Digital Commons Network^™

Top-Down And Bottom-Up Approaches To Understanding The Fate Of The Federally Endangered Schaus’ Swallowtail Butterfly (Heraclides Aristodemus Ponceanus), Jaeson T. Clayborn

FIU Electronic Theses and Dissertations

The federally endangered Schaus’ swallowtail butterfly (Heraclides aristodemus ponceanus) populations have declined precipitously over the years. Despite tremendous efforts to augment the numbers of this butterfly through captive-bred releases and habitat enhancements, it remains imperiled and federally endangered. The dissertation’s objectives were: 1) to restore dry forest habitat in Biscayne National Park (BNP) for Schaus’ swallowtails; 2) to assess host plant (torchwood and wild lime) survivorship and growth in the restoration sites (BNP) and project dry forest habitat loss because of imminent sea level rise (SLR); 3) to quantify ant activity and record predator-prey interactions against Heraclides caterpillars …

The Study Of Tissue-Specific Dna Methylation As A Method For The Epigenetic Discrimination Of Forensic Samples, Joana Ap Antunes

FIU Electronic Theses and Dissertations

In forensic sciences, the serological methods used to determine which body fluid was collected from the crime scene are merely presumptive or labor intensive since they rely on protein detection or on microscopic identification of cells. Given that certain forensic cases may need the precise identification of a body fluid to determine criminal contact, such is the example of a suspected sexual assault of a minor; certainty in the body fluid of origin may depict a precise picture of the events. The identification of loci that show differences in methylation according to the tissue of origin can aid forensic analysts …

Selective Sensing Of Ions And Ion Pairs Of Environmental And Forensic Significance, Tosin Mobolaji Jonah

FIU Electronic Theses and Dissertations

Dual-host combinations of cation and anion sensors have unique potential for selective detection of ion pairs, such as NH₄NO₃, via solvent extraction. Selective sensors for NH₄⁺ and NO₃^- were synthesized and used together for ion-pair sensing of ammonium nitrate both in organic solvents (using Bu₄N⁺NO₃ ^- and NH₄⁺PF₆^-) and in extraction of NH₄NO₃ from water into dichloromethane. A fluorescent sensor for NH₄⁺ based on 1,3,5-triethylbenzene shows remarkable binding and sensing selectivity for NH₄⁺ vs. …

A Historical Floristic Inventory Of Pine Rockland Fabaceae (Leguminosae), Adel L. Pena

FIU Electronic Theses and Dissertations

The objectives of this study were to investigate temporal changes in the diversity of pine rockland Fabaceae, induced by anthropogenic factors. Herbarium collections spanning 170 years were used to analyze species frequency and richness. The results indicated temporal fluctuations in diversity with frequency of native species highest previous to the year 1920, and exotic-invasive species richness peaking after the 1960s. The accompanying species list resulting from the inventory included 122 Fabaceae species, in 56 genera, with an additional 19 species not previously listed for pine rocklands. The results emphasize the damage caused by early and deliberate introductions of exotic species, …

Drug Candidate Discovery: Targeting Bacterial Topoisomerase I Enzymes For Novel Antibiotic Leads, Shayna Sandhaus

FIU Electronic Theses and Dissertations

Multi-drug resistance in bacterial pathogens has become a global health crisis. Each year, millions of people worldwide are infected with bacterial strains that are resistant to currently available antibiotics. Diseases such as tuberculosis, pneumonia, and gonorrhea have become increasingly more difficult to treat. It is essential that novel drugs and cellular targets be identified in order to treat this resistance. Bacterial topoisomerase IA is a novel drug target that is essential for cellular growth. As it has never been targeted by existing antibiotics, it is an attractive target. Topoisomerase IA is responsible for relieving torsional strain on DNA by relaxing …

Id3, Estrogenic Chemicals, And The Pathogenesis Of Tumor-Like Proliferative Vascular Lesions, Vincent E. Avecilla

FIU Electronic Theses and Dissertations

Tumor-like proliferative vascular lesions manifest in several diseases such as peripheral arterial disease (PAD) and atherosclerosis (AS) after arterial injury. The cause of the vascular cell dysfunction in PAD patients is not known. Our recent novel discovery shows that inhibitor of differentiation 3 (ID3) is highly expressed in intimal lesions of clinical vascular disease samples. The central hypothesis of our study is: estrogenic chemical induced dysregulation of ID3 target genes is involved in the development of vascular disease. NHANES data analysis demonstrated higher geometric levels of all 6 PCB congeners in both PAD diagnosed participants and participants at risk of …

Transgneic Endothelin 3 Regulates Murine Pigment Production And Coat Color, Javier Pino

FIU Electronic Theses and Dissertations

Pigmentation plays a protective role against damage caused by ultraviolet (UV) irradiation. Humans with fair skin and light hair have a higher susceptibility to UV-induced DNA damage that can lead to the development of skin cancers. The melanocytes found in the skin and hair follicles depend on different signaling molecules for their proper development and pigment production. α-Melanocyte Stimulating Hormone (α-msh) binds to the Melanocortin 1 receptor (Mc1r) to regulate pigment production and the switch between eumelanin and pheomelanin. Lethal yellow mice (A^y) overexpress the agouti signaling protein, which inhibits the binding of α-msh, resulting in a yellow …

Epigenetic Instability Induced By Dna Base Lesion Via Dna Base Excision Repair, Zhongliang Jiang

FIU Electronic Theses and Dissertations

DNA damage can cause genome instability, which may lead to human cancer. The most common form of DNA damage is DNA base damage, which is efficiently repaired by DNA base excision repair (BER). Thus BER is the major DNA repair pathway that maintains the stability of the genome. On the other hand, BER mediates DNA demethylation that can occur on the promoter region of important tumor suppressor genes such as Breast Cancer 1 (BRCA1) gene that is also involved in prevention and development of cancer. In this study, employing cell-based and in vitro biochemical approaches along with bisulfite DNA sequencing, …

The Effect Of Target-Specific Biomolecules In Breast Cancer, Mohannad Garoub

FIU Electronic Theses and Dissertations

Cancer is the second leading cause of mortality in the United States and the World, therefore, early effective prevention, diagnosis, and therapy is needed. Estrogens play a major role in the initiation and progression of breast cancer. Elevated lifetime exposure to estrogens is associated with an increased risk of developing breast cancer. Estrogens through influencing mitochondria contribute to estrogen induced breast carcinogenesis; however, the exact mitochondrial mechanisms underlying the estrogen carcinogenic effect in breast tissue are not clearly understood. For this dissertation, the mitotoxic and cytotoxic effects of triphenylphosphonium cation (TPP) and Origanum majorana organic extract (OME) as well as …

Quorum Sensing Signals Produced By Heterotrophic Bacteria In Black Band Disease (Bbd) Of Corals And Their Potential Role In Bbd Pathogenesis, Chinmayee D. Bhedi

FIU Electronic Theses and Dissertations

Black band disease (BBD) of corals is a temperature dependent, highly virulent, polymicrobial disease affecting reef-building corals globally. The microbial consortium of BBD is primarily comprised of functional physiological groups that include photosynthetic cyanobacteria, sulfate reducers, sulfide oxidizers and a vast repertoire of heterotrophic bacteria. Quorum sensing (QS), the cell-density dependent communication phenomenon in bacteria, is known to induce expression of genes for a variety of virulence factors in diseases worldwide. Microbes capable of QS release signals such as acyl homoserine lactones (AHLs) and autoinducer-2 (AI-2), which coordinate microbial interaction. The focus of the present study was to investigate the …

Protein-Protein Interactions Of Bacterial Topoisomerase I, Srikanth Banda

FIU Electronic Theses and Dissertations

Protein-protein interactions (PPIs) are essential features of cellular processes including DNA replication, transcription, translation, recombination, and repair. In my study, the protein interactions of bacterial DNA topoisomerase I, an essential enzyme, were investigated. The topoisomerase I in bacteria relaxes excess negative supercoiling on DNA and maintains genomic stability. Investigating the PPI network of DNA topoisomerase I can further our understanding of the various functional roles of this enzyme. My study is focused on topoisomerase I of Escherichia coli and Mycobacterium smegmatis. Firstly, we have explored the biochemical mechanisms for an interaction between RNA Polymerase, and topoisomerase I in E. …

Studies Of Nε-Lysine Acetylation Modification On Escherichia Coli Topoisomerase I, Qingxuan Zhou

FIU Electronic Theses and Dissertations

Escherichia coli topoisomerase I (TopA), a regulator of global and local DNA supercoiling, is modified by N^ε-Lysine acetylation. The sirtuin protein deacetylase CobB can reverse both enzymatic and non-enzymatic lysine acetylation modifications. Here, we explored the effect of lysine acetylation on E. coli topoisomerase I through analysis of TopA relaxation activity and protein expression in cell extract of wild-type and a ΔcobB mutant strains. We showed that the absence of deacetylase CobB in a ΔcobB mutant reduced intracellular TopA relaxation activity while elevating TopA expression and topA gene transcripts levels. Acetyl phosphate mediated lysine acetylation decreased the activity …

The Effect Of Vitamin D3 Supplementation On Kidney Function And Cardiovascular Disease Markers Among Hispanics And African Americans With Type 2 Diabetes, Gustavo G. Zarini

FIU Electronic Theses and Dissertations

Serum vitamin D deficiency/insufficiency, Chronic Kidney Disease (CKD) and elevated blood pressure are important health concerns especially among minorities with type 2 diabetes. The effect of vitamin D₃ supplementation (cholecalciferol) at 6,000 IU/day (d) vs. 4,000 IU/d on kidney function and cardiovascular disease markers among Hispanics and African Americans with type 2 diabetes and hypovitaminosis D (/ml) was evaluated. Subjects (n=63) were recruited from two clinics in Miami-Dade County, FL. Fasting venous blood and fresh, single-voided first morning urine samples were collected from each participant by a certified phlebotomist and analyzed by Solstas Lab Partners, Davie, FL. Linear mixed …

Biochemical Characterization Of Arsi: A Novel C-As Lyase For Degradation Of Environmental Organoarsenicals, Shashank Suryakant Pawitwar

FIU Electronic Theses and Dissertations

Organoarsenicals such as methylarsenical methylarsenate (MAs(V)) and aromatic arsenicals including roxarsone (4-hydroxy-3-nitrophenylarsenate or Rox(V)) have been extensively used as an herbicide and growth enhancers in animal husbandry, respectively. They undergo environmental degradation to more toxic inorganic arsenite (As(III)) that contaminates crops and drinking water. We previously identified a bacterial gene (arsI) responsible for aerobic MAs(III) demethylation. The gene product, ArsI, is a Fe(II)-dependent extradiol dioxygenase that cleaves the carbon-arsenic (C-As) bond in MAs(III) and trivalent aromatic arsenicals. The objective of this study was to elucidate the ArsI mechanism. Using isothermal titration calorimetry, we determined the dissociation constants (Kd) and ligand-to-protein …

Identification And Phenotypic Plasticity Of Metastatic Cells In A Mouse Model Of Melanoma, Xiaoshuang Li

FIU Electronic Theses and Dissertations

Melanoma is the deadliest form of skin cancer due to its high propensity to metastasize and resistance to current therapies. We have created a spontaneous mouse model of metastatic melanoma (Dct-Grm1/K5-Edn3) where metastasis to the lungs is 80% penetrant. The primary tumors of these mice present cellular heterogeneity with cells at varying levels of differentiation. The main goal of this study was to determine the metastatic potential of the primary tumor resident Tyrosinase positive cells and evaluate the dynamic phenotypic changes as those cells move from the primary tumors to the sites of metastasis. To accomplish this aim …

Phenomenological And Molecular Basis Of The Cnidarian Immune System, Tanya Brown

FIU Electronic Theses and Dissertations

Coral reefs are one of the most diverse ecosystems on the planet due partially to the habitat structure provided by corals. Corals are long lived organisms that can live for hundreds of years and as a result growth of many species is very slow. As a result of this, recovery of corals from disease outbreaks is very slow and difficult and therefore the ecosystem is deteriorating rapidly. Due to this increase in disease and its detrimental effect on coral reefs, it has become imperative to study how corals respond to disease outbreaks. The response of the coral to pathogens is …

Thermally-Assisted Acoustofluidic Separation For Bioanalytical Applications, Ata Dolatmoradi

FIU Electronic Theses and Dissertations

Changes in the biomechanical properties of cells accompanying the development of various pathological conditions have been increasingly reported as biomarkers for various diseases and as a predictor of disease progression stages. For instance, cancer cells have been found to be less stiff compared to their healthy counterparts due to the proteomic and lipidomic dysregulations conferred by the underlying pathology. The separation and selective recovery of cells or extracellular vesicles secreted from such cells that have undergone these changes have been suggested to be of diagnostic and prognostic value.

This dissertation first describes the implementation of a stiffness-based separation of phosphatidylcholine-based …

Laurel Wilt Disease: Early Detection Through Canine Olfaction And "Omics" Insights Into Disease Progression, Julian L. Mendel

FIU Electronic Theses and Dissertations

Laurel wilt disease is a vascular wilt affecting the xylem and water conductivity in trees belonging to the family Lauraceae. The disease was introduced by an invasive species of ambrosia beetle, Xyleborus glabratus. The beetle, together with its newly described fungal symbiont Raffaelea lauricola (pathogenic to host trees), has lead to the devastation and destruction of over 300 million wild redbay trees in southeastern forests. Ambrosia beetles make up a very unique clade of beetle and share a co-evolved obligatory mutualistic relationship with their partner fungi. Rather than consuming host tree material, the beetles excavate galleries or canals …

Transcriptomic And Epigenetic Responses To Environmental Stress In Marine Bivalves With A Focus On Harmful Algal Blooms, Maria Victoria Suarez Ulloa

FIU Electronic Theses and Dissertations

Global change poses new threats for life in the oceans forcing marine organisms to respond through molecular acclimatory and adaptive strategies. Although bivalve molluscs are particularly tolerant and resilient to environmental stress, they must now face the challenge of more frequent and severe Harmful Algal Blooms (HABs) episodes. These massive outbreaks of microalgae produce toxins that accumulate in the tissues of these filter-feeder organisms, causing changes in their gene expression profiles, which in turn modify their phenotype in order to maintain homeostasis. Such modifications in gene expression are modulated by epigenetic mechanisms elicited by specific environmental stimuli, laying the foundations …

A Floristic Study Of Halmahera, Indonesia Focusing On Palms (Arecaceae) And Their Seed Dispersal, Melissa E. Abdo

FIU Electronic Theses and Dissertations

The dispersal services of frugivores affect plant community assembly, persistence, and gene flow in the short-term, and in the long-term are critical to ensuring that tropical trees and palms can regenerate in disturbed areas and can migrate amidst climate change. Halmahera is the largest Moluccan island within the Wallacea biodiversity hotspot, yet data on its plant and animal distributions and interactions are almost null. I studied the tropical trees and palms of Halmahera and their seed dispersal dynamics. Chapter I explores the palms of the Moluccan islands through field-, herbarium-, and literature- based studies. The results of herbarium specimen collections …

Superoxide Dismutase C And Ras Affects Dictyostelium Contractile Vacuole Morphogenesis And Function, Adwait Kabra

FIU Electronic Theses and Dissertations

Dictyostelium cells lacking SodC displayed severely compromised CV morphogenesis and function. The sodC^- cells were vulnerable to hypotonic stress and showed poorly developed CV tubules, significant increase in the number of CV bladders, and a prolonged charging phase. Alleviation of the intracellular superoxide level in sodC^- cells with the cytoplasmic Superoxide dismutase A (SodA) or superoxide scavenger XTT significantly reduced the number of CV bladders to the level of the wild type, but the discharging step was still hampered. Introduction of redox insensitive RasG(C118A) mutant in sodC^- cells or inhibition of RasG target PI3K with LY204002 also …

Regulation Of Adipocyte Differentiation And Metabolism: Rab5-Guanine Nucleotide Exchange Factors And Methylglyoxal, Praew Chantarasinlapin

FIU Electronic Theses and Dissertations

Internalization and trafficking of ligand-receptor complex rely on a particular set of proteins, e.g. small GTPase protein Rab5 and its activators called guanine nucleotide exchange factors. Rab5-activating protein 6 (RAP6), a Vps9-containing protein, may participate in Rab5-mediated insulin signaling and receptor trafficking. A dicarbonyl compound methylglyoxal was found to alter insulin signaling in preadipocytes. This dissertation aimed to investigate the association of RAP6 activity on 3T3-L1 preadipocyte differentiation and those driven by methylglyoxal. Overexpression of RAP6 inhibited preadipocyte differentiation, Ser473-phosphorylation of Akt1, and expression of adipogenic marker PPARγ, but not C/EBPα. Methylglyoxal (10 µM) increased preadipocyte differentiation, proliferation and expression …

Reimagining Movements: Towards A Queer Ecology And Trans/Black Feminism, Gabriel Benavente

FIU Electronic Theses and Dissertations

This thesis seeks to bridge feminist and environmental justice movements through the literature of black women writers. These writers create an archive that contribute towards the liberation of queer, black, and transgender peoples.

In the novel Parable of the Talents, Octavia Butler constructs a world that highlights the pervasive effects of climate change. As climate change expedites poverty, Americans begin to blame others, such as queer people, for the destruction of their country. Butler depicts the dangers of fundamentalism as a response to climate change, highlighting an imperative for a movement that does not romanticize the environment as heteronormative, but …

Jewels For Dollars: Native And Nonnative Freshwater Fish Interactions In A Stressful Dry Down Environment, Vanessa Trujillo

FIU Electronic Theses and Dissertations

Vertebrate populations are subjected to novel anthropogenic stressors that are expected to multiply exponentially in the future. Introductions of nonnative species and human-altered hydrology are among these stressors to native species communities. The Rocky Glades, located in Everglades National Park, may serve as a population sink for native species that typically do not survive the altered hydrology of the dry season, and as a source of nonnative species that may be better adapted to chronically stressful conditions. In the seasonally-flooded Everglades, the nonnative African Jewelfish invaded in the 1960s and has since shown rapid range expansion. African Jewelfish are aggressive …

Green Sea Turtles (Chelonia Mydas) In Bermuda Exhibit An Ontogenetic Diet Shift Despite Overexploitation Of Resources In Their Developmental Habitat, Claire Margaret Burgett

FIU Electronic Theses and Dissertations

Green sea turtles in Bermuda are overgrazing the seagrasses on which later life stages are thought to specialize. I hypothesized that larger green turtles in Bermuda would display individual diet specializations during seagrass scarcity. Stable isotope methods were used to determine the diet composition of green sea turtles from the Bermuda Platform as a function of size class and in turtles captured in successive years. Individual turtles had a wide range of diets, however, the variation in diets was driven by differences among size class rather than within the size classes of larger turtles, indicating that green turtles undergo a …

Morphology, Architecture And Growth Of A Clonal Palm, Acoelorrhaphe Wrightii, Sara M. Edelman

FIU Electronic Theses and Dissertations

Palms provide valuable commercial resources in the tropics and are dominant species in tropical lowland forests. While general biology of palms is well studied, there are gaps in the literature on palm growth through life stages and in response to environmental conditions. Literature gaps on palm growth could be caused by the slow growth of palms; it is difficult to monitor morphology and architecture for the periods of time necessary to capture changes. Acoelorrhaphe wrightii is a threatened palm native to southern Florida with an unusual adult architecture. The purpose of this dissertation was to study growth A. wrightii throughout …

Experimental Analysis Of The Effects Of Hydroscape Structure On Fishes In A Dynamic Wetland, Michael R. Bush

FIU Electronic Theses and Dissertations

Hydroscape structure can play a critical role in animal behavior, abundance, and community structure dynamics. Hydroscape configuration can be dynamic and can change quickly in ephemeral systems. However, ephemeral freshwater wetlands are among the most impacted systems in the world and restoration efforts often rely on incomplete information when establishing management objectives. Further understanding how alterations in hydroscape structure in dynamic systems affect animals is critical for conservation and management success.

To determine impacts that changing hydroscape conditions can have on consumers in freshwater wetlands, I examined the effects of a large-scale physical model on fish behavior, abundance, and community …

Examining Movement And Habitat Selection Of Everglades Fishes In Response To Seasonal Water Levels, Gregory J. Hill

FIU Electronic Theses and Dissertations

Fish distribution patterns and seasonal habitat use play a key role in the food web dynamics of aquatic ecosystems, including the Florida Everglades. In this study I examined the fine scale habitat shifts and movements of spotted sunfish, Lepomis punctatus across varying seasons and hydrologic conditions using in-situ field enclosures and Passive Integrated Transponder (PIT) systems. Data on fish use of three dominant Everglades marsh habitats and activity level were recorded continuously from January to August, 2015. Fish were more active and had the highest use of higher elevation habitats when water levels rose during an experimental reversal in mid-April. …

Thermodynamics And Kinetics Of Ligand Photodissociation In Heme Proteins And Formation Of Dna I-Motif, David S. Butcher

FIU Electronic Theses and Dissertations

Heme proteins carry out a diverse array of functions in vivo while maintaining a well-conserved 3-over-3 α-helical structure. Human hemoglobin (Hb) is well-known for its oxygen transport function. Type 1 non-symbiotic hemoglobins (nsHb1) in plants and bacterial flavohemoglobins (fHb) from a variety of bacterial species have been predicted to carry out a nitric oxide dioxygenase function. In nsHb1 and fHb this function has been linked to protection from nitrosative stress. Herein, I combine photoacoustic calorimetry (PAC), transient absorption spectroscopy (TA), and classical molecular dynamics (cMD) simulations to characterize molecular mechanism of diatomic ligand interactions with a hexa-coordinate globin from plant …

Enzyme Catalyzed And Ultrasound Assisted Transformation Of Selected Pollutants, Yi Tan

FIU Electronic Theses and Dissertations

The widespread use of synthetic drugs and as feed additives has resulted in the release of large amounts of biologically active chemicals into the environment. Exposure to environmentally relevant concentrations of chemicals can have severe effects on human health. Therefore, effective degradation of these synthetic, biologically active compounds is of paramount importance.

Diphenhydramine (DPH) has been selected as a target compound for ultrasound remediation. The results demonstrated that ultrasound-induced degradation has potential applications in managing aqueous media contaminated with DPH.

Atorvastatin and roxarsone have been selected as representative substrates for chloroperoxidase (CPO) catalyzed transformation of pollutants. These studies demonstrate atorvastatin …