Magmatism is a critical process throughout the geological history of Earth and Mars, and one of the few processes capable of producing significant changes in the Martian surface and subsurface past the Noachian. The interaction between mafic magmatism and host rock has the potential to contribute to the surface volatile species, chief among which is sulfur. On Earth, mafic magmas intruding sulfur-rich sediments are rare; however, sulfur–rich soils exist with a near global extent on Mars, and evidence exists for both recent and ancient mafic magmatism. The intrusion of mafic magmas into sulfur-rich sediments is therefore expected on Mars, and is especially pertinent concerning proposed landing site for the ESA ExoMars mission, and the landing site of the NASA Mars 2020 mission, both of which are in proximity to a potential volcanic capping unit in direct contact with sulfate bearing sediments. Here we investigate a terrestrial analog in the San Rafael Swell on the Colorado Plateau in which numerous mafic dikes intrude, alter, and bake sulfur-rich sediments. Mafic dikes intruding the Curtis, Entrada Sandstone, and Carmel Formations act as analogs for volcanic/sediment interaction on Mars, specifically for Jezero Crater, Mawrth Vallis, and N-E Syrtis Major. Using Mars relevant instruments, mineralogical changes with respect to distance from the magmatic intrusion, as well as the spatial resolution necessary to detect these changes, are constrained. The investigated analogs are discovered to be dynamic, and similar systems on Mars will likely require both orbital and in-situ measurements to be detected due to resolution constraints.

A form of detectability, known as the input-output-to-state stability property, for singularly perturbed systems is examined in this work. This work extends the result of a paper by Christofides & Teel wherein they presented a notion of total stability for input-to-state stability with respect to singular perturbations. Analyzing singularly perturbed systems with outputs we show that if the boundary layer system is uniformly globally asymptotically stable and the reduced system is input-output-to-state stable with respect to disturbances, then these properties continue to hold, up to an arbitrarily small offset, for initial conditions in an arbitrarily large compact set and sufficiently small singular perturbation parameter over the time interval for which disturbances, their derivatives, and outputs remain in an arbitrarily large compact set. An application of the result is presented where we analyze the stability of a circuit with a nonlinear element through the measurement of only one of the variables of interest.

5 Abstract Subject of many studies dealing with interactions of predator and prey is behaviour and reactions of those predators who distinguish their prey by visual signals. The aim of the study was to compare the detectability of prey with a simple or structured body-margin shape of cryptically coloured true bugs Dysodius crenulatus and Dysodius lunatus (Aradidae) using a different type of background (tree bark of Acer, Gleditschia and Tilia). Background photos were presented in black and white and colour. The test was performed on naive birds and on the wild-caught adults of the Great Tits (Parus major) and the Blue Tits (Cyanistes caeruleus). The experiment was performed in the experimental cage with one-sided mirror glass. The influence of the body-margin shape of the prey was evident for certain groups, but the effect was depending on the age and specie of the birds and the type of the background. Different times of the search for prey were encountered as it was more difficult for birds to search for structured body-margin shape and the birds found faster preys with simple ones. When searching on the colour background the Great Tits were faster than on black and white background. Naive birds of the Great Tits were in search of prey faster than adults and vice versa with the Blue Tits. A separate task...

A form of detectability, known as the input-output-to-state stability property, for singularly perturbed systems is examined in this work. This work extends the result of a paper by Christofides & Teel wherein they presented a notion of total stability for input-to-state stability with respect to singular perturbations. Analyzing singularly perturbed systems with outputs we show that if the boundary layer system is uniformly globally asymptotically stable and the reduced system is input-output-to-state stable with respect to disturbances, then these properties continue to hold, up to an arbitrarily small offset, for initial conditions in an arbitrarily large compact set and sufficiently small singular perturbation parameter over the time interval for which disturbances, their derivatives, and outputs remain in an arbitrarily large compact set. An application of the result is presented where we analyze the stability of a circuit with a nonlinear element through the measurement of only one of the variables of interest.

Nearly extirpated from the Central Appalachians, USA by the mid-1900s as a result of human persecution, loss of forests, and absence of large mammal carrion, remnant populations of common ravens (Corvus corax) have recolonized portions of their historical range. One such area of recolonization is southeastern Kentucky where the species is listed as state threatened. Southeastern Kentucky appears to have extensive suitable breeding habitat, but raven records remain relatively rare with sightings and a few nests being confirmed during the past three decades. Because little is known about local ecology or population status of this reclusive corvid in Kentucky, I assessed distribution and occupancy of ravens in available cliff habitat to quantify factors that affect detectability of ravens, identify landscape attributes important to raven breeding locations at multiple scales, and develop a protocol for monitoring occupancy of potential raven breeding habitats in Kentucky. Based on surveys of 23 cliff sites during 2009–2010, I found that ravens are highly detectable (p=0.90 (95% CI = 0.81–0.95)) at known occupied cliff sites, suggesting a survey effort consisting of two visits, each lasting one hour, will enable occupancy to be determined with 95% confidence. Using this and the habitat information associated with occupancy (cliff area and horizontal strata orientation), a monitoring protocol was developed and initiated in 2011 that should be useful to wildlife managers and land stewards interested in long-term monitoring, management, and conservation of common ravens in Kentucky’s cliff habitat.

O atropelamento de animais silvestres é considerado como o principal fator antrópico responsável diretamente pela mortalidade de vertebrados terrestres em escala global. Estimativas de mortalidade são fundamentais para avaliar o impacto de rodovias, mas para reduzir o seu viés a remoção de carcaças e a eficiência dos observadores devem ser consideradas. Medidas mitigadoras têm sido implementadas para reduzir a mortalidade da fauna e ampliar a conectividade da paisagem, mas um fator determinante para a sua efetividade é a sua correta localização. Com o objetivo de qualificar o planejamento de medidas mitigadoras, neste trabalho procuramos responder a quatro perguntas: 1) há diferença na remoção e detectabilidade de carcaças entre diferentes grupos taxonômicos? 2) qual a influência da remoção e detectabilidade de carcaças sobre as estimativas de magnitude de mortalidade? 3) a mortalidade se distribui de forma agregada ao longo da rodovia? e 4) a distribuição espacial de atropelamentos de diferentes grupos taxonômicos é similar? Nossos resultados apontam diferenças na taxa de remoção e na detectabilidade de carcaças entre os grupos, além de demonstrar que, ao desconsiderar esses fatores, a magnitude de atropelamentos é subestimada. Ademais, nossos resultados indicam que a distribuição espacial de atropelamentos de mamíferos pode ser utilizada como indicadora da ocorrência de atropelamentos de outros grupos taxonômicos apenas em escalas menos refinadas, exigindo o planejamento de medidas mitigadoras mais amplas. Os resultados aqui apresentados devem ser considerados no monitoramento de animais atropelados e no planejamento de medidas mitigadoras do impacto de rodovias. / Vehicle-wildlife collisions are considered the main human factor responsible directly for vertebrate mortality worldwide. Roadkill estimates are elementary to evaluate road impacts, but carcass removal and searcher efficiency must be considered in order to diminish estimation bias. Mitigation measures have been implemented to reduce wildlife mortality and to increase connectivity, but their correct placement is an important factor defining the effectiveness of these measures. In order to qualify mitigation planning, in this study we aim to answer four main questions: 1) is there difference in carcass removal rates and detectability among different taxonomic groups? 2) do carcass removal and detectability influence mortality magnitude estimates? 3) are roadkills spatially aggregated? and 4) are roadkill spatial distribution of different taxonomic groups similar? Our results show differences in carcass removal and detectability among groups, and demonstrate that mortality magnitude is underestimated when these factors are not considered. Also, our results indicate that mammal roadkill aggregations may be used as a surrogate of roadkill aggregations of other taxonomic groups in larger scales. The results presented here must be considered in roadkill monitoring and in mitigation measures planning.

O atropelamento de animais silvestres é considerado como o principal fator antrópico responsável diretamente pela mortalidade de vertebrados terrestres em escala global. Estimativas de mortalidade são fundamentais para avaliar o impacto de rodovias, mas para reduzir o seu viés a remoção de carcaças e a eficiência dos observadores devem ser consideradas. Medidas mitigadoras têm sido implementadas para reduzir a mortalidade da fauna e ampliar a conectividade da paisagem, mas um fator determinante para a sua efetividade é a sua correta localização. Com o objetivo de qualificar o planejamento de medidas mitigadoras, neste trabalho procuramos responder a quatro perguntas: 1) há diferença na remoção e detectabilidade de carcaças entre diferentes grupos taxonômicos? 2) qual a influência da remoção e detectabilidade de carcaças sobre as estimativas de magnitude de mortalidade? 3) a mortalidade se distribui de forma agregada ao longo da rodovia? e 4) a distribuição espacial de atropelamentos de diferentes grupos taxonômicos é similar? Nossos resultados apontam diferenças na taxa de remoção e na detectabilidade de carcaças entre os grupos, além de demonstrar que, ao desconsiderar esses fatores, a magnitude de atropelamentos é subestimada. Ademais, nossos resultados indicam que a distribuição espacial de atropelamentos de mamíferos pode ser utilizada como indicadora da ocorrência de atropelamentos de outros grupos taxonômicos apenas em escalas menos refinadas, exigindo o planejamento de medidas mitigadoras mais amplas. Os resultados aqui apresentados devem ser considerados no monitoramento de animais atropelados e no planejamento de medidas mitigadoras do impacto de rodovias. / Vehicle-wildlife collisions are considered the main human factor responsible directly for vertebrate mortality worldwide. Roadkill estimates are elementary to evaluate road impacts, but carcass removal and searcher efficiency must be considered in order to diminish estimation bias. Mitigation measures have been implemented to reduce wildlife mortality and to increase connectivity, but their correct placement is an important factor defining the effectiveness of these measures. In order to qualify mitigation planning, in this study we aim to answer four main questions: 1) is there difference in carcass removal rates and detectability among different taxonomic groups? 2) do carcass removal and detectability influence mortality magnitude estimates? 3) are roadkills spatially aggregated? and 4) are roadkill spatial distribution of different taxonomic groups similar? Our results show differences in carcass removal and detectability among groups, and demonstrate that mortality magnitude is underestimated when these factors are not considered. Also, our results indicate that mammal roadkill aggregations may be used as a surrogate of roadkill aggregations of other taxonomic groups in larger scales. The results presented here must be considered in roadkill monitoring and in mitigation measures planning.

O atropelamento de animais silvestres é considerado como o principal fator antrópico responsável diretamente pela mortalidade de vertebrados terrestres em escala global. Estimativas de mortalidade são fundamentais para avaliar o impacto de rodovias, mas para reduzir o seu viés a remoção de carcaças e a eficiência dos observadores devem ser consideradas. Medidas mitigadoras têm sido implementadas para reduzir a mortalidade da fauna e ampliar a conectividade da paisagem, mas um fator determinante para a sua efetividade é a sua correta localização. Com o objetivo de qualificar o planejamento de medidas mitigadoras, neste trabalho procuramos responder a quatro perguntas: 1) há diferença na remoção e detectabilidade de carcaças entre diferentes grupos taxonômicos? 2) qual a influência da remoção e detectabilidade de carcaças sobre as estimativas de magnitude de mortalidade? 3) a mortalidade se distribui de forma agregada ao longo da rodovia? e 4) a distribuição espacial de atropelamentos de diferentes grupos taxonômicos é similar? Nossos resultados apontam diferenças na taxa de remoção e na detectabilidade de carcaças entre os grupos, além de demonstrar que, ao desconsiderar esses fatores, a magnitude de atropelamentos é subestimada. Ademais, nossos resultados indicam que a distribuição espacial de atropelamentos de mamíferos pode ser utilizada como indicadora da ocorrência de atropelamentos de outros grupos taxonômicos apenas em escalas menos refinadas, exigindo o planejamento de medidas mitigadoras mais amplas. Os resultados aqui apresentados devem ser considerados no monitoramento de animais atropelados e no planejamento de medidas mitigadoras do impacto de rodovias. / Vehicle-wildlife collisions are considered the main human factor responsible directly for vertebrate mortality worldwide. Roadkill estimates are elementary to evaluate road impacts, but carcass removal and searcher efficiency must be considered in order to diminish estimation bias. Mitigation measures have been implemented to reduce wildlife mortality and to increase connectivity, but their correct placement is an important factor defining the effectiveness of these measures. In order to qualify mitigation planning, in this study we aim to answer four main questions: 1) is there difference in carcass removal rates and detectability among different taxonomic groups? 2) do carcass removal and detectability influence mortality magnitude estimates? 3) are roadkills spatially aggregated? and 4) are roadkill spatial distribution of different taxonomic groups similar? Our results show differences in carcass removal and detectability among groups, and demonstrate that mortality magnitude is underestimated when these factors are not considered. Also, our results indicate that mammal roadkill aggregations may be used as a surrogate of roadkill aggregations of other taxonomic groups in larger scales. The results presented here must be considered in roadkill monitoring and in mitigation measures planning.

No description available.

La stéganographie est l'art de la communication secrète. L'objectif est de dissimuler un message secret dans un médium anodin de sorte qu'il soit indétectable. De nos jours, avec la généralisation d'Internet et l'apparition des supports numériques (fichiers audio, vidéos ou images), plusieurs philosophies de conception de schéma stéganographique ont été proposées. Parmi les méthodes actuelles appliquées aux images numériques naturelles, nous trouvons les méthodes d'insertion adaptative, dont le principe repose sur la modification du médium de couverture avec une garantie d'avoir un certain niveau de sécurité. Ces méthodes représentent une véritable avancée en stéganographie.Dans ce manuscrit, après avoir rappelé les concepts récents de stéganographie adaptative, nous présentons une procédure automatique et complète pour l'insertion adaptative de données secrètes dans des images numériques naturelles. L'approche proposée est une « méta-méthode » basée « oracle », appelée ASO (Adaptive Steganography by Oracle), qui permet de préserver à la fois la distribution de l'image de couverture et la distribution de la base d'images utilisée par l'émetteur. Notre approche permet d'obtenir des résultats nettement supérieurs aux méthodes actuelles de l'état de l'art, et est donc l'une, si ce n'est la meilleure approche du moment. Par ailleurs, nous définissons également un nouveau paradigme en stéganographie qui est la stéganographie par base, ainsi qu'une nouvelle mesure de sélection pour les images stéganographiées, permettant d'améliorer encore plus les performances de notre schéma d'insertion. Les différentes expérimentations, que nous avons effectuées sur des images réelles, ont confirmé la pertinence de cette nouvelle approche. / Steganography is the art of secret communication. The goal is to hide a secret message in an unsuspicious object in such a way that no one can detect it. Nowadays, with the Internet spread and the emergence of digital supports (audio files, videos, or images), several philosophies of designing steganographic methods were proposed. One of the most usual embedding methods used with real digital images is the adaptive embedding algorithms, which is based on the modification of the cover image with a guarantee of a certain security level. These methods represent an important progress in steganography.In this Ph.D. Thesis, we present a fully automated procedure for the adaptive embedding of secret data in digital images. For this, after recalling the recent concepts of adaptive steganography, we first introduce a clear formalism to define a new "meta-method" steganographic approach based on "oracle", whichwe called ASO (Adaptive Steganography by Oracle). Then, we define a new steganographic paradigm called "the steganography by database paradigm", and propose a new selection criterion to further enhance the security of the transmission phase of ASO. Experimental results show that our embedding approach ASO provides the highest level of steganographic security. It is then currently the best or one of the best approaches of the state of the art.