Digital Commons Network^™

Carbon And Nitrogen Dynamics In Fluvial Systems Across Biomes, Bianca Rodriguez-Cardona

Doctoral Dissertations

Carbon (C) and nitrogen (N) cycles are tightly coupled in ecosystems as many N transformations rely on carbon as the energy source. In aquatic ecosystems this coupling between C and N has been studied via assessment of dissolve organic carbon (DOC) and inorganic-N concentration or whole stream manipulations of C and/or N to determine the influence of C on N processing. However, the majority of these studies have been performed in temperate systems and whether these relationships hold across other biomes, like artic and tropics, is unclear. In addition, how the more N-rich organic matter or dissolved organic nitrogen (DON) …

Synthesis And Characterization Of Biomimetic Model Systems For The Study Of Diiron Hydrogenase And Porphyrin Enzymes, Brian Francis Patenaude

Doctoral Dissertations

The branch of biomimetic chemistry aims to imitate natural reactions and enzymatic processes in order to advance many other areas of chemistry, including inorganic and organic catalysis as well as materials science. To study the mechanisms of enzyme activity and the effect of secondary coordination sphere interactions, the synthesis and characterization of two artificial metallo-enzymes were pursued.

In order to further understand the mechanism of [FeFe]-hydrogenase and the effect of secondary coordination sphere interactions within the protein binding pocket, the synthesis of an optimized biotin-avidin [FeFe] artificial enzyme was pursued. This dissertation describes the synthesis and characterization of the small …

Am I A Math Or Science Person? How High School Students’ Attitudes Towards Mathematics And Science Influence Their Decision To Major In Stem, Dalton Dayne Marsh

Doctoral Dissertations

Motivated by an innovation-driven economy, critical emphasis has been placed on the science, technology, engineering, and mathematics (STEM) workforce in the United States. Education has been charged to prepare a diverse population of young people qualified to take up these jobs and lead the nation into a rapidly evolving technological future. How to best approach this goal is still being negotiated. While past research and efforts focused largely on improving students’ achievement in mathematics and science, more recent research points to the need to also consider students’ attitudes towards STEM subjects. However, what types of attitudes (e.g., self-efficacy, identity, interest, …

Understanding Earthquake Rupture Processes: Insights From Mid-Ocean Ridge Transform Faults And Submarine Volcanoes, Pamela Moyer

Doctoral Dissertations

Key goals of earthquake science are to understand properties that control where earthquakes start, stop and spread, as well as their ground shaking potential. Stress drop, proportional to slip over the rupture length, provides insight into how variations in material properties of the fault affect the slip behavior of earthquakes. Using data from two ocean bottom seismic experiments, this dissertation explores variations in stress drop in small to moderate magnitude earthquakes in two tectonic environments where heterogeneous fault zones are inferred. On Gofar Transform Fault on the East Pacific Rise, the largest earthquakes (6.0 ≤ MW ≤ 6.2) repeatedly rupture …

Life After The El Label: Conversations About Identity, Language, And Race, Veronica Arizaga Aguayo

Doctoral Dissertations

Currently, the English Learner (EL) label is found in every facet of education concerning learners with home languages other than English. While the EL label is designated to objectively identify students who are indeed learning English, it also brings with it an unintentional, outward forced identity that institutes an unwillingness among peers and teachers to socially and academically engage with EL-labeled students. Not only has the label warranted inequitable academic opportunities, wide graduation gaps, and a consistently wide achievement gap, it has also perpetuated a deficit model and negative perceptions of the learners, especially with the racialized rhetoric that has …

Enacting And Refining Critical Teaching: A Multi-Case Study On Criminology/Criminal Justice Professors, Joshua Abreu

Doctoral Dissertations

This multi-case study centers on how Criminology/Criminal Justice (CCJ) professors enact and refine a teaching approach that helps students understand how practices from their field of study can reinforce systemic discrimination and its harmful consequences. These are practices that have disproportionately threatened the physical, emotional, and/or economic conditions of communities with limited socio-political power. This research is important because college instructors play an influential role in preparing and enhancing the country’s workforce. Thus, if college instructors do not prepare students as critically-minded professionals, then students may reproduce practices that can lead to detrimental social, political, and economic outcomes for the …

Development And Mechanistic Investigation Of Mixed Metal Oxides (Mmos) And Nanocomposites As Multi-Functional Catalysts, Laura Achola

Doctoral Dissertations

There are 4 chapters in this thesis. Chapter 1 presents photo-assisted PMS activation using cobalt doped mesoporous iron oxide with exceptional activity and stability up to 6 cycles and very low cobalt leaching. The effects of cobalt doping are shown using different characterization techniques. The high surface area and monomodal pore sizes are maintained with minimal cobalt incorporation. This study correlates the activity to increased labile oxygen induced by cobalt doping. Chapter 2 details the synthesis of mesoporous first–row transition metal ferrites. M²⁺ (Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn …

Development And Application Of Incompatible Graded Finite Elements For Analysis Of Nonhomogeneous Materials, Asmita Rokaya

Doctoral Dissertations

Functionally graded materials (FGMs) are non-homogenous and tailored to have a spatial variation of properties. The gradual modification of material properties is quite effective in reducing stresses. Finite element analysis of nonhomogeneous materials can be performed using an assemblage of either graded or homogeneous elements. A graded finite element samples the material property at more than one integration points, while a homogeneous element has constant property at all integration points based on the property of the element at the centroid. In this dissertation, a six-node incompatible graded finite element is developed.

This research aims to show significance of six-node incompatible …

Secondary School Athletic Trainers: Examining Leadership Development, Kelly Coleman

Doctoral Dissertations

Background: In order to fully comprehend leadership, it is not only important to consider characteristics that define effective leadership, but also to determine behaviors that are deemed important in athletic training leadership practice. Previously, leadership behaviors have been examined in collegiate educators and head athletic trainers (ATs), but not in the secondary school athletic trainer population.

Purpose: To explore the frequency with which ATs in the secondary school setting practice leadership behaviors within and outside their professional roles across various demographic characteristics, and to investigate the leadership styles of secondary school ATs and determine what demographic characteristics influence the use …

Racial/Ethnic Differences In Attitudinal Treatment Engagement Among Adolescents And Young Adults, Linda A. Oshin

Doctoral Dissertations

Low engagement in mental health treatment is a problem across racial/ethnic, socioeconomic, and gender lines. Disparities in treatment engagement are particularly evident among certain racial/ethnic groups and may result in part from different beliefs about mental health and psychotherapy (Yasui et al., 2017). Despite evidence of engagement disparities, there is limited research on the attitudes that youth of color have toward mental health treatment. The current studies investigate racial/ethnic differences in beliefs about treatment among adolescents and young adults. Study 1 was a retrospective cohort analysis examining self-reported readiness for psychotherapy among adolescents admitted to a psychiatric inpatient unit. Results …

Parenting After The Death Of A Co-Parent: A Qualitative Study Of The Lived Experiences Of Surviving Parents, Erin Donohue

Doctoral Dissertations

Findings from this study suggest that surviving parents’ parenting experiences following a co-parent’s death are difficult and multifaceted in comparison to co-parenting before the death. A parent’s death is an unexpected event that incurs family stress and grief for remaining family members, whom often include the surviving parent and dependent children (i.e., children under the age of 18). Following loss, it is typical for family members to experience role confusion and reorganization, as the surviving parent is expected to fulfill certain norms (i.e., assuming full guardianship and parenting roles) with their children. According to Belsky’s Process Model of Parenting, bereavement-related …

Identifying Developmentally Effective Experiences And Self-Authorship Among Professional Masters Athletic Training Students, Sarah Myers

Doctoral Dissertations

Context. An understanding of valuable as well as ineffective learning experiences from the perspective of the professional masters (PM) athletic training student and how their level of development connects to these perceptions is needed to continue to encourage growth in the adult learner, a new type of scholar in many athletic training education programs (ATP).

Objective. Develop an understanding about the learning experiences that resonate positively and negatively with second year PM athletic training students, both in the classroom as well as in their clinical education. Create a theory about developmental level and perceptions of learning.

Design. Exploratory, qualitative using …

The Relationship Between Campus Climate, Sexual Assault Victimization, And Reporting Sexual Assault To Campus Officials For Lgbtq College Students, Sarah Nightingale

Doctoral Dissertations

Sexual assault is a persistent problem on college colleges and has been found to impact the health, well-being, and academic success of survivors. Lesbian, gay, bisexual, transgender, and queer/questioning (LGBTQ) college students experience sexual assault victimization at disproportionately higher rates compared to their cisgender, heterosexual peers. Federal Title IX legislation in the United States (U.S) requires higher education institutions to have systems in place to respond to reports of sexual assault and support the students affected. However, few students report sexual assault to college officials. This dissertation seeks to contribute to the understanding of campus sexual assault by exploring relationships …

Recognizing Patient Deterioration: A Quantitative Study On Patient Outcomes In The Adult Acute Care Setting, Zachary Krom

Doctoral Dissertations

The identification of patient deterioration is significant because, in its absence, adverse events may go unnoticed and quickly escalate in severity. Only 17.4% of patients experiencing in-hospital cardiac arrest are seen by medical response teams, such as a rapid response or code blue team (Chan, et al., 2016). The purpose of this secondary data analysis was to determine if the frequency and rationale for RRT and code blue calls are related to nursing staff exposure to a deterioration recognition education program. Eleven medical surgical and five progressive care units at an urban academic medical center were included in the study. …

Knowledge, Attitudes, And Self-Efficacy Changes In Advance Care Planning With A High-Fidelity Simulation: Conversations Had At Trying Times (Chatt), Amisha Parekh De Campos

Doctoral Dissertations

Background: Advance care planning (ACP) conversations aim to ensure the articulation and documentation of patients’ health care goals. These conversations should occur early and longitudinally. However, they are often not done or not done iteratively. Clinicians lack training and knowledge in ACP to have effective conversations. Therefore, a simulation was developed and tested among registered nurses (RN).

Aim: This study aimed to examine the feasibility of an ACP simulation called Conversations Had at Trying Times (CHATT) among RNs, and to explore changes in knowledge, attitudes, and self-efficacy.

Theoretical Framework: A framework was developed with the National League of Nursing Jeffries …

The Equitable Leadership Practices Of Teacher Leaders In Secondary Science Instruction, Latanya T. Brandon

Doctoral Dissertations

The purpose of this case study is to investigate science teacher leadership for educational equity at the secondary school level during a period of reform. The current reform in science education acknowledges inequity and calls for significant changes in instruction (NRC, 2012). This study is designed to address two research questions: (1) ‘How do participants describe science teacher leaders’ educational practices for equity?’ and (2) ‘How are science teacher leaders’ equitable practices related to organizational structures and social norms within secondary schools?’. Three data sources: interviews, field observations, and artifacts, were collected and analyzed qualitatively. A social justice leadership framework …

Genetic Counseling For Brca1/2 Mutations: Women’S Experiences, Preferences, And Psychosocial Outcomes Of Counseling, Kate E. Dibble

Doctoral Dissertations

One in 8 women will be diagnosed with breast cancer in her lifetime, but only 5-10% of women who are diagnosed have a BRCA1 and BRCA2 (BReast CAncer) genetic mutation. These mutations naturally occur in biological family units, and women with these mutations live with an increased rate of breast/ovarian cancers. The standard of genetic counseling care is individualized counseling, in which one at-risk family member is tested at a time. A new and potentially more relevant genetic counseling approach, family-based genetic counseling, tests all at-risk family members at one time as one cohesive patient group. The current study explored …

Essays On Farm Productivity: Econometric Evidence From Malawi, Tanzania And Uganda, Jacques C Julien

Doctoral Dissertations

Agricultural productivity is critical for the development of many sub-Saharan African (SSA) countries where the farming sector plays a key role in the economy. An important issue concerns evidence of the inverse relationship between farm size and productivity in developing countries, which has been documented over many decades. Despite the accumulated evidence, this relationship, which has been attributed to a variety of factors, remains a puzzle for development economists.

This dissertation provides new evidence concerning the inverse relationship (IR) hypothesis by addressing several shortcomings found in the literature and applying state-of-the-art stochastic frontier methods, such as the true random effects …

Informing Sexual Assault Prevention With Student-Athletes: Measuring Bystander Intentions And Awareness Of School Policies And Resources, Lorin Tredinnick

Doctoral Dissertations

Student-athletes have been identified as an at-risk population for sexual assault victimization and perpetration. While sexual assault prevention has been effective in increasing student-athlete awareness and response to sexual assault, student-athletes are less likely to see the importance of sexual assault prevention compared to non-athletes. This dissertation seeks to understand student-athlete knowledge and attitudes toward sexual assault prevention. Using the three-article dissertation format, this research is divided into three empirical articles that examine the following: student-athlete barriers to respond to post-sexual assault as prosocial bystanders; student-athlete perceptions of the campus climate and their awareness of sexual assault policies and resources; …

An Economic Analysis Of Smallholder Groundnut Production In Selected African Countries, Jeremy L. Jelliffe

Doctoral Dissertations

Agricultural productivity growth is a primary driver of economic development throughout the world. In Africa, productivity growth has lagged behind the rest of the world, resulting in food shortages and continued reliance on subsistence agriculture by smallholders. The challenges from climate change, population growth, and rural food insecurity, have made it all the more difficult to increase productivity in Africa. In addition, chronic poverty and limited access to resources are major hurdles to regional productivity growth. Initiatives to address these issues rely on foundational studies that are used to justify programs and policy. This dissertation takes a multi-faceted approach and …

Narrating Complexity In Latin America: Jorge Volpi, Roberto Bolaño, Valeria Luiselli, And Daniel Alarcón, Charles R. Lebel

Doctoral Dissertations

This dissertation examines the centrality of complex thought in examples of Latin American narrative produced since 1999. I am interested in the ways in which Jorge Volpi (Mexico City 1968), Roberto Bolaño (Santiago, Chile 1953), Valeria Luiselli (Mexico City 1983), and Daniel Alarcón (Lima, Peru 1977) address complex dynamics in contemporary human experience. My analysis focuses on thematic and narratological indicators of complex thought primarily in Volpi’s En busca de Klingsor (1999); Bolaño’s 2666 (2004); Luiselli’s Los ingrávidos (2011), La historia de mis dientes (2013), and Los niños perdidos (2016); and Alarcón’s podcast Radio Ambulante. I have chosen these …

Finding Critical And Gradient-Flat Points Of Deep Neural Network Loss Functions, Charles Gearhart Frye '09

Doctoral Dissertations

Despite the fact that the loss functions of deep neural networks are highly non-convex, gradient-based optimization algorithms converge to approximately the same performance from many random initial points. This makes neural networks easy to train, which, combined with their high representational capacity and implicit and explicit regularization strategies, leads to machine-learned algorithms of high quality with reasonable computational cost in a wide variety of domains.

One thread of work has focused on explaining this phenomenon by numerically characterizing the local curvature at critical points of the loss function, where gradients are zero. Such studies have reported that the loss functions …

The Impact Of Middle School Scheduling Practices On Adolescent Math Achievement In Louisiana Public Schools, Deborah Lynn Gegg

Doctoral Dissertations

Research on middle-level schools and student achievement revealed a drop in academic performance when students transitioned from elementary school to a traditional middle school. In the United States, the middle school years have historically seen a decline in student achievement following a transition from elementary school.

According to the National Center for Education Statistics, the performance of United States eighth-grade students in mathematics continued to lag behind globally based on the 2015 Trends in International Mathematics and Science Study (U.S. Department of Education, 2017). Specifically, United States eighth graders were ranked 12th in mathematics, which was three notches down from …

Semiconductor Nanocrystals: Synthesis, Optical Properties And Environmental Impact, Xudong Wang

Doctoral Dissertations

The study in this dissertation mainly focused on semiconductor nanocrystals ranging from controllable synthesis of II-VI quantum dots in both organic phase and aqueous phase, to their optical property and potential environmental impact. Besides, our study of fluorescent nanomaterials was extended from semiconductor nanocrystals to another system, carbon dots. In the first project, an unconventional method to induce anisotropic growth of CdS arms on CdSe/CdS seeds was developed to form nanotetrapods. Our control experiments suggested the key role of CdS shell thickness of CdSe/CdS seeds and concentration of precursor for CdS growth in the growth of nanotetrapods. Our results show …

Philippine Jesuit Schools Of Education: Heroic Institutions Of Learning And Leadership In Mission, Joaquin Jose Mari Casimiro Sumpaico

Doctoral Dissertations

Philippine Jesuit schools of education are important training sanctuaries for future teachers. These schools help build a nation by nurturing educators in their student years so that these said teacher-students may be equipped as they pursue their vocation of journeying with the Philippine youth towards meaningful and heroic learning. There is limited research on these Philippine Jesuit schools of education and how these have created an impact in Philippine nation-building. The qualitative research draws attention to the four pillars of Heroic Leadership in these schools of education. It will look for practices of Self-awareness, Ingenuity, Love, and Heroism in the …

Investigation Of The Protein-Membrane Interactions Of The Tim23 Channel Subunit, Melissa Brundin

Doctoral Dissertations

Mitochondria acquire the vast majority of their proteins from the cell cytosol in a manner that requires the coordinated function of numerous translocation machineries embedded within their two membrane systems. One of the most multifaceted of these machineries is the Translocase of the Inner Membrane 23 (TIM23) complex, which mediates the import of both inner membrane- and matrix-targeted proteins. The central subunit of this complex is Tim23, a voltage-gated channel-forming protein that constitutes part of the protein-conducting channel residing in the inner membrane. Tim23 has bipartite domain organization with a C-terminal integral membrane domain and an N-terminal intrinsically disordered domain …

Multi-Scale Modeling Of Nanoparticle-Mediated Drug Delivery, Zhiqiang Shen

Doctoral Dissertations

Using multi-scale molecular dynamics (MD) simulations, we systematically study the influences of nanoparticle (NP) properties (including size, shape, elasticity and surface functionality) on the endocytosis process. Furthermore, we use MD simulations to help design new liposome-like and pH-responsive NPs.

The endocytosis of elastic NPs is first investigated. With a new developed elastic NP model, we investigate NPs with different sizes, shapes, and stiffness. Our simulations provide clear evidence that the membrane wrapping efficiency of NPs is a result of competition between receptor diffusion kinetics and thermodynamic driving force. We further suggest that conflicting experimental observations on the endocytosis efficiency of …

The Impact Of Menstrual Cycle Phase And Sex On Outcomes Related To Hydration Interventions, Gabrielle Giersch

Doctoral Dissertations

Archival abstract submitted

The Neurogenic Fate Potential Of Opcs, Linda Boshans

Doctoral Dissertations

Archival abstract submitted

Dynamic Resource Management In Lossy Real-Time Wireless Networks, Tao Gong

Doctoral Dissertations

Along with the rapid development of real-time wireless network (RTWN) technologies in a wide range of time- and safety-critical industrial applications, packet scheduling algorithms have been playing a critical role in RTWNs to achieve desired Quality of Service (QoS) for real-time sensing and control, especially in the presence of unexpected disturbances. Most existing solutions focus on communication schedule construction to meet the desired QoS but have common assumptions that all wireless links are reliable, and the network topologies are prior known. Although these assumptions simplify the algorithm design and analysis, they are not realistic in real world.

To relax the …