The Earth: Plasma Sources, Losses, and Transport Processes

This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et al., Magnetospheric Plasma Sources and Losses, 1999) are addressed

The neuronal S100B protein is a calcium-tuned suppressor of amyloid-beta aggregation.

Amyloid-beta (A beta) aggregation and neuroinflammation are consistent features in Alzheimer's disease (AD) and strong candidates for the initiation of neurodegeneration. S100B is one of the most abundant proinflammatory proteins that is chronically up-regulated in AD and is found associated with senile plaques. This recognized biomarker for brain distress may, thus, play roles in amyloid aggregation which remain to be determined. We report a novel role for the neuronal S100B protein as suppressor of A beta 42 aggregation and toxicity. We determined the structural details of the interaction between monomeric A beta 42 and S100B, which is favored by calcium binding to S100B, possibly involving conformational switching of disordered A beta 42 into an alpha-helical conformer, which locks aggregation. From nuclear magnetic resonance experiments, we show that this dynamic interaction occurs at a promiscuous peptide-binding region within the interfacial cleft of the S100B homodimer. This physical interaction is coupled to a functional role in the inhibition of A beta 42 aggregation and toxicity and is tuned by calcium binding to S100B. S100B delays the onset of A beta 42 aggregation by interacting with A beta 42 monomers inhibiting primary nucleation, and the calcium-bound state substantially affects secondary nucleation by inhibiting fibril surface-catalyzed reactions through S100B binding to growing A beta 42 oligomers and fibrils. S100B protects cells from A beta 42-mediated toxicity, rescuing cell viability and decreasing apoptosis induced by A beta 42 in cell cultures. Together, our findings suggest that molecular targeting of S100B could be translated into development of novel approaches to ameliorate AD neurodegeneration

A unified cropland layer at 250 m for global agriculture monitoring

Accurate and timely information on the global cropland extent is critical for food security monitoring, water management and earth system modeling. Principally, it allows for analyzing satellite image time-series to assess the crop conditions and permits isolation of the agricultural component to focus on food security and impacts of various climatic scenarios. However, despite its critical importance, accurate information on the spatial extent, cropland mapping with remote sensing imagery remains a major challenge. Following an exhaustive identification and collection of existing land cover maps, a multi-criteria analysis was designed at the country level to evaluate the fitness of a cropland map with regards to four dimensions: its timeliness, its legend, its resolution adequacy and its confidence level. As a result, a Unified Cropland Layer that combines the fittest products into a 250 m global cropland map was assembled. With an evaluated accuracy ranging from 82% to 95%, the Unified Cropland Layer successfully improved the accuracy compared to single global products.Data Set: https://dx.doi.org/10.6084/m9.figshare.2066742 or http://maps.elie.ucl.ac.b