How well can human beings track scents?

` According to a Nature News article I was reading by Erika Check, people can learn to track scents if they would just give it a try!
` Sure, human beings don't have nearly as many genes that code for smell receptors than, say, dogs or rats. But is our sense of smell really as inferior as it seems? Noam Sobel at the University of California in Berkeley and the Weizmann Institute of Science in Israel, wondered just that.
` He and his team got out the chocolate essential oil and laid out detectable amounts in a grass field for a length of ten meters (32-feet).
` So, could people follow that trail? Thirty-two student volunteers were blindfolded and earplugged and set out to test this out. In ten minutes, each volunteer was given three chances to track this scent. Two-thirds of them actually did it! Practicing this task over three days, unsurprisingly, only turned up improvement.
` The team counted the number of inhalations the students were taking, and also found what happens when you block one nostril at a time. This, I found, was interesting: 'Stereo smell' has been discovered in rats before, and the fact that the students had trouble finding the direction of the scent with only one nostril suggests that people have this, too.
` Well, no kidding! Am I the only one to notice that people can tell the direction a scent is coming from?
` So, yes, we are capable of tracking scents. That is not so surprising. Of course, dogs can track scents that we can't even smell. Even so, it's good to know that you can trace an odor across long distances. (Especially, I suspect, if you crawl on the ground where the scent is at, like our four-legged friends do!)
` This, here, however, seems unfounded:

"We have a much better sense of smell than rats and dogs because of our greater brainpower," says Shepherd. "This shows that in a few training sets, humans can achieve something that other animals spend their life being trained to do."

` Here is the beauty of peer review and skepticism:

Dogs are still better at picking up the whiff of a particular person from a discarded item of clothing, or alerting officials to traces of drugs, explosives and other contraband, says neuroscientist Jess Porter of the University of California, Berkeley, and first author on the paper, which is published online by Nature Neuroscience2.

` Indeed, we can't smell everything that another species can. We also cannot discern between many scents. However, since a variety of animals use their sense of smell as their main sense (including hedgehogs, which can survive in the wild even if they are blind), it would be foolish not to try this out ourselves.

"Our work certainly proves that if you can smell something, you can improve your ability to track it. So if you walk by a bakery on your way to work and you can smell it, you can probably close your eyes and find your way to the bakery by your nose," says Porter. "That's more likely than sniffing out a bomb."

` Alas, why did I choose this one to point out? Because I wasn't in time to view these:

Dolphin feared extinct in polluted Yangtze
Overfishing and boat noise are killing aquatic mammals in Chinese river.

The mutation that takes away pain
Studies of rare disorder shed light on pain mechanism.

Saying goodbye to periods
Can women eliminate menstrual bleeding without problems?

Rare reptile fossil found in Antarctica
Researchers battle inclement weather to excavate juvenile plesiosaur remains.

` Waaaaah! What is wrong with these people? Taking them away before I can read them! The humanity of it all!
` However, I did not miss a most awesome article about how Turin's quantum physics hypothesis about the sense of smell does have some amount of credibility to it!