Molecules/Matter & Energy

A first look at the roots of sight, plus fading blues, steady birds and more in this week’s news

Seeing rods in the eye
Rods in healthy human eyes have been imaged for the first time, thanks to technology borrowed from telescopes. These tiny light-sensitive cells are difficult to spot because the human eye distorts light, much as the Earth’s atmosphere does. But adaptive optics — laser beams like those that help astronomers measure and compensate for these distortions — cleared things up for a team led by Alfredo Dubra Suarez of the University of Rochester. Being able to routinely monitor rods could help doctors better understand night blindness, retinitis pigmentosa and other degenerative diseases, the researchers report in the July 1 Biomedical Optics Express.Devin Powell

Secret to birds’ steady gaze
Some birds may keep their gaze steady while hovering by rotating their bodies around their eyes. When a Japanese white-eye pushes its wings downward, the forces created rotate the entire bird forward, lowering the eyes just enough to counteract the upwards jerk of the body. This keeps the eyes still, as revealed in high-speed videos of several birds showing air flow beneath the wings. Other research has suggested that the neck and brain also play a role in adjusting the eyes. This new aerodynamic trick could be useful in stabilizing manmade fliers, physicists at National Taiwan University report in an upcoming Physical Review E.Devin Powell

Paintings lose the blues
A rich blue pigment’s propensity to fade to gray has finally been explained by chemists, hundreds of years after the pigment’s heyday. From the 16th to 18th centuries, artists intensified their blues with smalt, usually a combination of potassium, silicon, and cobalt. Potassium leaching from the pigment was implicated in the eventual discoloration, but the chemistry wasn’t clear. Now investigations by researchers in France and England of several art works from the Louvre and London’s National Gallery reveal that when potassium departs, cobalt atoms lose their stability and no longer can keep themselves in a structural arrangement that reflects vibrant blue. The work is reported in an upcoming Analytical Chemistry. —Rachel Ehrenberg

Bones bared with light
By taking advantage of a protein’s fondness for bone, scientists have created a fluorescent tag that binds to and reveals skeletal structures in great detail, experiments in mice reveal. The new seek-and-glow tag, described online June 9 in ChemBioChem, is derived from a natural bone-binding protein called osteocalcin that seeks and sticks to hydroxyapatite, the main component of bone. The new tag could help researchers detect calcification in arteries or breast tissue and track the progression of bone diseases, say scientists from the Methodist Hospital Research Institute in Houston. —Rachel Ehrenberg

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