Host: Benjamin Thompson
Welcome back to the Nature Podcast. Coming up this week, the US restarts research on gun violence…
Host: Shamini Bundell
And the sea sponges that control currents. I’m Shamini Bundell.
Host: Benjamin Thompson
And I’m Benjamin Thompson.
[Jingle]
Host: Benjamin Thompson
First up on the show, despite well-documented problems with gun violence in the US, there’s been a shortage of research into this topic. That is beginning to change though. Reporter Nick Petrić Howe is here with more.
Interviewer: Nick Petrić Howe
According to the Centers for Disease Control and Prevention, in 2019, 16.1% of all injury-related deaths in the US were associated with firearms. That’s more than 100 people a day – more than die from traffic accidents.
Interviewee: Asheley Van Ness
The US gun homicide rate is 25 times that of other high-income countries.
Interviewer: Nick Petrić Howe
This is Asheley Van Ness, the director of criminal justice at Arnold Ventures, an organisation that funds gun-violence research.
Interviewee: Asheley Van Ness
In 2019, about half of all gun homicides took place in about 127 cities, which represent about a quarter of the US population. And within these cities, gun homicides are most prevalent in racially segregated neighbourhoods with high rates of poverty.
Interviewer: Nick Petrić Howe
Despite the tens of thousands of people that die each year, there’s relatively little known about gun violence in the US.
Interviewee: Asheley Van Ness
Well, for decades, basic questions about how to prevent gun violence have just gone under-researched. So, for example, you can’t necessarily answer questions of, ‘How do people obtain guns?’ We don’t where the guns used to commit shootings actually come from.
Interviewer: Nick Petrić Howe
This knowledge gap has largely been attributed to a lack of federal funding. Due to a bit of legislation known as the Dickey Amendment, funding from the federal government on gun-violence research was practically frozen for 20 years. But in 2018 this amendment was clarified, and now researchers are able to get a piece of US$25 million of federal money for gun violence research for the first time in almost a generation.
Interviewee: Lisa Wexler
Well, I think it could save lives. The impact for this kind of research can be nearly immediate.
Interviewer: Nick Petrić Howe
This is Lisa Wexler who answered the National Institutes of Health call for projects on the topic of gun violence. Lisa works with the Indigenous people of Alaska, a population for whom guns are very important, and she is well aware of how controversial any discussion of gun use can be.
Interviewee: Lisa Wexler
It intersects with things like self-determination, with things like personal rights and freedoms. All of those things get mixed up when we start talking about guns in this country, and that is amplified in Indigenous communities who literally have been dealing with the government in ways that have restricted their access to food, so hunting restrictions, that have restricted their access to land, traditional lands that they have been moved off of. In Alaska that’s a little bit different but still, there’s a lot of narratives that link these things and think about the government as restricting freedoms, both tribal freedoms as well as individual freedoms.
Interviewer: Nick Petrić Howe
But access to guns can also have another side.
Interviewee: Lisa Wexler
Having a gun in your home increases your risk of suicide by three.
Interviewer: Nick Petrić Howe
Suicide is the leading cause of death for Alaskan Native men under the age of 24, and suicides are often committed using firearms. And so, in her work, Lisa is using her new found funding to search for a balance, working with communities to find out if promoting safety measures, like locking guns away in cabinets or making sure they’re not left loaded, could protect their young people from suicide, without restricting access to firearms per se.
Interviewee: Lisa Wexler
If you can make it ten minutes harder to get a lethal means – in this case, a loaded gun – you can save lives because a lot of suicides are impulsive, particularly youth suicides, and so if we can just slow that process down, give more opportunities for alternative ways forward, we can actually stop suicide from happening.
Interviewer: Nick Petrić Howe
Maeve Wallace is another researcher that answered the National Institutes of Health call for projects. In her research, she works with pregnant people.
Interviewee: Maeve Wallace
So, it might come as a surprise to many people but homicide is actually a leading cause of death among pregnant and postpartum women, and most of those homicides are by gun. So, it’s a leading cause of maternal mortality and therefore a relatively big issue in this field.
Interviewer: Nick Petrić Howe
Little is known about how to protect these people from gun violence and so when new funding became available, Maeve saw an opportunity
Interviewee: Maeve Wallace
So, I proposed to evaluate state-level policies that pertain to restricting acccess to firearms by persons involved with domestic violence. So, not only do we know that most homicides of pregnant and postpartum women are by firearm but they’re also most predominately committed by an intimate partner, so someone that has been involved with domestic violence against their partner. So, state laws that I’m looking at as possible ways that states can implement laws to prevent maternal mortality due to homicide are firearm restrictions or prohibited possession of firearms among people who have been convicted of domestic violence or among people who are under domestic violence restraining orders.
Interviewer: Nick Petrić Howe
By looking at the rates of maternal and postpartum mortality across states with different rules on restricting firearms, Maeve hopes to get an idea of the sorts of legislation and policy that would be most effective in protecting people.
Interviewee: Maeve Wallace
Preliminary, what we’ve found supports our hypothesis. States that are enacting these laws are seeing a reduction in homicide in subsequent years.
Interviewer: Nick Petrić Howe
Both Maeve and Lisa are appreciative of the new federal funding now available, as they hope their research could save lives. But it’s only the start. There’s still many basic questions that we don’t have answers to. Moreover, the infrastructure for collecting data on gun violence is pretty under-developed. Here’s Asheley again, who you heard form earlier.
Interviewee: Asheley Van Ness
There’s a huge gap there as well and without government support, researchers really can’t do much work without that government data. Unlike the database for motor vehicle fatalities or surveillance systems for HIV, systems for tracking firearm casualties are just incomplete. And so, one example that we think is an urgent question is something around gun ownership. So, in 2001, 2002 and 2004, our Centers for Disease Control measured the problems of gun ownership through a survey called the Behavioral Risk Factor Surveillance System. And the CDC removed questions on gun ownership following the 2004 survey.
Interviewer: Nick Petrić Howe
Back in 2019, US$25 million of new funding was a welcome change for researchers concerned about gun violence in the US. But many say it’s not enough. President Biden has suggested doubling that US$25 million each year but after a 20-year gap, there’s a lot of ground to cover.
Interviewee: Asheley Van Ness
We really thought US$25 million each year falls short of federal funding in terms of other fields of public health. So, what I mean by this is, we see that motor vehicles and firearms kill a similar number of people on an annual basis but unlike firearm deaths, the government invests $90 million each year in studying vehicle fatalities.
Interviewer: Nick Petrić Howe
Regardless of how much funding ends up being released, research in gun violence has a lot of catching up to do, and plenty of researchers are ready to take up the challenge. Here’s Lisa again.
Interviewee: Lisa Wexler
We’ve under-studied firearm violence and we’ve done it in such a way that has sort of not allowed us to see possibilities where there might be. So, I think for me it opens up some really possibly impactful ways to be thinking about reducing risk that can have really soon consequences instead of the really long-term work that also needs to be done. That’s really exciting to me.
Host: Benjamin Thompson
That was Lisa Wexler from the University of Michigan in the US. You also heard from Asheley Van Ness from Arnold Ventures and Maeve Wallace from the Tulane School of Public Health and Tropical Medicine, both also in the US. You can find out more about how gun-violence research is changing in a Nature feature article published this week. And we also covered this topic last year in our science and politics series Stick to the Science, which is well worth a listen. We’ll put a link to both of them in the show notes.
Host: Shamini Bundell
Coming up, we’ll be hearing about how the unusual structure of a sea sponge helps it to guide deep-sea currents. Right now, though, it’s time for the Research Highlights with Dan Fox.
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Dan Fox
Strategic laziness and a diet of yak dung have been found to help a round-eared relative of rabbits to survive harsh winters at high altitude. The plateau pika live at elevations between 3,100 and 5,000 metres on the Qinghai–Tibet plateau, where the air is thin and winter temperatures often drop below −30 °C. To understand how these mammals survive, researchers filmed pikas and implanted them with temperature sensors. They also injected the animals with water bearing a distinctive isotope to assess their metabolic rate. The team found that, on average, plateau pikas can lower their daily energy expenditure by almost 30% in winter. They also rely on an unexpected but nutritious and easy-to-digest food that they can access without expending too much precious energy: domestic yak faeces, which local people also use as fuel. Lower your energy expenditure and relax while you read that research in full in Proceedings of the National Academy of Sciences of the United States of America.
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Dan Fox
More than a quarter of food produced for human consumption in China gets lost along the supply chain or lands on garbage heaps. A team of researchers reviewed field surveys and published literature to estimate that around 350 million tonnes of China’s annual farm product is discarded by retailers, restaurants or consumers — or is ruined and disposed of before reaching retail. The scientists say that food waste on such a large scale threatens environmental and sustainability goals. To reduce waste, the authors suggest, among other steps, that rural Chinese households use more efficient storage systems and that urban restaurants reduce portions and encourage patrons to take their leftovers home. Chew on that research in Nature Food.
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Host: Shamini Bundell
Next up, reporter Ali Jennings has been diving down to the deep ocean to uncover the skeletal secrets of a sea sponge.
Interviewer: Ali Jennings
Hundreds of metres below the surface of the ocean on the abyssal seabed, a delicate lace cylinder sits in the darkness. Euplectella aspergillum (also known as Venus flower basket) is a deep-sea sponge supported by a remarkable skeleton – criss-crossed filaments of silica glass that form a lattice, around which grow the sponge’s cells. The result is a hollow cylinder peppered with holes through which the ocean currents flow. The flexibility and resilience of this sponge’s skeleton have long been studied. It’s elegant structure allows it to survive the buffeting of the deep-sea currents that might otherwise tear it loose from the ocean floor. But what has remained unknown is how the sponge’s structure affects the water that flows around it.
Interviewee: Sauro Succi
That’s precisely the point of the paper.
Interviewer: Ali Jennings
This is Sauro Succi, a researcher from the Italian Institute of Technology.
Interviewee: Sauro Succi
We are experiencing the way fluid moves, and so it was pretty natural for us to ask, ‘Okay, but how does hydrodynamics affect the living conditions of the sponge?’
Interviewer: Ali Jennings
But studying the intricacies of water flow on a sponge sat a kilometre under the sea is not simple, so Sauro and his team decided instead to simulate the sponge and the water surrounding it on a computer. In fact, on one of the most powerful supercomputers in the world.
Interviewee: Sauro Succi
In order to see the hydrodynamic patterns, we have to solve of the order of 50 billion equations because we have just to describe the geometry of the sequence of little cubes, and these cubes have to be small enough to capture the geometry. That’s why you need so much computational power.
Interviewer: Ali Jennings
Sauro’s simulation worked out how the speed and direction of the water currents change as they flow over and through the Venus flower basket.
Interviewee: Sauro Succi
It’s an enormous amount of information but let me tell you that before you look at the numbers, what you look at are really pictures, and you want to see the swirling patterns of the water as it moves around and inside the sponge.
Interviewer: Ali Jennings
One of these swirling patterns of water is called a vortex. When a vortex collides with a structure, it exerts a force on it called drag that could damage or dislodge a sponge. Flow of water around the sponge’s cylindrical shape causes such vortices to form, but the simulations revealed something surprising – the holes in the sponge were counteracting this problem.
Interviewee: Sauro Succi
The strategy that the sponge implements is sophisticated because actually it generates vortices but then they are launched far behind the structure itself so that the structure is preserved.
Interviewer: Ali Jennings
But that was only part of the story. The skeleton of the Venus flower basket has a mysterious feature. Ridges of silica glass wind up the outside of the sponge like a spiral staircase or a helix. When Sauro’s team added these ridges to their model, the water inside the hollow cylinder of the sponge started to spiral up and down, flowing in a helix itself.
Interviewee: Sauro Succi
Like a screw, and that’s a very beautiful and sophisticated mechanism.
Interviewer: Ali Jennings
Sauro thinks that the helix of water created within the sponge could help trap and filter particles out of the water, like food, or sperm for sexual preproduction. This could be an adaptation to help these animals survive in the harsh environments of the abyssal plain. I asked Sauro how he felt when he first saw this unexpected result.
Interviewee: Sauro Succi
Ali, I mean, do I have to tell you? Come on. We were elated. You’re just grateful and you feel emotion that you have some beauty in front of you and you feel just happy.
Interviewee: Laura Miller
So, I was really quite impressed with the scale of the simulation and the complexity of the geometry they were able to look at.
Interviewer: Ali Jennings
This is Laura Miller, a mathematician and biologist from the University of Arizona, who was not involved in the research.
Interviewee: Laura Miller
Seeing someone combine these really state-of-the-art computing facilities to answer these questions was really quite exciting.
Interviewer: Ali Jennings
Laura thinks Sauro’s findings will contribute to our understanding of how organisms filter out particles, from water like the sponge but also from the air as trees do with pollen. But now, Laura thinks that there are some important next steps for Sauro to take.
Interviewee: Laura Miller
The authors speculate that the vortical patterns that are set up within the sponge can help with feeding and then also collecting sperm for reproduction, and they’re basically making that assessment just looking at the flow patterns, so it would be interesting to know – given what the sponges feed upon and then also given the size and the properties of the sperm – are they preferentially filtering those out, and sort of how effective is this fluid design in terms of doing that.
Interviewer: Ali Jennings
Laura also points out that one small detail has been missed from Sauro’s model. Lining the inside of the Venus flower basket are cells with flagella – long, whip-like structures that beat the water around them. These flagella could affect the movement of the water as well, but it turns out that Laura and Sauro have been thinking along the same lines.
Interviewee: Sauro Succi
We were able to go to the micrometre, okay. That’s the scale we can resolve. I think the flagella should be in that scale. But if we want to resolve the flagella, then we have to be at least ten times more powerful. And there is a machine in Italy being available probably in a year from now called Leonardo, like Da Vinci, and that’s exactly our target. So, stay tuned because that may be actually the direction to go.
Interviewer: Ali Jennings
Both Laura and Sauro think the design of the Venus flower basket could inspire engineers, perhaps to improve ventilation in buildings or reduce drag in ships, or maybe something even further.
Interviewee: Sauro Succi
There might be some lesson that we can export to totally different scales – buildings or maybe skyscrapers – so design microscopic structures on the lessons learnt from the living cylinder. That would be fantastic.
Interviewer: Ali Jennings
A skyscraper inspired by a deep-sea sponge that knows only the darkness of the abyssal seafloor. Now, that really would be fantastic.
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Host: Shamini Bundell
That was Ali Jennings who spoke to Sauro Succi from the Italian Institute of Technology in Italy and Laura Miller from the University of Arizona in the US. For more on this story, check out Sauro’s paper and a News and Views article written by Laura in the show notes.
Host: Benjamin Thompson
Finally on the show, it’s time for the Briefing chat, where we talk about some of the latest stories that have been highlighted in the Nature Briefing. And Shamini, what have you been reading this week?
Host: Shamini Bundell
So, there was an article in Nature this week about the use of monkeys for research, focused on the US, and how there’s been a massive shortage of primates in general available for research.
Host: Benjamin Thompson
Right, and what’s been causing this shortage then, Shamini? I think I’ve got a fair idea but am I right?
Host: Shamini Bundell
So, as a result of COVID, a lot of primate research centres had to do some emergency prioritising, working out who needs monkeys for vaccine and treatment testing without losing the ongoing research projects for other diseases that also need those animals. However, it seems that actually there’s been a shortage from even before COVID, which is why the government were already pushing some extra money in, and then with COVID as well there was some sort of emergency funding that went in. And yeah, overall, the government has been investing a large amount into sort of redoing all these facilities and expanding them to allow them to house more animals.
Host: Benjamin Thompson
So, this investment then from the US government isn’t necessarily just about breeding more animals?
Host: Shamini Bundell
Well, the aim for research is to have a larger population, and there are a lot of monkeys that are needed. In 2019, about 68,000 non-human primates were used in research, so a lot of the money is in to expanding the centres so that they can house more. In particular, they want to focus on sort of outdoor enclosures which are supposed to be better for the animals and are also cheaper. But also, some of them are needed to make sure they have increased biosafety for monkeys, specifically with SARS-CoV-2. But overall, it seems that certainly the researchers in this field say that a lot more investment is needed.
Host: Benjamin Thompson
Well, let’s get a sense then, Shamini, of what sorts of levels of investment we’re talking.
Host: Shamini Bundell
Over the last couple of years, so this I think includes both the increase in funding from the National Institutes of Health before the pandemic and during the pandemic, has been US$ 29 million, and the current administration is proposing even more for 2022 that needs approving by Congress – another 27% increase so another US$30 million. But one of the people interviewed in this article said that in order to sort of fully reset, revamp the current setups at all of primate research centres across the country would require a one-time sum of US$50 million, which is even more ambitious than what Biden’s administration is proposing.
Host: Benjamin Thompson
And do we have a sense of really how important non-human primate research has been during the pandemic, for example, and more broadly?
Host: Shamini Bundell
Yeah, well, the pandemic, I guess, has really shed a light on it in a way that affects everyone because it’s been absolutely critical in the early testing of vaccines and therapeutics. Obviously there’s a lot of people who disagree fundamentally with this point, and that has caused problems as well for researchers who do want to use macaques and things in their research. For example, a lot of airlines in the US won’t carry primates for research due to pressure from animal rights groups, and there’s been a push from various sorts of universities and companies trying to get the Department for Transportation to order airlines to carry the animals. Another issue that’s come up during the pandemic is that another kind of macaque that’s used for a lot of drug testing was being imported from China and China stopped shipping them because of the pandemic, so there’s been a sort of shortage across the board there.
Host: Benjamin Thompson
Well, maybe finally on this one then, Shamini, presumably the funding is being discussed and we can’t expect all these new facilities to be built tomorrow.
Host: Shamini Bundell
No, and even if they were built tomorrow it takes time to set up the colonies and breed the monkeys. But I think researchers are thinking about sort of futureproofing the system against potentially the next pandemic, and they want to be ready a few years down the line so that they’re not faced with these shortages again.
Host: Benjamin Thompson
Well, my story this week is also looking to the future and I read it on the BBC News website, and this is actually about the European Union, who have just announced a raft of climate change proposals to help get to the bloc’s aim of being carbon neutral by 2050.
Host: Shamini Bundell
Okay, yeah, that’s some important future planning there. So, what does the EU say it needs to do in order to get carbon neutral?
Host: Benjamin Thompson
Well, these proposals are called ‘Fit for 55’ and this is because they put the bloc on course to meet its 2030 goal of reducing emissions by 55% from 1990 levels, and that’s en route to the 2050 carbon neutrality. And so, yeah, lots of discussions have been going on and there’s kind of a dozen or so proposals that have been put forward.
Host: Shamini Bundell
So, that’s like potentially a really ambitious reduction. What’s actually on the table?
Host: Benjamin Thompson
Well, yeah, ‘ambitious’, I think, Shamini, is the right word. The sense that I get is the aim is to try and make polluting more expensive and greener options more attractive. And some of the proposals that have been highlighted are tighter emission levels for cars, which is expected to maybe effectively end sales of new petrol and diesel cars by 2035, a tax on aviation fuel, targets for expanding renewables, requirements that countries quickly renovate buildings that are not energy-efficient, and this thing that’s being called the carbon border tariff that means that manufacturers from outside the EU will need to pay a tariff on the carbon dioxide they emit when selling some things to the EU like steel and concrete and what have you. So, there’s a lot going on there.
Host: Shamini Bundell
Has everyone agreed with this? Is it all systems go?
Host: Benjamin Thompson
Sadly not, Shamini. Even getting to this point, from what I’ve read, was difficult. So, the European Commission, which is the administrative arm of the European Union, apparently there was a lot of disagreements in terms of getting these proposals ready ahead of time and these were announced last week. And there’s been a lot of pushback from industry and there’s been a lot of environmental groups saying these don’t go far enough, and some countries are saying, ‘Hey, this is going to mean that our citizens’ fuel bills are going to go up,’ so there’s been some pushback there. And all 27 members of the EU and the EU parliament need to agree on these so it could be months or even maybe a couple of years before these sort of proposals are actually in place and ready to go, I guess.
Host: Shamini Bundell
And so, some people think this is going way too far, we can’t possibly do this, and other people think this is nowhere near far enough.
Host: Benjamin Thompson
Absolutely, and people are saying that the success of this is going to come down to treading a fine line between what’s considered realistic and fair for society and what doesn’t necessarily disturb the economy of these countries, of this bloc, too much. So, a really, really difficult one, and tough targets but, of course, if countries are going to meet the Paris climate agreement to limit warming to below 2°C, tough targets are really what’s needed and really, really soon.
Host: Shamini Bundell
Well, hopefully we’ll be bringing everyone some more updates in future podcasts on how that’s going. And listeners, another great place for science updates is the Nature Briefing. We’ll put a link in the show notes where you can sign up for those emails, plus links to the stories we’ve discussed today.
Host: Benjamin Thompson
That’s all we’ve got time for this week. But as always, you can reach out to us on email – we’re podcast@nature.com – or on Twitter – we’re @NaturePodcast. I’m Benjamin Thompson.
Host: Shamini Bundell
And I’m Shamini Bundell. Thanks for listening.