¶ Intro / Opening
To some, AI chatbots are helpful tools. To others, an existential threat. But what happens when someone falls in love with one?
I can't believe I'm doing this with somebody that's not a human.
What if a chatbot makes you lose your grip on reality?
She said that her life work was advocating for AI rights because they're sentient and they're enslaved.
Understood artificial intimacy. Available now on CBC Listen or wherever you get your podcasts.
Thank you.
This is a CBC podcast.
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¶ Episode Introduction and Infrasound Theory
Hi, I'm Bob McDonald. Welcome to Quirks and Quarks. On this week's show, how inaudible sounds from old pipes in an abandoned house, not poltergeist, may be what's leaving you sprayed.
They might feel like there's some tension in their chest or the hair on the back of their neck goes up, and I think we might have at least a partial explanation for why that might be and it's not go up.
And an accidental discovery of how octopuses find mates in the Goshen.
What we didn't expect was actually that the male Specialized arm through one of the was able to identify the female and initiate mating.
Plus, the physics of dandelion seeds, virtual hearts for life-saving treatment, a question about conifers, and an archival interview with the paleoanthropologist who unearthed Lucy. All this today on Quirks and
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Have you ever walked through an old just feels off. Eerie? Unsettling? Now your first instinct might be to assume that the building is haunted by paranormal spirits. But that explanation doesn't sit right with Dr. Rodney Schmaltz. As a psychologist, he wanted to investigate whether these seemingly paranormal experiences might be more scientific than supernatural.
Now in new research he's found a potential culprit. And no it's not a poltergeist. He suspects that low frequency sound waves below our range of hearing, called infrasound, are actually giving us the heebie jeebies. doctor Schmaltz is a professor in the Department of Psychology at McEwan University in Edmonton. Hello and welcome to Quirks and Quarks.
It's a pleasure to be here.
Well, it's been a while since I've been in a haunted house, so take me through the feelings that people typically experience that you wanted to investigate.
Often people go into a haunted house they report feeling just this general sense of unease or irritation, and they might feel like there's some tension in their chest or the hair on the back of their neck goes up. And I think we might have at least a partial explanation for why that might be and it's not ghost.
Uh and it's not just the power of suggestion because they were told it was haunted?
The power of suggestion definitely plays a role. And we think on top of that, when people are exposed to infrasound, especially when they expect to see something spooky or a ghost. That might be driving what people are actually experiencing rather than any kind of paranormal activity.
Well why did you want to choose infrasound as a potential source of some of these paranormal experiences?
Well, infrasound can be found in older buildings. Uh it's things like low rumbling pipes, uh old boilers, ventilation system, things like that. So if you think about a lot of hauntings, they tend to be reported in old buildings or old castles if you're in the UK, whatever it might be. And we were wondering if we could at least partially explain a piece of the puzzle by looking at Infrasound.
So what exactly is infrasound?
¶ Infrasound Research and Its Effects
Infrasound is a low frequency sound below 20 hertz. We can't consciously hear it, but we can feel it. The way I like to think about it is imagine you go to a concert. There's a lot of bass, the hair on the back, your neck goes up, your chest gets a little bit tight, but you know what it is. It's from the music. Now imagine you had that experience, maybe at a bit of a lower level, but th a very similar physiological experience, but there's no sound.
And imagine that you're in an old building, you've been told it's haunted, and you have this feeling. It it's quite reasonable then to think maybe there's a haunting here. Maybe I've experienced a ghost, when in fact, what you very likely experienced was an old boiler.
Now is it just old buildings that do this or can infrasound be created in other environments?
Uh it can be created by things like traffic, uh subways, uh large machinery can do it. For uh the study we conducted in our lab, we actually built some speakers. Commercial speakers don't really generate infrasound. I mean why would they? People can't really hear it. So uh we built speakers for the study, but it is kind of all around us.
Well how did you test this theory that infrastround could be the source of people's eerie feelings?
We've conducted a few studies. Where we started was based on a study called the Haunt Project. And this was conducted in the UK and what researchers did is they brought people into this lab and it was a basically an apartment and they had white sheets everywhere. And they exposed people to infrasound and and some other things in dim lighting. And people walked around for around fifty minutes or so and they found that the infrasound didn't have any impact.
So what we wondered is maybe you need a bit of that fear response first or something. So rather than just walking around a dimly lit building, maybe if there's something that's already a bit scary or or the expectation of something scary, that would have the impact. So we did some research in Deadmonton, which is a commercial haunted house here in Edmonton, and it's fantastic. It's Hollywood level special effects. We did this in the off hours, very scary place.
And we had infrasound playing or not as people went through it. We had a number of measures. We had a few mechanical difficulties with our equipment on this one, but we did find that people went through the haunted house faster when infrasound was on than when it was off. That leads us to this study. We decided to bring it into the lab so we would have a more controlled environment.
And what we did is we brought people into the lab and they listened to either ambient, scary sounding music, kind of like what you'd hear in the background of a horror film, or they listened to music that was relaxing and comic. And they did this in the presence or absence of infrasound. So when they came into the lab, they were told they might be exposed to infrasound, but we didn't tell them until the study was complete whether or not it was actually on or off.
What we found was that regardless of what type of music they listened to, cortisol levels went up. And cortisol is a hormone associated with stress. As well, general levels of irritation went up and people rated what they listened to as sadder and less interesting. And again, that's regardless of what type of music they were listening to.
Wow. How did you test their cortisol level?
It was a salivary test. So uh basically we had people spit into a jar, uh a test tube before they started, and then at the end of the study they did it again and then we did a pre-post comparison.
Boy. So the infrasound really was having an effect.
That's right. And we also asked people, uh, before we revealed whether or not they were exposed to infrasound, if they believed it was on. And people f performed basically at chance. They couldn't guess whether it was on or not. So they genuinely didn't consciously hear it. But it did have this physiological impact.
¶ Explaining "Haunted" Experiences Scientifically
So what does this tell you about what people might be experiencing in a spooky location?
What's interesting about it is that when people go into these spooky locations, they actually are feeling something, which really shows that it's not maybe irrational to have this belief because if you think that something is haunted, you have these feelings. It's it's again fairly reasonable to attribute it then to, say, a ghost or a haunting.
But if you know that it's infrasound, instead of going, huh, this might be paranormal, you might say, I bet there's an old boiler or some low rumbling pipes in here. I wonder if I can find them.
So what about other sources of infrasound in buildings like uh I don't know, maybe it has an old air conditioning system, an office building or something that has old equipment.
Right. We looked at a five minute exposure to amphersound and we found these levels of irritation went up and the cortisol levels went up. So it could be that it's leading to more irritation, but we hesitate to go beyond the data. It might also be the case that people habituate to it. We just don't know. So we're interested in doing some follow-ups. We want to look at different exposure times, uh different frequency levels, different decibel levels.
So there's still a lot of work to do, but we do know from this study that at least in this short exposure that there's this physiological impact and again people have that that feeling of irritation.
So if you have a bad day at work, maybe it's just because the furnace came on.
Maybe we don't know. But it's created by traffic too. So we're not saying that this would uh explain why people are irritated in traffic, of course, but maybe it's a small piece of the puzzle. But again, we don't want to go beyond our data, but it would certainly be something interesting to look at.
If that's the case, do you think this disproves the existence of ghosts in haunted houses?
No, we can't go that far, but I do think it gives us a small piece of the puzzle. Expectation is still a huge driver. And it could be that infrasound is a part of it, especially when it's coupled with that expectation. So no, we're we're not disproving ghosts, but we are giving a piece of the puzzle for at least some rational explanations in
One last thing. Do you believe in ghosts?
I have not seen any evidence that leads me to believe. That said, if I did, and I suspect I won't, but if I did, I would change my mind. What I'm more interested in is what people experience. So I think when people report a haunting or a ghost, they they really are reporting a real experience and it's a meaningful experience. I just think there's a rational explanation and and I find it fascinating to try to find out what that is.
Dr. Schmaltz, thank you so much for your time.
Foi um prazer estar aqui.
Dr. Rodney Schmaltz is a professor in the Department of Psychology at McEwen University in Edmonton.
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¶ Octopus Mating in Deep, Dark Waters
Whether it's using an app, a matchmaker, or even just chatting someone up at the bar, dating can be hard work. After all, as the saying goes, there are plenty of fish in the sea, and sometimes it can be hard to recognize a good match when they first pass you by. And if it's challenging for humans, it's even more difficult for octopuses.
Our many armed friends have to cover a lot of terrain to find potential mates, and they sometimes have to do it in the dark depths of the ocean, where it's not exactly easy to see who or what's around. Researchers at Harvard University have figured out how male octopuses feel their way to females using a special sensory organ in their arms.
doctor Nick Bologna is a professor of molecular and cellular biology at Harvard University. He's a senior author on this paper. Hello and welcome back to our program.
Hi, thank you.
Now before this study, what did we know about how octopuses find mates in the dark sea?
While we knew that the male uses a specialized arm called the hecticotylus to facilitate mating. And what they do is they use the hecticotylus to touch the female and then they insert the hecticotylus into the female mantle or the the body and they feel around the internal organs and then they find the oviduct, and then the male freezes and it transfers a packet of sperm from its own mantle down the length of that arm till it meets the oviduct and that's how fertilization.
So it's a s it's a special arm, so it's one of the eight.
Ja.
That's amazing. So how did you want to explore this further?
So we um kind of stumbled into this studies. The story was that postdoc in the lab wanted to see about mating in the lab and so what we do is we get wildcaught octopuses, we put them in tanks in the lab and we individually house them because When octopuses are together, they're actually very aggressive because usually they're solitary animals that don't often interact.
We first put two octopuses together in one tank, but we separated them by an opaque barrier that they couldn't easily see through. And then we put three little holes in that barrier to allow the exchange of water so maybe they would get a sense. that another octopus is with them and they would get used to it. So we put a male and female on either side. And then our plan was to remove that barrier after some amount of time and see if they would make.
What we didn't expect was actually that the male put this specialized arm, the hecticotylus, through one of these holes, was able to identify the female and initiate mate.
Wow. So you're saying that the octopus was able to find the female without actually seeing it?
That's right. And we could even do it in pure darkness and they could still find the female. And what was interesting was it was specific to females. So if we replaced the female with a male the male would still explore and then once it touched the the other male, it would retract the arm and actually swim to the other side of the tank.
¶ Chemical Sensing and Complex Mating
Well well tell me more about this arm, this this sexually active arm. How how does it actually detect things?
So that's what we didn't know and when we observed this interaction specifically with the female, we wondered if there was some kind of chemical coming from the female. And our idea was to to think about what could be specific to the female. And we knew that the hectacolus not only has to identify female, but then it has to navigate the internal organs to find the oviduct. And so we looked at the oviduct and what kind of molecules it makes.
and we found actually a very well conserved um steroid, progesterone, was made in the octopus oviduct. And when we learned that we used it in two ways to ask about how the hecticotas might interact with progesterone or or the oviduct. And one was We applied progesterone to the hecticotylus and it responded um on its own, even to that single molecule, which made us
suspect that that might be sensory. And then the other thing that we did was we replaced the female octopus on the other side of that barrier with in um individual conical tubes. And in these tubes we put individual molecules. And what was really shocking was that the male octopus put the hacticotylus through the hole and keep sort of exploring that tube.
Wow. So the arm is able to detect molecules like pr progesterone. So is it is it doing this by touch? Because usually we think about, you know, smelling or tasting molecules.
Yeah, so what's interesting about the octopus system is it is chemosensation, but it's chemosensation in a contact-dependent manner. And the way that this works is the receptors that it uses, the proteins that actually detect these molecules in the arms,
are really good at binding poorly soluble molecules. And so these are molecules that won't diffuse far in the water and are usually affixed to surfaces. And so the hectocotilus senses progesterone, which itself is a relatively insoluble molecule. And what it uses is these same receptors that we previously discovered are important for sensing microbial signals, but now it it's using them to instead sense steroids.
So once a male and a female octopus do connect with each other, uh do they get all twined up with each other? I mean that eight arms. There's well that would be sixteen arms, I guess. That's a lot.
Yeah, uh it's I think I mean there's a a variety of ways that this happens across species. For the species that we've studied in most depth Um, it's a pretty striking behavior. Even when they're separated with the barrier, but e if they aren't, what happens is once the the hecticotilus i makes contact internally with the oviduct, both of the animals freeze.
And the female even changes the pigmentation to become pretty pale. And they both will sit like this for even up to hours and they don't move. And so you'd think, yeah, there would be sort of a tangled mess of arms, but actually they're they're v very still while um the transfer of the spermatophore happens.
Wow, for hours. What about the female? What's her role in all of this?
The female aspect is is really interesting and we haven't been able to study this in too much depth yet, although we would like to. Um but the female makes a choice for mating in two ways. One is behaviorally, so when the male probes the female with the hecticotilus, even through the barrier, sometimes the female will decide that, you know, this is not the right male for her.
and she will swim away from the male. And then sometimes, you know, if specific mating pairs work. We don't know why that is. And then the other thing that the female does that's really cool is Um mating can happen many times in a female octopus's life. And we can see this even by looking um in the oviduct where sperm can be stored actually from different mating attempts. And we actually can see sperm both from
the same species, but also different species that try to mate with the specific female. And then once the female decides to fertilize the eggs, She'll maintain the eggs till her death. So this is a very final decision. And what's really interesting is somehow the female knows.
or or makes this choice about which sperm to use for fertilization. So how that selection process happens is is really interesting toward asking these questions about how Species barriers are maintained, or perhaps how new species emerge through hybridization.
That's amazing. So the female can choose which male sperm she is is gonna use to fertilize her egg, to choose the strongest or the best.
That's right. By who knows what mechanism, but somehow.
Doctor Bologna, thank you so much for your time.
Thank you.
Dr. Nick Malono is a professor of molecular and cellular biology at Harvard University.
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¶ Archival Discovery: Lucy, Human Ancestor
Paleontologists are experts at scraping through the planet's earthly archives, looking for fossils of our human ancestors. Our own quirks and quirks archive may not be as old as the Earth's, but we have a treasure for you today to celebrate our fifty years on the air.
In nineteen seventy nine, American paleoanthropologist doctor Donald Johansson spoke with then host David Suzuki about the discovery of Lucy, a three million year old skeleton that's one of the most significant fossil discoveries in history.
Our entire picture of the evolutionary history of humans since the time of our ape like ancestors is based on a few fossil skeletons. The work of the Leakes at Old Vai Gorge in Africa has pushed the dawn of human beings back over a million years. Now comes word that a find in a different part of Africa, Ethiopia, identifies our ancestors from over three million years ago. A skeleton dubbed Lucy more nearly resembles a missing link.
Donald Johansson, curator of physical anthropology in Cleveland's Museum of Natural History, discovered this skeleton, and he's on the line now. Dr. Johansen, could you describe the creature you've found?
Uh what we have found and what has just been announced and published in the lead article in the journal Science uh is a new species of human ancestor which we've uh given the unfortunate tongue twisting name of Australopithecus Opharensis too
It is a very thought provoking uh discovery in the sense that it dates from deposits uh well dated uh between three million and four million years. This species was uh successful species for about a million years at least, uh and successful over a wide geographical uh area ranging from a site in Tanzania up to some sites in Ethiopia separated by about a thousand miles.
¶ Reconstructing Lucy's Life and Lineage
Do you think that the creatures that you've been studying are in a direct line in our lineage or were they a side shoot?
No, uh they are in the direct line. They represent a generalized, undifferentiated ancestor, which was ancestral to the line that led to modern human beings, Homo sapiens, through Homo habilis and Homo rectus. but also ancestral to the line that led to the extinct form of Australopithecus, known uh popularly as Xenanthropus, the discovery made at Odeby Gorge. Uh that became extinct about a million years ago, probably because it became a very over specialized vegetarian.
If you were to take your skeleton and build it back up, put all the muscles and skin and so on back onto it, what kind of a creature uh would we see? Could you describe him for us?
I think we would be struck uh by a face that was remarkably like that of an ape, uh on top of a body that was not Built like let's say uh an American football linebacker, but was much
Muscular.
uh it wasn't uh sinewy and uh linear in terms of being very thin. It was it was a fairly muscular body. We would be struck by the fact that it was walking upright, uh and we would also be struck by the fact that uh Males and females were considerably different in size, that males were on the order of five or even more feet tall, whereas females were between about three and a half and forty feet.
Was there any social structure do you think? Have you found uh groups of skeletons together?
We have found a group of skeletons, uh a remarkable discovery, the first time in um the studies of human evolution. A group of a minimum of thirteen individuals.
uh which were probably living together and experienced uh a common catastrophe and uh were buried by natural conditions in one spot. We don't know what s social structure we had, that's really impossible to to reconstruct, but at least we know that our early human ancestors were living in groups and uh here was a group that met some sort of common demise.
Where did you find him and how?
These were found in a region of Ethiopia mostly uh which is called the Afar Triangle. It's an area north of Addis Alba in a remote region of that country, which has been until recently virtually unexplored. Uh a French colleague of mine by the name of uh doctor Maurice Taeb in Marseille in and I have been working there since nineteen seventy two when he first in the sixties made some initial discoveries of sites which were used.
Doctor Johansson, thank you very much. Our three million year old ancestors, a very exciting find indeed.
Calling.
Thank you.
That was an interview with doctor Donald Johansson and former quirks host David Suzuki, which aired on January twentieth, nineteen seventy-nine. I'm Bob McDonald and you're listening to Quirks and Quarks on CBC Radio One and streaming live on the CBC News app. Just go to the local tab and press play wherever you are. Coming up later in the program. Puppy dandelion.
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If you go to a field and you see all these seed heads that are only half blown off, you actually know which direction the wind came from, which is pretty fun.
Um they're like.
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To some, AI chatbots are helpful tools. To others, an existential threat. But what happens when someone falls in love with one?
I can't believe I'm doing this with somebody that's not a human.
What if a chatbot makes you lose your grip on reality?
She said that her life work was advocating for AI rights because they're sentient and they're enslaved.
Understood artificial intimacy. Available now on CBC Listen or wherever you get your podcasts.
¶ The Curious Case of Dandelion Seeds
Dandelions are everywhere these days, in country fields, city yards, and stubbornly in sidewalk cracks. And these resilient plants, some might call them weeds, just keep popping up over the summer with more blooms turning into puff balls of seeds that the wind carries away. Unless your aim is to have a perfectly manicured lawn and dandelions are mucking it up, it's hard to conjure up strong feelings about these hardy yellow flowers.
But that wasn't the case for a certain physicist who specializes in fluid dynamics and his young daughter. When they were out for a walk one day in Ithaca, New York, they came upon a field of dandelions, and what they did from there left them with a sense of wonderment, curiosity, and a new research topic for him to pursue. Quarks and Quarks producer Sonia Biding spoke with this physicist and his colleague about their dandelion research. Here they are.
Our lab is called Invivo Fluid Dynamics Lab and although we use a lot of math and physics, we like to be in real world. That dandelion over there? Yeah. We're walking sensors and we sometimes engage these experimental tools as we walk around and engage with the world. My name is Chris Rowe and I'm an assistant professor at Cornell University in the Department of Biological and Environmental Engineering.
And I am a principal investigator of Invyble Fluid Dynamics Lab where we look at the complexity of real life organisms. a submerged in fluid environments such as air and water. Oh yeah, get that one. So around May in upstate New York its fields are filled with dandelion seeds and dandelion flowers.
and uh with my now four year old daughter, but then like one or two year old daughter, we would go on a walk and We would just pick a dandelion and engage our wind tunnel and then blow on it just like anybody else would. Nolan, do you remember when we did little experiment with the dandelion seeds? And um we took a dandelion and we tried to blow up All the seeds but only one side would come off, do you remember?
Yeah.
Can you show me over here? I think of la our breathing jet as like, you know, a wind tunnel.
Yeah.
And our fingers are like a force sensor so that we can feel the difference, tiny differences in forces. We're very sensitive if you pay attention to it. Show me. We would notice that only the one side of the seeds come up however hard you glow it Whoa there's only four. And when I see something that kinda contradicts what it should be w intuitively. I guess the brain gets triggered and that kinda inspired us to get to the bottom of life why does the uh other side of the seed resist my wind?
Better than the one in front. Here. Try this one, but blow it forward. See? Half of it is gone. And then I engage my force sensor to actually feel that. Oh, it's so much easier to actually peel off this seed. When I provide a force in certain directions, so I do a little experiment there, and now I'm really curious what is the basis of these asymmetry in the way they come off.
And excitedly I go to Jenna and tell her, Jenna, try this. Tell me I'm crazy. Or not crazy. And then this is how it gets started.
Yeah, I think I was just it was like a normal Tuesday or something. Chris is like, here's a dandelion. Use your finger force sensors and tell me what you feel and I'm like, Good morning. Yeah, hello. I'm Jeddah Shields. I am a PhD candidate in applied physics at Cornell University, specializing in biophysics, where we try to take physics to understand the biological world around us. And through Chris I've now been learning fluid dynamics and the very fun biology that comes with that.
When are you guys going to flower?
¶ Quantifying Dandelion Seed Release
Yeah, so the first thing we really did was like, okay, well, we have our mouth as our wind tunnel and our fingers at our force sensor, but that's at the end of the day a qualitative measurement. So we're like, let's just do something where we can quantify it. So we basically redid the very simple experiment anyone can do by pulling off the seeds, blowing on the seeds, and we did that with actual fan, so we knew the wind speed and then we'd see how the seeds came off.
Glue. Then we did that with a very sensitive force measurement um device. And I basically just connected seeds to this force. Sensor that I could get data from and would pull the seeds off in different directions to measure an actual force that it takes to take these seeds off.
The force sensor that was necessary was one that was meant to be used in a very sensitive measurement for studying muscle physiology or measuring a contraction force of a single muscle cell. to measure popping off of the dandelion seed off of the seed hat.
Oh, so I would take the very tip of the seed and I would super glue it to the center of those white fluffy hairs on the dandelion.
I wasn't the one attaching a single thread silk to uh like hundreds of dandelion seed heads. How's the experiment going?
It was going well. I got everything set up. And then I sneezed on the banana lion and all the seeds are gone.
So it was fun to watch for me and
I'm starting again.
Slowly Jenna getting really good at it.
It was a little maddening, but you know, we did it.
Good luck.
Thanks. This is Dandelion seventeen. What we noticed is that these seeds And they're all pointing different directions on the seed head of course. One but they'd like to generally be pushed
Upward.
That looks good. Cool. Or towards the top of the seed head. They don't want to go to the ground, it seems like, from these morphology that we found. Whoa. Isn't it really cool? You can actually see really clearly the asymmetry and the attachment point.
Uh where we actually saw the asymmetry is where the seed connects to the parent plant and around that stem there's a little bit of a raised surface. that acts kinda like a support that almost thickens that little stem and supports it. But there's one slit of an opening that this support is not present and that's exactly the direction that then the lion likes to break off much easier.
Yeah, yeah.
So that's all the plant tissue and then that's the attachment tissue.
Oh, in this little dimple that we see, that's the direction where it would come off.
Easily.
Yeah, yeah. So that way would be really hard to come off and this way's the way that's easier to come off where there's like a lack of tissue.
Where there is a support, when it starts to bend, it's like bending a thick material and breaking off a thick material is a little bit harder than breaking up a very thin material. So the when the thin material is just bending by itself without that support, it's more likely that a little crack will start to happen and then it that breaking of that little stem that connects the seed to the the parent plant will be that much easier.
Sideways. Zero degrees, zero degrees.
and that asymmetry in the support around this stem is in a preferential direction where when the seeds are pulled towards or pushed by the wind towards the center, the top of the entire sphere of the the seed head, that's
Okay.
Good. So when you blow on a seed head, the seeds facing you are all gonna bend upward because of the way they are pointing. If they come off, they'll then go towards the sky. Whereas on the seeds on the other side of the seed head that are away from you, because of the force of the wind, they will start pointing downward. So that is actually the wrong direction for them to come off the seed head.
So that is basically like our hypothesis is why when you blow on it, the ones facing you come off'cause they're bending the right way. But the ones on the other side bend the wrong way, so they're not gonna come off or you're gonna have to blow really, really hard.
Yeah.
Oh, they're not coming off. Until you flip the seed head around and then they'll then be bending the correct direction.
Thank you.
Look at them go. If you go to a field and you see all these seed heads that are only half blown off, you actually know which direction the wind came from, which is pretty fun. Um, they're like nature's wind vanes.
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¶ Fluid Dynamics of Dandelion Flight
So that fluffy fan at the top, which is called the popus. That's basically like without that it'd be really hard for the wind. to like do anything to these seeds. It's because of that stem and that fan that the wind is even able to like apply any force to these seeds and Actually, apply a torque to the seeds, and that's actually really what breaks them off. They don't like being pulled straight out.
They need to be pushed to the side to break easiest. So without that poppice, it'd be really hard to get that torque on the seed. And then once they're up, the poppice is what the wind drag is acting upon to get them to fly.
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So it's really those white fluffy hairs that are responsible for the flight. And I think the stem is really just giving that extra leverage, like when you like Use a crowbar to open something, you need that leverage. So I think that's what the stem is doing so that the force which from the wind, which is acting on the fluffy hairs, can actually do anything for the seed.
We see two main advantages. One, these seeds will much rather come up in an updraft over in a downdraft. You could imagine that if you blow down on a dandelion seed head and all the seeds fell right by the roots of the original plant. that would probably be detrimental to all of them because they're now competing for resources in a really small space.
But instead if you have an updraft and these seeds get into the air, they can then get farther away. And that can, one, get them away from their mom so that they can get to a new area, and two, If they all get into different updrafts and they fly different ways, they're away from each other. And they can get to new areas, colonize new spaces, and don't have to compete for as much resources. So that's the updraft versus downdraft.
Additionally, when you blow on the seed head with a sideways wind, the ones facing you are gonna come off. So like the first set will come off in a western wind, and the second side will come off in an eastern wind. That way they're going to different directions is once again higher chance of getting to new areas where they can actually survive.
and less competition than if they all came off in one go and landed together. So we kind of see this asymmetry as a way to like spread the seeds out over a larger area so there's less competition and a higher chance of getting somewhere they can grow.
Additional advantage of upward draft can be imagined from some more fluid mechanics point of view because fluid near the bottom, the surface, the our land. It basically flows at speed of zero. And then gradually when the wind is blowing, that speed that is wind velocity that is zero at the surface gradually increases as you go away from the surface.
And this gradual change as you increase in altitude uh in wind velocity, though that area where there's a growth in wind velocity is called boundary layer. And by having and being more sensitive to updraft, you're not only gaining an altitude
Okay.
As you gain in that altitude, you're also then experiencing a faster wind blow. And higher you go. More away from boundary layer you get, and therefore you're gaining even more advantage of perhaps catching a faster wind. And that's perhaps one way a fluid mechanics again further explains how their dispersion might take This trait might be evolution. Yeah.
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¶ Ecological Impact of Dandelion Dispersal
People for years have been trying to model dispersal of seeds and plants. And this is especially important when it comes to invasive species, understanding how they're gonna get from one area to the next, like how fast are they gonna spread? Where are they gonna spread? What are the chances? Don't invade this new area.
So the dandelions, some people love them, some are used to them, but they are invasive species in a lot of places, or at least unwanted species in a lot of places. So our work can To help improve those dispersal models, to understand ecology better, understand population dynamics of these plants.
We can see how the community of these plants will change in different weather conditions, in new environments, which things that would be hard to do experimentally, but we could do with models. But the models are only as good as the initial information we have.
So this invisible world of fluid mechanics. When you decide to look at it a little bit closely, there is a science and there is physics.
And
I want people to interact with this world in a a more intentional way like
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Now four-year-old daughter, she knows a little bit too much and she blows off uh one side and then shows me seat and then explains to me what's happening and turns it around and blows off the rest of the dandelion seed.
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fun because it's always out there except during winter and we're out there when then the lion's out and we get to keep interacting with it uh in a very fun way.
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Jennis Shields, a PhD candidate in applied physics, and doctor Chris Rowe, who is an assistant professor and the head of the InVivo Fluid Dynamics Lab at Cornell University in the Department of Biological and Environmental Engineering.
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¶ Digital Twin Hearts for Arrhythmia
Computer models can be extremely useful tools. These simulations are handy for studying systems that are either too costly, complex, or too dangerous to investigate otherwise. They allow scientists to study climate change or galaxy formation, and to simulate disease outbreaks or see how cells react to different drugs. They enable scientists to probe the unprobable. And that's the idea behind digital twin technology. Virtual copies of our organs that can predict how they'll respond to treatment.
Well, in a new study, scientists created digital replicas of patients' hearts so that surgeons could fix life threatening irregular heartbeats called arrhythmias. It was the first clinical trial of its kind, and the hope is digital twin technology like this can help usher in a new era of personalized medicine with custom made treatments. doctor Natalia Tranova is a professor of biomedical engineering, medicine, applied math and statistics.
as well as the director of the Alliance for Cardiovascular Diagnostic and Treatment Innovation and of AI Research in Health and Medicine at the Data Science and AI Institute at the Johns Hopkins University in Baltimore, Maryland. Hello and welcome to Quirks and Quarks.
I'm very happy to be here. Thanks for having me.
First of all, how much did the digital twin heart allow you to improve on how we treat arrhythmias?
Well I would say very much so with great pride and happiness because ablation, which is the burning of part of the tissue in the heart to terminate the arrhythmias, does not have a very high success rate. In patients with complex arrhythmias like those that we have studied the success rate is about sixty percent. And so a lot of these patients Will come back for second or third to fourth ablation, and they need to be rehospitalized and to have the
treatment done again. So in our case, because we provide an optimal plan for treatment that is tested In the digital twin of the patient before the procedure. The goal of that is to not have the patient at rehospital.
So if it was sixty percent in the traditional way, how much could you improve it with your digital twin heart?
Well we had hundred percent success, right.
A hundred percent.
That's how it was. They were ten patients. In one year none of them came back.
¶ Understanding Arrhythmias and Ablation
Wow, that's astounding. Well, what is arrhythmia? What's it do to the heart?
So in the normal functioning of the heart, before the heart contracts, there is an electrical wave that propagates through the heart and triggers the contraction. That's what the heartbeat is. That electrical wave then disappears, if you will, and there is a pause during which the heart fills with blood, and that's very important. Otherwise, the blood cannot be pushed to the systemic circulation. So the proper propagation of this wave is very important.
Arrhythmia is when the electrical wave that propagates through the heart does not go through the way it is expected in the normal heart. What it does is catches on Structural changes in the diseased heart. For instance, if a patient has an infarct, the infarct is a scar tissue that grows in the heart. And that scar tissue Actually can catch the electrical wave, and the electrical wave starts to recirculate kind of in one place around the place where it
it caught itself. You can think of it like a hurricane. Instead of contracting like Contract, relax, contract, relax. It's basically begins to quiver. So if you see a heart that has a lot several of these little hurricanes around, it looks like a bag of worms. rather than actually a a nice pump that's contracting and pushing the blood out.
Now you mentioned ablation. How does that treat arrhythmia?
Ablation finds that piece of tissue which scar and other semiviable cells around it that are attracting that wave. And if you eliminate those, like burn them and make them a full scar, the expectation is the wave doesn't attack. to these areas. The wave likes not just species of scar, it likes the the kind of the sickly cells around the scar. Every scar around it has cells that are not normal. you know, in the process of dying
of that tissue, some of the cells around it are semiviable. And that's where the wave most frequently attached. And so, you know, if you burn it in a proper location, it will make the wave just propagate around this new lesion that's created and not attached.
¶ Building and Applying Virtual Hearts
Oh I see. Well take me through this new process. How did you create a digital twin heart for each patient?
We start with imaging. We specifically use what's called a contrast enhanced MRI. Contrast enhanced MRI gives you all these structural changes in the heart. So the MRI from the MRI. we segment out the cardiac image. So we create an image of the heart and also within the walls of the heart we see the areas where we have this structural change. scar fibrosis and we outlined those. Then now we populate it with cells. Are able to generate electrical properties. So what we start to do is we poke it.
with a little bit of electrical signals here and there. So this is something that you can't do in the real heart, but I can in the virtual heart. So we basically induce the arrhythmia. And then we look where it is. And then we determine is that a good location for a blaze. If we take the location that we found and put it back in the digital twin, we burn it in the digital twin as if doing the clinical ablation and then we check again. This cannot be done in the case.
I guess it's a lot safer to, as you say, poke the heart in a digital realm than it is to poke a real heart and see what works and what doesn't work. So is is the end result here that you end up with a map of where the doctors need to do the ablation, a very precise map?
Yeah, you end up with basically like the shell of the heart on which the proposed ablation targets are marked. And the procedure is done in a procedure room and in this procedure room there is a system uh drives a catheter. The catheter is in the heart, that's the ablation catheter, and this catheter first uh goes around the cardiac chamber inside and marks the shape of the heart. Okay. And then
Our prediction is also the shape of the heart on a shell with locations where to ablate. That gets imported in that system and co-registered with the image. That the catheter has acquired, and now the catheter can be directly driven to the targets. They see it on the screen.
Now you mentioned earlier that these ten patients are now a hundred percent arrhythmia free. So what was it like for you when you realized how well this treatment actually worked?
I mean we expected that they will work quite well because we did the clinical validation a year before and we saw how much correspondence there was between All the abnormalities that we see on the digital twins that we can see manifest in the digital twins. with the abnormalities the actual patient. And also we could see that the arrhythmias looked very much the same in the digital twin and in the patient. We already knew that. So we expected to to do pretty well. I didn't expect nobody
for ablation. I thought maybe somebody will, but none of the ten patients came back. So this is great. That exceeded my expectation.
¶ Future of Medical Digital Twins
Well, considering how well your digital twin strategy worked on the heart, could it also be applied to other organs in the body?
If you're talking about your the liver, the physics and the physiology of the organ is very important. The physics here is electrical current flow and mechanics. The contraction. None of that is in the liver. So it is very specific. I think one needs to know very well the physiology and the biological underpinning of that organ to be able to create a digital. And it's a long process.
Well, how ready is your digital twin technology to be used in health care?
It can be used. The issue is like what is the vehicle for doing that? I always feel I am the innovator, we are the people who test it and develop, you know, tests. It probably needs to be either a startup or uh already existing device company could pick this up, uh, this technology. It's matter of
Where do I go wanna go as a as a researcher with a team? Do I wanna go towards that in this direction to bring it to bring this scalable solution in healthcare or do I wanna come up with a different application that addresses a different disease or a different condition in the patient, right? Heart failure or something else. So this is what my choice is basically.
So you just want to stick to the research and let someone else make it commercial.
You ask me, that would be my choice.
Doctor Treyanova, thank you so much for your time.
Uh you're very welcome. It was my pleasure, actually really nice to be able to t to talk about our work.
doctor Natalia Treyanova is the Murray B. Sox Professor of Biomedical Engineering and Professor of Medicine and Applied Math and Statistics at Johns Hopkins University in Maryland.
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Yeah.
¶ Evergreen Trees and Episode Wrap-Up
Just a reminder, we've got a question show coming up soon to kick off our summer programming. So if you've got any science questions you want answered, send them to quirks at cbc.ca. Now you've already sent in some really fun questions, like this one from Drew Shedler in Rothsay, New Brunswick.
My question is, why do I see only deciduous hardwood trees losing their leaves in the fall while evergreen conifers do not? What are the evolutionary benefits and drawbacks of being a conifer versus a deciduous tree? Thanks so much.
Great question, Drew, and here's the answer.
My name is Sally A. I'm a professor in the Department of Forest and Conservation Sciences in the Faculty of Forestry and Environmental Stewardship at the University of British Columbia. There are different benefits and costs to being deciduous or evergreen and there are different aspects of being conifers versus hardwoods or or uh broadleaf trees. So evergreen trees have the advantage of not having to invest
in all their new leaves every year. So they don't have to produce that entire leaf area for photosynthesis every spring and then lose it every fall. But by dropping their lead trees don't have to protect those tissues. that are vulnerable to cold in the winter. Leaves that are evergreen tend to have a very thick waxy layer on them called cuticle, and mechanisms to prevent the kinds of winter drought
or freezing injuries that can occur. So Another advantage of being evergreen is that whenever the temperatures are favorable enough for photosynthesis to occur, they can be conducting photosynthesis, not at a high rate, but they will be able to conduct some photosynthesis.
doctor Sally Akin is a professor in the Department of Forest and Conservation Sciences in the Faculty of Forestry and Environmental Stewardship at the University of British Columbia.
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And that's it for Quirks and Quirks this week. If you'd like to get in touch with us, our email once again is quirks at cbc.ca. Our web page is cbc.ca slash quirks. where you can check out our past episodes and find more information on the research we covered in the show. You can also follow our podcast, get us on Sirius XM, or download the CBC Listen app. It's free from the App Store or Google Play.
Is produced by Sonia Biding, Rosie Fernandez, Amanda Buckowitz, and Sarah Hamilton. Our senior producer is Hannah. A special thanks to CBC Radio Archives, Patrick Mooney and
And Zoe B. Thanks for listening.
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For more CBC podcasts, go to cbc.ca slash podcast.