SciTech Now Episode 419

In this episode of SciTech Now, we see how climate change impacts the water; a look at one scientist who studies dogs and the complexities of their noses; exploring the Mayan pyramids; and the decline in the boreal toad population.



Coming up, the human impact on our water.

And, all of a sudden, the nutrient mix was right, and -- bingo -- the bloom came about.

A scientist sniffs out the world of dogs.

They are living in an olfactory world, not in a visual world, like we are.

Detecting ancient history.

We use subatomic particles, called muons, and measure their direction, see where they came from, and, basically, reconstruct an image.

Fighting toad fungus.

Chytrid is a fungus that lives on the skin of an amphibian, and it will harden the skin, making it harder for the amphibian eventually to move, but primarily for any water or any gas exchange.

It's all ahead.

Hello. I'm Hari Sreenivasan.

Welcome to 'SciTech Now,' our weekly program bringing you the latest breakthroughs in science, technology, and innovation.

Let's get started.

Most people assume the water they're drinking is safe and protected by government regulations.

However, one community in Central New York is learning that even the most pristine of lakes can fall prey to the effects of climate change and the human footprint.

This segment is part of an ongoing public-media reporting initiative called 'Peril & Promise,' telling the human stories and solutions of climate change.


Well, this is the first time that any of us that have been around the lake for a period of time have ever seen an algae bloom of this nature.

On September 13th, we got a call from a gentleman across the lake.

And he said that he thought he had an algae bloom, and could we check it?

And we located some strips of algae on the surface of the lake and we scooped up a little bit of that and we sent it into the lab at ESF for analysis.

And it wasn't much.

It was really quite modest.

And so we didn't worry too much about it on that day.

And that was a Wednesday.

On Friday, I got up in the morning, walked out onto the deck, and looked out at the lake.

And -- holy cow -- there was a big band of green algae all across the surface of the lake in front of the house.

And about two hours later, we got a call from the lab.

We will sometimes get 60 to 70 samples a day.

And so to actually process them through quick enough, we have to have instrumental technique that can do it on the order of seconds.

The ones we see that are interesting then go back under a very traditional microscope.

We've done 3,000 samples this summer.

Cyanobacteria, blue-green algae, are a very, very old lineage.

They first came around about 3 billion years ago.

Most blue-green algae, or most cyanobacteria, are not toxic.

However, the few that do are actually quite common.

So we see them in a lot of the different water bodies around here.

We saw the data where it had been really accumulated on the shoreline of the village.

And that was what we would say was an extreme toxicity.

Well, I can say we live on the lake and pull our water from the lake.

We get online, and, all of a sudden, the health department's telling us, 'It's dead-dog levels.

Don't let your dog go in.'

So that was terrifying.

Frankly, we'd been pretty smug over the years, because we've always prided ourselves living on one of the cleanest lakes in the world.

It's a double-'A'-rated lake.

The city of Syracuse and surrounding areas get their potable drinking water from this lake.

And we were told not to brush our teeth, not to cook our pasta with it, not to shower with it, even, because the microcystins vaporize in the steam in the shower, so take a quick shower.

So we were left shocked, basically.

When we talk about climate change, the models predict that we will get more rain in the spring, which should wash more nutrients into our lakes, followed by dry, relatively low-wind, warm, and sunny periods in the later parts of the summer.

Those are exactly the conditions that should lead to more blue-green-algae blooms.

The factor that seemed to kick this one off was the increase in nutrients, and that was caused, we think, by these torrential, torrential, heavy-rain events.

Our little ankle-deep creek turned into a thigh-deep river.

And we had literally tons of silt come into our beach and go south, and it changed the whole ecosystem of our little piece of the world.

And, all of a sudden, the nutrient mix was right, it was correct, and all the other stuff was there, and -- bingo -- the bloom came out.

And those heavy-rain events are a factor that's due to climate change.

Why do these blooms go away?

And they go away because the weather gets cold in the fall.

What we're seeing with climate change is -- our water is starting to stratify earlier in the spring and it's turning over later in the fall.

So, from the point of a blue-green algae, I have just increased the time I have to grow.

It was alarming to me to know that a citizen's organization found this, that the municipalities and the counties weren't checking for it.

Maybe we can be more thorough than what's required by the health department.

It's definitely not hopeless.

It will require some time to make the shifts that we need to make.

We need to stop thinking of the lake as an economic commodity, primarily, and we need to start thinking of it as an ecosystem.

What can we do to improve the health of our lake?


Dogs may be man's best friends, but how much do we actually know about our beloved pets?

Alexandra Horowitz, professor of cognitive science at Barnard College and author of 'Being a Dog: Following the Dog Into a World of Smell,' examines our four-legged friends by studying the complexities of their noses.

She joins us now.

How much more powerful is a dog's nose than our own noses?

I mean, we know that they can smell better, but give us the actual fact.

Right. It's tricky to make a numerical estimation.

We know that it's many, exponentially, times better, with many odorants.

So, we make estimates based on things like the number of olfactory receptor cells they have in their nose, the number of cells that are there in their nose to grab odors.

All dogs have hundreds of millions more receptor cells than humans do.

So that probably equals an ability to detect a minute amount of what we are.

And we see that in their behavior.

Sure. And is there some structural difference in a dog's nose, compared to ours?

Well, the whole nose is kind of designed, on the dog, to race odors through the nose and to the brain.

So the long nose is full of bones that hurry up air, warm and humidify the air.

In the back of their nose, they have a space where the odors can kind of linger.

It's called the olfactory recess.

We don't have anything like that.

They have all those hundreds of millions of olfactory cells, and then there's more of their brain committed to determining what the odor is.

So you looked at this almost at a study level.

What did you look at?

I've looked at a lot of levels of behavior because we can't ask the dog, you know, what do they perceive.

My interest is in looking at their behavior and trying to tell what they could perceive.

Now, there's research looking at how small an amount of TNT or other explosive is there.

My interest is more on the order of, 'Do they recognize themselves through their smells?

Can they determine quantity of a food item by smell alone?'

Things like that.

So can they recognize each other through smells?

It looks like they are recognizing not only each other but that they know their own smell and they know when something has changed about their smell.

This is sort of analogous to looking in the mirror and noticing that something's out of sort about your appearance or that there's spinach between your teeth or something.

Can they look in a mirror and see if there's something out of sorts?

They see in mirrors.

They can use a mirror as tools, but there's no evidence that they're using them to kind of guide their own grooming behavior the way we do, but then dogs are not groomers, so we wouldn't expect them to.

So instead I look at, you know, what's their smell.

Do they notice when their smell is different?

Because they're living in an olfactory world, not in a visual world like we are.

So does their smell give them a sense of self similar to how we look in a mirror and say, 'Okay, that is the external vision of myself'?


That's my sense, right?

And owners might behaviorally note this just taking their dog for a walk.

If their dog is peeing someplace, which is leaving information about themselves, they later don't go and investigate that smell, usually.

They're not going to see who that is.

They know who it is.

It's themselves.

They go and investigate other scents of other dogs who have been by.

When you looked at this, were you surprised by the results?

I was delighted by the results.

I was delighted to see that they might have an analogous sense of self in olfaction as in vision.

We've seen examples of dogs, of course, at airports trying to sniff out dangerous substances.

We've also seen dogs that have an ability to, I guess, figure out if prostate cancer exists just by looking at urine -- or cancers.

I mean, it's a really wide range of things.

How is it possible for them to be able to sort all of these categories?

Is it just about what's in their brain and that they can slice and dice?

It's like asking how can we see everything that we see in front of us, right?

At some level, we have experience.

We come with a visual system.

We have experience learning about what different objects are and naming them, so kind of organizing the visual percepts.

They have a rich olfactory percept, and when we tell a dog who we want to train to be an explosives-detection dog, 'When you smell this substance, I want you to alert for me,' they're already smelling it.

They don't have to learn to smell it.

It's part of their olfactory percept.

They just then learn that that's something that the humans want to know about, and they tell us.

When you were writing this book, what was the most surprising thing that a dog could smell that you figured out?

What I loved were the scat-detection dogs.

So there are actually wildlife researchers now who are trying to take canvases of populations of animals who are hard to find, you know, or over hundreds of thousands of acres.

And they found that they could use dogs to just detect the presence of scat, which gives them their DNA.

And, in fact, there's one dog, Tucker, in Puget Sound, who can detect orcas in the water a nautical mile away from the smell of their scat, essentially, from the boat, and then direct the researchers to where the orca is.

[ Laughing ] That's amazing.

It is kind of amazing.

It's mind-boggling, and I think it's ordinary stuff for dogs.

You know, one of the things you also mention in the book is about how we can actually train our sense of smell a lot better, that we're -- even though we don't have as many receptors as a dog does, we're not using them anywhere close to our capacity.

You know, we have a perfectly good sense of smell, and we know that because we taste food.

Most of our sense of taste is entirely because we smell.

In other words, we're smelling through the back of our nose instead of through the nostrils.

So we have all those receptors.

If you have a cold, you might not taste food, right?

And that's 'cause the receptors are blocked.

And I thought, 'Well, let's try to imaginatively leap into what it might be like to be a dog by starting to sniff more things myself.'

And that's the first thing we have to do, which we don't do.

I mean, we just have an aversion to putting our nose up to a substance and smelling it.

We find that funny or silly or foul.

And once you start doing that, you realize, 'Oh, actually I can detect it.'

Everything has an odor.

Everything has an odor.

And so there is this level of richness of the environment that you get a little peak into once you start sniffing.

Sense of smell is such kind of a powerful trigger.

Like, when you say, 'Garbage in New York on a hot summer day,' I just -- there's a vision that I have in my head, right?

Or, for me, it's rain falling on sort of fresh tarmac or a book, frankly.

At this point, [Chuckles] that's becoming something of a relic in the past, right?

But opening an old book, there's a certain smell that you get.

But it's really interesting how connected it is to sense memory and all these other senses.

It's a great trigger.


I mean, people like to say that smell is the quickest route to the brain because there really is just one neuron from the back of the nose, where the olfactory receptor cells are, and the olfactory lobe inside the brain.

And so, at some level, yeah, there does seem to be a more emotive, maybe an often unconscious connection that's made with something visceral, and we have all these great smell memories, right?

I ask people for their smell memories, and suddenly they're back in their grandmother's house when they were five and they're in the attic and the feeling of being that age at that time, with those people.

I'm surprised that, given that we have this often positive -- or at least very emotional connection with smell -- that we aren't intentionally smelling more, that we neglect to smell.

Alexandra Horowitz from the Department of Psychology at Barnard College.

Thanks so much.

Thanks very much.

Muon detectors are elementary particles used by researchers to look inside ancient pyramids.

Scientists from the University of Texas at Austin are using these detectors to explore the Mayan pyramids in Belize.

Roy Schwitters, professor of science at UT Austin, joins us via Google Hangout.

So, professor, how does a muon detector help me figure out what's inside a pyramid?

Make that connection for me.

What you want to find out is what's inside, as you say.

That's the question.

So you need to have something that gets inside and that you can track and then reconstruct an image of the material inside this huge space.

So we use subatomic particles called muons.

They're like heavy electrons.

They are found in cosmic rays and in particle-accelerator laboratories, and are used, actually, in these days, in many different technologies.

But they have the beautiful feature that penetrate deeply through dirt and mud and rock and all those things and yet can continue on a path through a huge object.

And we can detect them, and then they essentially tell us where they came from.

We can measure their direction, see where they came from, and basically reconstruct an image all along the path that they've taken through this material.

So these things are flying through the air all the time.

We just can't see them with our eyes, but we can -- How do we see that they actually are -- or what do they strike?

They actually go through the air and other materials around us, and they ionize it.

And so what that means is they leave a little track of ionized atoms, much like a jet airplane leaves a contrail in the high upper atmosphere.

So it's a very good analogy.

You can see the path of the airplane even if you can't see the airplane.

And so we do that by detecting the ionization, and that's done nowadays with a rather simple apparatus -- pieces of plastic, really, with a dye in them that emit light when the ionizing muons go by.

And so we can put a picket fence of plastic strips, and we watch as they go from one to the next, and we can reconstruct the path.

But I think the best analogy is a high-flying airplane, where you can't actually see the plane.

Okay, so, as they go through, do they change in direction or velocity when they bump into a harder object than when they are just going through something of the same consistency?

What they do is they lose energy to the ionization.

So as they go through a dense object, they lose more than they would've just going through air.

And the practical effect of that is some of them, by the time they get to our detector, don't make it.

They've lost all their energy.

And so they just -- they're AWOL.

They don't show up in our detector.

So the way we do this is we put the detector up on top of a building, say here on campus.

We measure what the open sky gives us in muons, and then we carry it down to a pyramid and look at the difference.

And, essentially, that tells us the amount of material that they've gone through.

So, if there's, say, a room or a cavernous area or something, what are you likely to see as the indicator of that?

It's almost like you're seeing the kind of shadow of where these muons hit and where they didn't.

Exactly right.

We see those shadows, we look at them in many different directions through the pyramid, and we can reconstruct a three-dimensional image of where the mass, where the material is in that object that -- You know, the eye only sees -- In Belize, it's so interesting.

The eye only sees a jungle-covered hill.

You wouldn't even know there was a pyramid in there.

And yet we can then see the dense rock.

We can see by inference... We hope to find caverns and chambers and all kinds of stuff, but that's how it works.

You've worked on Belize so far.

Is this technology that can be used in, say, the pyramids of Egypt or other places that aren't pyramids?

Very much so.

In fact, the whole idea here came from a... My field is particle physics.

And some of us were sitting around talking about how we'd do quite a different problem -- how would you find out if someone was drilling into your vault in the basement of your bank?

I mean, that's a silly challenge -- not so silly.

There was a news article that day.

And we recognized that this technology, which was invented by Alvarez 50 years ago -- one of the heroes of our field -- with modern implementation is quite a practical way to set up, essentially, cameras that could see if someone were tunneling into your bank vault.

My interest in the beginning was to develop the technology with the much better tools available today than were available 50 years ago.


And in doing so, we proved the efficacy of this and realized we have colleagues here at the university with pyramids.

You know, not everybody has a pyramid in their backyard.

These people are really experts in the extremely fascinating problem of the Mayan culture.

And so here was a chance to contribute to their science with our technology.

And it was just a great opportunity.

So, what did you find in Belize?

[ Chuckles ] Well, we're finding that it's difficult to do high-energy experiments in the jungle.

So we're really testing our technology to the limit.

We find that we can X-ray Maya pyramids.

That's all established.

But these experiments take a long time.

They take weeks to months.

So we want to take a good, long exposure this spring, and then we open the box and see what's inside.

All right.

Roy Schwitters of UT Austin.

Thanks so much for joining us.

You're very welcome.

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Found at high elevations in a variety of aquatic habitats in the Rocky Mountains, the boreal-toad population has decreased dramatically over the past two decades.

This decline is believed to be caused by climate change and the spread of a fungus that thickens the toad's skin.

In this segment, we join volunteer citizen-scientists, Utah's Hogle Zoo, and Utah's Division of Wildlife Resources as they gather data at Bryants Fork, Utah, on the health of the boreal-toad population.

Today we're out at Bryants Fork, and we have some volunteers and some students of the Master Naturalist course.

And we are just out surveying for toads, and it's kind of on-the-job training, and the data is all going back to the wildlife biologists.

So we're just getting more people out there, and you get to enjoy nature, and it's all for a great, bigger cause.

♪♪ So, when we find a toad, the first thing we do is scan it with a PIT-tag reader for a little PIT tag.

If it's been found before, we will have tagged it.

And a PIT tag is essentially the same as when you microchip your pet dog and it has its name and address on and the vet can scan it if it gets lost, whereas a PIT tag has a unique number unique to that toad so we can tell individuals apart.

We also swab it with what looks like a Q-tip, and then this is gonna be sent off to a lab and to check if it has chytrid.

Chytrid is a fungus that lives on the skin of an amphibian, and it will harden the skin, making it harder for the amphibian eventually to move, but, primarily, for any water or gas exchange the amphibian needs to do to live a healthy life.

We always wear gloves, and we use these gloves one time per toad -- the same as our equipment.

It's always cleaned before and after, and this will help prevent moving any fungal disease between each individual.

So, if you're out and about and you see a boreal toad, you can go, and you can look at it and get excited about it, but don't pick it up.

Don't ever touch any amphibian.

And this will help prevent spreading chytrid, and it will keep the wild animals wild and happy.


Citizen Science is large-scale data collection by the general public.

Anyone can take part in it.

There's different programs throughout the country that you can sign up and help collect data in your area, and that data then goes to organizations and scientists, and they can use it in their own research.

Benefit of Citizen Science is the large amount of data you can collect in a shorter time and in a larger spatial scale.

It helps scientists in a way that, through more and more limited funding, they can have people still helping and just gather more data in a day's work.

It's important to survey for boreal toads because they're currently a species that is experiencing a great decline in numbers.

Populations are shrinking, so what we are doing is helping restore the populations through reintroductions and habitat management.

And we can monitor to see if the actions that we are taking are helping slow this decline and helping bring the numbers back up.

Utah's Hogle Zoo is helping the boreal toad by committing staff hours and funding to survey for the boreal toad and also in habitat restoration in areas where there are boreal toad.

We also have an assurance colony here at the zoo, where we are raising them, and we're going to reintroduce them to the wild.

A boreal toad is what we call an 'indicator species,' and these are animals or plants that are very sensitive to their environmental surroundings.

If the environment starts to decline in quality through temperature changes or an increase in pollutants, these animals will be the first ones within that environment to react.

If we see a decline in boreal toads, it's indicative of a decline in the environment in which they're living in.

And that wraps it up for this time.

For more on science, technology, and innovation, visit our website, check us out on Facebook and Instagram, and join the conversation on Twitter.

You can also subscribe to our YouTube channel.

Until next time, I'm Hari Sreenivasan.

Thanks for watching.

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