Life Sciences Commons^™

Design And Synthesis Of Novel Azasteroids And Pseudoazulenyl Nitrones, Nagaraju Birudukota

FIU Electronic Theses and Dissertations

Steroids are one of the essential classes of bioactive compounds and are involved in many biological functions which include their role as signaling compounds, the alteration of membrane fluidity and the regulation of a variety of metabolic processes. In order to identify novel compounds with beneficial pharmacological action, the synthesis of modified steroids is gaining much attention in recent years. Among those analogs, azasteroids are one of the most important classes which display a variety of biological activities, often free from undesirable side effects. The challenges in the synthesis of steroids, particularly azasteroids, and the potential of azasteroids as novel …

A Framework For Assessing Alternative Agro-Ecosystems: Finding Multi-Functional Solutions For Sustainable Urban Landscapes., Thais H. Thiesen Ms.

FIU Electronic Theses and Dissertations

Creating sustainable urban landscapes in light of growing population pressures requires interdisciplinary multi-functional solutions. Alternative agro-ecosystems described as food forests, permaculture gardens, and/or edible landscapes among others could offer potential ways to address the social, economic and ecological goals of various stakeholders simultaneously. The present research used a unique rubric, the Permaculture and Agro-ecosystems Sustainability Scorecard (PASS) that combines existing agricultural and landscape sustainability indicators in order to assess alternative agro-ecosystems. The rubric evaluates provisioning, regulating, supporting and cultural ecosystem services such as pollinator presence, biodiversity, pesticides and fertilizer use, carbon sequestration and human interactions. The PASS was used to …

Characterization Of Interaction Between Brevetoxin And Its Native Receptor And Identification Of The Role Of Brevetoxin In Karenia Brevis, Wei Chen

FIU Electronic Theses and Dissertations

Algae are important to marine and fresh-water ecosystems. However, some species of algae are harmful or even toxic. They can consume oxygen or block sunlight that is essential for other organisms to live. Indeed, some algae blooms can produce toxins that damage the health of the environment, plants, animals, and humans. Harmful algal blooms (HABs) which are often more green, brown, or dark-colored than red have spread along the coastlines and in the surface waters of the United States. Therefore, scientists are making great efforts to study HABs in order to maintain human and ecosystem health.

Karenia brevis, the …

Effects Of Catastrophic Seagrass Loss And Predation Risk On The Ecological Structure And Resilience Of A Model Seagrass Ecosystem, Robert J. Nowicki

FIU Electronic Theses and Dissertations

As climate change continues, climactic extremes are predicted to become more frequent and intense, in some cases resulting in dramatic changes to ecosystems. The effects of climate change on ecosystems will be mediated, in part, by biotic interactions in those ecosystems. However, there is still considerable uncertainty about where and how such biotic interactions will be important in the context of ecosystem disturbance and climactic extremes.

Here, I review the role of consumers in seagrass ecosystems and investigate the ecological impacts of an extreme climactic event (marine heat wave) and subsequent widespread seagrass die-off in Shark Bay, Western Australia. Specifically, …

An Ecological Study Of The Anurans In Tea Plantations In A Biodiversity Hotspot, Lilly M. Eluvathingal

FIU Electronic Theses and Dissertations

Increasing human population size is increasing the demand for resources like timber, oil, tea, coffee, and other crops. Plantation crops mimic some aspects of native habitats, and there are studies that report the presence of some native anuran biodiversity in plantations. I focused on tea plantations in the Western Ghats-Sri Lanka Biodiversity Hotspot and studied the diversity and health of anurans in different habitats found within a tea cultivation area, near Munnar region in the Western Ghats, India. The landscape includes tea bushes, native evergreen shola forest patches, and eucalyptus forest stands. I reviewed 40 studies comparing amphibian species richness …

Brain Networks Supporting Literacy Development, Iris J. Broce

FIU Electronic Theses and Dissertations

The development of fluent reading requires coordinated development of key fiber pathways. While several fiber pathways have been implicated in reading, including the recently re-identified vertical occipital fasciculus (VOF), inferior longitudinal fasciculus (ILF), arcuate fasciculus and its 3 components, and inferior fronto-occipital fasciculus (IFOF), whether these fiber pathways support reading in young children with little to no exposure to print remains poorly understood. Consequently, over the course of three studies, the current dissertation aimed to narrow this research gap by addressing the following research questions: 1) Which fiber pathways support early literacy skill in young children 5-10 years old? 2) …

Screening Of Plants For Antibacterial Properties: Growth Inhibition Of Staphylococcus Aureus By Artemisia Tridentata, Steven Ross Eichelbaum

FIU Electronic Theses and Dissertations

Drug-resistant pathogenic and opportunistic bacteria are increasing in occurrence and prevalence, and pose a dangerous threat to human health. In the search for novel antibiotics with which to combat this threat, plants, specifically those used in traditional medicine with ascribed antibacterial properties, offer a promising and potentially vast source of such therapeutic compounds. The purpose of this study was therefore to screen chemical extracts created from various plant species for antibacterial properties versus pathogenic bacterial species. In the course of these antibacterial assays, we successfully identified a methanol extract derived from Artemisia tridentata tridentata plant material as capable of inhibiting …

Targeted And Controlled Anticancer Drug Delivery And Release With Magnetoelectric Nanoparticles, Alexandra Rodzinski

FIU Electronic Theses and Dissertations

A major challenge of cancer treatment is successful discrimination of cancer cells from healthy cells. Nanotechnology offers multiple venues for efficient cancer targeting. Magnetoelectric nanoparticles (MENs) are a novel, multifaceted, physics-based cancer treatment platform that enables high specificity cancer targeting and externally controlled loaded drug release. The unique magnetoelectric coupling of MENs allows them to convert externally applied magnetic fields into intrinsic electric signals, which allows MENs to both be drawn magnetically towards the cancer site and to electrically interface with cancer cells. Once internalized, the MEN payload release can be externally triggered with a magnetic field. MENs uniquely allow …

The Optimization Of Pressure Cycling Technology (Pct) For Differential Extraction Of Sexual Assault Casework, Vanessa Martinez

FIU Electronic Theses and Dissertations

A two-step protocol has been devised as a rapid and selective alternative to conventional differential extraction techniques with an increased recovery of DNA. The protocol involves pressure cycling with the Barocycler^® NEP 2320 from Pressure Biosciences. Inc. in alkaline conditions for epithelial cell lysis and removal. This step is followed by alkaline lysis at 95^º C for extraction of sperm cell DNA. At 1:1 or 2:1 female to male cell ratios, high selectivity and complete separation can be achieved. But at higher ratios, male allelic dropout is observed. This protocol has been modified to generate a clean male …

Elucidating The Role Of Mifs-Mifr Two-Component System In Regulating Pseudomonas Aeruginosa Pathogenicity, Gorakh Digambar Tatke

FIU Electronic Theses and Dissertations

Pseudomonas aeruginosa is a Gram-negative, metabolically versatile, opportunistic pathogen that exhibits a multitude of virulence factors, and is extraordinarily resistant to a gamut of clinically significant antibiotics. This ability is in part mediated by two-component systems (TCS) that play a crucial role in regulating virulence mechanisms, metabolism and antibiotic resistance. Our sequence analysis of the P. aeruginosa PAO1 genome revealed the presence of two open reading frames, mifS and mifR, which encodes putative TCS proteins, a histidine sensor kinase MifS and a response regulator MifR, respectively. This two-gene operon was found immediately upstream of the poxAB operon, where poxB encodes …

Microbial Functional Diversity And The Associated Biogeochemical Interactions Across Miami-Dade County, Florida Soils, Priyanka Kushwaha

FIU Electronic Theses and Dissertations

Decomposition of soil organic matter by microbial processes results in carbon sequestration within soils and/or carbon loss via atmospheric emission of carbon dioxide and methane. Natural as well as anthropogenic factors have been documented to impact soil microbial diversity and the associated biogeochemical functions. The soil microbial communities co-inhabiting Miami-Dade County soils, Florida are under threat because of the ongoing restoration efforts in the adjoining Florida Everglades Parks, predicted climatic changes such as sea-level rise and high rainfall, as well as urbanization. Therefore, an improved understanding of the current microbial functional communities is essential to better assess the impact of …

Biogeographical Patterns Of Soil Microbial Communities: Ecological, Structural, And Functional Diversity And Their Application To Soil Provenance, Natalie Damaso

FIU Electronic Theses and Dissertations

The current ecological hypothesis states that the soil type (e.g., chemical and physical properties) determines which microbes occupy a particular soil and provides the foundation for soil provenance studies. As human profiles are used to determine a match between evidence from a crime scene and a suspect, a soil microbial profile can be used to determine a match between soil found on the suspect’s shoes or clothing to the soil at a crime scene. However, for a robust tool to be applied in forensic application, an understanding of the uncertainty associated with any comparisons and the parameters that can significantly …

A Morphological, Functional, And Genetic Investigation Of The Male Compound Eye Phenotype Of Chrysomya Megacephala (Diptera: Calliphoridae)), Joshua Smith

FIU Electronic Theses and Dissertations

A very unique compound eye in dipterans is found in males of the forensically important blow fly, Chrysomya megacephala (Diptera: Calliphoridae). This compound eye is characterized by an area of enlarged dorsal facets that, unlike almost all other regional changes in dipteran ommatidia size, is not accompanied by a change in resolution. This region is believed to play a role in mate tracking and allow for increased light capture, though no behavioral studies have tested these claims. An initial goal of the dissertation was to examine the function of this compound eye. Using allometric measurements coupled with behavioral tests, I …

Profiling Populations Using Neutral Markers, Major Histocompatibility Complex Genes And Volatile Organic Compounds As Modeled In Equus Caballus Linnaeus, Ketaki Deshpande

FIU Electronic Theses and Dissertations

Assessing the genetics of wild animal populations aims to understand selective pressures, and factors whether it be inbreeding or adaptation, that affect the genome. Although numerous techniques are available for assessing population structure, a major obstacle in studying wild populations is obtaining samples from the animals without having to capture them, which can lead to undue distress and injury. Therefore, biologists often use non-invasive sampling methods (i.e., collection of feces, hair) to extract host DNA. In this study, new DNA extraction protocols were developed that improved the quality and quantity of DNA obtained from fecal matter. Fecal samples aged up …

Trinucleotide Repeat Instability Is Modulated By Dna Base Lesions And Dna Base Excision Repair, Jill M. Beaver

FIU Electronic Theses and Dissertations

Trinucleotide repeat (TNR) expansions are the cause of over 40 human neurodegenerative diseases, and are linked to DNA damage and base excision repair (BER). We explored the role of DNA damage and BER in modulating TNR instability through analysis of DNA structures, BER protein activities, and reconstitution of repair using human BER proteins and synthesized DNA containing various types of damage. We show that DNA damage and BER can modulate TNR expansions by promoting removal of a TNR hairpin through coordinated activities of BER proteins and cofactors. We found that during repair in a TNR hairpin, coordination between the 5’-flap …

Investigating Sub-Tropical Community Resistance And Resilience To Climate Disturbance, Ross E. Boucek

FIU Electronic Theses and Dissertations

Changes in global climate will likely increase climate variability. In turn, changes in climate variability have begun to alter the frequency, intensity, and timing of climate disturbances. Continued changes in the climate disturbance regime experienced by natural systems will undoubtedly affect ecological processes at every hierarchical scale. Thus, in order to predict the dynamics of ecological systems in the future, we must develop a more mechanistic understanding of how and in what ways climate disturbance affects natural systems. In South Florida, two climate disturbances recently affected the region, a severe cold spell in 2010, and a drought in 2011. Importantly, …

Where Are All The Bonefish? Using Angler Perceptions To Estimate Trends Of Bonefish (Albula Vulpes) Decline In South Florida, Emily K.N. Kroloff

FIU Electronic Theses and Dissertations

Local ecological knowledge (LEK) is a useful method to capture environmental or resource changes when there is an absence of biological data. Since the bonefish fishery is data limited, this study aims to understand the trend of bonefish decline over the last 40 years using LEK and to assess whether varying fisher experience and fisher type would influence perception of bonefish decline. Semi-structured surveys and key informant interviews were conducted to collect LEK data. Along with perceiving an overall decline (p

Dna Aptamer Confirmation And Utilization For The Cyanotoxin, Cylindrospermopsin, Diane M. Catlin

FIU Electronic Theses and Dissertations

Cyanotoxins are posing an increasing threat to the health of humans and wildlife. Cylindrospermopsin is a cyanotoxin that occurs in warm climates and is harmful when ingested. The toxic effects of CYN can affect multiple organ systems. The effects, coupled with the evidence of a mass contamination of a water supply in Australia, prove that CYN needs to be investigated further.

Aptamers have become a desirable method for detection of CYN as a result of an aptamer’s high specificity and the ability to scale up experiments. Aptamers have been designed to bind with a variety of targets, including cyanotoxins. An …

Medicinal Plants Of Trinidad And Tobago: Selection Of Antidiabetic Remedies, Angelle L. Bullard-Roberts

FIU Electronic Theses and Dissertations

Diabetes mellitus (DM) is a group of non-infectious diseases that cause hyperglycemia. DM symptoms were first clinically described by ancient Greek physicians whose prescriptions included plant-based remedies. Today, DM affects >400 million people globally and prevalence rates are rapidly increasing in developing countries where basic healthcare relies on local knowledge of botanical remedies. Many developing countries are home to diverse peoples and plants—providing fodder for varied plant-selection strategies and unique botanical pharmacopoeias.

I addressed the plant-selection strategies used in a multi-ethnic, developing country, Trinidad and Tobago (T&T), to ascertain their role in shaping the local antidiabetic pharmacopoeia and to assess …

Community-Governed Multifunctional Landscapes And Forest Conservation In The Sierra Norte Of Oaxaca, Mexico, Barbara Pazos Almada

FIU Electronic Theses and Dissertations

Community forestry is an evolving approach to forest management, shown to maintain forest cover, while generating income for local communities. In Sierra Norte (SN), a region with no public protected areas, indigenous communities have been actively conserving their forests for decades, through conservation zoning and careful management of their logging areas. This study found that across 22 communities in SN, an estimated 2,949,116.50 m³ of timber were produced from 1993 to 2013, while the region maintains 78% forest cover. About 75% of the forest is under some form of community conservation. Community governance plays a major role, as rules …

Vocal Flexibility And Regional Variation In Free-Tailed Bat Song, Israel Salazar

FIU Electronic Theses and Dissertations

While much work has been done on regional vocal variation in birds, relatively few studies have found evidence of similar variation in mammalian vocalizations. This study quantifies individual, colonial, and regional level variation in T. brasiliensis songs in the southeastern United States. Brazilian free-tailed bats (Tadarida brasiliensis) are among a handful of mammals that produce complex, hierarchically structured vocalizations. Their songs are composed of multiple syllables that are combined into three phrases that vary in number and order across renditions. Tadarida brasiliensis songs showed considerable amount of variation, and differed significantly between locations in terms of syllable structure …

Effects Of Host-Plant Density On Herbivores And Their Parasitoids: A Field Experiment With A Native Perennial Legume, Andrea Salas

FIU Electronic Theses and Dissertations

Senna mexicana chapmanii (Fabaceae: Caesalpinoideae), an attractive and threatened species native to pine rocklands of southern Florida, is consumed by folivorous caterpillars of Sulfur butterflies (Lepidoptera: Pieridae). Caterpillars may be deterred or eaten by predators, but also very important are parasitoids, both flies and wasps. This study investigated the effects of plant density on Sulfur caterpillar numbers and rates of parasitization.

Senna mexicana chapmanii plantations were established at agricultural and urban areas; both sites are adjacent to protected pine rockland areas. Sulfur butterfly immature stages were collected and reared to glean information regarding number of herbivores and rates of parasitization. …

Pesticides And Pollination Of Imperiled Plants Of The Lower Florida Keys, Brittany M. Harris

FIU Electronic Theses and Dissertations

Degraded pollinator habitat may have far-reaching consequences for recovery of imperiled flowering plant populations. Studies indicate that broad-spectrum insecticides used in mosquito abatement are detrimental to non-target invertebrates, including pollinators. A decline in efficient pollinators can reduce plant fitness by decreasing reproductive output and constraining genetic diversity, a challenge for rare plants.

In 2015, I monitored flower visitation and fruit set of three imperiled plant species throughout protected areas on three islands in The Lower Florida Keys. These islands consist of conservation land fragmented by intermittently dispersed residential neighborhoods that seasonally spray insecticides for mosquito control. Flowers open at treatment …

Regulation Of Particle Uptake By Pp2a/B56 And Lkb1 In Dictyostelium Discoideum, Mujataba Rahiman Sharief

FIU Electronic Theses and Dissertations

Dictyostelium discoideum is a soil dwelling amoeba which has been widely used as a model organism to study cellular processes such as signal transduction, chemotaxis, endocytosis and exocytosis. The process of phagocytosis in Dicytostelium is largely comparable to that of neutrophils and macrophages in the mammalian system. Neutrophils and macrophages are cells of the innate immune system and they engulf infectious bacteria through phagocytosis. Dictyostelium cells uptake yeast and bacteria for their nutrition through phagocytosis, which is an actin dependent mechanism and is a target of multiple signaling inputs. Recent studies have uncovered different proteins involved in the signaling of …

Influence Of Experimental Sheet Flow On Aquatic Foods Webs Of The Central Everglades, Sarah C. Bornhoeft

FIU Electronic Theses and Dissertations

Establishing historical water velocities is a goal of Everglades restoration because of their role maintaining landscape topographic relief. However, flows may also change the trophic state of marshes by phosphorus loading. I used fatty acid (FA) and stoichiometric data to quantify how increased sheet flow altered the relative heterotrophic and autotrophic contributions to aquatic consumers in a field experiment that introduced flowing water to an Everglades marsh in November, 2014. Algal taxonomic composition was different between pre-flow and flow sampling, marked by increases in the nutrient exploiting Mougeotia species (green algae) during flow sampling. Dietary tracer FAs in consumers reflected …

The Degradation Of Pharmaceutical Pollutants In Wastewater Catalyzed By Chloroperoxidase And The Construction Of Chloroperoxidase H105r Mutant, Qinghao He

FIU Electronic Theses and Dissertations

Trace amounts of pharmaceuticals have been detected in water, from nanograms per liter to micrograms per liter, and have a negatively effect in the aquatic environment and an increased potential risk of drug poisoning for human and animals. In order to address the problem, drug degradation catalyzed by chloroperoxidase (CPO) has been investigated. CPO is a heme-containing glycoprotein secreted by the fungus, Caldariomyces fumago, it catalyzes two major types of oxidations, two one-electron oxidations as catalyzed by most peroxidases and two-electron oxidations which are rare for conventional peroxidases.

Five common drugs from a variety of classes which were persistent in …

Gammaridean Amphipods As Bioindicators In Subtropical Seagrass Ecosystems, Jennifer L. Sweatman

FIU Electronic Theses and Dissertations

Anthropogenic disturbances are ubiquitous in coastal marine ecosystems. As such, more intensive monitoring efforts are necessary to conserve these valuable habitats. Bioindicators, organisms that predictably respond to changes in environmental variables, may be utilized in monitoring efforts to assess ecosystem functioning. To incorporate organisms into monitoring programs as bioindicators managers need to first understand the difference between the natural phenology of the focal organisms and their responses to different forms of anthropogenic disturbance.

To determine if gammaridean amphipods could be used as indicators of changes in environmental quality in sub-tropical seagrass ecosystems, I conducted spatial and temporal surveys of amphipod …

Conformational Dynamics And Stability Associated With Magnesium Or Calcium Binding To Dream In The Regulation Of Interactions Between Dream And Dna Or Presenilins, Khoa Ngoc Pham

FIU Electronic Theses and Dissertations

Downstream regulatory element antagonist modulator (DREAM) is involved in various interactions with targets both inside and outside of the nucleus. In the cytoplasm, DREAM interacts with the C-terminal fragments of presenilins to facilitate the production of β-amyloid plaques in Alzheimer’s disease. In the nucleus, Ca²⁺ free DREAM directly binds to specific downstream regulatory elements of prodynorphin/c-fos gene to repress the gene transcription in pain modulation. These interactions are regulated by Ca²⁺ and/or Mg²⁺ association at the EF-hands in DREAM. Therefore, understanding the conformational dynamics and stability associated with Ca²⁺ and/or Mg²⁺ binding to DREAM …

Extraction, Purification And Partial Characterization Of A Carotenoid Binding Protein (Cbp) From The Epidermis Of The Monarch Butterfly Larvae (Danaus Plexippus), Nan Fang

FIU Electronic Theses and Dissertations

This dissertation describes the purification and partial characterization of CBP from the epidermis of the monarch butterfly larvae (Danaus plexippus). A yellow protein-carotenoid complex was extracted from the yellow pigmented epidermal tissue from monarch butterfly larvae by homogenization. Additional steps in the purification process included differential precipitation with ammonium sulfate, cation and anion chromatography, and lastly size exclusion chromatography. Polyacrylamide gel electrophoresis demonstrates that a single protein was isolated (M-LBP) having a ~60 kDa molecular weight, the value has subsequently been confirmed by HR-tandem MS. Lutein is the sole carotenoid bound by M-LBP with a stoichiometry of the …

Comparison Of Synthetic Versus Organic Herbicides/Insecticides On Arbuscular Mycorrhizal Fungi In Abelmoschus Esculentus, Ariel Freidenreich

FIU Electronic Theses and Dissertations

Arbuscular mycorrhizal fungi (AMF) play a crucial role in improving the growth of a vast majority of plants. Past researchers have discovered that agricultural practices have a significant negative effect on the diversity of AMF. Arbuscular mycorrhizal fungi are reported to enhance plant nutrient uptake, stress tolerance, and soil aggregate formation which are key aspects of productive low-input farming. The objective of this study was to investigate the effects of four pesticides on the ability of AMF to colonize the roots of okra plants (Abelmoschus esculentus). The pesticides being tested include two synthetic chemicals (glyphosate and carbaryl) and …