Monitoring of river contamination derived from acid mine drainage using airborne imaging spectroscopy (HyMap data, South-West Spain)

Imaging spectroscopy is used in this work as an essential mapping tool to monitor changes in contaminated river sediments. Multidate hyperspectral image data (HyMap) are utilized to identify spatial mineral patterns, to detect temporal changes in mineralogy and to link these changes with geochemical processes and short-term climate characteristics. River sediments contaminated by acid mine drainage are covered by crusts with variably hydrated iron sulphate. The mineralogy of the crusts and the grain size of the underlying fluvial sediments overlap. The spectra used to build up maps from HyMap data are diagnosed mineralogically with archive spectral libraries from pyrite oxidation minerals from well-known sequences of minerals. The maps compiled from hyperspectral imagery display generalized oxidation shown by the coatings over river sediments following warm and dry periods with low water level. After the wet periods, the area covered by oxidized mineralogical phases recedes in favour of hydrated sulphate. The iteration of image processing algorithms and the mineralogical and potential contamination in a geological context are described. Change detection of the mineral crusts on the river sediments by mapping using hyperspectral remote sensing data may thus enable a quantitative and qualitative environmental evaluation by the regulators

Distance, globalization, and international trade

For a long time globalization could be seen everywhere but in gravity estimates. We offer evidence how globalization affects manufacturing trade over the period 1986-2006 and show that, on average, the effect of distance has fallen whereas the effects of proximity and regional trade agreements have increased over time. We also document substantial cross-country heterogeneity in the extent to which distance elasticities have changed. Countries in the middle of the per-capita income distribution have seen the steepest fall in distance coeffcients. At the same time, distance as a trade friction has not lost its bite for a number of low income countries, which may jeopardize their integration into global markets. We present suggestive evidence that the heterogeneous change in distance elasticities is related to secular shifts in the composition of exports

Mapping marine and fluvial salt crusts in estuaries collecting acid water using hyperspectral Hyperion imagery (Marshes of the river Odiel, Huelva)

Revista oficial de la Asociación Española de Teledetección[EN] Temporal monitoring of salt efflorescence on the marshes at the mouth of the river Odiel (Huelva) is made using hyperspectral archive Hyperion data. Climate variability estimations are made based on well-known spectral features related to vegetation and shallow water, using archive spectral libraries. The observations point to spectral and geomorphological indicators which can be monitored through image processing supported by field and laboratory spectral data, on a repeatable basis. Mapping a larger sequence of images under different climate regime and wider tidal range, would improve the estimation of spectral features to ensure a routine monitoring of salt crusts with hyperspectral data.[ES] Se realiza un seguimiento temporal de eflorescencias salinas en las Marismas del río Odiel, que ocupan el estuario en su desembocadura, con imágenes hiperespectrales Hyperion de archivo. A partir de varias cartografías elaboradas con tratamiento de imágenes, se han realizado estimaciones de variabilidad climática basadas en series minerales conocidas, utilizando respuestas espectrales típicas en vegetación y aguas someras. En este trabajo, se esbozan indicadores espectrales y geomorfológicos susceptibles de un seguimiento repetible con tratamiento de imágenes en las marismas, que permita cuantificar cambios climáticos combinados con la influencia de las mareas, enfocados a estudiar la evolución de las costras salinas que aparecen sobre la superficie de los sedimentos, al retirarse la vegetación y la lámina de agua. En este marco, se presentan cartografías elaboradas a partir de imágenes Hyperion en varias fechas. Se describe el tratamiento preinterpretativo de las imágenes Hyperion, y la secuencia de algoritmos que permiten elaborar las cartografías de sustancias salinas en zonas intermareales. El análisis de una secuencia más amplia de imágenes con condiciones climatológicas distintas, y más amplitud de oscilación mareal, enriquecerá la estimación de parámetros espectrales para el seguimiento rutinario de costras salinas con datos hiperespectrales.Los datos Hyperion y la metodología de trabajo para la cartografía con datos hiperespectrales se desarrollaron durante la subvención CGL2007- 60004/CLI. Las bases para comenzar este trabajo surgieron durante la tesis doctoral de Jorge Buzzi Marcos (BES-2008-003648).Riaza, A.; García-Meléndez, E.; Carrère, V.; Mueller, A. (2014). Cartografía de sales marinas y fluviales en estuarios receptores de aguas ácidas con imágenes hiperespectrales Hyperion (Marismas del río Odiel, Huelva). Revista de Teledetección. (41):1-7. https://doi.org/10.4995/raet.2014.2255SWORD1741BELLUCO, E., CAMUFFO, M., FERRARI, S., MODENESE, L., SILVESTRI, S., MARANI, A., & MARANI, M. (2006). Mapping salt-marsh vegetation by multispectral and hyperspectral remote sensing. Remote Sensing of Environment, 105(1), 54-67. doi:10.1016/j.rse.2006.06.006Buzzi, J., 2012. Imaging spectroscopy to evaluate the contamination from sulphide mine waste in the Iberian Pyrite Belt using hyperspectral sensors (Huelva, Spain), Tesis Doctoral Universidad de León, 212 p.Jupp, D.L.B., 2001. Discussion around Hyperion Data. CSIRO Office of Space Science Applications, Earth Observation Centre: 1-9.RSI, 2000. ENVI User’s Guide. Research Systems Inc. Publications

NS2 Protein of Hepatitis C Virus Interacts with Structural and Non-Structural Proteins towards Virus Assembly

Growing experimental evidence indicates that, in addition to the physical virion components, the non-structural proteins of hepatitis C virus (HCV) are intimately involved in orchestrating morphogenesis. Since it is dispensable for HCV RNA replication, the non-structural viral protein NS2 is suggested to play a central role in HCV particle assembly. However, despite genetic evidences, we have almost no understanding about NS2 protein-protein interactions and their role in the production of infectious particles. Here, we used co-immunoprecipitation and/or fluorescence resonance energy transfer with fluorescence lifetime imaging microscopy analyses to study the interactions between NS2 and the viroporin p7 and the HCV glycoprotein E2. In addition, we used alanine scanning insertion mutagenesis as well as other mutations in the context of an infectious virus to investigate the functional role of NS2 in HCV assembly. Finally, the subcellular localization of NS2 and several mutants was analyzed by confocal microscopy. Our data demonstrate molecular interactions between NS2 and p7 and E2. Furthermore, we show that, in the context of an infectious virus, NS2 accumulates over time in endoplasmic reticulum-derived dotted structures and colocalizes with both the envelope glycoproteins and components of the replication complex in close proximity to the HCV core protein and lipid droplets, a location that has been shown to be essential for virus assembly. We show that NS2 transmembrane region is crucial for both E2 interaction and subcellular localization. Moreover, specific mutations in core, envelope proteins, p7 and NS5A reported to abolish viral assembly changed the subcellular localization of NS2 protein. Together, these observations indicate that NS2 protein attracts the envelope proteins at the assembly site and it crosstalks with non-structural proteins for virus assembly