Category: Techie

Chinese leaders have fired three government officials involved in a study of genetically modified rice, after complaints that the study’s subjects weren’t properly informed. The subjects were kids whose parents didn’t know what their kids were eating.

The study involves golden rice, a goldenrod-colored form of the grain developed more than a decade ago for the express purpose of addressing vitamin A deficiency in developing countries. It has been alternately hailed as a humanitarian breakthrough and denigrated as an empty promise to the poor–but one thing it has not been is actually approved for use. The study at the heart of this new controversy was a step on that path. It was partially funded by the U.S. Department of Agriculture and included some U.S.-based researchers.

In the study, some Chinese children were fed golden rice, which had been genetically modified to produce beta carotene, a precursor to vitamin A formation. Other children in the study ate meals containing spinach or beta carotene capsules. Scientists wanted to determine how well the beta carotene converted to vitamin A after the rice was eaten. Parents were told their kids were eating rice that contained beta carotene, but they weren’t told it got this way through genetic modification. They were also not told about skepticism and controversy surrounding GMO foods generally and golden rice specifically.

Greenpeace pointed out this study back in August, and Chinese officials launched an investigation, culminating in a recent report about the trial on state-run TV station CCTV. In the program, Chinese officials admit that they didn’t mention golden rice because it was “too sensitive,” and that they wanted to save time and move the study forward. Now families are outraged, reports Nature News, which covers the controversy in depth. And three Chinese officials have been fired.

Most of the food we eat in this country contains some ingredients from genetically modified plants, whether it’s weed-killer-resistant soybeans or pest-resistant corn, and most people don’t know it–so it’s in some ways this isn’t all that shocking. But genetically modified food is met with more skepticism in China than it is generally in the U.S.

What’s really at issue here is informed consent, a serious matter in any scientific study. People need to understand what they’re volunteering to do–or volunteering their kids to do–especially when it involves ingesting something.

[Nature News]

A new silicon microchip can do what no other silicon microchip could before, generating and transmitting radio waves in the terahertz range. The tiny chip operates at 300 times the speed of the CMOS chip in your smartphone, and could someday be used to peer through walls, inside containers and into the food supply.

It can see a knife hidden inside a teddy bear, like the image above. It can even determine the fat content of a piece of chicken, apparently.

Terahertz scanners have long been touted as the future of security–electromagnetic waves in that frequency range can penetrate where other forms of radiation cannot, but they don’t produce the damaging ionizing radiation of X-rays. T-rays can sense every molecule, so they could theoretically detect illicit drugs or explosives, or even hunt for cancer cells. They can see through walls and inside objects, so they would be useful security screeners. The problem has been that the scanners are huge, requiring lasers and many lenses to focus light, not to mention cooling equipment to keep everything at operating temperatures.

For that reason, electrical engineers have been trying to build terahertz scanners using common and cheap manufacturing processes, especially the complementary metal-oxide semiconductors that power most consumer devices. Earlier this year, researchers at the University of Texas at Dallas figured out how to build a special type of high-speed diode in CMOS, producing T-rays on a small scale. Now some researchers at Caltech have done one better, producing the world’s first integrated T-ray arrays.

The mere fact that it operates at terahertz frequencies is a breakthrough. No standard transistors can amplify a radio signal in that range. Silicon chips aren’t designed to operate in it. To get around those limitations, electrical engineering professor Ali Hajimiri and postdoc Kaushik Sengupta combined several transistors on one array, all operating in unison. When operating at the right frequencies, the transistors’ collective power can be combined, boosting the signal’s strength. In a Caltech news release, Hajimiri compared it to an army of ants hefting the same load as one elephant. “Nowadays we can make a very large number of transistors that individually are not very powerful, but when combined and working in unison, can do a lot more,” he said.

What’s more, they figured out how to get the entire chip to operate as an antenna, incorporating several pieces of metal instead of a single wire. (A wire wouldn’t work at terahertz frequencies.) The result is a chip-scale scanner that can produce and distribute T-rays. IBM helped produce the chip, according to Caltech. Hajimiri and Sengupta describe their new chip in the December issue of IEEE Journal of Solid-State Circuits.

[Caltech]

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Linus Torvalds has officially announced that version 3.7 of the Linux kernel has gone stable, and that means good news for developers who work with ARM-based CPUs: among its other changes, Linux 3.7 is the first Linux kernel to include generic support for multiple ARM CPU architectures, reducing the amount of effort required to get Linux-based operating systems running on phones, tablets, and ARM-licensed developer boards like the Raspberry Pi.

At present, every time a developer wants to port a Linux system to an ARM system-on-a-chip, they have to build a new kernel to support that processor’s particular architecture. Additionally, differences between ARM chips from different companies means that porting that same Linux-based OS to another ARM processor—for example, taking code running on a Samsung SoC and making it run on a Qualcomm SoC—requires another kernel. The work required to maintain these separate kernels for each ARM SoC is a major roadblock for the architecture compared to x86 chips traditionally used in desktops and laptops, and overcoming this issue will be a major step forward for Linux and its forks, including Android.

This work mirrors the effort that Microsoft also exerted for Windows RT, which likewise supports many different ARM architectures with the same kernel.