Stable water isotope patterns in a climate change hotspot: The isotope hydrology framework of Corsica (western Mediterranean)

International audienceThe Mediterranean is regarded as a region of intense climate change. To better understand future climate change, this area has been the target of several palaeoclimate studies which also studied stable isotope proxies that are directly linked to the stable isotope composition of water, such as tree rings, tooth enamel or speleothems. For such work, it is also essential to establish an isotope hydrology framework of the region of interest. Surface waters from streams and lakes as well as groundwater from springs on the island of Corsica were sampled between 2003 and 2009 for their oxygen and hydrogen isotope compositions. Isotope values from lake waters were enriched in heavier isotopes and define a local evaporation line (LEL). On the other hand, stream and spring waters reflect the isotope composition of local precipitation in the catchment. The intersection of the LEL and the linear fit of the spring and stream waters reflect the mean isotope composition of the annual precipitation (δP) with values of-8.6(±0.2) ‰ for δ18O and-58(±2) ‰ for δ2H. This value is also a good indicator of the average isotope composition of the local groundwater in the island. Surface water samples reflect the altitude isotope effect with a value of-0.17(±0.02) ‰ per 100 m elevation for oxygen isotopes. At Vizzavona Pass in central Corsica, water samples from two catchments within a lateral distance of only a few hundred metres showed unexpected but systematic differences in their stable isotope composition. At this specific location, the direction of exposure seems to be an important factor. The differences were likely caused by isotopic enrichment during recharge in warm weather conditions in south-exposed valley flanks compared to the opposite, north-exposed valley flanks.</p

Field-based stable isotope analysis of carbon dioxide by mid-infrared laser spectroscopy for carbon capture and storage monitoring

A newly developed isotope ratio laser spectrometer for CO2 analyses has been tested during a tracer experiment at the Ketzin pilot site (northern Germany) for CO2 storage. For the experiment, 500 tons of CO2 from a natural CO2 reservoir was injected in supercritical state into the reservoir. The carbon stable isotope value (δ13C) of injected CO2 was significantly different from background values. In order to observe the breakthrough of the isotope tracer continuously, the new instruments were connected to a stainless steel riser tube that was installed in an observation well. The laser instrument is based on tunable laser direct absorption in the mid-infrared. The instrument recorded a continuous 10 day carbon stable isotope data set with 30 min resolution directly on-site in a field-based laboratory container during a tracer experiment. To test the instruments performance and accuracy the monitoring campaign was accompanied by daily CO2 sampling for laboratory analyses with isotope ratio mass spectrometry (IRMS). The carbon stable isotope ratios measured by conventional IRMS technique and by the new mid-infrared laser spectrometer agree remarkably well within analytical precision. This proves the capability of the new midinfrared direct absorption technique to measure high precision and accurate real-time stable isotope data directly in the field. The laser spectroscopy data revealed for the first time a prior to this experiment unknown, intensive dynamic with fast changing δ13C values. The arrival pattern of the tracer suggest that the observed fluctuations were probably caused by migration along separate and distinct preferential flow paths between injection well and observation well. The short-term variances as observed in this study might have been missed during previous works that applied laboratory-based IRMS analysis. The new technique could contribute to a better tracing of the migration of the underground CO2 plume and help to ensure the long-term integrity of the reservoir

Introduction: spiritual landscapes of Southeast Asia

This Introduction foreshadows the main themes of this special issue on spiritual landscapes of Southeast Asia. Throughout Southeast Asia, links exist between spirit beings or potent energies and particular sites in the landscape, including trees, mountains and rivers. These are highlighted in this collection of papers via the notion of 'spiritual landscapes'. This concept also broadens anthropological approaches to the religious significance of the landscape, by problematising the separation of 'natural' and 'cultural' environments while sidestepping the implication that something called 'sacred geography' can be separated from the pragmatic activities of daily life. Following an ethnographic overview of spirit-places and environmental forces in the region, I discuss our need to take more seriously the claims of many Southeast Asian people that their landscapes have agency. In the context of religious conversion, the agency of the landscape often becomes a central concern, as reformers and missionaries seek to 'purify' the environment of such spiritual power. However, in addition to 'purification', ongoing conversion may also involve new forms of conversation with the landscape, including re-enchantments, religious syntheses or reassertions of the landscape's potency

Brain pathology of a patient 7years after autologous hematopoietic stem cell transplantation for multiple sclerosis.

Aggressive immunosuppression followed by autologous hematopoietic stem cell transplantation (aHSCT) can be an effective treatment for severe multiple sclerosis (MS), but not all stages of disease may benefit equally. The case of a 49-year-old woman with advanced secondary-progressive MS whose clinical course was not improved by aHSCT and who seven years after transplantation succumbed to complications of severe MS disease-related disability is presented. Autopsy findings of ongoing neurodegeneration despite only rare infiltrating T-lymphocytes illustrate that late MS disease may not represent a suitable disease stage for aHSCT

Selection and optimization of hits from a high-throughput phenotypic screen againstTrypanosoma cruzi

Background: Inhibitors of Trypanosoma cruzi with novel mechanisms of action are urgently required to diversify the current clinical and preclinical pipelines. Increasing the number and diversity of hits available for assessment at the beginning of the discovery process will help to achieve this aim. Results: We report the evaluation of multiple hits generated from a high-throughput screen to identify inhibitors of T. cruzi and from these studies the discovery of two novel series currently in lead optimization. Lead compounds from these series potently and selectively inhibit growth of T. cruzi in vitro and the most advanced compound is orally active in a subchronic mouse model of T. cruzi infection. Conclusion: High-throughput screening of novel compound collections has an important role to play in diversifying the trypanosomatid drug discovery portfolio. A new T. cruzi inhibitor series with good drug-like properties and promising in vivo efficacy has been identified through this process