In Brief, August 2008


Scientists have made a DNA computer that puts bacteria to work solving a sorting problem (namely, one that involves flipping pancakes golden side up). The researchers modeled a simple two-pancake-flip problem using two DNA segments—one large and one short—and inserted them into the bacteria in random order and orientation. With the help of an enzyme, the segments would have a certain amount of time to flip to the correct position. Bacteria with the right answer were conveniently immune to antibiotics, which were used to wipe out those with incorrect answers. Because cells can reproduce, the number of microbial processors can increase exponentially to solve problems fast. —Nikhil Swaminathan


Scientists have pinpointed a star that flared in the ultraviolet (UV) portion of the spectrum for several hours before it blew apart. The finding represents the earliest visible sign of an imminent supernova. The UV rays result from a surge in temperature as an expanding internal shock wave strains to break free of the star; hence, they provide the last chance to collect data about the intact star before its destruction. The discovery comes shortly after researchers witnessed for the first time the x-rays that are released when the shock wave actually shreds the star. —JR Minkel


Damage to the cornea—the eye's clear, outermost part—is the second leading cause of blindness, affecting 10 million people worldwide, but cornea transplants are often unavailable because of donor shortages or cultural barriers. Now Stanford University researchers find that artificial corneas made from advanced materials could soon eliminate the need for donations altogether. Similar to soft contact lenses, the newest artificial corneas consist of water-swollen hydrogels that mimic the abilities of real corneas, such as allowing the diffusion of nutrients. Get a clear view from the June 6 Biotechnology Progress. —Charles Q. Choi

This article was originally published with the title "In Brief."

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