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The Shifting Borders of Egypt (open access)

The Shifting Borders of Egypt

The formation of state borders is often told through the history of war and diplomacy. What is neglected is the tale of how borders of seemingly peaceful and long-extant places were set. In drawing Egypt’s borders, nineteenth-century cartographers were drawing upon a well of knowledge that stretched back into antiquity. Relying on the works of Greco-Roman writers and the Bible itself, cartographers and explorers used the authority of these works to make sense of unfamiliar lands, regardless of any current circumstances. The border with Palestine was determined through the usage of the Old Testament, while classical scholars like Herodotus and Ptolemy set the southern border at the Cataracts. The ancient cartography of Rome was overlaid upon the Egypt of Muhammad Ali. Given the increasing importance Egypt had to the burgeoning British Empire of the nineteenth century, how did this mesh with the influences informing cartographical representations of Egypt? This study argues that the imagined spaces created by Western cartographers informed the trajectory of Britain’s eventual conquest of Egypt. While receding as geopolitical concerns took hold, the classical and biblical influences were nonetheless part of a larger trend of Orientalism that colored the way Westerners interacted with and treated the people …
Date: May 2015
Creator: Chavez, Miguel Angel
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Structure, Composition, and Regeneration of Cross Timbers Forest Fragments in Different Land Use Contexts (open access)

Structure, Composition, and Regeneration of Cross Timbers Forest Fragments in Different Land Use Contexts

Throughout its current range, the Cross Timbers forest ecosystem is vulnerable to land-use change. In this study, we examined the surrounding land use matrix on the vegetation structure, composition and regeneration of six Cross Timbers forest fragments in Denton County, Texas (north of the Dallas-Fort Worth metroplex). Two fragments adjacent to agricultural land, two to residential neighborhoods, and two formally protected forest sites were selected. In summer 2015, five 100 m2 plots were randomly established in each fragment at least 200 meters from the edge. In each plot, all live and dead trees ≥ 3 cm diameter were identified and their height and diameter at breast height (DBH at 1.3 m aboveground) measured. Evidence of dumping (presence of trash) was recorded as an index of human frequentation. Differences in vegetation structure among the forest fragments were found. Most notably, fragments adjacent to agriculture contained 25% to 50% fewer trees per hectare than all other sites (Kruskal-Wallis, p < 0.02), especially trees <10 cm DBH. However, residential fragments had fewer trees that were ≥15 cm DBH compared to the other fragments, indicating that these are the youngest of the forest patches surveyed. Trash was observed in 60% of plots surveyed at …
Date: May 2015
Creator: Dunn, Ingrid
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Airbourne WiFi Networks Through Directional Antenna: An Experimental Study (open access)

Airbourne WiFi Networks Through Directional Antenna: An Experimental Study

In situations where information infrastructure is destroyed or not available, on-demand information infrastructure is pivotal for the success of rescue missions. In this paper, a drone-carried on demand information infrastructure for long-distance WiFi transmission system is developed. It can be used in the areas including emergency response, public event, and battlefield. The WiFi network can be connected to the Internet to extend WiFi access to areas where WiFi and other Internet infrastructures are not available. In order to establish a local area network to propagate WIFI service, directional antennas and wireless routers are used to create it. Due to unstable working condition on the flying drones, a precise heading turning stage is designed to maintain the two directional antennas facing to each other. Even if external interferences change the heading of the drones, the stages will automatically rotate back to where it should be to offset the bias. Also, to maintain the same flying altitude, a ground controller is designed to measure the height of the drones so that the directional antennas can communicate to each other successfully. To verify the design of the whole system, quite a few field experiments were performed. Experiments results indicates the design is reliable, …
Date: May 2015
Creator: Gu, Yixin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Effects of a Psychosocial Environment on College Women’s Exercise Regulations and Social Physique Anxiety (open access)

The Effects of a Psychosocial Environment on College Women’s Exercise Regulations and Social Physique Anxiety

A positive psychosocial intervention comprised of high autonomy support, task-involvement, and caring was implemented in physical activity classes to examine its effects on college women’s basic psychological needs (i.e. autonomy, competence, relatedness), exercise regulations (i.e. external, introjected, identified, integrated, intrinsic) and social physique anxiety (SPA). We hypothesized that at the end of the semester, participants in the intervention group (N = 73) would report greater need satisfaction, more self-determined regulations and less SPA than participants in the non-intervention group (N = 60). At T1 and T2, both the intervention and non-intervention participants reported “agreeing” with experiencing an autonomy supportive, task-involving, and caring environment. Furthermore, both groups at T1 and T2 reported moderate SPA. No significant group differences were found at T1. At T2, significant group differences were observed in the intervention and non-intervention groups’ report of external regulation and intrinsic regulation. The results suggests that group exercise instructors are capable of creating a positive psychosocial environment to enhance students’ intrinsic motivation.
Date: May 2015
Creator: Alvarez, Ana
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Adult Attachment, Acculturation, and Help-seeking Attitudes of Latino College Students (open access)

Adult Attachment, Acculturation, and Help-seeking Attitudes of Latino College Students

Based on theoretical reasoning and empirical evidence, the present study examined the unique and shared effects of attachment anxiety, attachment avoidance, and acculturation on attitudes toward seeking professional help among Latino college students. The research participants included 149 bilingual Latino college students from a large, public southwestern university. Results of a multiple regression analysis indicated that attachment avoidance was positively associated with both the recognition of need for psychological help and stigma of seeking professional help. Acculturation to American society was found to be statistically insignificant in predicting help-seeking attitudes in this sample of the population. Findings from exploratory questions suggested that Latino individuals would most likely seek help from parents, close friends, and then professionals. This study suggested that Latino individuals with high attachment avoidance acknowledge the potential benefit of professional help-seeking but distrust the process of approaching others for help. Limitations, implications, and future research directions will be discussed.
Date: May 2015
Creator: Zamudio, Gabriel
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Student Teachers’ Changing Confidence in Teaching (open access)

Student Teachers’ Changing Confidence in Teaching

Research shows that student teachers find the mentor teacher and the student teaching experience itself the two most influential factors in their practicum experience. This study examined five student teachers and the two mentor teachers of each in elementary school settings within a metropolitan school district in North Texas. Lave and Wenger’s (1991, 2002) community of practice theory informed this study. Data sources included mentor teacher interviews, student teacher interviews, student teacher observations, student teacher/mentor teacher dialogue journals, and student teacher reflections. A collective case study approach was followed to gain a detailed understanding of the experiences of the five student teachers, looking specifically at their confidence in teaching and the factors associated with it. Findings indicated that the confidence in teaching of all five student teachers changed throughout their practicum experiences. Results suggested many factors influenced these changes. Student teachers shared that the student teaching experience, the grade level/subjects taught, their relationships with their students, and their relationships with their mentor teachers contributed to their confidence. The mentor teachers perceived that student teachers’ confidence could be influenced by consistency in classroom management and their interactions with their mentor teachers. Two areas of influence on student teacher confidence not uncovered …
Date: May 2015
Creator: Stearns, Catherine L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
An Evaluation of Reinforcement Effects of Preferred Items During Discrete-Trial Instruction (open access)

An Evaluation of Reinforcement Effects of Preferred Items During Discrete-Trial Instruction

This study compared the relative reinforcing efficacy of high-preferred and low-preferred stimuli, as determined by two types of preference assessments, on acquisition rates in three children diagnosed with an Autism Spectrum Disorder (ASD). The study also evaluated the indirect effects of preference on students’ stereotypy and problem behavior during instructional periods. Participants were presented with a task and provided high or low-preferred stimuli contingent upon correct responding. Results showed that acquisition occurred more rapidly in the highly preferred condition for some participants. Higher rates of problem behavior occurred in the low preferred condition for all participants. These results highlight the importance of utilizing preference assessment procedures to identify and deliver high-preferred items in skill acquisition procedures for individuals with ASD.
Date: May 2015
Creator: Rorer, Lynette
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Trajectory Analytics (open access)

Trajectory Analytics

The numerous surveillance videos recorded by a single stationary wide-angle-view camera persuade the use of a moving point as the representation of each small-size object in wide video scene. The sequence of the positions of each moving point can be used to generate a trajectory containing both spatial and temporal information of object's movement. In this study, we investigate how the relationship between two trajectories can be used to recognize multi-agent interactions. For this purpose, we present a simple set of qualitative atomic disjoint trajectory-segment relations which can be utilized to represent the relationships between two trajectories. Given a pair of adjacent concurrent trajectories, we segment the trajectory pair to get the ordered sequence of related trajectory-segments. Each pair of corresponding trajectory-segments then is assigned a token associated with the trajectory-segment relation, which leads to the generation of a string called a pairwise trajectory-segment relationship sequence. From a group of pairwise trajectory-segment relationship sequences, we utilize an unsupervised learning algorithm, particularly the k-medians clustering, to detect interesting patterns that can be used to classify lower-level multi-agent activities. We evaluate the effectiveness of the proposed approach by comparing the activity classes predicted by our method to the actual classes from the …
Date: May 2015
Creator: Santiteerakul, Wasana
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Application of the Correlation Consistent Composite Approach to Biological Systems and Noncovalent Interactions (open access)

Application of the Correlation Consistent Composite Approach to Biological Systems and Noncovalent Interactions

Advances in computing capabilities have facilitated the application of quantum mechanical methods to increasingly larger and more complex chemical systems, including weakly interacting and biologically relevant species. One such ab initio-based composite methodology, the correlation consistent composite approach (ccCA), has been shown to be reliable for the prediction of enthalpies of formation and reaction energies of main group species in the gas phase to within 1 kcal mol-1, on average, of well-established experiment, without dependence on experimental parameterization or empirical corrections. In this collection of work, ccCA has been utilized to determine the proton affinities of deoxyribonucleosides within an ONIOM framework (ONIOM-ccCA) and to predict accurate enthalpies of formation for organophosphorus compounds. Despite the complexity of these systems, ccCA is shown to result in enthalpies of formation to within ~2 kcal mol-1 of experiment and predict reliable reaction energies for systems with little to no experimental data. New applications for the ccCA method have also been introduced, expanding the utility of ccCA to solvated systems and complexes with significant noncovalent interactions. By incorporating the SMD solvation model into the ccCA formulation, the Solv-ccCA method is able to predict the pKa values of nitrogen systems to within 0.7 pKa unit (less …
Date: May 2015
Creator: Riojas, Amanda G.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Atomistic Simulations of Deformation Mechanisms in Ultra-Light Weight Mg-Li Alloys (open access)

Atomistic Simulations of Deformation Mechanisms in Ultra-Light Weight Mg-Li Alloys

Mg alloys have spurred a renewed academic and industrial interest because of their ultra-light-weight and high specific strength properties. Hexagonal close packed Mg has low deformability and a high plastic anisotropy between basal and non-basal slip systems at room temperature. Alloying with Li and other elements is believed to counter this deficiency by activating non-basal slip by reducing their nucleation stress. In this work I study how Li addition affects deformation mechanisms in Mg using atomistic simulations. In the first part, I create a reliable and transferable concentration dependent embedded atom method (CD-EAM) potential for my molecular dynamics study of deformation. This potential describes the Mg-Li phase diagram, which accurately describes the phase stability as a function of Li concentration and temperature. Also, it reproduces the heat of mixing, lattice parameters, and bulk moduli of the alloy as a function of Li concentration. Most importantly, our CD-EAM potential reproduces the variation of stacking fault energy for basal, prismatic, and pyramidal slip systems that influences the deformation mechanisms as a function of Li concentration. This success of CD-EAM Mg-Li potential in reproducing different properties, as compared to literature data, shows its reliability and transferability. Next, I use this newly created potential …
Date: May 2015
Creator: Karewar, Shivraj
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Palestinian Archipelago and the Construction of Palestinian Identity After Sixty-five Years of Diaspora: the Rebirth of the Nation (open access)

The Palestinian Archipelago and the Construction of Palestinian Identity After Sixty-five Years of Diaspora: the Rebirth of the Nation

This dissertation conceptualizes a Palestinian archipelago based on Mikhail Bakhtin’s theory of the chronotope, and uses the archipelago model to illustrate the situation and development of Palestinian consciousness in diaspora. To gain insight into the personal lives of Palestinians in diaspora, This project highlights several islands of Palestinian identities as represented in the novels: Dancing Arabs, A Compass for the Sunflower, and The Inheritance. The identities of the characters in these works are organized according to the archipelago model, which illustrates how the characters rediscover, repress, or change their identities in order to accommodate life in diaspora. Analysis reveals that a major goal of Palestinian existence in diaspora is the maintenance of an authentic Palestinian identity. Therefore, my description of the characters’ identities and locations in the archipelago model are informed by various scholars and theories of nationalism. Moreover, this dissertation illustrates how different Palestinian identities coalesce into a single national consciousness that has been created and sustained by a collective experience of suffering and thirst for sense of belonging and community among Palestinians. Foremost in the memories of all Palestinians is the memory of the land of Palestine and the dream of national restoration; these are the main uniting …
Date: May 2015
Creator: Shaheen, Basima
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Marvels of the Invisible (open access)

Marvels of the Invisible

This dissertation is comprised of a collection of poems preceded by a critical preface. The preface considers the consumed animal body as a metaphor in contemporary American poetry, specifically in the works of Galway Kinnell, Li Young Lee, and Brigit Pegeen Kelly. The consumption of the mute creature allows the poet to identify the human self in the animal other, and serves as a metaphor for our continuity with the natural world. I revise Owen Barfield’s notion of “original participation,” positing that through imaginative participation, the poet and the reader can identify the animal within the self, and thus approach a fuller understanding of both the self and the outside world. We identify the animal other within the human self, and in of this act of relating, we are able to temporarily transgress the boundaries of the individual self to create art that expresses continuity with the outside world. This argument brings about a discussion of text as an act of consumption, and the way and which this can symbolize the ways in which the self is altered through the act of reading. The book-length collection of poems, entitled Marvels of the Invisible, won Tupelo Press’s 2014 Berkshire prize for …
Date: May 2015
Creator: Molberg, Jenny, 1985-
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Burner Project: Privacy and Social Control in a Networked World (open access)

The Burner Project: Privacy and Social Control in a Networked World

As mobile phones become increasingly ubiquitous in today’s world, academic and public audiences alike are curious about the interaction between mobile technologies and social norms. To investigate this phenomenon, I examined how individuals use technology to actively manage their communication behaviors. Through a three-month research project on usage patterns of Burner, a mobile application, this thesis explores the relationships among technology, culture, and privacy. Burner is a service that equips individuals with the means to create, maintain, and/or dissolve social ties by providing temporary, disposable numbers to customers. The application offers a way to communicate without relying on a user’s personal phone number. In other words, Burner acts as a “privacy layer” for mobile phones. It also provides a valuable platform to examine how customers use the application as a strategy for communication management. This thesis represents a marriage of practice and theory: (1) As an applied enterprise, the project was constructed as a customer needs assessment intending to examine how the service was situated in the lives of its users. The findings have successfully been applied to my client’s company strategy and have led to a more informed customer approach. (2) As an academic endeavor, this research contributes to …
Date: May 2015
Creator: Shade, Molly
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Computational Studies of C–H/C–C Manipulation Utilizing Transition Metal Complexes (open access)

Computational Studies of C–H/C–C Manipulation Utilizing Transition Metal Complexes

Density Functional Theory (DFT) is an effective tool for studying diverse metal systems. Presented herein are studies of a variety of metal systems, which can be applied to accomplish transformations that are currently difficult/impossible to achieve. The specific topics studied utilizing DFT include: 1) C–H bond activation via an Earth-abundant transition metal complex, 2) C–H bond deprotonation via an alkali metal superbase, 3) and amination/aziridination reactions utilizing a CuI reagent. Using DFT, the transformation to methanol (CH3OH) from methane (CH4) was examined. The transition metal systems studied for this transformation included a model FeII complex. This first-row transition metal is an economical, Earth-abundant metal. The ligand set for this transformation includes a carbonyl ligand in one set of complexes as well as a phosphite ligand in another. The 3d Fe metal shows the ability to convert alkyls/aryls to their oxidized counterpart in an energetically favorable manner. Also, “superbasic” alkali metal amides were investigated to perform C—H bond cleavage. Toluene was the substrate of interest with Cs chosen to be the metal of interest because of the highly electropositive nature of this alkali metal. These highly electrophilic Cs metal systems allow for very favorable C—H bond scission with a toluene substrate. …
Date: May 2015
Creator: Pardue, Daniel B.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
GIS in AP Human Geography: a Means of Developing Students’ Spatial Thinking? (open access)

GIS in AP Human Geography: a Means of Developing Students’ Spatial Thinking?

Geography education is undergoing change in K-12 education due in part to the introduction of geospatial technologies, including geographic information systems (GIS). Although active engagement in GIS mapping would seem to enhance students’ spatial thinking, little is known about the mapping strategies that students employ or about changes in their geographic knowledge that would result. This study, set in a high school Advanced Placement human geography class, sought to contribute to these areas of inquiry. Participants performed a web-based GIS task focused on global population and migration. Attention in the study was on (a) the strategies students employed when investigating geographic phenomena using GIS, (b) changes in their cognitive maps, as assessed through sketch maps, resulting from the activity, (c) the relationship between GIS maps and sketch maps, and (d) the ways in which a subset of students serving as case studies explained the nature of their mapping. The study employed screen-captures, video-recordings, observations, pre- and post-study sketch maps, and interviews. Analyses of the GIS process revealed that, in creating their maps, the students used a number of strategies, which included searching, layering, removing layers of data, adjusting transparency, editing, and noting. Although searching and layering were employed by all …
Date: May 2015
Creator: Webster, Megan L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Automatic Language Identification for Metadata Records: Measuring the Effectiveness of Various Approaches (open access)

Automatic Language Identification for Metadata Records: Measuring the Effectiveness of Various Approaches

Automatic language identification has been applied to short texts such as queries in information retrieval, but it has not yet been applied to metadata records. Applying this technology to metadata records, particularly their title elements, would enable creators of metadata records to obtain a value for the language element, which is often left blank due to a lack of linguistic expertise. It would also enable the addition of the language value to existing metadata records that currently lack a language value. Titles lend themselves to the problem of language identification mainly due to their shortness, a factor which increases the difficulty of accurately identifying a language. This study implemented four proven approaches to language identification as well as one open-source approach on a collection of multilingual titles of books and movies. Of the five approaches considered, a reduced N-gram frequency profile and distance measure approach outperformed all others, accurately identifying over 83% of all titles in the collection. Future plans are to offer this technology to curators of digital collections for use.
Date: May 2015
Creator: Knudson, Ryan Charles
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Belief Transfers in Co-branding and Brand Extension and the Roles of Perceptual Fit (open access)

Belief Transfers in Co-branding and Brand Extension and the Roles of Perceptual Fit

Existing co-branding and brand extension research generally coalesces around two important constructs: perceptual fit and attitude toward the brand. Studies in co-branding and brand extension to date have generally emphasized the transference of affective elements of attitude from parent brand to the extension. Researchers and practitioners clearly need to learn more about the transfer of belief, the cognitive elements of attitude. Too little is currently known about whether and how beliefs are actually transferred in co-branding and brand extension applications, particularly in terms of perceptual fit. This dissertation investigates belief transfer and the effect of perceptual fit on belief transfer in co-branding and brand extension scenarios and develops answers to the following research questions: 1.Are different categories of beliefs transferable from parent brand to theextension? 2.How do various sub-dimensions of perceptual fit affect belief transfers fromparent brands to the extension? 3.How do different categories of beliefs affect consumers’ intentions to purchasethe extension products? Categorization Theory was used as the fundamental theory to build the hypotheses. This dissertation involved qualitative studies, belief scale development, and experimental design studies. The results revealed that aesthetic and functional beliefs are positively transferred from parent brand to the extension. The transfer of aesthetic beliefs is …
Date: May 2015
Creator: Roswinanto, Widyarso
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Restoration Techniques for Northern Bobwhites (open access)

Restoration Techniques for Northern Bobwhites

Isolated populations of northern bobwhites (Colinus virginianus) have declined causing many quail managers to attempt population restoration by releasing captive-reared bobwhites or translocating wild bobwhites. I evaluated three restoration techniques: (1) release of captive-reared bobwhites, (2) translocation of bobwhites from high densities to low densities, and (3) release of captive-reared and translocated bobwhites acclimated on site prior to release. These results show that captive-reared birds have reduced survival and fewer nesting attempts when compared to translocated birds and that acclimation time was not a factor. I hypothesized that high mortality rates were caused by captive-reared birds exhibiting different predator avoidance behavior than wild birds. Captive-reared and wild-trapped bobwhites were subjected to independent predator simulations and their responses were recorded on high definition video. Threat recognition time, reaction type, and reaction time was recorded for comparative analysis. Pen-reared birds recognized the simulated raptorial and terrestrial predator threats quicker than wild-trapped birds, but reaction times were not different among groups. However, the type of reaction was different among groups where pen-reared birds typically flushed immediately upon recognizing either simulated predator as compared to wild-trapped birds which typically ran or held when subjected to the raptorial threat and showed little to no observable …
Date: May 2015
Creator: Newman, William L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Combinatorial Assessment of the Influence of Composition and Exposure Time on the Oxidation Behavior and Concurrent Oxygen-induced Phase Transformations of Binary Ti-x Systems (open access)

Combinatorial Assessment of the Influence of Composition and Exposure Time on the Oxidation Behavior and Concurrent Oxygen-induced Phase Transformations of Binary Ti-x Systems

The relatively low oxidation resistance and subsequent surface embrittlement have often limited the use of titanium alloys in elevated temperature structural applications. Although extensive effort is spent to investigate the high temperature oxidation performance of titanium alloys, the studies are often constrained to complex technical titanium alloys and neither the mechanisms associated with evolution of the oxide scale nor the effect of oxygen ingress on the microstructure of the base metal are well-understood. In addition lack of systematic oxidation studies across a wider domain of the alloy composition has complicated the determination of composition-mechanism-property relationships. Clearly, it would be ideal to assess the influence of composition and exposure time on the oxidation resistance, independent of experimental variabilities regarding time, temperature and atmosphere as the potential source of error. Such studies might also provide a series of metrics (e.g., hardness, scale, etc) that could be interpreted together and related to the alloy composition. In this thesis a novel combinatorial approach was adopted whereby a series of compositionally graded specimens, (Ti-xMo, Ti-xCr, Ti-xAl and Ti-xW) were prepared using Laser Engineered Net Shaping (LENS™) technology and exposed to still-air at 650 °C. A suite of the state-of-the-art characterization techniques were employed to assess …
Date: May 2015
Creator: Samimi, Peyman
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Plasma Interactions on Organosilicate Glass Dielectric Films and Emerging Amorphous Materials- Approach to Pore Sealing and Chemical Modifications (open access)

Plasma Interactions on Organosilicate Glass Dielectric Films and Emerging Amorphous Materials- Approach to Pore Sealing and Chemical Modifications

In-situ x-ray photoemission (XPS) and ex-situ FTIR studies of nanoporous organosilicate glass (OSG) films point to the separate roles of radicals vs. VUV photons in the carbon abstraction. The studies indicate that reaction with O2 in presence of VUV photons (~123 nm) result in significant carbon abstraction within the bulk and that the kinetics of this process is diffusion-limited. In contrast, OSG exposed to atomic O (no VUV) results in Si-C bond scission and Si-O bond formation, but this process is self-limiting after formation of ~1 nm thick SiO2 surface layer that inhibits further diffusion. Therefore, the diffusion-dominated kinetics of carbon abstraction observed for OSG exposed to O2 plasma is definitively attributed to the diffusion of O2 down OSG nanopores, reacting at photo-activated sites, rather than to the diffusion of atomic O. Pretreatment of OSG by 900 eV Ar+ ion bombardment also results in formation of 1 nm thick SiO2-like surface overlayer that inhibits O2 diffusion, inhibiting VUV+O2 and O2 plasma-induced reactions, and that the effectiveness of this treatment increases with ion kinetic energy. On the contrary, organosilicate glass (OSG) films with backbone carbon (-Si-R-Si-) exhibit significantly enhanced resistance to carbon loss upon exposure to O2 plasma, radicals and VUV+O2 …
Date: May 2015
Creator: Kazi, Haseeb
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Forward Genetic Characterization of Medicago truncatula Tnt1 Insertion Mutants Defective in Nodule Development and Symbiotic Nitrogen Fixation (open access)

Forward Genetic Characterization of Medicago truncatula Tnt1 Insertion Mutants Defective in Nodule Development and Symbiotic Nitrogen Fixation

Legumes are unique plants because they form special structures “nodules”, via symbiotic relationships with rhizobial bacteria present in the soil. Once rhizobia mature inside nodules, they fix atmospheric nitrogen providing a source of bioavailable nitrogen to the plant. To discover novel genetic components involved in the legume-rhizobia symbiosis by using forward genetic screening, we have isolated Medicago truncatula Tnt1 insertion mutants in the R108 ecotype, which are defective in nodule development and symbiotic nitrogen fixation in response to Sinorhizobium meliloti. Out of three mutants NF11044, NF11217 and NF8324, one of the mutants showed brown nodules and Fix- phenotype that is defective in symbiotic nitrogen fixation. The other two mutants showed white nodules and Fix- phenotype, also indicator of defects in symbiotic nitrogen fixation. To identify the underlying mutation causing the phenotype, we have developed molecular genetic markers by obtaining genomic sequences flanking the Tnt1 insertions by TAIL-PCR and Illumina sequencing. To carry out co-segregation analysis, back-crossed BC1F2 segregating populations were obtained. These are being phenotyped, genotyped and analyzed for co-segregation of the phenotype with the Tnt1 genetic markers. Back-crossing also has the effect of reducing the Tnt1 insertions, which are not linked to the nodulation defective phenotypes. Out of the …
Date: May 2015
Creator: Kadel, Khem L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Case Study of an Urban Charter School’s Journey of School Improvement: Organizational Theory, Institutional Learning and School Reform (open access)

A Case Study of an Urban Charter School’s Journey of School Improvement: Organizational Theory, Institutional Learning and School Reform

The problem for this study was the need to increase and maintain in student achievement in charter schools. The purpose of this single-case study was to discover how an inner city charter school with a high percentage of at-risk students increased overall student achievement and attained acceptable performance status when faced simultaneously with administrative challenges and increases in state and federal standards. The participants for the single-case study included the school district’s superintendent, the high school principal, the dean of students, four faculty of the district, and one outside consultant appointed to work with the district by the state of Texas. The sampling for this study allowed for the opportunity to study in greater depth the choice of reform strategies and organizational structure designed to result in increased student achievement and student success over the course of two years. Since this was a single-case study of one charter school district, participants were referenced by the role in which they served. All district, campus, and participant names remained anonymous. The results showed the increased student achievement was made possible by several reform strategies and best practices. The primary reform strategies and best practices that had the greatest impact were consistent campus …
Date: May 2015
Creator: Subjinski, Amanda
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Manipulations of Sucrose/Proton Symporters and Proton-pumping Pyrophosphatase Lead to Enhanced Phloem Transport But Have Contrasting Effects on Plant Biomass (open access)

Manipulations of Sucrose/Proton Symporters and Proton-pumping Pyrophosphatase Lead to Enhanced Phloem Transport But Have Contrasting Effects on Plant Biomass

Delivery of photoassimilate, mainly sucrose (Suc) from photoautotrophic source leaves provides the substrate for the growth and maintenance of sink tissues such as roots, storage tissues, flowers and fruits, juvenile organs, and seeds. Phloem loading is the energized process of accumulating solute in the sieve element/companion cell complex of source leaf phloem to generate the hydrostatic pressure that drives long-distance transport. In many plants this is catalyzed by Suc/Proton (H+) symporters (SUTs) which are energized by the proton motive force (PMF). Overexpression of SUTs was tested as means to enhance phloem transport and plant productivity. Phloem specific overexpression of AtSUC2 in wild type (WT) tobacco resulted in enhanced Suc loading and transport, but against the hypothesis, plants were stunted and accumulated carbohydrates in the leaves, possibly due to lack of sufficient energy to support enhanced phloem transport. The energy for SUT mediated phloem loading is provided from the PMF, which is ultimately supplied by the oxidation of a small proportion of the loaded photoassimilates. It was previously shown that inorganic pyrophosphate (PPi) is necessary for this oxidation and overexpressing a proton-pumping pyrophosphatase (AVP1) enhanced both shoot and root growth, and augmented several energized processes like nutrient acquisition and stress responses. …
Date: May 2015
Creator: Khadilkar, Aswad S
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Training Package for Parents and their Toddlers with Autism: Observed Changes in Parent Teaching Episodes, Child Turn Taking and Social Attending, and Parent-Child Engagement (open access)

A Training Package for Parents and their Toddlers with Autism: Observed Changes in Parent Teaching Episodes, Child Turn Taking and Social Attending, and Parent-Child Engagement

Research has shown that parents of children with autism report higher stress than parents of children with other developmental disabilities. It has been suggested that parent training programs, specifically naturalistic social-communication training, can reduce parental stress and enhance the quality of the parent-child relationship. Although the development of a multilevel assessment has been suggested, much of the research in this area has relied on measures of parent implementation fidelity and specific child target skills such as vocal communication, eye contact, and joint attention. Few have directly measured the parent-child interaction. The purpose of the current study is to examine the effects of an in-home parent training package for toddlers with autism on parent-child social interactions. Within this package, parents are taught to attend to contextual variables, to arrange the environment to set the occasion for child responding, to respond immediately to targeted child approximations, and to respond in ways that are mutually reinforcing, social, and fun. Data were collected during 5-min video-taped assessments, on the number of parent teaching episodes, child target skills (turn taking and social attending), engagement, and synchronous engagement. Results were evaluated in a multiple baseline design across two parent-child dyads and indicated increases in all measures. …
Date: May 2015
Creator: Hunt, Nina Marie
Object Type: Thesis or Dissertation
System: The UNT Digital Library