MIT team refines optical 'lab on a chip'

Figure illustrates "lab on a chip" technique developed by MIT researchers to allow immobilization and imaging of a live C. elegans worm: (a-i) worm moves freely in chip's microfluidic channel; (a-ii) partial immobilization of worm; (a-iii) full immobilization; (b) low magnification image of worm immobilized in the device; (c) close-up of immobilized worm showing animal's neurons

Live-animal nerve regeneration study gets a boost.
An MIT team has improved upon its landmark technology reported last year in which the researchers used a fingernail-sized lab on a chip to image, perform surgery on and sort tiny worms to study nerve regeneration.

The team has found a unique way to immobilize the animals while they are still awake for several minutes with unprecedented stability, which then allowed the researchers to conduct fast, detailed three-dimensional imaging and to perform high-resolution laser nanosurgery on the animals.

The advance, which builds on a technology first reported last year, could ultimately help researchers better understand the genetic underpinnings of regeneration and degeneration in the nervous system--not just in the worm but in more complex organisms including humans. That, in turn, could help in treatments of neural injuries and diseases such as Parkinson's and Alzheimer's.

Led by Mehmet Fatih Yanik, MIT assistant professor of electrical engineering and computer science, the team reported its latest work in the April 2 advanced online issue of the journal Lab on a Chip. The work involves the C. elegans worm, one of the tiniest multi-cellular organisms known. Smaller than a human hair, the worm is considered a key model for investigating a variety of biological phenomena such as aging, fat metabolism and neurological diseases.

Geneticists have been studying C. elegans since the 1960s, but the manual processes they used to do so were painstaking and time-consuming. That changed in a big way last year when Yanik and colleagues reported in the Proceedings of the National Academy of Science that they had developed a microfluidic chip to automate and accelerate research on the tiny worms. Essentially, the tiny worms are flowed inside the chip, immobilized by suction and imaged with a high-resolution microscope.

The research published this month goes one step further. Yanik and two collaborators, lead authors Fei Zeng, a postdoctoral fellow in the Research Laboratory of Electronics, and Christopher B. Rohde, a graduate student in electrical engineering and computer science, said they were able to render the animals motionless in the chip with an unprecedented stability for several minutes instead of seconds. This then allowed them not only to conduct three-dimensional imaging of the worms at the sub-cellular resolution but also to reliably operate on the animals with a high-precision surgery laser to study neural degeneration and regeneration on the chip. Yanik's team had previously demonstrated that neural regeneration can be studied in C. elegans using femtosecond laser micro-surgery.

"This new technology is allowing us to study the entire genome of the animal in very short periods of time," Yanik said. "We are currently combining it with genetic and drug screens to study neural regeneration on these animals."

Yanik received the NIH Director's Innovator Award last year for developing the lab on a chip technology to screen whole animals and study neural regeneration.

The research was funded by NIH Director's New Innovator Award (1-DP2-OD002989-01) and Packard Award in Engineering and Science, and Merck & Co. Inc.

Apple Inc. has changed its software update tool for Windows users

Apple makes minor concession on pushing Safari to Windows users
Separates updates and new offers, but Mozilla wants more.
Apple Inc. has changed its software update tool for Windows users so that it separates updates for already-installed programs from offers to install new software.

Last month, John Lilly, Mozilla Corp.'s CEO, took Apple to task for using the update tool, familiar to Windows users as the mechanism for updating iTunes, to push the Safari browser to people who had not previously installed the program. Lilly said the practice "undermines the Internet" and "borders on malware distribution practices."

Lilly's comments, which appeared in a blog post, raised a furor, with Apple defenders calling his criticisms, among other things, a "mountain out of a molehill" and a "load of crap."

Apple has updated the Windows utility, dubbed "Software Update," to version 2.1. That version features a split-pane displays that lists "Updates" atop and "New Software" below. On Windows XP and Vista machines sans Safari, for instance, the Apple browser appears in the New Software section, with its selection box pre-checked.

Mozilla noticed the change.

Asa Dotzler, Mozilla's director of community development, said the move was "an important, though not sufficient, improvement" and called on Apple to go a step further. "Now Apple needs [to] stop checking the box for 'New Software' items by default," he said in a post to his blog.

In his March reproach of Apple, Lilly had also brought up the checked-by-default box; today he echoed Dotzler. "Good change! A bit more to do..." he wrote on his blog.

It's unclear when Apple first started offering Software Update 2.1; there was no mention of it on Apple's Web site, for example. On Windows Vista, however, the installed tool carries a date stamp of April 11.

"In this latest release we have made it easier for customers to identify between software updates and new applications," said Apple spokesman Anuj Nayar. He declined to comment on whether Apple made the change in response to last month's criticisms, or if it would consider Mozilla's request to deselect the Safari install box.

Apple updated, Safari to 3.1.1 yesterday fixing four flaws in the Windows version and two in the Mac edition. One of the two bugs on the Mac side had been used in a hacker contest last month by a researcher who took home a $10,000 check and the MacBook Air notebook he hacked.

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Apple and Mozilla are busy this week deploying security patches for their browsers, Safari and Firefox. The security holes could have left users open to malware installation and cross-site scripting attacks, according to advisories posted by Apple and Mozilla.
On Wednesday, Mozilla issued a security advisory on the company Website alerting users that a security bug involving its Javascript Garbage Collector function by which specially-crafted Javascript code could cause memory corruption.

The company also warned that because Thunderbird, an email application, shares the browser engine with Firefox, that program could be vulnerable if JavaScript were to be enabled in mail. Mozilla warned users against running JavaScript in mail.

"This is being fixed primarily to address stability concerns," the advisory read. "We have no demonstration that this particular crash is exploitable but are issuing this advisory because some crashes of this type have been shown to be exploitable in the past."

On the Apple side, the patch fixes two flaws in the Mac version of Safari and four flaws in the Windows version. For Windows systems running Safari, the patches fix vulnerabilities that hackers could exploit by remotely installing malware on the user's system.

Another patch involved a flaw in Safari's open source WebKit framework (which also powers some elements of Apple Mail and Dashboard applications) that could allow attackers the opportunity to write a cross-site scripting attack. This security hole also affects Safari's Mac users, where a maliciously crafted Web page may lead to an unexpected application termination or arbitrary code execution, according to Apple's advisory.

The WebKit patch, amongst other security issues, was a vulnerability discovered by security researcher Charlie Miller, who hacked a MacBook Air by exploiting an unknown vulnerability in Safari as part of the Hack-a-Mac contest at the CanSecWest security conference in Vancouver in March.