DNA arrays change shape in response to an external trigger. Credit: Yonggang Ke

They look like security gates, but change shape in a cascade. Biomedical engineers have built simple machines out of DNA, consisting of arrays whose units switch reversibly between two different shapes. The arrays’ inventors say they could be harnessed to make nanotech sensors or amplifiers. Potentially, they could be combined to form logic gates, the parts of a molecular computer. The DNA machines can relay discrete bits of information through space or amplify a signal, says Yonggang Ke, PhD, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory.

“In the field of DNA-based computing, the DNA contains the information, but the molecules are floating aroun...

1. A yet to be discovered, unseen “planetary mass object” makes its existence known by ruffling the orbital plane of distant Kuiper Belt objects, according to research by Kat Volk and Renu Malhotra of the UA’s Lunar and Planetary Laboratory. The object is pictured on a wide orbit far beyond Pluto in this artist’s illustration. (Image: Heather Roper/LPL)
2. A planetary mass object the size of Mars would be sufficient to produce the observed perturbations in the distant Kuiper Belt.
Credit: Heather Roper/LPL

An unknown, unseen “planetary mass object” may lurk in the outer reaches of our solar system, according to new research on the orbits of minor planets. This object would be different from – and much closer than – the so-called Planet Nine, a planet whose existence yet awaits confirmation...

At any given moment, as many as 10 million wild jets of solar material burst from the sun’s surface. They erupt as fast as 60 miles per second, and can reach lengths of 6,000 miles before collapsing. These are spicules, and despite their grass-like abundance, scientists didn’t understand how they form. Now, for the first time, a computer simulation — so detailed it took a full year to run — shows how spicules form, helping scientists understand how spicules can break free of the sun’s surface and surge upward so quickly. Credit: NASA’s Goddard Space Flight Center

For the first time, a computer simulation – so detailed it took a full year to run – shows how spicules form, helping scientists understand how spicules can break free of the sun’s surface and surge upward so quickly...

Two Aplysia sensory neurons with synaptic contacts on the same motor neuron in culture after isolation from the nervous system of Aplysia. The motor neuron has been injected with a fluorescent molecule that blocks the activity of a specific Protein Kinase M molecule. Credit: Schacher Lab/Columbia University Medical Center

Different types of memories stored in the same neuron of the marine snail Aplysia can be selectively erased, according to a new study by researchers at Columbia University Medical Center (CUMC) and McGill University. The findings suggest that it may be possible to develop drugs to delete memories that trigger anxiety and post-traumatic stress disorder (PTSD) without affecting other important memories of past events.
During emotional or traumatic events, multiple memories ...