UNI TECH BLOG I

Washington, DC: Sharks have a keen sense of smell and a remarkable ability to follow their noses through the ocean, right to their next meal. Now, scientists have discovered how the sharks manage to keep themselves on course.

Researchers found that sharks can detect small delays, no more than half a second long, in the time that odors reach one nostril versus the other.

When the animals experience such a lag, they will turn toward whichever side picked up the scent first.

“The narrow sub-second time window in which this bilateral detection causes the turn response corresponds well with the swimming speed and odour patch dispersal physics of our shark species,” known as Mustelus canis or the smooth dogfish, said Jayne Gardiner of the University of South Florida.

All in all, it means that sharks pick up on a combination of directional cues, based on both odour and flow, to keep themselves oriented and ultimately find what they are looking for.

If a shark experiences no delay in scent detection or a delay that lasts too long-a full second or more-they are just as likely to make a left-hand turn as they are to make a right.

These results refute the popular notion that sharks and other animals follow scent trails based on differences in the concentration of odor molecules hitting one nostril versus the other.

It seems that theory doesn’t hold water when one considers the physics of the problem.

The study has been reported online on June 10th in Current Biology, a Cell Press publication.

ELECTRONIC STAMP

In a bid to thwart spammers, researchers are planning to add a “postage stamp” to emails. The plan of pay-per-email, they say, will help reduce unwanted spasm and the money thus generated will go to charity.

Spam is more abundant than ever, making up more than 90% of all email sent globally. Most is intercepted by anti-spam programs that filter mail by its origin or content. Yahoo! Research’s CentMail is resurrecting an old idea charge every email being sent so as to make spamming uneconomic, New Scientist reported.

What’s more. The cent paid for an accredited “stamp” to appear on each email goes to charity. CentMail’s inventors think it will be more successful than previous approaches to make email coast. They think the cost to users is offset by the good feeling of giving to charity.

The problem with any such “economic” approach is that it costs money or effort for legitimate, Yahoo! Researcher    sharad Goel explains. By passing the money onto a charity of the sender’s choice, and showing the donation in a “stamp” at the bottom of every email sent, CentMail aims to make senders feel an altruistic glow to balance that perceived cost.