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Title: Phenotypic and behavioral effects of methionine sulfoxide reductase deficiency and oxidative stress in Drosophila melanogaster.
Creator: Mulholland, Kori., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Harman's theory of aging proposes that a buildup of damaging reactive oxygen species (ROS) is one of the primary causes of the deleterious symptoms attributed to aging. Cellular defenses in the form of antioxidants have evolved to combat ROS and reverse damage; one such group is the methionine sulfoxide reductases (Msr), which function to reduce oxidized methionine. MsrA reduces the S enantiomer of methionine sulfoxide, Met-S-(o), while MsrB reduces the R enantiomer, Met-R-(o). The focus of...
Show moreHarman's theory of aging proposes that a buildup of damaging reactive oxygen species (ROS) is one of the primary causes of the deleterious symptoms attributed to aging. Cellular defenses in the form of antioxidants have evolved to combat ROS and reverse damage; one such group is the methionine sulfoxide reductases (Msr), which function to reduce oxidized methionine. MsrA reduces the S enantiomer of methionine sulfoxide, Met-S-(o), while MsrB reduces the R enantiomer, Met-R-(o). The focus of this study was to investigate how the absence of one or both forms of Msr affects locomotion in Drosophila using both traditional genetic mutants and more recently developed RNA interference (RNAi) strains. Results indicate that lack of MsrA does not affect locomotion. However, lack of MsrB drastically reduces rates of locomotion in all age classes. Furthermore, creation of an RNAi line capable of knocking down both MsrA and MsrB in progeny was completed.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3362558
Subject Headings: Drosophila melanogaster, Genetics, Aging, Molecular aspects, Oxidative stress, Mitochondrial pathology, Cellular signal transduction, Oxidation-reduction reaction, Biochemical markers, Mutation (Biology)
Format: Document (PDF)

Title: New insights into the neuromodulatory role and potential action site of taurine in retinal neurons.
Creator: Bulley, Simon, Charles E. Schmidt College of Science, Department of Biomedical Science
Abstract/Description: Taurine is the second most abundant amino acid in the CNS after glutamate and its functions have been found largely related to intracellular calcium ([Ca2+]i) modulation, osmoregulation, membrane stabilization, reproduction and immunity. The action of taurine has also been implicated in neurotransmission and neuromodulation though its specific sites of action are not fully understood. Isolated retinal neurons from the larval tiger salamanders (Ambystoma tigrinum) were used as a model to study...
Show moreTaurine is the second most abundant amino acid in the CNS after glutamate and its functions have been found largely related to intracellular calcium ([Ca2+]i) modulation, osmoregulation, membrane stabilization, reproduction and immunity. The action of taurine has also been implicated in neurotransmission and neuromodulation though its specific sites of action are not fully understood. Isolated retinal neurons from the larval tiger salamanders (Ambystoma tigrinum) were used as a model to study the neuromodulatory role of taurine in the CNS and to gain insights into its potential sites of action. A combination of techniques was used, including whole-cell patch clamp recording to study taurine's regulation of voltage-gated potassium (K+) and Ca2+ channels and Fluo-4AM Ca2+-imaging to study taurine's regulation of glutamate-induced [Ca2+] I,. Taurine was shown to suppress of glutamate-induced [Ca2+] l, in a dose dependent manner. This suppression was mostly sensitive to the glycine rece ptor antagonist Strychnine but insensitive to any GABA receptor antagonist. The remaining strychnine-insensitive effect was inhibited with the protein kinase A (PKA) inhibitor, PKI, suggesting that there was an additional metabotropic pathway. Moreover, using the protein kinase C (PKC) inhibitor, GF109203X, there was an enhancement in strychnine-insensitive taurine's regulation. Taurine inhibits voltage-gated Ca2+ channels in the retinal neurons and has a dual effect on voltage-gated K+ channels. Taurine causes an increase in K+ current amplitude which is further enhanced with PKI and blocked with GF109203X, suggesting that it is through a PKC-dependent pathway negatively controlled by PKA-dependent pathway., There is a suppression of K+ current by taurine with intracellular application of GF109203X, suggesting that the reduction is through a PKA-dependent pathway. With both PKC and PKA inhibitors there is no longer an enhancement in maximum amplitude but a shift of volt dependence on a hyperpolarizing direction. Taurine's enhancement of K+ current is blocked by the Kv1.3 subtype antagonist Margatoxin, with Kv1.3 accounting for the majority of delayed-rectifier sustained current in bipolar and amacrine cells, as well as 50% of ganglion cells. Interestingly, the enhancement of K+ current by taurine is blocked by 5HT2A antagonist MDL11939, suggesting that activation of PKC is through this metabotropic serotonin receptor subtype. The suppression of voltage-gated Ca2+ channels is reversed with a combination of MDL11939 and the 5HT1A antagonist NAN-190. These results provide the evidence that the natural effect of taurine in the retinal neurons might be dependent on the activation of both 5HT1A and 5HT2A receptors. The high apparent activity of taurine on 5HT receptors could have important implication for the actions of taurine in central brain in which taurine has been known to be beneficial for improving mental health, as well as learning and memory processes.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2953206
Subject Headings: Biological transport, Eye, Physiology, Taurine, Physiological effect, Taurine, Therapeutic use, Central nervous system, Physiology
Format: Document (PDF)

Title: Potential therapies and neuroprotective cascades in anoxia tolerant freshwater turtle Trachemys scripta ellegans.
Creator: Nayak, Gauri., Charles E. Schmidt College of Science, Department of Biomedical Science
Abstract/Description: Mammalian neurons exhibit extreme sensitivity to oxygen deprivation and undergo rapid and irreversible degeneration when oxygen supply is curtailed. Though several neuroprotective pathways are activated during oxygen deprivation, their analyses are masked by the complex series of pathological events which are triggered simultaneously. Such events can be analyzed in the anoxia tolerant fresh water turtle, which can inherently survive the conditions of oxygen deprivation and post-anoxic...
Show moreMammalian neurons exhibit extreme sensitivity to oxygen deprivation and undergo rapid and irreversible degeneration when oxygen supply is curtailed. Though several neuroprotective pathways are activated during oxygen deprivation, their analyses are masked by the complex series of pathological events which are triggered simultaneously. Such events can be analyzed in the anoxia tolerant fresh water turtle, which can inherently survive the conditions of oxygen deprivation and post-anoxic reoxygenation without brain damage. It is likely in such a model that modulation of a particular molecular pathway is adaptive rather than pathological. The major objective behind this study was to analyze the intracellular signaling pathways mediating the protective effects of adenosine, a potential neuromodulator, and its effect on cell survival by influencing the key prosurvival proteins that prevent apoptosis. In vivo and in vitro studies have shown that adenosine acts as a neuroprotective metabolite and its action can be duplicated or abrogated using specific agonist and antagonists. Stimulating the adenosine receptors using selective A1 receptor agonist N6-cyclopentyladenosine (CPA) activated the presumed prosurvival ERK and P13-K/AKT cascade promoting cell survival, and suppression of the receptor using the selective antagonist DPCPX (8- cyclopentyl-1,3-dipropylxanthine) activated the prodeath JNK and P38 pathways. The complex regulation of the MAPK's/AKT signaling cascades was also analyzed using their specific inhibitors. The inhibiton of the ERK and AKT pathway increased cell death, indicating a prosurvival role, whereas inhibiton of the JNK and p38 pathway increased cell survival in this model. In vitro studies have also shown a high Bcl-2/BAX ratio during anoxia and reoxygenation, indicating a strong resistance to cell death via apoptosis., Silencing of the anti-apoptotic Bcl-2 gene using specific siRNA upregulated levels of prodeath BAX, thus altering the Bcl-2/BAX ratio and elevating cleaved Caspase-3 levels leading to increased cell death. Another promising neuroprotective target which we analyzed was Neuroglobin, which was induced during oxygen crisis and silencing this gene indicated that its plays a major role in modulation of ROS. This study strongly emphasizes the advantages of an alternate animal model in elucidating neuroprotective mechanisms and revealing novel therapeutic targets which could eventually help clinicians to design new stroke therapies based on naturally tolerant organisms.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/186762
Subject Headings: Turtles, Physiology, Adenosine, Receptors, Cellular signal transduction, Molecular neurobiology, Apoptosis, Research, Cellular control mechanisms
Format: Document (PDF)

Title: Thermodynamics-structure correlations of interactions between metalloproteinases and tissue inhibitors of metalloproteinase variants.
Creator: Wu, Ying., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The 23 matrix metalloproteinases (MMPs) in humans catalyze the turnover of all protein components of the extracellular matrix (ECM) and have important roles in tissue remodeling, wound healing, embryo implantation, cell migration and shedding of cell surface proteins. Excess MMP activities are associated with many diseases including arthritis, heart disease and cancer. The activities of MMPs are regulated by a family of four protein inhibitors, the tissue inhibitors of metalloproteinases ...
Show moreThe 23 matrix metalloproteinases (MMPs) in humans catalyze the turnover of all protein components of the extracellular matrix (ECM) and have important roles in tissue remodeling, wound healing, embryo implantation, cell migration and shedding of cell surface proteins. Excess MMP activities are associated with many diseases including arthritis, heart disease and cancer. The activities of MMPs are regulated by a family of four protein inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), that are endogenous inhibitors of matrix metalloproteinases (MMPs), ADAMs (A Disintegrin And Metalloproteinase) and ADAMTS (disintegrin-metalloproteinase with thrombospmdin motifs) .... The balance between TIMPs and active metzinicins is very important and imbalances are linked to human diseases such as arthritis, cancer, and atherosclerosis. The engineering of TIMPs to produce specific inhibitors of individual MPs could provide new therapeutic principles for disease treatment, but this requires a detailed understanding of the biophysical and structural basis of the interactions of TIMPs and MMPs and ADAMs.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3356904
Subject Headings: Proteolytic enzymes, Metalloproteinase, Inhibitors, Apoptosis, Extracellular matrix proteins
Format: Document (PDF)

Title: The ascidian Styela plicata as a potential bioremediator of bacterial and algal contamination of marine estuarine waters.
Creator: Draughon, Lisa D., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The tunicate Styela plicata (Ascidiacea) was investigated for its potential use in bioremediation of bacteria and microalgae blooms from estuarine waters. Salinity tolerances, filtration rate, substrate selection, and effects on digested bacteria and ichthyofaunal communities were examined. If acclimated slowly, Styela can be placed in salinities as low as 24 parts per thousand (ppt) before increased fatalities result. An immediate decrease in salinity from 32 ppt to 20 ppt was not...
Show moreThe tunicate Styela plicata (Ascidiacea) was investigated for its potential use in bioremediation of bacteria and microalgae blooms from estuarine waters. Salinity tolerances, filtration rate, substrate selection, and effects on digested bacteria and ichthyofaunal communities were examined. If acclimated slowly, Styela can be placed in salinities as low as 24 parts per thousand (ppt) before increased fatalities result. An immediate decrease in salinity from 32 ppt to 20 ppt was not detrimental at short term exposure (four days). One average-sized (~40g) Styela, exposed to 105 and 106 bacteria or microalgae mL-1, can filter as much as 4.7 L hr-1 and 3.3 L hr-1, respectively. Individual tunicate filtration rates varied from hour to hour, independent of organism size, indicating that filtration rates for this species would be better reported on a population basis rather than on an individual weight or size basis. Bacterial viability in tunicate feces was assessed by ATP analysis. Bacteria were found to be non-viable after passage through the tunicate digestive tract. Filtration of eggs or larvae of recreationally or commercially important fish is of concern. The smallest eggs (~0.6mm) reported in the Indian River Lagoon belong to Cynoscion nebulosus (spotted seatrout) and Bairdiella chrysoura (silver perch). Over the course of two hours, 72.5% of 0.5 mm glass beads (simulated fish eggs) were initially retained, but many were later expelled by the tunicates. For 1.0 mm beads, 49.4% were initially retained and for 2.0 mm beads, 43.5% were initially retained. Neither the size of the oral siphon nor the size of the overall animal was correlated to bead retention. Substrate selection was investigated using the tunicate Phallusia nigra., Newly hatched larvae preferred settling on wood (53.7%), as compared to polyethylene (30.9%), high-density polyethylene (13.0%), and polyvinyl chloride (2.4%). Overall, results of this study indicate S. plicata is very effective at removing bacteria and microalgae from estuarine waters. However, further testing is warranted regarding the unwanted removal of fish eggs and larvae before utilization of S. plicata for bioremedial purposes.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/1927312
Subject Headings: Marine bioremediation, Estuarine ecology, Water quality management, Water quality biological assessment
Format: Document (PDF)

Title: An algebraic attack on block ciphers.
Creator: Matheis, Kenneth., Charles E. Schmidt College of Science, Department of Mathematical Sciences
Abstract/Description: The aim of this work is to investigate an algebraic attack on block ciphers called Multiple Right Hand Sides (MRHS). MRHS models a block cipher as a system of n matrix equations Si := Aix = [Li], where each Li can be expressed as a set of its columns bi1, . . . , bisi . The set of solutions Ti of Si is dened as the union of the solutions of Aix = bij , and the set of solutions of the system S1, . . . , Sn is dened as the intersection of T1, . . . , Tn. Our main contribution is a hardware...
Show moreThe aim of this work is to investigate an algebraic attack on block ciphers called Multiple Right Hand Sides (MRHS). MRHS models a block cipher as a system of n matrix equations Si := Aix = [Li], where each Li can be expressed as a set of its columns bi1, . . . , bisi . The set of solutions Ti of Si is dened as the union of the solutions of Aix = bij , and the set of solutions of the system S1, . . . , Sn is dened as the intersection of T1, . . . , Tn. Our main contribution is a hardware platform which implements a particular algorithm that solves MRHS systems (and hence block ciphers). The case is made that the platform performs several thousand orders of magnitude faster than software, it costs less than US$1,000,000, and that actual times of block cipher breakage can be calculated once it is known how the corresponding software behaves. Options in MRHS are also explored with a view to increase its efficiency.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2976444
Subject Headings: Ciphers, Cryptography, Data encryption (Computer science), Computer security, Coding theory, Integrated circuits, Design and construction
Format: Document (PDF)

Title: Toxicity and availability of copper and zinc to queen conch: implications for larval recruitment in the Florida Keys.
Creator: Garr, Amber L., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The presence of heavy metals and other pollutants is detrimental to marine ecosystems. The queen conch, once an important fisheries species in the Florida Keys, has not sufficiently recovered after a 25-year fishery closure. Research has shown high levels of copper and zinc in the gonads and digestive glands of adult conch found in the nearshore waters. Four sites relevant to queen conch larval recruitment were tested in 2010 for the presence of copper and zinc in the water, phytoplankton,...
Show moreThe presence of heavy metals and other pollutants is detrimental to marine ecosystems. The queen conch, once an important fisheries species in the Florida Keys, has not sufficiently recovered after a 25-year fishery closure. Research has shown high levels of copper and zinc in the gonads and digestive glands of adult conch found in the nearshore waters. Four sites relevant to queen conch larval recruitment were tested in 2010 for the presence of copper and zinc in the water, phytoplankton, sediment, and seagrass epiphytes over seven months. Both metals were detected in all sample types and no seasonal or geographical differences were detected. Surface water concentrations from the field were used to conduct acute and chronic toxicity tests on various ages of queen conch larvae and their phytoplankton food source. When zinc concentrations (0-40 (So(Bg/L) similar to those measured in situ were used, there was no significant impact on conch larval survival although some velar lobe de velopment was impaired. However, field concentrations of copper (0-15 (So(Bg/L), which often surpassed water quality standards, negatively impacted growth, survival, and development of the larvae. Chronic exposure to copper, through the water and food, disrupted the metamorphic success of competent larvae and decreased post-metamorphosis survival. Exposure to copper at later life stages increased mortality, suggesting that heavy metals have a negative effect on larval recruitment in localized areas of the Florida Keys. Structural equation modeling revealed that copper and zinc are moving through the systems differently and are best represented by two different models.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3342102
Subject Headings: Gastropoda, Habitat, Queen conch, Conservation, Marine invertebrates, Larvae, Trace elements, Environmental aspects
Format: Document (PDF)

Title: A class of rational surfaces with a non-rational singularity explicitly given by a single equation.
Creator: Harmon, Drake., Charles E. Schmidt College of Science, Department of Mathematical Sciences
Abstract/Description: The family of algebraic surfaces X dened by the single equation zn = (y a1x) (y anx)(x 1) over an algebraically closed eld k of characteristic zero, where a1; : : : ; an 2 k are distinct, is studied. It is shown that this is a rational surface with a non-rational singularity at the origin. The ideal class group of the surface is computed. The terms of the Chase-Harrison-Rosenberg seven term exact sequence on the open complement of the ramication locus of X ! A2 are computed; the Brauer group...
Show moreThe family of algebraic surfaces X dened by the single equation zn = (y a1x) (y anx)(x 1) over an algebraically closed eld k of characteristic zero, where a1; : : : ; an 2 k are distinct, is studied. It is shown that this is a rational surface with a non-rational singularity at the origin. The ideal class group of the surface is computed. The terms of the Chase-Harrison-Rosenberg seven term exact sequence on the open complement of the ramication locus of X ! A2 are computed; the Brauer group is also studied in this unramied setting. The analysis is extended to the surface eX obtained by blowing up X at the origin. The interplay between properties of eX , determined in part by the exceptional curve E lying over the origin, and the properties of X is explored. In particular, the implications that these properties have on the Picard group of the surface X are studied.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3360782
Subject Headings: Mathematics, Galois modules (Algebra), Class field theory, Algebraic varieties, Integral equations
Format: Document (PDF)

Title: The avian community characteristics of constructed treatment wetlands of South Florida.
Creator: Beck, Tyler J., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: This study compared the avian communities of treatment wetlands in South Florida called Stormwater Treatment Wetlands (STAs) to those in natural marshes and crop lands, and examined factors that influenced the size and structure of the avian communities within the STAs. The STAs contained a more abundant, rich and distinct avian community compared to reference land types. The STAs were dominated by wintering waterfowl, and therefore community patterns fluctuated more seasonally other land...
Show moreThis study compared the avian communities of treatment wetlands in South Florida called Stormwater Treatment Wetlands (STAs) to those in natural marshes and crop lands, and examined factors that influenced the size and structure of the avian communities within the STAs. The STAs contained a more abundant, rich and distinct avian community compared to reference land types. The STAs were dominated by wintering waterfowl, and therefore community patterns fluctuated more seasonally other land types. Within the STAs, density and richness in the fall and winter were much greater in the submerged aquatic vegetation than in the mixed emergent vegetation when waterfowl were present. The STAs maintain two vegetation treatments which enhanced their biodiversity value by supporting distinct avian communities with different migratory strategies This suggests the increase in treatment wetlands could partially offset the loss of natural wetlands, but avian communities in treatment wetlands are not surrogates for natural wetlands.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3362327
Subject Headings: Constructed wetlands, Wetland hydrology, Watershed management, Habitat (Ecology), Birds, Ecology
Format: Document (PDF)

Title: Visual and electrosensory ecology of batoid elasmobranchs.
Creator: Bedore, Christine N., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The electrosensory and visual adaptations of elasmobranchs to the environment have been more studied than most other senses, however, work on these senses is mostly limited to descriptive analyses of sensitivity, morphology, and behavior. The goal of this work was to explore electrosensory and visual capabilities in a more ecological context. To gain an understanding of the content of bioelectric signals, the magnitude and frequency of these stimuli were recorded from a broad survey of...
Show moreThe electrosensory and visual adaptations of elasmobranchs to the environment have been more studied than most other senses, however, work on these senses is mostly limited to descriptive analyses of sensitivity, morphology, and behavior. The goal of this work was to explore electrosensory and visual capabilities in a more ecological context. To gain an understanding of the content of bioelectric signals, the magnitude and frequency of these stimuli were recorded from a broad survey of elasmobranch prey items... Color vision adaptations also correlated to the photic environment of each species; cownose rays inhabit turbid, green-dominated waters and had two cone visual pigments that maximize contrast of objects against the green background... Yellow stingrays were trichromatic and likely possess the ability to discriminate colors in their clear, reef and seagrass habitats, which are spectrally rich. Both species showed evidence of ultraviolet sensitivity, which may aid in predator and conspecific detection as an enhanced communication channel. Future studies should investigate the integration of sensory input and sensory involvement in intraspecific communication to gain more insight into ecological adaptations.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3362337
Subject Headings: Visual discrimination, Adaptation (Biology), Animal ecophysiology, Chondrichthyes, Physiology
Format: Document (PDF)

Title: Visual wavelength discrimination by the loggerhead turtle, Caretta caretta.
Creator: Young, Morgan, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Little is known about the visual capabilities of marine turtles. The ability to discriminate between colors has not been adequately demonstrated on the basis of behavioral criteria. I used a three-part methodology to determine if color discrimination occurred. FIrst, I exposed naèive, light-adapted hatchlings to either a blue, green or yellow light. I manipulated light intensity to obtain a behavioral phototaxis threshold to each color, which provided a range of intensities we knew turtles...
Show moreLittle is known about the visual capabilities of marine turtles. The ability to discriminate between colors has not been adequately demonstrated on the basis of behavioral criteria. I used a three-part methodology to determine if color discrimination occurred. FIrst, I exposed naèive, light-adapted hatchlings to either a blue, green or yellow light. I manipulated light intensity to obtain a behavioral phototaxis threshold to each color, which provided a range of intensities we knew turtles could detect. Second, I used food to train older turtles to swim toward one light color, and then to discriminate between the rewarded light and another light color ; lights were presented at intensities equally above the phototaxis threshold. Lastly, I varied light intensity so that brightness could not be used as a discrimination cue. Six turtles completed this task and showed a clear ability to select a rewarded over a non-rewarded color, regardless of stimulus intensity. Turtles most rapidly learned to associate shorter wavelengths (blue) with food. My results clearly show loggerheads have color vision. Further investigation is required to determine how marine turtles exploit this capability.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3352879
Subject Headings: Color vision, Visual discrimination, VIsual perception, Selectivity (Psychology), Photoreceptors, Loggerhead turtle, Orientation, Sea turtles, Orientation, Animal navigation
Format: Document (PDF)

Title: The social and environmental effects of shrimp mariculture: case studies of two coastal villages in Ecuador.
Creator: Crider, Mary C., Charles E. Schmidt College of Science, Department of Environmental Sciences
Abstract/Description: Shrimp mariculture expansion in developing countries has been criticized for its ecological destruction and the resulting social conflicts. In Ecuador, shrimp pond development particularly affects rural, coastal communities. This study addresses the environmental and social effects of shrimp farming in two Ecuadorian villages, Muisne and Bunche. Interview and survey responses indicate that locals have an overall negative view of the industry. In some instances, such as increased class...
Show moreShrimp mariculture expansion in developing countries has been criticized for its ecological destruction and the resulting social conflicts. In Ecuador, shrimp pond development particularly affects rural, coastal communities. This study addresses the environmental and social effects of shrimp farming in two Ecuadorian villages, Muisne and Bunche. Interview and survey responses indicate that locals have an overall negative view of the industry. In some instances, such as increased class marginalization through reduced access to subsistence collection areas, shrimp farming directly results in conflict. However, the data also demonstrates that ponds are only one of various stressors on mangrove ecosystems. Furthermore, mariculture provides benefits to the community, including increasing employment opportunities, the local economy, and shrimp availability. In spite of these benefits, local negative perception suggests modifications to existing regulations and educational programs are necessary to minimize impacts and help the community understand the multiple factors affecting their ecosystem and livelihoods.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3342043
Subject Headings: Mariculture, Environmental aspects, Mariculture, Social aspects, Mariculture, Economic aspects, Ecosystem management
Format: Document (PDF)

Title: A study of divisors and algebras on a double cover of the affine plane.
Creator: Bulj, Djordje., Charles E. Schmidt College of Science, Department of Mathematical Sciences
Abstract/Description: An algebraic surface defined by an equation of the form z2 = (x+a1y) ... (x + any) (x - 1) is studied, from both an algebraic and geometric point of view. It is shown that the surface is rational and contains a singular point which is nonrational. The class group of Weil divisors is computed and the Brauer group of Azumaya algebras is studied. Viewing the surface as a cyclic cover of the affine plane, all of the terms in the cohomology sequence of Chase, Harrison and Roseberg are computed.
Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3355618
Subject Headings: Algebraic number theory, Geometry, Data processing, Noncommutative differential geometry, Mathematical physics, Curves, Algebraic, Commutative rings
Format: Document (PDF)

Title: A retrospective analysis of sea turtle nest depredation patterns at Canaveral National Seashore, Florida.
Creator: Welicky, Rachel., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Nest predation can significantly reduce hatchling recruitment in sea turtle populations. This study uses 20 years of data from Canaveral National Seashore, Florida, which has pristine and altered beaches. Chi-square tests were used to determine if secondary predation events were related to the nest's primary depredation event. To determine if human beach use and nest predation are spatially or temporally linked, we ranked human beach use and examined predation frequency across all screened...
Show moreNest predation can significantly reduce hatchling recruitment in sea turtle populations. This study uses 20 years of data from Canaveral National Seashore, Florida, which has pristine and altered beaches. Chi-square tests were used to determine if secondary predation events were related to the nest's primary depredation event. To determine if human beach use and nest predation are spatially or temporally linked, we ranked human beach use and examined predation frequency across all screened and marked nests (n=40,441). Lastly, I quantified nest predation risk spatially and temporally. I found that primary predation increases the chance of a nest suffering subsequent predation. Primary and multiple predation events occurred with greater frequency in limited use areas and with lowest frequency in moderate use areas. Predation risk decreased by an average of 29.5% from 2000-2008. Nests deposited midseason were 9.8% more likely to be predated than nests deposited early or late.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2683130
Subject Headings: Predation (Biology), Wildlife managment, Sea turtles, Sea turtles, Nests
Format: Document (PDF)

Title: A role for polynucleotide phosphorylase in protecting cells and controlling RNA quality under oxidative stress.
Creator: Wu, Jinhua., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: RNA damage occurring under oxidative stress has been shown to cause RNA dysfunction and must be detrimental to cells and organisms. We propose that damaged RNA can be removed by specific RNA surveillance activities. In this work, we investigated the role of polynucleotide phosphorylase (PNPase), a 3'->5' exoribonuclease, in protecting the cells against oxidative stress and eliminating oxidatively-damaged RNA. Previously, it was reported that E. coli PNPase has a higher affinity to poly(8-oxoG...
Show moreRNA damage occurring under oxidative stress has been shown to cause RNA dysfunction and must be detrimental to cells and organisms. We propose that damaged RNA can be removed by specific RNA surveillance activities. In this work, we investigated the role of polynucleotide phosphorylase (PNPase), a 3'->5' exoribonuclease, in protecting the cells against oxidative stress and eliminating oxidatively-damaged RNA. Previously, it was reported that E. coli PNPase has a higher affinity to poly(8-oxoG:A). We further confirmed that E. coli PNPase can specifically bind to an oxidized RNA with a high affinity. An E. coli strain deficient in PNPase (pnp) is hypersensitive to hydrogen peroxide (H2O2). Importantly, the level of H2O2-induced RNA damage, measured by the content of 8-hydroxyguanosine, increases significantly in the pnp mutant cells. Consistent with the notion that PNPase plays a direct role in these processes, introduction of the pnp gene encoding E. coli PNPase can restore the viability and RNA oxidation level of the pnp mutant cells in response to H2O2 treatment. Interestingly, degradosome-association is not required for PNPase to protect cell against oxidative stress. PNPase is evolutionary conserved in most of organisms of all domains of life. The human polynucleotide phosphorylase (hPNPase) localizes mainly in mitochondria and plays pleiotropic roles in cell differentiation and has been previously shown to bind 8- oxoG-RNA with a high affinity. Here we show that similar to E. coli PNPase, hPNPase plays an indispensable role in protecting HeLa cells against oxidative stress. The viability in HeLa cell and 8-oxoG levels in RNA are inversely correlated in response to H2O2- treatment. After removal of oxidative challenge, the elevated level of 8-oxoG in RNA decreases, suggesting the existence of surveillance mechanism(s) for cleaning up oxidized RNA., We have shown that hPNPase may be responsible for the surveillance of oxidized RNA in mammalian cells.Overexpresion of hPNPase reduces RNA oxidation and increases HeLa cell viability against H2O2 insult. Conversely, hPNPase knockdown decreases the viability and increases 8-oxoG level in HeLa cells exposed to H2O2. Taken together, our results suggest that RNA oxidation is a challenging problem for living organisms, and PNPase may play an important role in protecting both prokaryotic and eukaryotic cells by limiting damage to RNA under oxidative stress.
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Date Issued: 2008
PURL: http://purl.flvc.org/FAU/186302
Subject Headings: RNA, Metabolism, Biopolymers, Physiological transport, Bacterial genetics, Proteins, Synthesis, Cellular signal transduction
Format: Document (PDF)

Title: The role of BimEL in the pathogenesis of Huntington's disease.
Creator: Leon, Rebecca, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Huntington's Disease (HD) is a devastating neurodegenerative disorder caused by an expanded polyglutamine repeat within the Huntingtin gene IT15. In this study we demonstrated that Bcl-2 interacting mediator of cell death Extra Long (BimEL) protein expression was significantly increased in cells expressing mutant Huntingtin (mHtt). Moreover, striatal BimEL expression remained high in an R6/2 HD mouse model throughout the disease progression. Utilizing novel BimEL phospho-mutants we...
Show moreHuntington's Disease (HD) is a devastating neurodegenerative disorder caused by an expanded polyglutamine repeat within the Huntingtin gene IT15. In this study we demonstrated that Bcl-2 interacting mediator of cell death Extra Long (BimEL) protein expression was significantly increased in cells expressing mutant Huntingtin (mHtt). Moreover, striatal BimEL expression remained high in an R6/2 HD mouse model throughout the disease progression. Utilizing novel BimEL phospho-mutants we demonstrated the phosphorylation of Ser65 to be important for the stabilization of BimEL. We provided evidence that impaired proteasome function, increased JNK activity and reduced striatal BDNF lead to changes in the phosphorylation of BimEL, thereby promoting its stabilization specifically within the striatum of R6/2 mice. Furthermore, knocking down BimEL expression prevented mHtt-induced cell death in a HD cell culture. Taken together, these findings suggest that BimEL may contribute to the selective neurodegeneration and pathogenesis of HD.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3355556
Subject Headings: Huntington's chorea, Pathophysiology, Huntington's chorea, Molecular aspects, Huntington's chorea, Genetic aspects, Nervous system, Degeneration, Pathophysiology, Nervous system, Degeneration, Molecular aspects, Glutamine, Pathophysiology
Format: Document (PDF)

Title: A novel optimization algorithm and other techniques in medicinal chemistry.
Creator: Santos, Radleigh G., Charles E. Schmidt College of Science, Department of Mathematical Sciences
Abstract/Description: In this dissertation we will present a stochastic optimization algorithm and use it and other mathematical techniques to tackle problems arising in medicinal chemistry. In Chapter 1, we present some background about stochastic optimization and the Accelerated Random Search (ARS) algorithm. We then present a novel improvement of the ARS algorithm, DIrected Accelerated Random Search (DARS), motivated by some theoretical results, and demonstrate through numerical results that it improves upon...
Show moreIn this dissertation we will present a stochastic optimization algorithm and use it and other mathematical techniques to tackle problems arising in medicinal chemistry. In Chapter 1, we present some background about stochastic optimization and the Accelerated Random Search (ARS) algorithm. We then present a novel improvement of the ARS algorithm, DIrected Accelerated Random Search (DARS), motivated by some theoretical results, and demonstrate through numerical results that it improves upon ARS. In Chapter 2, we use DARS and other methods to address issues arising from the use of mixture-based combinatorial libraries in drug discovery. In particular, we look at models associated with the biological activity of these mixtures and use them to answer questions about sensitivity and robustness, and also present a novel method for determining the integrity of the synthesis. Finally, in Chapter 3 we present an in-depth analysis of some statistical and mathematical techniques in combinatorial chemistry, including a novel probabilistic approach to using structural similarity to predict the activity landscape.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3352830
Subject Headings: Drugs, Design, Mathematical models, Combinatorial optimization, Combinatorial chemistry, Genetic algorithms, Mathematical optimization, Stochastic processes
Format: Document (PDF)

Title: A min/max algorithm for cubic splines over k-partitions.
Creator: Golinko, Eric David, Charles E. Schmidt College of Science, Department of Mathematical Sciences
Abstract/Description: The focus of this thesis is to statistically model violent crime rates against population over the years 1960-2009 for the United States. We approach this question as to be of interest since the trend of population for individual states follows different patterns. We propose here a method which employs cubic spline regression modeling. First we introduce a minimum/maximum algorithm that will identify potential knots. Then we employ least squares estimation to find potential regression...
Show moreThe focus of this thesis is to statistically model violent crime rates against population over the years 1960-2009 for the United States. We approach this question as to be of interest since the trend of population for individual states follows different patterns. We propose here a method which employs cubic spline regression modeling. First we introduce a minimum/maximum algorithm that will identify potential knots. Then we employ least squares estimation to find potential regression coefficients based upon the cubic spline model and the knots chosen by the minimum/maximum algorithm. We then utilize the best subsets regression method to aid in model selection in which we find the minimum value of the Bayesian Information Criteria. Finally, we preent the R2adj as a measure of overall goodness of fit of our selected model. We have found among the fifty states and Washington D.C., 42 out of 51 showed an R2adj value that was greater than 90%. We also present an overall model of the United States. Also, we show additional applications our algorithm for data which show a non linear association. It is hoped that our method can serve as a unified model for violent crime rate over future years.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3342107
Subject Headings: Spline theory, Data processing, Bayesian statistical decision theory, Data processing, Neural networks (Computer science), Mathematical statistics, Uncertainty (Information theory), Probabilities, Regression analysis
Format: Document (PDF)

Title: Unique decomposition of direct sums of ideals.
Creator: Ay, Basak., Charles E. Schmidt College of Science, Department of Mathematical Sciences
Abstract/Description: We say that a commutative ring R has the unique decomposition into ideals (UDI) property if, for any R-module which decomposes into a finite direct sum of indecomposable ideals, this decomposition is unique up to the order and isomorphism class of the ideals. In a 2001 paper, Goeters and Olberding characterize the UDI property for Noetherian integral domains. In Chapters 1-3 the UDI property for reduced Noetherian rings is characterized. In Chapter 4 it is shown that overrings of one...
Show moreWe say that a commutative ring R has the unique decomposition into ideals (UDI) property if, for any R-module which decomposes into a finite direct sum of indecomposable ideals, this decomposition is unique up to the order and isomorphism class of the ideals. In a 2001 paper, Goeters and Olberding characterize the UDI property for Noetherian integral domains. In Chapters 1-3 the UDI property for reduced Noetherian rings is characterized. In Chapter 4 it is shown that overrings of one-dimensional reduced commutative Noetherian rings with the UDI property have the UDI property, also. In Chapter 5 we show that the UDI property implies the Krull-Schmidt property for direct sums of torsion-free rank one modules for a reduced local commutative Noetherian one-dimensional ring R.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2683133
Subject Headings: Algebraic number theory, Modules (Algebra), Noetherian rings, Commutative rings, Algebra, Abstract
Format: Document (PDF)

Title: The existence of minimal logarithmic signatures for classical groups.
Creator: Singhi, Nikhil., Charles E. Schmidt College of Science, Department of Mathematical Sciences
Abstract/Description: A logarithmic signature (LS) for a nite group G is an ordered tuple = [A1;A2; : : : ;An] of subsets Ai of G, such that every element g 2 G can be expressed uniquely as a product g = a1a2 : : : ; an, where ai 2 Ai. Logarithmic signatures were dened by Magliveras in the late 1970's for arbitrary nite groups in the context of cryptography. They were also studied for abelian groups by Hajos in the 1930's. The length of an LS is defined to be `() = Pn i=1 jAij. It can be easily seen that for a...
Show moreA logarithmic signature (LS) for a nite group G is an ordered tuple = [A1;A2; : : : ;An] of subsets Ai of G, such that every element g 2 G can be expressed uniquely as a product g = a1a2 : : : ; an, where ai 2 Ai. Logarithmic signatures were dened by Magliveras in the late 1970's for arbitrary nite groups in the context of cryptography. They were also studied for abelian groups by Hajos in the 1930's. The length of an LS is defined to be `() = Pn i=1 jAij. It can be easily seen that for a group G of order Qk j=1 pj mj , the length of any LS for G satises `() Pk j=1mjpj . An LS for which this lower bound is achieved is called a minimal logarithmic signature (MLS). The MLS conjecture states that every finite simple group has an MLS. If the conjecture is true then every finite group will have an MLS. The conjecture was shown to be true by a number of researchers for a few classes of finite simple groups. However, the problem is still wide open. This dissertation addresses the MLS conjecture for the classical simple groups. In particular, it is shown that MLS's exist for the symplectic groups Sp2n(q), the orthogonal groups O 2n(q0) and the corresponding simple groups PSp2n(q) and 2n(q0) for all n 2 N, prime power q and even prime power q0. The existence of an MLS is also shown for all unitary groups GUn(q) for all odd n and q = 2s under the assumption that an MLS exists for GUn 1(q). The methods used are very general and algorithmic in nature and may be useful for studying all nite simple groups of Lie type and possibly also the sporadic groups. The blocks of logarithmic signatures constructed in this dissertation have cyclic structure and provide a sort of cyclic decomposition for these classical groups.
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Date Issued: 2011
PURL: http://purl.flvc.org/FAU/3172943
Subject Headings: Finite groups, Abelian groups, Number theory, Combinatorial group theory, Mathematical recreations, Linear algebraic groups, Lie groups
Format: Document (PDF)

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