Digital Commons Network^™

A Comparative Genomics Exploration Of Inter-Partner Metabolic Signaling In The Coral-Algal Symbiosis, Katherine E. Dougan

FIU Electronic Theses and Dissertations

At the foundation of coral reef ecosystems is the symbiosis between the coral host and its microbial community, particularly its photoautotrophic algae from the family Symbiodiniaceae. As a symbiosis centered around nutritional exchange, determining the mechanisms involved in the maintenance of this cooperative exchange is central to understanding how it breaks down. As the nutritional transfer primarily consists of sugars, this work first focuses on the cnidarian insulin signaling pathway, an evolutionarily important metazoan pathway involved in diverse functions, most notably metabolism. This dissertation unveiled 360 putative cnidarian insulin-like peptides (cnILPs) from existing transcriptomic datasets, where they were previously missed …

National Material Capability Buildup And The Rank-Magnitude Distribution Of Wars, Matthew Felice

FIU Electronic Theses and Dissertations

Are there physical laws, rather than conventions like diplomacy, that determine when war will break out and how severe it will be? On the eve of World War II, L. F. Richardson discovered a curious pattern: Major wars are rare and minor wars are common to such a predictable degree that the size-frequency offset can be plotted with a straight line. Complex-systems theorists have since confirmed those findings and tested them with computer models. Yet none of the research has fully synthesized this law-like observation with the established theoretical approaches in international relations that would apply, such as power transition …

Novel High Isolation Antennas For Simultaneous Transmit And Receive (Star) Applications, Alexander Hovsepian

FIU Electronic Theses and Dissertations

Radio frequency (RF) spectrum congestion is a major challenge for the growing need of wireless bandwidth. Notably, in 2015, the Federal Communications Commission (FCC) auctioned just 65 MHz (a bandwidth smaller than that used for WiFi) for more than $40 billion, indicating the high value of the microwave spectrum. Current radios use one-half of their bandwidth resource for transmission, and the other half for reception. Therefore, by enabling radios to transmit and receive across their entire bandwidth allocation, spectral efficiency is doubled. Concurrently, data rates for wireless links also double. This technology leads to a new class of radios and …

Engineering Electromagnetic Systems For Next-Generation Brain-Machine Interface, Brayan Ricardo Navarrete

FIU Electronic Theses and Dissertations

MagnetoElectric Nanoparticles (MENPs) are known to be a powerful tool for a broad range of applications spanning from medicine to energy-efficient electronics. MENPs allow to couple intrinsic electric fields in the nervous system with externally controlled magnetic fields. This thesis exploited MENPs to achieve contactless brain-machine interface (BMIs). Special electromagnetic devices were engineered for controlling the MENPs’ magnetoelectric effect to enable stimulation and recording. The most important engineering breakthroughs of the study are summarized below.

(I) Metastable Physics to Localize Nanoparticles: One of the main challenges is to localize the nanoparticles at any selected site(s) in the brain. The fundamental …

Racial Microaggressions Of Indigenous Undergraduate Students In An Ecuadorian Higher Education Institution, Adriana Cundar Ruano

FIU Electronic Theses and Dissertations

Although subtle, racial microaggressions have an impact on lives of people who endure hostilities by virtue of their race or ethnicity (Solórzano et al., 2000; Sue et al., 2007). Research on racial discrimination indicates that college campuses can be threatening environments especially for underrepresented students who constantly face elusive hostilities in their interactions with teachers, peers, and administrative (Allen, 2010; Helm, 2013; Nadal et al., 2014, Reid, 2017). The current mixed-methods study examined the most commonly experienced types of microaggressions affecting Indigenous undergraduate students while pursuing a bachelor’s degree in a public higher education institution in Ecuador, as well as …

Star Formation In Dwarf Galaxies, Simeon L. Bolds

FIU Electronic Theses and Dissertations

A catalog of neutral hydrogen (HI) of nearby dwarf galaxies obtained from the LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey) project along with ancillary data are used to examine the relative importance of star-induced star formation associated with the HI holes in 31 dwarf galaxies. HI shells/rings surrounding the HI holes are defined and the fractional amounts of HI and star formation in the rings relative to the global galactic amounts are calculated. These are then compared to look for correlations between the amount of star formation and neutral hydrogen in the rings. Two …

Bioscaffold Valve With And Without Mechanically Conditioned Stem Cells For The Treatment Of Critical Mitral Valve Diseases In The Young, Brittany A. Gonzalez

FIU Electronic Theses and Dissertations

Congenital heart disease, which includes heart valve defects, are the most common type of birth abnormality in the US. Infants with critical congenital valve disease have no established treatment-measure other than compassionate care options, owing to an absence of prosthetic valves in small sizes and their inability to support somatic growth. A regenerable valve would be appealing since these barriers could be overcome; it can potentially provide for growth, self-repair, infection resistance and be a permanent approach for replacing defective heart valves.

Porcine small intestinal submucosa (PSIS) bioscaffold was used to create valvular constructs with the possibility to grow overtime. …

Strategies To Identify And Mitigate Secondary Crashes In Real-Time, Angela Kitali

FIU Electronic Theses and Dissertations

Traffic incidents are the primary source of non-recurring congestion. In addition to affecting roadway operations, traffic congestion resulting from an incident exposes other vehicles to the risk of being involved in additional incidents, typically referred to as secondary crashes. Secondary crashes adversely affect traffic operations and impose risk on the safety of both road users and incident responders. Transportation agencies have been looking for ways to mitigate secondary crashes. However, secondary crash mitigation has several challenges. The length of the queue caused by an initial incident and the amount of time this queue lasts on the road varies, depending on …

Bacterial Mechanisms Of Toxicity And Resistance To Organoarsenicals, Luis D. Garbinski

FIU Electronic Theses and Dissertations

Arsenic is a toxic element prevalent in the environment since the origin of life on Earth. Bacteria evolved in an arsenic-rich environment, where they developed ways to both overcome arsenic toxicity and harness it to compete with other organisms. These mechanisms include chemical modifications (e.g. oxidation, methylation), degradation, and efflux. The goal of this dissertation is to better characterize these mechanisms, illuminating the arsenic biogeocycle and allowing us to harness organoarsenical toxicity for novel antibiotics. A goal of my research was to elucidate the antibiotic properties of MAs(III), which is synthesized by bacteria to thrive over other bacteria, by identifying …

Microphysical-Dynamical Interaction In Tropical Cyclone Intensification, Zongyao Yang

FIU Electronic Theses and Dissertations

Producing timely and accurate tropical cyclone (TC) intensity forecasts remains one of the most difficult challenges facing meteorologists today. The state-of-the-art three-dimensional (3D) full physics operational models, in particular, have problems in simulating rapid intensification (RI), a situation where a TC intensifies dramatically in a short period of time. For example, Hurricanes Patricia (2015) and Maria (2017) increased their maximum sustained winds by 90 knots and 70 knots within 24 hours, respectively. The major objectives of this dissertation are to (a) explore the underlying reasons why the Hurricane Weather Research and Forecasting (HWRF) system, one of the operational models used …

Fronteras Hispánicas: Identidades Fronterizas Y Diálogo Intercultural En La Literatura Y El Cine Contemporáneos, Claudia Battistel

FIU Electronic Theses and Dissertations

Border-crossings —both geographical and metaphorical— are a fertile territory for critical and fictional discourses that explore the forging of gendered personal, social, and cultural identities. The notion of the border becomes a political, material, discursive or symbolic limit, a space of conflict, resistance and negotiation, where power relations are articulated. In this dissertation I analyze the following border-crossing narratives and films: The House on Mango Street, by Sandra Cisneros; Jo també soc catalana and El último patriarca, by Najat El Hatchmi; Retorno a Hansala, by Chus Gutiérrez, and Sin dejar huella, by María Novaro. My study …

Photo-Production Of Eta Mesons, Mahmoud Mohamed Kamel

FIU Electronic Theses and Dissertations

In this work we present the GlueX experiment extensive high statistics measurements of the η meson photo-production differential cross sections at beam energies between 3 GeV and 11.6 GeV. We compared the low energy (2.9 GeV< Eγ < 5.9 GeV) differential cross section (dσ/dΩ) results to previous experimental results from the Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS) collaboration. These (dσ/dΩ) results are also compared to the theoretical isobar model EtaMAID2018 by Tiator et. al., and the Regge model by Nys et. al. The differential cross section dσ/dt is also presented and compared to the previous experimental results, and to the above models, in addition to a model by J. M. Laget. The high energy (6.2 GeV< Eγ < 11.6 GeV) cross section results (dσ/dΩ, and dσ/dt) are compared to the isobar model EtaMAID2018. These results will provide new constraints on η photo-production mechanisms and high energy t- channel processes.

Digital And Mixed Domain Hardware Reduction Algorithms And Implementations For Massive Mimo, Najath A. Mohomed

FIU Electronic Theses and Dissertations

Emerging 5G and 6G based wireless communications systems largely rely on multiple-input-multiple-output (MIMO) systems to reduce inherently extensive path losses, facilitate high data rates, and high spatial diversity. Massive MIMO systems used in mmWave and sub-THz applications consists of hundreds perhaps thousands of antenna elements at base stations. Digital beamforming techniques provide the highest flexibility and better degrees of freedom for phased antenna arrays as compared to its analog and hybrid alternatives but has the highest hardware complexity.

Conventional digital beamformers at the receiver require a dedicated analog to digital converter (ADC) for every antenna element, leading to ADCs for …

A Multimodal Neuroimaging Approach For Classification And Prediction Of Alzheimer's Disease Using Machine Learning, Parisa Forouzannezhad

FIU Electronic Theses and Dissertations

Alzheimer’s disease (AD) is one of the most common neurodegenerative disorders among the elderly population. It is progressive, irreversible in nature, and is considered the main cause of dementia. AD has become a world health problem affecting developed and developing nations alike, with the number of diagnosed AD patients increasing rather dramatically as both the life span of humans and the earth’s population continue to increase. Therefore, AD diagnosis in its earliest manifestations, preferably at the presymptomatic stage is critical for the timely planning of treatment and therapeutic interventions. We introduce new machine learning algorithms to detect and predict Alzheimer’s …

Data Analytic Approach To Support The Activation Of Special Signal Timing Plans In Response To Congestion, Mosammat Tahnin Tariq

FIU Electronic Theses and Dissertations

Improving arterial network performance has become a major challenge that is significantly influenced by signal timing control. In recent years, transportation agencies have begun focusing on Active Arterial Management Program (AAM) strategies to manage the performance of arterial streets under the flagship of Transportation Systems Management & Operations (TSM&O) initiatives. The activation of special traffic signal plans during non-recurrent events is an essential component of AAM and can provide significant benefits in managing congestion.

Events such as surges in demands or lane blockages can create queue spillbacks, even during off-peak periods resulting in delays and spillbacks to upstream intersections. To …

Defense By Deception Against Stealthy Attacks In Power Grids, Md Hasan Shahriar

FIU Electronic Theses and Dissertations

Cyber-physical Systems (CPSs) and the Internet of Things (IoT) are converging towards a hybrid platform that is becoming ubiquitous in all modern infrastructures. The integration of the complex and heterogeneous systems creates enormous space for the adversaries to get into the network and inject cleverly crafted false data into measurements, misleading the control center to make erroneous decisions. Besides, the attacker can make a critical part of the system unavailable by compromising the sensor data availability. To obfuscate and mislead the attackers, we propose DDAF, a deceptive data acquisition framework for CPSs' hierarchical communication network. Each switch in the hierarchical …

Geographic Data Mining And Knowledge Discovery, Liangdong Deng

FIU Electronic Theses and Dissertations

Geographic data are information associated with a location on the surface of the Earth. They comprise spatial attributes (latitude, longitude, and altitude) and non-spatial attributes (facts related to a location). Traditionally, Physical Geography datasets were considered to be more valuable, thus attracted most research interest. But with the advancements in remote sensing technologies and widespread use of GPS enabled cellphones and IoT (Internet of Things) devices, recent years witnessed explosive growth in the amount of available Human Geography datasets. However, methods and tools that are capable of analyzing and modeling these datasets are very limited. This is because Human Geography …

Investigation Of Dna Damage And Genomic Organization In The Cellular Response To Platinum Chemotherapy, Abdulhadi Abdulwahed

FIU Electronic Theses and Dissertations

Ovarian cancer (OC) is the primary reason for gynecological cancer-related deaths among women. This cancer rarely has specific symptoms making early detection challenging. Platinum compounds have been used as the first-line treatment for OC. However, OC patients often develop chemoresistance to current platinum/taxane chemotherapy regimens upon recurrence, leaving patients with no alternative treatment options. The purpose of this thesis was to investigate the molecular basis of chemoresistance in OC by analyzing the damage of DNA response and gene positioning after treatment exposure. A modified comet assay was used to measure interstrand cross-link (ICL) formation and repair in chemoresistant (CR) (SKOV-3) …

The Power Of Presumed Trauma And The Perpetuated Yet Unintentional Silence In Henry James' The Turn Of The Screw, Andria E. Rivero

FIU Electronic Theses and Dissertations

Henry James’ The Turn of the Screw (1898) has long been a work capable of numerous interpretations and readings centering around the lead character, the governess, and her intentions and interactions in the novella. However, this thesis explores the extent of the governess’s actions and power and their results towards the children for which she is responsible. In this thesis, I focus on the presence of trauma as presumed by the adult characters, perpetuating unintentional limitations on the children who are assumed to be traumatized. The thesis uses trauma studies to understand power dynamics within the novella. The power dynamics …

Numerical Modeling And Conjugate Heat Transfer Analysis Of Single U-Tube Vertical Borehole Heat Exchangers, Talha Khan

FIU Electronic Theses and Dissertations

The primary purpose of this thesis was to develop a design for improving the efficiency of the vertical type single u-tube borehole heat exchanger. A thorough literature review of the various existing analytical and numerical models of the borehole heat exchanger (BHEs) was performed and numerical modeling of the BHE was conducted to solve the conjugate heat transfer problem in the BHE in 3D using ANSYS Fluent 2019 R1. A comparison between the results obtained using various mesh sizes, types, different turbulence models showed the independence of the parameters on the numerical simulation results.

From the numerical simulation, it was …

A Structural Equation Model Analysis Of Computing Identity Sub-Constructs And Student Academic Persistence, Mohsen Taheri

FIU Electronic Theses and Dissertations

This dissertation explores the impact of computing identity sub-constructs on the academic persistence of computing students. This research provides models, quantified relationships, and insights to increase the number of graduates with the intention of pursuing a career in computing. Despite the growing significance of computer science and all the projected new jobs in computer science, many university and college programs suffer from low student persistence rates. One theoretical framework used to better understand persistence in other STEM disciplines is disciplinary identity. Disciplinary identity refers to how students see themselves with respect to a discipline. This study examines the effects of …

Children's Creative Processes In Music Composition Through The Orff-Schulwerk Approach, Ashley Viera Espinal

FIU Electronic Theses and Dissertations

The purpose of this descriptive qualitative study was to explore the creative processes of elementary school students in music composition through the Orff-Schulwerk approach. Twenty-two 5th grade students and a music teacher with all three levels of the Orff-Schulwerk certification participated in the study. There were three main focal points that were investigated within a span of five-weeks: 1) children’s creativity in an Orff-based composition task, 2) children’s perceptions of their creative processes employed during the composition task, and 3) the teacher’s perceptions of teaching/learning music composition through the Orff-Schulwerk approach. Data were generated through observations, field notes, interviews with …

Efficient, High Power Density, Modular Wide Band-Gap Based Converters For Medium Voltage Application, Hadi Moradisizkoohi

FIU Electronic Theses and Dissertations

Recent advances in semiconductor technology have accelerated developments in medium-voltage direct-current (MVDC) power system transmission and distribution. A DC-DC converter is widely considered to be the most important technology for future DC networks. Wide band-gap (WBG) power devices (i.e. Silicon Carbide (SiC) and Gallium Nitride (GaN) devices) have paved the way for improving the efficiency and power density of power converters by means of higher switching frequencies with lower conduction and switching losses compared to their Silicon (Si) counterparts. However, due to rapid variation of the voltage and current, di/dt and dv/dt, to fully utilize the advantages of the Wide-bandgap …

Production And Characterization Of Twelve Different Biochars And Evaluating Their Effects On Soil Health And Plant Growth, Shagufta Gaffar

FIU Electronic Theses and Dissertations

Biochar has been a topic of growing interest in the scientific community. It is a product derived from carbon rich organic materials through the process of pyrolysis. It has received wide attention as a means to improve soil fertility and crop productivity, absorb pollutants in soil, and sequester carbon to mitigate climate change. Recent research on biochar explores its impacts on the environment with particular focus on use as a soil amendment in agriculture. Biochar produced from different biomass and under different production process effects the environmental and agronomic impacts of its application in different ways. This means biochar can …

Sensor Approach For Brain Pathophysiology Of Freezing Of Gait In Parkinson's Disease Patients, Juan Sebastian Marquez Jaramillo

FIU Electronic Theses and Dissertations

Parkinson's Disease (PD) affects over 1% of the population over 60 years of age and is expected to reach 1 million in the USA by the year 2020, growing by 60 thousand each year. It is well understood that PD is characterized by dopaminergic loss, leading to decreased executive function causing motor symptoms such as tremors, bradykinesia, dyskinesia, and freezing of gait (FoG) as well as non-motor symptoms such as loss of smell, depression, and sleep abnormalities. A PD diagnosis is difficult to make since there is no worldwide approved test and difficult to manage since its manifestations are widely …

Laboratory And Epidemiological Characteristics Of Zika Virus Infections In Florida, Stephen L. White

FIU Electronic Theses and Dissertations

Until recently, Zika virus (ZIKV) was an obscure virus that rarely caused infections and was unknown to most. In 2015 and 2016, ZIKV came into the public spotlight as Brazil and other countries began to report large increases in infections with ZIKV and reported potential complications with developing fetuses and neurologic manifestations. In 2016, the state of Florida identified and responded to an outbreak of locally acquired ZIKV infections in Miami-Dade County. This dramatic increase in infections demonstrated both its importance as an emerging infectious disease and the paucity of knowledge surrounding ZIKV. This study seeks to utilize the data …

Temporal And Causal Inference With Longitudinal Multi-Omics Microbiome Data, Daniel Ruiz-Perez

FIU Electronic Theses and Dissertations

Microbiomes are communities of microbes inhabiting an environmental niche. Thanks to next generation sequencing technologies, it is now possible to study microbial communities, their impact on the host environment, and their role in specific diseases and health. Technology has also triggered the increased generation of multi-omics microbiome data, including metatranscriptomics (quantitative survey of the complete metatranscriptome of the microbial community), metabolomics (quantitative profile of the entire set of metabolites present in the microbiome's environmental niche), and host transcriptomics (gene expression profile of the host). Consequently, another major challenge in microbiome data analysis is the integration of multi-omics data sets and …

Fundamental Studies Of The Singlet Oxygenation Of Water Soluble Biological And Environmental Important Molecules, Marcela Jaramillo

FIU Electronic Theses and Dissertations

Singlet oxygen, 1O2, can be easily generated by a sensitizer, solar radiation, and molecular oxygen. 1O2 is very important in a range of biological and environmental systems. The products and mechanisms of the 1O2 reactions are well studied in organic solvents, and despite well-established solvent effects, studies on the reactions of the singlet oxygen in aqueous media are limited. Herein, 1O2 reactions with biologically and environmentally relevant conjugated π systems in aqueous solutions are presented. Water-soluble isomeric 1, 3-hexadienes are simple mechanistic probes for the 1O2 reactions since concerted and non-concerted pathways produce distinct products. The isomerization of sorbic acid …

Representations Of A Good Citizen: A Genealogy Of Power And Critical Investigation Of Pictographs, 1937-1942, Joselyn Naranjo

FIU Electronic Theses and Dissertations

The study traced selected knowledge that influenced pictographs in social studies textbooks in the United States from 1937 through 1942. The qualitative study analyzed the messages in pictographs produced by Rudolf Modley’s business - Pictorial Statistics, Incorporated. The study interpreted the underlying ideological management within pictographs to present a method of analysis for future research on other visual educational material. Foucault’s (1980; 2003; Shiner, 1982) genealogy of power method addressed the different shifts in power and meaning making involved in communicating sociopolitical messages to the reader through pictographs while ideological management and governmentality informed Hsieh & Shannon’s (2005) directed content …

Statistical Modeling Of Private Sector Participation In Disaster Risk Reduction Data, Wupeng Yin

FIU Electronic Theses and Dissertations

The impacts of disaster on the private sector are inevitable, but their risks can be managed and reduced by preventively evaluative measures. Disaster risk reduction index (DRRI) and Disaster Experience (DE) variables were investigated in a survey study in six Western Hemisphere cities within the private sector of various business sizes. Our thesis built and evaluated 16 predictive models of DRRI with 36 categorical predictors and N = 1162 observations. Four statistical methods for linear regression and five for classification as well as seven machine learning methods were utilized. We also used stepwise selection and regulation methods for variable selection. …