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- Title
- Effects of stressors on differential gene expression and secondary metabolites by Axinella corrugata.
- Creator
- Grima, Jennifer., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Sponges are an important source of bioactive marine natural products, or secondary metabolites. The common Caribbean reef sponge, Axinella corrugata, produces an antitumor and antibacterial chemical, stevensine. This study determined whether environmental stressors, such as elevated temperature and exposure to Amphibalanus amphitrite larvae, affect the production of stevensine by A.corrugata and if the stressors caused A.corrugata to exhibit differential gene expression. Temperature stress...
Show moreSponges are an important source of bioactive marine natural products, or secondary metabolites. The common Caribbean reef sponge, Axinella corrugata, produces an antitumor and antibacterial chemical, stevensine. This study determined whether environmental stressors, such as elevated temperature and exposure to Amphibalanus amphitrite larvae, affect the production of stevensine by A.corrugata and if the stressors caused A.corrugata to exhibit differential gene expression. Temperature stress resulted in no significant change in the production of stevensine; only two genes were significantly differentially expressed, including hsp70. Larval stressed resulted in increased production of stevensine and significant differential gene expression (more than seventy genes). This study suggests that A.corrugata may be resilient to elevations in temperature and that one of stevensine's roles in nature is as an antifoulant.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3360781
- Subject Headings
- Axinellida, Sponges, Marine pharmacology, Adaptation (Biology), Gene expression, Genetic regulation, Stress (Physiology), Ecophysiology
- Format
- Document (PDF)
- Title
- Engineered and natural TIMP mutations.
- Creator
- Hamze, Asmaa Bilal., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Tissue inhibitors of metalloproteinases (TIMPs) comprise a family of four proteins in humans that modulate the turnover of the extracellular matrix by regulating the activities of endopeptidases that catalyze its degradation, especially the matrix metalloproteinases (MMP). In general, the four TIMPs are broad-spectrum tight binding inhibitors of MMPs with individual differences in specificity. In this study, we attempted to understand the basis of such variation by using membrane type-1 MMP ...
Show moreTissue inhibitors of metalloproteinases (TIMPs) comprise a family of four proteins in humans that modulate the turnover of the extracellular matrix by regulating the activities of endopeptidases that catalyze its degradation, especially the matrix metalloproteinases (MMP). In general, the four TIMPs are broad-spectrum tight binding inhibitors of MMPs with individual differences in specificity. In this study, we attempted to understand the basis of such variation by using membrane type-1 MMP (MT1-MMP) as a model, since it is inefficiently inhibited by TIMP-1 in contrast with the other TIMPs. We designed and engineered mutations in the N-domain of TIMP-1, based on current knowledge of TIMP interactions. By measuring inhibition levels of each mutant against several MMPs, including MT1-MMP, we were able to obtain a triple mutant with an vii improved affinity for MT1-MMP., Our results, along with previous data, confirm that multiple residues in the critical interface segments between TIMPs and MMPs, namely at positions 2, 4, 5, 6, and 98, are key in determining the basic interaction between the two molecules. The second part of this work focused on naturally occurring mutations in TIMP-3 which cause an early form of macular degeneration called Sorsby's Fundus Dystrophy (SFD). The TIMP-3 mutants identified so far share certain features but the mechanism by which they result in macular disease is not yet understood. As an initial step, we expressed recombinant TIMP-3 carrying a truncation mutation, glutamic acid 139 to a stop codon (E139X), and assessed its activity towards representative MMPs and tumor necrosis factor-(Sa (Bconverting enzyme, another metalloproteinase normally inhibited by TIMP-3. Our results indicate that this mutation does not impair the inhibitory activity of TIMP-3., Expression of this mutant in mammalian retinal cells revealed a difference in localization between wild-type and E139X mutant TIMP-3. Therefore, we concluded that the SFD mutations may actually influence the processing and/or binding properties of TIMP-3 in the retina.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/186296
- Subject Headings
- Proteolytic enzymes, Extracellular matrix proteins, Metalloproteinases, Inhibitors, Apoptosis, Retinal degeneration, Research
- Format
- Document (PDF)
- Title
- Effects of mid-incubation egg movement on loggerhead (Caretta caretta) turtle hatch success and embryo development.
- Creator
- Ahles, Natasha M., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Due to an emergency status dune restoration project following Subtropical Storm Andrea in 2007 on Singer Island, Florida, nests needed to be moved during early to mid-incubation. Nesting success was compared between those moved mid-incubation, moved within 12h to either a native sand incubation area or a renourished sand incubation area, and those left in-situ. Nests moved within 12h to the native sand had a significantly larger proportion of pipped hatchlings. Nests moved mid-incubation had...
Show moreDue to an emergency status dune restoration project following Subtropical Storm Andrea in 2007 on Singer Island, Florida, nests needed to be moved during early to mid-incubation. Nesting success was compared between those moved mid-incubation, moved within 12h to either a native sand incubation area or a renourished sand incubation area, and those left in-situ. Nests moved within 12h to the native sand had a significantly larger proportion of pipped hatchlings. Nests moved mid-incubation had a significantly lower proportion of hatched eggs as well as emergent hatchlings. The stage in which embryonic development was arrested corresponded to the stage the embryos were in during the time of movement; indicating movement was the cause of death. When comparing nests moved within the initial 2.5 weeks of development to those moved after 2.5 weeks of development, there was no significant difference in hatching success.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/221948
- Subject Headings
- Sea turtles, Embryology, Wildlife conservation
- Format
- Document (PDF)
- Title
- Design and analysis of key establishment protocols.
- Creator
- Neupane, Kashi., Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
Consider a scenario where a server S shares a symmetric key kU with each user U. Building on a 2-party solution of Bohli et al., we describe an authenticated 3-party key establishment which remains secure if a computational Bilinear Diffie Hellman problem is hard or the server is uncorrupted. If the BDH assumption holds during a protocol execution, but is invalidated later, entity authentication and integrity of the protocol are still guaranteed. Key establishment protocols based on hardness...
Show moreConsider a scenario where a server S shares a symmetric key kU with each user U. Building on a 2-party solution of Bohli et al., we describe an authenticated 3-party key establishment which remains secure if a computational Bilinear Diffie Hellman problem is hard or the server is uncorrupted. If the BDH assumption holds during a protocol execution, but is invalidated later, entity authentication and integrity of the protocol are still guaranteed. Key establishment protocols based on hardness assumptions, such as discrete logarithm problem (DLP) and integer factorization problem (IFP) are vulnerable to quantum computer attacks, whereas the protocols based on other hardness assumptions, such as conjugacy search problem and decomposition search problem can resist such attacks. The existing protocols based on the hardness assumptions which can resist quantum computer attacks are only passively secure. Compilers are used to convert a passively secure protocol to an actively secure protoc ol. Compilers involve some tools such as, signature scheme and a collision-resistant hash function. If there are only passively secure protocols but not a signature scheme based on same assumption then the application of existing compilers requires the use of such tools based on different assumptions. But the introduction of new tools, based on different assumptions, makes the new actively secure protocol rely on more than one hardness assumptions. We offer an approach to derive an actively secure two-party protocol from a passively secure two-party protocol without introducing further hardness assumptions. This serves as a useful formal tool to transform any basic algebric method of public key cryptography to the real world applicaticable cryptographic scheme. In a recent preprint, Vivek et al. propose a compiler to transform a passively secure 3-party key establishment to a passively secure group key establishment. To achieve active security, they apply this compiler to Joux's, protoc ol and apply a construction by Katz and Yung, resulting in a 3-round group key establishment. In this reserach, we show how Joux's protocol can be extended to an actively secure group key establishment with two rounds. The resulting solution is in the standard model, builds on a bilinear Diffie-Hellman assumption and offers forward security as well as strong entity authentication. If strong entity authentication is not required, then one half of the participants does not have to send any message in the second round, which may be of interest for scenarios where communication efficiency is a main concern.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342239
- Subject Headings
- Computer networks, Security measures, Computer network protocols, Data encryption (Computer science), Public key infrastructure (Computer security)
- Format
- Document (PDF)
- Title
- Activators and repressors of transcription: using bioinformatics approaches to analyze and group human transcription factors.
- Creator
- Savitskaya, Ala., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Transcription factors are macromolecules that are involved in transcriptional regulation by interacting with specific DNA regions, and they can cause activation or silencing of their target genes. Gene regulation by transcriptional control explains different biological processes such as development, function, and disease. Even though transcriptional control has been of great interest for molecular biology, much still remains unknown. This study was designed to generate the most current list...
Show moreTranscription factors are macromolecules that are involved in transcriptional regulation by interacting with specific DNA regions, and they can cause activation or silencing of their target genes. Gene regulation by transcriptional control explains different biological processes such as development, function, and disease. Even though transcriptional control has been of great interest for molecular biology, much still remains unknown. This study was designed to generate the most current list of human transcription factor genes. Unique entries of transcription factor genes were collected and entered into Microsoft Office 2007 Access Database along with information about each gene. Microsoft Office 2007 Access tools were used to analyze and group collected entries according to different properties such as activator or repressor record, or presence of certain protein domains. Furthermore, protein sequence alignments of members of different groups were performed, and phylogenetic trees were used to analyze relationship between different members of each group. This work contributes to the existing knowledge of transcriptional regulation in humans.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1930495
- Subject Headings
- Transcription factors, Genetic transcription, Regulation, Cellular signal transduction, DNA microarrays, Bioinformatics
- Format
- Document (PDF)
- Title
- Activity patterns of green iguana (Iguana iguana) at Hugh Taylor Birch State Park, Fort Lauderdale, Florida.
- Creator
- Sekscienski, Stacey R., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Activity patterns of Iguana iguana from two locations within Hugh Taylor Birch State Park, Fort Lauderdale, Florida were documented and examined. Between May 1, 2006 to April 20, 2007, I. iguana were observed on a routine basis and activities were documented as one of six major activity categories (basking, locomotion, foraging, resting, visual signaling, and other). Data was analyzed to determine differences between activity patterns of I. iguana relative to sites, seasons, and size category...
Show moreActivity patterns of Iguana iguana from two locations within Hugh Taylor Birch State Park, Fort Lauderdale, Florida were documented and examined. Between May 1, 2006 to April 20, 2007, I. iguana were observed on a routine basis and activities were documented as one of six major activity categories (basking, locomotion, foraging, resting, visual signaling, and other). Data was analyzed to determine differences between activity patterns of I. iguana relative to sites, seasons, and size category within the park. Iguana iguana spent more time basking at Site 1 than Site 2. Size 4 animals which consisted of dominant adult males, spent more time basking than other males and adult females. Size 4 animals also spent less time foraging than hatchlings, juveniles, and other adults. These results complement the existing research on behavior of I. iguana and may be useful in determining invasive control efforts of I. iguana in Florida.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3359162
- Subject Headings
- Green iguana, Behavior, Adaptation (Biology)
- Format
- Document (PDF)
- Title
- AUC estimation under various survival models.
- Creator
- Chang, Fazhe., Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
In the medical science, the receiving operationg characteristic (ROC) curve is a graphical representation to evaluate the accuracy of a medical diagnostic test for any cut-off point. The area under the ROC curve (AUC) is an overall performance measure for a diagnostic test. There are two parts in this dissertation. In the first part, we study the properties of bi-Exponentiated Weibull models. FIrst, we derive a general moment formula for single Exponentiated Weibull models. Then we move on to...
Show moreIn the medical science, the receiving operationg characteristic (ROC) curve is a graphical representation to evaluate the accuracy of a medical diagnostic test for any cut-off point. The area under the ROC curve (AUC) is an overall performance measure for a diagnostic test. There are two parts in this dissertation. In the first part, we study the properties of bi-Exponentiated Weibull models. FIrst, we derive a general moment formula for single Exponentiated Weibull models. Then we move on to derive the precise formula of AUC and study the maximus likelihood estimation (MLE) of the AUC. Finally, we obtain the asymptotoc distribution of the estimated AUC. Simulation studies are used to check the performance of MLE of AUC under the moderate sample sizes. The second part fo the dissertation is to study the estimation of AUC under the crossing model, which extends the AUC formula in Gonen and Heller (2007).
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3359287
- Subject Headings
- Receiver operating characteristic curves, Medical screening, Statistical methods, Diagnosis, Statistical methods, Smoothing (Statistics)
- Format
- Document (PDF)
- Title
- Identification of longitudinals lacking (LOLA) target genes in Drosophila melanogaster.
- Creator
- Qureshi, Bazila., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Longitudinals lacking gene (LOLA) is a transcription factor that is involved in a variety of axon guidance decisions in Drosophila melanogaster nervous system. Besides having a role as an epigenetic silencer and in the programmed cell death in Drosophila's ovary, this gene is also an example of complex transcription unit. LOLA is a transcription repressor and can generate 17 DNA - binding isoforms, through alternative splicing, each containing distinct zinc-finger proteins. This unique...
Show moreLongitudinals lacking gene (LOLA) is a transcription factor that is involved in a variety of axon guidance decisions in Drosophila melanogaster nervous system. Besides having a role as an epigenetic silencer and in the programmed cell death in Drosophila's ovary, this gene is also an example of complex transcription unit. LOLA is a transcription repressor and can generate 17 DNA - binding isoforms, through alternative splicing, each containing distinct zinc-finger proteins. This unique DNAbinding binding sequence to which LOLA-ZFP binds has been determined for four of the lola isoforms F, J, P and K. Also, bioinformatics' tool approach has been taken to identify the target genes that are regulated by these four LOLA splice variants. Future work will be done for the five other LOLA isoforms to categorize their putative DNA-binding sequences and subsequently their protein interactions.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2684893
- Subject Headings
- Transcription factors, Cellular signal transduction, Zinc-finger proteins, Synthesis, Genetic transcription, Regulation, Drosophila melanogaster, Cytogenetics, Gene expression
- Format
- Document (PDF)
- Title
- Identification and characterization of mutations in the Drosophila mitochondrial translation elongation factor iconoclast.
- Creator
- Trivigno, Catherine F., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Mitochondrial disorders resulting from defects in oxidative phosphorylation are the most common form of inherited metabolic disease. Mutations in the human mitochondrial translation elongation factor GFM1 have recently been shown to cause the lethal pediatric disorder Combined Oxidative Phosphorylation Deficiency Syndrome (COXPD1). Children harboring mutations in GFM1 exhibit severe developmental, metabolic and neurological abnormalities. This work describes the identification and extensive...
Show moreMitochondrial disorders resulting from defects in oxidative phosphorylation are the most common form of inherited metabolic disease. Mutations in the human mitochondrial translation elongation factor GFM1 have recently been shown to cause the lethal pediatric disorder Combined Oxidative Phosphorylation Deficiency Syndrome (COXPD1). Children harboring mutations in GFM1 exhibit severe developmental, metabolic and neurological abnormalities. This work describes the identification and extensive characterization of the first known mutations in iconoclast (ico), the Drosophila orthologue of GFM1. Expression of human GFM1 can rescue ico null mutants, demonstrating functional conservation between the human and fly proteins. While point mutations in ico result in developmental defects and death during embryogenesis, animals null for ico survive until the second or third instar larval stage. These results indicate that in addition to loss-of-function consequences, point mutations in ico appear to produce toxic proteins with antimorphic or neomorphic effects. Consistent with this hypothesis, transgenic expression of a mutant ICO protein is lethal when expressed during development and inhibits growth when expressed in wing discs. In addition, animals with a single copy of an ico point mutation are more sensitive to acute hyperthermic or hypoxic stress. Removal of the positively-charged tail of the protein abolishes the toxic effects of mutant ICO, demonstrating that this domain is necessary for the harmful gain-of-function phenotypes observed in ico point mutants., Further, expression of GFP-tagged constructs indicates that the C-terminal tail enhances ectopic nuclear localization of mutant ICO, suggesting that mislocalization of the protein may play a role in the antimorphic effects of mutant ICO. Taken together, these results illustrate that in addition to loss-of-function effects, gain-of-function effects can contribute significantly to the pathology caused by mutation in mitochondrial translation elongation factors.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2705081
- Subject Headings
- Drosophila melanogaster, Cytogenetics, Mutation (Biology), Mitochondrial DNA, Cell metabolism, Cellular signal transduction, Oxidation, Physiological, Genetic transcription, Regulation
- Format
- Document (PDF)
- Title
- Habitat selection among fishes and shrimp in the pelagic Sargassum community: the role of habitat architecture.
- Creator
- Bennice, Chelsea, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Pelagic Sargassum was used to determine the effects of habitat architecture for one species of shrimp (Leander tenuicornis) and two species of fish (Stephanolepis hispidus and Histrio histrio). Inter-thallus spacing (low, medium, and high) and depth (shallow versus deep) were manipulated independently to test whether the spatial components of habitat architecture. Two differing habitats (Sargassum versus seagrass species) were tested for the structural component of habitat architecture. There...
Show morePelagic Sargassum was used to determine the effects of habitat architecture for one species of shrimp (Leander tenuicornis) and two species of fish (Stephanolepis hispidus and Histrio histrio). Inter-thallus spacing (low, medium, and high) and depth (shallow versus deep) were manipulated independently to test whether the spatial components of habitat architecture. Two differing habitats (Sargassum versus seagrass species) were tested for the structural component of habitat architecture. There were no significant results for inter-thallus spacing experiments for L. tenuicornis and S. hispidus. H histrio selected habitats with medium inter-thallus spacing in two treatments. Large individual H. histrio contributed mostly to the significant effects. All three species selected habitats with a greater depth aspect. Finally, L. tenuicornis and H. histrio selected habitats with greater structural complexity (i.e., Sargassum). These results demonstrate clearly that habitat architecture of Sargassum influences habitat selection by these shrimp and fishes.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358284
- Subject Headings
- Habitat (Ecology), Sargassum, Ecology, Animal behavior, Predation (Biology)
- Format
- Document (PDF)
- Title
- In search of MMP specific inhibitors: protein engineering of TIMPs.
- Creator
- Bahudhanapati, Harinathachari., Charles E. Schmidt College of Science, Department of Biomedical Science
- Abstract/Description
-
The tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of the matrix metalloproteinases (MMPs). Since unregulated MMP activities are linked to arthritis, cancer, and atherosclerosis, TIMP variants that are selective inhibitors of disease-related MMPs have potential therapeutic value. The structures of TIMP/MMP complexes reveal that most interactions with the MMP involve the N-terminal region of TIMP and the C-D B-strand connector which occupy the primed (right side of...
Show moreThe tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of the matrix metalloproteinases (MMPs). Since unregulated MMP activities are linked to arthritis, cancer, and atherosclerosis, TIMP variants that are selective inhibitors of disease-related MMPs have potential therapeutic value. The structures of TIMP/MMP complexes reveal that most interactions with the MMP involve the N-terminal region of TIMP and the C-D B-strand connector which occupy the primed (right side of the active site) and unprimed (left side) regions of the active site. Substitutions for Thr2 of N-TIMP- 1 strongly influence MMP selectivity. In this study we found that Arg and Gly, which generally reduce MMP affinity, have less effect on binding to MMP-9. When the Arg mutation is added to the NTIMP-1 mutant with AB loop of TIMP-2, it produced a gelatinase-specific inhibitor with Ki values of 2.8 and 0.4 nM for MMP-2 and MMP-9, respectively. The Gly mutant has a Ki of 2.1 nM for MMP-9 and > 40 uM for MMP-2, indicating that engineered TIMPs can discriminate between MMPs in the same subfamily. In collaboration with Dr. Yingnan Zhang at Genentech, we have developed a protocol for the phage display of full-length human TIMP-2 to identify high-affinity selective inhibitors of human MMP-1, a protease that plays a role in cleaving extracellular matrix (ECM) components, connective tissue remodeling during development, angiogenesis, and apoptosis. We have generated a library containing 2x1010 variants of TIMP-2 randomized at residues 2-6 (L1), at residues 34-40 (L2) and 67-70 (L3)., The L1 library yielded a positive signal for MMP-1 binding. Clones from the L1 library, designated TM1, TM8, TM13, and TM14, were isolated after 5 rounds of selection on immobilized MMP-1 and MMP-3 and found to show a greater selectivity for MMP-1 relative to MMP-3. TM8, which has Ser2 to Asp and Ser4 to Ala substitutions, showed the greatest apparent selectivity of 10-fold toward MMP-1 compared to MMP-3. The various mutations identified by phage display were introduced into recombinant Nterminal TIMP-2 and the variants characterized as inhibitors of an array of MMP catalytic domains. The TM8-based mutant showed pronounced selectivity (> 1000-fold for MMP-1 vs. MMP-3) and may be a step towards the generation of MMP-1-specific inhibitors. Molecular modeling was used to rationalize the structural basis of MMP selectivity in the mutants.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/221942
- Subject Headings
- Metalloproteinases, Inhibitors, Apoptosis, Extracellular matrix proteins, Proteolytic enzymes
- Format
- Document (PDF)
- Title
- Genetic differentiation among populations of bald eagles, Haliaeetus leucocephalus.
- Creator
- Helmick, Ericka Elizabeth., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The bald eagle, Haliaeetus leucocephalus, population declined dramatically in the early 20th century reducing the population from tens of thousands of birds within the lower 48 states, to
Show moreThe bald eagle, Haliaeetus leucocephalus, population declined dramatically in the early 20th century reducing the population from tens of thousands of birds within the lower 48 states, to <450 pairs of birds, effectively inducing a population bottleneck. The overall population has recovered and was removed from the endangered species list in 2007. This study investigates whether such overall population statistics are appropriate descriptors for this widespread species. I investigated the genetic differentiation between three populations of bald eagles from Alaska, North Florida and Florida Bay using both mitochondrial and nuclear DNA loci to determine whether discrete subpopulations comprise the broad range. Significant FST values, for both mtDNA and microsatellites, were found between both Florida populations and Alaska, but not within Florida populations. Results indicate that there is strong population structure, rejecting the null hypothesis of a panmictic population. Future conservation efforts should focus on subpopulations rather than the overall population.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3171395
- Subject Headings
- Wildlife conservation, Birds, Molecular genetics, Gene targeting, Developmental biology, Biochemical markers
- Format
- Document (PDF)
- Title
- Implementation and comparison of the Golay and first order Reed-Muller codes.
- Creator
- Shukina, Olga., Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
In this project we perform data transmission across noisy channels and recover the message first by using the Golay code, and then by using the first-order Reed- Muller code. The main objective of this thesis is to determine which code among the above two is more efficient for text message transmission by applying the two codes to exactly the same data with the same channel error bit probabilities. We use the comparison of the error-correcting capability and the practical speed of the Golay...
Show moreIn this project we perform data transmission across noisy channels and recover the message first by using the Golay code, and then by using the first-order Reed- Muller code. The main objective of this thesis is to determine which code among the above two is more efficient for text message transmission by applying the two codes to exactly the same data with the same channel error bit probabilities. We use the comparison of the error-correcting capability and the practical speed of the Golay code and the first-order Reed-Muller code to meet our goal.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362579
- Subject Headings
- Error-correcting codes (Information theory), Coding theory, Computer algorithms, Digital modulation
- Format
- Document (PDF)
- Title
- Nutrition and habitat driven foraging of wild dolphins in the Bahamas: a recipe for prey.
- Creator
- Malinowski, Christopher R., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Two sympatric dolphin species, Stenella frontalis and Tursiops truncatus, resident to Little Bahama Bank, Bahamas were found to mostly forage independent of one another, but occasionally foraged in mixed groups. Analysis of over 20 years of data revealed the degree of overlap to be minimal with spatially distinct regions identified for both species, environmental segregation based on depth, bottom type, temperature, and time of day. Results based on observational data indicated significant...
Show moreTwo sympatric dolphin species, Stenella frontalis and Tursiops truncatus, resident to Little Bahama Bank, Bahamas were found to mostly forage independent of one another, but occasionally foraged in mixed groups. Analysis of over 20 years of data revealed the degree of overlap to be minimal with spatially distinct regions identified for both species, environmental segregation based on depth, bottom type, temperature, and time of day. Results based on observational data indicated significant differences in group size and selected prey. For S. frontalis, lactating females had the most distinct diet, which differed from that of non-reproductively active (NRA) females. Pregnant females had ambiguous prey use results, but diet differences were revealed through nutritional analysis. Lactating females had a higher intake of all nutrients (% moisture, % lipid, % protein, and calories) than pregnant females but lower than NRA females. Mother and calf pairs selected prey for caloric and moisture values. The influence of calves on foraging groups was reflected through discrete differences in all nutrients. Males and females appeared to select the same major prey, but female prey use was much more diverse.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3318668
- Subject Headings
- Dolphins, Habitat, Predatory marine animals, Ecology, Marine ecosystem management, Predation (Biology), Aquatic mammals, Behavior
- Format
- Document (PDF)
- Title
- Molecular and phenotypic characterization of MsrA MsrB mutants of Drosophila melanogaster.
- Creator
- Robbins, Kelli., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Aging is a multifactoral biological process of progressive and deleterious changes partially attributed to a build up of oxidatively damaged biomolecules resulting from attacks by free radicals. Methionine sulfoxide reductases (Msrs) are enzymes that repair oxidized methionine (Met) residues found in proteins. Oxidized Met produces two enantiomers, Met-S-(o) and Met-R-(o), reduced by MsrA and MsrB respectively. Unlike other model organisms, our MsrA null fly mutant did not display increased...
Show moreAging is a multifactoral biological process of progressive and deleterious changes partially attributed to a build up of oxidatively damaged biomolecules resulting from attacks by free radicals. Methionine sulfoxide reductases (Msrs) are enzymes that repair oxidized methionine (Met) residues found in proteins. Oxidized Met produces two enantiomers, Met-S-(o) and Met-R-(o), reduced by MsrA and MsrB respectively. Unlike other model organisms, our MsrA null fly mutant did not display increased sensitivity to oxidative stress or shortened lifespan, suggesting that in Drosophila, having either a functional copy of either Msr is sufficient. Here, two Msr mutant types were phenotypically assayed against isogenic controls. Results suggest that only the loss of both MsrA and MsrB produces increased sensitivity to oxidative stress and shortened lifespan, while locomotor defects became more severe with the full Msr knockout fly.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/359920
- Subject Headings
- Genetic regulation, Oxidation-reduction reaction, Proteins, Chemical modification, Aging, Molecular aspects, Mutation (Biology), Cell metabolism, Mitochondrial DNA
- Format
- Document (PDF)
- Title
- Phosphate-associated phenotype plasticity as a driver of cattail invasion in the sawgass-dominated Everglades.
- Creator
- Webb, James., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
In plants, phenotypic plasticity, the ability to morphologically adapt to new or broad environmental conditions, is a consequence of long-term evolutionary genetic processes. Thus, plants adapted to low phosphate (P) environments exhibit only limited plasticity to take advantage of nutrient enrichment, a global phenomenon in terrestrial and aquatic environments. In the face of anthropogenic P-enrichment, low nutrient adapted resident plant species are frequently displaced by species with high...
Show moreIn plants, phenotypic plasticity, the ability to morphologically adapt to new or broad environmental conditions, is a consequence of long-term evolutionary genetic processes. Thus, plants adapted to low phosphate (P) environments exhibit only limited plasticity to take advantage of nutrient enrichment, a global phenomenon in terrestrial and aquatic environments. In the face of anthropogenic P-enrichment, low nutrient adapted resident plant species are frequently displaced by species with high morphological and genetic plasticity. However, it remains unclear whether plasticity is systemically expressed across molecular, biochemical, physiological, and morphological processes that ultimately contribute to the root and shoot phenotypes of plants. In this study, we demonstrated high plasticity in root-borne traits of sawgrass (Cladium jamaicense), the dominant plant species of the P-impoverished Everglades, and counter the idea of inflexibility in low P adapted species. However, sawgras s expressed inflexibility in processes contributing to shoot phenotypes, in contrast to cattail, which was highly plastic in shoot characteristics vii in response to P enrichment. In fact, plasticity in cattail shoots is likely a function of its growth response to P that was globally regulated by P-availability at the level of transcription. Plasticity and inflexibility in the growth of both species also diverged in their allocation of P to the chloroplast for growth in cattail versus the vacuole for P storage in sawgrass. In the Everglades, anthropogenic P-enrichment has changed the environment from a P-limited condition, where plasticity in root-borne traits of sawgrass was advantageous, to one of light-competition, where plasticity in shoot-borne traits drives competitive dominance by cattail., We hypothesize that these shifts in plasticity competitive advantage from root to shoots has been a major driver of cattail expansion in the Everglades ecosystem. Further, this understanding of how natural plant species adapt and shift in response to nutrient availability could also be used a model system to optimize agricultural systems to increase efficiencies in food production and protect low nutrient adapted natural systems from cultural eutrophication.
Show less - Date Issued
- 2010, 2010
- PURL
- http://purl.flvc.org/FAU/2979377
- Subject Headings
- Ecosystem management, Vegatation dynamics, Phosphorous, Physiological transport, Biogeochemical cycles
- Format
- Document (PDF)
- Title
- Prevalence of antibiotic resistant commensal bacteria in endangered avian species.
- Creator
- Efstathion, Caroline Ann, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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This study examines prevalence of antibiotic resistant bacteria in Amazon parrots in three different groups, one wild and two captive. Commensal bacteria were isolated from 24 parrots and screened for antibiotic resistance. Culture-based and molecular methods were used and a total of 546 isolates from the genus Staphylococcus and Rothia were obtained. Antibiotic resistance was found in all parrot groups in 161 isolates with 48 having multi-drug resistance. The highest frequency of resistance...
Show moreThis study examines prevalence of antibiotic resistant bacteria in Amazon parrots in three different groups, one wild and two captive. Commensal bacteria were isolated from 24 parrots and screened for antibiotic resistance. Culture-based and molecular methods were used and a total of 546 isolates from the genus Staphylococcus and Rothia were obtained. Antibiotic resistance was found in all parrot groups in 161 isolates with 48 having multi-drug resistance. The highest frequency of resistance was found to Enrofloxacin and Amoxicillin/Clavulnate though all antibiotics tested were resisted by some bacterial isolates. Both captive groups exhibited more resistant individuals than the wild. This study concluded that antibiotic resistant commensal bacteria in Amazons are common; however, patterns found cannot be explained by antibiotic use. A high rate of multi-drug resistance was detected in more common mannitol non-fermenting Staphylococcus spp., and drug resistant detected in Rothia spp. may indicate a future role in disease.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3170956
- Subject Headings
- Parrots, Drug resistance in microoganisms, Wildlife conservation, Host-bacteria relationship, Microbial ecology
- Format
- Document (PDF)
- Title
- On projected planes.
- Creator
- Caliskan, Cafer., Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
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This work was motivated by the well-known question: "Does there exist a nondesarguesian projective plane of prime order?" For a prime p 1, determine all subplanes of order p up to collineations, and check whether one of these is non-desarguesian." In this manuscript we use a group-theoretic methodology to determine the subplane structures of some non-desarguesian planes. In particular, we determine orbit representatives of all proper Q-subplanes both of a Veblen-Wedderburn (VW) plane of...
Show moreThis work was motivated by the well-known question: "Does there exist a nondesarguesian projective plane of prime order?" For a prime p < 11, there is only the pappian plane of order p. Hence, such planes are indeed desarguesian. Thus, it is of interest to examine whether there are non-desarguesian planes of order 11. A suggestion by Ascher Wagner in 1985 was made to Spyros S. Magliveras: "Begin with a non-desarguesian plane of order pk, k > 1, determine all subplanes of order p up to collineations, and check whether one of these is non-desarguesian." In this manuscript we use a group-theoretic methodology to determine the subplane structures of some non-desarguesian planes. In particular, we determine orbit representatives of all proper Q-subplanes both of a Veblen-Wedderburn (VW) plane of order 121 and of the Hughes plane of order 121, under their full collineation groups. In PI, there are 13 orbits of Baer subplanes, all of which are desarguesian, and approximately 3000 orbits of Fano subplanes. In Sigma , there are 8 orbits of Baer subplanes, all of which are desarguesian, 2 orbits of subplanes of order 3, and at most 408; 075 distinct Fano subplanes. In addition to the above results, we also study the subplane structures of some non-desarguesian planes, such as the Hall plane of order 25, the Hughes planes of order 25 and 49, and the Figueora planes of order 27 and 125. A surprising discovery by L. Puccio and M. J. de Resmini was the existence of a plane of order 3 in the Hughes plane of order 25. We generalize this result, showing that there are subplanes of order 3 in the Hughes planes of order q2, where q is a prime power and q 5 (mod 6). Furthermore, we analyze the structure of the full collineation groups of certain Veblen- Wedderburn (VW) planes of orders 25, 49 and 121, and discuss how to recover the planes from their collineation groups.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1927609
- Subject Headings
- Projected planes, Combinatorial designs and configurations, Surfaces, Algebraic, Manifolds (Mathematics)
- Format
- Document (PDF)
- Title
- On the spectrum of positive operators.
- Creator
- Acharya, Cheban P., Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
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Spectral theory, mathematical system theory, evolution equations, differential and difference equations [electronic resource] : 21st International Workshop on Operator Theory and Applications, Berlin, July 2010.It is known that lattice homomorphisms and G-solvable positive operators on Banach lattices have cyclic peripheral spectrum (See [17]). In my thesis I prove that positive contractions whose spectral radius is 1 on Banach lattices with increasing norm have cyclic peripheral point...
Show moreSpectral theory, mathematical system theory, evolution equations, differential and difference equations [electronic resource] : 21st International Workshop on Operator Theory and Applications, Berlin, July 2010.It is known that lattice homomorphisms and G-solvable positive operators on Banach lattices have cyclic peripheral spectrum (See [17]). In my thesis I prove that positive contractions whose spectral radius is 1 on Banach lattices with increasing norm have cyclic peripheral point spectrum. I also prove that if the Banach lattice is a K B space satisfying the growth conditon and º is an eigenvalue of a positive contraction T such that [º] = 1, then 1 is also an eigenvalue of T as well as an eigenvalue of T¨, the dual of T. I also investigate the conditions on contraction operators on Hilbert lattices and AL-spaces which guanantee that 1 is an eigenvalue. As we know from [17], if T : E-E is a positive ideal irreducible operator on E such the r (T) = 1 is a pole of the resolvent R(º, T), then r (T) is simple pole with dimN (T -r(T)I) and ºper(T) is cyclic. Also all points of ºper(T) are simple poles of the resolvent R(º,T). SInce band irreducibility and º-order continuity do not imply ideal irreducibility [2], we prove the analogous results for band irreducible, º-order continuous operators.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3359288
- Subject Headings
- Operator theory, Evolution equations, Banach spaces, Linear topological spaces, Functional analysis
- Format
- Document (PDF)
- Title
- Permutation-based data compression.
- Creator
- Mihnea, Amalya, Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
The use of permutations in data compression is an aspect that is worthy of further exploration. The work that has been done in video compression based on permutations was primarily oriented towards lossless algorithms. The study of previous algorithms has led to a new algorithm that could be either lossless or lossy, for which the amount of compression and the quality of the output can be controlled. The lossless version of our algorithm performs close to lossy versions of H.264 and it...
Show moreThe use of permutations in data compression is an aspect that is worthy of further exploration. The work that has been done in video compression based on permutations was primarily oriented towards lossless algorithms. The study of previous algorithms has led to a new algorithm that could be either lossless or lossy, for which the amount of compression and the quality of the output can be controlled. The lossless version of our algorithm performs close to lossy versions of H.264 and it improves on them for the majority of the videos that we analyzed. Our algorithm could be used in situations where there is a need for lossless compression and the video sequences are part of a single scene, e.g., medical videos, where loss of information could be risky or expensive. Some results on permutations, which may be of independent interest, arose in developing this algorithm. We report on these as well.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3333054
- Subject Headings
- Data compression (Telecommunication), Combinatorics, Network architecture and design, Computer network architectures, Mathematical optimization
- Format
- Document (PDF)