A espécie Bothrops atrox é responsável por grande parte dos acidentes no estado do Amazonas. No entanto, ainda são poucos os estudos sobre as toxinas que compõem o veneno dessa serpente, os mecanismos envolvidos na sintomatologia dos acidentes, bem como de formas de inibição. Os soros antiveneno utilizados atualmente com o objetivo de neutralizar as atividades sistêmicas e locais dos venenos mostraram reatividade cruzada entre componentes dos venenos de serpentes do gênero Bofhrops (MOURA DA SILVA et al., 1990). No entanto alguns componentes do veneno não apresentaram essa reatividade (SILES-VILARROEL et al.., 1974), mostrando a existência de toxinas espécie específicas.Os venenos de serpentes estão sujeitos a grandes variações induzidas por diversos aspectos ontogenéticos e influencia do habitat. Assim, essas variações podem gerar toxinas espécie específicas cujos mecanismos de ação ainda são desconhecidos e que os anticorpos presentes nos antivenenos disponíveis não sejam capazes de reconhecer e neutralizar eficientemente. O gênero Bothrops possui espécies extremamente variáveis, algumas de difícil classificação taxonõmica, e novas espécies têm sido descobertas recentemente. Como contribuição para o acúmulo de informações a respeito das diferentes composições do veneno do gênero Bothrops, e para o conhecimento de toxinas já isoladas e as ainda não isoladas na espécie tipo Bothrops atrox, foi construída uma biblioteca de cDNA da glândula de veneno.Os dados obtidos são importantes para a elaboração de um painel da expressão gênica dessa espécie e permitirá a identificação de toxinas que podem ser comuns ou não ao veneno de outras espécies do gênero. Aliado a isso, esses dados permitirão a correlação com o estudo proteõmico, e possivelmente fornecerão subsídios para a melhoria da terapêutica empregada no tratamento dos casos envenamento na região. / The species Bothrops atrox is responsible for most accidents in state of Amazonas. However, there are few studies on toxins that make up the venom of this snake, mechanisms involved in symptomatology of accidents, as well as inhibition forms. Sera antivenom currently used in order to neutralize the systemic and local activities of the venoms showed cross-reactivity between components of the venom of Bothrops (MOURA DA SILVA et al., 1990). However some components of the venom showed no reactivity (SILES-VILARROEL et al., 1974), indicating the existence of species-specific toxins. Snake venoms are subject to large variations induced by several aspects and influences of ontogenetic habitat. Thus, these variations can produce toxins whose mechanisms of species-specific action are still unknown and antibodies present in available antivenoms maybe not are capable to recognize and neutralize some toxins efficiently. Bothrops species have highly variable, some of difficult taxonomic classification and new species have been discovered recently. As a contribution to gain of information about of different compositions of Bothrops venom and to knowledge of toxins not yet isolated and the isolated in Bothrops atrox type species we constructed a venom gland cDNA library . The data obtained are important for the development of gene expression panel of this species and enable the identification of toxins common or not in the venom of other species. These data will allow correlation with the proteomic study, and possibly provide input for improving the therapeutic used in the treatment of accidents cases in the region.

This thesis deals with articulated robots for special applications for confined spaces. Introduction work includes the distribution and development in the field of handling technology. It also deals with the handlers chain structure. Following the described types of articulated robot kinematic model was developed and subsequently implemented the 3D design in SolidWorks. The conclusion is drawn visualizations made-handling arm.

The primary pattern of embryonic nutrition for squamate reptiles is lecithotrophy; with few exceptions, all squamate embryos mobilize nutrients from yolk. The evolution of viviparity presents an opportunity for an additional source of embryonic nutrition through delivery of uterine secretions, or placentotrophy. This pattern of embryonic nutrition is thought to evolve through placental supplementation of lecithotrophy, followed by increasing dependence on placentotrophy. This review analyzes the relationship between reproductive mode and pattern of embryonic nutrition in three lecithotrophic viviparous species, and oviparous counterparts, for concordance with a current model for the evolution of viviparity and placentation. The assumptions of the model, that nutrients for oviparous embryos are mobilized from yolk, and that this source is not disrupted in the transition to viviparity, are supported for most nutrients. In contrast, calcium, an essential nutrient for embryonic development, is mobilized from both yolk and eggshell by oviparous embryos and reduction of eggshell calcium is correlated with viviparity. If embryonic fitness is compromised by disruption of a primary source of calcium, selection may not favor evolution of viviparity, yet viviparity has arisen independently in numerous squamate lineages. Studies of fetal nutrition in reproductively bimodal species suggest a resolution to this paradox. If uterine calcium secretion occurs during prolonged intrauterine egg retention, calcium placentotrophy evolves prior to viviparity as a replacement for eggshell calcium and embryonic nutrition will not be compromised. This hypothesis is integrated into the current model for evolution of viviparity and placentation to address the unique attributes of calcium nutrition. The sequence of events requires a shift in timing of uterine calcium secretion and the embryonic mechanism of calcium retrieval to be responsive to calcium availability. Regulation of uterine calcium secretion and the mechanism of embryonic uptake of calcium are important elements to understanding evolution of viviparity and placentation.

The primary pattern of embryonic nutrition for squamate reptiles is lecithotrophy; with few exceptions, all squamate embryos mobilize nutrients from yolk. The evolution of viviparity presents an opportunity for an additional source of embryonic nutrition through delivery of uterine secretions, or placentotrophy. This pattern of embryonic nutrition is thought to evolve through placental supplementation of lecithotrophy, followed by increasing dependence on placentotrophy. This review analyzes the relationship between reproductive mode and pattern of embryonic nutrition in three lecithotrophic viviparous species, and oviparous counterparts, for concordance with a current model for the evolution of viviparity and placentation. The assumptions of the model, that nutrients for oviparous embryos are mobilized from yolk, and that this source is not disrupted in the transition to viviparity, are supported for most nutrients. In contrast, calcium, an essential nutrient for embryonic development, is mobilized from both yolk and eggshell by oviparous embryos and reduction of eggshell calcium is correlated with viviparity. If embryonic fitness is compromised by disruption of a primary source of calcium, selection may not favor evolution of viviparity, yet viviparity has arisen independently in numerous squamate lineages. Studies of fetal nutrition in reproductively bimodal species suggest a resolution to this paradox. If uterine calcium secretion occurs during prolonged intrauterine egg retention, calcium placentotrophy evolves prior to viviparity as a replacement for eggshell calcium and embryonic nutrition will not be compromised. This hypothesis is integrated into the current model for evolution of viviparity and placentation to address the unique attributes of calcium nutrition. The sequence of events requires a shift in timing of uterine calcium secretion and the embryonic mechanism of calcium retrieval to be responsive to calcium availability. Regulation of uterine calcium secretion and the mechanism of embryonic uptake of calcium are important elements to understanding evolution of viviparity and placentation.

Snake vertebrae are common throughout the Cenozoic fossil record, but identification of isolated vertebrae often proves difficult due to inter- and intra-columnar variability. Most fossil identifications are based on comparisons with disarticulated modern specimens, with a focus on mid-trunk vertebrae. One focus of this study was to determine the necessity of identifying a true mid-trunk vertebra prior to identification and to develop a method of locating the columnar position of an isolated vertebra for both modern and fossil identifications. Colubrid genera Farancia and Heterodon were chosen for the analysis because they share distinct morphological similarities, articulated modern specimens were available, and fossil species in these genera need to be reassessed. Every third pre-cloacal vertebra was selected from each specimen to undergo geometric morphometric analysis on its anterior face. Relative warp analyses detailed the inter-columnar variation of each specimen and found that the only significant difference in the column was between the anterior most vertebrae, which are already identifiable, and the remainder of the pre-cloacal vertebrae. Despite concern, the convention of using mid-trunk vertebrae for identification may prove accurate for these genera. Due to Farancia and Heterodon’s vertebral similarities, a discriminant function analysis was utilized to distinguish the two genera from one another. To evaluate this method’s utility in paleontology, vertebrae of two extinct species, Heterodon brevis and Paleofarancia brevispinosus, will undergo identical morphometric and discriminant analyses. This study also emphasizes the need for more modern snake skeletons in collections and the necessity of stringing the vertebral column prior to disarticulation.

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. 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.

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 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.

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 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.

Grotesque elements in literature are often negatively viewed as an author’s attempt to simply twist reality in an effort to shock or entertain the reader. However, as I explain in my critical introduction, this view disregards the potential of the grotesque. It often has a specific purpose within a plot. It reveals things about characters that would not otherwise be exposed. I discuss this function of the grotesque in the works of Flannery O’Connor, Edgar Allan Poe, Truman Capote, and Brad Watson, and then show how these authors’ uses of the grotesque have influenced my own writing. In my collection of short fiction, each story contains grotesque elements that reveal and emphasize my characters’ hopes and fears.

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