Two-dimensional dopant layers (δ-layers) in semiconductors provide the high-mobility electron liquids (2DELs) needed for nanoscale quantum-electronic devices. Key parameters such as carrier densities, effective masses, and confinement thicknesses for 2DELs have traditionally been extracted from quantum magnetotransport. In principle, the parameters are immediately readable from the one-electron spectral function that can be measured by angle-resolved photoemission spectroscopy (ARPES).
View Article and Find Full Text PDFA breeding colony of notothenioid icefish (Neopagetopsis ionah, Nybelin 1947) of globally unprecedented extent has been discovered in the southern Weddell Sea, Antarctica. The colony was estimated to cover at least ∼240 km of the eastern flank of the Filchner Trough, comprised of fish nests at a density of 0.26 nests per square meter, representing an estimated total of ∼60 million active nests and associated fish biomass of >60,000 tonnes.
View Article and Find Full Text PDFSouthern Ocean ecosystems are under pressure from resource exploitation and climate change. Mitigation requires the identification and protection of Areas of Ecological Significance (AESs), which have so far not been determined at the ocean-basin scale. Here, using assemblage-level tracking of marine predators, we identify AESs for this globally important region and assess current threats and protection levels.
View Article and Find Full Text PDFBackground: Medical therapy, the cornerstone of managing epilepsy, still fails a substantial portion of patients. Little information is available regarding the potential impact of different bispectral index (BIS) levels on electrocorticographic spike identification for surgical epileptic foci resection.
Methods: Twenty-two intractable epilepsy subjects were randomly allocated to the propofol-remifentanil or sevoflurane-remifentanil groups, and were further randomized to four BIS85 (BIS 71-85), BIS70 (BIS 56-70), BIS55 (BIS 41-55), and BIS40 (BIS ≤40) sequence order.