Physical Sciences and Mathematics Commons^™

Molecular Level Characterization Of Dissolved Organic Matter Integrating Trapped Ion Mobility Spectrometry And Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Dennys Leyva Bombuse

FIU Electronic Theses and Dissertations

Dissolved organic matter (DOM) is an extremely complex mixture of organic molecules ubiquitous in aquatic systems and a critical component of the global carbon cycle. Little is known about DOM structural composition at the molecular level. The work presented in this dissertation summarizes the development of a novel analytical toolbox based on trapped ion mobility spectrometry and Fourier transform ion cyclotron resonance mass spectrometry (TIMS-FT-ICR MS) that has significantly contributed to expand our knowledge of DOM molecular complexity and diversity. The TIMS-FT-ICR MS/MS analysis provided for the first-time lower and upper estimation of the molecular isomeric diversity. The TIMS-FT-ICR MS/MS …

A Numerical Investigation Of Tornado Production And Intensification In Tropical Cyclones, Marco Paredes

FIU Electronic Theses and Dissertations

The environmental conditions required for tornado formation and development in tropical cyclones (TCs) and the mechanisms underlying the intensification of TC tornadoes remain poorly understood. Previous research has suggested that low and mid-level dry air intrusion in TCs may enhance convective instability and influence the production of tornadoes. However, observations have their limitations in answering some of the key questions regarding the relationship among thermodynamic instability, dry air, and TC tornado genesis, development, and dissipation. In this study, a multiple nested Weather Research and Forecasting (WRF) model in a hindcasting mode is used to simulate Hurricane Ivan (2004) by resolving …

Allosteric Mechanism On Dream Dimerization And Impact On Its Interactions With Divalent Metal Zn2+, Maria D. Santiago Estevez

FIU Electronic Theses and Dissertations

DREAM belongs to the NCS family, and it is involved in several physiological processes mediated by Ca²⁺ association, which produces changes in its oligomerization state. The mechanism of how Ca²⁺ binds to DREAM remains unknown. A kinetic study of the binding of Ca²⁺ to DREAM suggested that DREAM dimerization is a two-step process, the first step( τ₁= 8±0.1ms) is associated with the binding of Ca²⁺ to the monomer, while the second step (τ₂ = 3.6 ±0.4 s ) corresponds to a conformation relaxation that leads to the dimerization. Furthermore, by analyzing the fast …

Assessment Of The Toxicity Of Legacy And Next-Generation Perfluoroalkyl Substances (Pfas) In Early-Life Stages Of Freshwater And Marine Fish, Kiflom Gebreab

FIU Electronic Theses and Dissertations

Per- and polyfluoroalkyl substances (PFASs) are a group of synthetic surfactants that have utilized for several decades in a wide range of industrial and manufacturing applications. Owing to their high chemical stability, PFAS are widespread and persistent in the environment, and have been shown to be bioaccumulative in diverse organisms including plants, wildlife, and humans. Exposure to PFASs has been linked to a range of documented toxic and/or adverse effects in relation to human and animal health. The potential environmental health and ecotoxicity of next-generation PFAS remain unclear. In the present study, toxicity, and bioconcentration potential, of several perfluoroether carboxylic …

An Evolutionary Optimization Algorithm For Automated Classical Machine Learning, Leila Zahedi

FIU Electronic Theses and Dissertations

Machine learning is an evolving branch of computational algorithms that allow computers to learn from experiences, make predictions, and solve different problems without being explicitly programmed. However, building a useful machine learning model is a challenging process, requiring human expertise to perform various proper tasks and ensure that the machine learning's primary objective --determining the best and most predictive model-- is achieved. These tasks include pre-processing, feature selection, and model selection. Many machine learning models developed by experts are designed manually and by trial and error. In other words, even experts need the time and resources to create good predictive …

Study Of The Etaprimepi0 System In Gluex, Rupesh Dotel

FIU Electronic Theses and Dissertations

The η′π is an important decay channel for the potentially exotic hybrid meson π1(1600) that has been detected in the COMPASS, VES and E852 experiments. These previous experiments used a charged pion beam as a probe. In contrast, the GlueX experiment is designed to search for the exotic hybrid mesons using a linearly polarized photon beam. This thesis project analyzes the η′π0 system produced in GlueX by the reaction γp → η′π0p. After optimizing the event selection to minimize background contributions, a mass independent partial wave analysis is performed in search of an exotic signature. Within the currently available statistical …

Provenance, Composition And Transport Processes Of Pleistocene-Recent Turbidite Sediments Of The Se Nazca Plate, Odp Site 1232, Kimberly D. Beck

FIU Electronic Theses and Dissertations

A 300 meter sequence of Pleistocene turbidite deposits was recovered on the Nazca Plate at the subducting edge of the Peru-Chile Trench at ODP Site 1232. Analysis of the coarsest particles in the turbidite sequences implies sediment was supplied in some proportion by terrestrial erosion and originated in the coastal, central, and Andean volcanic/magmatic belt which parallels the Southern Chilean coast, and the predominant material type is volcanic. Petrographic and geochemical analyses show that samples from 3 - 140 mbsf contain >43% fresh, angular glass. New calcareous nannofossil biostratigraphy brackets the sediment ages of the upper 288 m of cored …

Climatology Of Rainfall Distribution And Asymmetries Of Tropical Cyclones: A Global Perspective, Oscar Guzman Rey

FIU Electronic Theses and Dissertations

Estimating the magnitude of tropical cyclone (TC) rainfall at different landfalling states is an important aspect of the TC forecast that directly affects the level of response from emergency managers in coastal areas. This research analyses the spatial distribution of the rainfall magnitude in tropical cyclones (TCs) at different stages over global oceans. The research’s central hypothesis is that TC rainfall exhibits distinct features in the long-term satellite dataset due to the evolution of the spatial distribution, radial variation, and asymmetries at the stages before, during, and after landfall. The resulting patterns are analyzed through a statistical approach that takes …

A Bayesian Programming Approach To Car-Following Model Calibration And Validation Using Limited Data, Franklin Abodo

FIU Electronic Theses and Dissertations

Traffic simulation software is used by transportation researchers and engineers to design and evaluate changes to roadway networks. Underlying these simulators are mathematical models of microscopic driver behavior from which macroscopic measures of flow and congestion can be recovered. Many models are intended to apply to only a subset of possible traffic scenarios and roadway configurations, while others do not have any explicit constraint on their applicability. Work zones on highways are one scenario for which no model invented to date has been shown to accurately reproduce realistic driving behavior. This makes it difficult to optimize for safety and other …

The Role Of Conformational Changes In Viral And Bacterial Protein Functions, Md Lokman Hossen

FIU Electronic Theses and Dissertations

Proteins do versatile work in cells. They require a cascade of structural changes to perform different tasks like binding to the other neighboring biomolecules, transporting small chemicals, activating a chemical reaction, etc. The structural conformations of proteins can be critical in changing their working ability. In this dissertation, I investigated the role of conformational changes of viral protein, e.g., spike and envelope protein of SARS-CoV-2, and bacterial protein, e.g., multidrug transporter and toxic extrusion protein- PfMATE from Pyrococcus furiosus. Also, I performed molecular docking-based drug screening targeting the E protein to suggest a set of drugs that can be repurposed …

Synthesis, Structure-Activity And Mechanism Studies Of Poly(Guanylurea)S Against Mycobacteria, Michelle M. Miranda

FIU Electronic Theses and Dissertations

Tuberculosis (TB) continues to be a serious threat worldwide, especially in developing countries. Current first-line treatment for TB infections is a multidrug regimen for 4-9 months; if not taken as prescribed, drug-resistant TB can emerge. Novel drugs with unconventional targets are warranted to lessen the lengthy and four-drug treatment. Antimicrobial polymers mimicking naturally occurring antimicrobial peptides (AMPs) have gained much attention due to their enzymatic stability, tunability, cost-effectiveness, and unique mode of action - directly or indirectly - on bacterial membrane. However, selectivity and toxicity have limited their biological applications. Previously, our group synthesized a novel class of antimicrobial polymers, …

Anomaly Detection In Sequential Data: A Deep Learning-Based Approach, Jayesh Soni

FIU Electronic Theses and Dissertations

Anomaly Detection has been researched in various domains with several applications in intrusion detection, fraud detection, system health management, and bio-informatics. Conventional anomaly detection methods analyze each data instance independently (univariate or multivariate) and ignore the sequential characteristics of the data. Anomalies in the data can be detected by grouping the individual data instances into sequential data and hence conventional way of analyzing independent data instances cannot detect anomalies. Currently: (1) Deep learning-based algorithms are widely used for anomaly detection purposes. However, significant computational overhead time is incurred during the training process due to static constant batch size and learning …

Synthesis Of Phenyl Carbamoylated Guanidine Functionalized Chitosan, Eduardo Hernandez Requejo

FIU Electronic Theses and Dissertations

The lack of solubility of the chitosan in organic solvents hinders its potential for chemical modifications. For this reason, it was hypothesized that the insertion of the phenyl carbamoylated guanidine moiety could lead to increased solubility in DMSO and new potential modifications and uses.

This research involved the synthesis of S-methyl phenyl carbamoylated guanidine (SMPCG) starting from the commercially available S-methyl isothiourea. This was followed by the reaction of the SMPCG with chitosan to yield phenyl carbamoylated guanidine functionalized chitosan (PCGCs) with a degree of substitution of 14%.

The chitosan derivative is fully soluble in DMSO and partially in DMF. …

Modified Guanidine-Containing Polymers For Intracellular Protein Delivery, Alfonso Barrios

FIU Electronic Theses and Dissertations

Protein-based therapeutics have gained significant attention for treating or curing various diseases, especially those untreatable by small molecule-drugs. Despite their widespread success and adoption, the cellular membrane remains a major obstacle for proteins to reach the inner compartments of the cell and have had limited applicability spanning only extracellular targets. Consequently, the efficient intracellular delivery of proteins offers tremendous potential to reach new, unexplored, and otherwise “undruggable” targets. Acknowledging the therapeutic need, research efforts aimed at facilitating the delivery of proteins using polymer-based nanoparticles have emerged.

Guanidine-containing polymers provide a promising platform to address the common hurdles associated with protein …

Crude Oil Characterization Using Gas Chromatography, Ion Mobility Spectrometry And Mass Spectrometry, Clement A. Olanrewaju

FIU Electronic Theses and Dissertations

The characterization of crude oils at the compositional level remains challenging due to their high chemical complexity and isomeric diversity. The present work expands the analytical separation space of chemical components in crude oils by coupling gas chromatography (GC), trapped ion mobility spectrometry (TIMS), and mass spectrometry (GC-TIMS-MS and TIMS-FT-ICR MS) for the effective separation and identification of isomeric compounds. The coupling of GC and TIMS-MS platform enhanced the peak capacity and showed complementary isomeric separation. The combination of GC-TIMS-MS and GC-EI-MS technique provided a comprehensive characterization of PAHs and similar compounds from crude oils on the basis of retention …

Integrating Cultural Knowledge Into Artificially Intelligent Systems: Human Experiments And Computational Implementations, Anurag Acharya

FIU Electronic Theses and Dissertations

With the advancement of Artificial Intelligence, it seems as if every aspect of our lives is impacted by AI in one way or the other. As AI is used for everything from driving vehicles to criminal justice, it becomes crucial that it overcome any biases that might hinder its fair application. We are constantly trying to make AI be more like humans. But most AI systems so far fail to address one of the main aspects of humanity: our culture and the differences between cultures. We cannot truly consider AI to have understood human reasoning without understanding culture. So it …

The Valence Quark Structure Of The Nucleon, Christopher A. Leon

FIU Electronic Theses and Dissertations

The nucleon is a composite object, formed from a sea of quarks, anti-quarks and gluons being continuously created and annihilated. Among this complexity, however, there are three valence quarks that give the nucleon its baryon and flavor numbers. Here we investigate the dynamical structure of valence quarks inside the nucleon. The primary tool used will be patron distribution functions (PDFs), which give the distribution of momentum fraction, x, of the quarks and gluons inside the nucleon. By examining the PDFs of the valence quarks from phenomenological fits, we derive a new model-independent relation of PDF peaks and connect it to …

Hydrologic Properties Of Mangrove And Sawgrass Peat In Shark River Slough, Everglades, Florida, Nicole Cordoba

FIU Electronic Theses and Dissertations

Peat sediments are the foundation of most wetlands, acting as a medium for water to flow through, governed by hydraulic conductivity, and as a potential source of nutrients. Shark River Slough is a known, main fresh waterway for Everglades National Park, distributing essential nutrients and freshwater into the wetland. Hydraulic conductivity was calculated through experimental (both in situ water and higher salinity water) falling head tests performed on mangrove and sawgrass peat cores. Nutrient concentrations were analyzed for the pore water released during hydrologic testing. Hydraulic conductivity values were higher in the sawgrass peat than the mangrove peat. No significant …

Intelligent Data Analytics Using Deep Learning For Data Science, Maria E. Presa Reyes

FIU Electronic Theses and Dissertations

Nowadays, data science stimulates the interest of academics and practitioners because it can assist in the extraction of significant insights from massive amounts of data. From the years 2018 through 2025, the Global Datasphere is expected to rise from 33 Zettabytes to 175 Zettabytes, according to the International Data Corporation. This dissertation proposes an intelligent data analytics framework that uses deep learning to tackle several difficulties when implementing a data science application. These difficulties include dealing with high inter-class similarity, the availability and quality of hand-labeled data, and designing a feasible approach for modeling significant correlations in features gathered from …

The Patterns Of Occurrence, Management, And Behavioral Ecology Of Fish Spawning Aggregations In Southeast Florida, Benjamin Binder

FIU Electronic Theses and Dissertations

The formation of fish spawning aggregations (FSAs) is an essential life history process for more than 150 species worldwide. Decades of research have provided a wealth of information to describe FSA dynamics, but there are many regions where their occurrence, behavior, and susceptibility to environmental variation remain uncharacterized. Even in regions that host an extensive research infrastructure such as South Florida, a standardized survey program to locate, validate, and monitor FSAs has not been established. This dissertation addresses those shortcomings in several ways. First, I present a comprehensive synthesis of available FSA literature from the region, which was combined with …

The Utilization Of Volatile Organic Compounds And Human Leukocyte Antigen Genes For Ethnic-Specific Differentiation Within Target Populations, Alice Breia Boone

FIU Electronic Theses and Dissertations

Human scent has been previously defined as a complex mixture of volatile organic compounds (VOCs) detected in the headspace above a scent sample. Humans generate odor from several areas of the body including hair, mouth, hand, axillae, and foot. Due to the novelty of human scent research, human scent evidence has been undervalued in the court of law. However, this type of evidence has significant value when physical evidence is not available at crime scenes. To increase the individualization and differentiation power of human scent evidence, this study aimed to further investigate the identification of chemical signatures within axillae of …

Communicating With Culture: How Humans And Machines Detect Narrative Elements, Wolfgang Victor H. Yarlott

FIU Electronic Theses and Dissertations

To understand how people communicate, we must understand how they leverage shared stories and all the knowledge, information, and associations contained within those stories. I examine three classes of narrative elements that convey a wealth of cultural knowledge: Propp's morphology, motifs, and discourse structure. Propp's morphology communicates how roles and actions drive a narrative forward; motifs fill those roles and actions with specific, remarkable events; discourse groups these into a coherent structure to convey a point.

My thesis has three aims: first, to demonstrate that people can reliably detect and identify all three of these narrative elements; second, to develop …

Development Of A Microwave-Based Dna Extraction Method To Increase The Success Of Direct And Rapid Pcr Technique, Fabiana Taglia

FIU Electronic Theses and Dissertations

The goal of this project was to develop a fast, microwave-based extraction technique that could be employed for direct and rapid DNA analysis. The hypothesis was that the use of a microwave could increase the yield of DNA by opening the cell membrane, rendering the DNA available without the use of any other chemical treatment, and improving results from very low quantity samples.

At present rapid human DNA analysis is mainly restricted to genotyping saliva and sometimes blood samples. We hypothesized that microwave processing could expand the types of samples assessable to these procedures and increase sensitivity.

There were two …

Detecting The Emotions Of Animate Beings In Narrative, Samira Zad

FIU Electronic Theses and Dissertations

Identifying emotions as expressed in text (a.k.a. text emotion recognition) has received a lot of attention over the past decade. Narratives often involve a great deal of emotional expression, and so emotion recognition on narrative text is of great interest to computational approaches to narrative understanding. The meaning and impact of narratives is strongly bound up with the emotions expressed therein. Emotions may be experienced by characters in a story (which may include the narrator), by a story-external narrator, or by the reader. There has been so far two separate streams of work relevant to this observation: (1) emotion detection, …

An Investigation To Corroborate Volatile And Biological Profiles Of Human Odor For Forensic Subject Identification, Chantrell J.G. Frazier

FIU Electronic Theses and Dissertations

Hands are an integral part in transferring complex microbial communities to and from our surroundings. As a result, hands are significant in provenance investigations as specific microbiota can be deposited on everyday objects through touch interactions. Skin microbiome, including bacteria, fungi, and viruses, are unique to each person, and this ‘uniqueness’ can be exploited and applied to forensic identification. Skin microbiota and volatile organic compounds (VOCs) are closely related due to specific bacteria breaking down non-volatile organic compounds to volatile organic compounds that are characteristically present in human scent. However, analyses of microbiota from touch interactions have proven to be …

Do Home Invasion Serial Killers Warrant A Distinct Classification From Other Serial Killer Location Types? A Retrospective Comparative Examination, Caroline V. Comerford

FIU Electronic Theses and Dissertations

This dissertation seeks to address the research gap in serial homicide regarding home invasion serial killers (HISKs) and add to existing policy by providing insight and approaches to assist in serial murder investigations of such killers. Data for the study was obtained from the 2019 Radford University/Florida Gulf Coast University Serial Killer Database (RU/FGCU SKD) and additional public information searches. A retrospective comparative design and proportionate stratified random sampling of 326 serial killers from the RU/FGCU SKD (2019) were used to examine the differences and classifications of HISKs and non-home invasion serial killers (non-HISKs) in three investigations: (1) common characteristics; …

Examining The Effects Of Individual And Neighborhood Factors On Hiv Transmission Risk Potential Among People With Hiv, Semiu Olatunde Gbadamosi

FIU Electronic Theses and Dissertations

HIV transmission risk significantly increases in late-diagnosed HIV and at HIV viral load (VL) >1500 copies/mL. The objective of this dissertation was to examine factors associated with HIV transmission risk potential for persons with HIV (PWH) using measures of time from HIV infection to diagnosis and trajectories of VL suppression. Additionally, we sought to determine whether a single yearly VL measure—the current standard to track the HIV epidemic in the United States—is reliable in assessing viral suppression for PWH. The first study estimated the distribution of time from HIV infection to diagnosis in Florida using a CD4 depletion model and …

A Machine Learning Framework For Identifying Molecular Biomarkers From Transcriptomic Cancer Data, Md Abdullah Al Mamun

FIU Electronic Theses and Dissertations

Cancer is a complex molecular process due to abnormal changes in the genome, such as mutation and copy number variation, and epigenetic aberrations such as dysregulations of long non-coding RNA (lncRNA). These abnormal changes are reflected in transcriptome by turning oncogenes on and tumor suppressor genes off, which are considered cancer biomarkers.

However, transcriptomic data is high dimensional, and finding the best subset of genes (features) related to causing cancer is computationally challenging and expensive. Thus, developing a feature selection framework to discover molecular biomarkers for cancer is critical.

Traditional approaches for biomarker discovery calculate the fold change for each …

In Silico Identification Of Vaccine Candidates Against Viral Infections, Prabin Baral

FIU Electronic Theses and Dissertations

There are many viral diseases without effective treatments or vaccines. These viruses can cause catastrophic epidemics such as the Lassa, Ebola, and Marburg viruses. Similarly, the recent coronavirus pandemic is of great concern as new variants are continuously emerging with decreased susceptibility to antibodies and vaccines that were developed for earlier strains. A critical step in the immune system’s fight against viruses involves an immunological protein molecule binding to a viral protein molecule. I investigate the atomic and molecular details of binding site recognition and binding interactions and dynamics for three important viruses.

Antigens are molecules, such as viral proteins, …

Volitional Control Of Lower-Limb Prosthesis With Vision-Assisted Environmental Awareness, S M Shafiul Hasan

FIU Electronic Theses and Dissertations

Early and reliable prediction of user’s intention to change locomotion mode or speed is critical for a smooth and natural lower limb prosthesis. Meanwhile, incorporation of explicit environmental feedback can facilitate context aware intelligent prosthesis which allows seamless operation in a variety of gait demands. This dissertation introduces environmental awareness through computer vision and enables early and accurate prediction of intention to start, stop or change speeds while walking. Electromyography (EMG), Electroencephalography (EEG), Inertial Measurement Unit (IMU), and Ground Reaction Force (GRF) sensors were used to predict intention to start, stop or increase walking speed. Furthermore, it was investigated whether …