Analysis of tidal strain observations in Lanzarote Island

Comunicación presntada a la 3ª Asamblea Hispano-Portuguesa de Geodesia y Geofísica = 3ª Assembleia Luso-Espanhola de Geodesia e Geofisica, celebrada en Valencia entre el 4 y el 8 de febrero de 2002.The strain response of the Earth to tidal forces is observed in the Geodynamics Laboratory of Lanzarote Island. The instruments, installed in a gallery inside the lava tunnel of Cueva de los Verdes, are kind of horizontal ceramic-tube extensometers. Their base fines comprise from 8 to 38 m length and are orientated in two orthogonal directions (45º.2 N Y 135°.2 N), which depend on the situation in the gallery. The reliability of this instruments, which measure the variation of distance between two fixed points with a resolution of 10 -10, allow us to dispose long term series of tidal strains since 1992. The data series are analysed in order to study the stability of the instruments. Also, with these data we can determine the tidal strain models, as well as the tidal deformation and the long-term variations of strains in this island. Due to the dependence of the local conditions of the station, which is located in an island, the oceanic influence will be investigated together with local atmospheric disturbing effects. These effects are carefully studied for this station, in order to allow the identification and, if possible, its separation from other signals of interest, given the volcanic feature of the island.Peer reviewe

Modulation of vascular reactivity by perivascular adipose tissue (PVAT)

Purpose of Review: In this review we discuss the role of perivascular adipose tissue (PVAT) in the modulation of vascular contractility and arterial pressure, focusing on the role of the renin-angiotensin-aldosterone system and oxidative stress/inflammation. Recent Findings: PVAT possesses an relevant endocrine-paracrine activity, which may be altered in several pathophysiological and clinical conditions. During the last two decades it has been shown PVAT may modulate vascular reactivity. It has also been previously demonstrated that inflammation in adipose tissue may be implicated in vascular dysfunction. In particular, adipocytes secrete a number of adipokines with various functions, as well as several vasoactive factors, together with components of the renin-angiotensin system which may act at local or at systemic level. It has been shown that the anticontractile effect of PVAT is lost in obesity, probably as a consequence of the development of adipocyte hypertrophy, inflammation, and oxidative stress. Summary: Adipose tissue dysfunction is interrelated with inflammation and oxidative stress, thus contributing to endothelial dysfunction observed in several pathological and clinical conditions such as obesity and hypertension. Decreased local adiponectin level, macrophage recruitment and infiltration, and activation of renin-angiotensin-aldosterone system could play an important role in this regards

Monitoring tidal and non-tidal tilt variations in Lanzarote Island (Spain)

Comunicación presentada en el XIV International Symposium on Earth Tides (ETS2000), celebrado en Mizusawa, Japón, entre el 28 de agosto y el 1 de septiembre de 2000. Las actas del congreso han sido publicadas como special issue del Journal of the Geodetic Society of Japan.Analyses of tiltmeter data frorn the Geodynarnics Observatory of Lanzarote (Canary Islands, Spain) are evaluated in order to investigate ground deforrnations. The tiltrneters are operating in two locations of the Island, with different sensitivity ranges depending on the site conditions. The results of tidal analysis show a clear influence of the ocean loading and also rneteorological disturbances. Air pressure and temperature effects are different depending on type, location and orientation of the tiltrneter, with different rnagnitude of the effect in the high and low frequency bands.Peer reviewe