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Detection of Temporal Events and Abnormal Images for Quality Analysis in Endoscopy Videos (open access)

Detection of Temporal Events and Abnormal Images for Quality Analysis in Endoscopy Videos

Recent reports suggest that measuring the objective quality is very essential towards the success of colonoscopy. Several quality indicators (i.e. metrics) proposed in recent studies are implemented in software systems that compute real-time quality scores for routine screening colonoscopy. Most quality metrics are derived based on various temporal events occurred during the colonoscopy procedure. The location of the phase boundary between the insertion and the withdrawal phases and the amount of circumferential inspection are two such important temporal events. These two temporal events can be determined by analyzing various camera motions of the colonoscope. This dissertation put forward a novel method to estimate X, Y and Z directional motions of the colonoscope using motion vector templates. Since abnormalities of a WCE or a colonoscopy video can be found in a small number of frames (around 5% out of total frames), it is very helpful if a computer system can decide whether a frame has any mucosal abnormalities. Also, the number of detected abnormal lesions during a procedure is used as a quality indicator. Majority of the existing abnormal detection methods focus on detecting only one type of abnormality or the overall accuracies are somewhat low if the method tries to …
Date: August 2013
Creator: Nawarathna, Ruwan D.
System: The UNT Digital Library
Determinacy-related Consequences on Limit Superiors (open access)

Determinacy-related Consequences on Limit Superiors

Laczkovich proved from ZF that, given a countable sequence of Borel sets on a perfect Polish space, if the limit superior along every subsequence was uncountable, then there was a particular subsequence whose intersection actually contained a perfect subset. Komjath later expanded the result to hold for analytic sets. In this paper, by adding AD and sometimes V=L(R) to our assumptions, we will extend the result further. This generalization will include the increasing of the length of the sequence to certain uncountable regular cardinals as well as removing any descriptive requirements on the sets.
Date: May 2013
Creator: Walker, Daniel
System: The UNT Digital Library
Determinants of the Applications to the Institutional Care in Turkey: Darulaceze Example (open access)

Determinants of the Applications to the Institutional Care in Turkey: Darulaceze Example

Although institutional care has started to be outmoded in the developed countries with development of different models of care, it still has a considerable place in the developing countries such as Turkey. This is because, changes in the demographic structure, extended family, and urban development of Turkey has brought about several aging problems leading older adults to end up in institutions. Loneliness was one of the significant reasons given in the Social Inquiry Survey of Applicants of Darulaceze Old-Age Institution and the basis for a micro level analysis in this study. Therefore, the main objective of the study was to determine the predictors of loneliness, including age, the state of living alone, functional independence, education, and gender. Analysis of the results indicated that these predictors have significant effects on the loneliness predominantly defined by social factors rather than medical factors. In addition, the meso and macro level analyses were employed to control the micro level analysis and see a general picture of institutional care. Thus, an academic example of diagnosing the main reasons behind the institutional care was presented to understand the context of aging in Turkey.
Date: May 2013
Creator: Esendemir, Serif
System: The UNT Digital Library
Development of a Differential Neurocognitive Profile for Alzheimer’s Dementia and Vascular Dementia (open access)

Development of a Differential Neurocognitive Profile for Alzheimer’s Dementia and Vascular Dementia

Alzheimer’s Dementia (AD) is among the most common diseases in the Geriatric population, and its prevalence is expected to quadruple by 2047.Vascular Dementia (VaD) is the second most frequent cause of dementia, with studies indicating VaD accounts for 10-20% of dementia cases across the globe. A diagnostic model differentiating AD and VaD would be clinically and scientifically valuable, considering the treatment approaches for these conditions are different. Although there are differences between AD and VaD on their neuropsychological profiles, a diagnostic model that successfully differentiates AD and VaD on neuropsychological testing has not been developed, despite previous attempts. Our study addresses this gap in the literature by examining two diagnostic models used to predict the conversion of AD from mild cognitive impairment, and a third model was proposed to differentiate AD from VaD. We conducted ROC Analyses using the variables LM II Standard Score, Animals Total, and CDRS Sum based on a previous diagnostic model. The sensitivity and specificity for the diagnosis of mild VaD were calculated for all possible scores of each test measure. The Animals Total cutoff score of 7 achieved excellent sensitivity and specificity, receiving 96% and 92%, respectively. In this sample, patients who could name at …
Date: August 2013
Creator: Hill, Jonathan
System: The UNT Digital Library
Development of Enabling Technologies to Visualize the Plant Lipidome (open access)

Development of Enabling Technologies to Visualize the Plant Lipidome

Improvements in mass spectrometry (MS)-based strategies for characterizing the plant lipidome through quantitative and qualitative approaches such as shotgun lipidomics have substantially enhanced our understanding of the structural diversity and functional complexity of plant lipids. However, most of these approaches require chemical extractions that result in the loss of the original spatial context and cellular compartmentation for these compounds. To address this current limitation, several technologies were developed to visualize lipids in situ with detailed chemical information. A subcellular visualization approach, direct organelle MS, was developed for directly sampling and analyzing the triacylglycerol contents within purified lipid droplets (LDs) at the level of a single LD. Sampling of single LDs demonstrated seed lipid droplet-to-droplet variability in triacylglycerol (TAG) composition suggesting that there may be substantial variation in the intracellular packaging process for neutral lipids in plant tissues. A cellular and tissue visualization approach, MS imaging, was implemented and enhanced for visualizing the lipid distributions in oilseeds. In mature cotton seed embryos distributions of storage lipids (TAGs) and their phosphatidylcholine (PCs) precursors were distribution heterogeneous between the cotyledons and embryonic axis raising new questions about extent and regulation of oilseed heterogeneity. Extension of this methodology provides an avenue for understanding metabolism …
Date: August 2013
Creator: Horn, Patrick J.
System: The UNT Digital Library
Development of Novel Semi-conducting Ortho-carborane Based Polymer Films: Enhanced Electronic and Chemical Properties (open access)

Development of Novel Semi-conducting Ortho-carborane Based Polymer Films: Enhanced Electronic and Chemical Properties

A novel class of semi-conducting ortho-carborane (B10C2H12) based polymer films with enhanced electronic and chemical properties has been developed. The novel films are formed from electron-beam cross-linking of condensed B10C2H12 and B10C2H12 co-condensed with aromatic linking units (Y) (Y=1,4-diaminobenzene (DAB), benzene (BNZ) and pyridine (PY)) at 110 K. The bonding and electronic properties of the novel films were investigated using X-ray photoelectron spectroscopy (XPS), UV photoelectron spectroscopy (UPS) and Mulliken charge analysis using density functional theory (DFT). These films exhibit site-specific cross-linking with bonding, in the pure B10C2HX films, occurring at B sites non-adjacent to C in the B10C2H12 icosahedra. The B10C2H12:Y films exhibit the same phenomena, with cross-linking that creates bonds primarily between B sites non-adjacent to C in the B10C2H12 icosahedra to C sites in the Y linking units. These novel B10C2HX: Y linked films exhibit significantly different electron structure when compared to pure B10C2HX films as seen in the UPS spectra. The valence band maxima (VBM) shift from - 4.3 eV below the Fermi level for pure B10C2HX to -2.6, -2.2, and -1.7 for B10C2HX:BNZ, B10C2HX:PY, and B10C2HX:DAB, respectively. The top of the valence band is composed of states derived primarily from the Y linking units, suggesting …
Date: August 2013
Creator: Pasquale, Frank L.
System: The UNT Digital Library
Development of the Knowledge and Attitudes Toward Near-death Experiences Scale (open access)

Development of the Knowledge and Attitudes Toward Near-death Experiences Scale

The purpose of this study was to develop an instrument to measure healthcare professionals’ knowledge and attitudes about near-death experiences (NDEs) that would demonstrate acceptable psychometric properties. In consultation with a focus group of six NDE experts, I developed the 50-item Knowledge and Attitudes toward Near-Death Experiences Scale (KANDES), including the 24-item KANDES–Attitude subscale (KANDES-A) and the 26-item KANDES–Knowledge subscale (KANDES-K). Including a pilot administration in which feedback indicated no need for revision, a total of 256 professional and student counselors completed the KANDES. Separate reliability and validity analyses were conducted for each subscale. For the KANDES–A, Cronbach’s alpha was .909, and Pearson’s r for test-retest was .748, both indicating acceptable reliability. An exploratory factor analysis indicated four factors to retain and yielded a factor solution that explained 54.87% of the variance, an acceptable amount of variance to substantiate construct validity. For the KANDES–K, Cronbach’s alpha was .816, indicating acceptable reliability. For each of the scale’s three domains, Cronbach’s alpha was .816 for Domain 1: NDE Content, .817 for Domain 2: NDE Aftereffects, and .631 for Domain 3: Experiencer Characteristics, indicating acceptable reliability. Pearson’s r for test-retest on the total KANDES–K was .812, further demonstrating acceptable reliability.
Date: August 2013
Creator: Pace, Laura
System: The UNT Digital Library
Diaspora Philanthropy: Identity and Obligation Among Indian Engineers in the United States (open access)

Diaspora Philanthropy: Identity and Obligation Among Indian Engineers in the United States

Diaspora philanthropy to India has grown rapidly over the past several decades. However, little is known about the motivations of Indians living in the U.S. to donate philanthropically to India. Extant studies have either focused on quantitative analysis of diaspora philanthropy or qualitative research on the receiving of diaspora philanthropy in India. The motivations and strategies of the Indian diaspora in the U.S. have not been explored, particularly, the informal mechanisms and strategies of making philanthropic donations to India and the obligations that underlie the practice of diaspora philanthropy remain neglected in the existing studies on diaspora philanthropy. My research addressed this gap in the existing literature on diaspora philanthropy by conducting qualitative face-to-face in-depth interviews with a snowball sample of 25 Indian engineers in San Diego, California. In my study, it was found that Indians preferred to channel funds for philanthropy in India through friends and family because of lack of trust in formal organizations and greater confidence in the activities of friends and family in India due to familiarity and better accountability. It was also found that Indians felt indebted to Indian society and the Indian nation-state for the free and subsidized education they had received in India, …
Date: December 2013
Creator: Batra, Shikha
System: The UNT Digital Library
The Disney Influence on Kindergarten Girls' Body Image (open access)

The Disney Influence on Kindergarten Girls' Body Image

Media is now a part of the early childhood world. In many countries, including industrialized and developing countries, children spend more time consuming various kinds of media. The impact of media on children's perception of their body images has been and continues to be a concern of parents and early childhood professionals. This research examined the influence of Disney movies on Thai kindergarten girls' body images and self-esteem. Thai kindergarten girls completed three measures of body self-image: the Body Figure Preference Scale, the Body Esteem Scale, and the Self-Esteem Scale. The girl participants were randomly assigned to two groups: focused on a female theme (FFT) and focused on a non-human theme (FNT). The experimental group viewed "female" Disney movie themes, while the control group viewed "animal" Disney movie themes. Girls in the experimental group expressed greater body image dissatisfaction scores after watching Disney movies, which was an expected finding. Results from the present study suggest that girls in both groups become concerned about their body esteem after video exposure. However, there was no significant difference in self-esteem between girls in FFT and FNT. In summary, the findings of this study support the belief that Disney movies influence young girls' perceptions …
Date: May 2013
Creator: Asawarachan, Tanawan
System: The UNT Digital Library
Doctoral Level Counseling Students’ Experiences and Perceptions of Learning in a Cohort Environment (open access)

Doctoral Level Counseling Students’ Experiences and Perceptions of Learning in a Cohort Environment

Learning community literature supports the use of student cohorts to enhance learning through increased peer interaction and common course work. Researchers employed the qualitative method of phenomenography to identify various ways doctoral counseling students conceptualize and experience learning in a cohort over the course of a single academic year. Participants were all 10 members of a single southwestern U.S. university counseling program doctoral cohort of full-time students between 20 and 59 years of age with 5 members 20-29, 4 members 30-39, 1 member 50-59; 8 female, 2 male; 9 White non-Hispanic, 1 African-American. Data were transcripts from 30 one-hour interviews, three for each participant over the course of their first year of study. The research team that analyzed the data consisted of three advanced counseling program doctoral students, each with research methods coursework. Results revealed nine dynamic structural aspects of learning: dialogue, diversity, knowledge, motivation, support, shared experience, relationship development, interpersonal awareness, and conflict. Findings support the use of learning communities in doctoral level counselor education programs. Cohort members demonstrated increasing awareness of the potential learning benefits of cohort interaction and developed more in depth strategies over time to utilize the cohort to enhance learning. Future counselor educators may now …
Date: August 2013
Creator: Huffman, David D.
System: The UNT Digital Library
Drilling Down Natural Gas Well Permitting Policy:  Examining the Effects of Institutional Arrangements on Citizen Participation and Policy Outcomes (open access)

Drilling Down Natural Gas Well Permitting Policy: Examining the Effects of Institutional Arrangements on Citizen Participation and Policy Outcomes

Over the past decade the movement of natural gas drilling operations toward more suburban and urban communities has created unique policy challenges for municipalities. Municipal response is manifest in a variety of institutional arrangements, some more enabling than others regarding citizen access to public hearings. This observation lead to the main research question, “How are variations in citizen participation affecting policy outcomes?” The argument is made that institutions affecting citizen participation, in turn affect policy outcomes. If the general public is given access to public hearings, their preferences for longer setbacks will be taken into account and the approved gas wells will have greater distances from neighboring residences – effectively providing for greater safety. Given the paucity of research on the topic of natural gas drilling, the research first begins with the presentation of a theoretical framework to allow for analysis of the highly complex topic of gas well permitting, emphasizing the rule-ordered relationships between the various levels of decision making and provides a typology of collective action arenas currently used by Texas municipalities. The research uses paired case studies of most similar design and employs a mixed methods process for the collection, analysis and interpretation of the municipal level …
Date: August 2013
Creator: Long, Laurie C.
System: The UNT Digital Library
Dynamic Adhesion and Self-cleaning Mechanisms of Gecko Setae and Spatulae (open access)

Dynamic Adhesion and Self-cleaning Mechanisms of Gecko Setae and Spatulae

Geckos can freely climb on walls and ceilings against their body weight at speed of over 1ms-1. Switching between attachment and detachment seem simple and easy for geckos, without considering the surface to be dry or wet, smooth or rough, dirty or clean. In addition, gecko can shed dirt particles during use, keeping the adhesive pads clean. Mimicking this biological system can lead to a new class of dry adhesives for various applications. However, gecko’s unique dry self-cleaning mechanism remains unknown, which impedes the development of self-cleaning dry adhesives. In this dissertation we provide new evidence and self-cleaning mechanism to explain how gecko shed particles and keep its sticky feet clean. First we studied the dynamic enhancement observed between micro-sized particles and substrate under dry and wet conditions. The adhesion force of soft (polystyrene) and hard (SiO2 and Al2O3) micro-particles on soft (polystyrene) and hard (fused silica and sapphire) substrates was measured using an atomic force microscope (AFM) with retraction (z-piezo) speed ranging over 4 orders of magnitude. The adhesion is strongly enhanced by the dynamic effect. When the retraction speeds varies from 0.02 µm/s to 156 µm/s, the adhesion force increases by 10% ~ 50% in dry nitrogen while …
Date: December 2013
Creator: Xu, Quan
System: The UNT Digital Library
Educational Experiences of Youth with And/or At-risk for Emotional and Behavioral Disorders Residing in Foster Care Settings (open access)

Educational Experiences of Youth with And/or At-risk for Emotional and Behavioral Disorders Residing in Foster Care Settings

Research examining the academic experiences of youth with emotional and behavioral disorders (EBD) residing in foster care (FC) is scarce. Research is warranted to understand the academic strengths, weaknesses, and school disciplinary experiences of youth with EBD residing in FC. Data from the National Survey of Child and Adolescent Well-being II (NSCAW II) included data on eight participants classified as EBD. Having a limited number of participants classified as EBD in the data set, I used participants’ scores on the Child Behavior Checklist (CBCL) to classify participants who may be at-risk for EBD. Analyses were conducted to determine if significant relationships existed between participants’ internalizing and externalizing scores on the CBCL and their (a) scores on assessments of academic achievement and (b) behavior problems leading to suspension or expulsion. Results indicated that participants’ scores on the CBCL were not predictive of their academic achievement or of their numbers of behavior problems leading to suspension or expulsion.
Date: August 2013
Creator: Lewis, Calli G.
System: The UNT Digital Library
The Effect of Group Status on Moral Relativism and the Stigmatization of Mental Illness: a Social Dominance Theoretical Model (open access)

The Effect of Group Status on Moral Relativism and the Stigmatization of Mental Illness: a Social Dominance Theoretical Model

This dissertation created a model to explore the effect of dominant group status on stigmatization of mental illness and on moral relativism and the interactive effect of dominant group status on stigmatization of mental illness through moral relativism. The model was conceptualized according to social dominance theory. Latent variables were created to measure moral relativism and stigmatization of mental illness. The latent measures were conceptualized according to current theories in the fields of moral relativism and stigmatization. During statistical analyses the latent measure for moral relativism was found to be unreliable. The study then became confirmatory-exploratory in nature by first comparing the fit indices of three alternate models with single-measure latent variables. The model that best fit the data was then used to conclude the exploratory research on the effect of group status on moral relativism and stigmatization of mental illness. The model was not supported by the data based on fit index and standardized residual scores.
Date: May 2013
Creator: Cincotta, Julie Passmore
System: The UNT Digital Library
The Effect of Head Flexion/extension on Acoustic Measures of Singing Voice Quality (open access)

The Effect of Head Flexion/extension on Acoustic Measures of Singing Voice Quality

A study was undertaken to identify the effect of head flexion/extension on singing voice quality. The amplitude of the fundamental frequency (F0), and the singing power ratio (SPR), an indirect measure of singer’s formant activity, were measured. F0 and SPR scores at four experimental head positions were compared with the subjects’ scores at their habitual positions. Three vowels and three pitch levels were tested. F0 amplitudes and low frequency partials in general were greater with more extended head positions, while SPR increased with neck flexion. No effect of pitch or vowel was found. Gains in SPR appear to be the result of damping low frequency partials rather than amplifying those in the singer’s formant region. Raising the amplitude of F0 is an important resonance tool for female voices in the high range, and may be of benefit to other voice types in resonance, loudness, and laryngeal function.
Date: August 2013
Creator: Knight, Elizabeth Johnson
System: The UNT Digital Library
The Effect of It Process Support, Process Visualization and Process Characteristics on Process Outcomes (open access)

The Effect of It Process Support, Process Visualization and Process Characteristics on Process Outcomes

Business process re-engineering (part of the Business Process Management domain) is among the top three concerns of Information Technology (IT) leaders and is deemed to be one of many important IT leveraging opportunities. Two major challenges have been identified in relation to BPM and the use of IT. The first challenge is related to involving business process participants in process improvement initiatives using BPM systems. BPM technologies are considered to be primarily targeted for developers and not BPM users, and the need to engage process participants into process improvement initiatives is not addressed, contributing to the business-IT gap. The second challenge is related to potential de-skilling of knowledge workers when knowledge-intensive processes are automated and process knowledge resides in IT, rather than human process participants. The two identified challenges are not separate issues. Process participants need to be knowledgeable about the process in order to actively contribute to BPM initiatives, and the loss of process knowledge as a result of passive use of automated systems may further threaten their participation in process improvement. In response to the call for more research on the individual impacts of business process initiatives, the purpose of this dissertation study is to understand the relationship …
Date: December 2013
Creator: Al Beayeyz, Alaa
System: The UNT Digital Library
The Effect of Stock Splits on Small, Medium, and Large-sized Firms Before and After Decimalization (open access)

The Effect of Stock Splits on Small, Medium, and Large-sized Firms Before and After Decimalization

This study examines the impact of reducing tick size and, in particular decimalization on stock splits. Based on previous studies, this study examines hypotheses in the following three areas: first, market reaction around stock split announcement and ex-dates, second, the effect of tick size on liquidity after stock split ex-dates, and third, the effect of tick size on return volatility after stock split ex-dates. The impact of tick size on market reaction around split announcement and ex-dates is measured by abnormal returns and buy and hold abnormal returns (BHARs). Also, this study investigates the long term impact of decimalization on market reaction for small, medium, and large firms for the three different tick size periods. The effect of tick size on liquidity after stock split ex-dates is measured by turnover, relative bid ask spread, and market maker count. The effect of tick size on return volatility around stock split announcement and ex-dates is measured by return standard deviation. Also, this study investigates the long term impact of decimalization on volatility after split ex-dates for small, medium, and large firms for three different tick size periods.
Date: December 2013
Creator: Jang, Seon Deog
System: The UNT Digital Library
Effects of a Brain Improvement Program on Students' Reading Achievement (open access)

Effects of a Brain Improvement Program on Students' Reading Achievement

How to close the reading achievement gap among K-12 students is an ongoing emphasis for educators in the 21st century. The purpose of the study was to determine if using kinesthetic movements from the Brain Gym® program improved the reading achievement of Grade 3 Hispanic and African American students. Students from four elementary schools participated in the study. The students in the control and experimental groups completed a 2004 release TAKS third grade reading assessment for the pretest and posttest. Students in the experimental group completed five selected kinesthetic movements from the Brain Gym® program five minutes at the beginning of each Monday through Friday school day. The intervention lasted 30 days and a total of 150 minutes. Data were analyzed using a 2 x 2 mixed between-within subjects analysis of variance. Findings revealed that performing the five kinesthetic movements from the Brain Gym® program did not increase students' reading achievement scores. Only the variable of time between pretest and posttest affected students' reading scores. The results from this study did not support the findings of other studies of the effectiveness of kinesthetic movements.
Date: May 2013
Creator: Sánchez, Edelmira
System: The UNT Digital Library
Effects of a Prototypical Training Program on the Implementation of Systematic Observational Data Collection on Iep Objectives for the Core Deficits of Autism Spectrum Disorders (open access)

Effects of a Prototypical Training Program on the Implementation of Systematic Observational Data Collection on Iep Objectives for the Core Deficits of Autism Spectrum Disorders

Legal mandates and best practice recommendations for the education of students with autism spectrum disorders (ASD) emphasize the importance of systematic, ongoing observational data collection in order to monitor progress and demonstrate accountability. The absence of such documentation in decision-making on instructional objectives indicates a weakness in bridging the research-to-practice gap in special education. Utilizing a multiple baseline design across participants, the current study evaluated the effects of a prototypical teacher training program (i.e., workshop, checklist, in-classroom training with feedback, and maintenance with a thinned schedule of feedback) on the frequency of data collection on core deficits of ASD and the use of data-based decision-making. Results indicate increases in daily mean frequency of data collection following intervention. Maintenance and generalization indicates variable responding across participants. Effect size (Cohen's d) indicates a large, clinically significant effect of the training program. Results are discussed in relation to training models, maintenance, and future research.
Date: May 2013
Creator: Harkins, Jessica L.
System: The UNT Digital Library
The Effects of Adlerian Play Therapy on Maladaptive Perfectionism and Anxiety and in Children (open access)

The Effects of Adlerian Play Therapy on Maladaptive Perfectionism and Anxiety and in Children

I used singlecase A-B-A experimental design to examine the effectiveness of Adlerian play therapy (AdPT) for children identified with clinical levels of perfectionism on the Conners Parent Rating Scale-Revised and Conners Teacher Rating Scale-Revised. Participants were 2 children, a 10 year-old Hispanic male and a 7 year-old Caucasian female. To examine the effect of AdPT on maladaptive perfectionism and anxiety, the Child-Adolescent Perfectionism Scale and the Revised Children’s Manifest Anxiety Scale were administered to the children twice weekly over 3 phases of the study: baseline (6 administrations), intervention (12-16 administrations), and maintenance (6 administrations) for a total of 24 to 29 data points. Additionally, parents and teachers completed the Conners Rating Scales-Revised5 times: (1) prior to study, (2) following baseline/prior to treatment, (3) midpoint of treatment, (4) following treatment, and (5) following maintenance phase.During the intervention phase, the male and female participants attended 21 and 16 play therapy sessions, their mothers attended 6 and 5 parent consultations, and their teachers attended 6 and 3 teacher consultations, respectively. Analysis of the child self-report assessments indicated mixed and inconclusive results regarding the effects of AdPT on target behaviors. However, results of the parent and teacher reports indicated clinically significant reductionsin maladaptive perfectionism …
Date: August 2013
Creator: Akay, Sinem
System: The UNT Digital Library
Effects of Natural/anthropogenic Stressors and a Chemical Contaminant on Pre and Post Mycorrhizal Colonization in Wetland Plants (open access)

Effects of Natural/anthropogenic Stressors and a Chemical Contaminant on Pre and Post Mycorrhizal Colonization in Wetland Plants

Arbuscular mycorrhizal fungi, colonizing over 80% of all plants, were long thought absent in wetlands; however, recent studies have shown many wetland plants harbor arbuscular mycorrhizae (AM) and dark septate endophytes (DSE). Wetland services such as biodiversity, shoreline stabilization, water purification, flood control, etc. have been estimated to have a global value of $14.9 trillion. Recognition of these vital services is accompanied by growing concern for their vulnerability and continued loss, which has resulted in an increased need to understand wetland plant communities and mycorrhizal symbiosis. Factors regulating AM and DSE colonization need to be better understood to predict plant community response and ultimately wetland functioning when confronting natural and human induced stressors. This study focused on the effects of water quality, hydrology, sedimentation, and hurricanes on AM and DSE colonization in three wetland species (Taxodium distichum, Panicum hemitomon, and Typhal domingensis) and plant communities of coastal wetlands in Southeast Louisiana and effects of an antimicrobial biocide, triclosan (TCS), on AM (Glomus intraradices) spore germination, hyphal growth, hyphal branching, and colonization in fresh water wetland plants (Eclipta prostrata, Hibiscus laevis, and Sesbania herbacea) from bottom land hardwood forest in north central Texas. The former, mesocosm studies simulating coastal marsh vegetation …
Date: August 2013
Creator: Twanabasu, Bishnu Ram
System: The UNT Digital Library
Effects of Problem-based Learning on a Fifth Grade Language Arts Classroom (open access)

Effects of Problem-based Learning on a Fifth Grade Language Arts Classroom

The main purpose of this qualitative research was to discover the effects of problem-based learning on a fifth grade language arts classroom. The secondary purpose was to examine how receptive fifth grade students were to a new way of learning. In this descriptive study, a group of nine students created an alternate reality game as part of a problem-based learning module. The instructional design of the study included three weeks for students to design and construct their games and one week to play, receive feedback and revise based on feedback. Through reflective blogs, semi-structured interviews, video recordings, and observations, data was collected to analyze. Over a period of five months, the data was coded and arranged into categories. The categories merged into themes. The results and findings revealed the impact collaborative groups have on design and enjoyment. Self-regulation skills were found to be lacking in most of the students, intrinsic motivation increased for some students while others developed positive outcomes beyond the scope of this study.
Date: May 2013
Creator: Blackwell, Deborah
System: The UNT Digital Library
Effects of Quantum Coherence and Interference (open access)

Effects of Quantum Coherence and Interference

Quantum coherence and interference (QCI) is a phenomenon that takes place in all multi-level atomic systems interacting with multiple lasers. In this work QCI is used to create several interesting effects like lasing without inversion (LWI), controlling group velocity of light to extreme values, controlling the direction of propagation through non-linear phase matching condition and for controlling the correlations in field fluctuations. Controlling group velocity of light is very interesting because of many novel applications it can offer. One of the unsolved problems in this area is to achieve a slow and fast light which can be tuned continuously as a function of frequency. We describe a method for creation of tunable slow and fast light by controlling intensity of incident laser fields using QCI effects. Lasers are not new to the modern world but an extreme ultra-violet laser or a x-ray laser is definitely one of the most desirable technologies today. Using QCI, we describe a method to realize lasing at high frequencies by creating lasing without inversion. Role of QCI in creating correlations and anti-correlations, which are generated by vacuum fluctuations, in a three level lambda system coupled to two strong fields is discussed.
Date: August 2013
Creator: Davuluri, Subrahmanya Bhima Sankar
System: The UNT Digital Library
The Effects of the Texas Reading First Response to Intervention Program on Student Achievement and Campus Special Education Rates (open access)

The Effects of the Texas Reading First Response to Intervention Program on Student Achievement and Campus Special Education Rates

The purpose of this study was to examine special education populations, special education reading achievement, and regular education reading achievement in relation to the implementation of the Reading First three-tiered model as a response to Intervention platform. The population for this study focused on rural schools with Grades K-3 in attendance. Schools participated in the reading first grant period of the 2003-2009 school years. Forty-seven Texas Reading First schools were compared to 47 campuses having similar populations, socioeconomic makeups, and grade structures. This study utilized quantitative research measures to evaluate the level of special education populations on Reading First campuses using a response to intervention model. Quantitative measures were also used to evaluate those same campuses achievement rates of both special education and regular education students on the Texas Assessment of Knowledge and Skills reading tests. The study's outcome data showed little to no statistic significance for the three research questions. However, the inferential statistics showed a decrease in the special education population of the Reading First schools. Inferential statistics also indicated both the special education and the regular education students showed growth on the Texas Assessment of Knowledge and Skills reading tests. The use of a response to intervention …
Date: August 2013
Creator: Batts, Troy D.
System: The UNT Digital Library