iPhone app lets the blind see through the crowd’s eyes

Using an iPhone app called VizWiz, the blind can now receive realtime assistance from sighted workers on Amazon’s Mechanical Turk service.

With the app, blind users use their phone to take a picture of something they want identified, have it sent automatically to a recruited worker on the Internet, and receive back an answer, all within an average time of 27 seconds. Yasmina, a student at the University of Rochester, used the app to identify a can of coconut milk amongst other canned goods.

During a volunteer test session, participants asked questions like “What denomination is this bill?,” “Do you see picnic tables across the parking lot?,” and “What temperature is my oven set to?”

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Lasers Made from Human Cells

Living cell with green fluorescent protein

A laser based on living cells has been created by researchers at Harvard Medical School and the Massachusetts General Hospital in Boston.Living lasers have a few basic parts that are drawn from the same list as any laser. First, the researchers genetically modified human liver cells so that they produce large amounts of green fluorescent proteins that are scattered throughout the cell. A cell carrying these proteins acts as the "gain medium"—the part of the laser that amplifies light energy.

Like any laser, the cell laser needs an energy source to "pump" it and increase the power of the light it can emit. The researchers pumped the living lasers by pulsing the cells with light through a microscope. As light bounces around inside the cell and is re-emitted by the fluorescent proteins, it's amplified, increasing in power before being emitted in a coherent beam. To keep the light bouncing around as long as possible, to gain as much power as possible, the Boston group placed these cells inside a biocompatible optical cavity—essentially a tiny, highly reflective, cell-shaped hole.

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