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Developing a Phylogeny Based Machine Learning Algorithm for Metagenomics (open access)

Developing a Phylogeny Based Machine Learning Algorithm for Metagenomics

Metagenomics is the study of the totality of the complete genetic elements discovered from a defined environment. Different from traditional microbiology study, which only analyzes a small percent of microbes that could survive in laboratory, metagenomics allows researchers to get entire genetic information from all the samples in the communities. So metagenomics enables understanding of the target environments and the hidden relationships between bacteria and diseases. In order to efficiently analyze the metagenomics data, cutting-edge technologies for analyzing the relationships among microbes and communities are required. To overcome the challenges brought by rapid growth in metagenomics datasets, advances in novel methodologies for interpreting metagenomics data are clearly needed. The first two chapters of this dissertation summarize and compare the widely-used methods in metagenomics and integrate these methods into pipelines. Properly analyzing metagenomics data requires a variety of bioinformatcis and statistical approaches to deal with different situations. The raw reads from sequencing centers need to be processed and denoised by several steps and then be further interpreted by ecological and statistical analysis. So understanding these algorithms and combining different approaches could potentially reduce the influence of noises and biases at different steps. And an efficient and accurate pipeline is important to …
Date: August 2017
Creator: Rong, Ruichen
System: The UNT Digital Library
Developing a Self-Respect Instrument to Distinguish Self-Respect from Self-Esteem (open access)

Developing a Self-Respect Instrument to Distinguish Self-Respect from Self-Esteem

Throughout the scientific literature, researchers have referred to self-respect and self-esteem as being the same construct. However, the present study advocated that they exist as two distinct constructs. In this quantitative study, an instrument was developed to measure self-respect as a construct, and subsequently distinguish that self-respect is distinct from the construct of self-esteem. Exploratory factor analyses (EFA) indicated 32.60% of the variance was accounted for by the 11-item Jefferson Self-Respect instrument (JSR), which measured self-respect as a unidimensional construct. The reliability estimate of the scores from the JSR reached an acceptable α = .82. Fit indices (RMSEA = .031, SRMR = .037, CFI = .982, and TLI = .977) from the confirmatory factor analyses (CFA) signified a well-fitted hypothesized model of self-respect that existed as a unidimensional construct. Additionally, the CFA revealed that the construct of self-respect, and self-esteem was generally distinct, and the strength of the correlation between the two constructs was moderately positive (r = .62).
Date: August 2017
Creator: Jefferson, Sean G.
System: The UNT Digital Library
Developing Precipitation Hardenable High Entropy Alloys (open access)

Developing Precipitation Hardenable High Entropy Alloys

High entropy alloys (HEAs) is a concept wherein alloys are constructed with five or more elements mixed in equal proportions; these are also known as multi-principle elements (MPEs) or complex concentrated alloys (CCAs). This PhD thesis dissertation presents research conducted to develop precipitation-hardenable high entropy alloys using a much-studied fcc-based equi-atomic quaternary alloy (CoCrFeNi). Minor additions of aluminium make the alloy amenable for precipitating ordered intermetallic phases in an fcc matrix. Aluminum also affects grain growth kinetics and Hall-Petch hardenability. The use of a combinatorial approach for assessing composition-microstructure-property relationships in high entropy alloys, or more broadly in complex concentrated alloys; using laser deposited compositionally graded AlxCrCuFeNi2 (0 < x < 1.5) complex concentrated alloys as a candidate system. The composition gradient has been achieved from CrCuFeNi2 to Al1.5CrCuFeNi2 over a length of ~25 mm, deposited using the laser engineered net shaping process from a blend of elemental powders. With increasing Al content, there was a gradual change from an fcc-based microstructure (including the ordered L12 phase) to a bcc-based microstructure (including the ordered B2 phase), accompanied with a progressive increase in microhardness. Based on this combinatorial assessment, two promising fcc-based precipitation strengthened systems have been identified; Al0.3CuCrFeNi2 and Al0.3CoCrFeNi, …
Date: August 2017
Creator: Gwalani, Bharat
System: The UNT Digital Library
Development and Analysis of a Mobile Node Tracking Antenna Control System (open access)

Development and Analysis of a Mobile Node Tracking Antenna Control System

A wireless communication system allows two parties to exchange information over long distances. The antenna is the component of a wireless communication system that allows information to be converted into electromagnetic radiation that propagates through the air. A system using an antenna with a highly directional beam pattern allows for high power transmission and reception of data. For a directional antenna to serve its purpose, it must be accurately pointed at the object it is communicating with. To communicate with a mobile node, knowledge of the mobile node's position must be gained so the directional antenna can be regularly pointed toward the moving target. The Global Positioning System (GPS) provides an accurate source of three-dimensional position information for the mobile node. This thesis develops an antenna control station that uses GPS information to track a mobile node and point a directional antenna toward the mobile node. Analysis of the subsystems used and integrated system test results are provided to assess the viability of the antenna control station.
Date: August 2017
Creator: Hensley, Phillip H.
System: The UNT Digital Library
Development and Validation of Measures of Generalization of a Behavior Management Package (open access)

Development and Validation of Measures of Generalization of a Behavior Management Package

In order for the benefits of a behavior management skills training program to reach clients, caregivers must use the behavior management skills in the natural environment. The current study took place at a large residential facility for adults with disabilities, in which caregivers had received prior training in which they demonstrated behavior management skills and maintained those skills in contrived role plays. The current study represents a preliminary analysis of generalization of these skills in the natural environment; thus, a measurement system for when caregivers should demonstrate the tools was developed. The specific purpose of this study was to develop and evaluate a program to establish stimulus control over observers' measurement of appropriate behaviors. Researchers systematically developed and validated a measurement system of "good behaviors" that could be used across clients. The process of development and refinement of the measurement system is described. When the system was finalized, three observers' accuracy in using the system was assessed by comparing measured values to that of the code writer. Following feedback on individual instances of behavior, all observers scored the three target behaviors accurately. Ecological validity was assessed by surveying professionals at the facility and ecological validity results suggested a valid measurement …
Date: August 2017
Creator: Speckin, Lauren Marie
System: The UNT Digital Library
Development of a Natural Fiber Mat Plywood Composite (open access)

Development of a Natural Fiber Mat Plywood Composite

Natural fibers like kenaf, hemp, flax and sisal fiber are becoming alternatives to conventional petroleum fibers for many applications. One such applications is the use of Non-woven bio-fiber mats in the automobile and construction industries. Non-woven hemp fiber mats were used to manufacture plywood in order to optimize the plywood structure. Hemp fiber mats possess strong mechanical properties that comparable to synthetic fibers which include tensile strength and tensile modulus. This study focuses on the use of hemp fiber mat as a core layer in plywood sandwich composite. The optimization of fiber mat plywood was done by performing a three factor experiment. The three factors selected for this experiment were number of hemp mat layers in the core, mat treatment of the hemp mat, and the glue content in the core. From the analysis of all treatments it was determined that single hemp mat had the highest effect on improving the properties of the plywood structure.
Date: August 2017
Creator: Anthireddy, Prasanna Kumar
System: The UNT Digital Library
Development of a Targeted Protein Residue Analysis Approach in Archaeology (open access)

Development of a Targeted Protein Residue Analysis Approach in Archaeology

Liquid chromatography-mass spectrometry (LC-MS) based proteomic methods have provided archaeologists with a powerful tool for the discovery and identification of proteins within artifacts. Traditionally, discovery-based methods have utilized a non-targeted full mass scan method in an attempt to identify all proteins present within a given sample. However, increased sensitivity is often needed to target specific proteins in order to test hypotheses. Proteins present within archaeological materials present a unique challenge, as they are often subjected to a variety of chemical transformations both before and after burial. Any preserved proteins will be present within a complex mixture of compounds, and full mass scans often fail to detect less abundant proteins of interest. Consistent and reliable targeted methods are needed to detect protein biomarkers. Taphonomic experimentation was employed as a means to identify the effect of particular processes and conditions on the preservation of mare's milk proteins. In addition, three LC-MS methods were evaluated for their efficiency in identifying mare's milk-specific peptide biomarkers from experimental pottery samples. The ability to reliably detect the presence of these species-specific peptides can help provide evidence about past cultural groups, including the origins of dairying and animal domestication.
Date: August 2017
Creator: Scott, Ashley
System: The UNT Digital Library
Development of an Outcome Measure for Use in Psychology Training Clinics (open access)

Development of an Outcome Measure for Use in Psychology Training Clinics

The ability to monitor client change in psychotherapy over time is vital to quality assurance in service delivery as well as the continuing improvement of psychotherapy research. Unfortunately, there is not currently a comprehensive, affordable, and easily utilized outcome measure for psychotherapy specifically normed and standardized for use in psychology training clinics. The current study took the first steps in creating such an outcome measure. Following development of an item bank, factor analysis and item-response theory analyses were applied to data gathered from a stratified sample of university (n = 101) and community (n = 261) participants. The factor structure did not support a phase model conceptualization, but did reveal a structure consistent with the theoretical framework of the research domain criteria (RDoC). Suggestions for next steps in the measure development process are provided and implications discussed.
Date: May 2017
Creator: Davis, Elizabeth C.
System: The UNT Digital Library
Development of von Willebrand Factor Zebrafish Mutant Using CRISPR/Cas9 Mediated Genome Editing (open access)

Development of von Willebrand Factor Zebrafish Mutant Using CRISPR/Cas9 Mediated Genome Editing

von Willebrand factor (VWF) protein acts in the intrinsic coagulation pathway by stabilizing FVIII from proteolytic clearance and at the site of injury, by promoting the adhesion and aggregation of platelets to the exposed subendothelial wall. von Willebrand disease (VWD) results from quantitative and qualitative deficiencies in VWF protein. The variability expressivity in phenotype presentations is in partly caused by the action of modifier genes. Zebrafish has been used as hemostasis animal model. However, it has not been used to evaluate VWD. Here, we report the development of a heterozygote VWF mutant zebrafish using the genome editing CRISPR/Cas9 system to screen for modifier genes involved in VWD. We designed CRISPR oligonucleotides and inserted them into pT7-gRNa plasmid. We then prepared VWF gRNA along with the endonuclease Cas9 RNA from Cas9 plasmid. We injected these two RNAs into 1-4 cell-stage zebrafish embryos and induced a mutation in VWF exon 29 of the zebrafish with a mutagenesis rate of 16.6% (3/18 adult fish). Also, we observed a germline transmission with an efficiency rate of 5.5% (1/18 adult fish). We obtained a deletion in exon 29 which should result in truncated VWF protein.
Date: May 2017
Creator: Toffessi Tcheuyap, Vanina
System: The UNT Digital Library
Disease Tissue Imaging and Single Cell Analysis with Mass Spectrometry (open access)

Disease Tissue Imaging and Single Cell Analysis with Mass Spectrometry

Cells have been found to have an inherent heterogeneity that has led to an increase in the development of single-cell analysis methods to characterize the extent of heterogeneity that can be found in seemingly identical cells. With an understanding of normal cellular variability, the identification of disease induced cellular changes, known as biomarkers, may become more apparent and readily detectable. Biomarker discovery in single-cells is challenging and needs to focus on molecules that are abundant in cells. Lipids are widely abundant in cells and play active roles in cellular signaling, energy metabolism, and are the main component of cellular membranes. The regulation of lipid metabolism is often disrupted or lost during disease progression, especially in cancer, making them ideal candidates as biomarkers. Challenges exist in the analysis of lipids beyond those of single-cell analysis. Lipid extraction solvents must be compatible with the lipid or lipids of interest. Many lipids are isobaric making mass spectrometry analysis difficult without separations. Single-cell extractions using nanomanipulation coupled to mass spectrometry has shown to be an excellent method for lipid analysis of tissues and cell cultures. Extraction solvents are tunable for specific lipid classes, nanomanipulation prevents damage to neighboring cells, and lipid separations are possible …
Date: May 2017
Creator: Hamilton, Jason S.
System: The UNT Digital Library
"Don't Frack with Denton" (open access)

"Don't Frack with Denton"

Don't Frack With Denton chronicles the ground-breaking movement to ban hydraulic fracturing in the city of Denton, Texas by combining observational location shooting with extensive sit-down interviews and carefully negotiated subject-filmmaker relationships to create a safe and comfortable space for thoughtful reflection and criticism of a complex social movement who's activities span several years and many individuals. The result is a long-form documentary that is unapologetically in solidarity with this movement's goals while simultaneously maintaining enough editorial independence and critical distance to allow the activists themselves to honestly evaluate their decision-making, tactics and interpersonal relationships in ways that will provide insight and instruction to similar movements around the country and the world.
Date: May 2017
Creator: Graham, Garrett
System: The UNT Digital Library
Drum Music: A Performance Guide and Discussion of John Mackey's Influential Concerto for the Modern Percussionist (open access)

Drum Music: A Performance Guide and Discussion of John Mackey's Influential Concerto for the Modern Percussionist

John Mackey is an influential and prolific composer of wind band literature. His focus on and exploration of the percussion section are defining characteristics of his compositional voice. Mackey's concerto for percussion and wind band, "Drum Music," is a perfect example of his exploitation of the myriad timbres available within the percussion family, and also serves to showcase the versatility required of a modern percussionist. This dissertation and accompanying lecture recital provide a comprehensive guide for performers of the work. Major aspects of Mackey's compositional approach are discussed with emphasis placed on his use of percussion throughout his works. Analysis and performance concerns are discussed for each of the concertos three movements, and information is provided on the reduced version of the work prepared as part of this study.
Date: August 2017
Creator: McWilliams, Chris
System: The UNT Digital Library
Dynamic Screening via Intense Laser Radiation and Its Effects on Bulk and Surface Plasma Dispersion Relations (open access)

Dynamic Screening via Intense Laser Radiation and Its Effects on Bulk and Surface Plasma Dispersion Relations

Recent experimentation with excitation of surface plasmons on a gold film in the Kretschmann configuration have shown what appears to be a superconductive effect. Researchers claimed to see the existence of electron pairing during scattering as well as magnetic field repulsion while twisting the polarization of the laser. In an attempt to explain this, they pointed to a combination of electron-electron scattering in external fields as well as dynamic screening via intense laser radiation. This paper expands upon the latter, taking a look at the properties of a dynamic polarization function, its effects on bulk and surface plasmon dispersion relations, and its various consequences.
Date: August 2017
Creator: Lanier, Steven t
System: The UNT Digital Library
Economic Resilience, Disasters, and Green Jobs:  An Institutional Collective Action Framework (open access)

Economic Resilience, Disasters, and Green Jobs: An Institutional Collective Action Framework

This dissertation is about economic resilience of local governments to natural disasters. Specifically, the dissertation investigates resilience on regional level. Moreover, the dissertation also investigates growth in the green job sector in local governments. The findings indicate that local governments working with each other helps green job creation. In addition, the dissertation finds that green jobs, following disasters, experience three percent growth. This dissertation is important because it investigates the relationship between climate- related disasters and green jobs, which is an area that is under-investigated.
Date: December 2017
Creator: Ismayilov, Orkhan M.
System: The UNT Digital Library
Educational Technology: A Comparison of Ten Academic Journals and the New Media Consortium Horizon Reports for the Period of 2000-2017 (open access)

Educational Technology: A Comparison of Ten Academic Journals and the New Media Consortium Horizon Reports for the Period of 2000-2017

This exploratory and descriptive study provides an increased understanding of the topics being explored in both published research and industry reporting in the field of educational technology. Although literature in the field is plentiful, the task of synthesizing the information for practical use is a massive undertaking. Latent semantic analysis was used to review journal abstracts from ten highly respected journals and the New Media Consortium Horizon Reports to identify trends within the publications. As part of the analysis, 25 topics and technologies were identified in the combined corpus of academic journals and Horizon Reports. The journals tended to focus on pedagogical issues whereas the Horizon Reports tended to focus on technological aspects in education. In addition to differences between publication types, trends over time are also described. Findings may assist researchers, practitioners, administrators, and policy makers with decision-making in their respective educational areas.
Date: December 2017
Creator: Morel, Gwendolyn
System: The UNT Digital Library
Educational Uplift along the U.S.-Mexico Border: How Students, Families, and Educators Cultivate a College-Going Culture in Contested Terrain (open access)

Educational Uplift along the U.S.-Mexico Border: How Students, Families, and Educators Cultivate a College-Going Culture in Contested Terrain

Using critical race theory and LatCrit as conceptual frameworks, I conducted a qualitative instrumental case study of a cadre of self-identified Mexican-American and Hispanic college students who bring college knowledge, goodwill, and aid to their border town communities. The purpose of this study was to explore how college knowledge and other forms of academic capital are transmitted and co-constructed in the contested terrain of the borderlands. Primary data sources included semi-structured interviews, participant and non-participant observation, and personal artifacts (e.g. newspaper articles, college admissions essays, social media, etc.) collected from 17 full-time undergraduate student participants, 11 males and 6 females, ranging from 19 to 22 years old, who were active members of the Gates Millennium Scholars Program. Supplemental data sources included semi-structured interviews with 23 family members and 9 educators identified by student participants, as well as a review of public records regarding student participant's border town communities (e.g. newspaper articles, census data, educational statistics, etc.). Findings detail how this group of college students manages the 'scholar' distinction in their hometown and utilizes distinct methods to promote academic capital formation. Specifically, this study delineates the following four types of scholars: (1) pioneers, (2) guardians, (3) ambassadors, and (4) advocates. Ultimately, …
Date: August 2017
Creator: Sanchez, Nydia C
System: The UNT Digital Library
EEG Signal Analysis in Decision Making (open access)

EEG Signal Analysis in Decision Making

Decision making can be a complicated process involving perception of the present situation, past experience and knowledge necessary to foresee a better future. This cognitive process is one of the essential human ability that is required from everyday walk of life to making major life choices. Although it may seem ambiguous to translate such a primitive process into quantifiable science, the goal of this thesis is to break it down to signal processing and quantifying the thought process with prominence of EEG signal power variance. This paper will discuss the cognitive science, the signal processing of brain signals and how brain activity can be quantifiable through data analysis. An experiment is analyzed in this thesis to provide evidence that theta frequency band activity is associated with stress and stress is negatively correlated with concentration and problem solving, therefore hindering decision making skill. From the results of the experiment, it is seen that theta is negatively correlated to delta and beta frequency band activity, thus establishing the fact that stress affects internal focus while carrying out a task.
Date: May 2017
Creator: Salma, Nabila
System: The UNT Digital Library
The Effect of a Change Facilitator on Project-Based Learning Curriculum Design (open access)

The Effect of a Change Facilitator on Project-Based Learning Curriculum Design

This study sought to understand concerns and levels of use of a group of teachers in the process of developing a project-based learning (PBL) program, and the effect of a change facilitator on these processes. The research was guided by the following research questions: One, what are the concerns of teachers regarding the planning of a PBL curriculum? Two, what are the levels of use of teachers in the process of planning the PBL curriculum? Three, how does a change facilitator affect the process of change in the planning of a PBL curriculum? The population of this study consisted of seven subject area high school teachers and one district level administrative staff member. This study used the concerns-based adoption model (CBAM) to study the PBL innovation. CBAM is a conceptual framework that describes, explains, and predicts teachers' concerns and behaviors throughout the change process in education. In this study, the teachers progressed through the levels of use on a timeline at a rate that was much more rapid that what is typical for implementation of an innovation in an educational setting. This rapid progression was the function of the teacher population studied and the change facilitator that led the PBL …
Date: May 2017
Creator: Fry, Jana
System: The UNT Digital Library
Effect of Child Parent Relationship Therapy (CPRT) with Adoptive Parents of Preadolescents: A Pilot Study (open access)

Effect of Child Parent Relationship Therapy (CPRT) with Adoptive Parents of Preadolescents: A Pilot Study

Older adopted children and their families often express high need for support for attachment and trauma related concerns. Post-adoption mental health intervention focused on enhancing the parent-child relationship among adoptive parents and adoptees is essential for fostering placement permanency among these families. This single group pilot study explored the effect of Child-Parent Relationship Therapy (CPRT) for adoptive parents of preadolescents who reported attachment related concerns, stress in the parent-child relationship, and child behavior problems. Participants were 11 adoptive parents ages 25 to 64 (55% male; 91% couples; 100% married; 56% European American, 27% Asian, 9% Hispanic, and 9% Black American) with adoptees between the ages of 8 to 14 (56% male; 56% Hispanic, 33% European American, and 11% Black American). All child participants were adopted out of foster care. Data was collected at baseline, pretest, midtest, and posttest. Results from non-parametric Friedman test of differences across 4 points of measure indicated that CPRT demonstrated statistically significant improvement for the 3 outcome variables: parental empathy, child behavior, and parent child relationship stress. Specifically, results indicated that prior to receiving CPRT (baseline to pretest), parents demonstrated no change or worsening in functioning across all variables, whereas during the intervention phase findings showed …
Date: December 2017
Creator: Swan, Alyssa
System: The UNT Digital Library
The Effect of Instructional Expenditures on College Readiness (open access)

The Effect of Instructional Expenditures on College Readiness

With limited state and local funds as well as a growing student population, how elected decision makers allocate money to impact college readiness needs to be explored. The purpose of this research study was to explore the impact of instructional expenditures on educational outcomes. This multivariate multiple regression study specifically explored the impact of instructional expenditure ratios and per pupil instructional expenditures of every public school district in Texas on student performance college readiness indicators measured by state assessments (State of Texas Assessment of Academic Readiness [STAAR] Mathematics and English Language Arts [ELA] test scores) and national assessments (American College Test [ACT] and Scholastic Assessment Test [SAT] scores) over a 5-year period. Fifteen different regression models were established with various significant predictors of expenditures and revenue funds. These models explained up to 46% of the variance for college readiness scores over the 5-year period.
Date: August 2017
Creator: Blair, Cody
System: The UNT Digital Library
Effect of Surface Treatment on the Performance of CARALL, Carbon Fiber Reinforced Aluminum Dissimilar Material Joints (open access)

Effect of Surface Treatment on the Performance of CARALL, Carbon Fiber Reinforced Aluminum Dissimilar Material Joints

Fiber-metal laminates (FML) are the advanced materials that are developed to improve the high performance of lightweight structures that are rapidly becoming a superior substitute for metal structures. The reasons behind their emerging usage are the mechanical properties without a compromise in weight other than the traditional metals. The bond remains a concern. This thesis reviews the effect of pre-treatments, say heat, P2 etch and laser treatments on the substrate which modifies the surface composition/roughness to impact the bond strength. The constituents that make up the FMLs in our present study are the Aluminum 2024 alloy as the substrate and the carbon fiber prepregs are the fibers. These composite samples are manufactured in a compression molding process after each pre-treatment and are then subjected to different tests to investigate its properties in tension, compression, flexural and lap shear strength. The results indicate that heat treatment adversely affects properties of the metal and the joint while laser treatments provide the best bond and joint strength.
Date: August 2017
Creator: Bandi, Raghava
System: The UNT Digital Library
Effectiveness of Fillers for Corrosion Protection of AISI-SAE 1018 Steel in Sea Salt Solution (open access)

Effectiveness of Fillers for Corrosion Protection of AISI-SAE 1018 Steel in Sea Salt Solution

Corrosion represents the single most frequent cause for product replacement or loss of product functionality with a 5% coat to the industrial revenue generation of any country in this dissertation the efficacy of using filled coatings as a protection coating are investigated. Fillers disrupt the polymer-substrate coating interfacial area and lead to poor adhesion. Conflicting benefits of increasing surface hardness and corrosion with long term durability through loss of adhesion to the substrate are investigated. The effects of filler type, filler concentration and exposure to harsh environments such as supercritical carbon dioxide on salt water corrosion are systematically investigated. The constants maintained in the design of experiments were the substrate, AISI-SAE 1018 steel substrate, and the corrosive fluid synthetic sea salt solution (4.2 wt%) and the polymer, Bismaleimide (BMI). Adhesion strength through pull-off, lap shear and shear peel tests were determined. Corrosion using Tafel plots and electrochemical impedance spectroscopy was conducted. Vickers hardness was used to determine mechanical strength of the coatings. SEM and optical microscopy were used to examine dispersion and coating integrity. A comparison of fillers such as alumina, silica, hexagonal boron nitride, and organophilic montmorillonite clay (OMMT) at different concentrations revealed OMMT to be most effective with …
Date: May 2017
Creator: Al-Shenawa, Amaal
System: The UNT Digital Library
The Effectiveness of Hybrid Problem-Based Learning versus Manual-Based Learning in the Microbiology Laboratory (open access)

The Effectiveness of Hybrid Problem-Based Learning versus Manual-Based Learning in the Microbiology Laboratory

Promising results from the use of problem-based learning (PBL) as a teaching method in medical programs have encouraged many institutions to incorporate PBL into their curricula. This study investigates how applying hybrid-PBL (H-PBL) in a microbiology laboratory impacts students' higher-order thinking as compared to applying a lecture-based pedagogy. The experimental design compared the learning outcomes of two groups of students: the control group and the H-PBL group, for whom PBL cases comprised 30% of the curriculum. Both groups were taught basic skills for the microbiology lab by the same instructor. Using the traditional teaching style for the control group, the instructor offered each student what they needed for their experiments. The H-PBL group practiced experimental design, data analysis, theory proposal, and created research questions by using six study cases that were closely linked to the area of study. The outcome was measured using a pre- and post- assessment consisting of 24 questions that was designed by following Bloom's taxonomy of learning levels. A one-way ANOVA was used to analyze the data. The results showed that for the first three levels of Bloom's taxonomy— knowledge, comprehension, and application—there were no statistically significant differences between the H-PBL and control group gain scores …
Date: May 2017
Creator: Alharbi, Najwa
System: The UNT Digital Library
The Effectiveness of Peer Mentoring with High School Student Mentors and Child Mentees (open access)

The Effectiveness of Peer Mentoring with High School Student Mentors and Child Mentees

This randomized, controlled study examined the effectiveness of two mentoring programs, child mentor relationship training (CMRT) and peer assistance and leadership (PAL®), on high school mentor empathic behaviors and child mentee behavior problems. Participants were 60 young, at-risk students (61.7% male; 38.3% Hispanic/Latino/a, 31.7% Caucasian, 21.7% African American, 8.3% biracial) and 30 high school students (53.3% male; 66.7% Caucasian, 26.7% Hispanic/Latino/a, 0.03% African American, 0.03% Asian). Mentors and mentees were randomly assigned to CMRT or PAL®, which was treatment as usual in the participating school district. Results from 2 (group) by 2 (time) repeated measures ANOVAs indicated compared to the PAL® treatment group over time, mentors in the CMRT group demonstrated statistically significant improvement in empathic behaviors with a large treatment effect, as rated by independent observers. Analysis revealed a moderate treatment effect with CMRT group mentee behavior problems, but the difference was not statistically significant between treatment groups over time. Further analysis revealed the CMRT group demonstrated statistically significant reductions in behavior problems from pre- to post-test with a very large treatment effect. Overall, findings support CMRT as a promising school-based intervention for at-risk young children that potentially increases school counselor efficiency.
Date: December 2017
Creator: Dafoe, Eric C.
System: The UNT Digital Library