Degree Level

Model for Long-range Correlations in DNA Sequences (open access)

Model for Long-range Correlations in DNA Sequences

We address the problem of the DNA sequences developing a "dynamical" method based on the assumption that the statistical properties of DNA paths are determined by the joint action of two processes, one deterministic, with long-range correlations, and the other random and delta correlated. The generator of the deterministic evolution is a nonlinear map, belonging to a class of maps recently tailored to mimic the processes of weak chaos responsible for the birth of anomalous diffusion. It is assumed that the deterministic process corresponds to unknown biological rules which determine the DNA path, whereas the noise mimics the influence of an infinite-dimensional environment on the biological process under study. We prove that the resulting diffusion process, if the effect of the random process is neglected, is an a-stable Levy process with 1 < a < 2. We also show that, if the diffusion process is determined by the joint action of the deterministic and the random process, the correlation effects of the "deterministic dynamics" are cancelled on the short-range scale, but show up in the long-range one. We denote our prescription to generate statistical sequences as the Copying Mistake Map (CMM). We carry out our analysis of several DNA sequences, …
Date: December 1996
Creator: Allegrini, Paolo
System: The UNT Digital Library
An Application of Marxian and Weberian Theories of Capitalism: the Emergence of Big Businesses in the United States, 1861 to 1890 (open access)

An Application of Marxian and Weberian Theories of Capitalism: the Emergence of Big Businesses in the United States, 1861 to 1890

This study was an examination of businesses that became big businesses in the United States during the time period between the years of 1861 and 1890, a period of time frequently referred to as the “big business era.” The purpose of the study was to identify actions taken by businesses that enabled them to become and remain big businesses. A secondary purpose of the study was to show that these actions were explained by theories of Karl Marx and Max Weber. The results of the study showed that businesses which took specific actions were able to become and remain big businesses and these actions were explained by the theories of Marx and Weber. The results of the study demonstrate the ability of classical sociological theory to explain macro-level social change.
Date: May 2015
Creator: Magness, Penny J.
System: The UNT Digital Library
Relationship between Adolescents' Perceptions of Parental Physical Activity and Their Own Well-Being (open access)

Relationship between Adolescents' Perceptions of Parental Physical Activity and Their Own Well-Being

The purpose of this study was to examine the relationship between adolescents' perceptions of their parents' encouragement to lose weight and physical activity habits (i.e., exercise habits and sedentary behaviors) and their own physical health-related fitness (HRF) and psychological well-being. Results of structural equation modeling revealed both similarities and differences between boys and girls. Specifically, parental sedentary behavior and encouragement to lose weight related to girls HRF. Among boys, only encouragement to lose weight related to HRF. When inspecting the relationship between HRF and psychological well-being, HRF related to body satisfaction, but not depressive symptoms, among both boys and girls. Results of this study highlight the complex influence that parental perceptions have during adolescent development.
Date: August 2017
Creator: Yeatts, Paul E.
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
Epistemological, Ontological, and Ethical Dimensions of Biocultural Rights: The Case of the Atrato River, Colombia (open access)

Epistemological, Ontological, and Ethical Dimensions of Biocultural Rights: The Case of the Atrato River, Colombia

In 2016, the Colombian Constitutional Court recognized the Atrato River as a subject of rights based on the theory of biocultural rights. This dissertation analyzes a new legal concept that aims to defend the rights to a good life for humans and other-than-human co-inhabitants who share river ecosystems, focusing on the case of the Atrato River in Colombia. The 3Hs framework of biocultural ethics is adopted to interconnect complex and interrelated historical, biophysical, cultural, and political dimensions. With this analysis, broader biocultural approaches are suggested. They could be valuable for understanding and implementing biocultural rights in other world regions. Moreover, it could transform the current situation that destroys biocultural diversity toward public policies that favor more just and sustainable forms of co-inhabiting biocultural diversity. A primary limitation of the implementation of biocultural rights is the context of a "failed state," in which the Colombian State is subject to severe problems of corruption, illegal mining, conflicts between legal and illegal armed groups, and drug trafficking. There is a need for a dialogue solution to the conflict. This requires that illegal armed groups are valued as co-inhabitants. Achieving social-environmental justice is essential for biocultural ethics. In this case, it is the condition …
Date: August 2022
Creator: González Morales, Valentina
System: The UNT Digital Library
Impaired virulence factor production in a dihydroorotate dehydrogenase mutant (pyrD) of  Pseudomonas aeruginosa. (open access)

Impaired virulence factor production in a dihydroorotate dehydrogenase mutant (pyrD) of Pseudomonas aeruginosa.

Previous research in our laboratory showed that when knockout mutations were created in the pyrB and pyrC genes of the pyrimidine pathway in Pseudomonas aeruginosa, not only were the resultant mutants auxotrophic for pyrimidines but they were also impaired in virulence factor production. Such a correlation had not been previously reported for P. aeruginosa, a ubiquitous opportunistic pathogen in humans. In an earlier study it was reported that mutants blocked in one of the first three enzymes of the pyrimidine pathway in the non-pathogenic strain P. putida M produced no pyoverdin pigment while mutants blocked in the later steps produced copious amounts of pigment, just like the wild type. This study probed for the same connection between pyrimidine auxotrophy and pigment production applied in P. aeruginosa. To that end a knockout mutation was created in pyrD, the fourth step in the pyrimidine pathway which encodes dihydroorotate dehydrogenase. The resulting mutant required pyrimidines for growth but produced wild type pigment levels. Since the pigment pyoverdin is a siderophore it may also be considered a virulence factor, other virulence factors were quantified in the mutant. These included casein protease, hemolysin, elastase, swimming, swarming and twitching motility, and iron binding capacity. In all …
Date: December 2005
Creator: Ralli, Pooja
System: The UNT Digital Library
Ecology and Recolonization of Benthic Macroinvertebrates in a Groundwater-dependent Stream in North Central Texas During a Supra-seasonal Drought (open access)

Ecology and Recolonization of Benthic Macroinvertebrates in a Groundwater-dependent Stream in North Central Texas During a Supra-seasonal Drought

Extreme climatic events such as droughts are known to eliminate aquatic biota and alter community structure and function. Perennial headwater springs provide important drought refugia to benthic macroinvertebrates and an important source of colonists via drift or aerial adults to intermittent streams post-drought. During a supra-seasonal drought in North-central Texas summer and fall 2006, benthic macroinvertebrates from persistent groundwater-dependent macrohabitats of varying hydrological connectivity and riparian shading were studied: perennial riffles, connected pools, shaded disconnected pools, and full sun disconnected pools. Riffles were a distinct habitat with significantly higher taxa richness, proportion of lotic taxa, diversity and evenness than other macrohabitats. Macrohabitats were found to be important refugia for 106 benthic macroinvertebrates and 4 microcrustacean taxa. Throughout the extreme drought, perennially flowing habitats were refugia to 19 taxa (17.9% total taxa) not collected in disconnected pools. Shaded disconnected pools contained lotic taxa not previously known to be able to complete their lifecycles in lentic habitats, emphasizing the importance of groundwater effluent and shading. With the resumption of flow at a downstream intermittent site of Ash Creek in mid-October 2006, an annual recolonization study was conducted comparing the perennial headwaters’ benthic macroinvertebrate taxa richness, densities and community ecology with the downstream …
Date: May 2012
Creator: Burk, Rosemary A.
System: The UNT Digital Library
Knowledge management in times of change: Tacit and explicit knowledge transfers. (open access)

Knowledge management in times of change: Tacit and explicit knowledge transfers.

This study proposed a look at the importance and challenges of knowledge management in times of great change. In order to understand the information phenomena of interest, impacts on knowledge workers and knowledge documents in times of great organizational change, the study is positioned in a major consolidation of state agencies in Texas. It pays special attention to how the changes were perceived by the knowledge workers by interviewing those that were impacted by the changes resulting from the reorganization. The overall goal is to assess knowledge management in times of great organizational change by analyzing the impact of consolidation on knowledge management in Texas's Health and Human Services agencies. The overarching research question is what happened to the knowledge management structure during this time of great change? The first research question was what was the knowledge worker environment during the time of change? The second research question was what was the knowledge management environment of the agencies during the time of change? The last research question was did consolidation of the HHS agencies diminish the ability to transition from tacit to explicit knowledge? Additionally, the study investigates how the bill that mandated the consolidation was covered in the local …
Date: December 2005
Creator: Hall, Heather Leigh
System: The UNT Digital Library
Livestock Legacy: A History of the Fort Worth Stockyards Company 1893-1982 (open access)

Livestock Legacy: A History of the Fort Worth Stockyards Company 1893-1982

This dissertation outlines the creation and history of the Fort Worth Stockyards Company from its conception to the time of this dissertation's publication. The Fort Worth Stockyards Company was created by Greenleif W. Simpson and Louville V. Niles. This company would soon cement Fort Worth as the premier livestock producer in America, soon surpassing Chicago.
Date: August 1982
Creator: Pate, J'Nell L.
System: The UNT Digital Library
The Development and Management of Human Resources in Iran (open access)

The Development and Management of Human Resources in Iran

The problem with which this study is concerned is that of determining and analyzing the problems of human resources created in Iran. These problems are rooted deeply and stream from Iranian history, culture, and social environment. The main purposes of this study are three. The first is to determine and analyze problems of human resources created in Iran, including social environment, education, and employment. The second is to study and evaluate the manpower policy of Iranian economic development. The third is to apply human resource development in planning, educating, training, and developing the human resources required for the economic development of Iran. Based on the reports and recommendations of the three research groups, a detailed plan and strategies are written to develop Iran's human resources.
Date: May 1979
Creator: Sharifzadeh, Mansour
System: The UNT Digital Library
Storm Water System Monitoring for the Small Municipality Under Phase II of the National Pollutant Discharge Elimination System (open access)

Storm Water System Monitoring for the Small Municipality Under Phase II of the National Pollutant Discharge Elimination System

Storm water quality can have a significant impact on receiving water bodies. The chief recipients of these impacts are aquatic life in the receiving water body and downstream water users. Over the last few decades, legislation, regulations, institutions and facilities have evolved to recognize the impact of urban storm water on receiving streams. This increased emphasis has caused contaminants in storm water to be identified as a major concern. This developing concern has generated an increased interest in the water quality of our streams and lakes and emphasized the need for more monitoring efforts. With the passage of the National Pollutant Discharge Elimination System (NPDES) Phase II requirements, small municipalities are responsible for storm water impacts on receiving waters within their jurisdiction. For the purposes of NPDES Phase II requirements, small municipalities are identified as these municipalities that are typically composed of 10,000 but less than 100,000 in population. The purpose of this dissertation is to develop a manual for use by the staff of small municipalities in meeting the requirements prescribed by changes initiated in the NPDES Phase II regulations. Attempts were made to comply with these requirements within a very limited manpower and budget framework and to develop …
Date: August 2003
Creator: Peacock, Steven
System: The UNT Digital Library
Cattle Capitalists: The XIT Empire in Texas and Montana (open access)

Cattle Capitalists: The XIT Empire in Texas and Montana

The Texas Constitution of 1876 set aside three million acres of Texas public land in exchange for construction of the monumental red granite Capitol that continues to house Texas state government today. The Capitol project and the land went to an Illinois syndicate led by men influential in business and politics. Austin's statehouse is a recognizable symbol of Texas around the world. So too, the massive Panhandle tract given in exchange -- what became the "fabulous" XIT Ranch -- has come to, for many, symbolize Texas and its role in the nineteenth century cattle boom. After finding sales prospects for the land, known as the Capitol Reservation, weak at the time, backed by British capital, the Illinois group, often called the Capitol Syndicate, turned their efforts to cattle ranching to satisfy investors until demand for the land increased. The operation included a satellite ranch in Montana to which two-year-old steers from Texas were sent for fattening, often "over the trail" on a route increasingly blocked by people and settlement. Rather than a study focused on ranching operations on the ground -- the roundups, the cattle drives, the cowboys -- this instead uncovers the business and political side of the Syndicate's …
Date: December 2017
Creator: Miller, Michael M.
System: The UNT Digital Library
Nucleotide Sequence Determination, Subcloning, Expression and Characterization of the xy1LT Region of the Pseudomonas putida TOL Plasmid pDK1 (open access)

Nucleotide Sequence Determination, Subcloning, Expression and Characterization of the xy1LT Region of the Pseudomonas putida TOL Plasmid pDK1

The complete nucleotide sequence of the region encoding the DHCDH function of the pDK1 lower operon was determined. DNA analysis has shown the presence of two open reading frames, one gene consisting of 777 nucleotides encoding a polypeptide of 27.85 kDa and another gene of 303 nucleotides encoding a polypeptide of 11.13 kDa. The results of enzymatic expression studies suggest that DHCDH activity is associated only with xy1L. However although the addition of xy1T cell-free extracts to xy1L cell-free extracts does not produce an increase in DHCDH activity, subclones carrying both xy1L and xy1T exhibit 300- 400% more DHCDH activity than subclones carrying only xy1L.
Date: December 1992
Creator: Baker, Ronald F. (Ronald Fredrick)
System: The UNT Digital Library
Design of Bioinspired Conductive Smart Textile (open access)

Design of Bioinspired Conductive Smart Textile

Electrically conductive fabrics are one of the major components of smart textile that attracts a lot of attention by the energy, medical, sports and military industry. The principal contributors to the conductivity of the smart textiles are the intrinsic properties of the fiber, functionalization by the addition of conductive particles and the architecture of fibers. In this study, intrinsic properties of non-woven carbon fabric derived from a novel linear lignin, poly-(caffeyl alcohol) (PCFA) discovered in the seeds of the vanilla orchid (Vanilla planifolia) was investigated. In contrast to all known lignins which comprise of polyaromatic networks, the PCFA lignin is a linear polymer. The non-woven fabric was prepared using electrospinning technique, which follows by stabilization and carbonization steps. Results from Raman spectroscopy indicate higher graphitic structure for PCFA carbon as compared to the Kraft lignin, as seen from G/D ratios of 1.92 vs 1.15 which was supported by a high percentage of graphitic (C-C) bond observed from X-ray photoelectron spectroscopy (XPS). Moreover, from the XRD and TEM a larger crystal size (Lc=12.2 nm) for the PCFA fiber was obtained which correlates to the higher modulus and conductivity of the fiber. These plant-sourced carbon fabrics have a valuable impact on zero …
Date: August 2017
Creator: Rizvi, Syed Hussain Raza
System: The UNT Digital Library
Resistance Exercise and Alcohol: Combined Effects on Physiology and Performance (open access)

Resistance Exercise and Alcohol: Combined Effects on Physiology and Performance

Resistance exercise (RE) training is a well-known and effective method for promoting increases in muscle mass and strength. A single bout of RE induces physiological disturbances that require coordinated activation of the immune system and intramuscular signaling in order to return the tissue to homeostasis and adapt to the RE challenge. On the other hand, acute binge alcohol consumption can affect the immune response to an inflammatory challenge, intramuscular anabolic signaling, and muscle protein synthesis, and the effects of alcohol on these processes are opposite that of RE. Furthermore, individuals who report more frequent exercise also report a greater frequency of binge drinking. However, few investigations exist regarding the effects of binge alcohol consumed after a bout of RE on RE-induced physiological changes and performance recovery. Therefore, the overarching purpose of the investigations contained within this dissertation was to investigate the effect of alcohol consumed after RE on the RE-induced changes in mTOR pathway signaling, muscle protein synthesis, inflammatory capacity, strength recovery, and power recovery. Although RE increased mTOR pathway signaling and inflammatory capacity after exercise and reduced maximal strength and explosive power the day after exercise, we observed no effects of alcohol (1.09 g ethanol∙kg-1 lean body mass, designed …
Date: August 2018
Creator: Levitt, Danielle E.
System: The UNT Digital Library
The Nature of the Impact of a Reading Tutoring Program on Participating Students in the Classroom: A Qualitative Study (open access)

The Nature of the Impact of a Reading Tutoring Program on Participating Students in the Classroom: A Qualitative Study

The purpose of this qualitative multi-case study was to explore the nature of the impact that a tutoring program, which featured preservice teachers as tutors, had on participating fifth grade at-risk students’ literacy behaviors in the classroom.The researcher served in the role of passive participant observer during the scheduled language arts period three days per week in the participating students’ classroom for a period of twenty-three weeks. Field notes were made in the classroom and coded, and audio tapes were recorded and transcribed of the tutoring sessions. Formal and informal interviews with the teacher, tutors, and participating students were conducted, transcribed, and coded. Lesson plans and reflections developed and written by the tutors were gathered and coded. Observations indicated that there were four types of reading required on a daily basis in the classroom. Assigned readings made by the teacher included narrative and expository texts. Pleasure readings were materials chosen by the students, but at certain times were teacher initiated and at other times, student initiated. The four types of reading found in the classroom were mirrored by the tutoring sessions. Students observed in the classroom could be divided into two types and four categories. Those with positive attitudes were …
Date: August 2000
Creator: Arrowood, Dana R.
System: The UNT Digital Library

Selected Songs for Chamber Winds and Soprano: Rediscovering a Forgotten Repertoire of John Philip Sousa

Access: Use of this item is restricted to the UNT Community
For over one hundred years, the music-going public has reflected on the life and influence of America's “March King,” John Philip Sousa. His popularity as a bandleader was unprecedented, and his reputation as an entertainer captivated the imagination and intrigue of a nation. Sousa's fame was attained through the high standards showcased by his unparalleled concert organization, the Sousa Band. He is interminably linked to the march, and for his seventy-seven years he proved to be its prolific and outspoken champion. Sousa's songs, however, were among his favorite works, and their presence on concert programs reinforced a variety of programming that was the hallmark of his success. The Sousa Band served as a cultural and musical ambassador, and annual transcontinental tours brought music to people where they lived. Sousa's songs were highly anticipated concert features, and were presented by soprano soloists known as the “Ladies in White.” A chamber winds instrumentation, rather than employment of the full-forces of the Sousa Band, allowed for an appropriate musical balance between instruments and voice. The “Forgotten Songs of John Philip Sousa Project” involved the research, editing, and performance of songs housed in the Sousa Archives for Band Research at the University of Illinois. …
Date: December 2001
Creator: Hemberger, Glen J.
System: The UNT Digital Library
Social emanations: Toward a sociology of human olfaction. (open access)

Social emanations: Toward a sociology of human olfaction.

Within the discipline of sociology human olfaction is rich with social significance yet remains a poorly charted frontier. Therefore, the following discourse is aimed toward the development of a foundation for the sociological study of olfaction. It is formed by the dual goals of unearthing the social history of olfaction and of providing a viable sociological account of the manner in which smells affect human ontology. From these goals arise the following research questions: (1) Have the meaning and social relevance of odors and the olfactory sensorium changed throughout different periods of history?; (2) How have those in the lineage of eminent sociological thinkers addressed the phenomenon of human olfaction during these periods?; and (3) What is the process by which aromatic stimuli are transformed from simple chemical compounds, drifting in the atmosphere, into sensations in a sensory field and then on to perceived objects, to subjects of judgment and interpretation, and finally to bases of knowledge which form and continually reform individuals in the world? The weaving of the sociohistorical tapestry of smell is undertaken to provide examples from thousands of years lived experiences as to the fluid and sociologically complex nature of individuals' olfactory senses. This historical information …
Date: December 2007
Creator: Harris, Regina Gray
System: The UNT Digital Library
A two-year college typology for the 21st century: Updating and utilizing the Katsinas-Lacey classification system. (open access)

A two-year college typology for the 21st century: Updating and utilizing the Katsinas-Lacey classification system.

This study had two primary purposes. The first goal was to bring the 1993/1996 Katsinas-Lacey two-year college classification system into the 21st century using data from the 2000 United States Census and the National Center for Education Statistics' Integrated Postsecondary Educational Data System (IPEDS) surveys for the 2000-2001 and 2001-2002 academic years. The second goal was to create a descriptive portrait of the universe of two-year, publicly controlled institutions that primarily offer the associate's degree mapped against the updated classification system and to describe and discern similarities and differences within this particular population by class and subclass in terms of multiple measurable characteristics for which IPEDS data were available. The study, based upon classification theory utilized in social science and management sciences - particularly the work of Bailey and McKelvey - assessed the efficacy of a number of other recent proposed community college classification systems, the original Katsinas-Lacey system and the revised version of Katsinas-Lacey created through the current research. It found both the original Katsinas-Lacey system and the revised version to meet the criteria for a well-made classification model. The study includes directories of all colleges and universities in the United States that offer the associate's degree with geographic, …
Date: May 2005
Creator: Hardy, David Earl
System: The UNT Digital Library
An Analysis of Administrative Competence Needs in Selected Texas Public School Districts (open access)

An Analysis of Administrative Competence Needs in Selected Texas Public School Districts

The problem of this study was to determine the perceived needs of selected Texas public school administrators in the areas of competence addressed in the PEEL (Performance Evaluation of the Educational Leader) definition of administrative competence. The conclusions included the following: 1. Between levels of administrative activity, differences were indicated in the high indexes of perceived need on the competency statements between the superintendency-level staff members (superintendent and his advisory staff who hold "line" positions) and the building-level administrators (elementary principals, junior high principals, and senior high principals). 2. Superintendency-level staff members tend to exhibit higher perceived needs on the competency statements relating to instruction and student-oriented responsibilities than do building-level administrators. 3. The size of a school district in which an administrator is employed, the number of years that an administrator has in educational administration, and the highest degree earned by an administrator cause no significant differences to appear in the manner in which an administrator assesses his perceived need on a particular competency statement.
Date: May 1979
Creator: Wood, James R.
System: The UNT Digital Library
Strategic Management and the Effectiveness of Selected Social Responsibility Programs in Selected Multinational Corporations -- Empirical and Case Approach, with Perceptions of Top Management (open access)

Strategic Management and the Effectiveness of Selected Social Responsibility Programs in Selected Multinational Corporations -- Empirical and Case Approach, with Perceptions of Top Management

The research examines perceptions of top management in U. S. Multinationals (MNCs) about strategic management processes involving social responsibility, particularly issues on plant and employee safety, education and human resources, and health delivery and services. Strategic management processes consider setting objectives, environmental analyses, and evaluation of social responsibility programs emphasizing planning activities. The study focuses on firms' decision making in planning and execution of social responsibility programs and their impact on foreign country environments as perceived by company executives, at corporate headquarters and regional/subsidiary offices.
Date: August 1983
Creator: Haydel, Belmont F. (Belmont Felician)
System: The UNT Digital Library
Creeks and Open Spaces: Ned Fritz's Environmental Crusades (open access)

Creeks and Open Spaces: Ned Fritz's Environmental Crusades

Edward C. Fritz was one of the most influential environmentalists in Texas history. Although he took a circuitous route to environmental activism, Fritz evolved into a powerful force fighting on behalf of Texan nature. Participating in substantial actions throughout the second half of the twentieth century, Fritz's contributions to environmental activism resulted in the successful preservation of thousands of acres and multiple wildlife species. Fritz parlayed his legal background into effective activism, beginning his career with a successful lobbying campaign for protection of Harris Hawks. He led the campaign to stop a decades old plan for canalization of the Trinity River. The creation of COST combined Fritz's environmental focus with the concerns of economic conservatives to prevent a billion dollar government funded project that would have significantly altered the river. Fritz then led a cadre who took over efforts to establish a preserve in the Big Thicket national forest. He oversaw the foundation of a protected area far larger than original expectations, capitalizing on the growing awareness of environmental issues in the 1970s. Fritz's interest in the Big Thicket led to a fight against the Forest Service's practice of clearcutting and its effect on Red Cockaded Woodpeckers. Through litigation and …
Date: May 2020
Creator: Ingram, Jared S.
System: The UNT Digital Library

Acute and Sublethal Impacts of Crude Oil Photo-Induced Toxicity in an Early Life Stage Marine Fish (Sciaenops ocellatus) and Invertebrate (Americamysis bahia)

We investigated the modifying effects of ultraviolet (UV) light and chemical dispersant (Corexit 9500A) on crude oil toxicity in juvenile mysids (≤ 24 h) (Americamysis bahia) and larval red drum (24-72 hpf) (Sciaenops ocellatus). These results demonstrate that crude oil toxicity significantly increases with co-exposure to environmentally relevant UV levels in both species, indicating photo-induced toxicity. This toxicity was further exacerbated by the application of chemical dispersants which increased the dissolution and concentration of oil-derived polycyclic aromatic hydrocarbons (PAHs) in test solutions. To better understand the mechanisms and initiating events of this observed photo-induced toxicity, the incidence of apoptotic cell death and global transcriptomic changes were assessed in larval red drum (24-72 hpf) following co-exposure to crude oil and UV. These results showed that co-exposure to UV and low concentrations of crude oil (<1 µg/L ∑PAH50) induced apoptotic cell death in skin and eye tissue and altered transcriptomic pathways related to visual processing and dermatological disease. To link these cellular and molecular impacts of photo-induced toxicity to apical endpoints of ecological performance, sublethal impacts to growth, metabolic rate, and visually mediated behaviors were explored in larval red drum at 2 developmental stages. These results suggested that earlier life stages may …
Date: December 2023
Creator: Leads, Rachel Renee
System: The UNT Digital Library
A Competency-Based Program for Preparing the Future Elementary Teacher in Health (open access)

A Competency-Based Program for Preparing the Future Elementary Teacher in Health

The problem under consideration in this study is a description of teacher preparation for elementary school health instruction. The dissertation is organized into six chapters, which are as follows: Introduction, Review of Related Literature, Procedures for Collection and Treatment of Data, Input from Texas Teachers, Competency-Based Health Education, and Summary and Recommendations. The following recommendations are made: (1) the program should be implement into the undergraduate tacher preparation program; (2) revision should be made based upon data collected during implementation; (3) research to produce objective questions for pretesting and posttesting purposes in each of the competency areas would be beneficial; and, (4) the Dearborn College Health Knowledge Test should be administered to those students who complete the program, and a comparison of scores made.
Date: December 1974
Creator: Wilson, Betty Ann Gunstream
System: The UNT Digital Library