Downscaling Meteosat Land Surface Temperature over a Heterogeneous Landscape Using a Data Assimilation Approach

International audienceA wide range of environmental applications require the monitoring of land surface temperature (LST) at frequent intervals and fine spatial resolutions, but these conditions are not offered nowadays by the available space sensors. To overcome these shortcomings, LST downscaling methods have been developed to derive higher resolution LST from the available satellite data. This research concerns the application of a data assimilation (DA) downscaling approach, the genetic particle smoother (GPS), to disaggregate Meteosat 8 LST time series (3 km × 5 km) at finer spatial resolutions. The methodology was applied over the Crau-Camargue region in Southeastern France for seven months in 2009. The evaluation of the downscaled LSTs has been performed at a moderate resolution using a set of coincident clear-sky MODIS LST images from Aqua and Terra platforms (1 km × 1 km) and at a higher resolution using Landsat 7 data (60 m × 60 m). The performance of the downscaling has been assessed in terms of reduction of the biases and the root mean square errors (RMSE) compared to prior model-simulated LSTs. The results showed that GPS allows downscaling the Meteosat LST product from 3 × 5 km2 to 1 × 1 km2 scales with a RMSE less than 2.7 K. Finer scale downscaling at Landsat 7 resolution showed larger errors (RMSE around 5 K) explained by land cover errors and inter-calibration issues between sensors. Further methodology improvements are finally suggeste

Identification of Outer Membrane Proteins Altered in Response to UVC-Radiation in Vibrio parahaemolyticus and Vibrio alginolyticus.

International audienceVibrio parahaemolyticus and V. alginolyticus, marine foodborne pathogens, were treated with UVC-radiation (240 J/m(2)) to evaluate alterations in their outer membrane protein profiles. Outer membrane protein patterns of UVC-irradiated bacteria were found altered when analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis. Altered proteins were identified by mass spectrometry (MS and MS/MS) and analysis revealed that OmpW, OmpA, Long-chain fatty acid transport protein, Outer membrane receptor protein, Putative uncharacterized protein VP0167, Maltoporin (lamB), Polar flagellin B/D, Agglutination protein Peptidoglycan-associated lipoprotein and MltA-interacting protein MipA were appeared, thereby they can be considered as UVC-stress proteins in some vibrios. In addition, expression of OmpK decreased to non-detectable level. Furthermore, we observed a decrease or an increase in the expression level of other outer membrane proteins

Identification of outer membrane proteins of Vibrio parahaemolyticus and Vibrio alginolyticus altered in response to γ-irradiation or long-term starvation.

International audienceVibrio parahaemolyticus and Vibrio alginolyticus were subjected to γ-irradiation (0.5 kGy) or starvation by incubation for 8 months in seawater to study modifications in their outer membrane protein patterns. After treatment, outer membrane protein profiles of starved or γ-irradiated bacteria were found to be altered when analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Altered proteins were identified by mass spectrometry (MS and MS/MS) and analyses revealed that OmpU can be considered a starvation stress-induced protein. In addition, expression of OtnA, OmpW, OmpA and peptidoglycan-associated lipoprotein decreased to non-detectable levels in starved cells. Furthermore, MltA-interacting protein MipA appeared under γ-irradiation or starvation conditions. Thus, it can be considered to be a γ-irradiation, long-term starvation stress protein in some vibrios