The Royal Society Summer Science Exhibition

Bees, body odour, and beaming pictures from space: we've gone behind the scenes of this year's digital fair
20 July 2021
Presented by Chris Smith, Eva Higginbotham
Production by Eva Higginbotham.




It’s the Royal Society’s annual Summer Science Exhibition, but with a digital difference. We go behind the scenes to hear whether bees have favourite flowers, and discover smelly science of your armpit microbiome...Plus, in the news, the data on masks is mixed; might it be that most people aren’t using them properly? Also, are “ice berg basements” why Brian May’s home flooded in London? And an app that can spot anaemia from a selfie...



In this episode

A woman wearing a facemask.

01:06 - Masking for COVID: fit for purpose?

With mixed data on the effectiveness of masks, are people just not wearing them properly?

Masking for COVID: fit for purpose?
Eugenia O'Kelly, University of Cambridge

First they weren't introduced. Then they were mandatory; then, with ‘freedom day’, they weren't, and now, confusingly, in some parts of the country you'll have to go by whatever rules the local councils and businesses are putting in place... for face coverings. So why the controversy, and what's the evidence that these things actually work? Well as engineer Eugenia O'Kelly - who heads up Cambridge University's Respiratory Protection Engineering Task Force - explains, the signs are that they can make a difference, but most people aren't wearing them properly, and that's limiting their effectiveness. So are they “fit” for purpose? Chris Smith found out...

Eugenia - There are two purposes that a face covering can serve. One is to protect others, and the second purpose is to protect yourself. In terms of protecting others, the face-covering will prevent any sort of droplets that you exhale from being distributed around the environment. The second purpose of a mask is to protect yourself. And if you're wearing a mask to protect yourself, the engineering challenges of that are quite a bit higher. You actually want to be filtering all the air that you're inhaling. And for that, you have to have a material that has high enough filtration ability that it's going to be catching a sufficient number of viruses or pollutants. And secondly, and more challengingly, it has to fit well enough that air isn't just going to be leaking around the sides of the mask.

Chris - Is not another problem that when doctors, nurses, other healthcare workers in hospital use close-fitting masks designed to exclude viruses in the body, they're combined with other elements of personal protective equipment, such as aprons, gloves, scrubs, eye protection, the idea being that there are multiple routes into the body via various direct and indirect pathways, and you've got to close off all of them, or it's not worth the additional protection of these very, very stringent masks.

Eugenia - Yes. I would say that if you're really looking for a hundred percent protection, you need additional measures and we're doing a project right now on the amount of droplets that, through normal speaking, end up in the eye area and how different types of glasses that an average person might be wearing may block that. You certainly get quite a few droplets in the eye area when you're normally speaking with someone. And another thing to keep in mind is these healthcare workers, even with just the masks that they have, they have gone through procedures to ensure the masks and the other PPE fit and work. So it's perhaps an unfair standard to expect for your average citizen.

Chris - When people do experiments to work out whether or not masks do arrest a lot of the stuff that's coming through them, do they actually do a comprehensive experiment where they look from behind as well as in front? Because a lot of the studies I've seen have just been looking from the side, looking at stuff being projected forwards. And they're ignoring the fact that I mean, a lot of my colleagues who put face coverings on at work and wear glasses, their glasses are incessantly steaming up. Now that's showing you that there's a lot of material blowing up over the upper part of the face and is not being stopped by a face covering. So how good are your average face coverings at actually stopping these droplets?

Eugenia - I think that's a very good point and one perhaps very good visual of how much escape you can get around the sides of the mask is if you watch someone in a very cold environment, you can see the vapor from your breath escaping around all sides of the mask is significant. And that's really a sign of poor fit. And while those masks are likely to hinder very large droplets that you're projecting when you're speaking, it's not really fitting well enough to filter those smaller particles.

Chris - Do you have a feel for, if you take a person at random off the street who is wearing some kind of face covering, how effectively they are wearing it?

Eugenia - Well, unfortunately at this point we don't have a significant enough sample size that we can really make that assessment. What we have done is we have created a tool so that if you're wearing a higher efficiency mask, such as a surgical mask and FFP2 mask or FFP3 mask, you can at home perform the same type of tests that a hospital performs on its workers to make sure that their masks fit.

Chris - Did you try it on yourself?

Eugenia - Yes, I did. Most of the experiments we've done I've tried on myself while working out some of the kinks.

Chris - And were you masking effectively?

Eugenia - I was not actually. So I tried it on five different masks on myself. And what surprised me was especially given the fact that I've been working with this, reading all of this literature, doing these studies, there were masks I thought fit, and when I tested them, they didn't.

flooded road

06:52 - How do flash floods happen in cities?

The Queen guitarist Brian May has had his basement flooded with stinking black sewage. What's the cause?

How do flash floods happen in cities?
Linda Speight, University of Reading

Brian May, the guitarist from the band Queen, posted videos this week on social media of an overflow of sewage that had risen through his basement. Stinking black sludge flooded the floor, destroying most of the childhood photos and memorabilia that were stored there. And many others in his area of London suffered similar - or worse - fates. The cause? Well, Brian May blames a rise in construction of mega-basements - so-called ‘iceberg basements’ that, like icebergs, feature many stories hidden below the surface. Supposedly, these structures stop groundwater from properly draining. But is it true? Phil Sansom spoke to flood forecasting expert Linda Speight from the University of Reading to find out what actually happened...

Linda - In London, on Monday, there was a really heavy rainfall event, kind of the average rainfall that's normal for the whole of July fell in just a couple of hours. The impact of that caused flooding across the area. Really lots of different areas of London were showing videos of flooded streets, flooded basements, flooded rainfall stations. I believe that's the expected outcome from that amount of rainfall in such a short amount of time.

Phil - Of course, the consequence for people like Brian May is that stuff that's in basements can be damaged or destroyed.

Linda - Yeah. Brian May, unfortunately, this week, suffered the experience that many people across the country suffer when flooding happens and it's a really devastating and emotional time that your property and your personal belongings and things that hold value for you as an individual get destroyed in the floodwater.

Phil - And Brian blames it on, in Kensington where he lives, the so-called epidemic of people building huge mega basements many stories down beneath their houses. Is that a reasonable thing to blame it on?

Linda - I think when this kind of flooding happens people are really keen to find somebody or something to blame. And there clearly has been a lot of basement conversions and basement development across London. And the reason for this is because there's no other space to build in the area, and the same is true of rainfall. So when it rains a lot in London, there's nowhere else for the water to go. There's lots of hard surfaces, and when the rain hits hard surfaces, it can't soak into the ground like it would do if it was falling in the countryside or on fields and grass and woodland areas. So that means, unfortunately, where people have built basements, they've actually built something that's below ground level and the water wants to try and get to the lowest place possible, so it flows into the basements.

Phil - So is it these big basements that are letting this water build-up and creating the hard surfaces that prevent it from draining properly?

Linda - It's not necessarily the basements, it's just development in urban areas in general. I wouldn't like to say that basements have made any difference in this event, that amount of rainfall would have caused flooding anyway. They may or may not have contributed to it, but they're unlikely to have been a significant factor. It's more generally the fact that there is no space for water in our cities. And when it rains a lot, like we saw last week, the water naturally has to flood because there's nowhere else for it to go.

Phil - So even if more and more basements aren't the problem here, are these kinds of floods still getting more common?

Linda - Anecdotally, it would seem that we are experiencing more of these heavy rainfall events in the last few years. And the climate change predictions seem to be backing up this statement, saying that as the atmosphere warms, then these kinds of events will get more frequent in the future. And the reason for that being warmer air can hold more water. That means that when it rains, there's more moisture in the atmosphere and therefore more rainfall falls very quickly, and we see these heavy, intense rainfall events increasing in the future.

Phil - And how often is that likely to overwhelm a city's drainage like we've just seen?

Linda - Cities in the UK have what we call combined sewer systems. That means that both our dirty water and the rainfall flow into the same sewer system. The problem is that the way we've designed those systems uses historical rainfall data. And as I've already said, we're seeing more and more of these events, and more intense rainfall is predicted in the future. So what was once a once in 30 year event may soon become a 1 in 20 year, 1 in 10 year event, and the sewer systems are likely to get overwhelmed more frequently.

Phil - I mean, what do we do? Because these sewer systems are built beneath a city. It's not as if you can just lift it up and enlarge everything and then put it all back down again.

Linda - Nope. It's probably not practical to redesign our sewer systems, though we might be able to do that in small areas, we're not going to be able to do that across whole cities across the whole country. So what we need to do is actually make people more aware that they are at risk of flooding. And as you can see from Brian May story, it's really devastating when it does happen to you. So in the UK, we're quite good now at forecasting these types of events - the MET office did issue a heavy rainfall warning for the flooding on Monday. And what we need people to understand is when they see these kinds of warnings, they need to start taking action. That might be that they don't want to keep their best possessions down in their basements where the water's naturally liked to go. They could also think about installing flood resilient defenses onto their properties - small gates that they put across their doorways, or making their property, in general, more resilient. Moving their plug sockets higher up, putting damp-proof courses in, and things like that. So there's lots of proactive ways people can take action themselves to help protect themselves from the impacts of flooding.

Dog drinking from a water bowl

12:57 - Dogs don't return the favour

When given the option, dogs didn't reciprocate feeding the humans that fed them

Dogs don't return the favour
Jim McGetrick, The University of Veterinary Medicine in Vienna

You may share everything with your dog, from your bed to the food from your table. But recent research suggests that, unfortunately, those favours are not likely to be returned. Eva Higginbotham spoke to Jim McGetrick from the University of Veterinary Medicine in Vienna... 

Eva - Many of us are totally enamored with our dogs and feel that we would do almost anything to keep them warm, happy, and importantly fed. And we might like to think that our dogs would return the favor, and, given the option, feed us too

Jim - After dogs have been trained to use a food dispenser, dogs experienced a 'helpful human', which provided them with food using the food dispenser, and an 'unhelpful human' who didn't provide them with food.

Eva - That's Jim McGetrick from the University of Veterinary Medicine in Vienna, and he set out to see if dogs would choose to feed humans by interacting with a food dispenser they themselves had been fed with. But, unfortunately...

Jim - The dogs didn't reciprocate the receipt of food. So regardless of whether the human had been helpful, providing food, or unhelpful, not providing food, the dogs didn't provide food in return.

Eva - Despite conventional wisdom that your pup is going to love whoever feeds them, the researchers also didn't see any difference in how the dogs responded to the people who either fed or didn't feed them. Though, Jim pointed out it may be that building that kind of relationship just takes some time.

Jim - It's important to note, in our experimental setup, it was an artificial setting. Let's say there was no communicative interaction of any note between the human and the dog. And there was also no physical contact, and with most natural cooperative interactions - so, for example, like you've seen primates grooming each other - you've got very clear physical interactions. So it's very difficult in those situations to ignore the fact, or to not notice the fact, that another individual is doing something nice for you.

Eva - So perhaps the dogs just didn't fully understand that they were being fed by a human and as such, it might be nice to return the favour. But do dogs even show these kinds of behaviours with other dogs?

Jim - Our group previously showed that dogs will provide food to other dogs in a similar setup. And what's interesting there is the dogs did provide food to partners, but only if those partners were familiar to them, in most cases, meaning from the same household.

Eva - Friends and family only then! Importantly though, food sharing just doesn't seem to be a natural behaviour for dogs, as many dog owners could confidently attest, unlike other animals, like some primates, for whom food sharing is the natural order of things. And it turns out the theories for how these behaviours arise in the brain are still not completely understood.

Jim - Previously it was generally kind of assumed that to reciprocate a cooperative behaviour you require a lot of complex cognitive abilities. For example, a very complex memory, the ability to stop yourself from consuming a particular resource so that you can give it to another individual, the ability to plan - to know that if I give you this resource, that that will result in me getting some resource from you in the future. Well, the tide has kind of shifted on how we view reciprocal cooperation or how it's likely that it comes about in animals. So now the view is more that most reciprocity in animals is probably a more emotionally based interaction. So for example, if you imagine two primates interacting, they groom each other. And this results in the development of a relationship, which as a consequence results in this kind of reciprocity with regards to grooming, but it's not necessarily the case that those two individuals are thinking about that and calculating, okay, well that individual gave me 10 units of grooming last time, I'm going to give them 10 this time. Or last time they gave me less than I give them, so I'm gonna, you know, change it. It's probably more likely that the receipt of grooming, or whatever other cooperative act, results in a positive attitude towards that individual.

Eva - So perhaps reciprocal behaviour in animals could be thought of more as a warm bond with another creature, as opposed to a calculated tit for tat. That said, if a dog wouldn't feed me in return, I might as well just stick with my cat.


17:23 - A new app to detect anaemia?

Researchers are using smartphone images of the inner eyelid to test for anaemia

A new app to detect anaemia?
Selim Suner, Brown University and Rhode Island Hospital

Anaemia is a common condition that makes you feel tired and weak. It’s caused by a lack of iron-rich haemoglobin that’s present in your red blood cells. People who lose a lot of blood, don’t eat a good diet, or have diseases that affect the ability of the body to produce red blood cells can all fall victim. Now anaemia is usually very easy to treat but often greatly underdiagnosed, mainly because, right now, the way you test for it is inconvenient: it involves taking a blood sample and waiting for this to be analysed in a lab. But now, researchers at Brown University have found a faster way to spot it, which can be done in literally the blink of an eye, as Sally Le Page found out by speaking with Selim Suner..

Sally - Okay, I've got my phone on selfie camera mode. I'm holding it as close to my face as possible, until it can no longer focus. I'm pulling down on my lower eyelid. And there we go, a terrifying image of my inner eyelid. Now, as a young millennial, I've probably taken more selfies than the average person, but this is a strange thing to be doing even for me. However, this may become a more normal activity in the future, as a team of researchers at Brown University and Rhode Island Hospital have figured out a way to use photos of people's inner eyelids to test for anaemia, as I heard from lead author Selim Suner.

Selim - There are blood vessels very close to the surface of the inside of the eyelid, and they come together to give the inner eyelid a red hue. And that's primarily what we're extracting from those images is that red hue, and using some fancy math and image processing to extract the redness of the inner eyelid and the less red it is, the more likely that that person has anaemia

Sally - Anaemia is a lack of red blood cells in the blood, and in severe cases can make you seriously ill or even be fatal. And anaemia is incredibly common too.

Selim - It's thought that about a third of the world's population is anemic to a certain extent, and this is more pronounced in developing countries and in countries where there are parasitic diseases such as malaria, and also nutritional deficiencies can cause anaemia as well.

Sally - Right now, the gold standard test for anaemia is a blood test, but Selim's team hopes to be able to develop this eyelid photography test into an app for any smartphone. But what's wrong with a simple blood test?

Selim - Well, you would have to make an appointment with your GP. They would have to order the test. You would have to go to a lab, get your arm or hand stuck with a needle and then wait for the results, which would probably take a few days. Whereas if you had this app, you can take a picture of your lower eyelid and have the results in seconds, it's that fast

Sally - Sounds simple, right? But is it accurate?

Selim- So our test is about 70 to 80% accurate in determining if someone is anaemic, and skin colour does not affect our results. So one use is that we could screen populations with this test and those that come up anaemic on our test would go on to get a blood test and get treated, so that would save resources.

Sally -
Are there any other ways this is more appropriate than a blood test?

Selim - In time-sensitive conditions, for example, after a car accident, this test could be performed with a phone in the ambulance. And if a patient is losing a lot of blood, then we could figure that out very fast.

Sally - I hadn't thought of that. I always think of anaemia as something that comes on gradually because of diet, but I suppose, if you're losing a lot of blood, you're very quickly going to become anaemic.

Selim - Absolutely, and that could occur from traumatic conditions where there's bleeding either internally or externally or from gastrointestinal bleeding, which is a common cause of anaemia.

Sally - You said anaemia is more common in developing countries, and I imagine it's much harder to get a blood test there, but are there enough smartphones with good enough cameras for your app to be useful in those countries?

Selim - Well, we've looked into that, and even though the number of people with access to portable phones with cameras is less in developing countries, this number is growing significantly over time, and it's not as low as people think. For example, in Africa, the penetrance of cell phones with cameras is about 30%.

Sally - It's going to take a bit more research to turn this image analysis into a simple app that works on the majority of phones and doesn't require any training to use accurately. So for now I can thankfully delete all of the photos of my inner eyelid from my phone, but I'll be keeping a close eye on how this develops over the next few years.

Sooty Tern Onychoprion fuscatus (syn. Sterna fuscata) flying in colony on Tern Island, French Frigate Shoals

22:59 - Bird wing colour affects flight efficiency

Heating seabird wings indicates how darker feathers evolved to reduce energy expenditure on long flights

Bird wing colour affects flight efficiency
Svana Rogalla, Ghent Uninversity

It’s well known that dark surfaces soak up more of the Sun’s rays than lighter shades, and now new research suggests some birds have evolved darker wings to take advantage of this heating effect and improve the efficiency of their flying. This is particularly relevant for seabirds like the Albatross that travel thousands of miles in a single journey. Harrison Lewis spoke to Svana Rogalla who’s been putting wings in wind tunnels to get a bird’s-eye view of the evolutionary advantages of darker feathers when it comes to flight...

Svana - There've been some studies suggesting that the heating of an airfoil, like a wing, can actually improve the flight efficiency. But until now there have been no studies on whether colour in birds can actually affect flight performance. So in my study, I found that darker wings will heat up more, and the hotter wing surface can actually increase the flight efficiency

Harry - And this is wild because you're saying that a darker wing is more efficient in terms of energy for flight, but most birds are completely different in colour.

Svana - Yeah, that's definitely true. So birds are amazing because they have all kinds of colours. These colours have different functions. So for example, very bright and shiny colours can serve for sexual signaling. But of course, not all birds are very colourful, so some are also more modal, so more like brownish grayish.

Harry - As a sort of camouflage, I guess?

Svana - That's camouflage, exactly. So in our study, we've looked at seabirds. Seabirds are mostly black and white, and we found that birds that are already efficient in flight have evolved darker wings. So already efficient birds can increase their efficiency even more by becoming darker and by flying under the sun.

Harry - Right, and how does one go about finding out if darker pigment in the wing helps with flight or makes flight more efficient? What are the steps?

Svana - What we did was to look at the wing in the wind tunnel. So we mounted the stuffed bird wing on a force balance, then we could measure the forces applying on this wing - so the lift and the drag, and does the heating of the wing affect the flight efficiency. So therefore we also mounted some light bulbs in the wind tunnel, so it would simulate a bird flying under the sun. And then we compared the heated wing with the non-heated wing, and we found that the heated wing is 20% more efficient.

Harry - And why is that?

Svana - So that's actually what we would need to test in the future, but we have some hypotheses. So it could be that the boundary layer, so the air flying around the wing, is delayed when the wing surface is heated. And, by the heating of the wing, it could be that the boundary layer is separated at an earlier stage, so that could make the flight more efficient.

Harry - When air passes over a curved surface, like a wing, it sticks to it. And in part, this is responsible for generating lift. But if it isn't optimal, it can actually hamper the efficiency of the wing's performance. Svana believes that heating the wing alters how long that passing air sticks to its surface, making the process much more efficient. So is one implication of these findings that we should be painting all our aircraft black?

Svana - Unfortunately it's not that easy. Of course, a plane will fly much, much faster than a bird. On the other hand, planes also store the fuel in the wings, so it's also not ideal to have the fuel in the wings heated up in that case.

Harry - That doesn’t seem ideal at all!

an old style alarm clock, faded with time

27:11 - A history of the Royal Society Exhibition

The exhibition has changed somewhat since the 1660s...

A history of the Royal Society Exhibition
Keith Moore, The Royal Society

For the rest of the show this week we’re going behind the scenes of the Royal Society’s Summer Science Exhibition which has been happening online this year - because of Covid... The Royal Society was established in 1660 by the acclaimed architect and astronomer Christopher Wren. It’s the oldest national scientific institution in the world, and exists to promote, fund, and advise on scientific matters. Although for many years its meetings took place behind closed doors, it later started putting on shows and demonstrations for the public of the latest scientific research, which would have been quite a spectacle at the time, as we heard from chief librarian, Keith Moore...

Keith - I would have loved to have gone to a 19th Century Royal Society exhibition. The place would have been fizzing with floral displays, displays of electricity...great scientists were there - so you might have talked to Michael Faraday or James Clerk Maxwell. And the exhibits were very eclectic, so yes there was great science there, but you might also have seen art by the latest pre-raphaelite painters or materials sent to the Royal Society from all parts of the world - so rough diamonds, rubies, manufactures of different countries, it generally was a mixed bag of things. So the great scientists of the Royal Society we’ve all heard of, people like Issac Newton, Benjamin Franklin, Howard Florey in the 20th century, Albert Einstein was a foriegn member. And it’s surprising how many of these people exhibited at the summer science exhibitions. Alexander Fleming, who developed penicillin, showed his early research at the Royal Society just after the first world war. So some very famous people have showed their science, and the summer science exhibition continues in that tradition.

A bumblebee on a flower

29:25 - What's a bee's favourite flower?

Using DNA analysis to unpick pollen preference in bees...

What's a bee's favourite flower?
Elie Kent, University of East Anglia

Animals have been a feature of the exhibition for hundreds of years as we heard from the Royal Society's Keith Moore...

Keith - There's a famous magazine illustration, which shows a lady looking at an electric eel in a case at the Royal Society. And they were administering shocks to visitors just to demonstrate the properties of the creature. Jimmy, the dog, who was the pet of Augustus Waller helped in the exhibitions as well. He demonstrated his own heartbeat from Waller's electrocardiogram and questions were asked in parliament about that. In the 17th century at Royal Society meetings, if someone discovered at a London market, for example, an interesting fish, they might well bring it into the Royal Society. In Newton's presidency, a German gentleman was given ten and six for making his dog talk, and apparently it was a very talented dog. It spoke in English, French and high Dutch.

Talking dogs aside, important research into animal behaviour is on display this year, specifically featuring bumblebees. Bumblebees are crucial pollinators in nature’s ecosystem, and farmers will even buy commercial beehives, plonk them in their fields, and hope they will do the hard work of pollinating their plants. But do they? Elie Kent is a PhD student from the University of East Anglia who has been trying to find out, as she told Chris Smith...

Elie - Hi. So we want to know which flowers the bees have been visiting on the farm. I've been working on soft fruit farms where you have a large area of one crop. So you might expect the bees to visit the most abundant flower, which would be the crop. But bumblebees can fly one kilometre to find food, and even farms have really diverse habitats with lots of different flowers in. So we want to know which flowers the bees have been visiting. And one way to do this is by studying the pollen the bees collect. So pollen is a really important part of the bees' diet because it's high in protein and fat, and bees make foraging trips where they collect pollen from flowers and take it back to their colony. So we can take that pollen from the bee and see which flowers the bees visited.

Chris - And how do you actually do that, Elie? How do you know which pollen came from which flower?

Elie - Previously it would have been done using microscopy, which takes a really long time and a lot of the closely related species look very similar...

Chris - So you mean actually putting bits of pollen under the microscope in order to identify which plant it came from, just on the shape and size of the pollen grains.

Elie - Yeah, exactly

Chris - Oh goodness. That sounds like a bit of a nightmare.

Elie - It is. It takes a really long time. I've actually had a go at doing it and I can confirm it's pretty time-consuming. So what we've been doing is looking at the DNA in the pollen. So we can use the DNA as a code, which is unique to each plant species, and then we can use that to identify the flower the pollen has come from.

Chris - What did you do then? Collect a whole bunch of bumblebees and scrape the pollen off and then get the genetic codes of all the pollen and then marry it up to flowers or plants?

Elie - Yeah, pretty much. I've done some fieldwork where I've collected about a thousand pollen samples from bees. And you can scrape off the pollen because they collect it into these balls on their hind legs. So it's quite easy to get. And then we can extract the DNA. And with this small device called a minION, it can take just a few hours to tell us what the pollen DNA is. And then like you said, we can compare the pollen DNA to plant DNA, and the ones which are most similar, provide that match.

Chris - So you can actually work out then basically what the bees have been dining out on. You'd better put us out of our misery. What do they actually go for? Do they do what the farmers want, which is to pollinate the monoculture of the one crop that's growing or do they think, "Actually I'm a bit bored of that. I'm going to go elsewhere"?

Elie - Of course, it's never that simple. Bees don't really have a favorite flower. It really depends on the species of bee, the time of year, so what's in flower at that point in time, what the landscape looks like, so how much of it could be agricultural or woodland. But what we do know is that bees do require really diverse diets. So whatever landscape they're in, they will be going to several different flower species.

Chris - In other words, if they were to get a restaurant of all the same fast-food chain, they would actually actively seek out to dine somewhere different from time to time. What can farmers do then given that their motivation is they want their crops pollinated, this will give them the best yields and that will make them the most commercial revenues. What can they do to tempt the bees to actually get the most efficient pollination?

Elie - So the results have shown that these do prefer some types of flower, and we can use that information to build up a more pollinator-friendly landscape. So we can plant more of these flower species in, say, hedgerows and field margins, and that will help wild populations of bees. And so that's sort of a win-win situation for the farmers because then they don't have to depend on buying bees. They can use this natural resource where the wild bees are doing the same job as the ones they bought.

Chris - Jeremy Clarkson did this in his farm series, I don't know if you've caught any of it, in his farming series. He actually literally mowed down the crops down in the middle of his field and planted a big strip of wildflowers. And the motivation was to try to tempt the pollinators into the middle of the crop rather than just from the edges.

Elie - Yeah. That's a really great idea to get more of these wildflower areas where you're getting flowers at all times of the year, not just when the crop is flowering. You're going to get a much more diverse range of insects, which will do the same job.

Chris - I never thought we'd be mentioning Jeremy Clarkson on the Naked Scientists. And just in 20-30 seconds, if people go online to see your exhibit, what can they find out about it? What can they learn about if they come to your exhibit, Elie?

Elie - So, we've got a short film where we talk in more detail about pollinators on farms and how we've been studying the DNA. And there's a short game where you can have a go at collecting the DNA. And there's also a citizen science questionnaire about how bee hotels are used by the public. So it'd be really fantastic to get lots of responses from that.

The bee hotel survey is now available, for more info please see:


36:00 - Armpit microbiomes: body odour and bacteria

How are smelly molecules created on human skin, and should we really be washing it all off?

Armpit microbiomes: body odour and bacteria
Gavin Thomas, University of York

With the summer heat we’re experiencing here in the UK, some may suspect they’ve been a bit smellier than usual? Well, that’s down to the bacteria that live in our armpits. We’ll hear more in a moment how understanding them better could lead to superior deodorants. First though, let’s hear from the Royal Society’s Keith Moore about how microscopes - and the formerly invisible world of microbes they enabled visitors to see - have always been a huge hit over the years...

Keith - Microscopes were a really important part of how science was demonstrated in the 19th century. And one of the great pioneers, Robert Koch the germ theory pioneer, sent specimens of tuberculosis, leprosy, and other bacteria for exhibition by William Watson Cheyne in 1882. And of course, later Koch would go on to win a Nobel Prize for his tuberculosis research. Visitors to the summer science exhibition would be able to look down microscopes and use them. They would see interesting things down there, perhaps minerals or small creatures, but scientists attending might be interested in the instrument itself. So instrument makers would demonstrate their wares at the Royal Society in the hopes that scientists might buy one of those instruments.

Of course a lab wouldn’t be a lab without a microscope these days, and some scientists use theirs to stare at what’s living in the average armpit. The University of York’s Gavin Thomas does just that, as he told Eva Higginbotham...

Gavin - It's the microbes that make us smell. And to understand that we need to think a little bit about what sweat is and the different types of sweat that there are. So if you look at our armpit, it's a very rich environment with different types of sweat glands, but the type of sweat glands that we normally see on our open skin, which are called eccrine sweat glands that make the kind of salty water we know that we use for thermoregulation, they are found in the underarm, but also another important type of glands called the apocrine glands. And these apocrine glands make different types of sweat, which contains a range of different chemicals, but also the odourless precursors that are acted on by bacteria to form the molecules that we know as body odour.

Eva - And what kind of bacteria are they that live in the armpit?

Gavin - We've discovered some particular bacteria called Staphylococci that were important in this process. There's lots of different types of bacteria that live in the underarm. We like to think of it as a bit of an oasis on the skin. So the skin has different parts, the open skin, scalp, for example, your feet and your underarms, they're all different environments. And they all have their own populations of microbes. So the underarm has a particularly rich set of microbes, very diverse set of microbes, and only some of those are actually able to make body odour. And we kind of pinpointed the ones that are able to do that.

Eva - And do those bacteria like to be in the armpits because they like to eat the molecules that are in that sweat you were talking about.

Gavin - Yeah, we think so. I mean, we haven't formally proven this yet, but we know that these odour precursors, when the bacteria take them up, they take them up first into their cells and then they actually partly break them down, and they eat the things that they're releasing. So they release nutrients from those molecules and then the final molecule that they can no longer use, they then spit it out. And that molecule is the volatile molecule that forms one of the most pungent components of body odour, which is called a thioalcohol. So we've been working on discovering how these particular bacteria recognise this odourless precursor, take it up, break it down, producing what we recognize as BO.

Eva - And does everyone make the same molecules and so smell the same? Because some people just are smellier than others.

Gavin - Yeah. That's a great question. There is a genetic basis behind this in terms of the amount of those odorless precursors I just mentioned, and how much you've actually made. So we know that there are some populations of people in the far east to have a genetic mutation in the enzyme that actually secretes the precursors into the underarm. So these people don't make, or don't secrete, as much of the precursors. And therefore aren't able to make so much thioalcohol. Now they do still smell, but they smell differently to a Caucasian person because they're missing that key component of the body odour. Body odour is made up of a range of different molecules. The thioalcohols that we study are the most pungent component. So without them, they actually smell slightly different to what a Caucasian person does. And also the actual population of microbes in the underarm clearly has an effect because we know that some people have produced higher or lower levels of actual body odour. So at least two things influence that.

Eva - And can we try and use this understanding of this breakdown of these molecules in these specific bacteria to try to make better deodorants and so people can smell less?

Gavin - Yeah. So that's what we're trying to do. And that's what our colleagues in Oxford are looking at. So because we've discovered how the bacteria take up those precursors and how they break them down, we can try and design targeted drugs that will inhibit that particular process. So that, we think, is better. If you look at current deodorants and antiperspirants which either kind of mask body odour or prevent the precursors being secreted, many of them contain a kind of general anti-microbial things like triclosan. These will kind of effect all the microbes in the underarm. And what we really want is to design something that will just specifically hit the microbe which we've discovered, which is called Staphylococcus hominis that makes the odour, so this information should be able to help us make a much smarter deodorant.

Eva - So we'd like some kind of very specific armpit antibiotic that would just knock out the specific, bad-smelly ones.

Gavin - Well, not even an antibiotic in that sense, we don't even need to kill the bacteria. We just need to stop that particular process. So the idea is that we really go in and stop the transporter from taking up the precursor. We're not killing the bacteria and we shouldn't be changing the microbiome too much. So it's a really, really kind of guided weapon to inhibit the particular process that leads to odour production.

Eva - So there you go. We often think about trying to keep our gut microbiome happy, but perhaps we should be thinking more kindly of our underarm microbiome. One of my questions is what is the point of all of this? Is there any reason that the bacteria should be in our armpits breaking down these molecules in this very specific way? How could this have evolved?

Gavin - Yeah, that's a great question. I mean, that's what we're really trying to understand now because we understand which bacteria do it, how they do it, but not why they do it. So our research has suggested that the production of this thioalcohol molecule is, is a pretty ancient process. So it certainly predates our split from other higher apes. So it's been among us all the way through human evolution, and we know that other mammals use microbially-derived volatile chemicals to communicate with each other.

Eva - Is that what a pheromone is?

Gavin - Exactly. That is the definition of a pheromone. It's a volatile chemical that's used to communicate between animals of the same or potentially different species. So these might be human pheromones in our evolutionary past. They might've been important to humans in terms of communicating.

Eva - And do you think they could be important to humans in communicating now? Is there anything we could be doing by being quite clean these days and washing our armpits and applying deodorant? Could there be some benefit that we're missing out on?

Gavin - That's a difficult question to answer. I mean, we know that if you go back a couple of hundred years, we all had a strong odour that would have been part of our personality, our character. And then the Victorians come along. They associate odour with illness and therefore as part of cleaning up the cities and the environment they get rid of smells. Smells are linked to disease. And that, on the whole, is a very sensible thing to have done. So we have an environment now where we have a lot fewer smells in our environment. And again, in the early 20th century, a lot of soap companies really rammed home the idea that BO was bad to sell their product. So it's difficult. Is this conditioned in us is, is BO really actually bad? And again, I always like to make this nice quote that Napoleon famously apparently wrote to Josephine when he was returning from the battlefield where he said, "I'm coming home, don't wash." So clearly for Napoleon, the unwashed smell of Josephine had a positive association for body odour. Whether there's any direct benefit now, it's difficult to say

Eva - So more research to be done then. So Gavin, what can people see if they check out your stall online?

Gavin - So we've got a great arcade game called backman. You can play a Staph. hominis, it's the bacterium I've been talking about. You can go around and try to defeat the other skin microbiome and eat odour precursors. And on the website, you can read much more about the science behind what I've just been talking about. And also there's a quiz there too. And also some videos from the Oxford team saying about how they're developing these new drugs to try and reduce body odour.

An underwater view of the ocean surface.

44:43 - Marine plants measured from space

With up to 30m precision, scientists can track carbon locked away by marine microbes from space

Marine plants measured from space
Gemma Kulk, Plymouth Marine Laboratory

These days we take for granted that we can take pictures of the earth from space, whereas in the past scientists were chiefly focused on taking pictures of space, from earth! As we heard from the Royal Society's Keith Moore...

Keith - Photography was an important part of the 19th-century summer science exhibition. So people like Norman Lockyer the astronomer would demonstrate very regularly photographs of the latest discoveries. But also this is an area where some women scientists got involved. The Irish astronomer Annie Maunder showed her photographic skills at several summer science exhibitions in the 1890s. So this was an exhibition that women were beginning to participate in as well as men.

And nowadays we can look down on the Earth using cameras mounted on orbiting satellites. This can be used to study weather patterns and predict storms and heatwaves; monitor how the continents are moving and where volcanic eruptions might be brewing; or where pollution and other gases go. Another group is using this technology to find out how tiny marine green plants called phytoplankton take up the carbon dioxide we pump into the atmosphere. Gemma Kulk is from the Plymouth Marine Laboratory and spoke to Chris Smith...

Gemma - It seems like a huge contradiction that we can see phytoplankton from space because indeed they are so small, but collectively, so all phytoplankton together become visible through their impact on the colour of the ocean. So the greener the water, the more phytoplankton there are. So similar to plants on land, phytoplankton are green.

Chris - And what are they actually doing with the carbon? How is the carbon going from the atmosphere and ending up in these plants in the ocean then?

Gemma - So phytoplankton photosynthesize. So if you are familiar with the process of photosynthesis, that means that phytoplankton use sunlight, so energy from the Sun, to convert carbon dioxide and water into oxygen and organic particles.

Chris - And so if they're doing that to grow, is your sort of inference then that the greener the water is the more they're growing and therefore the more carbon they must be using?

Gemma - Exactly. That's true.

Chris - And how precise is that? So if I've got a camera watching the ocean, how subtle is the difference in greenness and how accurately does that map onto what the phytoplankton are actually doing when you look from space?

Gemma - The satellites that we are using in the open ocean, such as the North Atlantic ocean, for example, have a resolution of 300 metres. So for every 300 metre by 300 metre square, we have an image, we have data available. If we look closer to the coast, we have a resolution of up to 30 metres, which is very high resolution. So we can see phytoplankton in quite a lot of detail. And the colours; it's not just a green colour that is measured, but there are different colours that we use to identify phytoplankton. So yeah, the precision is quite high.

Chris - And what are you learning through doing this? Have we spotted anything that we didn't realise before, or are you able to just confirm "Yep, we pump out CO2, it goes into the atmosphere and it ends up in the ocean"?

Gemma - Well, I think that's true, but what I find really exciting about my work with satellites is that we can watch the entire ocean at a global scale for very long periods of time. So the ocean colour satellites that we now have, have a record of over two decades. So over 20 years of data, which is really exciting because we can watch phytoplankton over those two decades and see what happens. So what scientists originally thought was that maybe phytoplankton globally was decreasing over time, so there's less phytoplankton now than there was 20 years ago, but we don't actually see that at the global scale. It seems to go up and down a little bit. So we don't see a clear trend or clear decrease or increase.

Chris - Now we heard earlier in the program about the issue of climate change and you know, that's never far from anyone's mind, is it? Can this be useful in terms of monitoring where carbon's going and how we mitigate against climate change? Because we think carbon's at the root of climate change, don't we?

Gemma - Yes, definitely. I think the oceans play a really important role in the global carbon cycle and we often forget about it because it's not very visible. But phytoplankton take up about 50 gigatons of carbon each year, which makes them equally important to all plants on land. So they're really essential. And that also means that they play a role in climate change. What we do not know yet is how phytoplankton respond to climate change because our time series of over two decades is not quite long enough to understand the changes that are occurring at the sort of climate change scale. So this is something that we have to wait for. We gather more data, but it might take us another 10 years to have a better understanding of that.

Chris - Of course, something we don't have to wait for is to come and visit your virtual stall for the Royal Society summer exhibition this year. So what will I see if I come and inspect your wares?

Gemma - Hopefully you will see lots of phytoplankton, but there are also other things to see. So people can explore the global carbon cycle from space, not only in the oceans, but also how carbon moves through the atmosphere and is stored on land. It was very much a collaboration between different scientists, so we are looking at the total global carbon cycle.

A pomeranian dog.

QotW: Why don't dogs get hairballs?

Sally Le Page spoke to three animal aficionados: Nick Sutton, Science Communications Advisor at The Kennel Club; Justine Shotton, Junior Vice President at the British Veterinary Association; and Ann Hohenhaus, Staff Doctor at NYC’s Animal Medical Center

Nick - Contrary to popular belief dogs do sometimes get hairballs, as can rabbits, ferrets, cows and even humans. When animals groom themselves, any hair they swallow usually passes through their digestive tract and is excreted in their faeces. If too much hair is swallowed, or if it wraps around any food items, it can form a clump that’s too big to pass out of their stomach. As more hair is swallowed it clings to this mass and begins to grow in size. Once it’s big enough to cause discomfort the affected animal will usually vomit it up (so long as they have a vomit reflex, unlike cows and other ruminants).

Sally - You know, I had never thought about whether cows can vomit until now. Of course, cats famously get hairballs, so why is Beth’s dog hairball free when her feline friends aren’t?

Justine - Hairballs are a lot less common in dogs than cats, and this is for a number of reasons. First of all, dogs do lick themselves, particularly their paws for example, but don’t groom their whole bodies in the same way that cats do. Cats have tongues with small backwards pointing spines which help them to groom their entire bodies, picking up a lot of fur in the process, particularly if they are long-haired.  Dogs’ tongues are much softer as will know if one of your canine friends has ever given you an affectionate lick!

Sally - And it’s not just that cats swallow more fur than dogs, but they also struggle to digest it more, as Ann explains:

Ann - Cats are obligate carnivores, meaning they are designed to eat meat. Carnivores have a shorter digestive tract than omnivores because it is easier to digest a meat diet than a vegetarian or omnivorous diet. Dogs are omnivores and thus have a longer digestive tract which may digest hair more efficiently.

Sally - And finally, it’s still worth keeping watch if your dog does get hairballs:

Nick - Although it’s unusual for dogs to get hairballs, they may be more prone to them if they have longer hair or lick themselves more often. If your dog does get a hairball it could be a sign that they are licking themselves to relieve stress or anxiety, or to soothe any areas that are painful, uncomfortable or itchy.

Justine - If you notice your dog vomiting up hairballs or passing a lot of hair in its poo... always speak to your vet for advice.

Sally - Our next question of the week is this short but puzzling question from Henk:

Henk - Is lava wet?


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