A influência dos tensoativos lauril sulfato de sódio, cloreto de cetil trimetil amônio e álcool láurico etoxilado com 12 moles de óxido de etileno sobre o stratum corneum da pele de muda das cobras Bothrops jararaca e Spilotis pullatus foi avaliada através das técnicas biofísicas de PAS-FTIR, FT-Raman e DSC. Foram utilizadas soluções dos tensoativos em concentrações acima e abaixo da cmc e tratamentos por 4 e 8 horas (stratum corneum íntegro) e por 12 horas (stratum corneum após a remoção mecânica das camadas superficiais de células com fita adesiva). A presença do lauril sulfato de sódio e do cloreto de cetil trimetilamônio no stratum corneum foi detectada e a principal alteração observada para ambos foi o aumento do conteúdo hídrico do tecido; o álcool láurico etoxilado com 12 moles de óxido de etileno não promoveu aumento do conteúdo hídrico, apresentando ação de extração de lipídeos. A remoção mecânica das camadas superficiais de células com fita adesiva mostrou ser um procedimento útil para tratamento do stratum corneum da pele de muda de cobra, tornando a membrana mais adequada para estudos da ação de promotores de permeação. / The influence of the surfactants sodium lauryl sulfate, cetyl trimethyl ammonium chloride and lauryl alcohol ethoxylate (12 moles ethylene oxide) was evaluated on the stratum corneum of shed snake skin (Bothrops jararaca and Spilotis pullatus) through the biophysical techniques PAS-FTIR, FT-Raman and DSC. The surfactants were used in solutions above and below the cmc and the stratum corneum samples were pre-treated for periods of 4 and 8 hours (whole stratum corneum) and for 12 hours (stratum corneum after tape stripping procedure). The presence of the surfactants sodium lauryl sulfate and cetyl trimetyl ammonium chloride could be detected in the stratum corneum and the main change promoted by both was the increase of the water content of the membrane; the lauryl alcohol ethoxylate (12 moles ethylene oxide) did not promote increase in the hydration but showed some action as far as lipid extraction. The tape stripping procedure showed to be useful for the treatment of the stratum corneum of shed snake skin, making the membrane more adequate than the whole stratum corneum for the studies of the action of permeation enhancers.

Rodent densities were estimated in the major vegetation types of the Snake River Birds of Prey Natural Area in 1975 and 1976 by a combination of live-trapping and kill-trapping. Only deer mice (Peromyscus maniculatus) were numerous enough to permit reliable density estimates. Relative densities of other rodent species were indicated by kill-trap capture rates. Densities of deer mice correlated well (r = 0.99) with kill-trap capture rates. The use of kill -trapping in place of live-trapping in 1976 permitted extensive sampling throughout the 1930 km2 study area. Differences were found among the major vegetation and land-use types in their ability to support the rodent species representing potential prey for feeding raptors.

This thesis proposes a general and unified methodological framework suitable for studying the locomotion of a wide range of robots, especially bio-inspired. The objective of this thesis is twofold. First, it contributes to the classification of locomotion robots by adopting the mathematical tools developed by the American school of geometric mechanics.Secondly, by taking advantage of the recursive nature of the Newton-Euler formulation, it proposes numerous efficient tools in the form of computational algorithms capable of solving the external direct dynamics and the internal inverse dynamics of any locomotion robot considered as a mobile multi-body system. These generic tools can help the engineers or researchers in the design, control and motion planning of manipulators as well as locomotion robots with a large number of internal degrees of freedom. The efficient algorithms are proposed for discrete and continuous robots. These methodological tools are applied to numerous illustrative examples taken from the bio-inspired robotics such as snake-like robots, caterpillars, and others like snake-board, etc.

With exploding human populations and landscapes that are changing, an increasing number of wildlife species are brought to the brink of extinction. In Canada, the eastern hog-nosed snake, 'Heterodon platirhinos', is found in a limited portion of southern Ontario. Designated as threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), this reptile has been losing its habitat at an alarming rate. Due to the increase in development of southern Ontario, it is crucial to document what limits the snake’s habitat to direct conservation efforts better, for the long-term survival of this species. The goals of this study are: 1) to examine what environmental parameters are linked to the presence of the species at a landscape scale; 2) to predict where the snakes can be found in Ontario through GIS-based habitat suitability models (HSMs); and 3) to assess the role of biotic interactions in HSMs. Three models with high predictive power were employed: Maxent, Boosted Regression Trees (BRTs), and the Genetic Algorithm for Rule-set Production (GARP). Habitat suitability maps were constructed for the eastern hog-nosed snake for its entire Canadian distribution and models were validated with both threshold dependent and independent metrics. Maxent and BRT performed better than GARP and all models predict fewer areas of high suitability when landscape variables are used with current occurrences. Forest density and maximum temperature during the active season were the two variables that contributed the most to models predicting the current distribution of the species. Biotic variables increased the performance of models not by representing a limiting resource, but by representing the inequality of sampling and areas where forest remains. Although habitat suitability models rely on many assumptions, they remain useful in the fields of conservation and landscape management. In addition to help identify critical habitat, HSMs may be used as a tool to better manage land to allow for the survival of species at risk.

Robust object detection from registered infrared and visible image streams is proposed for outdoor surveillance. In doing this, halo effect in infrared images is used as a benefit to extract object boundary by fitting active contour models (snake) to the foreground regions where these regions are detected by using the useful information from both visual and infrared domains together. Synchronization and registration are performed for each infrared and visible image couple. Various background modeling methods such as Single Gaussian, Non- Parametric and Mixture of Gaussian models are implemented. For Single Gaussian and Mixture of Gaussian background modeling, infrared, color intensity and color channels domains are modelled separately. First of all, background subtraction is applied in the infrared domain in order to find the initial foreground regions and these are used as a mask for the foreground detection in the visible domain. After removing the shadows from the foreground regions in the visible domain, pixelwise OR operation is applied between the foreground regions of the infrared and visible couple and the final foreground mask is formed. For Non-Parametric background modeling, all domains are used altogether to extract foreground regions. For all background modelling methods, the resulting mask is used to get the final foreground regions in the infrared image. Finally, snake is applied to each connected component of the foreground regions on the infrared image for the purpose of object detection. Two datasets are used to demonstrate our results for human detection where comparisons against manually segmented human regions and against other results in the literature are presented.

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.

Thesis (M.S.)--University of Montana, 2004. / Includes bibliographical references (leaves 85-88). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.)--University of Montana, 2004. / Includes bibliographical references (leaves 85-88).

Orientador: Marcos Hikari Toyama / Resumo: Os acidentes ofídicos foram recentemente incorporados na lista de doenças tropicais negligenciadas pela Organização Mundial de Saúde (OMS). No Brasil, uma parcela significativa destes acidentes (10%) é ocasionada pela serpente Crotalus durissus terrificus (Cdt), popularmente conhecida como cascavel. Dentre os componentes do veneno, a fosfolipase A2 secretória (sPLA2) representa aproximadamente 35% da massa do veneno seco. A Cdt sPLA2 responde pela atividade mais importante e clinicamente significativa que inicia com o processo inflamatório logo após o contato com a peçonha. Quando não tratada, a peçonha pode fazer com que o indivíduo sofra com insuficiência renal aguda, a qual não é neutralizada em curto espaço de tempo, nem mesmo pelo antiveneno específico. O processo inflamatório em diversas doenças humanas, está altamente relacionado com a formação de altas quantidades de espécies reativas de oxigênio e nitrogênio (EROs e ERNs), conhecido como explosão oxidativa/nitrosativa. Este processo é combatido por moléculas de baixo peso molecular como (vitaminas D e E, e glutationa), como também por enzimas antioxidantes, como a catalase (Cat), superóxido dismutase (Sod) e peroxirredoxinas (Prx). Já foi demonstrado que as sPLA2 humanas compartilham grande similaridades bioquímicas e farmacológicas com seus homólogos de serpentes e são capazes de induzir a formação de EROs e ERNs em células de mamíferos, mas nenhum estudo até o presente momento abordou de forma sistemática danos em... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Snake envenomation have recently been added to the list of tropical neglected diseases by the World Health Organization (WHO). In Brazil, a significant portion of ophidian accidents (~ 10%) is caused by the Crotalus durissus terrificus (Cdt) snake, popularly known as rattlesnake. Among the components of the venom, secretory phospholipase A2 (sPLA2) accounts for approximately 35% of the mass of the dry venom. Cdt sPLA2 accounts for the most important clinical damages and to the ingflammmatory proccess. When untreated, venomation can cause acute renal failure, which is not neutralized in a short time, not even by the specific antivenom. The inflammatory process, which is very well characterized in several human diseases, is highly related to the formation of high amounts of reactive oxygen and nitrogen species (ROS and RNS), known as oxidative / nitrosative burst. This process is counteracted by low molecular weight molecules such as vitamins D and E and glutathione, as well as antioxidant enzymes such as peroxiredoxins (Prx). human sPLA2 share high biochemical and pharmacological similarities with their snake homologs and are able to induce the formation of ROS and RNS in mammalian cells, but no study to date has systematically addressed damage to biomolecules carried out by ROS and RNS and the expression of peroxiredoxins in response to sPLA2 administration of snakes. We have recently shown that the administration of polyphenolic extracts of Laguncularia racemosais able to in... (Complete abstract click electronic access below) / Mestre

Objetivo: descrever os achados de citologia de impressão em voluntários saudáveis e correlacioná-los com testes de olho seco e sintomatologia. Métodos: coleta de citologia de impressão (CI) da conjuntiva superior, inferior, nasal e temporal após anamnese, questionário de sintomas (QU) e exames clínicos biomicroscópicos, teste de Schirmer (TS), tempo de ruptura do filme lacrimal (TRFL), escores de fluoresceína (EF) e rosa bengala (ERB). Resultados: Foram examinados 78 olhos de 39 pacientes (30 mulheres, 85% brancos). Idade média foi de 36 anos (16-71 anos). Oitenta e cinco porcento dos pacientes eram assintomáticos no QU. TRFL médio foi de 13,6 segundos (70% ≥ 10 s), TS médio foi 19,2 mm (76% ≥ 6 mm), ERB foi 0-3 em 87%, EF foi zero em 75%. Biomicroscopia apresentou resultado normal em 65% dos olhos. CI foi normal em: 81% superior, 57% nasal, 87% inferior, 75% temporal. Foi encontrado padrão de cromatina snake-like em 15% das amostras superiores. Houve pouca correlação entre os testes clínicos, questionário e achados citológicos. A citologia de impressão do sítio nasal e a presença de cromatina snake-like associaram-se com alguns testes da superfície ocular, sintomas e com a idade dos pacientes. Conclusão: Nosso estudo encontrou 30% de testes clínicos anormais, sintomas e achados citológicos alterados (anormal e limítrofe) neste grupo de indivíduos normais. Os achados da conjuntiva bulbar da área de fenda e superior são os que mais apresentam alterações. Entretanto, apesar de algumas associações significativas, não houve correlação conclusiva entre testes, sintomas e citologia de impressão. / Purpose: To describe conjunctival findings of impression cytology in healthy volunteers and to correlate to dry eye tests and symptoms. Methods: superior, inferior, nasal and temporal bulbar conjunctivae impression cytology, symptoms questionnaire, slit lamp examination, Schirmer test (ST), tear film break-up time (TFBUT), fluorescein staining (FS) and rose Bengal staining (RBS) were evaluated. Results: 78 eyes of 39 patients (30 female, 85% white) were examined. Mean age was 36 years (16-71 years). Eighty-five percent of patients were asymptomatic in questionnaire. Mean TFBUT was 13.6 seconds (70% ≥ 10 sec), ST median was 19.2 mm (76% ≥ 6 mm), RBS grade was 0-3 in 87%, FS was 0 in 75%. Slit lamp examination did not reveal any alteration in 65% of the eyes. Impression cytology showed normal aspect in: 81% superior, 57% nasal, 87% inferior, and 75% temporal. Snake-like chromatin pattern was present in 15% of superior samples. There were few correlations among clinical tests, questionnaire result and cytological findings. Nasal impression cytology results and snake-like chromatin were associated with some ocular surface exams, symptoms and age of patients. Conclusion: Our study identified prevalence of 30% of abnormal clinical tests, symptoms, and altered cytological findings (abnormal and borderline) in this group of normal subjects. Impression cytology findings of exposed bulbar conjunctiva and superior conjunctiva are more often altered. Despite a few associations among tests, there was no conclusive correlation among these tests, symptoms and impression cytology results.