Measurements of metastable helium in Earth's atmosphere by resonance lidar.

Monitoring and predicting space weather activity is increasingly important given society's growing reliance on space-based infrastructure but is hampered by a lack of observational data. Airglow at 1083 nm from metastable helium He(2S) in the thermosphere has long been a target for remote-sensing instruments seeking to fill that gap; however, passive measurements of He(2S) fluorescence are limited by low brightness, and interpretation of these observations is complicated by the > 500 km depth of the He(2S) layer. Here, we demonstrate a lidar instrument that is able to stimulate and detect He(2S) fluorescence, and we present measured profiles of He(2S) density.

The metal binding abilities of Megathura crenulata metallothionein (McMT) in the frame of gastropoda MTs.

Metallothioneins (MTs) are proteins that play a major role in metal homeostasis and/or detoxification in all kind of organisms. The MT gene/protein system of gastropod molluscs provides an invaluable model to study the diversification mechanisms that have enabled MTs to achieve metal-binding specificity through evolution. Most pulmonate gastropods, particularly terrestrial snails, harbor three paralogous isogenes encoding three MT isoforms with different metal binding preferences: the highly specific CdMT and CuMT isoforms, for cadmium and copper respectively, and the unspecific Cd/CuMT isoform.