The chemically zoned 1949 eruption on La Palma (Canary Islands): Petrologic evolution and magma supply dynamics of a rift zone eruption

The 1949 rift zone eruption along the Cumbre Vieja ridge on La Palma involved three eruptive centers, 3 km spaced apart, and was chemically and mineralogically zoned. Duraznero crater erupted tephrite for 14 days and shut down upon the opening of Llano del Banco, a fissure that issued first tephrite and, after 3 days, basanite. Hoyo Negro crater opened 4 days later and erupted basanite, tephrite, and phonotephrite, while Llano del Banco continued to issue basanite. The eruption ended with Duraznero erupting basanite with abundant crustal and mantle xenoliths. The tephrites and basanites from Duraznero and Llano del Banco show narrow compositional ranges and define a bimodal suite. Each batch ascended and evolved separately without significant intermixing, as did the Hoyo Negro basanite, which formed at lower degrees of melting. The magmas fractionated clinopyroxene +olivine±kaersutite±Ti-magnetite at 600–800 MPa and possibly 800–1100 MPa. Abundant reversely zoned phenocrysts reflect mixing with evolved melts at mantle depths. Probably as early as 1936, Hoyo Negro basanite entered the deep rift system at 200–350 MPa. Some shallower pockets of this basanite evolved to phonotephrite through differentiation and assimilation of wall rock. A few months prior to eruption, a mixing event in the mantle may have triggered the final ascent of the magmas. Most of the erupted tephrite and basanite ascended from mantle depths within hours to days without prolonged storage in crustal reservoirs. The Cumbre Vieja rift zone differs from the rift zones of Kilauea volcano (Hawaii) in lacking a summit caldera or a summit reservoir feeding the rift system and in being smaller and less active with most of the rift magma solidifying between eruptions

Historia de la acción cultural en la Guinea Española : (con notas sobre la enseñanza en el Africa Negra)

Precede al tit.: Dirección General de Marruecos y Colonia

Validated HPLC method for cynarin determination in biological samples

En el presente trabajo se describe y valida parcialmente un método simple y con una adecuada sensiblilidad para la determinación de cinarina en plasma. Este método fue utilizado para determinar el perfil farmacocinético de la cinarina luego de la administración endovenosa a ratas wistar. La cinarina fue aislada del plasma de rata por extracción en fase sólida. Las muestras obtenidas se analizaron por HPLC en fase reversa con detección ultravioleta.A simple and sensitive method for the determination of cynarin is described and partially validated. The assay was used to determine the pharmacokinetic profile of cynarin after Wistar rat intravenous administration. Cynarin was isolated from rat plasma by solid-phase extraction. Separations were performed by reversed-phase high-performance liquid chromatography with ultraviolet detection.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Validated HPLC method for cynarin determination in biological samples

En el presente trabajo se describe y valida parcialmente un método simple y con una adecuada sensiblilidad para la determinación de cinarina en plasma. Este método fue utilizado para determinar el perfil farmacocinético de la cinarina luego de la administración endovenosa a ratas wistar. La cinarina fue aislada del plasma de rata por extracción en fase sólida. Las muestras obtenidas se analizaron por HPLC en fase reversa con detección ultravioleta.A simple and sensitive method for the determination of cynarin is described and partially validated. The assay was used to determine the pharmacokinetic profile of cynarin after Wistar rat intravenous administration. Cynarin was isolated from rat plasma by solid-phase extraction. Separations were performed by reversed-phase high-performance liquid chromatography with ultraviolet detection.Colegio de Farmacéuticos de la Provincia de Buenos Aire

África: Cuerpos colonizados, cuerpos como identidades

Given the great importance that all society attach to the body, regarding its conceptualization as well as the criteria for its social presentation, it is not surprising at all that the body occupies a central place in the processes of colonization and colonial policies. This article, based on the new approaches of postcolonial studies, as well as on anthropological and sociological theory on the body in general, discusses the relationship we can establish between coloniality and the social presentation of the body. Drawing on concrete cases of European colonization in Africa, the article focuses on practices related to the use of clothing as well as body modification. If the establishment of identities is crucial for building a hierarchical social order, these specific aspects of the social presentation of the body have had an important role in subalternization processes, the very notion of <i>savage</i> being one of the clearest examples.<br><br>Dada la gran importancia que toda sociedad otorga al cuerpo, tanto a su conceptualización como a los criterios para su presentación social, no es de extrañar que el cuerpo ocupe un lugar central en los procesos de colonización y las políticas coloniales. En este artículo se analiza la relación que podemos establecer entre colonialidad y presentación social del cuerpo, sirviéndonos para ello de los nuevos enfoques de los estudios postcoloniales, así como de la teoría antropológica y sociológica sobre el cuerpo en general. A partir de casos concretos de la colonización europea en África, el artículo se centra especialmente en las prácticas relativas al uso de indumentaria, así como a las modificaciones corporales. Si el establecimiento de identidades es crucial para construir un orden social jerarquizado, estos aspectos concretos de la presentación social del cuerpo han tenido un papel relevante en los procesos de subalternización, siendo la misma noción de <i>salvaje</i> uno de los ejemplos más claros para ello

Submarine landslides around the Canary Islands

The morphology and structure of the submarine flanks of the Canary Islands were mapped using the GLORIA long-range side-scan sonar system, bathymetric multibeam systems, and sediment echosounders. Twelve young (<2 Ma) giant landslides have been identified on the submarine flanks of the Canary Islands up to now. Older landslide events are long buried under a thick sediment cover due to high sedimentation rates around the Canary Islands. Most slides were found on the flanks of the youngest and most active islands of La Palma, El Hierro, and Tenerife, but young giant landslides were also identified on the flanks of the older (15–20 Ma) but still active eastern islands. Large-scale mass wasting is an important process during all periods of major magmatic activity. The long-lived volcanic constructive history of the islands of the Canary Archipelago is balanced by a correspondingly long history of destruction, resulting in a higher landslide frequency for the Canary Islands compared to the Hawaiian Islands, where giant landslides only occur late in the period of active shield growth. The lower stability of the flanks of the Canaries is probably due to the much steeper slopes of the islands, a result of the abundance of highly evolved intrusive and extrusive rocks. Another reason for the enhanced slope instability is the abundance of pyroclastic deposits on Canary Islands resulting from frequent explosive eruptions due to the elevated volatile contents in the highly alkalic magmas. Dike-induced rifting is most likely the main trigger mechanism for destabilization of the flanks. Flank collapses are a major geological hazard for the Canary Islands due to the sector collapses themselves as well as triggering of tsunamis. In at least one case, a giant lateral blast occurred when an active magmatic or hydrothermal system became unroofed during flank collapse