Total mercury and total methylmercury during the POLARSTERN cruise ARK-XXVI/3 (TransArc)

Methylmercury (MeHg) is a neurotoxic compound that threatens wildlife and human health across the Arctic region. Though much is known about the source and dynamics of its inorganic mercury (Hg) precursor, the exact origin of the high MeHg concentrations in Arctic biota remains uncertain. Arctic coastal sediments, coastal marine waters and surface snow are known sites for MeHg production. Observations on marine Hg dynamics, however, have been restricted to the Canadian Archipelago and the Beaufort Sea (<79°N). Here we present the first central Arctic Ocean (79-90°N) profiles for total mercury (tHg) and MeHg. We find elevated tHg and MeHg concentrations in the marginal sea ice zone (81-85°N). Similar to other open ocean basins, Arctic MeHg concentration maxima also occur in the pycnocline waters, but at much shallower depths (150-200 m). The shallow MeHg maxima just below the productive surface layer possibly result in enhanced biological uptake at the base of the Arctic marine food web and may explain the elevated MeHg concentrations in Arctic biota. We suggest that Arctic warming, through thinning sea ice, extension of the seasonal sea ice zone, intensified surface ocean stratification and shifts in plankton ecodynamics, will likely lead to higher marine MeHg production.

Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B3: Area 5)

Peer reviewed

Radon 222 and Radium 226 measured on water bottle samples during POLARSTERN cruise ARK-XXVI/3 (TransArc)

Air-sea gas exchange plays a key role in the cycling of greenhouse and other biogeochemically important gases. Although air-sea gas transfer is expected to change as a consequence of the rapid decline in summer Arctic sea ice cover, little is known about the effect of sea ice cover on gas exchange fluxes, especially in the marginal ice zone. During the Polarstern expedition ARK-XXVI/3 (TransArc, August/September 2011) to the central Arctic Ocean, we compared 222Rn/226Ra ratios in the upper 50 m of 14 ice-covered and 4 ice-free stations. At three of the ice-free stations, we find 222Rn-based gas transfer coefficients in good agreement with expectation based on published relationships between gas transfer and wind speed over open water when accounting for wind history from wind reanalysis data. We hypothesize that the low gas transfer rate at the fourth station results from reduced fetch due to the proximity of the ice edge, or lateral exchange across the front at the ice edge by restratification. No significant radon deficit could be observed at the ice-covered stations. At these stations, the average gas transfer velocity was less than 0.1 m/d (97.5% confidence), compared to 0.5-2.2 m/d expected for open water. Our results show that air-sea gas exchange in an ice-covered ocean is reduced by at least an order of magnitude compared to open water. In contrast to previous studies, we show that in partially ice-covered regions, gas exchange is lower than expected based on a linear scaling to percent ice cover.

Under-ice fauna, sea-ice concentration, sea-ice thickness and under-ice water parameters from the Eurasian central Arctic Ocean during POLARSTERN cruise ARK-XXVII/3 (PS80) in August-September 2012

Arctic sea-ice decline is expected to have a significant impact on Arctic marine ecosystems. Ice-associated fauna play a key role in this context because they constitute a unique part of Arctic biodiversity and transmit carbon from sea-ice algae into pelagic and benthic food webs. Our study presents the first regional-scale record of under-ice faunal distribution and the environmental characteristics of under-ice habitats throughout the Eurasian Basin. Sampling was conducted with a Surface and Under-Ice Trawl, equipped with a sensor array recording ice thickness and other physical parameters during trawling. We identified 2 environmental regimes, broadly coherent with the Nansen and Amundsen Basins. The Nansen Basin regime was distinguished from the Amundsen Basin regime by heavier sea-ice conditions, higher surface salinities and higher nitrate + nitrite concentrations. We found a diverse (28 species) under-ice community throughout the Eurasian Basin. Change in community structure reflected differences in the relative contribution of abundant species. Copepods (Calanus hyperboreus and C. glacialis) dominated in the Nansen Basin regime. In the Amundsen Basin regime, amphipods (Apherusa glacialis, Themisto libellula) dominated. Polar cod Boreogadus saida was present throughout the sampling area. Abrupt changes from a dominance of ice-associated amphipods at ice-covered stations to a dominance of pelagic amphipods (T. libellula) at nearby ice-free stations emphasised the decisive influence of sea ice on small-scale patterns in the surface-layer community. The observed response in community composition to different environmental regimes indicates potential long-term alterations in Arctic marine ecosystems as the Arctic Ocean continues to change.

Production and presence in the countries of Central America in Scopus on the theme of Documentation in Social Communication (1986-2013)

Describes and analyzes the results obtained after analysis of the publications present in Scopus data base and used that tool rankings generated by the research group Scimago on the production of the different countries of Central America on the issue of documentation the means of mass communication. Performed a comparative about different countries in the region and the scientific analyzes. Finally, and given and data analysis, a number of recommendations are made to improve the production and the presence in indexed database.

Enigmas monetarios en el derecho local. Los mencales y maravedís en los fueros castellanos

La historia de la moneda en la Castilla medieval ha estado siempre mediatizada por la convivencia no siempre armónica entre dos sistemas monetarios muy diferentes. Uno basado en la plata, de origen europeo, otro centrado en el oro, de raíces árabes. La necesidad de conectar y de establecer unas equivalencias entre ellos se convirtió pronto en una necesidad, máxime cuando las monedas de oro incrementaron sus variantes. En esta compleja situación aparecen mencales y maravedís citados conjuntamente en muchos fueros: Zorita, Uclés, Cuenca,... sin que su naturaleza quede del todo clara. Este artículo compara estas referencias y analiza las equivalencias que los unen. Como colofón al trabajo podemos afirmar que los maravedís citados en cada texto corresponden a monedas áureas de distinto peso y valor mientras el mencal es identificado con un ponderal de oro que los relaciona.

"Lancea", Lusitanian Word, and the "Lancienses" Ethnogenesis

Analysis of the word lancea, of Hispanic origin after Varro, and of place names, people´s names and personal names derived from it. It confirms that the spear was the most important weapon in the Bronze Age, belonging to the iuventus and used as heroic and divine symbol. This analysis confirms also the personality of the Lusitanians, a people related to the Celts but with more archaic archaeological, linguistic and cultural characteristics originated in the tradition of the Atlantic Bronze in the II millennium BC. It is also relevant to better know the organisation of Broze and Iron Age societies and the origin of Indo-Europeans peoples in Western Europe and of pre-Roman peoples of Iberia.

Cova dels Jurats at Calescoves (Alaior, Minorca). A Cave Shrine in the Talayotic context?

Excavations carried out in the Cova dels Jurats between 2010 and 2012 served to establish that, unlike the rest of the caves Calescoves, this one functioned as a sanctuary, with two different phases. The first one corresponds to the Final Talayotic Period, as the first cave shrine documented in the Talayotic culture. In Roman times, the place was still used as a sanctuary, but with a totally different ritual, linked to the inscriptions discovered at the entrance of the cave.

¿Fue la crisis política del Occidente musulmán del siglo XIII debida a un cambio climático? Una aproximación histórica al fin del Periodo Cálido Medieval

Durante el siglo XIII se produjo una sucesión de revueltas que supuso la desaparición del Imperio almohade y su sustitución por poderes regionales en al-Andalus, el Magreb y el Magreb al-Aqsà. La historiografía ha presentado el surgimiento y pugna entre estos poderes como un fenómeno social, político e, incluso, cultural y religioso, con el que se ha podido explicar su aniquilación o marginalización. Este trabajo pretende contextualizar los hechos desde una perspectiva medioambiental, de forma que la desintegración del califato almohade, el surgimiento de aquellos poderes y la progresión de los reinos cristianos en la península ibérica puedan entenderse desde una visión global de cambio climático y una posible crisis agrícola.

Agua y desarrollo urbano en la Castilla medieval: aportaciones a su estudio en la ciudad de Guadalajara

Uno de los elementos críticos del urbanismo castellano en la Edad Media era el acceso a recursos hídricos que pudieran servir para el abastecimiento humano. En función del clima, la orografía, y las infraestructuras heredadas de épocas anteriores, cada ciudad y villa del reino trató de buscar la mejor manera de asegurar el suministro de agua para sus vecinos. A lo largo de este trabajo se analiza la forma en la que el concejo de Guadalajara, así como los principales poderes religiosos y nobiliarios de la ciudad, fueron trazando la red de abastecimiento urbano durante la Baja Edad Media, a partir de las fuentes del paraje conocido como El Sotillo, y cómo realizaron la explotación económica del cauce del río Henares en las cercanías del municipio. El agua, bien escaso en la Alcarria, fue durante los siglos bajomedievales un elemento de gran importancia económica y símbolo de prestigio social, que despertó el interés de todos los grupos de la sociedad arriacense.