Stories tagged smell

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 LHOONThat 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.

Tags : nose, smell, odor, artificial nose, receptor proteins

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Makes me wonder...: Where were you on the night of the incident?
Courtesy kalimistukA 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.

Tags : dogs, smell, murder

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But, in Smellovision,: it would be beautiful
Courtesy Kaptain KoboldIt’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!

Tags : senses, smell, flies, bird killing

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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.

Tags : smell, animals, health, cats, detection, death, nursing home

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Yes, we do smell in stereo. So are you left-nostriled or right-nostriled?

According to the findings of a new study, humans (along with a lot of other mammals) compare the scents that come into their nose through each nostril to make more refined decisions as to what they’re smelling. And the research conducted on the study sounds like it would have been a lot of fun to participate in.

College students were blindfolded and asked to crawl through grassy fields, using their noses to find a chocolate-scented trail.

Their task was to follow a 30-foot-long path of twine that had been scented with chocolate. The students were blindfolded, gloved and geared up with knee and elbow pads so that they could not feel the twine as they sniffed their way for the chocolate course. They also had ear plugs to shut of that sense as well.

Before hitting the grass, they were shown a quick video of proper sniffing technique of putting their nose to the ground. Evidently most humans are adverse to poking their nose into the ground.

An amazing two-thirds of the participants were able to smell their way through the dog-legged course. But with one of their nostrils plugged, nobody was able to find their way to the end of the chocolate twine.

Armed with these findings, researchers are now figuring that our brain compares the information it gets from each nostril to decipher where and from what the smell is coming. That’s very similar to what our ears and eyes do in processing information about sound and sight.

But for a long time, it was considered that the nose worked as a single sense researcher since the nostrils are located so close together on a nose. Could there really be that much difference in the smells going in one nostril compared to the other?
The findings of the nostril research are published on the website of the journal Nature Neuroscience and will be expanded on in the January issue of that journal.

The chocolate in the grass experiment was just one of five tests done on the nostril theory. Another experiment tracked the paths that tiny bits of theatrical fog took as they were breathed in by study participants.

Armed with this new data, researchers will be fine-tuning their next experiments to get even more specific on how our noses actually work. They’ll be taking a look at questions like does our brain actually detect two separate aromas from our nostrils. Or does having two nostrils taking in a smell give us a stronger concentration of the smell to be able to process more detailed information about the smell.

Smells like some more fun experiments on the horizon. What kind of experiment would you design to figure out more about how our noses work?

Tags : smell, nose, nostril

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Tongue ESP: The tongue can be used to sense input from machines via a grid of electrodes placed on the tongue which is stimulated with electricity.

Using Tongue ESP?: She probably isn't but could be in the future.
Courtesy Creap

What extra sensory perceptions would would you like? Seeing behind your back? Smelling odorless gasses like carbon monoxide? How about seeing in the dark? Sensors already exist that can do these things. All that is needed is a way to input what they sense into our brains. The most common way to input information from external sensors is visually. We can use our eyes to see distant airplanes or weather clouds on a radar scope. We can read how much carbon monoxide is in the air we breath by looking at a meter.

Suppose we need to sense things without using our eyes. Most often when we cannot see, we use our fingers to get information. Blind people use a cane to feel thier way around. Sometimes they tap their cane and listen for echoes to sense a barrier.

Another way to sense data about our environment is with our tongue. Suppose a ten by ten grid of electrodes were placed on the tongue and small voltages were used to create various patterns of sensation on the tongue. Just like bumps on paper can create thousands of words for people trained to read braille, the hundred electrodes on the tongue can allow trained people to sense data from sonar, radar, toxin detectors, or any other data measurable by various sensors.

At the institute for Machine and Human Cognition (IFHMC) Anil Raj is principle investigator in research titled: Adaptive Human/Machine Multi-sensory Prostheses. They are working on TSAS: Tactile Situation Awareness System. The research is exploring how electrodes on the tongue or in a body suit can allow users to receive input from external devices. Such input is desirable when your hands and eyes are already too busy or when they cannot be used.

Tags : remote sensing, sensors, senses, smell, tongue, computers

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