Digital Commons Network^™

Bio-Socially Inspired Strategies In Support Of Dynamic Spectrum Access: An Evolutionary Game Theory Perspective, Mohammad Ali Marzoug Abu Shattal

Dissertations

Dynamic Spectrum Access (DSA) has been introduced to fulfill the expanded need for spectrum by different wireless networks and applications. Within the realm of spectrum access, the problem of "spectrum crunch" is present since some of the spectrum bands are overcrowded and others are underutilized. DSA aims to alleviate the problem of spectrum crunch. In DSA, Primary Users (PUs) allow Secondary Users (SUs) to access the spectrum as long as they do not interfere with PU transmissions beyond a pre-agreed acceptable level. In this work, a bio-socially inspired approach is proposed for SU interactions in support of better throughput for …

The Diversity, Costs, And Benefits Of Shelters Built By Lepidopteran Caterpillars In A Costa Rican Dry Forest, Christina Baer

Dissertations

Thousands of Lepidoptera species build shelters as caterpillars using plant material and their own silk. Although these caterpillars and their shelters are recognized as playing important ecological roles, the structural diversity of shelters and the costs and benefits of different shelters to their builders are still poorly understood. In this dissertation, I use natural history observations, observational and manipulative field projects, and molecular and phylogenetic tools to investigate these questions for a diverse and abundant shelter-building caterpillar community within the dry forest of Palo Verde National Park, Costa Rica. In Chapter 1, I develop a system for categorizing and describing …

Achilles Is A Circadian Clock-Controlled Gene That Regulates The Immune System And Its Rhythmicity In Drosophila, Jiajia Li

Dissertations

Circadian clock is a transcriptional/translational feedback loop that drives the rhythmic expression of downstream mRNAs. Termed “clock-controlled genes,” these molecular outputs of the circadian clock orchestrate cellular, metabolic, and behavioral rhythms. As part of our on-going work to characterize key upstream regulators of circadian mRNA expression, we have identified a novel clock-controlled gene in Drosophila melanogaster, Achilles (Achl), which is rhythmic at the mRNA level in the brain and represses expression of immune response genes, especially anti-microbial peptides in the immune system. Achl knock-down in the brain dramatically elevates expression of crucial immune response genes, including IM1 …

Interactions Between Amyloid-Beta And Microglial Cells, Lisa Gouwens

Dissertations

Alzheimer’s disease (AD), the most common cause of dementia, is a neurodegenerative condition characterized by loss of memory and intellectual abilities. Intracellular plaques of aggregated amyloid-beta (Ab) protein are a well-known pathology associated with AD. Although symptoms usually appear late in life, the accumulation of Ab begins decades earlier and causes activation of microglia, the brain’s immune cells. The ensuing inflammation contributes significantly to neurodegeneration. Determination of the particular form of Ab that causes the most damage in the brain is one of the major questions in the AD field. My research focused on the interactions of microglia with monomers, …

Processing Motion: Using Code To Teach Newtonian Physics, M. Ryan Massey

Dissertations

Prior to instruction, students often possess a common-sense view of motion, which is inconsistent with Newtonian physics. Effective physics lessons therefore involve conceptual change. To provide a theoretical explanation for concepts and how they change, the triangulation model brings together key attributes of prototypes, exemplars, theories, Bayesian learning, ontological categories, and the causal model theory. The triangulation model provides a theoretical rationale for why coding is a viable method for physics instruction. As an experiment, thirty-two adolescent students participated in summer coding academies to learn how to design Newtonian simulations. Conceptual and attitudinal data was collected using the Force Concept …

Gender Identity Work: Oppression And Agency As Described In Lifespan Narratives Of Transgender And Other Gender Non-Conforming Identified People In The U. S., Kathryn O'Brien

Dissertations

The purpose of this research was to critically examine the gender identity work of white transgender and other gender non-conforming identified (TgNCi) people through their stories and the meanings they attach to important artifacts across the lifespan. A single question directed the investigation: How do TgNCi individuals describe gender identity work through lifespan narratives? Thirteen volunteers participated in two interviews: the first, a narration of their life stories and in the second, descriptions of the significance of personal artifacts selected by the participants and photographed by the investigator. Participants’ ages ranged from 22 to 66, according to four pre-determined age …

Regulation Of Voltage-Gated K+ Currents In Motor Neurons: Activity-Dependence And Neuromodulation, Dalia Salloum

Dissertations

Neuronal output is shaped by extrinsic modulation as well as modulation of intrinsic properties of individual neurons, mediated by activity-dependent changes in the expression levels of voltage-gated ionic currents. Activity-dependent regulation of ionic currents is a mechanism by which electrical output of a neuron feeds back onto the expression of its own ion channels to alter cellular excitability in response to stimuli. Neurons alter their intrinsic properties to achieve long lasting changes involved in development, learning and memory formation and vital functions of organ systems such as locomotion and digestion. At the same time, plasticity of neuronal excitability driven by …

Machine Learning Based Digital Image Forensics And Steganalysis, Guanshuo Xu

Dissertations

The security and trustworthiness of digital images have become crucial issues due to the simplicity of malicious processing. Therefore, the research on image steganalysis (determining if a given image has secret information hidden inside) and image forensics (determining the origin and authenticity of a given image and revealing the processing history the image has gone through) has become crucial to the digital society.

In this dissertation, the steganalysis and forensics of digital images are treated as pattern classification problems so as to make advanced machine learning (ML) methods applicable. Three topics are covered: (1) architectural design of convolutional neural networks …

Biophysical Mechanisms Of Frequency-Dependence And Its Neuromodulation In Neurons In Oscillatory Networks, David Michael Fox

Dissertations

In response to oscillatory input, many isolated neurons exhibit a preferred frequency response in their voltage amplitude and phase shift. Membrane potential resonance (MPR), a maximum amplitude in a neuron’s input impedance at a non-zero frequency, captures the essential subthreshold properties of a neuron, which may provide a coordinating mechanism for organizing the activity of oscillatory neuronal networks around a given frequency. In the pyloric central pattern generator network of the crab Cancer borealis, for example, the pacemaker group pyloric dilator neurons show MPR at a frequency that is correlated with the network frequency. This dissertation uses the crab …

Modeling Subconcussive And Cumulative Subconcussive Impacts Using A Lateral Fluid Percusion Injury Device, Todd Long

Dissertations

Repetitive mTBI and concussion are a major risk factor for developing long-term cognitive and behavioral impairments. Curiously, cumulative head injuries sustained over an individuals’ career, involving contact activities (e.g. athletes and military personnel), are beginning to be implicated in long-term consequences, such as dementia. Recently, chronic traumatic encephalopathy (CTE) has gained momentum in the science and medical community as a neurodegenerative disease of repetitive head injuries. CTE was observed at autopsy of former athletes that did not closely correlate with a clinical history of concussion. Thus, suggesting cumulative subconcussive insults may induce long-term damage.

Investigating the etiology of subconcussive and …

“How Short Is A Piece Of String?”: An Investigation Into The Impact Of Text Length On Short-Text Classification Accuracy, Austin Mccartney

Dissertations

The recent increase in the widespread use of short messages, for example micro-blogs or SMS communications, has created an opportunity to harvest a vast amount of information through machine-based classification. However, traditional classification methods have failed to produce accuracies comparable to those obtained from similar classification of longer texts. Several approaches have been employed to extend traditional methods to overcome this problem, including the enhancement of the original texts through the construction of associations with external data enrichment sources, ranging from thesauri and semantic nets such as Wordnet, to pre-built online taxonomies such as Wikipedia. Other avenues of investigation have …

Perceived Influence Of The Ferguson Effect On Law Enforcement Officer Turnover Intentions, William P. Markopoulos Jr

Dissertations

Law enforcement officer turnover lacks the support of empirical research (Monk-Turner, O’Leary, & Sumter, 2010; Wareham, Smith, & Lambert, 2013), despite being costly in terms of both human and monetary capital (Peña, 2013; Reaves, 2012; Wilson & Sheer, 2013). What literature is available describes factors such as job dissatisfaction and monetary issues as reasons to leave an agency (Cyprian, 2009; Hubbard, 2008; McIntyre, 1990). A new phenomenon, known as the “Ferguson Effect” has been examined in terms of community involvement (Nix & Wolfe, 2016; Wolfe & Nix, 2016) and violent crime rates (Rosenfeld, 2015), but there is no research that …

The Role Of Personality Using The Millon College Counseling Inventory In Explaining A Variety Of Career Decision-Making Variables, Carly Chadick

Dissertations

In vocational research, the Five Factor Model (FFM) is one of the most popular theories of personality used when evaluating the role of personality in career development. However, thus far, few other personality theories have been used in vocational research, such as Millon’s theory. Therefore, the purpose of this study was to examine how Millon’s theory, operationalized using the Millon College Counseling Inventory (MCCI), may explain career development constructs, above the FFM traits, in a college student sample. Results indicated that the MCCI explained additional variance beyond FFM traits in several different career variables (i.e., profile elevation, negative career thinking, …

How Visual Communication Strategies, Brand Familiarity, And Personal Relevance Influence Instagram Users’ Responses To Brand Content, Lijie Zhou

Dissertations

This study comprehensively investigated the effects of visual themes, visual perspective, personal relevance, and brand familiarity on brand constructions (attitude-toward-brand, brand love, brand respect, and three dimensions of brand image) on Instagram. The study consists of two parts. In Study 1, the main and interaction effects of visual design elements on individuals’ visual attentions, brand recognition, and attitude toward brands were examined by using a 4 (visual theme: customer-centric, employee-centric, product-centric, and non-branded) × 2 (view perspective: first-person view vs. third-person view) between-subject eye-tracking test. In Study 2, a 4 (visual theme: customer-centric, employee-centric, non-brand, and product-centric) ×2 (brand familiarity: …

A Qualitative Study Investigating Facility Managers’ Perceptions Of The Classroom Learning Environment, Eric Shannon Parr

Dissertations

Facility managers have the challenge of adhering to community college policies and procedures while fulfilling requirements of administration, students, and teachers concerning specific needs of classroom aesthetics. The role of facility manager and how specific entities affect perceptions of the design and implementation of classroom aesthetics were presented in this study in an attempt to further clarify present classroom design practices and future aesthetic possibilities. The purpose of this study was to explore and compare a facility manager’s perceptions of classroom learning environments, and a student’s learning environment aesthetic needs. A qualitative research design was utilized within the theoretical framework …

Inhibitory Control And Its Relation To Personality/Temperament, Executive Function, And The Brain, Sarah Mailander Dyer

Dissertations

Inhibitory control, described as the ability to suppress one response in favor of a goal-directed response, is thought to play an important role in the development of emotional regulation as well as various forms of psychopathology, including ADHD. Up until very recently, inhibitory control has been researched within two completely separate fields of study: temperament and neuropsychology. In the temperament/personality literature, inhibitory control is a major component of the overarching temperament/personality factor of Effortful Control/Conscientiousness. In the field of neuropsychology, inhibitory control is considered one aspect of executive function. Further complicating the current understanding of inhibitory control is the complexity …

Effects Of Historical Story Telling On Student Understanding Of Nos And Mendelian Genetics, Cody Tyler Williams

Dissertations

Science education researchers have long advocated the central role of the nature of science (NOS) for our understanding of scientific literacy. NOS is often interpreted narrowly to refer to a host of epistemological claims associated with the process of science and the limitations of scientific knowledge. Despite its importance, practitioners and researchers alike acknowledge that students have difficulty learning NOS and that this in part reflects how difficult it is to teach. Many teachers are uncomfortable with taking time away from traditional science content instruction. One promising method for teaching NOS and science content involves an explicit and reflective approach …

From The Arab World To The American World: Transition And Adjustment Experiences Of Muslim Women, Nancy Hammoudah

Dissertations

This qualitative study explored the experiences of Muslim women from the Arab world who came to live and study in the U.S. This study gave voice to their daily lived experiences of transitioning to and adjusting to life and study in the American world. Nine bilingual women provided in depth responses to interviews and follow up phone calls. Women were raised in predominantly Muslim countries and attended institutions of higher education for the first time in the U.S. as international or domestic students, including refugees. Interviews were in English. Any spontaneous Arabic that was used by participants was immediately translated …

Sex Differences In Serotonergic And Dopaminergic Mediation Of Lsd Discrimination In Rats, Keli A. Herr

Dissertations

After decades of opposition, a resurgence of interest in the psychotherapeutic potential of LSD is gaining acceptance in the medical community. Future acceptance of LSD as a psychotherapeutic adjuvant may be predicated on knowledge about its neural mechanisms of action. Preclinical drug discrimination assay offers an invaluable model to determine the neural mechanisms underlying LSD’s interoceptive stimulus effects. Unfortunately, current preclinical literature on LSD discrimination is based on results obtained exclusively in male subjects. The present study represents the first known preclinical assessment of possible sex differences in the discriminative stimulus effects of LSD.

Adult female (n=8) and male (n=8) …

Power Analysis Of Longitudinal Data With Time-Dependent Covariates Using Generalized Method Of Moments, Niloofar Ramezani

Dissertations

Longitudinal data occur in different fields such as biomedical and health studies, education, engineering, and social studies. Planning advantageous research projects with both high power and minimum sample size is an important step in any study. The extensive use of longitudinal data in different fields and the importance of their power estimation, yet the limited resources about their respective power estimation tools, made it worthwhile to study their power estimation techniques. The presence of time-dependent covariates triggers the need to use more efficient models such as generalized method of moments than the existing models which are based on generalized estimating …

Evolution Of Caffeine Biosynthetic Enzymes And Pathways In Flowering Plants, Ruiqi Huang

Dissertations

Convergent evolution generally refers to the independent evolution of similar biological function more than once in unrelated species. Caffeine is thought to have evolved by convergence, and is naturally produced through secondary metabolism in plants to defend against pathogen attack and insect feeding or to attract pollinators. The same caffeine biosynthetic pathway has been elucidated in Camellia (tea) and Coffea (coffee), in which xanthosine is sequentially methylated to caffeine via 7-methylxanthine and theobromine. However, although the same catalysis pathway is used, different (paralogous) enzymes in the SAMT/BAMT/theobromine synthase (SABATH) multigene family are used in the two species. In my dissertation, …

Cellulose Reinforced Thermoplastic Composites By In-Situ Ring-Opening Polymerization, Shahab Kashani Rahimi

Dissertations

Over the past two decades, the increasing concern about the negative environmental impacts of synthetic materials has led to rising interests in utilizing renewable natural resources to develop polymer materials with comparable properties and performance to their synthetic counterparts. One of the major fields of interest is polymer composites where the replacement of synthetic fibers with bio renewable natural fibers is of great potential. However, the processing difficulties, in terms of fiber dispersion and thermal stability have limited the application of cellulosic fibers to polymers with low processing temperatures which are mostly hydrophobic polymers. As a result, the true reinforcing …

The Effects Of Training Multiple Mands Within Functional Communication Training On The Resurgence Of Problem Behaviors, Emily Jane Ness

Dissertations

Resurgence is the reoccurrence of a previously reinforced behavior when, under similar circumstances, a more recently reinforced behavior is placed on extinction (Epstein, 1985). The resurgence of problem behavior within the context of functional communication training (FCT) may occur when reinforcement is inadvertently thinned or placed on extinction due to low implementation integrity throughout the course of the intervention (Lieving et al., 2004). Techniques evaluated to mitigate resurgence of problem behavior have included long-term exposure to extinction (Wacker et al., 2011), signaled schedule thinning (Fuhrman, Fisher, and Greer, 2016), and a combination of both techniques (Wacker et al., 2013). These …

Educators’ Perceptions Of The Substitution, Augmentation, Modification, Redefinition Model For Technology Integration, Mark Angelo Savignano

Dissertations

The Substitution, Augmentation, Modification, Redefinition (SAMR) model has been introduced (Puentedura, 2006) claims that use of technology could predict student outcomes. School districts and educational institutions have been adopting this model in hopes to enhance the educational experience and outcomes for their students (SAMR Model, n.d.). This study explored six teachers’ and three administrators’ perception of the SAMR model in integrating technology into the classroom environment. This qualitative research, used surveys and interviews for indicative analysis using the constructivist approach. Data analysis found that educators using the SAMR model were and had a common level used for technology integration as …

Evaluating The Effects Of "On-Task In A Box" As A Class-Wide Intervention For Increasing On-Task Behavior And Academic Performance, Allison Ashley Battaglia

Dissertations

The present study was designed to replicate and extend the literature on the intervention package, On-Task in a Box, as a class-wide intervention to increase on-task behavior and decrease disruptive behavior. A second purpose of the study was to evaluate the effects of the intervention on students’ academic performance. The On-Task in a Box intervention utilized video modeling to train students on how to engage in on-task behavior, as well as how to self-monitor their behavior. Additionally, the intervention included students self-monitoring their on-task behavior using self-recording forms. Depending on select students’ percentage of on-task behavior on the self-recording forms, …

The Good Behavior Game: Effects On And Maintenance Of Behavior In Middle-School Classrooms Using Class Dojo, Komila Dadakhodjaeva

Dissertations

Classroom management is one of the key components for successful instruction and affects both instructors and learners. Although most frequent discipline strategies in schools involve punitive actions, research suggests that using positive statements to teach and reinforce desirable behaviors is more appropriate and effective. A form of a group-oriented contingency that focuses on desirable behaviors is a positive variation of the Good Behavior Game (GBG). The GBG has been used widely in its original form, focusing on undesirable behaviors, and more research is needed on its positive version. Another strategy that can be used within classrooms is Class Dojo, a …

Evaluating Relevance And Reliability Of Twitter Data For Risk Communication, Xiaohui Liu

Dissertations

While Twitter has been touted to provide up-to-date information about hazard events, the relevance and reliability of tweets is yet to be tested. This research examined the relevance and reliability of risk information extracted from Twitter during the 2013 Colorado floods using five different approaches. The first approach examined the relationship between tweet volume and precipitation amount. The second approach explored the relationship between geo-tagged tweets and degree of damage. In the third approach, the spatiotemporal distribution of tweets was compared with flood extent. In the fourth approach, risk information from tweets were compared with survey responses obtained in a …

The Body Mends Itself, Hannah Elizabeth Dow

Dissertations

The following poems were completed by the author between September 2014 and April 2017.

An Ecological Examination Of Johnson Bayou (Pass Christian, Ms) With A Reproductive Histological Analysis Of Rangia Cuneata, And A Comparative Morphological Study Of The Foot And Shell Of Rangia Cuneata And Polymesoda Caroliniana, Brandon Drescher

Dissertations

Johnson Bayou is an estuarine system located in Pass Christian, MS. Research involved a biotic and abiotic examination of Johnson Bayou, resulting in the identification of numerous species of plants and animals, including Rangia cuneata (Mactridae) and Polymesoda caroliniana (Cyrenidae), sympatric species of infaunal bivalves. Environmental factors (e.g., water temperature, salinity) were measured over three years to describe the system from an abiotic standpoint, and used in a qualitative and quantitative reproductive histological study on R. cuneata. Results revealed differences in timing of gamete production and spawning between three subpopulations of this species. Sediment samples taken from the study …

An Evaluation Of Behavioral Skills Training On The Implementation Of Peer-Mediated Discrete Trial Training, Christopher M. Furlow

Dissertations

The purpose of this study was to evaluate the effects of behavioral skills training on the implementation of an evidence-based teaching method by student interventionists for children with autism spectrum disorder (ASD). Three elementary school students were trained to use an applied behavior analysis (ABA) based instructional method, known as discrete trial training (DTT), to teach academic skills to children with ASD. A multiple baseline across individuals was used to demonstrate the effectiveness of the behavioral skills training and peer-mediated DTT procedures. Generalization of the interventionist’s ability to teach new, previously untrained target behaviors was assessed by conducting generalization probes …