Life Sciences Commons^™

Taking Apart The Time Machine: Investigating Space-For-Time Substitution Modeling In The Florida Everglades, Theresa Kelly Brown

FIU Electronic Theses and Dissertations

Space-for-Time substitution modeling has been used with increasing frequency to identify functional relationships between environmental drivers and ecological responses. I investigated the use of space-for-time substitution as a null model and beta diversity as a validity test for this null model in the Greater Everglades aquatic metacommunity. I began by conducting a literature review and analysis to investigate the suitability of the space-for-time substitution method as a null model. I then analyzed beta diversity of the Greater Everglades aquatic metacommunity through a sums-of-squares approach. Finally, I tested for correlation between the beta diversity analysis and the space-for-time models. Results indicate …

Characterizing Elasmobranch Species Diversity, Occurrence And Catches In Small-Scale Fisheries Of The Caribbean, Camila Cáceres

FIU Electronic Theses and Dissertations

Although 95% of fishers are artisanal, little is known about the magnitude of their catches and impacts on marine ecosystems at a global scale. I used a rapid assessment framework to study elasmobranch occurrence, elasmobranch fisheries, and use in coastal small-scale fisheries in the Caribbean, combining observational data and fisher’s knowledge. A total of 800 Baited Remote Underwater Videos were deployed in addition to 660 interview surveys that were collected in Colombia, Guadeloupe, Martinique, Tobago and the Florida Keys. In Colombia, I compared elasmobranch and teleost species richness and relative abundance within four coral reef habitats, where species targeted by …

Structural Basis For Chloroperoxidase Catalyzed Enantioselective Epoxidations And Mechanisms Of Selected Anticancer Drug Induced Apoptosis, Yongjian Guo

FIU Electronic Theses and Dissertations

Chloroperoxidase (CPO), a member of the heme peroxidase family, has diverse catalytic activities toward a broad range of substrates. In addition to catalyzing halogenation reactions involved in the biosynthesis of halogen-containing compounds, CPO also catalyzes reactions typical of traditional heme peroxidases, catalases, and cytochrome P450 enzymes. Despite the powerful and versatile catalytic activity of CPO, its applications have been thwarted by the difficulty in regenerating the active enzyme and substrate (peroxide) induced protein inactivation. To overcome these shorting comings of the protein, we investigate the fabrication and characterization of chloroperoxidase (CPO) and glucose oxidase (GOx) on the surface of MGO. …

Dual Role Of Rin1 In Cancer Cell Behavior: Is Cortactin A New Rin1-Interacting Partner?, Wei Zhang

FIU Electronic Theses and Dissertations

Growth factors play an essential role in abnormalities in both intracellular trafficking and signal transduction pathways responsible in normal and cancer cells. Growth factors, such as epidermal growth factor, represent a main course on the activation of mitogenic signal that contribute to the mitogen activated protein kinase (MAPK) pathway affecting cell proliferation, which is driven by Ras GTPases. However, it also induces a profound morphological change by reorganization actin and other cytoskeleton proteins, which are driven by other GTPases (i.e., Rho and Rac). Ras interference 1 (Rin1) is a key cytosolic protein, that regulates both membrane trafficking and signaling pathways …

Influence Of Vermicompost Tea On Secondary Metabolites In Solanum Lycopersicum Within South Florida, Daphne K. Sugino Souffront

FIU Electronic Theses and Dissertations

Fresh Market Tomatoes provide a high revenue stream for Florida’s agricultural sector. To attain profitable yields, farmers introduce high inputs of pesticides to suppress pest invasion/damage. Heavy usage of pesticides has adverse effects on human and environmental health. A possible solution might be the incorporation of vermicompost in pest management. Typically used as a fertilizer, vermicompost has pest suppressant properties. Mechanisms influencing enhanced pest resistance are unknown. To identify such mechanisms, a study was conducted to evaluate physical and chemical changes of the BHN589 tomato plant following the addition of varying vermicompost tea treatments (T5%, T10%, and T20%) . Results …

The Role Of Inositol Polyphosphate-4-Phosphatase Type Ii B (Inpp4b) In Obese Models And Endocrine Cancers, Manqi Zhang

FIU Electronic Theses and Dissertations

INPP4B is a dual-specificity phosphatase and a tumor suppressor in prostate and breast cancers. Progression of the prostate and breast cancers depends on the androgen receptor (AR) or estrogen receptor alpha (ERα) signaling, respectively. In this work we demonstrated that INPP4B reprograms ERα transcriptional activity in breast cancer. INPP4B maintains expression and protein levels of progesterone receptor (PR), an ERα direct target gene required for mammary gland development. Consistently we demonstrated that Inpp4b knockout severely impairs lateral branching in the mammary gland of maturing virgin females. In advanced prostate cancer, activation and transcriptional reprogramming of AR frequently coincides with the …

Evolutionary Genetics Of The Genus Zamia (Zamiaceae, Cycadales), Michael Calonje

FIU Electronic Theses and Dissertations

The genus Zamia L. (Zamiaceae), consisting of 77 species, is the most species-rich and widely distributed cycad genus in the New World and is arguably the most morphologically and ecologically diverse genus in the Cycadales. We utilized a multilocus sequence dataset of 10 independent loci (9 single copy nuclear genes + 1 plastid) and extensive taxon sampling (over 90% of species) to infer phylogenetic relationships within Zamia. We infer a robust phylogenetic tree for the genus with a strong geographic delimitation of clades and find that four morphological characters typically used for diagnostic purposes in the genus exhibit a high …

Regulation Of Telomerase Activity By Rab5 Guanine Nucleotide Exchange Factors, Patric J. Hambleton

FIU Electronic Theses and Dissertations

Many cancerous cells display abnormalities in the signal transduction pathways responsible for responding to extracellular growth factors. Growth factors, such as insulin-like growth factor I, represent a major class of mitogenic ligands that can initiate the mitogen activated protein kinase (MAPK) pathway. The role of the MAPK pathway in transducing growth signals to the interior of the cell and subsequently stimulating cell growth and proliferation is highlighted by the fact that roughly one quarter of all human tumors contain mutant forms of Ras proteins. Ras interference 1 (Rin1) is involved in key steps of receptor mediated endocytosis and can potentially …

Incorporating Early Life History And Recruitment In Analysis Of Population Dynamics Of Wetland Fishes, John Vincent Gatto

FIU Electronic Theses and Dissertations

Hydrological variation is believed to be the major abiotic factor influencing fish recruitment in floodplain ecosystems. However, past studies fail to address the impact of hydrology on the three major drivers of recruitment: age-specific growth and mortality, and dispersal. I examined long-term recruitment dynamics for six fish species inhabiting the Everglades by addressing the impact of hydrology on these important characteristics. I then linked these changes to annual fluctuations in population size.

Before interpreting time-series data on recruitment, I evaluated the impact of size-selective bias from sampling gear on our interpretation of hydrological drivers of recruitment. Analyses revealed that individuals …

The Genetics Of Olfactory And Visually Guided Attractive Behaviors In Aedes Aegypti Mosquito, Joshua Ibukun Raji

FIU Electronic Theses and Dissertations

Mosquitoes detect their hosts and seek suitable resources crucial for survival by integrating chemosensory, thermal, and visual cues. The diversity of the cues involved in mosquito attractive behaviors has made the design of behavioral control strategies a challenge. The genetic basis of mosquito attractive behaviors can now be determined using genome editing. The contribution of the IR8a chemosensory pathway was uncovered by disrupting the IR8a co- receptor in Aedes aegypti using CRISPR/Cas9. Ir8a mutant female mosquitoes are not attracted to lactic acid, a behaviorally active component of human sweat, and lack odor-evoked responses to acidic volatiles. The loss of Ir8a …

Mechanisms For The Persistence Of The Coral Holobiont In The Warming Oceans Of The Anthropocene, Daniel G. Merselis

FIU Electronic Theses and Dissertations

Coral Reefs are rapidly deteriorating in response to an onslaught of human-mediated stressors. Just one stressor alone, climate change, may extirpate coral reef ecosystems within a human lifetime, threatening societal and ecological catastrophe. Reef-derived ecosystem services are crucial for sustenance, coastal protection, and economic prosperity in over 100 countries. Near-term human decisions will determine whether reef-corals, the ecosystems they engineer, the 25% of marine biodiversity they support, and the human communities that depend upon them can be protected. My dissertation aims to characterize the potential for corals' adaptive mechanisms to facilitate their continued survival- information which will only represent hope …

Exploring The Potential Of Endophytes And Medicinal Plants As Sources Of Antimicrobials To Control Citrus Greening, Jessica Dominguez

FIU Electronic Theses and Dissertations

Citrus greening is an economically disastrous bacterial disease that infects all species of citrus, and currently has no cure. It is caused by Candidatus Liberibacter asiaticus (CLas), an unculturable phloem-limited bacteria vectored by the sap-sucking insect Diaphorina citri. Citrus greening has spread to every citrus-producing county in Florida; thus, there is a crucial need to develop environmentally safe treatments to reduce or eliminate CLas. It was hypothesized that endophytic microorganisms isolated from survivor citrus trees would show antagonistic activity against CLas; also, that plant extracts with known antimicrobial properties could suppress CLas. Oregano, thyme and turmeric extracts in the …

Functionalized Aptamers For Detection Of Small-Molecule Targets, Haixiang Yu

FIU Electronic Theses and Dissertations

Aptamers have recently gained considerable attention for small-molecule detection in diverse applications such as drug identification, medical diagnostics, and environmental monitoring. However, the performance of aptamer-based sensors has been greatly limited by the low target affinity and responsiveness of small-molecule binding aptamers. This dissertation describes several novel aptamer engineering and isolation strategies to remedy this problem. Specifically, we first develop a generally applicable strategy to engineer split aptamers containing two binding domains termed cooperative-binding split aptamers (CBSAs). CBSAs exhibit higher target binding affinity and are far more responsive in terms of target-induced split aptamer assembly compared to single-domain parent split …

Assessment Of Watersheds For Sustainable Agriculture In Karnataka, India, Nicholas Adam Charles

FIU Electronic Theses and Dissertations

Modernization of traditional small-scale irrigation tanks in India is becoming increasingly popular. This is due to high costs of the alternative, of developing and constructing large-scale projects in rural areas. Examination of management strategies, resource allocation, and collective action has become paramount for promoting food security and livelihoods in water-stressed areas of Southeast Asia. Geographic Information System (GIS) and Remote Sensing techniques are valuable to assessing the management of these irrigation systems, specifically small water storage reservoirs that capture runoff from the monsoon known as irrigation tanks. The primary goal of this study is to develop a stakeholder-informed approach to …

Effects Of Phosphorus On Benthic Diatom Assemblage Network Structure, Eric M. Massa

FIU Electronic Theses and Dissertations

Ecological network analysis helps identify how relationships among species differ over time and across sets of species. Microbial assemblages are ideal for evaluating changes in species interactions due to environmental changes because they are speciose and respond at multiple scales. To determine how phosphorus limitation influences diatom network structure, I analyzed relationships among 257 species of diatoms from benthic microbial (periphyton) mats from 10 years of annual samples from 136 sites. Expected evidence of changes in network structure in response to periphyton TP were not found, likely due to species replacement with increased TP. Analysis of species connection distributions and …

Inoculating Rhizobium And Arbuscular Mycorrhizal Fungi On Snap Bean Under Salinity Stress To Study Plant Growth And Glomalin Production Effects, Claudia Lyl Garcia

FIU Electronic Theses and Dissertations

Groundwater salinization from saltwater intrusion threatens Southeastern Florida’s commercially important snap bean (Phaseolus vulgaris) production because of the crop’s low salt-tolerance threshold. The present study was carried out to determine if co-inoculating salt-stressed snap beans with beneficial microbial symbionts (i.e., Rhizobium and arbuscular mycorrhizal fungi) can mitigate growth reductions. Additionally, the study also assessed whether co-inoculation had an effect on the production of glomalin, a protein secreted by arbuscular mycorrhizal fungi that improves soil aggregation. Snap beans were inoculated (-AMF/-Rhizobium, +AMF/-Rhizobium, +AMF/+Rhizobium) and irrigated with varying salinity levels (0.6, 1.0, 2.0 dS …

Topoisomerase And Tyrosyl-Dna-Phosphodiesterase Ratio As An Indicator For The Response Of Glioblastoma Cancer To Topoisomerase Targeting Anticancer Drugs, Wenjie Wang

FIU Electronic Theses and Dissertations

Glioblastoma (GBM) patients have an estimated survival of ~15 months, with the standard of care (surgery, radiation, and chemotherapy) that has only modestly enhanced patient survival. Identifying biomarkers representing vulnerabilities in GBM biology may allow for the selection of effective and safe chemotherapy options. Irinotecan (IRT), a genotoxic compound currently in clinical trials for GBM, targets topoisomerase I (TOP1) by forming an irreversible ternary DNA-TOP1 cleavage complex (TOP1cc) and leads to apoptosis. Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a crucial repair enzyme that rescues TOP1cc and reduces the effectiveness of IRT. In the current study, we evaluate the value of the …

Cavity Nest Webs As A Template For Studying Non-Trophic Interactions In Invasion Ecology, Joshua M. Diamond

FIU Electronic Theses and Dissertations

Invasive exotic animals are considered destructive forces in cities for preying on and competing with native species. I examined an aspect of competition from a different perspective, focusing on the role of Miami’s rich exotic bird assemblage in its cavity nest web, where a supply of woodpecker-created cavity nests limited by urbanization is the focal point of competition. We located 967 nest trees with 1,864 cavities and determined that woodpeckers successfully nested in this tropical urban region by exploiting standing dead palms (snags). Native upland forests were the most important cover type for woodpeckers but planted landscapes like parks and …

Evolutionary Expansions And Neofunctionalization Of Ionotropic Glutamate Receptors In Cnidaria, Ellen G. Dow

FIU Electronic Theses and Dissertations

Reef ecosystems are composed of a variety of organisms, transient species of fish and invertebrates, microscopic bacteria and viruses, and structural organisms that build the living foundation, coral. Sessile cnidarians, corals and anemones, interpret dynamic environments of organisms and abiotic factors through a molecular interface. Recognition of foreign molecules occurs through innate immunity via receptors identifying conserved molecular patterns. Similarly, chemosensory receptors monitor the environment through specific ligands. Chemosensory receptors include ionotropic glutamate receptors (iGluRs), transmembrane ion channels involved in chemical sensing and neural signal transduction. Recently, an iGluR homolog was implicated in cnidarian immunological resistance to recurrent infections of …

Molecular Mechanism(S) Of Zika Virus Infection And Associated Neuropathogenesis, Chet Raj Ojha

FIU Electronic Theses and Dissertations

Zika virus (ZIKV), a mosquito-borne flavivirus, is known to induce various neurodevelopmental disorders including microcephaly and growth retardation in newborns from infected mothers. However, the exact mechanism of ZIKV-associated neurodevelopmental disorders is still unknown. The study was aimed at identifying the molecular mechanism(s) of ZIKV infection using in-vitro and in vivo methods. Using three isolated strains of ZIKV (MR766, R103451, and PRVABC59), we show that the Asian strains of ZIKV are more infective and toxic to glial cells and neurons compared to the African strain. Infection by PRVABC59 induces markedly higher release of inflammatory molecules; IP10, RANTES, IL-6, and IFN-β. …

The Relationship Of A Novel Marker Of Inflammation (Neutrophil-To-Lymphocyte Ratio) To Nutritional Status, Diet And Clinical Outcomes In Hemodialysis Patients, Janet Diaz Martinez

FIU Electronic Theses and Dissertations

The aim of this dissertation was to examine prospectively the relationship of a novel marker of inflammation (neutrophil-to-lymphocyte ratio) with nutrition markers, diet and clinical outcomes in a cohort study that included 77 patients from one hemodialysis (HD) center located in South Florida. Demographics and clinical parameters were obtained from patients’ medical charts. Nutritional status was determined at baseline, six and 12 months using the Malnutrition-Inflammation Score (MIS) and the 7-point Subjective Global Assessment (SGA) scale consisting of two categories: medical history and physical examination. Dietary assessments were performed, and 24-hour diet recalls were collected at each assessment visit. Neutrophil-to-Lymphocyte …

Developing A Meta-Population Framework For Caribbean Spiny Lobster (Panulirus Argus) Stocks, Nan Yao

FIU Electronic Theses and Dissertations

The Caribbean spiny lobster (Panulirus argus) provides many ecological and economic benefits to the Southeast United States, as well as many South American and Caribbean countries. However, limited knowledge on the recruitment dynamics of this valuable species has long been an issue for the fishery management. Panulirus argus has a pelagic larval stage called the phyllosoma. During the larval stage, a phyllosoma can drift with currents from six to nine months. This long pelagic life stage leads to the hypothesis that P. argus stocks in the Caribbean are demographically open. Evidences from biophysical modeling and genetic analysis have …

Computational Analysis Of Large-Scale Trends And Dynamics In Eukaryotic Protein Family Evolution, Joseph Boehm Ahrens

FIU Electronic Theses and Dissertations

The myriad protein-coding genes found in present-day eukaryotes arose from a combination of speciation and gene duplication events, spanning more than one billion years of evolution. Notably, as these proteins evolved, the individual residues at each site in their amino acid sequences were replaced at markedly different rates. The relationship between protein structure, protein function, and site-specific rates of amino acid replacement is a topic of ongoing research. Additionally, there is much interest in the different evolutionary constraints imposed on sequences related by speciation (orthologs) versus sequences related by gene duplication (paralogs). A principal aim of this dissertation is to …

The Immunosuppressive Role Of Edn3/Ednrb Signaling In The Melanoma Microenvironment, Juliano Tiburcio De Freitas

FIU Electronic Theses and Dissertations

Endothelins are cytokines ubiquitously expressed in the microenvironment of several tumors. In melanoma is not clear whether stromal cells respond to the endothelin present in the microenvironment. To address this question, I generated tumors derived from different murine melanoma cell lines (B16F10, YUMM1.7, YUMMER1.7) in a transgenic mouse that overexpresses endothelin 3 (Edn3) by keratinocytes in the skin (K5-Edn3). Tumors from all the cell lines grew larger and were more aggressive when Edn3 was overexpressed in the skin. In tumors derived from YUMM1.7-GFP cells, very few tumorigenic cells expressed the Edn3 receptor, Endothelin receptor b (Ednrb) suggesting an …

Role Of Withaferin A As A Neuroprotectant Against Beta Amyloid Induced Toxicity And Associated Mechanism, Sneham Tiwari

FIU Electronic Theses and Dissertations

Neurological disorders are the biggest concern globally and ageing contributes in worsening the disease scenarios. In AD or AD like diseases, there is abnormal accumulation of extracellular amyloid beta produced due to abnormal processing of the transmembrane amyloid precursor protein, by β and γ-secretases. It spreads in the cortical and limbic regions of the brain leading to neuronal toxicity, impairment in memory and neurological functions. Aβ deposition in the CNS is common in aging HIV patients. Neurotoxic protein Tat, results in increased Aβ in combination with drugs of abuse cocaine. We examined the role of Withaferin A, against Aβ induced …

The Effect Of Proteome And Lipidome On The Behavior Of Membrane Bound Systems In Thermally-Assisted Acoustophoresis, Elnaz Mirtaheri

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, including cancers. In cancer cells, the membrane properties have been altered compared to their healthy counterparts primarily due to proteomic and lipidomic dysregulations conferred by the underlying pathology. The separation and selective recovery of these cells or extracellular vesicles secreted from such cells is of high diagnostic and prognostic value.

In this dissertation, the research builds on thermally-assisted acoustophoresis technique which was developed in our laboratory for the separation of vesicles of the same size, charge and …