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Discriminative Control of Behavioral Variability in Video Game Play (open access)

Discriminative Control of Behavioral Variability in Video Game Play

Creativity can be a useful skill in today's classrooms and workplaces. When individuals talk about creativity, it's unclear what the controlling variables are when we tact behavior as "creative." Research in understanding the processes behind behaviors that are considered "creative" would assist in identifying functional relations and provide insight on how to teach creativity. Since creativity is often described as doing something different from the norm, behavioral variability may be a potential aspect of creativity. This study aimed to replicate previous findings by investigating the effects of discrimination training in a multiple schedule of varied and repetitive responding in the context of a video game. Participants played through a 2D online video game made in Bloxels. Different alternating-colored platforms served as the discriminative stimuli for the vary and repeat components. Three parameters of variability were measured (e.g., left jumps, right jumps, and double jumps). The results of the study indicate that participants were able to learn the discrimination of when to repeat and vary their responses depending on which colored platform they encountered.
Date: May 2023
Creator: Arias, Gabriela Isabel
System: The UNT Digital Library
Analysis of "The Seven Songs" From The Pilgrim's Progress By Ralph Vaughan Williams (open access)

Analysis of "The Seven Songs" From The Pilgrim's Progress By Ralph Vaughan Williams

The opera, The Pilgrim's Progress, was written by Ralph Vaughan Williams in 1949. "The Seven Songs" are analyzed for performance, examining the elements of music and text of the songs, including melody, harmony, form, vocal line and accompaniment, with the intent of forming conclusions in regard to their usefulness as singular selections, or as a group, for performance.
Date: May 1968
Creator: Hindman, Jannette
System: The UNT Digital Library

Additive Friction Stir Deposition of Al-Ce Alloys for Improved Strength and Ductility

Additive friction stir deposition (AFSD) is a solid-state additive manufacturing (AM) technique that breaks down large constituent particles into more refined and uniformly disturbed microstructure. AFSD was used to print Al-Ce alloys. Current commercial Al-alloys upon elevated temperatures go through dissolution and coarsening of strengthening precipitates causing mechanical degradation of these alloys. Al-Ce alloys do not have this issue as cerium's low solubility restricts dissolution into the aluminum matrix at elevated temperatures, thus giving great thermal stability to the microstructure. Al-Ce alloys lack solid solubility that affects the solid solution strengthening and precipitation strengthening. Al-Ce alloys have limitation at room temperature as they can only reach a maximum of ~65 MPa yield strength. Elements like magnesium have been added to alloy to enable solid solution strengthening, and scandium to enable precipitation strengthening to improve strength before going through the AFSD process. By adding new elements to the Al-Ce alloys, an increase in the yield strength from ~60 MPa to ~200 MPa was achieved before AFSD. The casted alloys form coarse particles that reach 300 µm in size; resulting in stress concentration that causes material fracture before necking, giving >10% ductility. AFSD breaks down these coarse particles to increase strength and …
Date: December 2023
Creator: Davis, Devin Fredric
System: The UNT Digital Library
Utility Trombone Playing: A Practical Method for Students to Achieve Mastery of Alto, Tenor and Bass Trombone (open access)

Utility Trombone Playing: A Practical Method for Students to Achieve Mastery of Alto, Tenor and Bass Trombone

With the importance of versatility in freelance work in the world of trombone performance, along with increased competition for that work, the need for players to play alto, tenor, and bass trombones to a high level of proficiency has become more and more crucial. This, coupled with the growing number of orchestras looking to hire musicians who are highly competent on all three instruments means that university professors need to be able to teach all three instruments. This evolution of the job market is driving a need for pedagogical material that is specifically designed to address the unique challenges of practicing and performing at a professional level on the main three instruments in the trombone family. As of the time of writing, this material simply does not exist. This project aims to fill that instructional gap. It gives students and teachers a resource that outlines an approach for a four-year undergraduate course of study that allows for the development of the playing of each of the trombones individually and collectively, utilizing the strengths of one instrument to develop the other two. It will also allow for the exploration of the technical challenges that arise when playing and changing between instruments. …
Date: December 2023
Creator: Owner, Timothy Michael
System: The UNT Digital Library
Experimental and Numerical Investigation of a Novel Cold-Formed Steel Long Span Truss (open access)

Experimental and Numerical Investigation of a Novel Cold-Formed Steel Long Span Truss

This thesis describes the experimental and numerical investigation of a novel cold-formed steel 48ft and 54ft long span truss. The truss we designed was to be used as the roofs of large buildings, such as warehouses, hangars, sports arenas. The investigation includes both experimental and numerical testing, the experimental testing of the truss under uniform loads (increasing loads) to determine its deflection and load carrying capacity. The numerical test included developing a finite element model of the truss in SolidWorks and using a finite element model of the truss in ABAQUS to simulate the experimental tests. The findings of this study can be used to improve the design of cold-formed steel long span trusses. The study also provides valuable information for future studies on the modeling of trusses with different cold-formed steel members and the behavior of trusses under load.
Date: December 2023
Creator: Nalla, Sai Kumar
System: The UNT Digital Library
Exploring the ROI of 1:1 Computing Programs at the High School Level (open access)

Exploring the ROI of 1:1 Computing Programs at the High School Level

This dissertation explored the cost and value of 1:1 computing programs in high schools in Texas. The study examines whether the total cost of ownership of these programs can be justified by the student testing gains and graduation rates. It investigates whether student learning outcomes show a definable correlation between positive gains and the implementation of 1:1 computing programs. The study also explores whether there is a measurable return on investment of 1:1 programs based on testing gains and graduation rates. The research used the State of Texas Assessment of Academic Readiness exam scores to validate assumptions and test the hypothesis. The study found no clear link between the addition of 1:1 computing programs and the realms of student success. While there is marginal improvement in student outcomes, there is only circumstantial evidence that laptops and devices are the catalysts for the change. The dissertation also found that the total cost of ownership (TCO) is a significant portion of the district's spending, costing millions of dollars, and that the financial disclosure and budget information data was either missing, incomplete, or over-generalized, causing an issue for assessing program effectiveness or ROI. Despite this lack of transparency, there is a slight positive …
Date: December 2023
Creator: Kissel, Tara Michelle
System: The UNT Digital Library

Magnetoresponsive Layer-by-Layer (LBL) Polyelectrolyte Microcapsules Exposed to Low Frequency Alternating Magnetic Field for Drug Delivery to Breast Cancer Cells

Layer-by-layer (LBL) polyelectrolyte capsules can be modified to incorporate stimuli such as superparamagnetic nanoparticles which respond to a magnetic field only when it is turned on. Thus, they can act as a switch to load or unload their drug cargo on demand. Specifically, magnetite is incorporated into bilayer capsules made of alternating poly(allylamine hydrochloride) (PAH) and poly(sodium-p-styrenesulfonate) (PSS) which surrounds calcium carbonate core. The core is then dissolved using ethylenediaminetetraacetic acid (EDTA). These capsules are loaded with at FITC-BSA conjugate and examined with fluorescence to show the unloading of the FITC-BSA from capsules as it brightens the entire field of view of the microscope. The results suggest that we can next load and unload an anticancer drug such as doxorubicin using the combination of microcapsule and alternating magnetic field (AMF) to treat the cancer cells. Preliminary data interprets that the low frequency AMF we use has little to no adverse effect cells viability. This coincides with the general thought that low frequency AMF signals are not harmful to humans. Therefore, as an alternative to hyperthermia methods which use heat, it may be possible to deliver the anticancer drugs specifically to the cells when and where it is needed.
Date: December 2023
Creator: Powell, Robert Darrel
System: The UNT Digital Library

The Idiomatic Techniques and Procedures of Composer Kevin Walczyk (b. 1964) that Define a Unique Musical Language

Award winning composer Kevin Walczyk's describes himself as a "musical storyteller," using all musical elements of structure, melody, harmony, and counterpoint to convey programmatic content. A variety of subjects are conveyed that include historical events, people, physical objects or locations, and literary texts. Deeper matters, such as spiritual themes, are also often incorporated in his music that enhance the musical program. The technical procedures employed—pertaining particularly to the expression of programmatic content—has produced a unique musical language that stands out in the modern compositional landscape. What are these inherent idiomatic features, and how are they exhibited? The purpose of this dissertation is to provide a detailed examination of Walczyk's distinct musical language. A critical analysis of the technical procedures used to convey his programmatic content, as well as insights into his influences and writing process, illuminate the attributes of this a posteriori musical language. The two works selected for this study to demonstrate this are Symphony No. 2: Epitaphs Unwritten and Talking Winds, both written for wind band.
Date: December 2023
Creator: Wollam, Seth Frederick
System: The UNT Digital Library
"To Swim In Air Forever Tooloud Laughcrying" (open access)

"To Swim In Air Forever Tooloud Laughcrying"

This thesis' focal presentable object – to swim in air – is a mythosystem comprising six iteratively malleable experiential systems of intermedial musical and visual performance works composed by myself between the years 2018 and 2023. Conceived through the lens of Jennifer Walshe's New Discipline, created within my practice cycle's nodal context, and connected by a sub/conscious structure of perceptual timbre, the mythosystem and its parts form the centerpiece of this discussion of context, process, and method. As described in this document, the creative practice of nodal context and the adaptive intermedial methods used in the conceptualization and composition of to swim in air were developed through a personal and pragmatic application of feminist writer and independent scholar Sarah Ahmed's Queer Phenomenology: Orientations, Objects, Others, and composer, musicologist and trombonist George Lewis' curatorial decolonization guidelines as outlined in his "8 Difficult Steps to Decolonizing Music" towards the creation of presentable cultural objects which invite variable and continuous interaction from their participants through the exploration of the reciprocity of community, multi-practice creative strategy and malleable forms. Throughout this document I discuss how through the exploration of the reciprocity of community, multi-practice creative strategy and malleable forms I have addressed concerns of …
Date: December 2023
Creator: Fristensky, Louise Anne
System: The UNT Digital Library

Thermodynamics, Kinetics and Mechanical Behavior of Model Metallic Glasses

The thermophysical properties and deformation behavior of a systematic series of model metallic glasses was investigated. For Zr-based metallic glasses with all metallic constituents, the activation energy of glass transition was determined to be in the range of 74-173 kJ/mol while the activation energy of crystallization was in the range of 155-170 kJ/mol. The reduced glass transition temperature was roughly the same for all the alloys (~ 0.6) while the supercooled liquid region was in the range of 100-150 K, indicating varying degree of thermal stability. In contrast, the metal-metalloid systems (such as Ni-Pd-P-B) showed relatively higher activation energy of crystallization from short range ordering in the form of triagonal prism clusters with strongly bonded metal-metalloid atomic pairs. Deformation mechanisms of all the alloys were investigated by uniaxial compression tests, strain rate sensitivity (SRS) measurements, and detailed characterization of the fracture surface morphology. For the metal-metal systems, plasticity was found to be directly correlated with shear transformation zone (STZ) size, with systems of larger STZ size showing better plasticity. In metal-metalloid amorphous alloys, plasticity was limited by the distribution of STZ units, with lower activation energy leading to more STZ units and better plasticity. The alloys with relatively higher plasticity …
Date: December 2023
Creator: Akhtar, Mst Alpona
System: The UNT Digital Library

Building a Digital Twin of the University of North Texas Using LiDAR and GIS Data

Digital twins are virtual renditions of the actual world that include real-world assets, connections, activities, and processes. Recent developments in technologies play a key role in advancing the digital twin concept in urban planning, designing, and monitoring. Moreover, the latest developments in remote sensing technology have resulted in accurate city-scale light detection and ranging (LiDAR) data, which can be used to represent urban objects (buildings, vegetation, roads, and utilities), enabling the creation of digital twin of urban landscapes. This study aims to build a digital twin of the University of North Texas (UNT) using LiDAR and GIS data. In this research, LiDAR point clouds are used to create 3D building and vegetation modeling along with other GIS data (bicycle racks and parking areas) in creating a digital twin model. 3D Basemap solutions of ArcGIS Pro and ArcGIS Online Scene Viewer, respectively, are used to create an initial 3D urban model and build the ultimate digital twin of UNT. The emergency management floorplans of UNT buildings are incorporated into the digital twin to increase emergency management efficiency. Moreover, solar power potential for individual buildings at UNT has been estimated using the Digital Surface Model (DSM) and integrated into the digital twin …
Date: December 2023
Creator: Bhattacharjee, Shwarnali
System: The UNT Digital Library
"The Gordita's Guide to Body Positivity" (open access)

"The Gordita's Guide to Body Positivity"

"The Gordita's Guide to Body Positivity" is an autobiographical documentary reflecting on society's expectations of the female body image and how it affects Latinx women. Through personal recollections, media content, and archival material, the film explores beauty expectations, body discrimination, and body positivity. The document analyzes the documentary styles such as autoethnography and narration incorporated into the film and provides historical and theoretical context to body image in the Latinx culture and how the media has affected body image, beauty ideals, and eating disorders. In addition, the pre-production, production, and post-production process is detailed.
Date: December 2023
Creator: Calderon, Jessica Andrea
System: The UNT Digital Library

Option Pricing Under New Classes of Jump-Diffusion Processes

In this dissertation, we introduce novel exponential jump-diffusion models for pricing options. Firstly, the normal convolution gamma mixture jump-diffusion model is presented. This model generalizes Merton's jump-diffusion and Kou's double exponential jump-diffusion. We show that the normal convolution gamma mixture jump-diffusion model captures some economically important features of the asset price, and that it exhibits heavier tails than both Merton jump-diffusion and double exponential jump-diffusion models. Secondly, the normal convolution double gamma jump-diffusion model for pricing options is presented. We show that under certain configurations of both the normal convolution gamma mixture and the normal convolution double gamma jump-diffusion models, the latter exhibits a heavier left or right tail than the former. For both models, the maximum likelihood procedure for estimating the model parameters under the physical measure is fairly straightforward; moreover, the likelihood function is given in closed form thereby eliminating the need to embed a probability density function recovery procedure such as the fast Fourier transform or the Fourier-cosine expansion methods in the parameter estimation procedure. In addition, both models can reproduce the implied volatility surface observed in the options data and provide a good fit to the market-quoted European option prices.
Date: December 2023
Creator: Adiele, Ugochukwu Oliver
System: The UNT Digital Library
Exploring the Association of Language Brokering and Parent-Child Relationship in Korean Immigrant Families (open access)

Exploring the Association of Language Brokering and Parent-Child Relationship in Korean Immigrant Families

This study focuses on investigating the dynamics of language brokering as Korean immigrant families experience environmental challenges associated with immigration. This study was conducted with qualitative research design with purposive sampling of Korean immigrant families. Six parent-child dyads were recruited and participating children were between 12 to 16 years old. Semi-structured interviews were conducted separately with parents and children in either English or Korean. Thematic analysis was employed for analyzing the transcribed interviews. The Dedoose software program was applied to assist the coding process. 12 subthemes were revealed under four main themes, which were aligned to the study's research questions. The twelve subthemes included parents' dependence on children, vulnerability and resilience of Korean immigrant families, children's socioemotional development through language brokering, and the role of first-born daughter in the family. Parent and child responses indicated how language brokering affects can be a risk in relation to children's development (i.e., with responsibility of language brokering leading the child to experience stress or experience the responsibility of translation as a burden. Positively, respondents indicated that the parent and child experienced a greater sense of empathy for each other's roles. The results derived from this study were aligned with the results of previous …
Date: December 2023
Creator: Lee, Eunkyung
System: The UNT Digital Library
Rethinking the Study of Conflict and Peace: Making Causal Inferences in Quantitative Conflict and Peace Research (open access)

Rethinking the Study of Conflict and Peace: Making Causal Inferences in Quantitative Conflict and Peace Research

Most research questions and theory in quantitative peace and conflict research are fundamentally causal. However, a large gap exists in the extant literature between research question and research methodology. Not only does most existing methodology fail to achieve what most quantitative peace scholars attempt, but many researchers do not appear to be aware of these limitations. In this dissertation, I outline five key shortcomings within this literature that, left unaddressed, create results that are not informative of the questions quantitative peace researchers are interested in. This dissertation demonstrates solutions addressing these shortcomings with two applied chapters, conducting causal research designs on a study examining the economic impact of United Nations peacekeeping operations and the effect of human rights treaties on repression, respectively. I find that conventionally-established results in the literature change dramatically when exposed to methodological changes informed by the causal inference literature.
Date: December 2023
Creator: Lookabaugh Jr., Brian Scott
System: The UNT Digital Library
Investigating Novel Streptomyces Bacteriophage Endolysins as Potential Antimicrobial Agents (open access)

Investigating Novel Streptomyces Bacteriophage Endolysins as Potential Antimicrobial Agents

As antibiotic resistance has become a major global threat, the World Health Organization has urgently called scientists for alternative strategies for control of bacterial infections. Endolysin, a protein encoded by a phage gene, can degrade bacterial peptidoglycan (PG). Currently, there are three endolysin products in the clinical phase. We, thus, are interested in exploring novel endolysins from Streptomyces phages as only a few of them have been experimentally characterized. Using bioinformatics tools, we identified nine functional domain groups from 250 Streptomyces phages putative endolysins. NootNoot gp34 (transglycosylase; Nt34lys), Nabi gp26 (amidase; Nb26lys), Tribute gp42 (PGRP; Tb42lys), and LazerLemon gp35 (CHAP; LL35lys) were selected for experimental studies. We hypothesized that (1) the proteins of interest will have the ability to degrade PG, and (2) the proteins will be potential antimicrobial agents against ESKAPE safe relatives. The results showed that LL35lys, Nb26lys and Tb42lys exhibit PG-degrading activity on zymography and hydrolysis assay. The enzymes (400 µg/mL) can reduce PG turbidity to 32-40%. The killing assay suggested that Tb42lys possess a boarder range (Escherichia coli, Pseudomonas putida, Acinetobacter baylyi and Klebsiella aerogenes). While Nb26lys can attack Gram-negative bacteria, LL35lys can only reduce the growth of the Gram-positive strains with an MIC90 of 2 …
Date: December 2023
Creator: Maneekul, Jindanuch
System: The UNT Digital Library
The Effects of Implementing a Reward-Based Version of Ostrom's Eight Design Principles as an Intervention Package on Responses in a Common Pool Resource (CPR) Game (open access)

The Effects of Implementing a Reward-Based Version of Ostrom's Eight Design Principles as an Intervention Package on Responses in a Common Pool Resource (CPR) Game

The aim of behavior analysis has always been to apply technologies rooted in basic behavioral principles to problems of societal importance (e.g., Skinner, 1948; 1953; 1987). One such problem is the Tragedy of the Commons - a phenomenon arising from systemic failures among a community, leading to the total collapse of a critical resource (Hardin, 1968). Elinor Ostrom's Eight Design Principles were developed to provide a framework for the self-management of common pool resources (CPRs; Ostrom, 1990/2015). When applied as an independently manipulated variable, Ostrom's design principles have shown strong effects in the management of CPRs within the context of a tabletop board game Catan® (Smith & Becker, 2023). This preparation included both rewards (i.e., positive reinforcement) and sanctions (i.e., positive punishment) as a feature of the independent variable. However, it has been well documented that punishing and coercive contingencies can lead to problematic outcomes for individuals and societies (e.g., Sidman, 2001; Skinner, 1976). This study evaluated the effects of utilizing only rewarding consequences in lieu of sanctions in an effort to produce the previously observed control over self-management of a CPR, utilizing the previously adapted rules of the Catan® board game.
Date: December 2023
Creator: Paterson, Ian Scott
System: The UNT Digital Library
The Effect of Restructuring of Peer Firms on Investment (open access)

The Effect of Restructuring of Peer Firms on Investment

Firms' operational restructuring involves information relevant to strategic choices as well as future demand and cost conditions. This study examines the relationship between peer firms' restructuring and a company's responsiveness to its growth opportunities. Peer firm restructuring can increase uncertainty with respect to a company's payoffs regarding its investment projects, leading to decreased responsiveness to growth opportunities. Using a large sample of public companies during 2006–2020, I find that peer firms' restructuring is negatively associated with the responsiveness of capital expenditures (Capex) to growth opportunities. The results suggest that peer firms' restructuring activities provide information about a company's investment projects above and beyond industry shocks reflected in changes in industry sales. Furthermore, these associations are moderated by industry competition. The negative effects of peer firms' restructuring on Capex sensitivity are the strongest in high-competition industries.
Date: December 2023
Creator: Kim, Hojoong
System: The UNT Digital Library
"Google is my friend": An Exploration of Older Adult Media Literacy (open access)

"Google is my friend": An Exploration of Older Adult Media Literacy

The advancement and incorporation of media in daily life continue to grow exponentially as the median age of humanity continues to rise. While there are media literacy education programs targeted toward children and adolescents, older adults are often left out of these initiatives. Based on ethnographic research conducted at two senior centers in Denton, TX, this thesis explores the way older adults analyze and interact with media. Data collection methods include participant observation and semi-structured interviews with senior center members over the age of 65. The research findings highlight how older adults navigate an expanding information society and how they lean on their community for support. These findings laid the foundation for the creation of a media literacy educational seminar given at both senior centers.
Date: December 2023
Creator: Williams, Mikaela Anne
System: The UNT Digital Library

Green Manufacturing of Lignocellulosic Fiber through Bacterial Degradation Process

Lignocellulose is the most abundant biopolymer on earth and offers excellent potential for sustainable manufacturing. Because lignocellulose is structurally complex and resistant to decomposition, innovative degradation strategies are necessary to unlock its value. In this dissertation, a green manufacturing process through enzyme-triggered self-cultured bacteria retting for lignocellulosic fiber was developed and investigated. The mechanism of the lignocellulosic fiber retting at a controlled degradation strategy was studied. This enzymatic degradation strategy utilizes a small amount of enzyme to trigger a large aggregation of specific bacteria to obtain clean fibers. Industrial hemp (Cannabis sativa L.) fiber was successfully retted with this strategy. The degradation of pectin was proved through an environmental scanning electron microscope and reducing sugar analysis. The bacterial successions were identified by 16S rRNA gene metagenomic sequencing. The results showed that Bacillaceae dominated the hemp retting conditions containing 1% pectinase, suggesting that pectinase can manipulate bacterial community succession by changing the nutrients available to bacteria through the degradation of pectin. This degradation strategy has 20-25% less environmental impact than the thermochemical degradation strategy, resulting in better fiber consistency and much shorter processing time (3-5 days) than the traditional water degradation strategy. The study on the degradation of lignin-rich lignocellulose also …
Date: December 2023
Creator: Fu, Yu
System: The UNT Digital Library
Saxophone Instruction by Women: Experiences of Achieving the Rank of Full Professor at Post-Secondary Institutions in the United States (open access)

Saxophone Instruction by Women: Experiences of Achieving the Rank of Full Professor at Post-Secondary Institutions in the United States

Since the first saxophone professor at the Paris Conservatory in 1858, saxophone instruction has primarily been a male-dominated field. Numerous sources detail the experiences, lives, and influence of male post-secondary saxophone instructors. Women have made great strides in the performance and instruction of the saxophone at the post-secondary level, but sources discussing their lives and experiences are limited. Saxophone instruction at the post-secondary level in the United States began in the late 1800s. As the instrument grew in popularity through the 20th century, more and more higher education institutions began incorporating the saxophone as an instrument for primary study. This increased the need for saxophone professors in the United States. In 1994, Elizabeth Zinn Ervin, became the first woman full professor. This was 40 years after the the first man, Larry Teal, held this rank. As of 2023, 15 women have achieved the rank of full professor. This document is intended to highlight several women saxophone instructors throughout the history of the instrument, and detail the thoughts and experiences of women saxophonists who have achieved the rank of full professor in the United States.
Date: December 2023
Creator: Heimann, Christa Marie
System: The UNT Digital Library

Mesenchymal Stem Cells Encapsulated and Aligned in Self-Assembling Peptide Hydrogels

This study presents a viable strategy using fmoc-protected peptides hydrogels, to encapsulate and stretch mesenchymal stem cells (MSC). To explore the peptide hydrogel potential, a custom mechanical stretching device with polydimethylsiloxane (PDMS) chambers were used to stretch MSCs encapsulated in Fmoc hydrogels. We investigated the impact of fmoc- FF prepared in dimethyl sulfoxide (DMSO), 1,1,1,3,3,3-hexafluoro-2-propanol (HFP) and deionizied water in the self-assembly, and mechanical properties of the gels. The peptide hydrogel is formed through molecular self-assembly of peptide sequence into β-sheets that are connected with the π-π aromatic stacking of F-F groups. The hydrogels provided a stiff, hydrated gel with round nanofiber morphology representing an elastic modulus of 174-266 KPa. MSCs cultured on peptide hydrogels undergo viability, morphology, and alignment evaluations using MTT, live/dead, and phalloidin (F-actin) staining. The F-actins of 3D- cultured MSCs in Fmoc-FF/HFP, and Fmoc-FF/DMSO followed by mechanical stretching showed elongated morphology with defined microfilament fibers compared to the round and spherical F-actin shape of the control cells. Peptide gels with 5mM concentration preserved 100% viability of MSC. Results reveals the feasibility and conditions for successful cell encapsulation and alignment within peptide hydrogels. Encapsulation of MSC in peptide nanofiber followed by a stretching process present a promising …
Date: December 2023
Creator: Kasani, Yashesh Varun
System: The UNT Digital Library

Factors Affecting MeHg Contamination of Spiders and Insect-Mediated MeHg Flux from Human-Made Ponds

The present study focused on methylmercury (MeHg) in emergent aquatic insects and spiders from human-made ponds. This dissertation addresses two main topics: (1) factors affecting variation in spider MeHg concentrations around human-made ponds and (2) the magnitude of MeHg transported out of human-made ponds by emergent aquatic insects (insect-mediated MeHg flux). Spiders were specifically targeted in this study because they have been proposed as sentinels of MeHg contamination (organism whose tissue concentrations reflect the level of MeHg in the environment). Spider MeHg concentrations were related to spider diet, size, and proximity to waterbody, but affected individual spider taxa differently. In a second study, I found that only "large" spiders within a taxa had tissue concentrations positively related to prey MeHg concentrations. These results indicate that the relationship between spider and prey MeHg could be size-dependent and that "large" spiders within a taxa may better reflect ambient MeHg contamination. Finally, I tested a conceptual model hypothesizing insect-mediated MeHg flux from human-made ponds is controlled by pond permanence and fish presence. In agreement with the conceptual model, insect-mediated MeHg flux from ponds was suppressed by the presence of fish, likely due to fish predation on emergent insect larvae. I found the mean …
Date: December 2023
Creator: Hannappel, Madeline Pratt
System: The UNT Digital Library
Cross-Pollinating Culturally Sustaining Pedagogies and Systemic Functional Linguistics in English as a Second Language (ESL) Classrooms (open access)

Cross-Pollinating Culturally Sustaining Pedagogies and Systemic Functional Linguistics in English as a Second Language (ESL) Classrooms

This exploratory case study research was conducted with a view to exploring how teachers teaching emergent bilingual students in ESL programs can enact the principles of culturally sustaining systematic functional linguistics (CS SFL), such as critical centering, historicizing, curricularizing, teaching and learning cycle (TLC), and semantic waving in their classrooms. Two middle school teachers participated in the study and used CS SFL principles to teach their emergent bilingual students. I gathered data for the study through non-participatory observations, semi-structured interviews, informal talks with the teachers, usually right after their classes, and artifacts from teachers and students. The thematic analysis of the data demonstrated that teachers could recognize their students' ways of knowing and being by (a) translanguaging between English and Spanish seamlessly in their classrooms; (b) centering their students' lifeways, prior knowledge, and lived experiences by making them the parts of their curricula; (c) using TLC for creating dialogic interactions between teachers and students and among students; (d) positioning their students through strength perspectives; and (e) using multimodal and multi-semiotic means of communication so that their students can understand their content area knowledge and express their ideas even if their English language is emerging. The teachers faced tensions about whether …
Date: December 2023
Creator: Rana, Lal Bahadur
System: The UNT Digital Library