Shamini Bundell
Welcome back to the Nature Podcast, this time: a useful quantum computer...
Nick Petrić Howe
...and how the therapeutic effect of psychedelics might work. I'm Nick Petrić Howe.
Shamini Bundell
And I'm Shamini Bundell.
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Shamini Bundell
First up on the show, Nick, you've been looking into quantum computers.
Nick Petrić Howe
Yeah, that's right. This week in Nature, there's a paper from IBM that claims to show a practical use for quantum computers. Now, you might remember that whilst there's been various claims of quantum advantage, quantum computers being better than classical computers, there's not been a huge amount of applications of the technology, but that might be about to change. To find out more, I caught with Nature's Davide Castelvecchi, who's been writing a news article about this paper. Davide, hi, how's it going?
Davide Castelvecchi
Hi, very good. Thanks for having me.
Nick Petrić Howe
Well, it's great to have you here too, Davide. And so just to get us started, I wondered if we could do just a little bit of a recap, what is the difference between a quantum computer and a more classical computer people might be familiar with?
Davide Castelvecchi
A quantum computer is very different than that it stores information in quantum states, which you know, compared to classical computers, which have bits that can be zero or one, quantum states can be any kind of strange superposition of a zero and a one. So, they can be a little bit of a zero and a little bit of one. And it's only when you measure them that they end up giving you one answer or the other. So that's one thing they have qubits, they're called, instead of bits. And the calculations that you do are essentially physics experiments where you put qubits in some kind of collective quantum states, you have a number of qubits, and you can entangle them so that they are all correlated, and so on. And then you perform a measurement. And the measurement gives you information about the thing you want to calculate.
Nick Petrić Howe
And so this week in Nature, there's a paper that is demonstrating what they think is kind of a useful application of a quantum computer. Can you tell me what it was they were doing with this quantum computer and what kind of quantum computer it was?
Davide Castelvecchi
Now the quantum computer they use this chip has 127 qubits, which — at the time when IBM unveiled it — was a record, in 2021. They have since gotten to 433, as of last year, and they are expected this year to get past 1000, for the first time. And what they did, I mean, the experiment they did in this paper is basically they calculated properties of some kind of abstract two-dimensional magnetic material. The specific experiment they did doesn't tell us anything new about magnetism, or materials, or physics in general. But what they feel is that it's an important, basically milestone, showing that this quantum computer has reached a level of sophistication, they have reached the level of know-how to get useful applications out of it at some point soon. So, they're talking about within the next two years.
Nick Petrić Howe
And why was this particular to the material state? Was this something that the quantum computer was particularly able to work well with?
Davide Castelvecchi
What they did is they simulated basically an array of bar magnets. So imagine the needle of compass, and needles of a compass, if you put two of them next to each other, they're going to feel each other, they're going to try to align or in one way or another. And when you have many of them together, the arrangements in which they tend to fall into can be very complex and very, very unpredictable. Now, what I described with needles of compasses is a classical picture. But what they've done actually is a quantum version where each needle can point up or down, or simultaneous up or down in some kind of complex combination of the two. Because these qubits are quantum objects and you can make them interact basically with the same rules, that the atoms in the material would interact, the quantum computer solves the physics for you. And that's why people are optimistic that you know, physics problems, such as this one will be a very good fit, you know, test case or use case scenario where quantum computers can show that they're actually useful.
Nick Petrić Howe
And to what degree was this quantum computer better, or more able, to tackle this problem compared to a conventional one?
Davide Castelvecchi
Yeah. So what IBM told me is, they don't claim that they've done something that is beyond classical computers at this stage. What they say is that they've reached a regime where classical computers struggle to keep up. And this is with the 127-qubit machine. So they expect that in a couple of years, when they start doing this kind of thing with the with more than 1000 qubits, there will be a stage where there clearly is an advantage. And where you can solve specific questions that can be in chemistry, or material science, or even maybe optimization theory, that would be very hard to solve otherwise.
Nick Petrić Howe
Now, as I understand it, one problem that's really plagued quantum computers is errors. And one idea has been to use more qubits to error correct, correct these errors, but you'd need many, many more qubits than that were present here. So how did they deal with the errors in this case?
Davide Castelvecchi
Yeah, so the perhaps the the most intriguing aspect of this paper is that they're claiming something that until very recently, was considered impractical or impossible, because they're taking a different strategy. So, the long term strategy for quantum computing is that you — like you were saying — you will need a lot of qubits in a kind of ancillary role to just provide error correction to keep the error rate down. So that's a long-term strategy. But what IBM is saying is, we're not trying to do error correction here, we're trying to have a more modest target, which is not to remove the errors, but to lower them. They call it error mitigation. So that's what they do here. And that's what they say, should be able to produce useful results, even with 1000 qubits. If you wanted to do something useful, with a fully error corrected quantum computer, people are talking about maybe you'll need a million qubits.
Nick Petrić Howe
And so from what you've described, it sounds like this would be quite a difficult technical challenge to deal with errors with only 127 qubits. How did they sort of manage it?
Davide Castelvecchi
So, a lot of it is just steady technical improvements. And, in particular, one metric here of the technology is that the individual qubit can stay in a quantum state for a longer time than before. And this allows you, when you start doing calculations, you start putting them into these quantum states, it means that they will stay in there for a longer time. And in fact, you can do longer operations to put them in a more and more complex quantum state, which you wouldn't be able to do otherwise; if you know as soon as you put a qubit in a state, it loses the information within a microsecond, then you'll never be able to get to the stage of you know, simulating a two-dimensional magnet.
Nick Petrić Howe
And you've been talking to a lot of different researchers in the field, what is the sense you're getting from them about what this particular paper means?
Davide Castelvecchi
So the researchers I spoke with, they told me that the claims that IBM is making are kind of brave, considering that until not long ago, the usefulness of a quantum computer was seen to be something in the distant future, but also that they are backed up by solid evidence, and also that they're making claims that are substantial, but not completely outside of the realm of possibility.
Nick Petrić Howe
And, you know, while we've been saying that this is a potentially useful application of it, is this something that could actually be used right now? Could it be used by industrial applications or whatever to try and figure specific problems out?
Davide Castelvecchi
Yes. And there's a number of commercial entities that are already discussing this with IBM, whether they will actually get value out of it remains to be seen. But there's also physicists who are starting to use quantum computers to answer basic science questions. For example, you could start calculating properties of neutrinos, how neutrinos interact with one another inside the supernova explosion, which are things that I am told are beyond the standard techniques, but it's one of the things where even a small quantum computer could start giving answers.
Nick Petrić Howe
So, I guess I'll probably be talking to you again in the future, Davide, about what's next for quantum computing, because I don't think this is the end of the story. But for now, thank you so much for joining me.
Davide Castelvecchi
Always a pleasure, Nick.
Nick Petrić Howe
That was Nature's Davide Castelvecchi. To find out more about this story, we'll put links to the paper and Davide's news article in the show notes.
Shamini Bundell
Coming up, exactly how psychedelic drugs work is a bit of a mystery, but now researchers may have found a key piece of the puzzle. Right now though, it's time for the research highlights with Dan Fox.
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Dan Fox
Some disease-causing bacteria congregate inside thick biofilms that shield the microbes from host immune cells. Now, researchers have found that Vibrio cholerae, the bacterium that causes cholera, has turned these defensive biofilms into a potent weapon. The team grew a variety of human immune cells in the presence of Vibrio cholerae. They found that the bacteria quickly divided and encased the immune cells in biofilms, killing them within a matter of hours. Further experiments showed that the biofilms helped the bacteria to concentrate high levels of a toxin onto the surface of immune cells, called macrophages, punching holes in the target cells protective membranes. The researchers say it's not yet clear whether the bacterium uses these biofilms during actual cholera infections, but they could explain why people who have recovered from cholera harbor antibodies against a key biofilm component. You can encase yourself in that research over at Cell.
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Dan Fox
The Arctic Ocean will lose all summer sea ice in the coming decades, even if drastic cuts are made to carbon emissions. Floating sea ice on the Arctic Ocean has been shrinking and thinning in recent decades, as temperatures rise in the Arctic region. And so researchers have been trying to forecast how soon the Arctic will be ice free at the end of the summer. To investigate the human impact on the Arctic ice researchers analyzed three sets of satellite observations including data from 1979 to 2019. The team compared the observation with climate simulations that incorporate human influences such as the amount of greenhouse gases and other climate altering substances that are entering the atmosphere. The observations showed that human activity is already having an impact on Arctic sea ice, and the simulations predict the Arctic could be ice free at the end of summer in even the lowest emission scenarios, something that could occur as early as 2030. You can find that research in Nature Communications.
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Shamini Bundell
Next up on the show, understanding how psychedelic drugs work.
Nick Petrić Howe
Psychedelics are a range of drugs that can be roughly grouped together by their ability to cause an altered state of consciousness. For example, MDMA is a psychedelic along with things like ketamine, LSD, Ibogaine, and psilocybin. Now these compounds are probably mostly thought of as illicit substances, but there's an increasing interest in them for their therapeutic potential in conditions such as depression, post-traumatic stress disorder, and even addiction. However, there's still a lot we don't know about psychedelics. To start, they don't all bind to the same receptors in the brain. But despite this, when used as therapeutics, they seem to work in a similar way. One idea to explain this is that psychedelics may be reopening something known as a critical period, a time when the brain is particularly malleable and able to make new connections. For example, it's one naturally occurring critical period that makes it easier for children to learn new languages. In fact, a few years ago, a mice study in Nature showed that MDMA does indeed open a particular critical period, known as the social critical period, where organisms are particularly attuned to social situations.
Gül Dölen
So the example I tend to use is, you know, when I was a teenager, you really had to pay attention to what your peers liked and didn't like so that you could make sure to get the exact right shade of acid-washed jeans, right?
Nick Petrić Howe
This is author of that mouse paper, Gül Dölen, a neuroscientist from Johns Hopkins.
Gül Dölen
And so, this sensitivity to learning from your social environment probably is encoding things like how we fit in, social hierarchy, the rules of our social world.
Nick Petrić Howe
Now, if this is all sounding a bit familiar, is because back in 2019, Gül was on the podcast talking about that paper. But how MDMA had this effect on the social critical periods, still wasn't clear. Gül and the team had thought it had something to do with the mice be more attuned to social conditions, as MDMA is well-known to enhance how social people are. But looking into this more in a new paper in Nature, that doesn't seem to be the case.
Gül Dölen
So, at the beginning of the current paper, we were really pretty surprised to find out that actually, if we gave any psychedelic so — whether or not it has a pro-social profile. It's not that LSD or Ibogaine, or ketamine are particularly pro-social as psychedelics, but all of them are able to reopen this critical period.
Nick Petrić Howe
If these drugs are all reopening critical periods, it could explain why they all have similar therapeutic effects. But then this raised a new question: how are they all doing the same thing, despite not binding to the same receptors in the brain?
Gül Dölen
These effects are lasting for a really long time, well beyond what you would expect just to be encoded by changes at the receptor. And so given that, you know, the psychedelic effects were lasting 48 hours to four weeks after we thought, well, maybe something is happening, that is going to be encoded at the level of regulating the DNA transcription.
Nick Petrić Howe
Gül and the team identified a list of 65 genes that seem to be involved, when this critical period was open in mice. Of those around 20% seem to be involved in regulating something known as the extracellular matrix.
Gül Dölen
I like to think of it as sort of the grout between the tiles — I mean, my friends who study extracellular matrix in a more serious manner, are gonna hate that analogy — but just, you know, for simplicity’s sake you know it sort of stabilizes those synapses, and it kind of locks everything into place. So that, you know, if you make a memory... Let's say, you know, Gül and Nick met today, that memory gets stabilized and sort of locked into place because that extracellular matrix is sort of the last step of that. So the idea is, is that if you want to enable, you know, cognitive flexibility, if you want to enable rewriting of memories, or reconfiguring of habits or patterns of behavior, then degrading that extracellular matrix could be thought of as the first necessary step to get that loosening up so that you can change the memories and the synaptic architecture.
Nick Petrić Howe
This increased malleability of the brain structures could be what's behind the brain's ability to absorb more information and be more flexible during those critical periods. This could also help us understand how to use psychedelics in treating things like depression and PTSD. As Alex Kwan, neuroscientist from Cornell University, explains.
Alex Kwan
So I think this speaks to the fact that a lot of psychedelics... they're not given like your normal medication, when you go home and take a pill, right, they're given in the presence of other medical professional, and then often sometimes, particularly for things like MDMA, assisted psychotherapy. So they're actually therapy going on while you're doing these substances. The implication is, maybe you take advantage of some of these processes, but you're also guiding the person and actually doing therapy at the same time. So that component could be quite important. According to the conclusion of this paper.
Nick Petrić Howe
Gül agrees that the psychedelics are best used in conjunction with targeted therapies, you can't necessarily expect to see the therapeutic effects without both. The paper also suggests that the actual psychedelic effects of these drugs are important for the reopening of the critical period. This could be important as there are ongoing efforts to try and remove these effects from the drugs to try and take advantage of the therapeutic potential without the altered states of consciousness.
Alex Kwan
And if you get rid of it, then maybe these compounds would no longer be useful for treating mental illnesses. But that I think, remains to be tested and determined.
Nick Petrić Howe
This study is in mice, and there's a lot more that remains to be figured out about psychedelics. But for Gül this work may open up the array of diseases that they could potentially treat. By making the brain just a little bit more malleable.
Gül Dölen
I think it's a pretty radically different way of framing how it is that psychedelics are having their therapeutic effects. And you know, I think opens up the landscape of what diseases we might be able to use this intervention to treat, right? So right now, mostly we're focused on neuropsychiatric diseases with psychedelics. So most of the clinical trials are focused on antidepressant activities, PTSD, addiction, those are the three big ones that people are trying to use psychedelics to treat, and this explanation suggests that, well, we can really probably widen that out quite a bit. And now we might be able to think about how we would use psychedelics as an adjunct therapy for a lot of different diseases, including, you know, the... stroke, deafness, blindness, you know, so it really changes the landscape and makes many more diseases, possibly ones that we could treat with psychedelics.
Nick Petrić Howe
That was Gül Dölen from Johns Hopkins in the US. You also heard from Alex Kwan from Cornell University, also in the US. To find out more about this research, check out the show notes for some links.
Shamini Bundell
Finally on the show, it's time for the briefing chat. So Nick, what have you found for us this week?
Nick Petrić Howe
Well, this week, I've been reading an article in Nature about something called taurine, and its effect on the lifespan of animals.
Shamini Bundell
Okay, now taurine... Sounds familiar, sounds like one of those biological chemicals that I should definitely remember what it does. What's what's taurine about?
Nick Petrić Howe
So, taurine is an amino acid. And as you know—
Shamini Bundell
—that's the one—
Nick Petrić Howe
—amino acids are the building blocks of proteins. And taurine is also well known as an additive for energy drinks. So—
Shamini Bundell
—oh—
Nick Petrić Howe
—it's quite well known, but aside from its sort of use in energy drinks, as animals age, they have less taurine in their systems. And so this study has been trying to see what would happen if you gave ageing animals more taurine.
Shamini Bundell
Oh okay, so what was the kind of study set up?
Nick Petrić Howe
So, there was a couple of different things they did in this study. So, they looked at a few different kinds of animals. So they looked at mice, they looked at rhesus monkeys, and they looked at C. elegans, so little worm type thing. And they basically, were seeing what would happen if the more elderly animals had a high dose of taurine. And they found that basically, it seemed to extend the lifespan — by a significant degree — of the different animals. And it also seemed to largely make them healthier too.
Shamini Bundell
Is there any understanding of a possible mechanism?
Nick Petrić Howe
That is still not clear, like exactly how it works is something that still needs to be sort of uncovered. And what we do know about taurine is that at the cellular level, it is sort of a protector of cells, and it promotes the survival of individual cells. So possibly, it's doing something to sort of make the cells better able to last longer. But for example, in the mice, when they were given the taurine, they had better muscle endurance and strength. And in female mice, they had less depression and anxiety-associated behaviors, and their immunity was better. So, it seems like there's a range of different things that have been affected by taurine. But exactly how that works is still kind of unclear.
Shamini Bundell
But the overall finding of this paper, I can imagine that you know that there must be a lot of headlines, you know about this being a magical silver bullet that's going to cure all ageing, does the does this sort of paper back that up or go go in that direction?
Nick Petrić Howe
So, this is in some animals, it's not in humans, humans are quite different. And some of the researchers interviewed for this article caution that ageing is a very multifaceted process. Like there's a lot of different things going on, when we age is not going to be just one thing that's going to solve everything. There’re rarely magic bullets in this sort of thing. But it's definitely an interesting starting point. And the researchers involved in this study are planning a very large clinical trial to see how this would work in humans. So there's maybe something here, but I don't think we're quite got that magic bullet yet.
Shamini Bundell
But that's so interesting, just the fact that it works sort of all the way from sort of C. elegans to rhesus macaques across that wide range of, of species. It's fascinating. And so yeah, I'm gonna be very interested to see what the results of this clinical trial are when they come out.
Nick Petrić Howe
Definitely. It's certainly an intriguing result. But I'm also intrigued by what you've brought for the briefing this week. Shamini.
Shamini Bundell
Oh, very nice. Okay, so this is something that's maybe not going to come as such a surprise to people who've worked in science, and particularly in trying to get papers published. I don't know if you've got an experience of this, Nick, but often when you publish a paper, you submit to a journal, that journal has submission formatting guidelines that says, you need to have these kinds of sections, this many words or characters for a title, all sorts of things like that.
Nick Petrić Howe
Yeah, no, unfortunately, I'm quite familiar with this. All the drafts of my papers are in a drawer somewhere I never quite published, but I'm familiar with the process. And yeah, sometimes this sort of changing the format of your manuscript for submission, can take a very long time because journals have very different requirements. And even minor things like word or page limits can mean that you really have to drastically change a lot of things to try and make it work for that journal. So yeah, I think a lot of people will be a bit like, oh, yes, this is definitely a problem.
Shamini Bundell
So, some researchers have actually published a paper about this problem in BioMed Central Medicine and I've been reading this Nature news article about it. And what they've done is they've basically tried to calculate the cost of how much all of this — basically reformatting your paper every single time you submit to a different journal or get rejected and have to submit somewhere else — how much money, essentially, is all that time spent reformatting worth. And the figure they came up with was okay, in 2021 — this is for papers sent to biomedical journals specifically — they've calculated 230 million US dollars’ worth of time was essentially wasted reformatting papers.
Nick Petrić Howe
230 million? That is... I mean, it's not surprising, but to see it all put together, that's a large number — and that's only a section of science as well. So I guess this is a bigger number, when you think about science writ large. I mean, that's obviously a huge amount of time and money going to waste. So they have any sort of suggestions about what we can do about this?
Shamini Bundell
Yes, I mean, they have made the obvious suggestion, which is that journals should allow free format submissions, so that researchers can spend their time and money on research instead. And they make the point here that a lot of these formatting requirements could be sort of hangovers, from the days when this was all intended for print, which lots of journals aren't anymore. When you're sort of having to send your journal to press, you have a lot of specific requirements that you do need. There's also the fact that having something in a standard format for your journal might make it easier for the editor to initially assess, potentially for the peer reviewers to assess. However, you know, a big question is does that work need to be done at the submission stage? Or is all of this formatting something that would be better off coming once a paper has been accepted? At which point, you know, researchers interviewed for this article say they don't mind doing all that formatting, as long as it's after their study has actually been accepted.
Nick Petrić Howe
Yeah, no, I guess that's a good point, because otherwise people are just spending all this time reformatting. And then they may not even get the paper published in that journal and have to do the whole process again.
Shamini Bundell
Yeah. And one of the researchers interviewed said that this would disproportionately affect early career researchers, because when people are more established, they might have a whole team who could sort of help out with that.
Nick Petrić Howe
I guess, though, as you say, like sometimes having these formatting to make things easier for the editors, and maybe the peer reviewers as well. So, do you think, or does this article have any suggestions for how likely it is that journal is going to be receptive to this?
Shamini Bundell
Well, they've said that they're planning to launch an aggressive outreach campaign to sort of relevant organisations, they've got an online petition, as well. But there might be some sort of compromise to be had. In talking with sort of scientists and journal editors, one of the things that they recommend would be a sort of middle ground between totally free format, which could be completely wrong for a particular journal, and really strictly formatted. So there might be you know, something like a minimal structural requirement, like a total word count. And that's what people have to abide by, or trying to make those kinds of things consistent across different journals so that when you're sort of submitting to multiple places, you're not having to reformat — that would be really useful. But there's another quote in here from a sort of editor-in-chief of a journal who says that, you know, there are thousands of journals, they have different audiences and personalities, and thinks that it is often appropriate for them to have different requirements, particularly for things like word count. Interestingly, this is a Nature news article, but they also got a quote from Nature's journal team — those two things being editorially independent from each other — and the Nature editor-in-chief said that the initial format of a submission doesn't influence the consideration of the manuscript. Although Nature does have formatting guidelines on its website.
Nick Petrić Howe
Well, I'm sure a lot of researchers will be happy to put a number on this amount of wasted time because I'm sure it's a feeling many of them have. So thanks for bringing that to the Briefing Chat, Shamini. And listeners, for more on these stories, and for a link of where you can sign up to the Nature Briefing to get more like them, check out the show notes.
Shamini Bundell
And that's all for this week's show. As always, if you want to get in touch, you can reach us on Twitter. We're @NaturePodcast, or send an email to podcast@Nature.com. I'm Shamini Bundell.
Nick Petrić Howe
And I'm Nick Petrić Howe. Thanks for listening.