Welcome to STEMology – Show Notes

Season 1, Episode 15

Citizen juries, Maths and the brain, Kirigami drug delivery and a Blue-eyed ancestor

In today’s episode of STEMology…

How Citizen Juries are being formed to help make the big decisions, a study that discovered that maths is key to brain plasticity, using kirigami – a form of origami – to deliver drugs in the body, and how all blue-eyed people can be traced back to a single ancestor.

Citizen Jury

how groups of non-specialists, properly guided, can provide intelligent, reasoned and insightful responses to complex issues

Maths & brain development

Interesting thing that they found was that students who didn’t study maths had lower amounts of a crucial chemical for brain plasticity

Kirigami drug delivery

they say… a stretchable, snakeskin inspired kirigami shell integrated with a fluidic lead driven, linear soft actuator, which I just like saying that.

That’s just some top drawer technobabble

A blue-eyed ancestor

Every single person in the world with blue eyes is a descendant of one person in the past who had a mutant gene where they couldn’t produce enough melanin in their eyes

This is a “kind of, sort of, vaguely close” copy of the words that David & Sophie speak in this episode.

IT IS NOT 100% accurate.  We are very sorry if we have spelt something completely incorrectly.  If it means a lot to you to have it corrected, email us at stemology@ramaley.media


Intro [00:00:00]

[00:00:00] Sophie: [00:00:00] Welcome to episode 15 of STEMology,

[00:00:03]David: [00:00:03] A podcast sharing some of the interesting fun, and sometimes just patently bizarre news in science, technology, engineering, or maths.

[00:00:09]Sophie: [00:00:09] Your hosts are Dr. David Farmer and Dr. Sophie Calabretto. Today, We’ll be talking about citizen juries, why maths is good for you

[00:00:19]David: [00:00:19] Kirigami stents and ol’ blue eyes.

[00:00:22]Citizen Jury [00:00:22]

[00:00:22] So Sophie gene editing is exciting.

[00:00:26]Um, it’s also a bit scary.

[00:00:28]Sophie: [00:00:28] Yeah. I think  it can be depending on what you do.

[00:00:32]David: [00:00:32] Yeah. So there’s all kinds of things we can do with this technology. We can eliminate genetic diseases, but there’s also some concern that we might use genetic editing to do things like make super babies.

[00:00:43] Sophie: [00:00:43] So it’s funny because yeah, in this, we both read the same thing and we’ll get to why we read it in a second, they said that one of the concerns were producing babies engineered for super strength or musicality. And to be honest, I mean maybe if you had some babies that had super strength and other babies who didn’t like, I guess that would be bad for the ones who didn’t, but I don’t know, like a super musical baby.

[00:01:04]I don’t think I’m threatened by that. Or should we just not be messing with people? Is that the idea

[00:01:08] David: [00:01:08] And presumably this is a super musical baby, and that is predisposed to like playing the cello. Not like it cries Claire de lune like it’s not a musical baby in the sense of it produces music when it is a baby.

[00:01:20]Sophie: [00:01:20] Okay.

[00:01:21] So again, this is still even like, if I had a baby that like cried something as opposed to just screaming again sounds pretty positive. So the idea is, uh, genome editing can be, it’s a scary topic. And so we need to talk today about something called a citizen jury or the citizens jury.

[00:01:40] In fact, they met last week at old parliament house, The Museum of Australian Democracy, which I didn’t know was a thing. It sounds like a very exciting place, I might visit in the future.

[00:01:49] David: [00:01:49] Okay.

[00:01:49] Sophie: [00:01:49] And the idea is they got together. So in the press release. They refer to them as 12 dozen, perfectly ordinary Australians, which to me sounds slightly harsh, um, perfectly ordinary. So

[00:02:03] David: [00:02:03] They’re fine. They’re just the, absolutely. There’s nothing wrong with them. They’re fine. They’re perfectly ordinary.

[00:02:10] Sophie: [00:02:10] If  any of those perfectly ordinary Australians are listening right now, we actually think you’re great. All right. You’re not ordinary. You are superb. Everyone is superb in their own way, but the idea is we’re getting this group of people together to have conversations and make minds up about complex issues that the country is facing, like using  sciences, like genome editing.

[00:02:30] So the idea is this is the first jury in a series of juries to be held around the world. And it’s going to culminate in a global citizens assembly in Athens and all of this is based on paper. So it was led by Professor Dianne Nicol, who’s the director of the Center for Law and Genetics at the University of Tasmania and also Professor Simon Niemeyer, the head of Australia’s Center for Deliberative Democracy and Global Governance, University of Canberra. Yep. I don’t know what some of those words mean in that order. and the, this paper analyzed how groups of nonspecialists, properly guided, can provide intelligent, reasoned and insightful responses to complex issues.

[00:03:12] Thus, providing a balanced of opinions advanced by activists and other vested interests.

[00:03:17]David: [00:03:17] Yes. And importantly, the juries are made up of citizens with no history of activism on a, particular issue, which means they’re good at reflecting on the relative weight different values and principles said, Professor Dryzek,  one of the people involved with the study. Um what do you think about this Sophie?

[00:03:32] Like, I started off really skeptical on, I think I’ve come run to it.

[00:03:35] Sophie: [00:03:35] I did exactly the same thing. So when this first came up, I said, that sounds like a terrible idea. And I’m about to be very mean and controversial right now, dave, but I

[00:03:44] David: [00:03:44] yes.

[00:03:44] Sophie: [00:03:44] think on average, people are kind of thick. so when this idea of just getting a group of people who know nothing about a topic to make sort of important decisions, it really worried me.

[00:03:56] Cause I think, you know, I really liked true crime. I think I’ve said that before and, um, you know, There’s a comment in the press release about how the trust that we put in juries in courts. And I just freaked out. Cause I went juries make terrible decisions. People go to jail for life, having done nothing because juries have been convinced by very manipulative and, you know, lawyers who are very good at their jobs.

[00:04:19]You know, and I, when I say people sort of thick, I include you in me in that, sorry, Dave, like we’re all have our biases and

[00:04:24] David: [00:04:24] Sure.

[00:04:24] Sophie: [00:04:24] We all have our things, but Yeah. so I went and looked at the paper and they talked about how they would find this group of people.

[00:04:30] So they talk about you on a minimum of a hundred people, more than a hundred people is better, cause it promotes representativeness, but also increases logistical challenges.And the idea is that these people would be recruited around the world using a process of stratified, random sampling.

[00:04:46] So the idea is you sort of take the population and you break them down into sort of different non-overlapping groups that they call strata. So and if you’re gonna do that for age, for example, you’d have, I dunno, zero to five, six to 10, 11 to 15, obviously we’re not going to ask babies this. And then what you do is you take a random sample from each of those groups.

[00:05:07] And so the idea is you get a nice mix of people across the world, but they have suggested that you would need to, protect the integrity of sampling from political interference and in some places.

[00:05:18] David: [00:05:18] Yeah.

[00:05:18] Sophie: [00:05:18] Random sampling is actually maybe not a great idea, but the fact that they they’ve brought up, that we’re talking about a group of people who you know, they’re relatively non bias.

[00:05:27] They don’t have a history of activism. And that, I think that makes me feel better. The fact that we’ve actually gone, okay. People can be very biased and people coming with a lot of opinions and we’re really trying to start with a neutral clean slate educate them on a topic. And then we’re going to have some constructive debate and ideas coming out of this.

[00:05:46]David: [00:05:46] Yeah,I think you’ve raised several interesting points. the reason I came right into it is we trust people to run the criminal justice system basically. And yeah, sure. There’s going to be some examples where things go awry and I would put it to you that those are probably the examples that are going to be focused on by documentaries because they make for the best story.

[00:06:05]Sophie: [00:06:05] Yeah. Documentaries are more exciting when there’s absolute horror show that’s taken place for sure.

[00:06:10] David: [00:06:10] By and large, most of us are happy that the criminal justice system is bubbling along in the background. And there’s a lot of cases with a lot of evidence and people go to jail and that’s probably the right thing, or don’t go to jail and that’s probably the right thing. And just because we have a jury of our peers, doesn’t mean that expertise is excluded from the courtroom. Right. Cause like in the courtroom you would bring in an expert witness, you would have a doctor or a scientist if it’s relevant to come in and say in my expert opinion, here’s what I think and why. And presumably if you’ve selected this random strata of people, you need to inform them, there’s going to be scientists present to inform them about the pros and cons of the particular techniques are being talked about.

[00:06:48] Sophie: [00:06:48] You wouldn’t get them to do their own research on a very complex topic.

[00:06:52] David: [00:06:52] Yeah. I think so. That’s, why I came around to it because of the fact that we’re not going to be excluding expertise from the process entirely. And yeah, we trust a very large, very important part of our society to this kind of mechanism already.

[00:07:04] And I guess the alternative is just someone in charge, just making the decision. And there’s no guarantee that they’re going to be any better informed.

[00:07:12] Sophie: [00:07:12] that’s true. Like I should add that I don’t believe, you know, that a lot of the decision makers and the policy makers in our country, I don’t believe, are particularly well informed about a lot of things and they are making decisions for biased reasons. So the, yeah, so in the paper they actually sort of quotes three reasons why this is sort of quite important. So the first is, um, first reason concerns the legitimacy of any collective decisions in global governments. And so the idea is like public confidence in technologies in their application are going to be better if the public has been an active part of the, sort of like the decision-making and the regulation around those technologies.

[00:07:49] So, they’ve said that, this is a way that we can include that in our decision-making. The next one is there’s a current disconnect between expertise and public values. And so it’s kind of the why. So the idea is.  It might not be obvious to the public, why we need these technologies or what they would be serving.

[00:08:08] And so involving people in that process and that discussion can sort of bring that out, which means that, you know, you’re not going to get angry at the government for using your tax payer money on something that you think is irrelevant or, you know, unsafe or something. And the third one is just this would generate a lot of considered input into governmental decisions, which I think is just quite good.

[00:08:28] And it comes from that last point where citizens can kind of bring reflective judgment to bear in a way that kind of stakeholders or activists or politicians who have something else that they’re concerned with, then they’re not going to do it. So I think that is a good idea. I think, yeah, the reason that I thought it was terrible in the beginning as I just remember it. So don’t know how many telemarketers you’ve talked to Dave.

[00:08:46]David: [00:08:46] Yeah.

[00:08:46] Sophie: [00:08:46] I remember one distinct time when I was making dinner and a telemarketer rang up and they were from sunrise and I was like, I’m going to stop everything. I need to talk to this person about what I think about growing rice in Australia.

[00:08:58] And I was like, I had this like, you know, very like long discussion with this person because I’ve felt very passionately and angry about the fact that we keep growing rice and other things we shouldn’t in Australia.

[00:09:08] David: [00:09:08] Why should we grow rice in Australia?

[00:09:10]Sophie: [00:09:10] Because we don’t have water, we’re not

[00:09:13] David: [00:09:13] Oh, okay.

[00:09:14] Sophie: [00:09:14] a country with natural flood plains. And all we do is we close up the mouth of the Murray when we do

[00:09:18] David: [00:09:18] that sense

[00:09:19]Sophie: [00:09:19] I mean, I will say growing up in South Australia where we have most of the Murray, but we have not that much of the water because people from New South Wales and Victoria suck it all up and being very controversial today.

[00:09:28] Um, but Yeah. so that’s what I was like, someone’s who does come in, who’s angry about rice or genome editing and this is going to be pointless, but yeah, having read the paper. I think they have thought about this more than obviously I did. And the idea That this particular jury that’s just met is like a real world opportunity to test the procedures and the methods in the paper.

[00:09:47] And then your idea is if it does or doesn’t work, they can kind of tweak it for next time. So it would be, you know, this is the first in many citizen juries, but yeah, I think I have come around to it. And, um, yeah, it’d be interesting to see what they decided.

[00:10:01]David: [00:10:01] Very interesting. Very good stuff.  Maths and Brain [00:10:13]From should we gene to, should we maths? And the answer is maybe you should maths

[00:10:18] Sophie: [00:10:18] maybe you should maths. So this is interesting, Dave, because as a mathematician I wax lyrical about how maths is very, very important for everyone, for various reasons. So if you know, you want to look at it from a scientific point of view, maths is the language with which we engage with the modern world.

[00:10:32] It’s the language behind all science, without maths, you can’t have science without science. You can’t have progress. Blah, blah, blah, blah, blah. But also I, you know, would go out and talk to school students and stuff, it’s like, when you are doing math, you’re actually learning all of these underlying skills that are useful for everything.

[00:10:48] So, you know, we tell them that when you do maths, you’re learning critical and  analytical thinking. You’re learning problem solving. You’re learning how to research, and like do all these things that are actually useful in every single job. Not just if you want to become a mathematician, because I don’t know if I’m actively encouraged people just to become mathematicians, it turns out that researchers at the university of Oxford have actually sort of quantified why it is, important to study math in terms of this kind of developmental stuff.

[00:11:15]David: [00:11:15] That’s right. So what they’ve been doing is looking at the brains of A-level students. So that’s year 11 and 12 students equivalents here in Australia. And basically what they showed was when they looked at the concentration of a particular neurotransmitter in an area of the brain called the middle frontal gyrus, they could successfully predict whether that student had continued to study maths in year 11 or 12, or stop studying maths in 11 and 12.

[00:11:43]Sophie: [00:11:43] Yeah.

[00:11:43] So there’s actually like a chemical difference in the brain. So I think the reason that this worked in the UK, right? So. At, I think it’s 16. You can opt out of maths in a way that you can’t in Australia. So you can

[00:11:54] David: [00:11:54] Yeah.

[00:11:54] Sophie: [00:11:54] I’m done with maths. I don’t want to continue doing math. And apparently that is the same case in India.

[00:12:00] So what was really nice about this is that they could actually examine whether The specific lack of math education in students coming from a similar environment could impact brain development.  They did two different experiments. So there was the experiment with A-level students.

[00:12:15] So they had 87 A level. There were 56 females, 31 males with a mean age of 16 years and 10 months. And that was the maths versus non maths groups. So people taking maths at A levels, people not taking maths at A levels. And they had another experiment. And they had 42 pre A level students. And that was split down the middle. So 21 females, 21 males with a mean age of 14 years and four months. And the difference in this group was there were people who all said they were willing to do math at A level. And people would said that they were not willing to do maths at a level. And all of these, you know, you, you question how you get all these young people to participate in a study and it turns out they all got a 35 quid, Amazon, or iTunes voucher as compensation.

[00:13:00] David: [00:13:00] Yeah.

[00:13:01]Sophie: [00:13:01] which I think is good. And, uh, Yeah.

[00:13:02] So what they did, and this is where it gets a bit complicated for me, Dave, and you can just jump in there when you feel the need, but everyone in this study completed two separate sessions. So one of them was an imaging session where they literally image the brain.

[00:13:17] And then the other one was a mathematical assessment session where they actually got them to do sort of math tasks and problem solving things. And they also talked to them about math, anxiety and other stuff.   I’ll let you get into the brain stuff in a second, but when they were doing the imaging or they had structure imaging and MRS acquisition, they just got the participants to watch the Lego movie, and I just like image their brain while they were watching the Lego movie. And then during the resting F MRI participants were asked to fixate on a white cross on a black background.

[00:13:47] David: [00:13:47] So do we know that this is the effect of mathematics and not the effect of believing or not disbelieving the statement that everything is awesome.

[00:13:55] Sophie: [00:13:55] Yeah. Well, exactly. It’s a very good question, but, um, yeah. Dave, do you have any idea how any of that imaging worked or not really, because It was a bit much for me

[00:14:02]David: [00:14:02] it started off fine. And then it got very complicated. So it was an MRI study. So MRI is Magnetic Resonance Imaging. And this is where you apply a very, very strong magnetic field to the brain in an imaging device. And somehow it aligns all of the hydrogen molecules in your brain. And that allows you to  make a picture of it.

[00:14:21] And I kind of understand that I kind of superficially understand that, but they’ve done something even more complicated. They’ve done what’s called magnetic resonance spectroscopy

[00:14:29]Sophie: [00:14:29] Yes.

[00:14:30]David: [00:14:30] And somehow this allows you from that signal that comes out of the brain when you apply that magnetic field to quantify the relative amount of a particular organic molecule, like a neuro-transmitter.

[00:14:45] And there’s like a list of, if you look up the technique, there’s a list of them that you can do. And they’re mostly neuro-transmitters cause that’s what you’d be interested in the brain. I don’t understand how it works, Sophie.

[00:14:55] Sophie: [00:14:55] Okay, good. Cause I had no idea.

[00:14:57]David: [00:14:57] So I know that chemists use nuclear magnetic resonance spectroscopy, and, but that would be like something static.

[00:15:03] It would be like a chemical in a solution. And you better apply the magnetic field to that. It wouldn’t be something complicated, like a brain. So from what I can tell from the methods, what they did was they applied the strong magnetic field to the brain, and then they compared it to known samples and then did some jiggery pokery with models and compared it to an ideal brain and did some fancy modeling basically that enabled them to make these relative distinctions.

[00:15:27] But it’s really, really complicated and I probably misrepresented how it works.

[00:15:31]Sophie: [00:15:31] Well, look, I mean, you did, you had a fair whack at it and it was far better than mine, but Yeah. Interesting thing that they found was that students who didn’t study maths had lower amounts of a crucial chemical for brain plasticity, which I’m going to say. And then you can tell me how to say it. So it’s a gamma amino butyric acid or GABA.

[00:15:51]Which I’m going to say GABA from now on

[00:15:52] David: [00:15:52] and

[00:15:53] Sophie: [00:15:53] as you said, it was a neurotransmitter. And from what I can tell, it’s kind of like the brains calming agent. So it reduces neuronal excitability throughout the nervous system. Is that true Dave?

[00:16:01] day,

[00:16:02] David: [00:16:02] Yeah. So very, very, very broadly, glutamate is the main excitatory neurotransmitter. So it switches neurons on and GABA is the main inhibitor in your transmitter. So it switches neurons off. There’s lots of them that do lots of things, and some of them have strong effects and weak effects and modulator effects.

[00:16:17] But GABA and glutamate are the kind of two big ones, the big on and off.

[00:16:22] Sophie: [00:16:22] Yeah and what they found was that there were lower amounts of GABA in the key brain region involved in many of these important cognitive functions, including reasoning and problem solving and maths and memory and learning. So they could basically discriminate between those who studied math and those who didn’t based on the amount of GABA found in their brains.

[00:16:43] And this is irrelevant of those cognitive ability studies. So it’s like they, even, if you ignore the cognitive ability study and look at the amount of GABA, you could actually say these students are taking A-level maths and these students and not taking A level math.

[00:16:57] David: [00:16:57] That’s right. And when you looked at the probability, there was a probability curve relationship and it was just like almost perfectly matched. It was beautiful between the predicted score and the gap of concentration. Um, so it was a really, really powerful effect and they did some FMRI stuff as well.

[00:17:14] So that’s functional magnetic resonance imaging. This is where you used the same bit of kit to determine changes in local blood flow, because what tends, what happens in the brain is that when one region of the brain is activated, you tend to get more blood flowing there to enable the neurons to work harder.

[00:17:30] And then when they did the FMRI they found more activity in various regions and they found evidence of functional connectivity between regions, which is basically where the regions switch on together, which means they’re working together and that was associated with increased, outcomes in the cognitive tests.

[00:17:46] Sophie: [00:17:46] Yeah. and then apparently there were other findings, like, so these  the differences in the GABA levels were not present when deciding to cease maths education. So the idea is everyone started off the same and then people made this decision to keep doing maths or not do maths. And that’s when you see the change, it wasn’t like these people already had lower or higher levels of GABA.

[00:18:09] And then somehow that became part of the decision-making. And then also they could predict things. As you said, predict future mathematical reasoning when the sample was reassessed, like 19 months later.

[00:18:20] David: [00:18:20] Yeah, that’s right. So the, amount of GABA and the middle frontal gyrus, which is what they were looking at.

[00:18:25] Sophie: [00:18:25] Yeah.

[00:18:26]David: [00:18:26] It predicted changes in mathematical reasoning 19 months later. So they could also predict just by looking at the brains of these people, whether or not that would have an influence on their mathematical reasoning after quite a lot of time when they’d left school, presumably

[00:18:39] Sophie: [00:18:39] Yeah. so it’s really interesting. So I’ll let you know. I always tell people that I need to do math, but I mean, this is kind of like a bit more of a quantitative concrete reason why you need to keep doing maths or you’re not going to have enough GABA guys.

[00:18:53]David: [00:18:53] Yeah, that’s right. You’re not gonna have enough GABA. they raised it an interesting point, which was that maybe this means that if people are going to stop, it’s fine if people want to stop studying maths, but maybe if they’re going to stop studying maths, we should introduce some other kind of non math material that induces the same kind of reasoning and logic processes.

[00:19:09] because this kind of mathematical training seems to be beneficial to your reasoning and problem solving in general, maybe we should do something to give people who don’t study maths who maybe hate maths, who experienced maths anxiety and are never going to do it, bless their hearts.

[00:19:24]Um, something else that will encourage that kind of cognitive development.

[00:19:27] Sophie: [00:19:27] Yeah. And now I sort of feel good that when I’ve been telling people all this time, that by doing maths, you learn all these other skills, like critical and analytical thinking and problem solving and reasoning. I haven’t actually been lying just to make them do  maths. there’s some skerrick of truth in my rhetoric

[00:19:41] David: [00:19:41] print out this paper and bind it into a book and then throw the book at them.

[00:19:45] Sophie: [00:19:45] Yeah. So every maths teacher out there, we now have evidence, but yeah, I think It’s true because there are some people that just, you know, for various reasons, they don’t like math and they don’t want to do maths.  it starts off with maybe some bad experiences or something else. But I think forcing people to do something they don’t want is actually quite counterproductive.

[00:20:03] David: [00:20:03] Okay.

[00:20:03] Sophie: [00:20:03] And so if you’re coming up with something that they can do instead, that means that they’re still sort of still developing in the way that the maths kids are, think is really good. So, um, yeah, like really interesting. And they go over and you have to do maths or you won’t have enough GABA.

[00:20:18]Kirigami Drug Delivery [00:20:18]

[00:20:18]  From the art of maths to the art of, folding and cutting paper to put in your arteries, Dave.

[00:20:36]David: [00:20:36] Yes this week, we’re talking about stents inspired by paper cutting art as a means of treating any tubular organ.

[00:20:43]Sophie: [00:20:43] Yeah. we’re not actually talking about arteries first off. I really want to talk to about the gastrointestinal tract,

[00:20:48]  but, Yeah. so this is some stuff that’s come out of MIT and it’s inspired by kirigami which is the Japanese art of folding and cutting paper. so kiri and gami literally translate as to cut  paper. Um,

[00:21:01] David: [00:21:01] Yes

[00:21:01] Sophie: [00:21:01] And the idea is this is for people who have, um, inflammatory diseases that affect the gastrointestinal tract, like eosinophilic esophogitis et al.  and Yeah and the idea is, you know, normally to treat these kinds of, uh, diseases, you would basically be taking drugs that dampen the body’s immune response.

[00:21:21]But that also means that it affects the entire body, right? So if you have injection

[00:21:24] David: [00:21:24] Yeah.

[00:21:24] Sophie: [00:21:24] or you take a pill or you do something, it’s affecting the entire body and these stents offer a way to deliver drugs in sort of a targeted way. So you can find the portion of the digestive tract in this case, and you can inject it with the drugs. And so the digestive tract is quite interesting, Dave, because it really needs to remain fairly open. So

[00:21:43] David: [00:21:43] Yes.

[00:21:44] Sophie: [00:21:44] a bowel obstruction or something.

[00:21:46] David: [00:21:46] Yeah.

[00:21:47] Sophie: [00:21:47] the idea is with these Very very cool stents, I really enjoyed reading this paper. The idea is these shapes can go from flat to 3d to what they’re described as buckled out, which is when sort of the little needles pop out and, you know, for tissue engagement.

[00:22:01] And then they can go back to being flat so you can remove them again.

[00:22:04]David: [00:22:04] Yeah, that’s right. so you, mentioned that, uh, treating with a drug as systemically. So treating like with, something you swallow or something, you inject treats everything so that you get side effects and yeah. So we’ve had stent technology for a long time. Um, cause we use them in arteries to like pop open coronary arteries that are closed.

[00:22:21] And they’re basically just like a, it’s a tube made of metal mesh. But the problem with putting them in the gut is that it’s very, very difficult to get them in there. And once they’re in there, they tend to do something called migrate, which is as they move around and do stuff and it’s not great. And also.

[00:22:37]What we want to do is deliver drugs. It’s not ideal to put it in there and leave it in there because it will only deliver drugs for so long. So, once it’s in there, it’s hard to get it out. So what’s great about these is that they go in smooth, and then when you stretch them, they pop up these like little side panels are courted in drug releasing nanoparticles, and then when you want to take it out again, you just unstretch, it. Pull out with an endoscope and Bob’s your bloody mother’s brother.

[00:23:06]Sophie: [00:23:06] It’s amazing. Yeah. So basically they, as you said, so I don’t know. I’ve heard to try and visualize this at home, the stent is made of sort of two key elements. So you’ve got the soft, stretchy tube that’s made of a Silicon based rubber. I would describe it as like a criss cross helical threads.

[00:23:19] So imagine if you got like a helix and now helix and the other direction and cross them, that’s sort of what it looked like and the idea so that’s your rubber tube. then there’s a plastic coating on that, which is laser etched. And so the idea is that when you stretch the rubber tube, it pushes this sort of these etched things out. It looks a bit like a Palm tree. I think that’s the way like a Palm tree trunk.

[00:23:40] David: [00:23:40] Yeah.

[00:23:40] Sophie: [00:23:40] That’s what it look like the most maybe. And the idea is, I would say you’ve got your Palm tree and your stretch your Palm tree, the kind of weird frondy bark like sticks out. And that’s got the little plastic needles that you can inject the nano-particles from.

[00:23:52] And as you said, they stick it  inside. You inflated tube, which causes this thing to stretch. It basically releases the drugs. And then yet you just, uninflate the balloon and then pull it out when you’re done. And of course, that’s nice. So they did some real experiments on pigs and there’s poor pigs, always on the pigs, but also they did some very cute finite element simulations, which I loved

[00:24:12]  David: [00:24:13] well, what’s the finite element simulation.

[00:24:15] Sophie: [00:24:15] Basically, it’s just a computer simulation where you sort of make up your domain using a bunch of finite elements. So essentially you take like a shape and you turn it into like lots of small shapes and

[00:24:24] David: [00:24:24] Okay.

[00:24:25] Sophie: [00:24:25] kind of control it. And, um, the reason they did that was because if you think there’s like a lot of different they could do here.

[00:24:31] So there was like the size of the needle, the thickness of the shell, or surface, like the pressure.  Actuate a pressure that we’re using to inflate the balloon.  I mean, that would be quite costly and time consuming do all of those experiments separately. So the idea is they could create this finite element model and then they could do all those kinds of tests to look at the variations.

[00:24:50] And then they also tested the stents in the esophagus of a pig. So they actually had three Yorkshire pigs, and 30 minutes after they euthanized the pigs, I’m always interested in animals, in science, Dave. So apparently they euthanized them, and then they injected them with sodium pentobarbital

[00:25:06]and they killed them. And then 30 minutes later, They tried  these stents out and apparently it works very, very well.

[00:25:13]David: [00:25:13] There you go. And they say the technology could be applied to any tubular organ. I initially thought this meant an organ that was radical or indeed far out, But in fact it means any kind of tube shaped organ and so this would include not just like the gastrointestinal tract and the esophagus, but also like the respiratory system, anywhere in the body where you’ve got like a tube shaped thing that you’d want to put something into, we’re getting into dangerous territory. Now you could use one of these stents

[00:25:40] Sophie: [00:25:40] You said that you’d want to put something into, so I don’t know if that helps.

[00:25:43] David: [00:25:43] Yes, therapeutically.

[00:25:46] Sophie: [00:25:46] Yeah.

[00:25:46] David: [00:25:46] I also thought it was interesting. The design was inspired by kirigami as described, a technique that traversals lab had previously used to design a non-slip coating for shoe soles. So we seem to be operating fairly opportunistically here in terms of what problems we’re going after to go from non-slip shoe soles to let’s just cure inflammatory bowel disease.

[00:26:10] Sophie: [00:26:10] using kirigami stents with micro particle drugs on the needle ends.

[00:26:15] I’d be quite interested to see what the next thing to come out of this group is what are we going to use like plastic kirigami for, but Yeah, like the,

[00:26:22] David: [00:26:22] yeah,

[00:26:22] Sophie: [00:26:22] the design restrict the cool. I, like, W what happened to those shoe soles, dave? Why were they so magical? Where are they? Why are they not on our shoe?

[00:26:30] David: [00:26:30] I don’t know that. I just know that it happened and I found it funny.

[00:26:33]Sophie: [00:26:33] it was quite a funny.

[00:26:34]but yeah, there you go. So it was, yeah, it worked well, in the pig. they did some nice simulations. Um, and it also looks really cool. as I said it looked like a fun little futuristic Palm tree without any leaves injecting drugs into your gut.

[00:26:47] David: [00:26:47] yeah, they say a stretchable, snakeskin inspired kirigami shell integrated with a fluidic lead driven, linear soft actuator, which I just like saying that. That’s just some top drawer technobabble

[00:26:58] Sophie: [00:26:58] I really like to get that on a t-shirt maybe I don’t often wear t-shirts with words on them a lot, but I feel like that just like maybe in quite small font, just somewhere randomly on the t-shirt would be cute. So if anyone’s interested in that, let us know and we’ll start making some  STEMology merch with just that phrase to start off with maybe some tote bags.

[00:27:15]  Blue Eye Ancestor [00:27:25] From your guts, Dave, to your eyeballs.

[00:27:29] David: [00:27:29] Yep. it’s not far. And yet far enough really? Isn’t it.

[00:27:33] Sophie: [00:27:33] That’s right. So, This paper apart from being one of the most traumatizing things to try and read as someone who knows nothing about genes, it actually blew my mind. So Dave University of Copenhagen has just told us that people with blue eyes have a single common ancestor. Every single person in the world with blue eyes is a descendant of one person in the past who had a mutant gene where they couldn’t produce enough melanin in their eyes. They got blue eyes. And now we have all these people with blue eyes and then variations.

[00:28:07]David: [00:28:07] Yes.

[00:28:08] Sophie: [00:28:08] Oh my gosh,

[00:28:09] David: [00:28:09] Yes. It’s a bit mad. So the way that blue eyes seems to come about is through a gene mutation on a gene called OCA two, which  is

[00:28:18]Sophie: [00:28:18] it makes the pea protein.

[00:28:20] David: [00:28:20] makes the pea protein and, but it’s OCA is oculocutaneous albinism genes. So basically if, all of these genes are deleted or mutated, then you have albinism, which is

[00:28:31] Sophie: [00:28:31] Yeah.

[00:28:31] David: [00:28:31] white hair and white skin. And.

[00:28:33]Sophie: [00:28:33] like a total lack of pigment,

[00:28:35] David: [00:28:35] Yeah, that’s a total lack of pigment. So if you have a little selective mutation to OCA too, it seems like that turns off just enough melanin in just the right spot that your eyes go blue, but you don’t have any of the other, um, sorts of signs.

[00:28:50] Sophie: [00:28:50] Yep. And so, yeah, so my understanding is it’s basically, yeah, this genetic mutation affects OCA two gene, and it sort of creates this switch and what the switch does it effectively sort of dilutes the brown eyes to blue, but then what I didn’t realize Dave is that like green eyes and Hazel eyes and a lot of other eyes.

[00:29:10] They’re not unique colors. They’re basically somewhere in this spectrum between blue and brown. So It turns out there are four different types of eyes that fall in this regime. So you’ve got blue, which is just totally blue, no brown in your blue. At the other end of the spectrum from blue to brown is funnily enough brown, which

[00:29:28] David: [00:29:28] brown

[00:29:28] Sophie: [00:29:28] total brown pigmentation. I believe I have that I think maybe you have that as well,

[00:29:32] David: [00:29:32] I have that too.

[00:29:33]Sophie: [00:29:33] And then you’ve got blue with brown spots, then you’ve also got your brown green slash Hazel, which is kind of the blue with brown spots, but with some more brown and they had these pictures and I was like, Yeah. that’s true. Like when you look at Hazel eyes and you look at sort of what sort of you think a kind of green eyes, it’s really just a weird mixture of The blue and the brown.

[00:29:54]And it all came from one person. And yes they examined some mitochondrial DNA from a bunch of people.

[00:30:01] So, as I said, they started off in Denmark.

[00:30:03] David: [00:30:03] Yeah.

[00:30:03] Sophie: [00:30:03] they had, um, families where at least one individual had brown eyes and 55 families were all individual had blue eyes and they weren’t interested in like green in that spectrum.

[00:30:13] So they got rid of those families. they had additional control material for DNA sequencing from two other large Danish families, I think. And then they had five individuals from Turkey with blue eyes, black hair and light skin, two individuals from Jordan with blue eyes, black hair and dark skin. And then they also had two people with natal heterochromatin.

[00:30:34] So that’s where you either get variation of color in one eye or two different colored eyes, which is the thing that, so don’t know if you’re a big goosebumps fan. This is

[00:30:43] David: [00:30:43] back in the

[00:30:44] Sophie: [00:30:44] sense. Yeah.

[00:30:45] yeah. So there is, I don’t know if you remember one of the books it’s called my hairiest adventure about these kids. They put this like fake tan on, and then they start like developing skin, weed, hairy skin. And then they turn into dogs and spoiler alert,  it turns out that they were actually dogs to start off with. And their parents had been part of some weird thing that turned them into people. Anyway, one of the characters, Lily had a green eye and a blue eye.

[00:31:06] I remember, and then the reason like this is important is because when she turns into a dog, you know, like,

[00:31:10] The dog,

[00:31:11] David: [00:31:11] yeah. Yeah.

[00:31:12] Sophie: [00:31:12] Um, but I remember going, like, I want that. And I remember being quite annoyed that I didn’t have like a brown eyes, blue eyes, or like a brown eyes and a green eye and I did blame my parents a little bit for that anyway. they examined the DNA of all of these painful Dave and the conclusion was all blue-eyed individuals are linked to the same ancestor and everyone inherited the same switch at exactly the same spot in their DNA.

[00:31:38] David: [00:31:38] Yes.

[00:31:38] Sophie: [00:31:38] sort of true?

[00:31:39]David: [00:31:39] That’s sort of what I understood was that because the amount of variation in the blue of the blue eye is so small in people who have pure blue eyes they basically  they say, it’s a highly conserved sequence. So they kind of infer that because it’s so specific and the amount of melonan produced is so similar, it’s probably all came from the same person rather than the alternative to that would be having little mutations at various places on the gene that break it or stop it from working in different places, but all produce kind of a similar effect and they call that convergent evolution.

[00:32:18] So for example, the eye and the ability to fly don’t have common ancestors, like things with eyes. The eye has evolved multiple different times. They’re multiple different streams. so this is not that this is basically the opposite of that. there’s one common ancestor with one sort of mutation that seems to have been propagated through all blue eyed people. And they conclude, they call it the Founder Mutation, which was cool.

[00:32:43]That was my understanding of what happened. I also really enjoyed. So you talked about the families, the family used, they used linkage analysis association and haplotype studies of Danish origin. And these were retrieved from the Copenhagen family bank,

[00:32:58]Sophie: [00:32:58] Yeah.

[00:32:59]David: [00:32:59] the Copenhagen family bank, which is not like a little community bank in a little town.

[00:33:04]It’s a family bank. It’s a bank of families. It’s a bank of like genetic information.

[00:33:11] Sophie: [00:33:11] Okay. So not just actually just like a bank where they take a bunch of families and they imprison them in the bank and that’s where they live and die.

[00:33:17] David: [00:33:17] No, that would be weird. That would be a bank that we’ve always dreamed of making a deposit into. Um, I think, but no, that’s not what it is. It’s a bank of genetic information and that’s where they got their data, which I think is fun that somebody set that up in Copenhagen.

[00:33:30]Sophie: [00:33:30] Good on you Copenhagen. But yeah. And the other thing that I found quite interesting about this, so apparently um, these findings, are the latest in a decade of genetic research beginning in 96, where they in 96 was when they first implicated the OCA two gene as being responsible for, you know, this kind of eye colour stuff.

[00:33:46] Then there was talk about positive and negative mutation. And how sort of humans are one of these things where we have these mutations in our past, where it actually has nothing to do with survival or anything else it’s not, you know, having blue eyes or brown eyes is neither positive nor negative. And then that’s the same thing as like hair color and baldness, or having like freckles or beauty spots.

[00:34:06] But, and I’d never really thought about the fact that have done all this, you know, if you think about like evolution and nature and mutations, and there’s a mutation that makes someone like a better predator. And then it turns out that then that’s the mutation that sort of ends up surviving because like the rest of the things die out. But we’ve got all these dumb things that the body has done just to make us like a little bit different. But for there is no, um, I dunno for no reason, but in like a charming way.

[00:34:28]David: [00:34:28] Yeah, it’s really interesting. And then it gets into kind of, um, if it’s just things that make us more or less attractive to other members of members of the opposite sex that are going to produce children,

[00:34:36]Sophie: [00:34:36] yeah. there you go. So I know that as, as you could probably tell from my excitement, like this really just kind of blew my mind a bit, the fact that everyone with blue or bluish eyes, they share a common ancestor. So like one person in the past, slight mutant, and now we’ve got blue eyes.