Ecotoxicological Investigations in Effluent-Dominated Stream Mesocosms (open access)

Ecotoxicological Investigations in Effluent-Dominated Stream Mesocosms

The University of North Texas Stream Research Facility (UNTSRF) was designed to examine contaminant impacts on effluent-dominated stream ecosystems. Stream mesocosms, fed municipal effluent from the City of Denton, TX, Pecan Creek Water Reclamation Plant (PCWRP), were treated with 0, 15 or 140 µg/L cadmium for a 10-day study in August 2000. Laboratory toxicity test and stream macroinvertebrate responses indicated that cadmium bioavailability was reduced by constituents of effluent-dominated streams. The Biotic Ligand Model (BLM) for Cd was used to predict a 48 hour Cd EC50 for Ceriodaphnia dubia of 280 µg/L in these effluent-dominated streams. This value is higher that an EC50 of 38.3 µg/L Cd and a 7-day reproduction effect level of 3.3 µg/L Cd generated for C. dubia in reconstituted laboratory hard water. These results support use of a cadmium BLM for establishing site-specific acute water quality criteria in effluent-dominated streams. Although not affected by 15 µg/L treatments, organisms accumulated Cd in 15 µg/L treated streams. Hence, over longer exposure periods, Cd accumulation may increase and a no effect level may be lower than the observed 10-day no effect level of 15 µg/L. A toxicity identification evaluation procedure was utilized with in vitro and in vivo bioassays …
Date: December 2002
Creator: Brooks, Bryan W.
System: The UNT Digital Library

The Solo Compositions for Trumpet of Fisher Aubrey Tull: An Analysis of Structural, Technical, and Stylistic Elements for Performance Preparation, with Three Recitals of Selected Works by Bozza, Fasch, Haydn, Tomasi, and Others

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The compositions of Fisher Aubrey Tull are widely performed and many have become standard repertoire. Tull's compositions encompass a multiplicity of performance media including works for orchestra, chorus, symphonic band, jazz band, brass choir, and solo and chamber works. Tull's compositional output for the trumpet is prolific and is acknowledged to be music of high quality. An examination of Trumpet and Brass Programs, compiled and published annually by the International Trumpet Guild, shows Tull's solo and ensemble works for trumpet to be frequently performed. Furthermore, his compositions for trumpet have been performed and recorded by internationally acclaimed artists including Vincent DiMartino, Terry Everson, Håkan Hardenberger, Anthony Plog, Carl "Doc" Severinsen and Allen Vizzutti.This study investigates Fisher Tull's eight solo works for trumpet, which include: Vignette for Trumpet and Piano (1954); Concerto No. 1 for Trumpet and Orchestra (1964); Concerto No. 2 for Trumpet and Band (1974); Three Bagatelles for Trumpet and Piano (1975); Eight Profiles for Solo Trumpet (1978); Rhapsody for Trumpet and Band (1980); Sonata for Trumpet and Piano (1986); and Chromutations for Solo Trumpet (1988). Histories of each composition are chronicled. An analysis of formal organization and significant style features examines musical structure, harmonic language, rhythmic character, instrumentation, …
Date: August 2002
Creator: Wenger, Alan J.
System: The UNT Digital Library
An Assessment of the Parent Orientation Program at the University of North Texas (open access)

An Assessment of the Parent Orientation Program at the University of North Texas

Although most institutions offer a parent program option to the orientation program, there has been little formalized research into the quality, planning or programming of parent orientation. There has been very little research into the impact parent orientation has on parents and whether or not they feel that such programs have met their needs, particularly by gender, minority status, educational background, or by geographic distance from the institution. This study seeks to determine the effectiveness of the parent orientation program at the University of North Texas to the parents who participate in this program. The study attempts to measure whether parents feel that they have adequate information about the institution to adequately support their student through the college transition; if parents feel welcomed by the UNT campus community; and if they feel that they have developed resources and institutional contacts that may be useful in the future in assisting their child to have a successful college experience at UNT. The study, conducted in the summer of 2002, had 736 respondents. An instrument developed to determine parent's perceptions of the effectiveness of the parent orientation program consisted of 31 questions using a Likert scale. A t-Test was utilized to analyze the …
Date: December 2002
Creator: With, Elizabeth
System: The UNT Digital Library
Dna Profiling of Captive Roseate Spoonbill (Ajaia Ajaja) Populations As a Mechanism of Determining Lineage in Colonial Nesting Birds. (open access)

Dna Profiling of Captive Roseate Spoonbill (Ajaia Ajaja) Populations As a Mechanism of Determining Lineage in Colonial Nesting Birds.

Roseate spoonbills are colonial nesting birds with breeding grounds extending from the United States Gulf coast to the pampas of Argentina. The U.S. population suffered a severe bottleneck from 1890 to 1920. The population's recovery was slow and partially credited to migrations from Mexican rookeries, but a gene pool reduction would be expected. Five polymorphic Spoonbill autosomal short tandem repeat (STR) loci [three (GAT)n, one (AAAG)n and one (GT)n] and one Z/W-linked microsatellite exhibiting sex-specific dimorphism were isolated and characterized. The Z/W-linked STR locus accurately confirmed the sex of each bird. Allelic profiles for 51 spoonbills obtained from Dallas (Texas), Fort Worth (Texas) and Sedgwick County (Kansas) zoos revealed a non-continuous distribution of allele frequencies, consistent with the effects of a population bottleneck. Allelic frequencies also differed significantly between the isolated zoo populations. Although extra-pair copulations were suspected and difficult to document, zoos commonly used observational studies of mating pairs to determine familial relationships among adults and offspring. STR parentage analysis of recorded family relationships excluded one or both parents in 10/25 cases studied and it was further possible to identify alternative likely parents in each case. Mistaken familial relationships quickly lead to the loss of genetic variability in captive …
Date: May 2002
Creator: Sawyer, Gregory M.
System: The UNT Digital Library

Peter Lieberson's First Piano Concerto: A Buddhist-inspired poetic vision realized through twelve-tone language, other contemporary compositional techniques, together with three recitals of works by Bach, Chopin, Mozart, Albéniz, Grieg, Ginastera and Paderecki

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The main objective of this document is to explore the life and spiritual convictions of composer Peter Lieberson, and the creation of his Piano Concerto. Lieberson is a sought after composer who has won many awards and commissions. His works have been premiered and performed by some of the best musical artists of the late twentieth- and early twenty-first-century, such as Peter Serkin, Emmanuel Ax, Yo-Yo Ma, and Pierre Boulez. This study is divided into six chapters. After the Introduction, a biographical summary of Peter Lieberson's life, his spiritual beliefs and compositional style is presented. Chapter II contains background information on the Piano Concerto, along with biographical sketches of Peter Serkin, for whom the work was written, and Seiji Ozawa, music director of the Boston Symphony Orchestra and conductor of both the premier performance and Serkin's recording of the piece. Chapter III is a selective survey of the compositional techniques used in Lieberson's Concerto, in terms of the application of twelve-tone theory and the resulting octatonic, pentatonic, and whole-tone scales. Chapter IV introduces a general overview of the influence of Buddhism as a source of inspiration in the Piano Concerto. Chapter V examines aspects of performance practice issues. Chapter VI …
Date: August 2002
Creator: Méndez-Flanigan, Maria Gisela
System: The UNT Digital Library
Working Whiteness: Performing And Transgressing Cultural Identity Through Work (open access)

Working Whiteness: Performing And Transgressing Cultural Identity Through Work

Early in Richard Wright's Native Son, we see Bigger and his friend Gus “playing white.” Taking on the role of “J. P. Morgan,” the two young black men give orders and act powerful, thus performing their perceived role of whiteness. This scene is more than an ironic comment on the characters' distance from the lifestyle of the J. P. Morgans of the world; their acts of whiteness are a representation of how whiteness is constructed. Such an analysis is similar to my own focus in this dissertation. I argue that whiteness is a culturally constructed identity and that work serves as a performative space for defining and transgressing whiteness. To this end, I examine work and its influence on the performance of middle class and working class whiteness, as well as how those outside the definitions of whiteness attempt to “play white,” as Bigger does. Work enables me to explore the codes of whiteness and how they are performed, understood, and transgressed by providing a locus of cultural performance. Furthermore, by looking at novels written in the early twentieth century, I am able to analyze characters at a historical moment in which work was of great import. With the labor …
Date: May 2002
Creator: Polizzi, Allessandria
System: The UNT Digital Library

The relationship between training in learning style adaptation and successful completion of entry-level community college classes.

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The purpose of this study was to determine if there was a relationship between training in learning style adaptation and successful completion of community college courses. The rationale for conducting this study was based on the need for students to learn how to adapt their learning style in order to more effectively learn in any situation. It is also important that community colleges implement strategies that assist in student retention. The learning styles of entry-level community college students were measured using Kolb's Learning Style Inventory Version 3. Students enrolled in entry-level college courses at a small North Texas community college were studied. The Chi-square Test of Independence with a 2 x 2 design was employed. Findings indicated that there was no statistically significant difference in the relationship between students receiving training in learning styles adaptation and successful completion of entry-level college courses, and that students who attended a learning styles training session and those who did not attend a learning styles training session had an equal chance of succeeding in entry-level community college courses. Findings also indicated that students with Accommodating and Assimilating learning styles are less likely to successfully complete an entry-level college course than are students with Diverging …
Date: December 2002
Creator: Ferrell, Dawn M.
System: The UNT Digital Library
An Investigation into Motivations of Instructors Teaching Business and Technical Internet-Based Courses at Two-Year Colleges (open access)

An Investigation into Motivations of Instructors Teaching Business and Technical Internet-Based Courses at Two-Year Colleges

This research was conducted to determine why two-year community college instructors teach over the Internet. By understanding why these instructors teach over the Internet, colleges can recruit more instructors to teach using the Web thus allowing colleges to offer more Internet courses. They can also use the information to keep the instructors who are currently teaching over the Internet satisfied, and motivate them to continue to teach. To gather this information, a questionnaire was created and evaluated for reliability and validity during a pilot study. It was then sent to those instructors who taught over the Internet, and had their e-mails available on their campus Website. A 30.5% response rate (N=100) was achieved. The survey was divided into two sections, a demographics section and a Likert scale dealing with motivation. The Likert scale had six choices ranging from strongly agree to strongly disagree and 31 statements. The demographic data were reported and summarized. The Likert items were examined using factor analysis techniques, and a number of components were discovered. Eight components, made up of the 31 variables from the Likert scale were found using the factor analysis. The eight components in order are labeled: Technical and Computer Challenges, School Promotion, …
Date: December 2002
Creator: Swartwout, Nansi. A.
System: The UNT Digital Library

The Crater of Diamonds: A History of the Pike County, Arkansas, Diamond Field, 1906-1972

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The first diamond mine in North America was discovered in 1906 when John W. Huddleston found two diamonds on his farm just south of Murfreesboro in Pike County, Arkansas. Experts soon confirmed that the diamond-bearing formation on which Huddleston made his discovery was the second largest of its kind and represented 25 percent of all known diamond-bearing areas in the world. Discovery of the field generated nearly a half century of speculative activity by men trying to demonstrate and exploit its commercial viability. The field, however, lacked the necessary richness for successful commercial ventures, and mining was eventually replaced in the early 1950s by tourist attractions that operated successfully until 1972. At that time the State of Arkansas purchased the field and converted it to a state park. Thus this work tell the rich and complicated story of America'a once and only diamond field, analyzes the reasons for the repeated failures of efforts to make it commercially viable, and explains how it eventually succeeded as a tourist venture.
Date: May 2002
Creator: Henderson, John C.
System: The UNT Digital Library
Students' and Teachers' Perceptions of Culturally Responsive Teaching: A Case Study of an Urban Middle School (open access)

Students' and Teachers' Perceptions of Culturally Responsive Teaching: A Case Study of an Urban Middle School

This was a qualitative study that used the procedures of case study design while incorporating ethnographic techniques of interviewing and non-participant observation in classrooms with six selected students, six teachers, and eight interviews of selected administrators and staff members in one middle school in a large Texas urban school district. The purpose of this study was to understand the educational experiences and perceptions of selected immigrant students and their mainstream teachers. Following the method of case study design, the educational experiences of English Language Learner (ELL) students were examined in the naturally occurring context of the school and the classroom. Because the goal of case studies is to understand a given phenomenon from the perceptions of the participants (referred to as “emic” perspective) all participants were interviewed in-depth in order to understand their unique perceptions. The study took place during a five-month period in the spring of 2002. Data were analyzed concurrently during data collection and were framed by Geneva Gay's (2000) characteristics of culturally responsive teaching. The findings and interpretation of data are divided into three parts that encompass the results of the five research questions that guided this study. Part one presents the teachers' perceptions and addresses the …
Date: December 2002
Creator: Curtin, Ellen Mary
System: The UNT Digital Library

The Impact of Drug Testing on Secondary School Students

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The purpose of this study determined whether use of student random drug testing provided an effective means to reduce drug usage by secondary school students. The participants included 50,214 7th through 12th grade students in 12 selected public schools. All school districts participated in the Texas School Survey of Substance Use in 1994, 1996, 1998, and 2000. The six districts in the experimental group used drug testing as a method of reducing drug usage among students. The six districts in the control group did not use drug testing. Although athletes and students involved in extracurricular activities remain the focus of random dug testing, this research focused on an entire school population to determine whether drug testing only a select group of students reduced reported drug usage in the entire school. Two questions guided the research: First, does the use of random drug testing have an impact on student drug usage? Second, does the year of implementation of random drug testing have an impact on students' self-reported drug usage? The findings for each research question were categorized according to nine illegal drugs. The researcher used a one-way repeated measures factorial design. The data were analyzed via the univariate (split-plot) 2 x …
Date: December 2002
Creator: Lee, Elton David
System: The UNT Digital Library

Layered Double Hydroxides: Morphology, Interlayer Anion, and the Origins of Life

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The preparation of layered double hydroxides via co-precipitation of a divalent/trivalent metal solution against a base results in 1 mm LDH particles with a disorganized metal lattice. Research was performed to address these morphological issues using techniques such as Ostwald ripening and precipitation via aluminate. Another interesting issue in layered double hydroxide materials is the uptake and orientation of anions into the interlayer. Questions about iron cyanide interlayer anions have been posed. Fourier transform infared spectroscopy and powder x-ray diffraction have been used to investigate these topics. It was found that factors such as orientation, anion charge, and anion structure depended on the divalent/trivalent metal ratio of the hydroxide layer and reactivity time. The cyanide self-addition reaction is an important reaction of classical prebiotic chemistry. This reaction has been shown to give rise to amino acids, purines and pyrimidines. At cyanide concentrations similar to that expected on the early earth, hydrolysis to formamide rather than self-addition occurs. One theory to alleviate this side reaction is the use of minerals or clays that are thought to concentrate and catalyze prebiotics of interest. Layered double hydroxides have been studied as a catalyst for this reaction.
Date: December 2002
Creator: Halcom-Yarberry, Faith Marie
System: The UNT Digital Library
The influence of klezmer on twentieth-century solo and chamber concert music for clarinet: with three recitals of selected works of Manevich, Debussy, Horovitz, Milhaud, Martino, Mozart and others. (open access)

The influence of klezmer on twentieth-century solo and chamber concert music for clarinet: with three recitals of selected works of Manevich, Debussy, Horovitz, Milhaud, Martino, Mozart and others.

The secular music of the Eastern European Jews is known today as klezmer. Klezmer was the traditional instrumental celebratory music of Yiddish-speaking Ashkenazi Jews who eventually populated the Pale of Settlement, which encompassed modern-day Poland, Lithuania, Ukraine, Belarus and Romania. Due to the rise of oppression and expulsion, many klezmer musicians or klezmorim immigrated to the United States between 1880 and the early 1920s. These musicians found work in klezmer bands and orchestras as well as Yiddish radio and theater. Some of the most influential klezmorim were clarinetists Naftule Brandwein and Dave Tarras who helped develop an American klezmer style. While the American style flourished, the popularity of pure klezmer began to diminish. As American-born Jews began to prefer the new sounds of big band and jazz, klezmer was considered old-fashioned and was in danger of becoming a lost art form. During the early 1970s, a reawakening study of klezmer developed. Henry Sapoznik, Lev Liberman and Andy Statman were instrumental in creating a klezmer revival in the United States. At the same time, Argentinean-born Israeli clarinetist Giora Feidman was popularizing klezmer in Europe. Klezmer had again become popular and the revival's impact on the concert hall was inevitable. Even though …
Date: December 2002
Creator: Card, Patricia Pierce
System: The UNT Digital Library

Attrition Rates of Teachers Trained in Alternative Teacher Certification Programs, Those Trained in the Centers for the Professional Development of Teachers, and Those Trained in Traditional University Programs.

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This study uses teacher employment data provided by the State Board for Educator Certification to examine the similarities and differences between initial employment and attrition rates of teachers trained in three prevalent types of Texas teacher preparation programs; alternative certification programs (ACP), the centers for professional development of teachers (CPDT), and traditional certification programs (TCP). The population for the study includes all Texas teachers who completed training in these programs in 1995, 1996, and 1997. The study found that ACP participants gain employment as Texas public school teachers at a significantly higher rate than their CPDT and TCP trained peers in year-one after completion of their training. However, ACP completers experience higher attrition rates in each of the subsequent years investigated. The study concludes that the overall cumulative attrition rate of new teachers trained in these programs is not as pronounced as originally presumed, but that low production levels cannot keep up with the growing demand for new teachers. Teacher preparation program leaders must seek ways to recruit and train more teachers.
Date: May 2002
Creator: Harris, Steven A.
System: The UNT Digital Library

Removal of selected water disinfection byproducts, and MTBE in batch and continuous flow systems using alternative sorbents.

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A study was conducted to evaluate the sorption characteristics of six disinfection byproducts (DBPs) on four sorbents. To investigate sorption of volatile organic compounds (VOCs), specially designed experimental batch and continuous flow modules were developed. The investigated compounds included: chloroform, 1,2-dichloroethane (DCE), trichloroethylene (TCE), bromodichloromethane (BDCM), methyl tertiary butyl ether (MTBE), bromate and bromide ions. Sorbents used included light weight aggregate (LWA), an inorganic porous material with unique surface characteristics, Amberlite® XAD-16, a weakly basic anion exchange resin, Amberjet®, a strongly basic anion exchange resin, and granular activated carbon (GAC). Batch experiments were conducted on spiked Milli-Q® and lake water matrices. Results indicate considerable sorption of TCE (68.9%), slight sorption of bromate ions (19%) and no appreciable sorption for the other test compounds on LWA. The sorption of TCE increased to 75.3% in experiments utilizing smaller LWA particle size. LWA could be a viable medium for removal of TCE from contaminated surface or groundwater sites. Amberlite® was found unsuitable for use due to its physical characteristics, and its inability to efficiently remove any of the test compounds. Amberjet® showed an excellent ability to remove the inorganic anions (>99%), and BDCM (96.9%) from aqueous solutions but with considerable elevation of pH. …
Date: December 2002
Creator: Kadry, Ahmed Y.
System: The UNT Digital Library
Improving the Definition of Exercise Maintenance: Evaluation of Concepts Related to Adherence (open access)

Improving the Definition of Exercise Maintenance: Evaluation of Concepts Related to Adherence

Physical activity has been demonstrated in the literature as an effective way to reduce the risk for development of chronic disease. The Transtheoretical Model (TTM) of behavior change has been developed as a means to predict and facilitate movement into healthier lifestyle behaviors. The model is centered on "stages of change", which describe a continuum of readiness to engage in a health behavior change. Stages contain temporal, qualitative, and quantitative characteristics. This was a six-month study that evaluated the effectiveness of stage-matched (theorized to be pertaining only to the maintenance stage of change) vs. generic (theorized to be pertaining to anyone, regardless of stage) newsletters in assisting subjects to attain the Maintenance stage of change. It also sought to identify further qualitative characteristics that can differentiate between the Action and Maintenance stages of change. Results indicated that monthly stage-matched newsletters were no more effective in helping subjects reaching Maintenance than were the generic newsletters. Exerciser self-schema was related to stages of change, but those relationships differed from baseline to six-month follow-up, indicating development of exerciser self-schema during the study period. Implications of this are discussed. Other concepts discussed included "structure" of change process, in that three new scores were developed …
Date: August 2002
Creator: Wilcox, Susan E.
System: The UNT Digital Library
Investigation of Lead Hydrolytic Polymerization and Interactions with Organic Ligands in the Soil/Sediment-Water Environment (open access)

Investigation of Lead Hydrolytic Polymerization and Interactions with Organic Ligands in the Soil/Sediment-Water Environment

The objective of this research was to investigate lead speciation in the soil/sediment-water environment and to better understand how the species affect lead mobility under different environmental conditions. The research involved both field soil and sediment samples as well as standard lead solutions. Field samples were fully characterized and extracted by aqueous and organic solvents. The results were compared and evaluated with the metal speciation model, MINTEQA2. Hydrolytic polymerization and organic complexation studies were conducted with standard lead solutions under controlled experimental conditions. Results of the field samples showed that pH, dissolved cations, ionic strength, dissolved organic matter, and nature of the soil/sediment matrix play major roles in the distribution and mobility of lead (Pb) from contaminated sites. In the aqueous equilibration experiment, the magnitude of Pb2+ solubilization was in the order of pH4>pH7>pH9. The results were in good agreement with MINTEQA2 predictions. An important finding of the research is the detection of Pb polymerization species under controlled experimental conditions. At pH 5.22, Pb polymeric species were formed at rate of 0.03 per day. The role of Pb complexation with organic matter was evaluated in both field and standard samples. Different methodologies showed three types of organically bound Pb. A …
Date: December 2002
Creator: Sanmanee, Natdhera
System: The UNT Digital Library