Stories tagged smell

And when I've got a headache, I reach for aspirin and caffeine, sometimes with a little hit of acetaminophen besides. Today, when I popped open the aspirin packet, I got wondering about that faint vinegar-y smell that aspirin often has.

Magic stuff: even if it's kind of smelly.
Magic stuff: even if it's kind of smelly.Courtesy jypsygen

Turns out that's chemistry in action. And probably also lousy storage. (And, yes, I realize Yahoo! Answers is not a good source, but some additional poking around confirms that this is the correct explanation, and the best written one, too.)

Dude! No!: Aaargh! It's too late! Might as well get a job as a crime scene cleaner now.
Dude! No!: Aaargh! It's too late! Might as well get a job as a crime scene cleaner now.Courtesy Dimmerswitch
Check it out: The Food and Drug Administration is recommending that people avoid Zicam. Why? Because it may cause you to lose your precious sense of smell.

Zicam (Zicam nasal gel in particular) is a popular homeopathic cold remedy. (I say it's popular because the NY Times says so, and because I vaguely remember seeing a bottle of it lying around my living room this winter.) You stick it up your nose, and blast away. It's got zinc, galphimia glauca, histamine dihydrochloride, luffa opercolata, and sulfur in it. These ingredients are reported by some people to reduce the length or severity of the common cold (although the virus remains incurable).

Over the last several years, hundreds of people have reported that use of Zicam has destroyed their sense of smell. The manufacturers of Zicam paid out $12 million to some of these people in 2006, although their attitude in general has been, "Well, y'all have the cold. What did you expect to smell?"

The FDA, on the other hand, has pointed to the connection between zinc in other nasally administered drugs, and the loss of the sense of smell, or "anosmia." They're all, "Hey, everybody, stop using Zicam if you want to continue smelling things forever. And, Zicam people, cut it out. We need our smells."

And the Zicam people are all, "Whatever. If anybody wants their money back, just ask. Otherwise, enjoy some more Zicam!"

What does everybody think? Fans of Zicam out there? Is the possible risk associated with this homeopathic remedy insignificant compared to any problems associated with conventional cold symptom medications? Anybody lose their sense of smell from Zicam? Anybody lose their sense of smell from, like, anything?

Let's have it.


Secrets of scents: click on "oceanhug" for a bigger picture
Secrets of scents: click on "oceanhug" for a bigger pictureCourtesy oceanhug

Smelling a certain scent can trigger memory and emotion

Because the olfactory part of the brain is in an area sometimes called the "emotional brain", smell can call up memories and powerful responses almost instantaneously.
Smell can be very important like when smelling smoke warns us of a fire or smelling rotten food prevents poisoning. If humans are at all like animals, smell may even influence who we will marry.

For instance, when a male mouse meets a novel female mouse, he will spend a long time sniffing her body, and especially her hind end. This not only tells him if she's ready to mate, but also by sniffing different females the male can chose to mate with those that are less genetically related to him. The Naked Scientist.

How does smell work?

Our sense of smell, also known as olfaction, involves an interaction between air born molecules called odorants and sensory neurons within our nose. The interaction is viewed by many as working like a key and lock. If the odorant is the right shape, it will fit into an appropriately shaped receptor site causing the nerve to react (fire), and a signal will be sent to the brain. An alternative theory, the vibration theory proposed by Luca Turin, posits that odor receptors detect the frequencies of vibrations of odor molecules in the infrared range by electron tunneling.

Humans have limited olfactory skills

Our genetic code determines how many and what kind of smell receptors we have. Human smell is very limited compared to many animals (and insects). Bloodhounds can pick out the scent of one human from hundreds of others even when the scent trail is several days old. It is fun to see how much fun dogs have checking out all the smells around them (and rolling in the really good ones).

Perfume science can be worth big money

I highly recommend watching this video, "Science of Scent" in which Luka Turin explains how his company is making money by creating customized scents. Luka Turin, along with his wife, Tania Sanchez, also wrote a book titled "Perfumes: The Guide" which is on Amazon's "Best Books of 2008" list. The link will take you to reviews of why it is so popular or you can sample some quotes here or look inside the book here.


If anything, sir, you're making it worse: You can wring out the sweat, but not the stink.
If anything, sir, you're making it worse: You can wring out the sweat, but not the stink.Courtesy The Michael
Yeah. Sorry. I don’t make the rules—y’all just have your own weird odors, and there’s nothing you can do to change them. Frowny face.

But, today of all days, try to get past your own problems (though they are disgusting and abounding) and be grateful to the men and women who have fought for your country. Or think about Armistice Day, and the moment on the eleventh hour of the eleventh day of the eleventh month of the year 1918, when the bloodiest war the world had ever seen finally came to an end.

No? That’s not doing it for you? Still stuck on yourself? Fine. We’ll deal with that first.

Oh, by the way, the statement about your having a unique, personal stink is predicated on my assumption that you’re all mice. Not figure-of-speech mice, but actual little rodents. Who have computers and can read. (And, really, what illiterate mice are going to have computers? It just goes to show that you won’t be getting ahead without an education.) Even if you aren’t mice, however, I suppose there’s a decent chance that the personal odor think applies to you (you might not be conscious of it, but that doesn’t mean it’s not there).

There are all kinds of things that can affect your stank. You should know that by now. Bacteria, for one, love eating your excretions and covering you with effluvia of their own. It smells bad. And your excretions aren’t necessarily a walk in the rose garden in the first place. Depending on what you eat, you can end up smelling like the dumpster behind a German restaurant (I’m thinking onions, garlic, and red meat here) or the dumpster behind a South Asian restaurant (ah, sotolon). Really, you could smell like any number of dumpsters across the globe, depending on your tastes.

But it turns out that no matter what stank you might give yourself with all that coffee and garlic pizza, you’ve got a unique stank that’s all your own, and there’s nothing to be done to change it.

See, scientists have been watching little mousies, and they’ve found that although body odors brought about by diet can be confusing to mice in identifying other individuals by their odor, there remains a unique, identifiable, genetically-influenced smell in each mouse, despite the particulars of its diet.

That was a long and bad sentence. What I meant to say was this: no matter what you eat, it seems that you have an unchangeable, unique smell. It says so here. And in far fewer words here.

What’s the upshot of this? First of all, it’s like I said: you’re hopeless, Oldspice. However, the research also suggests that someday technology could be developed that would identify individuals by their unique odor “fingerprints.” A personal odor database could be developed. Think about that—you put your fist through a bakery window just once, and the fuzz has your stink on file forever. Or maybe you wouldn’t have to show your passport to get on a plane—a robot could just sniff you. Another robot, anyway.

A brave new future, huh?

Mmmm, that smells good: New research concludes that T-rex dinosaurs had an excellent sense of smell.
Mmmm, that smells good: New research concludes that T-rex dinosaurs had an excellent sense of smell.Courtesy ArthurWeasley
One of the first things I learned in my time here at the museum is that everything we know about dinosaurs we learn from the fossil record. Since then, we've posted numerous stories here about non-fossilized factors to dinosaurs. Here's another story that challenges the fossil record assertion. Researchers have discovered that T-Rex dinosaurs very likely had an extraordinary sense of smell. Click hear to learn how they've figured that out.


Old-school smeller: This is how we process smells today. With new advancements in receptor protein cell development, we might someday have artificial noses to help with that work.
Old-school smeller: This is how we process smells today. With new advancements in receptor protein cell development, we might someday have artificial noses to help with that work.Courtesy LHOON
That old beak on the front of our face might be in for some serious competition in the future.

Our nose has held exclusive rights on sniffing out the multitude of odors that swirl around us. But with this latest scientific breakthrough, it might be given a run for its money.

Researchers at MIT have figured out how to mass produce the receptor proteins that make up the cells that work in as the receptors in our nose that begin the process of the sense of smell. With further development, these receptor cells could be used in the development of artificial noses. Taking that futuristic thinking a few steps further down the line, an artificial nose could have applications in area like law enforcement, where they could be used to sniff out illegal drugs or explosives. In home security, an artificial nose could be helpful in identifying natural gas leaks or the start of an unintended fire.

Here are the full details of the research. But it’s got me thinking, what other good purposes might there be for artificial noses? Let’s get the ball rolling right here on the Buzz. Share your thoughts with other readers.


Makes me wonder...: Where were you on the night of the incident?
Makes me wonder...: Where were you on the night of the incident?Courtesy kalimistuk
A French dog, nicknamed “Scooby,” may be the first animal in the history of animals to be used as a witness in a murder trial.

Scooby, whose real name (I’m guessing) is being withheld for his own safety, is believed to have been present when his 59-year old owner was hung from the ceiling of her Paris apartment.

The death was initially supposed to be a suicide, but the dead woman’s family demanded a murder investigation. During the preliminary trial, the dog was lead to the witness box to see how it reacted to a suspect. Scooby is reported to have started “barking furiously” as he neared the suspect.

The judge has yet to decide whether there’s enough evidence to launch a full murder inquiry, but was very impressed with Scooby.

In addition to the outburst at the witness, however, several crotches and one butt have been added to the list of suspects.

Soooo… How can this be a science story? Well, let us consider the olfactory prowess of your average dog, and how that could possibly be considered as evidence in a case that would put a person in jail for, no doubt, a long, long time.

I don’t know if you live in an area where skulls—preferably mammal skulls—are readily available. If you do have a local skull store or skull pit, however, do yourself a favor and grab a skull or two. If you check out the nose hole (don’t use that term on any skull-themed tests, by the way), you’ll see a bunch of thin, bony, scroll-shaped plates. Air passing through the nose hole (again…) is spread out over the surface of these plates. The chemicals that give inhaled air its odor are dissolved into the mucus produced by the spongy tissue covering the plates. The chemicals (or odors) in the mucus are then detected by little antlered nerve cells (keep that one off the test too). These nerve cells run pretty much directly to the brain, where the detected chemicals are analyzed. The brain can then decide if you’ve just smelled triple berry pie, or, say, a French murderer.

Now, while I know of several individuals I could probably identify by smell, I’m pretty certain that I couldn’t pull your average French murderer out of a lineup by odor alone. But, then, I’m no dog.

The area of tissue covered with smell receptors in a human’s nose slightly less than a couple square inches—about the size of a big postage stamp. A dog, on the other hand, has enough smell receptors to cover an area of tissue almost as big as a standard sheet of printer paper. And while all dogs are significantly better smellers than humans (that is to say, better at receiving smells, not giving off pleasant ones), certain breeds of dog far outstrip the rest. A human, for instance, has about five million smell receptors. A wiener dog has about one hundred and twenty five million smell receptors, and a German shepherd has two hundred and twenty five million. Bloodhounds have about 300 million smell receptors. What’s more, the percentage of a dog’s brain devoted to analyzing smells is 40 times larger than the same area in a human’s brain. All things considered, it is thought that dogs are perhaps ten thousand times more sensitive smellers than humans. (Or, if you go by Wikipedia, a dog’s sense of smell is as much as one hundred million times more sensitive than a person’s. But I’d keep that off the test too.) Add all this to the notion that individuals may have unique individual odors, and it makes sense that a dog might be able to identify a person who had murdered their companion/owner.

Then again, I’m not sure I’d want to leave something like that up to a dog.


But, in Smellovision,: it would be beautiful
But, in Smellovision,: it would be beautifulCourtesy Kaptain Kobold
It’s amazing how the scientific process works out. I, for instance, have spent many years attempting to test the statement regarding killing two birds with one stone. Progress made towards the main research question (How good, in fact, is killing two birds with one stone? Pretty good?), has been, well, convoluted: more than anything else, I have uncovered obstacles. It turns out that many birds can fly, and that I am very poor at throwing, both factors significantly complicating the stoning process. This sort of things is only to be expected in science, but it means that one problem (at least) must be dealt with before another can be dealt with fully. In my own research, I’m thinking that it might be best to fasten both birds, somehow, to a plank, where a single stone can more easily be applied to each. Then, perhaps, I can see how things are different after they are dead.

Anyhow, the point is, research can take you all kinds of interesting places, and it seems that the work of scientists at Rockefeller University has mirrored my own in this respect.

Like so many other scientists, the Rockefeller researchers are studying flies (approximately sixty-five percent of all science performed today is fly-related). They are interested in how flies navigate by use of smell. Flies, or at least the variety observed at Rockefeller, have two olfactory organs, two noses, essentially, and the scientists are able to genetically modify the bugs so that one, two, or neither of the noses work. When they then observed the way fly larvae move towards a certain controlled smell, they found that one-nosed flies could still sense the source of an odor, but not nearly so well as those flies with two noses. The flies were smelling in stereo.

Stereo smell would be great, I think. Our stereo vision gives us depth perception, and our two ears allow us to pinpoint sounds; with stereo smell there would never again be a question as to who dealt it. Nor would there be if the other product of Rockefeller’s research were marketed: a little something no one is calling Smellovision.

In order to fully understand how the flies were reacting to odors, the scientists needed a way to observe the exact dynamics of the smell, to see how and where it was concentrated at all times. So that’s just what they did – they created a way to see the smells. They developed “a novel spectroscopic technique that exploited infrared light to create environments where they could see, control and precisely quantify the distribution of these smells.” Smellovision. That would also be pretty rad – if you were really stinky, you could look like a cartoon character, with stink lines and green clouds and everything, qualities that I believe we all aspire to.

It’s an inspiring story all around, I think. I mean, there’s no reason for me to get frustrated with my research. Sure, some of the work feels like sidetracking, but maybe it will lead to my discovering a great, efficient new way of killing birds with stones. You just never know!


Scent of death?: A Providence, R.I., cat, (not pictured above) that lives at a nursing home has an uncanny ability to find and curl up by residents who are about to die. (Photo by grafwilliam)
Scent of death?: A Providence, R.I., cat, (not pictured above) that lives at a nursing home has an uncanny ability to find and curl up by residents who are about to die. (Photo by grafwilliam)
This has been the main topic of side conversations of floor staff members at the museum today.

Have you heard about this cat in a Providence, R.I., nursing home that has correctly identified the last 25 patients who were to die there?

Oscar, the cat, makes the rounds of the nursing home each morning, just like the medical staff. Some mornings, Oscar will then slip into a room, curl up next to an ailing patient. Within several hours, that patient dies. The cat is so accurate, nursing home staff members will call the family of a resident being visited by Oscar so that they can be present when their loved one passes away.

“He seems to understand when patients are about to die,” says Dr. David Dosa. “Many family members take some solace from it. They appreciate the companionship that the cat provides for their dying loved one.”

Before you get too creeped out by this, doctors at the nursing home say that most of the people Oscar visits are so sick, they’re not aware that he is there. And families, for the most part, seem to be pleased that their loved one got some special attention from Oscar before the death.

Is there science behind this phenomenon? After all, there are dogs that can sniff out oncoming epileptic seizures and there are rats that can sniff out buried land mines.

One theory is that Oscar picks up scents or reads something into the behavior of the nurses who raised him in being able to determine if a patient is going to die. One researcher points out that the only way to know for sure is to do a study of Oscar’s behavior when someone is dying compared to what he does when people aren’t dying.

What do you think is going on here? Share your thoughts with other Science Buzz readers.

Being one never to have a lot of trust in cats, especially after seeing the movie "Cats and Dogs, I’d like that investigation to go a little deeper. Cats can be a lot more devious than appears on the surface.

Bee driven sensors: Courtesy Susana Soares.
Bee driven sensors: Courtesy Susana Soares.
An artist at the Royal College of Art in the United Kingdom has designed some beautiful glass sculptures that could help use bee's amazing powers of smell to help detect disease. Susana Soares was inspired by recent news on research to use bees to sniff out chemical weapons and bombs.

Also check out:

University of Montana's Bee Alert program.
More on bees from Science Buzzzzzz