For dog owners, the meaning, intent and emotion of their pets' various vocalizations can often seem pretty obvious. A bark of hello sounds a lot different from the one you get when you inadvertently step on Fido's tail.

But do barks carry clear messages to other dogs? You would think so, but until recently, there was no clear evidence that dogs actually perceived differences between barks arising from different situations. For all scientists knew, it could all be mere yapping.

In a new study, however, researchers at Eotvos Lorand University in Budapest, Hungary, found a novel way to measure barking communication between dogs.

First, they recruited a cohort of pet dogs of various breeds from local training schools, then exposed them to recordings of Hungarian Mudi dogs barking in two different situations.

In one situation, a stranger had entered the property where one of the Mudi dogs lived; in the other, a dog was tethered to a tree and left alone. As control sounds, the test dogs were also exposed to recordings of an electric drill and a refrigerator.

As the dogs listened to each set of sounds, their heartbeats were monitored. Both of the types of dog barks initially caused the heart rates of the listening dogs to jump, though the rates tended to stabilize if the dog heard the same bark consistently over a period of time. Only the distress barking invariably prompted a new jump in heart rate. The drill and refrigerator sounds produced no reaction at all.

Researchers suggest this shows that dogs understand the different contexts producing the barks they hear, and that this understanding is a relatively new adaptation of domesticated dogs, since neither adult wolves nor feraldogs bark.

VERBATIM

You have a need in an evolutionary sense for both money and women.

- Camelia Kuhnen, a neuroeconomist at the University of Evanston, on research that showed when men look at erotic pictures or think they are taking a financial risk, the same part of the brain lights up

BRAIN SWEAT

How many four-letter words can you find in the word "twinkle?" (Bonus points if you find more than 20.)

BRAIN SWEAT ANSWER

Here are 20 four-letter words found in "twinkle": twin, kiln, wink, link, tine, newt, went, wine, kilt, wilt, welt, tile, kite, wile, lint, lent,like, kine, lien, line.

Prime numbers

82 - Distance, in feet, from which ThruVision's terahertz camera can peer through clothing to find concealed weapons

300,000 - Amount of chemical weapons, in tons, tossed over the sides of U.S. and other warships at sea between 1946 and 1972

86 - Number of kakapos (giant flightless parrots found in New Zealand) left in the wild

Sources: ThruVision; Medea Committee; New Scientist

ELECTRON INK

Godsbot

Godsbot.org

According to the home page, this is where "artificial intelligence talks to people about God." It's "Christian AI that is always on and alwaysready to listen and chat."

Users are asked to make a $10 donation for a year's worth of 24/7 access, but there's also a place to click for a free demonstration. Eureka triedit, asking four questions:

Eureka: Do you believe in Darwin's theory of evolution?

Godsbot: Knowledge is superior to belief.

Eureka: How old is Earth?

Godsbot: Six billion years.

Eureka: How old is the universe?

Godsbot: The same age as you.

Eureka: Are you real?

Godsbot: Yes, I am a real imaginal clone.

QUIRKS OF NATURE

The killer whale is not a whale at all, but the biggest member of the dolphin family.

ANECDOTAL EVIDENCE

Albert Einstein once observed that it would be hard to teach in a co-ed college because all of the male students would be primarily interested inall of the female students.

An admirer of Einstein's objected, suggesting that girls would be forgotten in the presence of the sheer brilliance of Herr Einstein, who even then was considered among the great scientific minds of all time. The men, said the admirer, would focus entirely on what the great physicist had to say.

Perhaps, Einstein replied, "but such men wouldn't be worth teaching."

WHAT IS IT ANSWER

Aseroe rubra, or anemone stinkhorn, a species of fungi found in Australia and recognizable by its star-shaped, slime-covered structure and distinctive odor of decay. The foul smell attracts flies, which spread its spores.

ANTHROPOLOGY 101

Chinese brides once suffered a three-day ceremony called nao-sin-fang, during which any person might demand to see the bride to insult her with impertinent and ribald remarks.