May 31, 2008 at 9:37 pm | Posted in Lifescape | Leave a comment
Tags: scientic advances
DNA Computer Puts Microbes to Work as Number Crunchers
Study shows genetic material in bacteria can be harnessed to solve complex math problems
By Nikhil Swaminathan
Researchers have put DNA computers inside living cells for the first time.
It’s not your normal, electronic silicon-based machine, but scientists have made a computer from a small, circular piece of DNA, then inserted it into a living bacterial cell and unleashed the microbe to solve a mathematical sorting problem.
“A computer is any system that can read some input and give some readable output,” says Karmella Haynes, a biologist at Davidson College in North Carolina and co-author of a new study appearing in the Journal of Biological Engineering. Haynes and her team looked to harness the power of DNA recombination to solve the so-called “burnt pancake problem”: a puzzle about how to stack different-size flapjacks that are burned on one side and perfectly cooked on the other using the fewest number of flips to arrange them so the largest are on the bottom and all are golden side up.
“This work is the first work I’ve encountered which uses living cells in order to solve a specific computer science problem,” says Tom Ran, a graduate student in the lab of computer scientist Ehud Shapiro at the Weizmann Institute in Rehovot, Israel. …more
May 31, 2008 at 8:54 pm | Posted in Mindscape, scientific advances | Leave a comment
A new computer algorithm can guess what you are looking at based on brain activity alone
By Christopher Intagliata
of science-fiction authors have imagined a future that includes
mind-reading technology. Although the ability to play back memories
like a movie remains a distant dream, a new study has taken a
provocative step in that direction by decoding neural signals for
Neuroscientist Kendrick Kay and his colleagues at the University of
California, Berkeley, were able to successfully determine which of a
large group of never-before-seen photographs a subject was viewing
based purely on functional MRI data. By analyzing fMRI scans of viewers
as they looked at thousands of images, Kay’s team created a computer
model that uses picture elements such as angles and brightness to
predict the neural activity elicited by a novel black-and-white
photograph. Then the researchers scanned subjects while showing them
new snapshots. Most of the time Kay’s model could single out which
image the subject was viewing by matching its prediction of brain
activity to the actual activity measured by the fMRI scanner, although
very similar pictures tended to baffle the program. …more
May 31, 2008 at 4:18 pm | Posted in Lifescape | Leave a comment
Nearly all other multicellular animals have strong safeguards against foreign DNA, but bdelloids’ seeming embrace of genetic detritus is in keeping with their general quirkiness: Shunning sex and entirely lacking males, the ubiquitous creatures are also extraordinarily resistant to radiation, as Meselson and Gladyshev demonstrated earlier this year in a paper published in the Proceedings of the National Academy of Sciences.
|Long viewed as straitlaced spinsters, sexless freshwater invertebrate animals known as bdelloid rotifers may actually be far more promiscuous than anyone had imagined: Scientists at Harvard University have found that the genomes of these common creatures are chock-full of DNA from plants, fungi, bacteria, and animals.
|bdelloids may acquire DNA by habitually disintegrating their genomes — something these unusual animals do regularly during periods of desiccation, which fractures their genetic material and ruptures cellular membranes. Miraculously, bdelloids can then spring back to life upon rehydration of their habitats, readily reconstituting their genomes and their membranes.
In the process of rebuilding their shattered DNA, though, they may adopt shreds of genetic material from other bdelloids in the same puddle, as well as from unrelated species.
|In principle, this gives them an opportunity to take advantage of the entire environmental metagenome