Mapping global cropland and field size

A new 1 km global IIASA-IFPRI cropland percentage map for the baseline year 2005 has been developed which integrates a number of individual cropland maps at global to regional to national scales. The individual map products include existing global land cover maps such as GlobCover 2005 and MODIS v.5, regional maps such as AFRICOVER and national maps from mapping agencies and other organizations. The different products are ranked at the national level using crowdsourced data from Geo-Wiki to create a map that reflects the likelihood of cropland. Calibration with national and subnational crop statistics was then undertaken to distribute the cropland within each country and subnational unit. The new IIASA-IFPRI cropland product has been validated using very high-resolution satellite imagery via Geo-Wiki and has an overall accuracy of 82.4%. It has also been compared with the EarthStat cropland product and shows a lower root mean square error on an independent data set collected from Geo-Wiki. The first ever global field size map was produced at the same resolution as the IIASA-IFPRI cropland map based on interpolation of field size data collected via a Geo-Wiki crowdsourcing campaign. A validation exercise of the global field size map revealed satisfactory agreement with control data, particularly given the relatively modest size of the field size data set used to create the map. Both are critical inputs to global agricultural monitoring in the frame of GEOGLAM and will serve the global land modelling and integrated assessment community, in particular for improving land use models that require baseline cropland information. These products are freely available for downloading from the http://cropland.geo-wiki.org website.

[A new case of relapsing hemolytic and uremic syndrome]

Relapsing hemolytic and uremic syndrome is infrequent in pediatric patients. The case of an infant who had HUS at 11 months of age and subsequently developed two relapses at 3 years and 3 1/2 years of age is reported. Outcome of the first episode was favorable, with no elements suggesting an increased risk for subsequent relapses. Conversely, the second and third episodes were followed by gradual deterioration of renal function and persistence of severe arterial hypertension. To clarify the epidemiology, clinical manifestations, histology, and outcome of HUS, the 24 pediatric cases of relapsing HUS reported in the English-language medical literature were reviewed. In this group, mean age at onset was 4 years 1 month (range 4 months-9 years) and number of relapses ranged from 1 to 14. Evidence of microangiopathy was the most common histologic finding (15/22) but non-specific lesions were seen in some instances. Opinions vary as to the prognosis of relapsing HUS; our case suggests that relapses are of adverse prognostic significance.