Sea level anomaly on the Patagonian continental shelf: Trends, annual patterns and geostrophic flows.

We study the annual patterns and linear trend of satellite sea level anomaly (SLA) over the southwest South Atlantic continental shelf (SWACS) between 54ºS and 36ºS. Results show that south of 42°S the thermal steric effect explains nearly 100% of the annual amplitude of the SLA, while north of 42°S it explains less than 60%. This difference is due to the halosteric contribution. The annual wind variability plays a minor role over the whole continental shelf. The temporal linear trend in SLA ranges between 1 and 5 mm/yr (95% confidence level). The largest linear trends are found north of 39°S, at 42°S and at 50°S. We propose that in the northern region the large positive linear trends are associated with local changes in the density field caused by advective effects in response to a southward displacement of the South Atlantic High. The causes of the relative large SLA trends in two southern coastal regions are discussed as a function meridional wind stress and river discharge. Finally, we combined the annual cycle of SLA with the mean dynamic topography to estimate the absolute geostrophic velocities. This approach provides the first comprehensive description of the seasonal component of SWACS circulation based on satellite observations. The general circulation of the SWACS is northeastward with stronger/weaker geostrophic currents in austral summer/winter. At all latitudes, geostrophic velocities are larger (up to 20 cm/s) close to the shelf-break and decrease toward the coast. This spatio-temporal pattern is more intense north of 45°S.

Marine floating microbial fuel cell involving aerobic biofilm on stainless steel cathodes.

Here is presented a new design of a floating marine MFC in which the inter-electrode space is constant. This design allows the generation of stable current for applications in environments where the water column is large or subject to fluctuations such as tidal effects. The operation of the first prototype was validated by running a continuous test campaign for 6months. Performance in terms of electricity generation was already equivalent to what is conventionally reported in the literature with basic benthic MFCs despite the identification of a large internal resistance in the proposed design of the floating system. This high internal resistance is mainly explained by poor positioning of the membrane separating the anode compartment from the open seawater. The future objectives are to achieve more consistent performance and a second-generation prototype is now being developed, mainly incorporating a modification of the separator position and a stainless steel biocathode with a large bioavailable surface.

Aneurisma de aorta abdominal asociado a riñones en herradura / Abdominal aortic aneurysm associated to horseshoe kidney

La asociación entre riñón en herradura y aneurisma es una entidad poco común, que tiene una incidencia de 0,5 a 0,8 por ciento. Se presenta un caso clínico de esta patología, el cual fue diagnósticado en el período preoperatorio y que fue intervenido, demostrándose la presencia de aneurisma de aorta por encima del cuello del aneurisma y la presenci de un itsmo renal constituido por fino parénquima, por lo cual se pido seccionar y tratar el aneurisma en foam clásica. Se discute el riesgo quirúrgico que representa operar esta patología como son las anomalías de la vascularización renal, la presencia del itsmo renal que dificulta la resección del aneurisma y la localización de los ureteres que puede significar una injuria durante la intervención. De allí la necesidad de efectuar un exhaustivo estudio preoperatorio de esta patología