Notícias da Actividade Cultural. III Seminário de Ara do Noroeste Peníninsular. El Castro de Vigo y el comercio atlântico romano en el Noroeste Peninsular.

94 Jan.-Dez. 1984, p. 371-387

Campañas arqueológicas en el Castro de Vigo 1981-1985, Espanha.

95 Jan.-Dez. 1985, p. 97-117

Rumo ao monitoramento contínuo de variáveis oceanográficas no Parque Nacional Isla de Flores, Uruguai

Las mediciones continuas de variables ambientales en zonas costeras son fundamentales para comprender la compleja dinámica de los procesos oceanográficos y atmosféricos, así como mejorar la comprensión del medio marino para fines operativos y de conservación que se puedan integrar en un proceso de planificación espacial marina. En Uruguay se han llevado adelante distintos esfuerzos para la generación de este tipo de información in situ, pero en su mayoría no lograron mantenerse en el tiempo, principalmente por los altos costos operativos y de mantenimiento de sensores específicos. En este trabajo se presentan los resultados preliminares de más de un año de mediciones continuas de temperatura y salinidad en el Río de la Plata, obtenidos a partir de soluciones de bajo costo y un fuerte trabajo de coordinación multiinstitucional entre la academia y organismos del Estado. Las mediciones fueron obtenidas a partir de la instalación de sensores DST-CTD en el Parque Nacional Isla de Flores, un sitio clave para el muestreo de la zona exterior del Río de la Plata. Se destaca el valor de contar con este tipo de información, y se discute la importancia y complejidad de la implementación de un sistema de monitoreo continuo a largo plazo.Continuous measurements of environmental conditions in coastal zones are key to understanding oceanographic and atmospheric processes, as well as improving the understanding of the marine environment for operational and conservation purposes that can be integrated into a marine spatial planning process. Several efforts have been made in Uruguay in order to achieve these goals, but they have not sustained over time due to high operative and maintenance costs of specific sensors. This work presents the first results of more than a year of continuous measurements of temperature and salinity in the Río de la Plata obtained using a low cost solution and through a high-commitment multi-institutional teamwork between the academy and state agencies. Measurements were obtained with a DST-CTD sensor installed in Isla de Flores National Park, a key sampling point for the external zone of Río de la Plata. The relevance of having this type of information is presented and the need for the implementation of a continuous long-term monitoring system is discussed

Outer shelf seafloor geomorphology along a carbonate escarpment: The eastern Malta Plateau, Mediterranean Sea

Submarine carbonate escarpments, documented in numerous sites around the world, consist of thick exposures of Mesozoic shallow water carbonate sequences – primarily limestones and dolomites – with reliefs of >1 km and slope gradients of >70°. Whilst most research efforts have focused on the processes that shaped carbonate escarpments into complex and extreme terrains, little attention has been paid to the geomorphology of shelves upslope of carbonate escarpments. In this study we investigate high resolution geophysical, sedimentological and visual data acquired from the eastern Malta Plateau, central Mediterranean Sea, to demonstrate that the outer shelf of a carbonate escarpment is directly influenced by escarpment-forming processes. We document forty eight erosional scars, six long channels and numerous smaller-scale channels, three elongate mounds, and an elongate ridge across the eastern Malta Plateau. By analysing their morphology, seismic character, and sedimentological properties, we infer that the seafloor of the eastern Malta Plateau has been modified by three key processes: (i) Mass movements – in the form of translational slides, spreading and debris flows – that mobilised stratified Plio-Pleistocene hemipelagic mud along the shelf break and that were likely triggered by seismicity and loss of support due to canyon erosion across the upper Malta Escarpment; (ii) NNW-SSE trending sinistral strike-slip deformation in Cenozoic carbonates – resulting from the development of a mega-hinge fault system along the Malta Escarpment since the Late Mesozoic, and SE-NW directed horizontal shortening since the Late Miocene – which gave rise to NW-SE oriented extensional grabens and a NNW-SSE horst; (iii) Flow of bottom currents perpendicular and parallel to the Malta Escarpment, associated with either Modified Atlantic Water flows during sea level lowstands and/or Levantine Intermediate Water flows at present, which was responsible for sediment erosion and deposition in the form of channels and contouritic drifts

Relative effects of furosemide and ethacrynic acid on ion transport and energy metabolism in slices of rat kidney-cortex

The effects of furosemide and ethacrynic acid have been studied using slices of rat kidney cortex incubated in a Ringer medium. At concentrations from 0.2–2.0 mM, furosemide had no significant effect on the tissue ATP content or on the metabolism-dependent net movements of intracellular Na + , K + and Ca 2+ . It did, however, induce an increase in the net, outward movement of Cl − ; we suggest that this may have srisen from inhibition of a Cl − accumulating mechanism. In contrast, ethacrynic acid in the same concentration range caused marked reduction of cell respiration and ATP content and virtually total inhibitition of several processes of ion transport (Na + , Cl − and Ca 2+ loss, and K + uptake). Concentrations of furosemide greater than 5 mM caused marked inhibition of energy metabolism and transport of ions, and 10 mM furosemide had quantitatively similar effects to 2 mM ethacrynic acid. Electron micrographs of kidney-cortex slices treated with the diuretics at 2 mM show that the ultrastructure was well maintained in the presence of furosemide but that ethacrynic acid caused severe structural disorganisation and necrosis. The mitochondria were generally in the orthodox configuration in the presence of furosemide, but swollen in ethacrynic acid in accord with the marked effects of 2 mM ethacrynate on mitochondrial energy metabolism. Of the effects we have detected, that of low concentrations of furosemide on Cl − movement appears to be rather specific. Higher concentrations of this agent (5 mM and above), and all concentrations of ethacrynic acid studied (0.1–5.0 mM), have several inhibitory effects which seem to result from primary inhibition of mitochondrial activities and are presumably manifestations of toxicity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46309/1/210_2004_Article_BF00506264.pd

Análisis macroecológico y ecosistémico de la biodiversidad costera en Uruguay :implicancias para la conservación y el manejo de los recursos pesqueros

Tribunal: Daniel Conde, Diego Lercari y Alejandro Brazeiro.Orientador: Omar Defe

Hypothalamic Mitochondrial Dysfunction as a Target in Obesity and Metabolic Disease

Mitochondria are important organelles for the adaptation to energy demand that play a central role in bioenergetics metabolism. The mitochondrial architecture and mitochondrial machinery exhibits a high degree of adaptation in relation to nutrient availability. On the other hand, its disruption markedly affects energy homeostasis. The brain, more specifically the hypothalamus, is the main hub that controls energy homeostasis. Nevertheless, until now, almost all studies in relation to mitochondrial dysfunction and energy metabolism have focused in peripheral tissues like brown adipose tissue, muscle, and pancreas. In this review, we highlight the relevance of the hypothalamus and the influence on mitochondrial machinery in its function as well as its consequences in terms of alterations in both energy and metabolic homeostasis