ABSTRACT
Large-scale land cover classification from satellite imagery is still a challenge due to the big volume of data to be processed, to persistent cloud-cover in cloud-prone areas as well as seasonal artefacts that affect spatial homogeneity. Sentinel-2 times series from Copernicus Earth Observation program offer a great potential for fine scale land cover mapping thanks to high spatial and temporal resolutions, with a decametric resolution and five-day repeat time. However, the selection of best available scenes, their download together with the requirements in terms of storage and computing resources pose restrictions for large-scale land cover mapping. The dataset presented in this paper corresponds to global cloud-free pixel based composite created from the Sentinel-2 data archive (Level L1C) available in Google Earth Engine for the period January 2017- December 2018. The methodology used for generating the image composite is described and the metadata associated with the 10 m resolution dataset is presented. The data with a total volume of 15 TB is stored on the Big Data platform of the Joint Research Centre. It can be downloaded per UTM grid zone, loaded into GIS clients and displayed easily thanks to pre-computed overviews.
ABSTRACT
The case records of 471 patients with massive transfusions of ten or more units of bank blood within 24 hours were reviewed to analyze the electrolyte and acid-base changes. The patients who lived had a less severe acidosis (7.23 +/- 0.15 vs 7.11 +/- 0.17) and the HCO3 was higher (19.8 +/- 15.2 vs 13.4 +/- 6.8) (P less than 0.001). The mean anion gap, despite the low HCO3, was 11.8 +/- 7.8 mEq/L. A combined metabolic and respiratory acidosis, often following bicarbonate therapy, was fetal in 83 per cent (39/47). Serum potassium values (K) were high in 22 per cent and low in 18 per cent of patients. If potassium levels were "corrected" by subtracting 0.5 mEq/L for each 0.1 pH of metabolic acidosis, only 5 per cent of patients were hyperkalemic. Patients dying within 48 hours of the massive transfusions had higher potassium levels (4.9 +/- 1.1 vs 4.4 +/- 0.9; P less than 0.001). Ionized calcium levels (Ca++) were less than normal (1.13-1.32 mmol/L) in 94 per cent of patients and were very low (less than 0.70 mmol/L) in 46 per cent (108/234). The mortality rate with severe ionic hypocalcemia was 71 per cent (vs 40% in patients with more normal values); P less than 0.0001. pH, PCO2, K, and Ca++ must be followed closely with massive transfusions. Rapid correction of volume and pH, without overcorrection, is essential.