae. Acute 96-hour LC50 values in four developmental stages were > 75,000 ug L-1 caffeine and heart rates were significantly different at the two earliest developmental stages. Larvae chronically exposed to caffeine reached metamorphosis at the same time as controls. Changes in chronic heart rate were dependent upon stage of development and exposure concentration. This research indicates that the toxicity of amphibian larvae exposed to triclosan, triclocarban, and caffeine appears to be dependent upon species and developmental stage, with early developmental stages being most sensitive to contaminant exposure.

Computational Epidemiology - Analyzing Exposure Risk: A Deterministic, Agent-Based Approach

Thu, 19 Nov 2009 20:18:20 -0600

Many infectious diseases are spread through interactions between susceptible and infectious individuals. Keeping track of where each exposure to the disease took place, when it took place, and which individuals were involved in the exposure can give public health officials important information that they may use to formulate their interventions. Further, knowing which individuals in the population are at the highest risk of becoming infected with the disease may prove to be a useful tool for public health officials trying to curtail the spread of the disease. Epidemiological models are needed to allow epidemiologists to study the population dynamics of transmission of infectious agents and the potential impact of infectious disease control programs. While many agent-based computational epidemiological models exist in the literature, they focus on the spread of disease rather than exposure risk. These models are designed to simulate very large populations, representing individuals as agents, and using random experiments and probabilities in an attempt to more realistically guide the course of the modeled disease outbreak. The work presented in this thesis focuses on tracking exposure risk to chickenpox in an elementary school setting. This setting is chosen due to the high level of detailed information realistically available to school administrators regarding individuals' schedules and movements. Using an agent-based approach, contacts between individuals are tracked and analyzed with respect to both individuals and locations. The results are then analyzed using a combination of tools from computer science and geographic information science.

Making Sense of Teaching: A Holistic Approach to Teacher Reflection about Practice

Thu, 19 Nov 2009 20:18:18 -0600

The purpose of this study was to examine the lived experience of reflection and document how a holistic approach to teacher reflection contributes to teachers' understanding of, and improvement in their pedagogical practice. The investigation asked how classroom observations, when followed by a reflective dialogue, impact pedagogical practice. The particular focus included how teachers make sense of observational data during a post-observation, reflective dialogue; how teachers reflect on classroom observational data; and how the holistic reflection experience impacts teachers' pedagogical practice. Three research questions guided this study. How do teachers make sense of observational data during a post observation reflective dialogue? How do teachers reflect on classroom observational data? How might the holistic reflection experience impact teachers' pedagogical practice? Findings from this study provide implications for incorporating the practice of teacher reflection and reflective dialogue as professional development and for educational research.

Selected works for solo frame drums by B. Michael Williams.

Thu, 19 Nov 2009 20:18:18 -0600

In 1993, American percussionist and composer B. Michael Williams published Four Solos for Frame Drums. This collection is considered the first work written exclusively for solo frame drum in Western notation. Williams primarily modeled his solos around traditional rhythms and techniques from Middle Eastern musical traditions as well as Glen Velez's virtuosic style of playing frame drums. He also drew influence from the music of South India and Sub-Saharan Africa. Williams intentionally combines the aforementioned elements as a means to expose his students and audience members to the music and drumming of these regions. The purpose of this paper is to provide a detailed analysis of select compositions for solo frame drum by B. Michael Williams in order to assist future performers in making well-informed interpretive decisions. The analysis will highlight the compositional style, structural components, technical demands and important performance considerations of four pieces by Williams: Quatrinity, Etude in Arabic Rhythms, Another New Riq and Rhythmic Journey no. 1: (From Conakry to Harare).

Cathedral of Hope: A History of Progressive Christianity, Civil Rights, and Gay Social Activism in Dallas, Texas, 1965 - 1992

Thu, 19 Nov 2009 20:18:18 -0600

This abstract is for the thesis on the Cathedral of Hope (CoH). The CoH is currently the largest church in the world with a predominantly gay and lesbian congregation. This work tells the history of the church which is located in Dallas, Texas. The thesis employs over 48 sources to help tell the church's rich history which includes a progressive Christian philosophy, an important contribution to the fight for gay civil rights, and fine examples of courage through social activism. This work makes a contribution to gay history as well as civil rights history. It also adds to the cultural and social history which concentrates on the South and Southwestern regions of the United States.