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(1 - 7 of 7)
- Title
- AUTOMATED VISUAL DATABASE CREATION FOR A GROUND VEHICLE SIMULATOR.
- Creator
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Claudio, Pedro, Bauer, Christian, University of Central Florida
- Abstract / Description
-
This research focuses on extracting road models from stereo video sequences taken from a moving vehicle. The proposed method combines color histogram based segmentation, active contours (snakes) and morphological processing to extract road boundary coordinates for conversion into Matlab™ or Multigen OpenFlight™ compatible polygonal representations. Color segmentation uses an initial truth frame to develop a color probability density function (PDF) of the road versus the terrain....
Show moreThis research focuses on extracting road models from stereo video sequences taken from a moving vehicle. The proposed method combines color histogram based segmentation, active contours (snakes) and morphological processing to extract road boundary coordinates for conversion into Matlab™ or Multigen OpenFlight™ compatible polygonal representations. Color segmentation uses an initial truth frame to develop a color probability density function (PDF) of the road versus the terrain. Subsequent frames are segmented using a Maximum Apostiori Probability (MAP) criteria and the resulting templates are used to update the PDFs. Color segmentation worked well where there was minimal shadowing and occlusion by other cars. A snake algorithm was used to find the road edges which were converted to 3D coordinates using stereo disparity and vehicle position information. The resulting 3D road models were accurate to within 1 meter.
Show less - Date Issued
- 2006
- Identifier
- CFE0001326, ucf:46994
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001326
- Title
- MODELING AND PARTITIONING THE NUCLEOTIDE EVOLUTIONARY PROCESS FOR PHYLOGENETIC AND COMPARATIVE GENOMIC INFERENCE.
- Creator
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Castoe, Todd, Parkinson, Christopher, University of Central Florida
- Abstract / Description
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The transformation of genomic data into functionally relevant information about the composition of biological systems hinges critically on the field of computational genome biology, at the core of which lies comparative genomics. The aim of comparative genomics is to extract meaningful functional information from the differences and similarities observed across genomes of different organisms. We develop and test a novel framework for applying complex models of nucleotide evolution to solve...
Show moreThe transformation of genomic data into functionally relevant information about the composition of biological systems hinges critically on the field of computational genome biology, at the core of which lies comparative genomics. The aim of comparative genomics is to extract meaningful functional information from the differences and similarities observed across genomes of different organisms. We develop and test a novel framework for applying complex models of nucleotide evolution to solve phylogenetic and comparative genomic problems, and demonstrate that these techniques are crucial for accurate comparative evolutionary inferences. Additionally, we conduct an exploratory study using vertebrate mitochondrial genomes as a model to identify the reciprocal influences that genome structure, nucleotide evolution, and multi-level molecular function may have on one another. Collectively this work represents a significant and novel contribution to accurately modeling and characterizing patterns of nucleotide evolution, a contribution that enables the enhanced detection of patterns of genealogical relationships, selection, and function in comparative genomic datasets. Our work with entire mitochondrial genomes highlights a coordinated evolutionary shift that simultaneously altered genome architecture, replication, nucleotide evolution and molecular function (of proteins, RNAs, and the genome itself). Current research in computational biology, including the advances included in this dissertation, continue to close the gap that impedes the transformation of genomic data into powerful tools for the analysis and understanding of biological systems function.
Show less - Date Issued
- 2007
- Identifier
- CFE0001548, ucf:47138
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001548
- Title
- BIOGEOGRAPHY AND DIVERSIFICATION IN THE NEOTROPICS: TESTING MACROEVOLUTIONARY HYPOTHESES USING MOLECULAR PHYLOGENETIC DATA.
- Creator
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Daza Rojas, Juan Manuel, Parkinson, Christopher, University of Central Florida
- Abstract / Description
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Lineage diversification in the Neotropics is an interesting topic in evolutionary biology and one of the least understood. The complexity of the region precludes generalizations regarding the historical and evolutionary processes responsible for the observed high diversity. Here, I use molecular data to infer evolutionary relationships and test hypotheses of current taxonomy, species boundaries, speciation and biogeographic history in several lineages of Neotropical snakes. I comprehensively...
Show moreLineage diversification in the Neotropics is an interesting topic in evolutionary biology and one of the least understood. The complexity of the region precludes generalizations regarding the historical and evolutionary processes responsible for the observed high diversity. Here, I use molecular data to infer evolutionary relationships and test hypotheses of current taxonomy, species boundaries, speciation and biogeographic history in several lineages of Neotropical snakes. I comprehensively sampled a widely distributed Neotropical colubrid snake and Middle American pitvipers and combined my data with published sequences. Within the colubrid genus Leptodeira, mitochondrial and nuclear markers revealed a phylogeograhic structure that disagrees with the taxonomy based only on morphology. Instead, the phylogenetic structure corresponds to specific biogeographic regions within the Neotropics. Molecular evidence combined with explicit divergence time estimates reject the hypothesis that highland pitvipers in Middle America originated during the climatic changes during the Pleistocene. My data, instead, shows that pitviper diversification occurred mainly during the Miocene, a period of active orogenic activity. Using multiple lineages of Neotropical snakes in a single phylogenetic tree, I describe how the closure of the Isthmus of Panama generated several episodes of diversification as opposed to the Motagua-Polochic fault in Guatemala where a single vicariant event may have led to diversification of snakes with different ecological requirements. This finding has implications for future biogeographic studies in the region as explicit temporal information can be readily incorporated in molecular clock analyses. Bridging the gap between the traditional goals of historical biogeography (i.e., area relationships) with robust statistical methods, my research can be applied to multiple levels of the biological hierarchy (i.e., above species level), other regional systems and other sub-disciplines in biology such as medical research, evolutionary ecology, taxonomy and conservation.
Show less - Date Issued
- 2010
- Identifier
- CFE0003101, ucf:48328
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003101
- Title
- Biogeography and systematics of the Nerodia clarkii/Nerodia fasciata clade in Florida.
- Creator
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Territo, Gregory, Parkinson, Christopher, Hoffman, Eric, Fauth, John, University of Central Florida
- Abstract / Description
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Biogeography provides a window into the evolutionary history of populations, and helps explain the diversity and distribution of life through time. Viewed from a systematic perspective, biogeographic studies generate convincing arguments to explain the relationships among organisms and categorize them into useful taxonomies. When taxonomies do not reflect evolutionary histories, inaccurate representations of biodiversity confound future studies and conservation efforts. Two thamnophiine...
Show moreBiogeography provides a window into the evolutionary history of populations, and helps explain the diversity and distribution of life through time. Viewed from a systematic perspective, biogeographic studies generate convincing arguments to explain the relationships among organisms and categorize them into useful taxonomies. When taxonomies do not reflect evolutionary histories, inaccurate representations of biodiversity confound future studies and conservation efforts. Two thamnophiine snakes, Nerodia clarkii and Nerodia fasciata, harbor unique morphological and ecological adaptations that obscured natural groupings, leading to controversial taxonomic delimitations. Additionally, population declines documented in N. clarkii compressicauda and N. clarkii taeniata led managers to list N. clarkii taeniata as threatened in 1977. I generated a baseline for continued biogeographic and systematic study of the Nerodia clarkii/fasciata clade. I used mitochondrial DNA to build a parsimony-based haplotype network, infer the phylogenetic relationships between the two species and their thamnophiine relatives, and estimate the divergence times of major N. clarkii/fasciata clades. With these data, I tested biogeographic and systematic hypotheses about the origin and distribution of diversity in this clade. I used principal components analyses to summarize morphological data and discuss ecological observations in search of characters that may unite genetic or taxonomic units. The analyses revealed a peninsular and a panhandle clade in Florida that appeared to diverge as a result of Pleistocene glacial fluctuations. I found no support genetically, morphologically, or ecologically for the current taxonomy, indicating a need for range-wide research to generate revised nomenclature. My results do not support the protection status of N. clarkii taeniata.
Show less - Date Issued
- 2013
- Identifier
- CFE0004760, ucf:49764
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004760
- Title
- HABITAT USE AND SEASONAL ACTIVITY OF SELECTED SNAKES ON JOHN F. KENNEDY SPACE CENTER, FLORIDA.
- Creator
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Dyer, Karen, Stout, I. Jack, University of Central Florida
- Abstract / Description
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An intensive, replicated monthly sampling of snake communities inhabiting four habitat types was conducted at John F. Kennedy Space Center, Brevard County, Florida from November 2002 through October 2003. Thirteen species (580 individuals plus 74 recaptures) plus one hybrid were captured. The three most commonly captured species, Coluber constrictor, Thamnophis sirtalis, and Thamnophis sauritus, combined made up 85% of the sample. These three species were active during every month of the year...
Show moreAn intensive, replicated monthly sampling of snake communities inhabiting four habitat types was conducted at John F. Kennedy Space Center, Brevard County, Florida from November 2002 through October 2003. Thirteen species (580 individuals plus 74 recaptures) plus one hybrid were captured. The three most commonly captured species, Coluber constrictor, Thamnophis sirtalis, and Thamnophis sauritus, combined made up 85% of the sample. These three species were active during every month of the year, but showed modal activity patterns typical of Temperate Zone snakes. Monthly snake captures were correlated with monthly captures of potential prey species and with mean monthly temperature. Species richness in the four habitat types varied from nine to 12. Drift fences in ruderal habitats had the highest species richness, while fences in swales captured the greatest number of individuals. The most dissimilar habitat pair was scrub and swale, while the most similar pair was ruderal and hammock. Box traps proved more effective for targeting the largest snake species, while funnel and box traps were equally effective for targeting other species.
Show less - Date Issued
- 2004
- Identifier
- CFE0000237, ucf:46264
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000237
- Title
- ALTERNATIVE EPIGRAPHIC INTERPRETATIONS OF THE MAYA SNAKE EMBLEM GLYPH.
- Creator
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Savage, Christopher, Chase, Arlen, University of Central Florida
- Abstract / Description
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This thesis seeks to demonstrate that the Maya snake emblem glyph is associated with religious specialists, instead of geographic locations, as emblem glyphs are typically understood to be. The inscriptions and the media on which the snake emblem glyph occurs will be analyzed to determine the role or function of the "Lord of the Snake." Temporal and spatial data has also been collected to aid in understanding the enigmatic glyph. The snake emblem glyph has recently been identified as...
Show moreThis thesis seeks to demonstrate that the Maya snake emblem glyph is associated with religious specialists, instead of geographic locations, as emblem glyphs are typically understood to be. The inscriptions and the media on which the snake emblem glyph occurs will be analyzed to determine the role or function of the "Lord of the Snake." Temporal and spatial data has also been collected to aid in understanding the enigmatic glyph. The snake emblem glyph has recently been identified as originating from a broad area containing the sites of El Perú and La Corona in Guatemala, and Dzibanche, Mexico, a departure from the longstanding choice of Calakmul, Mexico. Unprovenanced snake emblem glyph texts have been cataloged under a "Site Q" designation („Q‟ for the Spanish word Que, meaning "which") by Peter Mathews. Site Q is thus not securely identified geographically, which confounds efforts to designate a particular site as the snake emblem glyph site. Other problems with the snake emblem glyph, such as its geographically wide dispersal, hint that it is not a title of a particular city or region. Yet another problem is "a proper fit" between the individuals listed on unprovenanced material and individuals named at sites associated with the snake emblem glyph. It is argued that the interpretation of the snake emblem glyph differs from how emblem glyphs are presently understood. Rather than representing a physical location, the snake emblem glyph represents a mythological place or "state," containing members who legitimize their lineage (association) through ritual events such as communication with supernaturals via the vision serpent. The specialists perform rituals, scatterings, are ballplayers, and witness events. They are rarely associated with accession, which by current interpretation is implicitly tied to emblem glyphs.
Show less - Date Issued
- 2007
- Identifier
- CFE0001842, ucf:47368
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001842
- Title
- Evolution and distribution of phenotypic diversity in the venom of Mojave Rattlesnakes (Crotalus scutulatus).
- Creator
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Strickland, Jason, Savage, Anna, Parkinson, Christopher, Hoffman, Eric, Rokyta, Darin, University of Central Florida
- Abstract / Description
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Intraspecific phenotype diversity allows for local adaption and the ability for species to respond to changing environmental conditions, enhancing survivability. Phenotypic variation could be stochastic, genetically based, and/or the result of different environmental conditions. Mojave Rattlesnakes, Crotalus scutulatus, are known to have high intraspecific venom variation, but the geographic extent of the variation and factors influencing venom evolution are poorly understood. Three primary...
Show moreIntraspecific phenotype diversity allows for local adaption and the ability for species to respond to changing environmental conditions, enhancing survivability. Phenotypic variation could be stochastic, genetically based, and/or the result of different environmental conditions. Mojave Rattlesnakes, Crotalus scutulatus, are known to have high intraspecific venom variation, but the geographic extent of the variation and factors influencing venom evolution are poorly understood. Three primary venom types have been described in this species based on the presence (Type A) or absence (Type B) of a neurotoxic phospholipase A2 called Mojave toxin and an inverse relationship with the presence of snake venom metalloproteinases (SVMPs). Individuals that contain both Mojave toxin and SVMPs, although rare, are the third, and designated Type A + B. I sought to describe the proteomic and transcriptomic venom diversity of C. scutulatus across its range and test whether diversity was correlated with genetic or environmental differences. This study includes the highest geographic sampling of Mojave Rattlesnakes and includes the most venom-gland transcriptomes known for one species. Of the four mitochondrial lineages known, only one was monophyletic for venom type. Environmental variables poorly correlated with the phenotypes. Variability in toxin and toxin family composition of venom transcriptomes was largely due to differences in transcript expression. Four of 19 toxin families identified in C. scutulatus account for the majority of differences in toxin number and expression variation. I was able to determine that the toxins primarily responsible for venom types are inherited in a Mendelian fashion and that toxin expression is additive when comparing heterozygotes and homozygotes. Using the genetics to define venom type is more informative and the Type A + B phenotype is not unique, but rather heterozygous for the PLA2 and/or SVMP alleles. Intraspecific venom variation in C. scutulatus highlights the need for fine scale ecological and natural history information to understand how phenotypic diversity is generated and maintained geographically through time.
Show less - Date Issued
- 2018
- Identifier
- CFE0007252, ucf:52198
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007252
