Geomorphologic mapping of titan's polar terrains: Constraining surface processes and landscape evolution

We present a geomorphologic map of Titan's polar terrains. The map was generated from a combination of Cassini Synthetic Aperture Radar (SAR) and Imaging Science Subsystem imaging products, as well as altimetry, SARTopo and radargrammetry topographic datasets. In combining imagery with topographic data, our geomorphologic map reveals a stratigraphic sequence from which we infer process interactions between units. In mapping both polar regions with the same geomorphologic units, we conclude that processes that formed the terrains of the north polar region also acted to form the landscape we observe at the south. Uniform, SAR-dark plains are interpreted as sedimentary deposits, and are bounded by moderately dissected uplands. These plains contain the highest density of filled and empty lake depressions, and canyons. These units unconformably overlay a basement rock that outcrops as mountains and SAR-bright dissected terrains at various elevations across both poles. All these units are then superposed by surficial units that slope towards the seas, suggestive of subsequent overland transport of sediment. From estimates of the depths of the embedded empty depressions and canyons that drain into the seas, the SAR-dark plains must be >600 m thick in places, though the thickness may vary across the poles. At the lowest elevations of each polar region, there are large seas, which are currently liquid methane/ethane filled at the north and empty at the south. The large plains deposits and the surrounding hillslopes may represent remnant landforms that are a result of previously vast polar oceans, where larger liquid bodies may have allowed for a sustained accumulation of soluble and insoluble sediments, potentially forming layered sedimentary deposits. Coupled with vertical crustal movements, the resulting layers would be of varying solubilities and erosional resistances, allowing formation of the complex landscape that we observe today

NSAID enteropathy: could probiotics prevent it?

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used drugs in the world; nevertheless, about 50-70\ua0% of patients on long-term NSAIDs develop small intestine injury, namely NSAID enteropathy, sometimes with serious outcomes. No medications with proven efficacy are yet available to prevent NSAID enteropathy. A series of therapeutic strategies targeting the different mechanisms involved in small bowel injury have been investigated, but without definitive results. Intestinal bacteria and their degradation products are essential for the development of NSAID-induced small bowel lesions, because "germ-free" animals were found to be resistant to indomethacin injuries. Therefore, it has been suggested that modulating the intestinal flora, for example by using probiotics, could protect against NSAID enteropathy. In this work, we reviewed the main therapeutic strategies for NSAID enteropathy, in particular analyzing the available studies relating to the eventual protective role of probiotics. We found that results are not all concordant; nevertheless, the more recent studies provide better understanding about pathogenetic mechanisms involved in small intestinal injury and the role of probiotics, and show encouraging results. Larger and well-designed studies should be performed to evaluate the actual role of probiotics in NSAID enteropathy, the eventual differences among probiotic strains, dose-responses, and optimal duration of therapy