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Copyright of Revue Francaise d'Allergologie is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: The explosive activity of Popocatépetl Volcano is a threat to the surrounding densely populated areas and it is therefore important to recognize indicators of change in eruptive style (explosive to dome building) within a short period of time. In this study we present results of vesicle size distributions (VSDs) and compositional analysis of matrix glass from juvenile clasts from five of the main plinian eruptions of Popocatépetl (ca. 23–1.2ka), the 2001 small eruption during partial dome collapse and four eruptions during 1997 (May 11th and June 14th, 15th and 30th). Major element analysis of matrix glass (WDS-EPMA) allows the estimation of the depth from which the erupted magma went into disequilibrium (between crystals and melt), by calculating the equilibrium pressure using the quartz–albite–orthoclase ternary system of Blundy and Cashman (2001). Quantitative interpretation of texture in juvenile (pumice or scoria) clasts via VSD analysis using CSD software was used to link physical changes experienced by magma during ascent, with conditions responsible for eruptions. The extent and style of vesiculation in juvenile clasts is also related to eruption style and duration and has specifically allowed the recognition of changes in vesicular texture that represent variations from explosive to dome building activity (Mangan and Sisson, 2000; Adams et al., 2006). This study highlights a more complicated story in terms of magma storage, than that previously accepted for the Popocatépetl volcanic system and is an important contribution to ongoing research at the volcano. [Copyright &y& Elsevier]

The provenance and nature of palygorskite clay used by Mayas for the creation of the outstanding Maya Blue pigment and pottery in the Yucatán peninsula has not been analyzed thoroughly. Especially the hypothesis of palygorskite being a diagenetic product of volcanic glass has remained uncertain. Here, we present a detailed study of zircon extracted from palygorskite-rich materials (sak lu'um) collected in the interior of the Sacalum cenote and near Chapab village, to evaluate the potential of zircon as an indicator mineral for tephra-derived palygorskite or clay-rich deposits intercalated with carbonate rocks. U-Pb zircon geochronology and correlative trace element analyses from stratigraphically different palygorskite-rich horizons indicate a restricted Eocene age range, which is coeval to the deposition of the host carbonates, and discrete airborne emplacement events of silicic tephra into warm and shallow waters at ca. 50 Ma and 41 Ma, likely derived from volcanoes in a continental magmatic arc. Our findings also indicate that palygorskite deposits in the Yucatán peninsula are not inherited from continental sources but rather formed in-situ partly from weathering of volcanic glass that sourced Si and Al required for palygorskite formation. • Silicic tephra is a precursor component for palygorskite in Yucatán, Mexico. • Eocene zircon in palygorskite deposits are coeval to carbonate formation. • Trace elements in zircon suggest ash derivation from a continental arc setting. • Tephra origin as fall-out from western Central American or Caribbean arcs. [ABSTRACT FROM AUTHOR]

Anthropogenic climate change is altering the management of production forests. These changes are motivated by the need to adapt to the uncertainties and risks of climate change, and by the need to enlist their carbon storage and sequestration capacity as part of global mitigation efforts. These changes do however raise concerns regarding the potential implications for forest biodiversity. Here we evaluate these concerns by assessing the biodiversity implications of climate change adaptation and mitigation strategies (CCAMS) being implemented in the production forests of Sweden. We do so by identifying biodiversity goals aimed specifically at closing the existing gap between the habitat requirements of forest-dependent species, and the conditions provided by production forests, in terms of tree species composition, forest structures, and spatio-temporal forest patterns. We then use the existing literature to determine whether and by which pathway each CCAMS is likely to bridge or extend this gap. Our results indicate that CCAMS will often come into direct or partial conflict with Swedish biodiversity goals in production forests. Furthermore, some CCAMS which are inconsistent with biodiversity goals, such as logging residue removal, are being implemented more extensively than those which were most consistent with biodiversity goals. We nevertheless challenge the necessity of setting the preservation of forest biodiversity against climate change mitigation and adaptation. We clarify how CCAMS with negative biodiversity implications may still be implemented without adverse outcomes, if coupled with conservation interventions, or combined with other CCAMS deemed complementary in habitat provision. [ABSTRACT FROM AUTHOR]