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This topological insulator, doped with chromium (Cr) atoms, conducts electricity on its surface and possesses desirable magnetic properties at a higher range of temperatures than before when sandwiched between magnetic materials known as ferromagnets. Credit: Natasha Hanacek/NIST

Traditional semiconductors like silicon are releasing their last new lines. Exotic materials called topological insulators (TIs) are on their way in. And when it comes to cool, nitrogen is the new helium. This was clearly on display in a novel experiment at the National Institute of Standards and Technology (NIST) that was performed by a multi-institutional collaboration including UCLA, NIST and the Beijing Institute of Technology in China.

Topological insulators are a new class of materials that were discovered l...

A photo of the PanSTARRS (Panoramic Survey Telescope & Rapid Response System) telescope in Hawaii. Astronomers have used a sky survey from this facility to identify a class of blue, hypervariable galaxies; the origin of the variability is uncertain but might in some cases be due to microlensing. Credit: PanSTARRS

Extreme variability in the intensity of the optical light of galaxies, by factors of 2 or more, is of great interest to astronomers. It can flag the presence of rare types of supernovae, for example, or spot sudden accretion activity around quiescent black holes or around the supermassive black hole at the galaxy’s nucleus. In recent years systematic searches for such variability have been made using instruments that can survey wide swaths of the sky...

Saturn’s largest moon, Titan, has features that resemble Earth’s geology, with deep, steep-sided canyons. Credit: Cassini/NASA/JPL

Although Saturn’s largest moon, Titan, is surrounded by a thick, hazy atmosphere, Cornell astronomers have revealed that the moon’s terrain features deep, steep-sided canyons filled with liquid hydrocarbons. While NASA’s Cassini mission previously had imaged the channels flowing into the large northern sea Ligeia Mare, the new observations used the Cassini radar’s altimetry mode to measure their topography. The surprising results showed canyons hundreds of feet deep featuring specular reflections from the channel floors, the first direct evidence that they are currently filled with liquid.

“Earth is warm and rocky, with rivers of water, while Titan is cold and ...

The first transplantation of stem cells in patients with Parkinson’s disease is almost within reach. However, it remains a challenge for researchers to control stem cells accurately in the lab in order to achieve successful and functional stem cell therapies for patients. “In our preclinical assessments of stem cell-derived dopamine neurons we noticed that the outcome in animal models varied dramatically, even though the cells were very similar at the time of transplantation. This has been frustrating and puzzling, and has significantly delayed the establishment of clinical cell production protocols,” says Malin Parmar, who led the study conducted at Lund University as part of the EU network NeuroStemcellRepair.

The Lund experiments use modern global gene expression studies to better unde...