Digital Commons Network^™

Characterization Of Bacterial Peptidyl-Trna Hydrolase 1 From Different Phylogenetic Clades, Daniel Joseph Scott Strange

Dissertations

Antibiotic resistant bacterial infections have become increasingly difficult to treat resulting in approximately 23,000 deaths per year in the U.S. alone. Some bacterial infections, like P. aeruginosa and M. tuberculosis, have become pan- and multi-drug resistance further limiting treatment options. This has placed an increased demand on the medical community to find novel antibiotics and novel antibiotic drug targets that can be used for narrow spectrum inhibition of bacteria. One such target is bacterial peptidyl- tRNA hydrolase 1 (Pth1). Pth1 recycles tRNA by hydrolyzing the bond between peptidyl-tRNA and the growing polypeptide chain during abortive translation, thus, allowing free tRNA …

Synthesizing Realistic Social Networks Using Personality Compatibility, Daniel Anthony O'Neil

Dissertations

Social structures and interpersonal relationships may be represented in abstract mathematical objects known as social networks. A social network consists of nodes corresponding to people and links between pairs of nodes corresponding to relationships between those people. Social networks can be constructed by examining groups of people and identifying the relationships of interest between them. There are circumstances where such empirical social networks are unavailable, or their use would be undesirable. Consequently, methods to generate synthetic social networks that are not identical to real-world networks but have desired structural similarities to them are valuable. A process for generating synthetic social …

Protocol Misbehavior Mitigation Framework For Broadcast Communications In Vehicular Ad Hoc Networks, Kumar Sharshembiev

Dissertations

Vehicular Ad Hoc Networks (VANET) have a great potential to become the next technological paradigm shift to enable Intelligent Transportation Systems (ITS). Over the years, significant research progress has been made in VANETs to develop standards, protocols and applications to improve driver/passenger safety, traffic efficiency, and general cooperative awareness. Broadcast communications are the main critical information dissemination method in VANETs. Such wireless broadcasts empower highly dynamic network nodes in VANETs to quickly share pertinent information (emergency accident alert, road conditions, etc.) with each other. The highly dynamic nature of moving nodes and geographical constraints make the VANET topology a complex …

Analysis And Mitigation Of Laser Frequency Drift And Its Application In Fiber-Optic Sensing, Dipen Barot

Dissertations

Ultralow-noise and ultra-stable sources of reference signals in the optical domain have become indispensable for applications such as precision measurements, optical sensing, optical frequency metrology, coherent optical communications, and microwave photonics. Such sources possess not only very narrow linewidth but also absolute frequency stability. Attaining high frequency stability in the optical domain requires innovative approaches to analyze and mitigate frequency noises and drifts. In this dissertation, a novel scheme of laser frequency analysis with improved specificity is proposed and demonstrated. The proposed method is based on power spectral density (PSD) measurement in the radio-frequency (RF) range aided by electronic frequency …

Is There A Correlation Between Wikidata Revisions And Trending Hashtags On Twitter?, Paula Dooley

Dissertations

Twitter is a microblogging application used by its members to interact and stay socially connected by sharing instant messages called tweets that are up to 280 characters long. Within these tweets, users can add hashtags to relate the message to a topic that is shared among users. Wikidata is a central knowledge base of information relying on its members and machines bots to keeping its content up to date. The data is stored in a highly structured format with the added SPARQL protocol and RDF Query Language (SPARQL) endpoint to allow users to query its knowledge base.

Determination Of The Roles Of Non-Conserved Residues Surrounding The Functional Ggq Motif Of Rf2 In Translation Arrest, Jerusha Salome Emmanuel

Dissertations

The metabolism of bacteria is finely tuned through differential regulation of gene expression, which allows bacteria to adapt to changes in the external environment. Oftentimes, expression of genes is regulated during protein synthesis. Changes in concentration and chemical composition of factors involved in protein synthesis contribute to the regulation of the expression of genes. Such differences are often exploited by researchers to control cell growth of microorganism of health and industrially relevant. Regulation of protein synthesis often produces the machinery called ribosome to stall (also known as ribosome arrest), where interactions between ribosomal nucleotides, translation factors, the nascent peptide and …

Development Of Absorption-Coefficient-Based Narrow-Band Model And Its Application To The Calculation Of Radiative Heat Transfer In One And Two-Dimensional Enclosures, Annette Fisher

Dissertations

A narrow band model (NBM) with the absorption coefficient as the fundamental radiative property is investigated so that numerical solution methods compatible with the differential form of the radiative transfer equation (RTE) may be employed. The advantage of a NBM based on the absorption coefficient rather than the transmissivity is that the expression for the mean absorption coefficient is independent of the functional form of the probability density function for spectral line intensities, P(S). Accordingly, it is seen that the narrow-band mean absorption coefficient κ_η=^S/_d, where S and d are the mean line …

Characterization Of Putative Peptidyl-Trna Hydrolase Domain Containing 1, Geordan L. Burks

Dissertations

Putative peptidyl-tRNA hydrolase domain containing 1 (PTRHD1) is a eukaryotic protein predicted to be a Pth2-like peptidyl-tRNA hydrolase. Peptidyl-tRNA hydrolases (Pth) perform the essential function of recycling tRNA from peptidyl-tRNA in the event of translational failure. This function is ubiquitous in all domains of life. Homologues of bacterial (Pth1) and archaeal (Pth2) Pths are present in eukaryotes; however, simultaneous knockout of Pth1 and Pth2 has no effect on cell viability, suggesting the presence of additional proteins in eukaryotes that contain Pth activity. PTRHD1 was proposed as one such eukaryotic Pth and was tested for Pth hydrolase activity. While PTRHD1 did …

Study Of Plume Dynamics From Laser-Ablated Elemental Materials For Propulsion Application, M. Shane Thompson

Dissertations

The efficacy of utilizing material ablation from picosecond laser pulses onto elemental metal targets for propulsion applications is studied by a variety of measurement methods to characterize laser ablation plume dynamics. A 100 ps, 532 nm laser is used for ablating elemental metals, and the resulting ablation plume dynamics are measured by time-of-flight (TOF) energy analyzer probes, a piezoelectric force sensor, and an intensified imager. Results indicate that plume dynamics exhibit a material dependence and behave in a manner indicative of laser-induced plasma formation and expansion, and indicate that ablation-based laser propulsion is characterized by high specific impulses (on the …

Detection Of Offensive Youtube Comments, A Performance Comparison Of Deep Learning Approaches, Priyam Bansal

Dissertations

Social media data is open, free and available in massive quantities. However, there is a significant limitation in making sense of this data because of its high volume, variety, uncertain veracity, velocity, value and variability. This work provides a comprehensive framework of text processing and analysis performed on YouTube comments having offensive and non-offensive contents.

YouTube is a platform where every age group of people logs in and finds the type of content that most appeals to them. Apart from this, a massive increase in the use of offensive language has been apparent. As there are massive volume of new …

A Look Inside The Black Box: Understanding Communicative Exchanges In Online Learning Environments, Sara Douglas

Dissertations

Participation in academic discussions and peer collaboration activities is instrumental to student engagement, motivation, and mastery of course content. These activities also improve 21st century skills, such as listening, managing diverse viewpoints, and communicating effectively. Although online learning options in the United States have dramatically increased in the past decade, there is limited evidence that online high school courses offer sufficient opportunities for students to communicate and collaborate with teachers and peers. The purpose of this mixed-methods study seeks to find out if, how, and why students interact with others in online courses. Findings from observations of five high school …

The Contribution Of P. G. Wodehouse To The Field Of Gastronomy Through His Character, The French Chef, Anatole, Elizabeth Wilson

Dissertations

In her paper ‘A Cultural Field in the Making: Gastronomy in 19th-Century France’, Priscilla Parkhurst Ferguson argues that the field of gastronomy came into existence in the middle of the nineteenth century in France. This field of gastronomy was constructed from two elements, the significance that gastronomy, defined at the time as a structured set of culinary practices, had attained in France by the nineteenth century, but also, the contribution of writers of culinary discourse who wrote about this gastronomy. These writers came from different disciplines and included the realist fiction writer Honoré de Balzac (1799-1850), whose work Ferguson describes …

Variations In Individualistic And Collectivistic Cultural Orientation And The Protective Factors That Contribute To Resilience: Comparisons From Jamaica, Rwanda, And The United States, Stacey Nicely

Dissertations

Problem

Despite the advancement in resilience research, and although mental health professionals are encouraged to become culturally competent, it is still unclear how I/C cultural orientation influence various protective factors that contribute to resilience. Individualists emphasize independence and autonomy while collectivists emphasize interdependence and in-group consensus (Hofstede, 1991; Markus & Kitayama, 1991). Therefore, it is expected that the protective factors that promote resilience will also operate differently for individualists as compared to collectivists (Triandis, 1995). Yet, mental health practitioners have very little information available to them to guide their intervention efforts with individualists and collectivists. When practitioners work with individuals …

Examining Perceptions Of Service Quality Of Student Services And Satisfaction Among International Students At Universities In Indiana And Michigan, Mordekai Ochieng Ongo

Dissertations

Problem

Universities in the United States face financial constraints, intense competition for students, declining student enrollment, and constant student attrition. However, an increasing number of international students seek higher education abroad, especially in the U.S. Providing quality services to these international students might help institutions attract and retain more of them. Unfortunately, little empirical research has been done on international students’ perceptions of service quality, especially of non-academic services. This study fills that gap by using a modified SERVPERF questionnaire to investigate international students perceived service quality and satisfaction at eight universities in Indiana and Michigan.

Method

The purpose of …

The Influence Of Pornography Consumption, Religiosity, And Family Sexual Communication On Emerging Adults' Engagement In Hookup Culture In The United States, Angie Powels Horner

Dissertations

Purpose

The primary purpose of the current research was to understand the influence of considerable social-cultural factors, including pornography consumption, religiosity, and family sexual communication, on the sexual values and behaviors of the emerging adult population. Particularly, how pornography consumption, religiosity, and family sexual communication influence emerging adult engagement in hookup culture was examined.

Method

Participants completed several surveys, which measured participants’ pornography consumption, personal religiosity, family sexual communication, and engagement in hookup culture. A path analysis model was used to analyze the relationship between the proposed variables.

Results

The path analysis model indicated that the initial model was a …

Adventist Healthcare: A Qualitative Study Of 19th Century Founding Governing Principles In 21st Century Adventist Hospitals, Cesiah Yareth Pimentel Melendez

Dissertations

Problem and Purpose

Founding values and principles can help organizations stay focused on fulfilling their mission. This is especially true in faith-based organizations that seek to continue their founding principles as a governing commitment to their core identity. This study identified Adventist healthcare founding principles in Ellen G. White's early health visions and explored how Adventist healthcare leaders perceived these principles as governing principles applied to current Adventist healthcare practices.

Conceptual Framework and Research Design

Two metaphors and three areas of literature review guided my approach of this qualitative study of Adventist healthcare founding principles. My first metaphor of DNA …

The Relationship Between Combat Experience, Veteran Pathology And The Pathology Of Their Intimate Partners: What Factors Predict The Pathology Of Veterans And Their Intimate Partners, Edwin A. Brennan

Dissertations

Problem Statement

Military members and their family members who are part of the Global War on Terrorism have experienced deployments and war for over sixteen years and with the resulting toll on both the veteran and their intimate partner. As a result, higher levels of pathology, such as PTSD, Anxiety, and Depression have been experienced by this population. While research has studied the effect of combat on military members, very little research has addressed the effects on family members. Further, no research that has been found by this researcher, has addressed the concept of resonating of pathology between the combat …

Women's Decision-Making For Subsequent Pregnancy After A Cesarean Delivery, Melinda Dixon

Dissertations

The purpose of this study is to generate a theory of the decision making process for women as they choose a birth option after a previous Cesarean delivery. The research method of choice when little is known about the phenomena is qualitative research. A qualitative approach was used to generate a substantive theory of decision making for women deciding subsequent pregnancy birth mode after a previous Cesarean delivery. The classical grounded theory methodology including sampling plan, recruitment, data collection and analysis outlined in Glaser and Strauss (1967) guided this study. Twelve study participants with a history of one previous Cesarean …

Latina College Student Leadership Development At A Historically White College/University, Kristina Garcia

Dissertations

This dissertation study contributes to the dearth of research examining the leadership development of Latina college students. Using critical race feminism (CRF) as a guiding framework, this study centers the experiences of Latina college students, exploring how dominant cultural values, Latinx cultural values, and the context of the collegiate environment influence how this population experiences leadership development. Utilizing a qualitative research design, participants shared stories and insights related to how they conceptualized and experienced leadership development in the context of a historically White college/university. The data indicates that Latina college students experience leadership as a constant negotiation of dominant cultural …

Membrane Microdomains As Platforms For Extra-Cellular Fusions, Michael Hantak

Dissertations

Life requires biological membranes. Membrane-enclosed compartments separate and unite through dynamic fission and fusion reactions. These are catalyzed processes that are central in organismal biogenesis. This dissertation focuses on extracellular membrane fusions, which are central to several processes. (1) Enveloped viruses enter cells through membrane fusions. (2) Extracellular vesicles (EVs) also deliver molecules into cells through membrane fusions. (3) Entire cells also fuse together, generating fertilized zygotes, skeletal muscles, and giant cell macrophages.Mechanisms of extracellular membrane fusion are poorly understood. This dissertation aimed to further define these mechanisms. We focused on regulatory cofactors, including tetraspanins, transmembrane proteins that cluster into …

From Design To Implementation: A Case Study Of A New Two-Year College, Brian M. Knetl

Dissertations

The purpose of this dissertation was to understand how a new two-year college was designed and implemented within the context of and as a response to the completion agenda by focusing on the decisions and actions of the Administrative Leadership Team (ALT). The research was framed around the completion agenda themes of access, affordability, and student supports. An instrumental case study methodology was used to gain a deep understanding of the new college within the context of the completion agenda. Observations of ALT meetings, interviews with members of the ALT, and documents were collected and analyzed. The findings revealed that …

The Social And Contextual Mechanisms Of Children's Learning In Museums, Lindsay R. Maldonado

Dissertations

This study explored the associations between immersive exhibit design, mother-child engagement, conversational interactions, and children's learning. Participants were 41 mothers and their 6-8-year-old children (Mage=7.15, SD=.79). A within-subjects, mixed methods approach was utilized, including naturalistic observations, interview data, and surveys. Mother-child dyads were video and audio-recorded as they visited four different exhibits: two low immersion exhibits and two high immersion exhibits. Interview data was collected from children immediately following the visit to assess learning. Survey data was collected from mothers to assess education, environmental predispositions, and science-related career. In high immersion exhibits, mothers and children spent more time and asked …

Exhibiting Sovereignty: Tribal Museums In The Great Lakes Region, 1969-2010, Meagan Mcchesney

Dissertations

This dissertation argues that the foundation and development of tribal museums in the Great Lakes region is a form of activism -- a deliberate action performed for the purpose of inciting positive political, social, cultural, and/or economic change -- and that the functions of tribal museums enable Native activism to continue and evolve to reflect and address new historical understandings and contemporary circumstances. I argue that in the Great Lakes region, Native activism continued beyond the highly publicized movement of the 1960s and 70s, and manifested in ways suited to address regionally and tribally-based needs. Control over interpretations of the …

Characterization Of The Effects Of Sex And Estrogen Receptor Signaling On Antigen-Specific T Cells For Immunotherapy, Flor Cecilia Navarro Negredo

Dissertations

Adoptive cell transfer (ACT) immunotherapy using antigen (Ag)-specific T cells is partially effective treating several malignancies but numerous challenges remain in order to improve its therapeutic potential. The roles of host factors, such as sex hormone receptor signaling, that can affect the T cell anti-tumor function remain understudied. The work performed in this dissertation characterized the role of estrogen signaling on T cell function in vitro, and during ACT immunotherapy against hepatocellular carcinoma (HCC) in vivo. Estrogen signaling through ERa enhanced the expression and secretion of Type I effector cytokines including IFNg, TNFa, and Granzyme B in male and female …

Analyzing Twitter Feeds To Facilitate Crises Informatics And Disaster Response During Mass Emergencies, Arshdeep Kaur

Dissertations

It is a common practice these days for general public to use various micro-blogging platforms, predominantly Twitter, to share ideas, opinions and information about things and life. Twitter is also being increasingly used as a popular source of information sharing during natural disasters and mass emergencies to update and communicate the extent of the geographic phenomena, report the affected population and casualties, request or provide volunteering services and to share the status of disaster recovery process initiated by humanitarian-aid and disaster-management organizations. Recent research in this area has affirmed the potential use of such social media data for various disaster …

An Evaluation Of The Information Security Awareness Of University Students, Alan Pike

Dissertations

Between January 2017 and March 2018, it is estimated that more than 1.9 billion personal and sensitive data records were compromised online. The average cost of a data breach in 2018 was reported to be in the region of US$3.62 million. These figures alone highlight the need for computer users to have a high level of information security awareness (ISA). This research was conducted to establish the ISA of students in a university. There were three aspects to this piece of research. The first was to review and analyse the security habits of students in terms of their own personal …

An Investigation Into The Predictive Capability Of Customer Spending In Modelling Mortgage Default, Donal Finn [Thesis]

Dissertations

The mortgage arrears crisis in Ireland was and is among the most severe experienced on record and although there has been a decreasing trend in the number of mortgages in default in the past four years, it still continues to cause distress to borrowers and vulnerabilities to lenders. There are indications that one of the main factors associated with mortgage default is loan affordability, of which the level of disposable income is a driver. Additionally, guidelines set out by the European Central Bank instructed financial institutions to adopt measures to further reduce and prevent loans defaulting, including the implementation and …

Analysis Of Acoustic Emission Signals In Aluminum And Composite Structures, Duy Quang Tran

Dissertations

Acoustic emission signal in aluminum plates and composite specimens are examined in this dissertation. The first part of the dissertation examines the symmetric lamb wave modes generated by the spontaneous appearance of a central microcrack in an aluminum plate. The detected acoustic emission amplitude of these waves with radial and angular position of the sensing location was analyzed using finite element analysis. An important aspect of this study is the detailed characterization of the shear horizontal mode of the Lamb wave that is generated by simulated crack growth. This analysis indicates that the amplitude of the shear horizontal mode remains …

Domain Decomposition Methods For The Solution Of Multiple Scattering Problems, Michael Pedneault

Dissertations

This presents a Schur complement Domain Decomposition (DD) algorithm for the solution of frequency domain multiple scattering problems. Just as in the classical DD methods,(1) the ensemble of scatterers is enclosed in a domain bounded by an artificial boundary, (2) this domain is subdivided into a collection of nonoverlapping subdomains so that the boundaries of the subdomains do not intersect any of the scatterers, and (3) the solutions of the subproblems are connected via Robin boundary conditions matching on the common interfaces between subdomains. Subdomain Robin-to-Robin maps are used to recast the DD problem as a sparse linear system whose …

The Cooperative Effects Of Channel Length-Bias, Width Asymmetry, Gradient Steepness, And Contact-Guidance On Fibroblasts’ Directional Decision Making, Quang Long Pham

Dissertations

Cell migration in complex micro-environments, that are similar to tissue pores, is important for predicting locations of tissue nucleation and optimizing scaffold architectures. Firstly, how fibroblast cells - relevant to tissue engineering, affect each other’s directional decisions when encountered with a bifurcation of different channel lengths was investigated. It was found that cell sequence and cell mitosis influence the directional choices that the cells made while chemotaxing. Specifically, the fibroblasts chose to alternate between two possible paths - one longer and the other shorter - at a bifurcation. This finding was counter-intuitive given that the shorter path had a steeper …