Dissertations / Theses on the topic 'Snakes'

On three days in March each year, the sleepy little town of Sweetwater, Texas transforms into the rattlesnake capital of the world. Snake hunters and curious tourists converge on the town of 12,000 for the Annual Sweetwater Rattlesnake Roundup. On the outside of the Nolan County Coliseum, the smell of funnel cakes and hot-dogs fills the air as vendors sell snacks and souvenirs. However the real action is inside where snakes collected from all over the state lay in piles by the thousands, waiting to be sexed, milked and ultimately killed. Through interviews and observational footage, "Snakes Alive!" explores the Sweetwater Rattlesnake Roundup, those that participate in the event, and the elements that make it an unabashed West Texas tradition.

This thesis describes the isolation and molecular identification of a novel paramyxovirus found in Australian snakes. The virus is named Sunshine virus after the geographical origin of the first isolate: the Sunshine Coast of Queensland, Australia. For decades, Australian veterinarians have been presented with snakes displaying neurorespiratory signs. The clinical signs, pathological findings and the results of overseas diagnostic testing, have suggested that at least some of these snakes were infected with paramyxoviruses, most likely ferlaviruses. Australian veterinarians provided 463 samples to be screened for the presence of viruses and nine were found from five snakes from two collections. For all isolates, cytopathic effects consisted of extensive syncytial cell formation with minimal cell lysis. Further characterisation was performed on one of these isolates, BHP1-Lung (from a lung homogenate of a black-headed python [BHP], Aspidites melanocephalus with mild respiratory signs and stomatitis). Testing this isolate for haemagglutinating and neuraminidase activity provided equivocal results. The virus could not be found by electron microscopy. Polymerase chain reaction to detect a broad range of paramyxoviruses, reoviruses, adenoviruses and herpesviruses was also non-contributory. Through the use of high-throughput sequencing, BHP1-Lung was identified as a novel paramyxovirus. Phylogenetic analysis of the nucleoprotein (N), matrix (M), fusion (F) and polymerase (L) proteins clustered this virus within the family Paramyxoviridae but outside of both subfamilies. Primers were designed that could detect Sunshine virus which enabled clinical data that is associated with Sunshine virus infection to be described. Clinical signs are typically non-specific (e.g. regurgitation, lethargy, inappetence) and/or can be localised to the neurological and/or respiratory systems. Gross pathology is usually unremarkable. Histopathological findings consist primarily of white matter spongiosis and gliosis of the hindbrain with a mild bronchointerstitial pneumonia.

When Sidestreets Become Snakes is a collection of free verse poetry in which the speaker explores her family relationships and traumas through the use of various metaphors, personas, and imagery to illustrate significant moments in her life. Split into three sections, this collection follows the speaker through her childhood traumas and experiences, adolescent questioning of those experiences and relationships, and finally, her life as an adult in which she comes to accept the past, her family, and herself.

Pathogenic fungi are increasingly associated with epidemics in wildlife populations and represent a significant threat to global biodiversity. Snake fungal disease is an emerging disease caused by the fungus, Ophidiomyces ophiodiicola, and appears to be widespread in the eastern United States. Yet an evaluation of field diagnostics, and an understanding of the population-level consequences of the disease, are lacking. First, I evaluated the use of clinical signs to predict the presence of O. ophiodiicola across season and snake habitat affiliation (aquatic or terrestrial) and I compared two sampling methods to see if collection method impacts PCR result. Overall, snakes with clinical signs had a higher probability of testing positive regardless of season or habitat association. However, terrestrial snakes had a lower overall probability of testing positive for O. ophiodiicola compared to aquatic snakes. I found no significant difference between sampling methods. Second, I used Passive Integrated Transponder (PIT) telemetry, and multistate capture-mark-recapture modelling to determine if SFD affects the short-term survival, movement, and behavior of wild snakes. I found no difference in short-term survival for snakes with SFD. Snakes with SFD spend more time surface-active and have lower permanent emigration and temporary immigration rates than snakes without SFD.

Made available in DSpace on 2014-06-11T19:23:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T19:09:22Z : No. of bitstreams: 1 oliveira_rms_me_prud.pdf: 2936252 bytes, checksum: 250c550ac7923d26a59bbd1cb2bb5287 (MD5)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>A obtenção de informações a partir da extração de feições em fotos aéreas e imagens de satélite é um dos principais objetivos da nova tecnologia de automação em Fotogrametria Digital. Este trabalho propõe a extração de rodovias, e a conexão de segmentos de rodovias extraidos por outros extratores de feições, utilizando modelos de contorno ativo ou snakes. Snakes foi introduzido há quase duas décadas e consiste em uma curva representada parametricamente e controlada por injunções fotométricas e geométricas: fotométricas, chamadas de força da imagem que atraem a curva snakes para a feição a ser extraída (rodovia); geométricas, geradas pelas forças internas que controlam a forma da curva snakes garantindo sua suavidade. Por ser um método de extração semi-automático, inicialmente o operador deve descrever a rodovia de maneira grosseira utilizando no mínimo seis pontos sementes. A partir desta posição inicial a curva snakes evolui a cada iteração fazendo com que a mesma se posicione sobre a borda da rodovia (feição a ser extraída) onde sua energia é minimizada. O método snakes foi implementado em linguagem C e testado na extração e conexão de segmentos de rodovia em imagens de alta (pixels menores 0.7m), média (pixels entre 0.7m e 2.0m) e baixa (pixels maiores 2.0m) resolução, mostrando-se bastante eficiente em todos os casos, mesmo na presença de obstáculos que perturbam o perfeito delineamento da rodovia. Através da extração de bordas de rodovia, em imagens de alta e média resolução, foi gerado um eixo interpolado e comparado com o eixo de referência utilizado para avaliação. Utilizando avaliações visuais e numéricas foi possível comprovar a boa acuracia do processo de extração e conexão de segmentos utilizando snakes.<br>Obtaining information from the extraction of aspects from aerial photographs and satellite images is one of the main purposes of the new technology in Digital Photogrammetry. This study proposes extracting roads and linking the segments of the extracted roads by means of other extractors of aspects, by using models of active contour, or snakes. Snakes was introduced almost two decades ago, and it consists in a parametrically represented curve, controlled by photometric and geometric injunctions: photometric injunctions, called image power, that attract the snakes curve for the aspect to be extracted (road); geometric injunctions, generated by internal powers that control the shape of the snakes curve, thus insuring its smoothness. As it is a semi-automatic extraction process, the operator shall initially describe the road roughly, using at least six seed points. From this initial position, the snakes curve evolves at each iteration, placing itself over the road edge (aspect to be extracted), where its power is minimized. The snakes method was implemented in language C and tested in the extraction and link of road segments in images of high resolution (pixels lower than 0.7m), medium resolution (pixels between 0.7m and 2.0m) and low resolution (pixels higher than 2.0m), and it turned out to be very efficient in both cases, even in the presence of obstacles that disturb the perfect road outlining. With the extraction of road edges in high and medium resolution images, one interpolated axis was generated, and it was compared to the reference axis used in the evaluation. By using visual and numerical evaluations, it was possible to prove the accuracy provided by the process of extraction and link of segments that uses the snakes method.

Orientador: Aluir Porfírio dal Poz<br>Resumo: A obtenção de informações a partir da extração de feições em fotos aéreas e imagens de satélite é um dos principais objetivos da nova tecnologia de automação em Fotogrametria Digital. Este trabalho propõe a extração de rodovias, e a conexão de segmentos de rodovias extraidos por outros extratores de feições, utilizando modelos de contorno ativo ou snakes. Snakes foi introduzido há quase duas décadas e consiste em uma curva representada parametricamente e controlada por injunções fotométricas e geométricas: fotométricas, chamadas de força da imagem que atraem a curva snakes para a feição a ser extraída (rodovia); geométricas, geradas pelas forças internas que controlam a forma da curva snakes garantindo sua suavidade. Por ser um método de extração semi-automático, inicialmente o operador deve descrever a rodovia de maneira grosseira utilizando no mínimo seis pontos sementes. A partir desta posição inicial a curva snakes evolui a cada iteração fazendo com que a mesma se posicione sobre a borda da rodovia (feição a ser extraída) onde sua energia é minimizada. O método snakes foi implementado em linguagem C e testado na extração e conexão de segmentos de rodovia em imagens de alta (pixels menores 0.7m), média (pixels entre 0.7m e 2.0m) e baixa (pixels maiores 2.0m) resolução, mostrando-se bastante eficiente em todos os casos, mesmo na presença de obstáculos que perturbam o perfeito delineamento da rodovia. Através da extração de bordas de rodovia, em imagens de alta e média resolução, foi gerado um eixo interpolado e comparado com o eixo de referência utilizado para avaliação. Utilizando avaliações visuais e numéricas foi possível comprovar a boa acuracia do processo de extração e conexão de segmentos utilizando snakes.<br>Abstract: Obtaining information from the extraction of aspects from aerial photographs and satellite images is one of the main purposes of the new technology in Digital Photogrammetry. This study proposes extracting roads and linking the segments of the extracted roads by means of other extractors of aspects, by using models of active contour, or snakes. Snakes was introduced almost two decades ago, and it consists in a parametrically represented curve, controlled by photometric and geometric injunctions: photometric injunctions, called image power, that attract the snakes curve for the aspect to be extracted (road); geometric injunctions, generated by internal powers that control the shape of the snakes curve, thus insuring its smoothness. As it is a semi-automatic extraction process, the operator shall initially describe the road roughly, using at least six seed points. From this initial position, the snakes curve evolves at each iteration, placing itself over the road edge (aspect to be extracted), where its power is minimized. The snakes method was implemented in language C and tested in the extraction and link of road segments in images of high resolution (pixels lower than 0.7m), medium resolution (pixels between 0.7m and 2.0m) and low resolution (pixels higher than 2.0m), and it turned out to be very efficient in both cases, even in the presence of obstacles that disturb the perfect road outlining. With the extraction of road edges in high and medium resolution images, one interpolated axis was generated, and it was compared to the reference axis used in the evaluation. By using visual and numerical evaluations, it was possible to prove the accuracy provided by the process of extraction and link of segments that uses the snakes method.<br>Mestre

Snakes represent an impressive evolutionary radiation of over 3,500 widely-distributed species, categorized into 515 genera, encompassing a diverse range of morphologies and ecologies. This diversity is likely attributable to their distinctive morphology, which has allowed them to populate a wide range of habitat types within most major ecosystems. In my first chapter, I provide the largest-yet estimate of the snake tree of life using maximum likelihood on a supermatrix of 1745 taxa (1652 snake species + 7 outgroup taxa) and 9,523 base pairs from 10 loci (5 nuclear, 5 mitochondrial), including previously unsequenced genera (2) and species (61). I then use this phylogeny to test hypotheses regarding heterogeneity in diversification rates and how this shaped overall patterns of snake diversity in Chapter 2. I also used the species-level phylogeny to test the evolution of habitat use in snakes, morphological variation, and whether distantly-related species exhibit morphological convergence in Chapter 3. Finally, in Chapter 4 I investigate how prehensile tails effect striking performance in arboreal snakes.

The increasing popularity of snakes and lizards as pets has led to an increasing demand of specialised veterinary duties in these animals. Diagnostic imaging is often a fundamental step of the clinical investigation. The interpretation of diagnostic images is complex and requires a broad knowledge of anatomy, physiology and pathology of the species object of the clinical investigation. Moreover, in order to achieve a correct diagnosis, the comparison between normal and abnormal diagnostic images, for all the diagnostic imaging modalities, is mandatory. In this PhD thesis the diagnostic imaging features of some snake and lizard species are described. The aim of all the works presented is to provide some normal atlases matching the normal gross and cross-sectional anatomy with the normal radiographic, ultrasonographic, CT features of some of the most popular pet lizard and snake specie. In Chapter I a review of literature regarding snakes and lizards is presented. The aim of this chapter is to review the most commonly used diagnostic imaging modalities as well as to make an updated collection of the available international references describing the normal and pathological imaging features in snakes and lizards. Most of papers describing radiography, ultrasonography, computed tomography, magnetic resonance imaging and other imaging modalities have been collected in order to overcome the lack of a unique reference regarding diagnostic imaging in snakes and lizards. The scientific aims and the outline of this thesis are presented in Chapter II. The general aim of this PhD thesis is to provide some useful anatomical and diagnostic imaging references in snakes and lizards. The first part of this work (Chapters III and IV) is focused on the description of the normal radiographic and computed tomographic features of the head of some snakes and lizards species. The second part (Chapters V to VII) is focused on the diagnostic imaging of the coelomic cavity; the description of the normal contrast enhanced computed tomographic features of the coelomic cavity of some lizards, the normal ultrasonographic features of the coelomic cavity of some snake species and the normal upper gastro-intestinal examination in the ball python are presented. In Chapter III the normal stratigraphic and cross sectional anatomy is matched with the normal radiographic and computed tomographic features of the head of the Boa constrictor. 4 boa constrictor’s cadavers head where used in this study. Radiographs of the head were taken in LL and DV projections using a high detail screen-film combination. CT scans scans of the head where performed in a CC and a LL direction with a slice thickness of 1,5mm and displayed in a bone window. 2 heads where dissected following a stratigraphic approach and 2 heads frozen for 24h (-20°C) and then sectioned into 3mm slices respecting the imaging protocol. All anatomical structures have been identified and labelled with the aid of available literature in the anatomical images and then matched on the corresponding radiographic and computed tomographic images. Radiographic and CT images provided a high detail for the visualisation of bony structures; soft tissues were not easily identified on radiographic and CT images. In Chapter IV the normal radiographic and contrast enhanced computed tomographic features of the head of the green iguana, common tegu and bearded dragon are described. The study included 4 cadavers for each considered species and 6 adult green iguanas, 4 tegus, 3 bearded dragons. Prior to the beginning of the radiographic and computed tomographic studies 2 cadavers were dissected following a stratigraphic approach and 2 cadavers were cross-sectioned for each species. Anatomical studies were performed following the same approach described in Chapter III. Both the radiographic and the computed tomographic studies were performed only in live animals. Radiographic studies included a LL and a DV projection. Pre- and post- contrast computed tomographic studies of the head were performed in a CC direction. CT images were displayed in both bone and soft tissue windows. Individual anatomical structures were first recognised and labelled on the anatomic images and then matched on radiographs and CT images. Radiographic studies provided a good detail both of the soft tissues (especially in the green iguana) and of the bony structures. CT images provided an excellent detail of the bony structures in all the considered species. The soft tissues were clearly outlined only in the green iguana. In the common tegu and the bearded dragon only the eyes were clearly outlined from the remaining soft tissues. In Chapter V the normal contrast enhanced computed tomographic features of the coelomic cavity of the green iguana, black and white tegu and the bearded dragon are described. 4 cadavers and 4 live animals for each considered species were object of this study. The cadavers were frozen for 24 hours and then cross sectioned at 5mm intervals. The slices have been cleaned with water and photographed on both sides. In order to reduce the duration of the procedure only contrast enhanced CT scans have been performed. The CT scans have been performed in a CC direction. The CT scans have been displayed in a soft tissue and, when appropriate, in a lung window. Individual organs have been recognised and labelled on the anatomical images and then matched on the corresponding CT images. Most of the coelomic organs have been identified in all the considered species. Results provide an atlas of the normal cross sectional and CT features of the coelomic cavity of lizards. In Chapter VI the normal ultrasonographic features of the coelomic cavity of the Boa constrictor, Python molurus, Python curtus and Python regius are described. Moreover, normal reference ultrasonographic measurements of the scent glans, the colonic, gastric and pyloric wall thickness are reported. 46 live snakes (16 Python regius, 10 Python molurus, 12 Python curtus and 8 Boa constrictor) and 23 cadavers (6 Python regius, 4 Python molurus, 10 Python curtus, 3 Boa constrictor) where object of this study. Anatomical studies where performed prior to the beginning of the ultrasonographic studies in order to characterise the normal anatomical features of the above mentioned species. In previous ultrasonographic studies of the coelomic cavity of the Boa constrictor studies a ventral approach on sedated animals was proposed. We have decided to use a lateral approach on unsedated animals. Although, especially in larger animals, the shadowing effect produced by the ribs was evident in some images, most of the coelomic organs (scent glands, hemipenes, cloaca, ureters, colon, small intestine, pylorus, stomach, pancreas, liver, gallbladder and oesophagus) have been recognised. The rate of ultrasonographic recognition of individual organs is reported. Results provide a description of the normal ultrasonographic features of coelomic cavity of boid snakes along with a series of tables matching the gross and cross sectional anatomy with corresponding normal ultrasonographic images. In Chapter VII the technique and the normal features of upper gastro-intestinal examination in ball pythons are described. 10 ball python's cadavers have been dissected and cross sectioned prior to the the beginning of the study in order to characterise the normal features of the intestine in this species.18 healthy ball pythons where object of this study. All animals where not fed for at least 7 days before the beginning of the study. The animals have been divided into three groups (A, B, C). Contrast medium (barium sulphate) at the dose of 25 ml/kg has been administered through an esophageal probe at an increasing concentration (25%, 35% and 45 wt/vol) to three groups. An initial animal (Group A , 25% wt/vol) was used to verify the feasibility and establish a time course for the procedure. Imaging quality was evaluated by 3 investigators who assigned a grading score on the basis of predetermined criteria. Results of present study revealed that the 35% wt/vol concentration of contrast medium provided the best imaging quality. Moreover, three pattern of distribution of the contrast medium in the small intestine, independent from the concentration, have been described.<br>Negli ultimi anni ofidi e sauri sono diventati sempre più diffusi come animali da compagnia. Questa crescente diffusione ha comportato un aumento della richiesta di servizi veterinari specializzati in questi animali. L’imaging diagnostico spesso è una parte fondamentale dell’indagine clinica. La corretta interpretazione delle immagini diagnostiche implica una conoscenza approfondita dell’anatomia, fisiologia e patologia della specie oggetto dell’indagine clinica. Il confronto tra immagini normali e immagini patologiche spesso è di vitale importanza per una corretta interpretazione delle immagini diagnostiche. Lo scopo di questa tesi di dottorato è quella di fornire degli atlanti che mettano in relazione l’anatomia normale e per sezioni con le corrispondenti immagini radiografiche, tomografiche e ecografiche di alcune delle specie più popolari di ofidi e sauri. Il Capitolo I è riportata una revisione della letteratura corrente sull’imaging in ofidi e sauri. Al momento manca un riferimento univoco su questo argomento e la letteratura presente è spesso frammentaria a volte difficile da reperire. L’obiettivo di questo capitolo, quindi, è quello di fare il punto sullo stato dell’arte della diagnostica per immagini in ofidi e sauri. Molti articoli internazionali riguardanti la radiologia, l’ecografia, la tomografia computerizzata, la risonanza magnetica e altre tecniche di imaging sono stati citati in modo da creare un riferimento utile ai clinici che si occupano di animali esotici. Nel Capitolo II vengono presentati gli obiettivi scientifici e la struttura di questa tesi. L’obiettivo generale è quello di fornire una descrizione dell’anatomia e dell’imaging normale in ofidi e sauri. La prima parte (Capitoli III e IV) è incentrata sul confronto tra la l’anatomia normale e per sezioni della testa alcune specie di ofidi e sauri con i normali aspetti radiografici e tomografici. La seconda parte (Capitoli dal V al VII) è incentrata sull’imaging della cavità celomatica. In questi capitoli sono descritti: gli aspetti normali valutati in tomografia computerizzata della cavità celomatica di alcune specie di sauri, l’ecografia normale in alcune specie di ofidi e il Nel Capitolo III sono descritti i normali aspetti anatomici, radiografici e tomografici della testa del Boa constrictor. Per questo studio sono stati impiegate le teste di 4 cadaveri di Boa constrictor. Utilizzando una combinazione pellicola-casetta ad alta definizione sono state ottenute proiezioni latero-laterali e dorso-ventrali di tutte le teste. L’esame tomografico è stato eseguito in direzione cranio-caudale e latero-laterale con uno spessore di fetta di 1,5mm. Le immagini sono state visualizzate in una finestra da osso. 2 teste sono state dissezionate con un approccio stratigrafico. 2 teste invece sono state congelate per 24 ore a -20°C e poi sezionate in fette di 3mm rispettando il protocollo utilizzato in tomografia computerizzata. Le strutture anatomiche sono state identificate nelle immagini anatomiche e poi accoppiate con le corrispondenti immagini radiografiche e tomografiche. I tessuti ossei sono ben definiti sia nelle immagini radiografiche che tomografiche; i tessuti molli risultano poco definiti in entrambe. Nel Capitolo IV l’anatomia stratigrafica e per sezioni della testa dell’iguana, del tegu e del drago barbuto vengono messi in relazione con il loro normale aspetto radiografico e tomografico. Per realizzare questo studio sono stati usati 4 cadaveri per specie e 6 iguane, 4 tegu e 3 draghi barbuti adulti. Prima di iniziare gli studi di imaging 2 cadaveri per specie sono stati dissezionati con un approccio stratigrafico e 2 sono stati sezionati. Gli studi anatomici sono stati eseguiti con la stessa metodica riportata nel Capitolo III. Gli studi radiografici e tomografici sono stati eseguiti solo sugli animali vivi. Le radiografie sono stata scattate in proiezione latero-laterale e dorso-ventrale. Le scansioni tomografiche sono state effettuate pre e post contrasto scansionando gli animali in direzione cranio-caudale. Le immagini tomografiche sono state quindi visualizzate sia in finestra da tessuti molli che da osso. Le strutture anatomiche sono state individuate prima nelle immagini anatomiche e poi correlate con le corrispondenti immagini radiografiche e tomografiche. Gli studi radiografici hanno permesso di visualizzare in maniera ottimale sia i tessuti duri che i tessuti molli (specialmente nell’iguana). Negli studi tomografici le strutture ossee sono state visualizzate in modo ottimale in tutte le specie. I tessuti molli sono chiaramente delineati solo nell’iguana; nel tegu e nel drago barbuto si riescono a distinguere chiaramente solo gli occhi. Nel Capitolo V i normali aspetti anatomici della cavità celomatica dell’iguana verde, del tegu bianco e nero e del drago barbuto sono messi in relazione con i normali aspetti tomografici di queste specie. Per questo studio sono stati usati 4 cadaveri e 4 animali vivi per specie. I cadaveri sono stati congelati per 24 ore e poi sezionati a intervalli di 5mm. Le fette così ottenute sono state lavate da entrambi i lati e poi fotografate. Per ridurre la durata delle procedure diagnostiche sono state effettuate solo procedure post-contrasto. Le scansioni tomografiche sono state effettuate in direzione cranio-caudale. Le immagini tomografiche sono state visualizzate in finestra da tessuti molli e da polmoni. La maggior parte degli organi celomatici sono stati individuati sia nelle immagini anatomiche che nelle immagini tomografiche. Il risultato di questo lavoro è un atlante degli aspetti anatomici e tomografici normali della cavità celomatica di queste specie di sauri. Nel Capitolo VI vengono descritti gli aspetti ultrasonografici normali della cavità celomatica del Boa constrictor, Python molurus, Python curtus e Python regius. Inoltre vengono fornite le misure ecografiche di riferimento delle scent glands e delle mucose gastica, pilorica e del colon nelle suddette specie. Per questo lavoro sono stati utilizzati 46 serpenti vivi (16 Python regius, 10 Python molurus, 12 Python curtus and 8 Boa constrictor) and 23 cadaveri (6 Python regius, 4 Python molurus, 10 Python curtus, 3 Boa constrictor). Gli studi anatomici sono stati effettuati prima di iniziare gli studi ecografici in modo da caratterizzare i normali aspetti anatomici di queste specie. In un lavoro precedente, nel quale vengono descritti i normali aspetti ecografici del Boa constrictor, viene proposto un approccio ventrale al paziente. In questo studio proponiamo un approccio laterale. In alcune immagini ecografiche i coni d’ombra prodotti dalle coste di questi animali, specialmente nei soggetti di maggiori dimensioni, degradavano leggermente la qualità dell’esame. Nonostante ciò è stato possibile riconoscere la maggior parte degli organi celomatici (scent glands, emipeni, cloaca, ureteri, colon, piccolo e grosso intestino, piloro, stomaco, pancreas, fegato, cistifellea ed esofago). Il numero di animali nei quali i singoli organi sono stati visualizzati è stato riportato. Questo lavoro ha prodotto una descrizione completa degli aspetti ecografici normali in alcune specie di boidi oltre a una serie di tavole che mettono in relazione l’anatomia normale e per sezioni con le corrispondenti immagini ecografiche. Nel Capitolo VII è riportata la tecnica e gli aspetti normali dello studio radiografico dell’esofago, stomaco e piccolo intestino nel Python regius. Per caratterizzare l’aspetto normale del piccolo intestino di questa specie i cadaveri di 10 Python regius sono stati dissezionati prima dei iniziare procedure diagnostiche. Per questo lavoro sono stati utilizzati 18 Python regius. Tutti gli animali utilizzati non sono stati nutriti nella settimana precedente lo studio. Gli animali sono stati divisi in 3 gruppi (A, B, C). Il mezzo di contrasto (bario solfato) è stato somministrato alla dose di 25ml/kg tramite una sonda esofagea a concentrazione crescente (25%, 35%, 45% p/v) nei tre gruppi. Un soggetto appartenente al gruppo A (25% p/v) è stato usato per verificare la fattibilità della procedura e per stabilire una timeline radiografica approssimativa per gli studi successivi. La qualità delle immagini diagnostiche è stata valutata da tre autori in basi a criteri pre-definiti. I risultati di questo studio suggeriscono che la concentrazione ideale di mezzo contrasto per questo tipo di indagine diagnostica è del 35%. Inoltre, sono stati descritti tre pattern di distribuzione del mezzo di contrasto nel piccolo intestino, indipendenti dalla concentrazione.

Orientador: Ricardo Jannini Sawaya<br>Banca: Marcio Roberto Costa Martins<br>Banca: Laura Rodrigues Vieira de Alencar<br>Banca: Fernando Rodrigues da Silva<br>Banca: Cristiano de Campos Nogueira<br>Resumo: A Mata Atlântica da América do sul é um mosaico de diferentes fitofisionomias, relacionadas a pressões seletivas correspondentes a fatores ecológicos e evolutivos distintos, os quais regulam a distribuição da biodiversidade entre os habitats. Exploramos, neste trabalho, como a diversidade de serpentes é distribuída ao longo do gradiente latitudinal da Mata Atlântica. Primeiro analisamos a associação entre a riqueza em espécies e a diversidade filogenética de serpentes com tempo para especiação e extensão geográfica ao longo do gradiente latitudinal. Nós também exploramos as amplitudes de nicho climático destas serpentes. E, finalmente, decompusemos a composição filogenética de ilhas costeiras do sudeste da Mata Atlântica no intuito de entender como área e distância com o continente poderia afetar diferentes componentes da diversidade de serpentes. Encontramos que área é o principal fator relacionado com riqueza em espécies, independentemente do tempo para especiação. Observamos a maior riqueza em espécies em linhagens mais recentes nas zonas serranas do sudeste. Amplitudes de nicho climático, associadas à precipitação, mostraram conservação filogenética, afetando a distribuição dos clados mais recentes. Em nosso exemplo de ilhas, mostramos que distintos fatores ecológicos podem afetar riqueza em espécies e diversidade filogenética diferentemente. Desta maneira, fatores idiossincráticos poderiam gerar diferentes respostas em diferentes linhagens ao longo do gradiente...<br>Abstract: The Atlantic Forest of South America is a mosaic of different vegetation physiognomies corresponding to distinct evolutionary and ecological factors that drive biodiversity distribution. One of these factors is climatic variation. We explored herein how snake diversity, (measured as species richness and phylogenetic diversity) is distributed along the Atlantic Forest latitudinal gradient, taking area and time-for-speciation into account. We first analyzed the association of species richness and phylogenetic diversity with time-forspeciation and geographical extent along the latitudinal gradient. We also explored climatic niche breadths. And finally, we decomposed the phylogenetic composition across coastal islands in southeastern Atlantic Forest, to understand how island area and distance from the mainland drive different components of snake diversity. We found that area is a major driver of species richness, regardless of time-for-speciation. We observed higher species richness of more recent lineages in southeastern mountain ranges. Climatic niche breadths associated to precipitation showed phylogenetic conservatism, affecting the distribution of more recent clades. In our island case study, we show that distinct ecological factors can drive species richness and phylogenetic diversity differently. In this way, idiosyncratic factors generate different responses in different lineages across environmental gradients. We hope to shed some light on ecological and historical ...<br>Doutor

Thesis (Ph. D.)--Ohio State University, 2005.<br>Title from first page of PDF file. Document formatted into pages; contains xv, 107 p.; also includes graphics (some col.) Includes bibliographical references (p. 97-107). Available online via OhioLINK's ETD Center

Includes bibliographical references. The venom from the Australian brown snakes (Pseudonaja spp.) contains a strong procoagulant component that produces bleeding due to consumption of clotting factors in bite victims. Investigation of the role of phospholipid and calcium found neither was essential for activity, but calcium could shorten the clotting time.

Thesis (Ph. D.)--Georgia State University, 2006.<br>Title from file title page. Greg M. Smith, committee chair; Matthew Bernstein, Kathy Fuller-Seeley, Jack Boozer, Angelo Restivo, committee members. Electronic text (349 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed June 4, 2007. Includes bibliographical references (p. 342-348).

The study of widescreen cinema historically has been under analyzed with regard to aesthetics. This project examines the visual poetics of the wide frame from the silent films of Griffith and Gance to the CinemaScope grandeur of Preminger and Tashlin. Additionally, the roles of auteur and genre are explored as well as the new media possibilities such as letterboxing online content. If cinema’s history can be compared to painting, then prior to 1953, cinema existed as a portrait-only operation with a premium placed on vertical compositions. This is not to say that landscape shots were not possible or that lateral mise-en-scene did not exist. Cinematic texts, with very few exceptions, were composed in only one shape: the almost square Academy Ratio. Before 1953, cinema’s shape is that of portraiture; after 1953 cinema’s shape is landscape. Widescreen filmmaking is not simply an alternative to previous visual representation in cinema because no equivalent exists. Widescreen is quite simply a break from previous stylistic norms because the shape of the frame itself has been drastically reconfigured. With the proliferation of HDTV and widescreen computer monitors, certain aspect ratios that were once regarded as specifically “cinematic” are now commonplace both in the home and in the workplace. This project outlines a project that traces the innovations and aesthetic developments of widescreen aspect ratios from the silent era of D.W Griffith, Buster Keaton and Abel Gance all the way through to current widescreen digital manifestations of web-based media and digital “blanks” such as those created by Pixar. Other chapters include close textual analyses of “experimental” widescreen films of 1930, the development of “norms” for widescreen filmmaking in the early CinemaScope era of the 1950s and examinations of the experimental multi-screen mosaics of 1968 and beyond.

Chrysopelea paradisi, also known as the flying snake, possesses one of the most unique forms of aerial locomotion found in nature, using its entire body as a dynamic lifting surface without the use of wings or membranes. Unlike other airborne creatures, this species lacks appendages to aid in controlling its flight trajectory and producing lift. The snake exhibits exception gliding and maneuvering capabilities compared with other species of gliders despite this lack of appendages. While gliding, C. paradisi morphs its body by expanding its ribs, essentially doubling its width and utilizing its entire length as a reconfigurable wing. Its cross-sectional shape transforms into a thick, airfoil shape with a concave ventral surface, outwards protruding lips at the leading and trailing edges, a somewhat triangular dorsal surface with a round apex, and fore-aft symmetry. This study investigated the aerodynamic performance of this unique shape by simulating a single, static segment of the snake's body over a wide range of Reynolds numbers (3,000 to 15,000) and angles of attack (-10 to 60o) to simulate the full range of the snake's flight kinematics. This is the first study on an anatomically accurate snake model, and few aerodynamic studies have been performed in this low Reynolds number regime. Load cell measurements and time-resolved digital particle image velocimetry (TRDPIV) were performed on a 2D anatomically accurate model to determine the lift and drag coefficients, wake dynamics, and vortex shedding characteristics. This geometry produced a maximum lift coefficient of 1.9 and maximum lift to drag ratio of 2.7, and maintained increases in lift up to 35o. Overall, this geometry demonstrated robust aerodynamic behavior by maintain significant lift production and near maximum lift to drag ratios over a wide range of test parameters. These aerodynamic characteristics may enable the flying snake to glide at steep angles and over a wide range of angles of attack, often encountered in gliding trajectories. This geometry also produced larger maximum lift coefficients than many other bluff bodies and airfoils in this low Reynolds number regime. This thesis is organized as follows. The first section contains a broad introduction on gliding flight and C. paradisi's unique mode of gliding. The following section is a manuscript that will be submitted to a journal and contains the experimental analysis on the snake's cross-sectional shape. Several appendices attached to the end of this thesis contain additional analysis and work performed throughout the duration of this project and unique Matlab algorithms developed during this research.<br>Master of Science

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv & Cons Biol)<br>Gaps in our knowledge of the functional roles of snakes within ecosystems limit our ability to predict the potentially cascading effects their removal from an ecosystem might create. Extirpation of snake species could potentially result in losses of ecosystem functionality if those taxa are ecologically unique. I used pitfall and funnel trap arrays, artificial cover object surveys, active searching, and passive camera trapping, as well as pre-existing faunal diversity data to identify terrestrial tetrapod species within the Koeberg Private Nature Reserve. This resulted in a list of 265 species, of which 13 were snakes. I then gathered data on dietary and four additional functional traits for each species from the literature. Next, using hierarchical and partitioning around medoids clustering, I identified ten broad dietary guilds and 54 functional guilds within the terrestrial tetrapod community. Of the dietary guilds Dasypeltis scabra was the only snake species that formed a unique single species guild and was one of four snake species (Pseudaspis cana, Homoroselaps lacteus and Lamprophis guttatus) to form four unique single species functional guilds. The remaining snakes clustered together within groups of other vertebrate predators. Functional diversity analysis was then used to simulate losing eight major taxonomic groups (birds, passerines, non-passerines, mammals, reptiles, snakes, non-snake reptiles and amphibians) and gauge the effects of those losses on overall community dietary and functional diversity. Functional diversity analysis revealed that the loss of certain snake species resulted in disproportionate losses of overall community dietary and functional diversity while losing others had negligible effects. These findings provide ambivalent support for the dietary and functional uniqueness of snakes suggesting that certain snake species are fulfilling unique functional roles within the ecosystem. Additionally, it is likely that losing those non-redundant species would result in significant losses of ecosystem functionality.

In squamate reptiles, the evolutionary transition from oviparity to viviparity is accompanied by loss of the calcareous outer eggshell, which suggests significant implications for the role of calcium during embryonic development (Packard et al., 1977). An experiment was designed to evaluate the impact of reduced calcium availability during development in the oviparous corn snake, Pantherophis guttatus (Stewart and Ecay, 2013). Results from that study showed significant decreases in the mass and length of hatchling corn snakes when the outer calcareous eggshell layer was removed during development. In vertebrates, variation in total body length reflects skeletal differences---primarily differences in the number or sizes of vertebrae and/or differences in length of the skull. Skeletal components obviously are affected by the availability of calcium during development. My study was designed to determine the anatomical and developmental bases for the smaller size observed in hatchling snakes subjected to reduction of eggshell calcium during embryonic development. My hypotheses were, as follows: 1) Differences in mass reflected differences in overall length of hatchlings; 2) Differences in length resulted from decreased size of vertebrae---rather than decreased number---and/or decreased length of skulls in hatchlings with reduced calcium. Hatchlings were prepared for skeletal analysis via clearing-and-staining. Vertebrae of each hatchling were counted and size measurements obtained for separate spinal regions (cervical, thoracic, and caudal). Results demonstrate a significant treatment effect on size of vertebrae in the thoracic and anterior caudal regions, as well as length of the skull. These findings suggest that reduced developmental calcium, comparable to the condition in viviparous species, impacts ossification and growth of skeletal elements in late development.

Snakes are one of the world’s most versatile organisms, at ease slithering through rubble or climbing vertical tree trunks. Their adaptations for conquering complex terrain thus serve naturally as inspirations for search and rescue robotics. In a combined experimental and theoretical investigation, we elucidate the propulsion mechanisms of snakes on both hard and granular substrates. The focus of this study is on physics of snake interactions with its environment. Snakes use one of several modes of locomotion, such as slithering on flat surfaces, sidewinding on sand, or accordion-like concertina and worm-like rectilinear motion to traverse crevices. We present a series of experiments and supporting mathematical models demonstrating how snakes optimize their speed and efficiency by adjusting their frictional properties as a function of position and time. Particular attention is paid to a novel paradigm in locomotion, a snake’s active control of its scales, which enables it to modify its frictional interactions with the ground. We use this discovery to build bio-inspired limbless robots that have improved sensitivity to the current state of the art: Scalybot has individually controlled sets of belly scales enabling it to climb slopes of 55 degrees. These findings will result in developing new functional materials and control algorithms that will guide roboticists as they endeavor towards building more effective all-terrain search and rescue robots.

Made available in DSpace on 2014-10-09T12:42:35Z (GMT). No. of bitstreams: 0<br>Made available in DSpace on 2014-10-09T14:01:24Z (GMT). No. of bitstreams: 0<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>Tese (Doutoramento)<br>IPEN/T<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP<br>FAPESP:09/10305-8

Esta tesis explora los problemas de la reconstrucción 3D de los vasos coronarios a partir de angiografías: calibración, extracción de los vasos a partir de las imágenes, y reconstrucción 3D del vaso. La calibración se divide en dos procedimientos: El primer procedimiento corrige la distorsión geométrica, y el segundo se concentra en la estimación de los parámetros extrínsecos e intrínsicos del sistema de adquisición. La distorsión geométrica} introducida por el intensificador de imagen se corrige mediante la definición de un nuevo modelo de polinomios para la distorsión. La principal ventaja de esta aproximación es que la distorsión se puede corregir para cualquier vista, eliminando así la necesidad de calibrar para cada adquisición. Respecto la estimación de la geometría de adquisición}, mostramos que las asunciones hechas por otros investigadores a la hora de estimar los parámetros extrínsecos sólo son válidas en casos muy restringidos, y por tanto introducen un alto grado de error. Por ello, proponemos un modelo nuevo, más general y flexible, para calibrar los parámetros del brazo C. Gracias a este modelo, podemos obtener una estimación precisa de la geometría de adquisición. Después de calibrar, los siguientes pasos de esta tesis se refieren a la detección de los vasos y a la reconstrucción 3D. Debido a la baja relación señal-ruido de las imágenes de angiografías, la segmentación de los vasos} no es un problema trivial de resolver. Nosotros desarrollamos un filtro de difusión anisotrópica para mejorar el resultado de la segmentación de los vasos. Este filtro escoge automáticamente la escala del tensor de difusión para cada píxel y consigue un realce selectivo de los vasos. A partir de los puntos detectados del vaso, la reconstrucción 3D se consigue aplicando técnicas parecidas a las de la visión estéreo, pero evitando el problema de la determinación de las correspondencias de puntos} del objeto en las dos imágenes. Para ello, definimos los snakes biplanos, que son modelos deformables consistentes en una curva tridimensional que se deforma en el espacio para adaptar sus proyecciones a los vasos en las imágenes. Esta té cnica resuelve el problema de las correspondencias de puntos de forma inherente, y tiene un buen comportamiento cuando las condiciones de adquisición no se conocen con gran precisión. Los métodos propuestos son extensamente validados usando phantoms y secuencias reales de angiografías adquiridas con un sistema monoplano de angiografías y la inestimable ayuda de los médicos del Hospital Universitari "Germans Tries i Pujol".<br>This thesis explores all problems involved in the 3D reconstruction of coronary vessels from X-ray angiographies: calibration, vessel extraction in X-ray images and 3D reconstruction of the vessel in space. We divide the calibration into two procedures: The first procedure is devoted to the correction of the geometrical distortion, and the second one is focused on the estimation of the extrinsic and intrinsic parameters of the X-ray acquisition system. We correct the geometrical distortion} introduced by the image intensifier by defining a novel polynomial model for the distortion. The main advantage of our approach is that the distortion can be corrected for any view, and thus eliminates the need of distortion calibration for each acquisition. Regarding the estimation of the acquisition geometry}, we show that the assumptions made by other researchers to estimate the extrinsic parameters are only valid in very restricted cases and thus introduce high degree of error. Therefore, we propose a new, more general and flexible model to calibrate the parameters of the C-arm. Using our proposed model, we can obtain a highly accurate estimation of the acquisition geometry. Once calibrated, next steps of the thesis refer to vessel detection in images and 3D reconstruction. Due to the low signal-to-noise ratio of X-ray angiographies, the vessel segmentation} procedure is not a trivial procedure. We develop a new anisotropic diffusion filter that enhances the vessels on the X-ray images in order to improve the vessel segmentation result. The proposed filter automatically chooses the scale of the diffusion tensor to be applied for each pixel, and achieves selective enhancement of the vessels enhancing the contrast-to-noise ratio. Given the detected vessel points in the angiography, 3D reconstruction is applied applying techniques similar to stereo vision avoiding the problem of determining the corresponding points} of the object in both images. We define the biplane snakes that are deformable models consisting on a three-dimensional elastic curve that deforms in space to adapt its projections to the vessels in the images. The proposed approach inherently solves the point correspondence problem and has a good behaviour when the acquisition conditions are known with low precision. The proposed methods are extensively validated with imaged phantoms and real angiographic sequences acquired with a monoplane angiographic system and the valuable help of the physicians of Hospital Universitari "Germans Tries i Pujol".

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 dissertation addresses the question, how and why do 'flying' snakes (Chrysopelea) undulate through the air? Instead of deploying paired wings or wing-like surfaces, flying snakes jump, splay their ribs into a bluff-body airfoil, and undulate through the air. Aerial undulation is the dominant feature of snake flight, but its effects on locomotor performance and stability are unknown. Chapter 2 describes a new non-equilibrium framework to analyze gliding animals and how the pitch angle affects their translational motion. Chapter 3 combines flying snake glide experiments and detailed dynamic modeling to address what is aerial undulation and how each kinematic component affects rotational stability and translational performance. Chapter 4 combines the kinematic data of Chapter 3, with elements of the non-equilibrium framework of Chapter 2, to examine the kinematics of snake flight in greater detail. This chapter also tests if our current understanding of flying snake aerodynamics is sufficient to explain the observed center of mass motion.<br>Ph. D.

Flying snakes possess a sophisticated gliding ability with a unique aerial behavior, in which they flatten their body to make a roughly triangular cross-sectional shape to produce lift and gain horizontal acceleration. Also, the snakes assume an S-like posture and start to undulate by sending traveling waves down the body. The present study aims to answer how the snakes are able to control their glide trajectory and remain stable without any specialized flight surfaces. Undulation is the most prominent behavior of flying snakes and is likely to influence their dynamics and stability. To examine the effects of undulation, a number of theoretical models were used. First, only the longitudinal dynamics were considered with simple two-dimensional models, in which the snake was approximated as a number of connected airfoils. Previously measured force coefficients were used to model aerodynamic forces, and undulation was considered as periodic changes in the mass and area of the airfoils. The model was shown to be passively unstable, but it could be stabilized with a restoring pitching moment. Next, a three-dimensional model was developed, with the snake modeled as a chain of airfoils connected through revolute joints, and undulation was considered as periodic changes in the joint angles. It was shown that undulation, when added to a linearization-based closed-loop control, could increase the size of the basin of stability. Our theoretical results suggested that the snakes need some extent of closed-loop control in spite of the clear contribution of undulation to the stability of glide. Next, we considered the effects of aerodynamic interactions between the fore and the aft body on the aerodynamic performance of flying snakes. Two-dimensional anatomically accurate airfoils were used in a water tunnel. Lift and drag forces were measured by load cells, and the flow field data were obtained using digital particle image velocimetry. The results confirmed strong dependence of the aerodynamic performance on the tandem arrangement. Flow fields around the airfoils were obtained to show how the tandem arrangement modified the separated flow and the wake; therefore altering the pressure field and resulting in changes in the lift and drag.<br>Ph. D.

Active contours have been proven to be a powerful semiautomatic image segmentation approach, that seems to cope with many applications and different image modalities. However, they exhibit inherent drawbacks, including the sensibility to contour initialization due to the limited capture range of image edges and problems with concave boundary regions. The Gradient Vector Flow replaces the traditional image force and provides an enlarged capture range as well as enhanced concavity extraction capabilities, but it involves an expensive computational effort and considerably increased memory requirements at the time of computation. In this paper, we present an enhancement of the active contour model to facilitate semiautomatic contour detection in huge images. We propose a tile-based image decomposition accompanying an image force computation scheme on demand in order to minimize both computational and memory requirements. We show an efficient implementation of this approach on the basis of general purpose GPU processing providing for continuous active contour deformation without a considerable delay.

This thesis describes experiments undertaken to investigate the link between sunshinevirus virus and disease. Sunshinevirus was first discovered in a collection of Australian pythons that were euthanased because of a neurorespiratory disease outbreak. Cases of sunshinevirus infection, including chronic asymptomatic infections, have subsequently been detected throughout Australia by PCR testing, and the virus has been found in most Australian python species. There has been a documented association between sunshinevirus and disease, but no causal link had been proven. To investigate this link, and to provide information on viral transmission and pathogenesis, controlled experimental infection studies were undertaken. Carpet pythons were directly inoculated with the virus and subsequently developed infection and neurorespiratory disease. The virus was reisolated from infected pythons. An uninfected python co-housed with an infected python also became infected and developed neurological signs of disease. This is consistent with natural transmission. Clinical signs and histopathology indicated a viral predilection for the central nervous system. Clinically, pythons showed evidence of disease in the cerebellum and/or brainstem and central vestibular system, as well as the spinal cord. Histologically, there was a non-suppurative encephalomyelitis, with the most consistent finding being vacuolation and gliosis in the brain. Pathological changes were also found in a wide range of other tissues. Cytoplasmic inclusions were found in a range of predominantly epithelial tissues. Infected pythons shed virus and were viraemic for several months. Several possible routes of horizontal transmission were identified, including cloacal-oral, oral-oral and via the circulatory system. The experimental infection study proved a causal link between sunshinevirus and disease in carpet pythons. The dose of virus required to cause infection was not established and the python immune response to sunshinevirus infection remains unclear.

This thesis paper examines how I turned real life experiences and observations into a fictionalized screenplay that explores the potential for vice inherent in tip-based service industry jobs. After that, I move on to the preproduction process and touch on casting, location scouting, visualization, production design, budgeting and crewing. Next I discuss how the preproduction and on-set efforts of individuals were all critical to our production. Then I chronicle the ups and downs of postproduction. Finally, I conclude with an admittedly subjective analysis of the effectiveness of the movie itself.