Distant galaxies and the true nature of dark matter

At the centre of spiral galaxies -- those near to us but also those billions of light-years away -- there is a vast spherical region made up of dark matter particles. This region has two defining characteristics: a density that is constant out to a certain radius that amazingly expands over time, while the density decreases. This suggests the existence of a direct interaction between the elementary particles that make up the dark matter halo and those that make up ordinary matter -- protons, electrons, neutrons, and photons. We anticipate that this hypothesis is in direct conflict with the current prevailing theory used to describe the universe -- known as Lambda-Cold Dark Matter -- which posits that particles of cold dark matter are inert and do not interact with any other particle except gravitationally.

These important findings have been reported in a new study, recently published in the prestigious Astronomy and Astrophysics journal, that studied a large number of distant galaxies, some seven billion light-years away. The study, conducted by Gauri Sharma and Paolo Salucci from SISSA, together with Glen Van de Ven from the University of Vienna, took a new look at one of the greatest mysteries of modern physics. According to the authors, this new research represents a step forward in our understanding of dark matter, the elusive element in our universe which has been theorised based on its demonstrable effects on heavenly bodies, but which is yet to be directly proven. This is despite any number of targeted astrophysical observations and experiments set up for the purpose in dedicated underground laboratories.

Studying dark matter in distant galaxies

Dark matter makes up approximately 84% of the mass in the cosmos: "Its dominant presence throughout the galaxies arises from the fact that the stars and hydrogen gas are moving as if governed by an invisible element" explains Gauri Sharma. Up until now, attempts to study it have focused on galaxies near to our own: "In this study, however," she explains, "for the first time, we were seeking to observe and determine the distribution of the mass of spiral galaxies with the same morphology of those nearby, but much further away and therefore earlier by some seven billion years. The idea is essentially that these progenitors of spiral galaxies like our own could offer fundamental clues into the nature of the particle at the heart of the mystery of dark matter." Paolo Salucci adds: "By studying the movement of stars in approximately 300 distant galaxies, we discovered that these objects also had a halo of dark matter, and that, by starting out from the centre of a galaxy, this halo effectively has a region in which its density is constant." This trait had already been observed in studies examining nearby galaxies, some of which were also the work of SISSA.

The new research has revealed, however, that this central region had something that was wholly unexpected within the context of the so-called "standard model of cosmology." Sharma says that "as a result of the contrast between the properties of nearby and distant spiral galaxies -- that is, between today's galaxies and their forebears from seven billion years earlier, we could see that not only is there an unexplained region with a constant density of dark matter, but also that its dimensions increase over time as if being subjected to a process of ongoing expansion and dilution." This evidence is very difficult to be explained if the dark matter particles did not interact, as posited in the Lambda-CDM model. "In the research we recently published," says Sharma, "we offer evidence of direct interaction between dark matter and ordinary matter, that over time slowly builds up a region of consistent density from the centre of the galaxy outwards." But there's more.

A slow yet inexorable process

"Amazingly, the above region with constant density expands over time. It's a very slow process, but one that is inexorable" states Salucci. One possible explanation? "The simplest is that, in the beginning, when the galaxy was formed, the distribution of dark matter in the spherical halo was as predicted by the Lambda-CDM theory, with a density peak in the centre. Later on, the galactic disc that characterises spiral galaxies is formed, surrounded by a halo of extremely dense dark matter particles. As time passed, the effect of the interaction that we have posited meant that the particles were captured by the stars or expelled into the outer reaches of the galaxy." This process would create a spherical region of consistent density within the dark matter halo, with dimensions that increase proportionately over time and finally reach those of the galactic stellar disc, as described in the article in "Astronomy and Astrophysics." "The results of the study pose important questions for alternative scenarios that describe dark matter particles (aside from Lambda-CDM), such as Warm Dark Matter, Self-Interacting Dark Matter and Ultra Light Dark Matter" says Sharma.

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Calorie restriction trial reveals key factors in extending human health

Decades of research has shown that limits on calorie intake by flies, worms, and mice can enhance life span in laboratory conditions. But whether such calorie restriction can do the same for humans remains unclear. Now a new study led by Yale researchers confirms the health benefits of moderate calorie restrictions in humans -- and identifies a key protein that could be harnessed to extend health in humans.

The findings were published Feb. 10 in Science.

The research was based on results from the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) clinical trial, the first controlled study of calorie restriction in healthy humans. For the trial, researchers first established baseline calorie intake among more than 200 study participants. The researchers then asked a share of those participants to reduce their calorie intake by 14% while the rest continued to eat as usual, and analyzed the long-term health effects of calorie restriction over the next two years.

The overall aim of the clinical trial was to see if calorie restriction is as beneficial for humans as it is for lab animals, said Vishwa Deep Dixit, the Waldemar Von Zedtwitz Professor of Pathology, Immunobiology, and Comparative Medicine, and senior author of the study. And if it is, he said, researchers wanted to better understand what calorie restriction does to the body specifically that leads to improved health.

Since previous research has shown that calorie restriction in mice can increase infections, Dixit also wanted to determine how calorie restriction might be linked to inflammation and the immune response.

"Because we know that chronic low-grade inflammation in humans is a major trigger of many chronic diseases and, therefore, has a negative effect on life span," said Dixit, who is also director of the Yale Center for Research on Aging. "Here we're asking: What is calorie restriction doing to the immune and metabolic systems and if it is indeed beneficial, how can we harness the endogenous pathways that mimic its effects in humans?"

Dixit and his team started by analyzing the thymus, a gland that sits above the heart and produces T cells, a type of white blood cell and an essential part of the immune system. The thymus ages at a faster rate than other organs. By the time healthy adults reach the age of 40, said Dixit, 70% of the thymus is already fatty and nonfunctional. And as it ages, the thymus produces fewer T cells. "As we get older, we begin to feel the absence of new T cells because the ones we have left aren't great at fighting new pathogens," said Dixit. "That's one of the reasons why elderly people are at greater risk for illness."

For the study, the research team used magnetic resonance imaging (MRI) to determine if there were functional differences between the thymus glands of those who were restricting calories and those who were not. They found that the thymus glands in participants with limited calorie intake had less fat and greater functional volume after two years of calorie restriction, meaning they were producing more T cells than they were at the start of the study. But participants who weren't restricting their calories had no change in functional volume.

"The fact that this organ can be rejuvenated is, in my view, stunning because there is very little evidence of that happening in humans," said Dixit. "That this is even possible is very exciting."

With such a dramatic effect on the thymus, Dixit and his colleagues expected to also find effects on the immune cells that the thymus was producing, changes that might underlie the overall benefits of calorie restriction. But when they sequenced the genes in those cells, they found there were no changes in gene expression after two years of calorie restriction.

This observation required the researchers to take a closer look, which revealed a surprising finding: "It turns out that the action was really in the tissue microenvironment not the blood T cells," Dixit said.

Dixit and his team had studied adipose tissue, or body fat, of participants undergoing calorie restriction at three time points: at the beginning of the study, after one year, and after two. Body fat is very important, Dixit said, because it hosts a robust immune system. There are several types of immune cells in fat, and when they are aberrantly activated, they become a source of inflammation, he explained.

"We found remarkable changes in the gene expression of adipose tissue after one year that were sustained through year two," said Dixit. "This revealed some genes that were implicated in extending life in animals but also unique calorie restriction-mimicking targets that may improve metabolic and anti-inflammatory response in humans."

Recognizing this, the researchers then set out to see if any of the genes they identified in their analysis might be driving some of the beneficial effects of calorie restriction. They honed in on the gene for PLA2G7 -- or group VII A platelet activating factor acetylhydrolase -- which was one of the genes significantly inhibited following calorie restriction. PLA2G7 is a protein produced by immune cells known as macrophages.

This change in PLA2G7 gene expression observed in participants who were limiting their calorie intake suggested the protein might be linked to the effects of calorie restriction. To better understand if PLA2G7 caused some of the effects observed with calorie restriction, the researchers also tracked what happened when the protein was reduced in mice in a laboratory experiment.

"We found that reducing PLA2G7 in mice yielded benefits that were similar to what we saw with calorie restriction in humans," said Olga Spadaro, a former research scientist at the Yale School of Medicine and lead author of the study. Specifically, the thymus glands of these mice were functional for a longer time, the mice were protected from diet-induced weight gain, and they were protected from age-related inflammation.

These effects occurred because PLA2G7 targets a specific mechanism of inflammation called the NLRP3 inflammasome, researchers said. Lowering PLA2G7 protected aged mice from inflammation.

"These findings demonstrate that PLA2G7 is one of the drivers of the effects of calorie restriction," said Dixit. "Identifying these drivers helps us understand how the metabolic system and the immune system talk to each other, which can point us to potential targets that can improve immune function, reduce inflammation, and potentially even enhance healthy lifespan."

For instance, it might be possible to manipulate PLA2G7 and get the benefits of calorie restriction without having to actually restrict calories, which can be harmful for some people, he said.

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How life came to Earth

Researchers have discovered a new clue in the search for the origin of life by showing that peptides can form on dust under conditions such as those prevailing in outer space. These molecules, which are one of the basic building blocks of all life, may therefore not have originated on our planet at all, but possibly in cosmic molecular clouds.

Chains of amino acids

All life as we know it consists of the same chemical building blocks. These include peptides, which perform various completely different functions in the body -- transporting substances, accelerating reactions or forming stabilising scaffolds in cells. Peptides consist of individual amino acids arranged in a specific order. The exact order determines a peptide's eventual properties.

How these versatile biomolecules came into being is one of the questions about the origin of life. Amino acids, nucleobases and various sugars found in meteoroids, for example, show that this origin could be extraterrestrial in nature. However, for a peptide to be formed from individual amino acid molecules, very special conditions are required that were previously assumed to be more likely to exist on Earth.

The first step requires water, while for the second step, there must be no water

"Water plays an important role in the conventional way in which peptides are created," says Dr Serge Krasnokutski of the Laboratory Astrophysics and Cluster Physics Group of the Max Planck Institute for Astronomy at the University of Jena. In this process, individual amino acids combine to form a chain. For this to happen, one water molecule must be removed each time. "Our quantum chemical calculations have now shown that the amino acid glycine can be formed through a chemical precursor -- called an amino ketene -- combining with a water molecule. Put simply: in this case, water must be added for the first reaction step, and water must be removed for the second."

With this knowledge, the team led by the physicist Krasnokutski has now been able to demonstrate a reaction pathway that can take place under cosmic conditions and does not require water.

"Instead of taking the chemical detour in which amino acids are formed, we wanted to find out whether amino ketene molecules could not be formed instead and combine directly to form peptides," says Krasnokutski, describing the basic idea behind the work. He adds: "And we did this under the conditions that prevail in cosmic molecular clouds, that is to say on dust particles in a vacuum, where the corresponding chemicals are present in abundance: carbon, ammonia and carbon monoxide."

In an ultra-high vacuum chamber, substrates that serve as a model for the surface of dust particles were brought together with carbon, ammonia and carbon monoxide at about one quadrillionth of normal air pressure and minus 263 degrees Celsius.

"Investigations showed that under these conditions, the peptide polyglycine was formed from the simple chemicals," Krasnokutski says. "These are therefore chains of the very simple amino acid glycine, and we observed different lengths. The longest specimens consisted of eleven units of the amino acid."

In this experiment, the german team was also able to detect the suspected amino ketene. "The fact that the reaction can take place at such low temperatures at all is due to the amino ketene molecules being extremely reactive. They combine with each other in an effective polymerisation. The product of this is polyglycine."

Quantum mechanical tunnelling effect might play a role

"It was nevertheless surprising to us that the polymerisation of amino ketene could happen so easily under such conditions," says Krasnokutski. "This is because an energy barrier actually has to be overcome for this to happen. However, it may be that we are helped in this by a special effect of quantum mechanics. In this special reaction step, a hydrogen atom changes its place. However, it is so small that, as a quantum particle, it could not overcome the barrier but was simply able to cross it, so to speak, through the tunnelling effect."

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Planetary bodies observed for first time in 'habitable zone' of dead star

A ring of planetary debris studded with moon-sized structures has been observed orbiting close to a white dwarf star, hinting at a nearby planet in the "habitable zone" where water and life could exist, according to a new study led by UCL researchers.

White dwarfs are glowing embers of stars that have burned through all their hydrogen fuel. Nearly all stars, including the Sun, will eventually become white dwarfs, but very little is known about their planetary systems.

In the study, published in Monthly Notices of the Royal Astronomical Society, an international team of researchers measured light from a white dwarf in the Milky Way known as WD1054-226, using data from ground- and space-based telescopes.

To their surprise, they found pronounced dips in light corresponding to 65 evenly spaced clouds of planetary debris orbiting the star every 25 hours. The researchers concluded that the precise regularity of the transiting structures -- dimming the star's light every 23 minutes -- suggests they are kept in such a precise arrangement by a nearby planet.

Lead author Professor Jay Farihi (UCL Physics & Astronomy) said: "This is the first time astronomers have detected any kind of planetary body in the habitable zone of a white dwarf.

"The moon-sized structures we have observed are irregular and dusty (e.g. comet-like) rather than solid, spherical bodies. Their absolute regularity, one passing in front of the star every 23 minutes, is a mystery we cannot currently explain.

"An exciting possibility is that these bodies are kept in such an evenly-spaced orbital pattern because of the gravitational influence of a nearby planet. Without this influence, friction and collisions would cause the structures to disperse, losing the precise regularity that is observed. A precedent for this 'shepherding' is the way the gravitational pull of moons around Neptune and Saturn help to create stable ring structures orbiting these planets.

"The possibility of a planet in the habitable zone is exciting and also unexpected; we were not looking for this. However, it is important to keep in mind that more evidence is necessary to confirm the presence of a planet. We cannot observe the planet directly so confirmation may come by comparing computer models with further observations of the star and orbiting debris."

It is expected that this orbit around the white dwarf was swept clear during the giant star phase of its life, and thus any planet that can potentially host water and thus life would be a recent development. The area would be habitable for at least two billion years, including at least one billion years into the future.

More than 95% of all stars will eventually become white dwarfs. The exceptions are the largest stars that explode and become either black holes or neutron stars.

Professor Farihi added: "Since our Sun will become a white dwarf in a few billion years, our study provides a glimpse into the future of our own solar system."

When stars begin running out of hydrogen, they expand and cool, becoming red giants. The Sun will enter this phase in four to five billion years, swallowing Mercury, Venus, and possibly Earth. Once the outer material has gently blown away and hydrogen is exhausted, the hot core of the star remains, slowly cooling over billions of years -- this is the star's white dwarf phase.

Planets orbiting white dwarfs are challenging for astronomers to detect because the stars are much fainter than main-sequence stars (like the Sun). So far, astronomers have only found tentative evidence of a gas giant (like Jupiter) orbiting a white dwarf.

For the new study, researchers observed WD1054-226, a white dwarf 117 light years away, recording changes in its light over 18 nights using the ULTRACAM high-speed camera fixed on to the ESO 3.5m New Technology Telescope (NTT) at the La Silla Observatory in Chile. In order to better interpret the changes in light, the researchers also looked at data from the NASA Transiting Exoplanet Survey Satellite (TESS), which allowed the researchers to confirm the planetary structures had a 25-hour orbit.

They found that the light from WD1054-226 was always somewhat obscured by enormous clouds of orbiting material passing in front of it, suggesting a ring of planetary debris orbiting the star.

The habitable zone, sometimes called the Goldilocks zone, is the area where the temperature would theoretically allow liquid water to exist on the surface of a planet. Compared to a star like the Sun, the habitable zone of a white dwarf will be smaller and closer to the star as white dwarfs give off less light and thus heat.

The structures observed in the study orbit in an area that would have been enveloped by the star while it was a red giant, so are likely to have formed or arrived relatively recently, rather than survived from the birth of the star and its planetary system.

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First evidence indicating dinosaur respiratory infection

A group of researchers from around the country, including University of New Mexico Research Assistant Professor Ewan Wolff, discovered the first evidence of a unique respiratory infection in the fossilized remains of a dinosaur that lived nearly 150 million years ago.

Researchers examined the remains of an immature diplodocid -- a long-necked herbivorous sauropod dinosaur, like "Brontosaurus" - dating back to the Late Jurassic Period of the Mesozoic Era. The dinosaur nicknamed "Dolly," discovered in southwest Montana, had evidence of an infection in the area of its neck vertebrae.

They study, led by Cary Woodruff of the Great Plains Dinosaur Museum, identified never before seen abnormal bony protrusions that had an unusual shape and texture. These protrusions were located in an area of each bone where they would have been penetrated by air sacs. Air sacs are non-oxygen exchanging parts of the respiratory system in modern birds that are also present in dinosaurs. The air sacs would have ultimately connected to "Dolly's" lungs and formed part of the dinosaur's complex respiratory system. CT imaging of the irregular protrusions revealed that they were made of abnormal bone that most likely formed in response to an infection.

"We've all experienced these same symptoms -- coughing, trouble breathing, fever and here's a 150-million-year-old dinosaur that likely felt as miserable as we all do when we're sick." Woodruff said.

Researchers say these findings are significant because Dolly was considered a non-avian dinosaur, and sauropods, like Dolly, did not evolve to become birds; only avian theropods evolved into birds. The authors speculate this respiratory infection could have been caused by a fungal infection similar to aspergillosis, a common respiratory illness that affects birds and reptiles today and can lead to bone infections. In addition to documenting the first occurrence of such a respiratory infection in a dinosaur, this fossilized infection also has important anatomical implications for the respiratory system of sauropod dinosaurs.

"This fossil infection in Dolly not only helps us trace the evolutionary history of respiratory-related diseases back in time, but it also gives us a better understanding of what kinds of diseases dinosaurs were susceptible to," Woodruff said.

"This would have been a remarkably, visibly sick sauropod," Wolff said. "We always think of dinosaurs as big and tough, but they got sick. They had respiratory illnesses like birds do today, in fact, maybe even the same devastating infections in some cases."

The researchers suggest that if Dolly had been infected with an aspergillosis-like respiratory infection, it likely experienced flu or pneumonia-like symptoms such as weight loss, coughing, fever and breathing difficulties. As aspergillosis can be fatal in birds if untreated, a potentially similar infection in Dolly could have ultimately caused the death of the animal.

"We have to continue to expand our knowledge of ancient diseases. If we look hard enough, we may begin to understand more about the evolution of immunity and infectious disease," Wolff said. "When we work together between multiple specialties -- veterinarians, anatomists, paleontologists, paleopathologists, and radiologists we can come away with a more complete picture of ancient disease."

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Futuristic coating for hospital fabrics and activewear kills COVID virus and E. coli

UBC researchers have developed an inexpensive, non-toxic coating for almost any fabric that decreases the infectivity of the virus that causes COVID-19 by up to 90 per cent.

And in the future, you might be able to spray it on fabric yourself.

"When you're walking into a hospital, you want to know that pillow you're putting your head onto is clean," says lead author Taylor Wright, a doctoral student in the department of chemistry. "This coating could take a little bit of the worry off frontline workers to have Personal Protection Equipment with antimicrobial properties."

Researchers soaked fabric in a solution of a bacteria-killing polymer which contains a molecule that releases sterilizing forms of oxygen when light shines on it. They then used an ultraviolet (UV) light to turn this solution to a solid, fixing the coating to the fabric. "This coating has both passive and active antimicrobial properties, killing microbes immediately upon contact, which is then amped up when sunlight hits the cloth," says senior author Dr. Michael Wolf (he/him), a professor of chemistry.

Both components are safe for human use, and the entire process takes about one hour at room temperature, says Wright. It also makes the fabric hydrophobic, meaning microbes are less likely to stick to the cloth, and doesn't seem to affect the strength of the fabric.

In addition, the coating can be used on almost any fabric, including cotton, polyester, denim, and silk, with applications in hospital fabrics, masks, and activewear. Whereas other such technologies can involve chemical waste, high energy use, or expensive equipment, the UBC method is relatively easy and affordable, says Wright. "All we need is a beaker and a light bulb. I'm fairly certain I could do the whole process on a stove."

To test the coating's bug-killing properties, the researchers bathed treated fabric in bacterial soups of Escherichia coli (E. coli) andMethicillin-resistant Staphylococcus aureus (MRSA), both major sources of hospital-acquired infections. They found there were 85 per cent of viable E. coli bacteria remaining after 30 minutes, which fell to three per cent when the treated cloth was exposed to green light for the same amount of time. Similarly, 95 per cent of viable MRSA bacteria remained, dropping to 35 per cent under green light. No bacteria remained after four hours.

Given that sunlight or fluorescent lights have a lesser percentage of green, the team expects similar but less intense results for fabric exposed to those light sources, says Wright. "Particularly in the Pacific Northwest, it's not always a sunny day. So, at all times you're going to have that layer of passive protection and when you need that extra layer of protection, you can step into a lit room, or place the fabric in a room with a green light bulb -- which can be found for about $35 online."

The researchers also looked into whether the coating reduced the infectivity of SARS-CoV-2, the virus causing COVID-19 by bathing treated fabric in a solution of the virus particles and then adding that solution to living cells to see if they could infect them. They found the passive properties weren't effective against the virus, but when treated fabric was exposed to green light for two hours, there was up to 90 per cent decrease in the infectivity of SARS-CoV-2. "In other words, only one tenth of the amount of virus signal was detected on cells infected with the UV-fabric and light treated virus," says co-author Dr. François Jean (he/him), professor of virology at UBC. The efficacy of the new fabric against SARS-CoV-2 was demonstrated by Dr. Jean's team at UBC FINDER, the state-of-the-art level three biocontainment facility founded by Dr. Jean in 2010.

The team found they needed an 18 square centimeter piece of fabric to kill microbes with material containing seven per cent weight of the active ingredient, but that increasing this to 23 per cent weight increased the effectiveness of the fabric at four times less material, says Wright.

Researchers also found that keeping the fabric under green light for more than 24 hours failed to produce the sterilizing forms of oxygen, highlighting an area for further study. This is a similar effect to the color fading on clothing after being exposed to sunlight for too long.

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Reusable plastic bottles release hundreds of chemicals

Researchers at the University of Copenhagen have found several hundred different chemical substances in tap water stored in reusable plastic bottles. Several of these substances are potentially harmful to human health. There is a need for better regulation and manufacturing standards for manufacturers, according to the chemists behind the study.

Have you ever experienced the strange taste of water after it has been in a reusable plastic bottle for a while? It appears that there is a solid, yet worrying reason for this.

Two chemists from the University of Copenhagen have studied which chemical substances are released into liquids by popular types of soft plastic reusable bottles. The results were quite a surprise.

"We were taken aback by the large amount of chemical substances we found in water after 24 hours in the bottles. There were hundreds of substances in the water -- including substances never before found in plastic, as well as substances that are potentially harmful to health. After a dishwasher cycle, there were several thousand," says Jan H. Christensen, Professor of Environmental Analytical Chemistry at the University of Copenhagen's Department of Plant and Environmental Sciences.

Endocrine disruptors and insecticide

Professor Christensen and fellow researcher Selina Tisler detected more than 400 different substances from the bottle plastic and over 3,500 substances derived from dishwasher soap. A large portion of these are unknown substances that the researchers have yet to identify. But even of the identified chemicals, the toxicity of at least 70 % remains unknown.

Photo-initiators are among the toxic substances in the water which worry the researchers. These are known to have potentially harmful effects on health in organisms, such as being endocrine disruptors and carcinogens. Furthermore, the researchers found a variety of plastic softeners, antioxidants and release agents used in the manufacture of the plastic, as well as Diethyltoluamide (DEET), commonly known as the active substance in mosquito spray.

Machine washing adds more substances into the bottled water

In their experiments, the researchers mimicked the ways in which many people typically use plastic drinks bottles. People often drink water that has been kept in bottles for several hours. The researchers left ordinary tap water in both new and used drinking bottles for 24 hours, both before and after machine washing, as well as after the bottles had been in the dishwasher and rinsed thoroughly in tap water.

"What is released most after machine washing are the soap substances from the surface. Most of the chemicals that come from the water bottle itself remain after machine washing and extra rinsing. The most toxic substances that we identified actually came after the bottle had been in the dishwasher -- presumably because washing wears down the plastic and thereby increases leaching," explains postdoctoral researcher and first author Selina Tisler of the Department of Plant and Environmental Sciences.

In new reusable bottles, close to 500 different substances remained in the water after an additional rinse. Over 100 of these substances came from the plastic itself.

She emphasizes that they have yet to conclude whether the water in the bottles is harmful to health, as they currently have only an estimate of the concentrations of the substances and toxicological assessments have yet to be completed.

'Just because these substances are in the water, doesn't mean that the water is toxic and affects us humans. But the problem is, is that we just don't know. And in principle, it isn't all that great to be drinking soap residues or other chemicals," says Selina Tisler.

"From now on, I'll use a glass bottle."

"We care so much about low levels of pesticides in our drinking water. But when we pour water into a container to drink from, we unflinchingly add hundreds or thousands of substances to the water ourselves. Although we cannot yet say whether the substances in the reusable bottles affect our health, I'll be using a glass or quality stainless steel bottle in the future," says Jan H. Christensen.

The researchers suspect that bottle manufacturers only add a small proportion of the substances found intentionally. The majority have inadvertently occurred either during the production process or during use, where substances may have been converted from other substances. This includes the presence of the mosquito repellent DEET, where the researchers hypothesize that as one of the plastic softeners degrades, it is converted into DEET.

"But even of the known substances that manufacturers deliberately add, only a tiny fraction of the toxicity has been studied. So, as a consumer, you don't know if any of the others have a detrimental effect on your health," says Selina Tisler.

Too little knowledge, too leniently regulated

According to the researchers, the results reflect a lack of both knowledge and regulation:

"The study exemplifies how little knowledge there is about the chemicals emitted from the products that our food and drink come in contact with. And, it is a general problem that measurement regulations during production are very lenient. Fortunately, both in Denmark and internationally, we are looking into how to better regulate this area," says Jan H. Christensen.

In the meantime, Selina Tisler hopes that companies take responsibility on their own accord:

"Hopefully, companies that put their names on reusable plastic bottles will be more careful about the products they purchase from suppliers and perhaps place greater demands on suppliers to investigate the substances found in what they manufacture," Tisler concludes.

The study results are published in the scientific journal Journal of Hazardous Materials.

Brief summary of experiment

Three different types of drinking bottles were tested, all of which are found in Danish stores. Two of the bottles are made of biodegradable plastic, according to the manufacturer. Both new and heavily used bottles were used. The bottles were tested both before and after machine washing, and after five extra rinses in tap water.

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New planet detected around Proxima Centauri, closest star our solar system

A team of astronomers using the European Southern Observatory's Very Large Telescope (ESO's VLT) in Chile have found evidence of another planet orbiting Proxima Centauri, the closest star to our Solar System. This candidate planet is the third detected in the system and the lightest yet discovered orbiting this star. At just a quarter of Earth's mass, the planet is also one of the lightest exoplanets ever found.

"The discovery shows that our closest stellar neighbour seems to be packed with interesting new worlds, within reach of further study and future exploration," explains João Faria, a researcher at the Instituto de Astrofísica e Ciências do Espaço, Portugal and lead author of the study published today in Astronomy & Astrophysics. Proxima Centauri is the closest star to the Sun, lying just over four light-years away.

The newly discovered planet, named Proxima d, orbits Proxima Centauri at a distance of about four million kilometres, less than a tenth of Mercury's distance from the Sun. It orbits between the star and the habitable zone -- the area around a star where liquid water can exist at the surface of a planet -- and takes just five days to complete one orbit around Proxima Centauri.

The star is already known to host two other planets: Proxima b, a planet with a mass comparable to that of Earth that orbits the star every 11 days and is within the habitable zone, and candidate Proxima c, which is on a longer five-year orbit around the star.

Proxima b was discovered a few years ago using the HARPS instrument on ESO's 3.6-metre telescope. The discovery was confirmed in 2020 when scientists observed the Proxima system with a new instrument on ESO's VLT that had greater precision, the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO). It was during these more recent VLT observations that astronomers spotted the first hints of a signal corresponding to an object with a five-day orbit. As the signal was so weak, the team had to conduct follow-up observations with ESPRESSO to confirm that it was due to a planet, and not simply a result of changes in the star itself.

"After obtaining new observations, we were able to confirm this signal as a new planet candidate," Faria says. "I was excited by the challenge of detecting such a small signal and, by doing so, discovering an exoplanet so close to Earth."

At just a quarter of the mass of Earth, Proxima d is the lightest exoplanet ever measured using the radial velocity technique, surpassing a planet recently discovered in the L 98-59 planetary system. The technique works by picking up tiny wobbles in the motion of a star created by an orbiting planet's gravitational pull. The effect of Proxima d's gravity is so small that it only causes Proxima Centauri to move back and forth at around 40 centimetres per second (1.44 kilometres per hour).

"This achievement is extremely important," says Pedro Figueira, ESPRESSO instrument scientist at ESO in Chile. "It shows that the radial velocity technique has the potential to unveil a population of light planets, like our own, that are expected to be the most abundant in our galaxy and that can potentially host life as we know it."

"This result clearly shows what ESPRESSO is capable of and makes me wonder about what it will be able to find in the future," Faria adds.

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JET fusion facility sets a new world energy record

European scientists have achieved a major success on the road to energy production through fusion plasmas: They produced stable plasmas with 59 megajoules of energy output at the world's largest fusion facility, JET, in Culham near Oxford, UK. The team, which also includes researchers from the Max Planck Institute for Plasma Physics (IPP), used the fuel of future fusion power plants. These were the first experiments of their kind in the world in more than 20 years.

Following the example of the sun, fusion power plants aim to fuse the hydrogen isotopes deuterium and tritium and release large amounts of energy in the process. The only plant in the world currently capable of operating with such fuel is the European joint project JET, the Joint European Torus in Culham near Oxford, UK. However, the last experiments with the fuel for future fusion power plants were conducted there in 1997. Because tritium is a very rare raw material that also poses special handling challenges, research teams usually use hydrogen or deuterium for plasma experiments. In future power plants, tritium will be formed from lithium during energy production.

Experiments with deuterium-tritium mixtures in preparation for ITER

"We can explore the physics in fusion plasmas very well by working with hydrogen or deuterium, so this is the standard worldwide," explains IPP's Dr. Athina Kappatou, who with her IPP colleagues Dr. Philip Schneider and Dr. Jörg Hobirk led significant parts of the European collaborative experiments at JET." However, for the transition to the international, large-scale, fusion experiment ITER, it is important that we prepare for the conditions prevailing there." ITER is currently under construction in Cadarache, in southern France, and is expected to be able to release ten times as much energy as is fed into the plasma in terms of heating energy, using deuterium-tritium fuel.

To bring the JET experiment as close as possible to future ITER conditions, the previous carbon lining of the plasma vessel was replaced by a mixture of beryllium and tungsten, as is also planned for ITER, between 2009 and 2011. The metal tungsten is more resistant than carbon, which, moreover, stores too much hydrogen. However, the now metallic wall places new demands on the quality of the plasma control. The current experiments demonstrate the successes of the researchers: At temperatures ten times higher than those at the center of the sun, record levels of generated fusion energy have been achieved.

World record under ITER-like conditions

Prior to the change of the wall material, JET had set the world energy record in 1997 with a plasma that produced 22 megajoules of energy. This record stood until now. "In the latest experiments, we wanted to prove that we could create significantly more energy even under ITER-like conditions," explains IPP physicist Dr. Kappatou. Several hundred scientists and researchers were involved in years of preparation for the experiments. They used theoretical methods to calculate in advance the parameters they needed to obtain to generate the plasma in order to achieve their goals. The experiments confirmed the predictions in late 2021 and delivered a new world record: JET produced stable plasmas with deuterium-tritium fuel that released 59 megajoules of energy.

To produce net energy -- that is, to release more energy than the heatering systems provide -- the experimental facility is too small. This will not be possible until the larger-scale ITER experiment in southern France comes online. "The latest experiments at JET are an important step toward ITER," concludes Prof. Sibylle Günter, Scientific Director of the Max Planck Institute for Plasma Physics. "What we have learned in the past months will make it easier for us to plan experiments with fusion plasmas that generate much more energy than is needed to heat them."

Background information: Megawatts vs. Megajoules

In the recent record-breaking experiment, the fusion reactions in JET released a total of 59 megajoules of energy in the form of neutrons during a five-second phase of a plasma discharge. Expressed in units of power (energy per time), JET achieved a power output of just over 11 megawatts averaged over five seconds. The previous energy record, set in 1997, was just under 22 megajoules of total energy and 4.4 megawatts of power averaged over five seconds.

About JET

JET was jointly designed and built by the members of the European fusion program EUROfusion and has been jointly operated since 1983. The English fusion center "Culham Centre for Fusion Energy" in Culham near Oxford is responsible for the technical operations, while temporarily seconded researchers and technicians from the EUROfusion laboratories work on the facility on a campaign basis. With numerous secondments, IPP is an important participant in the JET program.

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Co-occurring droughts could threaten global food security

Droughts occurring at the same time across different regions of the planet could place an unprecedented strain on the global agricultural system and threaten the water security of millions of people, according to a new study in Nature Climate Change.

A Washington State University-led research team analyzed climate, agricultural and population growth data to show continuing fossil fuel dependence will increase the probability of co-occurring droughts 40% by the mid-21st century and 60% by the late 21st century, relative to the late-20th century. That comes out to an approximately ninefold increase in agricultural and human population exposure to severe co-occurring droughts unless steps are taken to lower carbon emissions.

"There could be around 120 million people across the globe simultaneously exposed to severe compound droughts each year by the end of the century," said lead author Jitendra Singh, a former postdoctoral researcher at the WSU School of the Environment now at ETH Zurich, Switzerland. "Many of the regions our analysis shows will be most affected are already vulnerable and so the potential for droughts to become disasters is high."

The elevated risk of compound droughts estimated by Singh and colleagues is a result of a warming climate coupled with a projected 22% increase in the frequency of El Niño and La Niña events, the two opposite phases of the El Niño Southern Oscillation (ENSO).

The researchers' projections show that nearly 75% of compound droughts in the future will coincide with these irregular but recurring periods of climatic variation in the world's oceans, which have played a large role in some of the greatest environmental disasters in world history.

For example, El Nino-fueled droughts that concurrently occurred across Asia, Brazil and Africa during 1876-1878 led to synchronous crop failures, followed by famines that killed more than 50 million people.

"While technology and other circumstances today are a lot different than they were in the late 19th century, crop failures in multiple breadbasket regions still have the potential to affect global food availability," said study coauthor Deepti Singh, an assistant professor in the WSU School of the Environment. "This could in turn increase volatility in global food prices, affecting food access and exacerbating food insecurity, particularly in regions that are already vulnerable to environmental shocks such as droughts."

The researchers' analysis specifically focused on ten regions of the planet that receive most of their rainfall during June-September, have high variability in monthly summer precipitation and are affected by ENSO variations, factors that lead to an increased potential for co-occurring drought. Several of the regions analyzed include important agricultural regions and countries that are currently facing food and water insecurity.

Their results indicate areas of North and South America are more likely to experience compound droughts in a future, warmer climate than regions of Asia, where much of the agricultural land is projected to become wetter.

Food produced in the Americas could therefore be more susceptible to climatic hazards. For instance, the United States is a major exporter of staple grains and currently ships maize to countries across the globe. Even a modest increase in the risk of compound droughts in the future climate could lead to regional supply shortfalls that could in turn cascade into the global market, affecting global prices and amplifying food insecurity.

"The potential for a food security crisis increases even if these droughts aren't affecting major food producing regions but rather many regions that are already vulnerable to food insecurity," said coauthor Weston Anderson, an assistant research scientist at the Earth System Science Interdisciplinary Center at the University of Maryland. "Simultaneous droughts in food insecure regions could in turn amplify stresses on international agencies responsible for disaster relief by requiring the provision of humanitarian aid to a greater number of people simultaneously."

There is some good news, Anderson said. The researchers' work is based on a high fossil fuel emissions scenario, and in recent years, the global community has made progress toward lowering carbon emissions which would greatly mitigate the frequency and intensity of co-occurring droughts by the end of the 21st century.

Also, the occurrence of nearly 75% of compound droughts alongside ENSO events in the future climate highlights the potential to predict where these droughts may occur with a lead time of up to nine months.

"This means that co-occurring droughts during ENSO events will likely affect the same geographical regions they do today albeit with greater severity," said Deepti Singh. "Being able to predict where these droughts will occur and their potential impacts can help society develop plans and efforts to minimize economic losses and reduce human suffering from such climate-driven disasters."

Moving forward the researchers plan to take a closer look at how co-occurring droughts will affect various aspects of the global food network, how vulnerable communities are affected by and adapting to such climate extremes, as well as how society can be better prepared to manage the risk of increasing simultaneous disasters.

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In a first for 'sonogenetics,' researchers control mammalian cells with sound

Salk scientists have engineered mammalian cells to be activated using ultrasound. The method, which the team used to activate human cells in a dish and brain cells inside living mice, paves the way toward non-invasive versions of deep brain stimulation, pacemakers and insulin pumps. The findings were published in Nature Communications on February 9, 2022.

"Going wireless is the future for just about everything," says senior author Sreekanth Chalasani, an associate professor in Salk's Molecular Neurobiology Laboratory. "We already know that ultrasound is safe, and that it can go through bone, muscle and other tissues, making it the ultimate tool for manipulating cells deep in the body."

About a decade ago, Chalasani pioneered the idea of using ultrasonic waves to stimulate specific groups of genetically marked cells, and coined the term "sonogenetics" to describe it. In 2015, his group showed that, in the roundworm Caenorhabditis elegans, a protein called TRP-4 makes cells sensitive to low-frequency ultrasound. When the researchers added TRP-4 to C. elegans neurons that didn't usually have it, they could activate these cells with a burst of ultrasound -- the same sound waves used in medical sonograms.

When the researchers tried adding TRP-4 to mammalian cells, however, the protein was not able to make the cells respond to ultrasound. A few mammalian proteins were reported to be ultrasound-sensitive, but none seemed ideal for clinical use. So Chalasani and his colleagues set out to search for a new mammalian protein that made cells highly ultrasound sensitive at 7 MHz, considered an optimal and safe frequency.

"Our approach was different than previous screens because we set out to look for ultrasound-sensitive channels in a comprehensive way," says Yusuf Tufail, a former project scientist at Salk and a co-first author of the new paper.

The researchers added hundreds of different proteins, one at a time, to a common human research cell line (HEK), which does not usually respond to ultrasound. Then, they put each cell culture under a setup that let them monitor changes to the cells upon ultrasound stimulation.

After screening proteins for more than a year, and working their way through nearly 300 candidates, the scientists finally found one that made the HEK cells sensitive to the 7 MHz ultrasound frequency. TRPA1, a channel protein, was known to let cells respond to the presence of noxious compounds and to activate a range of cells in the human body, including brain and heart cells.

But Chalasani's team discovered that the channel also opened in response to ultrasound in HEK cells.

"We were really surprised," says co-first author of the paper Marc Duque, a Salk exchange student. "TRPA1 has been well-studied in the literature but hasn't been described as a classical mechanosensitive protein that you'd expect to respond to ultrasound."

To test whether the channel could activate other cell types in response to ultrasound, the team used a gene therapy approach to add the genes for human TRPA1 to a specific group of neurons in the brains of living mice. When they then administered ultrasound to the mice, only the neurons with the TRPA1 genes were activated.

Clinicians treating conditions including Parkinson's disease and epilepsy currently use deep brain stimulation, which involves surgically implanting electrodes in the brain, to activate certain subsets of neurons. Chalasani says that sonogenetics could one day replace this approach -- the next step would be developing a gene therapy delivery method that can cross the blood-brain barrier, something that is already being studied.

Perhaps sooner, he says, sonogenetics could be used to activate cells in the heart, as a kind of pacemaker that requires no implantation. "Gene delivery techniques already exist for getting a new gene -- such as TRPA1 -- into the human heart," Chalasani says. "If we can then use an external ultrasound device to activate those cells, that could really revolutionize pacemakers."

For now, his team is carrying out more basic work on exactly how TRPA1 senses ultrasound. "In order to make this finding more useful for future research and clinical applications, we hope to determine exactly what parts of TRPA1 contribute to its ultrasound sensitivity and tweak them to enhance this sensitivity," says Corinne Lee-Kubli, a co-first author of the paper and former postdoctoral fellow at Salk.

They also plan to carry out another screen for ultrasound sensitive proteins -- this time looking for proteins that can inhibit, or shut off, a cell's activity in response to ultrasound.

Read more at Science Daily

Predicting the efficiency of oxygen-evolving electrolysis on the Moon and Mars

Scientists at The University of Manchester and The University of Glasgow have today provided more insight into the possibility of establishing a pathway to generate oxygen for humans to potentially call the Moon or Mars 'home' for extended periods of time.

Creating a reliable source of oxygen could help humanity establish liveable habitats off-Earth in an era where space travel is more achievable than ever before. Electrolysis is a popular potential method which involves passing electricity through a chemical system to drive a reaction and can be used to extract oxygen out of lunar rocks or to split water into hydrogen and oxygen. This can be useful for both life support systems as well as for the in-situ production of rocket propellant.

Until now however, how lower gravitational fields on the Moon (1/6th of Earth's gravity) and Mars (1/3rd of Earth's gravity) might affect gas-evolving electrolysis when compared to known conditions here on Earth had not been investigated in detail. Lower gravity can have a significant impact on electrolysis efficiency, as bubbles can remain stuck to electrode surfaces and create a resistive layer.

New research published today in Nature Communications demonstrates how a team of researchers from The University of Manchester and the University of Glasgow undertook experiments to determine how the potentially life-giving electrolysis method acted in reduced gravity conditions.

Lead engineer of the project, Gunter Just, said: "We designed and built a small centrifuge that could generate a range of gravity levels relevant to the Moon and Mars, and operated it during microgravity on a parabolic flight, to remove the influence of Earth's gravity.

"When doing an experiment in the lab, you cannot escape the gravity of Earth; in the almost zero-g background in the aircraft, however, our electrolysis cells were only influenced by the centrifugal force and so we could tune the gravity-level of each experiment by changing the rotation speed. The centrifuge had four 25 cm arms that each held an electrolysis cell equipped with a variety of sensors, so during each parabola of around 18 seconds we did four simultaneous experiments on the spinning system.

"We also operated the same experiments on the centrifuge between 1 and 8 g in the laboratory. In this configuration we had the arms swinging so that the downwards gravity was accounted for.It was found that the trend observed below 1 g was consistent with the trend above 1 g, which experimentally verified that high gravity platforms can be used to predict electrolysis behaviour in lunar gravity, removing the limitations of needing costly and complex microgravity conditions. In our system, we found that 11% less oxygen was produced in lunar gravity, if the same operating parameters were used as on Earth."

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How Mars lost its oceans

It has long been known that Mars once had oceans due in part to a protective magnetic field similar to Earth's. However, the magnetic field disappeared, and new research may finally be able to explain why. Researchers recreated conditions expected in the core of Mars billions of years ago and found that the behavior of the molten metal thought to be present likely gave rise to a brief magnetic field that was destined to fade away.

Whether it's due to science fiction or the fact that you can see it with your own eyes from Earth, Mars has captured the imagination of people for centuries. It's one of the closest planets to us and has been studied with all manner of scientific instruments aboard the various unmanned space probes that have explored it and continue to do so. Yet, despite this, there are some big unanswered questions about Mars -- the answers to which could even shed light on our own distant past and future, given that Earth, Mars and all our neighboring planets were born of the same cosmic stuff.

Some big questions about Mars have already been answered. For example, we know that many visible features of Mars are proof it used to have oceans and a protective magnetic field. But one question in particular had been on the mind of Professor Kei Hirose from the University of Tokyo's Department of Earth and Planetary Science: There must have been a magnetic field around Mars, so why was it there at all, and why was it there so briefly? Compelled to answer this question, a team led by Ph.D. student Shunpei Yokoo in the Hirose lab explored a novel way to test something so distant from us in both time and space.

"Earth's magnetic field is driven by inconceivably huge convection currents of molten metals in its core. Magnetic fields on other planets are thought to work the same way," said Hirose. "Though the internal composition of Mars is not yet known, evidence from meteorites suggests it is molten iron enriched with sulphur. Furthermore, seismic readings from NASA's InSight probe on the surface tell us Mars' core is larger and less dense than previously thought. These things imply the presence of additional lighter elements such as hydrogen. With this detail, we prepare iron alloys that we expect constitute the core and subject them to experiments."

The experiment involved diamonds, lasers, and an unexpected surprise. Yokoo made a sample of material containing iron, sulphur and hydrogen, Fe-S-H, which is what he and his team expect the core of Mars was once made from. They placed this sample between two diamonds and compressed it while heating it with an infrared laser. This was to simulate the estimated temperature and pressure at the core. Sample observations with X-ray and electron beams allowed the team to image what was going on during melting under pressure, and even map how the composition of the sample changed during that time.

"We were very surprised to see a particular behavior that could explain a lot. The initially homogeneous Fe-S-H separated out into two distinct liquids with a level of complexity that has not been seen before under these kinds of pressures," said Hirose. "One of the iron liquids was rich in sulphur, the other rich in hydrogen, and this is key to explaining the birth and eventually death of the magnetic field around Mars."

The liquid iron rich in hydrogen and poor in sulphur, being less dense, would have risen above the denser sulphur-rich, hydrogen-poor liquid iron, causing convection currents. These currents, similar to those on Earth, would have driven a magnetic field capable of maintaining hydrogen in an atmosphere around Mars, which in turn would have allowed water to exist as a liquid. However, it was not to last. Unlike the Earth's internal convection currents which are extremely long lasting, once the two liquids had fully separated, there would have been no more currents to drive a magnetic field. And when that happened, hydrogen in the atmosphere was blown out to space by solar wind, leading to the breakdown of water vapor and eventually the evaporation of the Martian oceans. And this would all have taken place about 4 billion years ago.

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Monkeys, like people, can 'choke under pressure'

Being stressed about doing well on a test might not be limited to humans, according to a new study led by researchers at Georgia State University.

Researchers say the study, which involved tufted capuchin monkeys living in groups at Georgia State's Language Research Center, is the first to specifically explore whether other species experience pressure to perform.

The monkeys were given a computerized matching task. Some trials were cued to be harder, with a higher possible reward and a timeout consequence for wrong answers, while other trials were typical in difficulty to their usual computer tasks.

The team found that there was significant variation in how individual monkeys responded to these trials when the difference in difficulty was removed, suggesting that for some monkeys the cues of high stakes were enough to impact performance.

"There are several different explanations for why humans might 'choke' or 'thrive' under pressure, but all of these explanations have traditionally considered this sensitivity to pressure to be a human-specific trait," said the study's lead author, Georgia State Ph.D. candidate Meg Sosnowski.

"Our new results provide the first evidence that other species also might be susceptible to this influence of pressure, and that our responses to that pressure are, in part, the result of individual variation in an evolutionarily common stress response."

The researchers also found that higher levels of a naturally occurring biomarker of stress, cortisol, were related to the monkeys' performance. Higher levels of cortisol were associated with a lower ability to successfully complete the high-pressure trials, providing evidence that an individual's long-term stress state might be related to cognitive performance.

"This opens the door not just to explore how responses to pressure might have impacted the evolution of cognition, but also provides clues pointing us to potential avenues that might mitigate performance deficits, both in humans and in other species," Sosnowski said.

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Researchers confirm newly developed inhaled vaccine delivers broad protection against SARS-CoV-2, variants of concern

Scientists at McMaster University who have developed an inhaled form of COVID vaccine have confirmed it can provide broad, long-lasting protection against the original strain of SARS-CoV-2 and variants of concern.

The research, recently published in the journal Cell, reveals the immune mechanisms and significant benefits of vaccines being delivered directly into the respiratory tract, rather than by traditional injection.

Because inhaled vaccines target the lungs and upper airways where respiratory viruses first enter the body, they are far more effective at inducing a protective immune response, the researchers report.

The reported preclinical study, which was conducted on animal models, has provided the critical proof of concept to enable a Phase 1 clinical trial that is currently under way to evaluate inhaled aerosol vaccines in healthy adults who had already received two doses of a COVID mRNA vaccine.

The tested COVID vaccine strategy was built upon a robust tuberculosis vaccine research program established by Zhou Xing, a co-lead author of the new study and a professor at the McMaster Immunology Research Centre and Department of Medicine.

"What we've discovered from many years' research is that the vaccine delivered into the lung induces all-around protective respiratory mucosal immunity, a property that the injected vaccine is lacking," Xing says.

Currently authorized COVID vaccines are all injected.

"We wanted, first and foremost, to design a vaccine that would work well against any variant," explains the study's co-lead author Matthew Miller, an associate professor at McMaster's Michael G. DeGroote Institute for Infectious Disease Research.

The McMaster COVID vaccine represents one of only a handful developed in Canada. The urgent work is a critical mission of Canada's Global Nexus for Pandemics and Biological Threats, which is based at McMaster.

Researchers compared two types of adenovirus platforms for the vaccine. The viruses serve as vectors that can deliver vaccine directly to the lungs without causing illness themselves.

"We can remain ahead of the virus with our vaccine strategy," says Miller. "Current vaccines are limited because they will need to be updated and will always be chasing the virus."

Both types of the new McMaster vaccine are effective against highly transmissible variants because they are designed to target three parts of the virus, including two that are highly conserved among coronaviruses and do not mutate as quickly as spike. All COVID vaccines currently approved in Canada target only the spike protein, which has shown a remarkable ability to mutate.

"This vaccine might also provide pre-emptive protection against a future pandemic, and that's really important because as we've seen during this pandemic -- and as we saw in 2009 with the swine flu -- even when we are able to rapidly make a vaccine for a pandemic virus, it's already way too late. Millions of people died, even though we were able to make a vaccine in record time," says Miller.

"We have revealed in our report that besides neutralizing antibodies and T cell immunity, the vaccine delivered into the lungs stimulates a unique form of immunity known as trained innate immunity, which is able to provide very broad protection against many lung pathogens besides SARS-CoV-2," Xing adds.

In additional to being needle and pain-free, an inhaled vaccine is so efficient at targeting the lungs and upper airways that it can achieve maximum protection with a small fraction of the dose of current vaccines -- possibly as little as 1 per cent -- meaning a single batch of vaccine could go 100 times further, the researchers say.

"This pandemic has shown us that vaccine supply can be a huge challenge. Demonstrating that this alternative delivery method can significantly extend vaccine supply could be a game changer, particularly in a pandemic setting," says Brian Lichty, an associate professor in the Department of Medicine who co-led the preclinical study along with Miller, Xing and the senior trainees Sam Afkhami and Michael D'Agostino, who are the joint first authors of the study.

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Saturn’s high-altitude winds generate an extraordinary aurorae, study finds

Leicester space scientists have discovered a never-before-seen mechanism fuelling huge planetary aurorae at Saturn.

Saturn is unique among planets observed to date in that some of its aurorae are generated by swirling winds within its own atmosphere, and not just from the planet's surrounding magnetosphere.

At all other observed planets, including Earth, aurorae are only formed by powerful currents that flow into the planet's atmosphere from the surrounding magnetosphere. These are driven by either interaction with charged particles from the Sun (as at the Earth) or volcanic material erupted from a moon orbiting the planet (as at Jupiter and Saturn).

This discovery changes scientists' understanding of planetary aurorae and answers one of the first mysteries raised by NASA's Cassini probe, which reached Saturn in 2004: why can't we easily measure the length of a day on the Ringed Planet?

When it first arrived at Saturn, Cassini tried to measure the bulk rotation rate of the planet, that determines the length of its day, by tracking radio emission 'pulses' from Saturn's atmosphere. To the great surprise of those making the measurements, they found that the rate appeared to have changed over the two decades since the last spacecraft to have flown past the planet -- Voyager 2, also operated by NASA -- in 1981.

Leicester PhD researcher Nahid Chowdhury is a member of the Planetary Science Group within the School of Physics and Astronomy and corresponding author for the study, published in Geophysical Research Letters. He said:

"Saturn's internal rotation rate has to be constant, but for decades researchers have shown that numerous periodic properties related to the planet -- the very measurements we've used at other planets to understand the internal rotation rate, such as the radio emission -- tend to change with time. What's more, there are also independent periodic features seen in the northern and southern hemispheres which themselves vary over the course of a season on the planet.

"Our understanding of the physics of planetary interiors tells us the true rotation rate of the planet can't change this quickly, so something unique and strange must be happening at Saturn. Several theories have been touted since the advent of the NASA Cassini mission trying to explain the mechanism/s behind these observed periodicities. This study represents the first detection of the fundamental driver, situated in the upper atmosphere of the planet, which goes on to generate both the observed planetary periodicities and aurorae.

"It's absolutely thrilling to be able to provide an answer to one of the longest standing questions in our field. This is likely to initiate some rethinking about how local atmospheric weather effects on a planet impact the creation of aurorae, not just in our own Solar System but farther afield too."

Astronomers and planetary scientists based at the University of Leicester led a study alongside colleagues from NASA's Jet Propulsion Laboratory (JPL), the Japan Aerospace Exploration Agency (JAXA), and the Universities of Wisconsin-Madison, Boston, and Lancaster, plus Imperial and University Colleges, London, to resolve the decades-old question.

They measured infrared emissions from the gas giant's upper atmosphere using the Keck Observatory in Hawai'i and mapped the varying flows of Saturn's ionosphere, far below the magnetosphere, over the course of a month in 2017.

This map, when fixed against the known pulse of Saturn's radio aurorae, showed that a significant proportion of the planet's aurorae are generated by the swirling pattern of weather in its atmosphere and are responsible for the planet's observed variable rate of rotation.

Researchers believe the system is driven by energy from Saturn's thermosphere, with winds in the ionosphere observed between 0.3 and 3.0 kilometres per second.

Dr Tom Stallard, Associate Professor in Planetary Astronomy at the University of Leicester, added:

"The University of Leicester has long been involved in measuring the effects of this new discovery -- we've observed how the pulsing aurorae and the wobbling magnetic field lines stretching out into space highlight an apparently changing rotation rate. For two decades our researchers, along with the wider scientific community, have speculated about what might be driving these strange periodicities.

"Over the years, scientific meetings have had late-night discussions about whether the volcanic moon Enceladus might be the cause, or interactions with the thick atmosphere of the moon Titan, or perhaps interactions with Saturn's bright rings. But recently, many researchers have focused on the possibility that it is Saturn's upper atmosphere that causes this variability.

"This search for a new type of aurora harks back to some of the earliest theories about Earth's aurora. We now know that aurorae on Earth are powered by interactions with the stream of charged particles driven from the Sun. But I love that the name Aurora Borealis originates from the 'the Dawn of the Northern Wind'. These observations have revealed that Saturn has a true Aurora Borealis -- the first ever aurora driven by the winds in the atmosphere of a planet."

Dr Kevin Baines, a JPL-Caltech-based co-author of the study and a member of the Cassini Science Team, added:

"Our study, by conclusively determining the origin of the mysterious variability in radio pulses, eliminates much of the confusion into Saturn's bulk rotation rate and the length of the day on Saturn."

Because of the variable rotation rates observed at Saturn, scientists have been prevented from using the regular pulse of radio emission to calculate the bulk internal rotation rate. Fortunately, a novel method was developed by Cassini scientists using gravity-induced perturbations in Saturn's complex ring system, which now seems to be the most accurate means of measuring the planet's bulk rotational period, which was determined in 2019 to be 10 hours, 33 minutes and 38 seconds.

Read more at Science Daily

Bronze Age women altered genetic landscape of Orkney, study finds

An international team led by researchers at the University of Huddersfield has used ancient DNA to rewrite the history of the Orkney islands to show that Orkney actually experienced large-scale immigration during the Early Bronze Age, which replaced much of the local population.

The project was a close collaboration between genetic researchers in Huddersfield and Edinburgh, led by Professor Martin Richards and Dr Ceiridwen Edwards, and archaeologists living and working on Orkney.

Orkney is world-famous for its archaeological heritage. Around 5000 years ago, during the Neolithic period when farming first took hold, it was a hugely influential cultural centre. With many superbly preserved stone dwellings, temples and megalithic monuments, and a style of ceramics that appears to have spread out across Britain and Ireland, it has even been described as "Britain's ancient capital."

Over the thousand years that followed however, as Europe moved into the Bronze Age, it has been widely viewed that somehow Orkney became left behind. Its influence dwindled and the islands became more insular. But with fewer archaeological remains to study, much less was known about this time.

By combining archaeology with the study of ancient DNA from Bronze Age human remains from the Links of Noltland site, on the remote northern island of Westray, researchers now know much more about this time than ever before, and the results have come as a great surprise to geneticists and archaeologists alike.

Firstly, despite the supposed insularity, the team has shown that Orkney experienced large-scale immigration during the Early Bronze Age, which replaced much of the local population. The new arrivals were probably the first to speak Indo-European languages, and carried genetic ancestry derived in part from pastoralists living on the steppe lands north of the Black Sea.

This mirrored what was happening in the rest of Britain and Europe in the third millennium BC. But the researchers found a fascinating difference that makes Orkney highly distinctive.

Across most of Europe, the expansion of pastoralists on the eve of the Bronze Age was typically led by men, with women being sucked into the expanding populations from local farming groups. But in Orkney the researchers found exactly the opposite. The Bronze Age newcomers were mainly women, while male lineages from the original Neolithic population survived for at least another thousand years -- something not seen anywhere else. These Neolithic lineages, however, were replaced from the Iron Age and are vanishingly rare today.

But why was Orkney so different? Dr Graeme Wilson and Hazel Moore of the Orkney-based EASE Archaeology, who excavated the Links of Noltland, argue that the answer may lie in the long-term stability and self-sufficiency of farmsteads on Orkney, which the genetic data suggests may have already been male dominated by the peak of the Neolithic. When a Europe-wide recession hit towards the end of the Neolithic, they may have been uniquely placed to weather harsher times and maintain their grip on the population as newcomers arrived.

This implies that Orkney was much less insular than has long been assumed, and that there was a protracted period of negotiation between the indigenous males and the newcomers from the south, over many generations.

"This shows that the third-millennium BC expansion across Europe was not a monolithic process but was more complex and varied from place to place," explained Dr George Foody, one of the lead researchers on the project from the University of Huddersfield.

The results have been surprising for both the archaeologists and geneticists on the team, although for different reasons: the archaeologists did not expect such large-scale immigration, whereas the geneticists did not foresee survival of the Neolithic male lineages.

The University's Director of the Evolutionary Genomics Research Centre Professor Martin Richards said: "This research shows how much we still have to learn about one of the most momentous events in European prehistory -- how the Neolithic came to an end."

Read more at Science Daily

New 'vertical map' of airborne microorganisms indicates how global warming will impact global ecosystems

In a landmark study of airborne microorganisms from ground level up to 3,500 metres, scientists from the Singapore Centre for Environmental Life Sciences Engineering (SCELSE) at Nanyang Technological University, Singapore (NTU Singapore) have found that bacteria and fungi populate the planet's lower atmosphere in very specific ways and if changed, may negatively impact human health and food supply.

Using a combination of a 200-metre meteorological tower and a research aircraft that circled at different heights from 300 metres to 3,500 metres to gather the necessary measurements, the researchers found that temperature was the single most important factor influencing the composition of airborne microbial communities.

As the temperature of the air changes, the species found and the ratio of bacteria to fungi change significantly. These findings suggest that the currently observed increase in global temperature will have an impact on the atmospheric microbial ecosystem, as well as planetary terrestrial and aquatic ecosystems.

The study was published today in the peer-reviewed journal Proceedings of the National Academy of Sciences (PNAS) by a team of interdisciplinary scientists led by NTU Professor Stephan Schuster, Research Director (Meta-'omics & Microbiomes) at SCELSE.

Atmospheric microorganisms, collectively known as the air microbiome, consist of bacteria and fungi, and largely remain suspended in air once they are blown off the planet's surface.

Only a fraction of these microorganisms find their way back down to the surface, when they are washed down by rain droplets or fall back down together with larger particles such as sand grains or dust.

"Our research generated a comprehensive 'vertical map' of airborne microorganisms in the planet's atmosphere," said Prof Schuster, the study's corresponding author.

"We found that the composition of the air microbiome in our atmosphere is determined by the temperature. As global air temperatures are rising due to climate change, this could lead to very significant changes in the air microbiome with serious consequences for people and the planet."

"If the composition of the air microbiome changes globally, it may affect human health, exacerbating respiratory syndromes in susceptible patients, or it could affect the yield of agricultural crops, which then threatens our food security. Natural processes that have worked for thousands of years such as carbon cycling of this planet may also be changed."

"With our latest research paper, we are a step closer to showing that air has its own microbial ecosystem, much like those on land and in the sea. We expect that changes in the air microbiome will also have knock-on effects on terrestrial and aquatic ecosystems," adds Prof Schuster.

The vertical map of microorganisms also provides a starting point for future ecological surveys and the necessary measures not only for the protection of global environments, but also for agricultural production sites, which may be negatively impacted by changes to the airborne microbial communities.

With the new dataset as a baseline, scientists can also model and predict the changes in the air microbiome if temperatures were to rise by two degrees or more, said the research team.

Key discoveries

To measure the air microbiome high above the ground, the team used a specialised research aircraft from the Technische Universität Braunschweig, Germany, to collect synchronised measurements of meteorological parameters and airborne biomass samples up to a height of 3,500 metres.

The research team on the aircraft coordinated the sampling times with a team stationed at the 200-metre-high meteorological tower at the Karlsruhe Institute of Technology (KIT) in Karlsruhe, Germany.

A total of 480 vertical air samples were collected from Germany, which were brought back to Singapore to be analysed. The team was surprised to find that the composition of microorganisms above 1,000 metre was stable, independent of day or night. These air layers act as a "sink in the sky," where bacteria accumulate in higher numbers than at the ground. The team identified over 10,000 different species of airborne microbes from the samples taken above 1,000 metres.

This was very different from the air samples that were taken below 300 metres, which were shown to follow the 24-hour day and night cycle (called the diel cycle), where the air composition changes from bacteria and some fungi dominating during the day, to wood-rotting fungi dominating in the night.

The discovery of the diel cycle of airborne microorganisms was first published in PNAS in 2019[1][1], when the same research team studied the tropical air in Singapore using air samples taken at various levels of a 50-storey high-rise residential building named Pinnacle@Duxton.

In its latest study, the team also reported that atmospheric turbulence -- wind and weather -- is the primary driver of microbial aerosol dynamics, which determines how microorganisms in the air are distributed.

Driven by the day/night temperature changes, air masses become layered (stratified) at night and mixed during the day, resulting in the stratification of the air microbiome across different heights of the lower part of atmosphere.

"For the first time, meteorological and biological data of the atmosphere were measured in unison, allowing us to develop a comprehensive hypothesis about the effects of atmospheric turbulence on the dispersal of microorganisms in the lower atmosphere," said Prof Schuster.

Researchers further noticed that higher air layers contained an up-to-20-times higher concentration of radio-tolerant bacteria, which are known to withstand ionising radiation, desiccation, UV radiation, or oxidising agents. Of these bacteria, one species known as Deinococcus radiodurans is known to withstand a 1,000-fold higher radiation dose than the human body.

The team hypothesised that the ionising rays from sun and space had contributed to the development of radioactive tolerance in these bacteria at greater height, whereas bacteria on the ground have not been exposed to such levels of radiation.

Sampling for airborne life on Mars?

Based on their experiments, the researchers comment that their air sampling technologies could in principle, be used for investigating the atmosphere of neighbouring planets, such as Mars.

By tapping on the knowledge that microorganisms will aggregate in a planet's atmosphere, it could provide an alternative to the current method of sampling, which is done by a robotic vehicle drilling and collecting soil samples.

For instance, a robot with an air sampler could collect microorganisms from the atmosphere by trapping them in an air filter, and sending the filter back to earth, in a potential future Mars sample-return mission.

The air microbiome study is one of SCLESE's flagship research projects together with its research into terrestrial and aquatic ecosystems. The project was carried out over eight years, and has resulted in more than 40 papers, culminating with these results. The air microbiome research was supported by a Singapore Ministry of Education Tier 3 grant, SCELSE, and NTU.

Sustainability, climate change and the environment are key research pillars for NTU Singapore and are part of its Sustainability Manifesto launched last year. The University will continue fundamental and applied research to develop sustainable solutions that can mitigate the effects of natural disasters and climate change, and to meet the demand for food with alternative food sources.

Over the last two years during the pandemic, Prof Schuster and his team have pivoted to use their air sampling technology to detect and analyse the SARS-COV-2 virus from indoor air, a technique that demonstrated greater sensitivity than surface swab tests.

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COVID-19 infections increase risk of heart conditions up to a year later, study finds

An in-depth analysis of federal health data indicates that people who have had COVID-19 are at increased risk of developing cardiovascular complications within the first month to a year after infection. Such complications include disruptive heart rhythms, inflammation of the heart, blood clots, stroke, coronary artery disease, heart attack, heart failure or even death.

Such problems occur even among previously healthy individuals and those who have had mild COVID-19 infections, according to the study, from researchers at Washington University School of Medicine in St. Louis and the Veterans Affairs St. Louis Health Care System.

The research is published Feb. 7 in Nature Medicine.

"We wanted to build upon our past research on COVID's long-term effects by taking a closer look at what's happening in people's hearts," said senior author Ziyad Al-Aly, MD, an assistant professor of medicine at Washington University. "What we're seeing isn't good. COVID-19 can lead to serious cardiovascular complications and death. The heart does not regenerate or easily mend after heart damage. These are diseases that will affect people for a lifetime."

More than 380 million people globally have been infected with the virus since the pandemic started.

"Consequently, COVID-19 infections have, thus far, contributed to 15 million new cases of heart disease worldwide," said Al-Aly, who treats patients within the VA St. Louis Health Care System. "This is quite significant. For anyone who has had an infection, it is essential that heart health be an integral part of post-acute COVID care."

Cardiovascular disease -- an umbrella term that refers to various heart conditions, thrombosis and stroke -- is the leading cause of death in the United States and the world. The Centers for Disease Control and Prevention (CDC) estimates that one out of every four Americans dies of heart disease each year.

Additionally, heart disease comes with a hefty price tag, according to the CDC, costing the U.S. about $363 billion each year in health-care services, medications and productivity lost to death.

"For people who were clearly at risk for a heart condition before becoming infected with SARS-CoV-2, the findings suggest that COVID-19 may amplify the risk," said Al-Aly, who is also director of the Clinical Epidemiology Center and chief of the Research and Education Service at the Veterans Affairs St. Louis Health Care System.

"But most remarkably, people who have never had any heart problems and were considered low risk are also developing heart problems after COVID-19," he added. "Our data showed an increased risk of heart damage for young people and old people; males and females; Blacks, whites and all races; people with obesity and people without; people with diabetes and those without; people with prior heart disease and no prior heart disease; people with mild COVID infections and those with more severe COVID who needed to be hospitalized for it."

The researchers analyzed de-identified medical records in a database maintained by the U.S. Department of Veterans Affairs, the nation's largest integrated health-care delivery system. The researchers created a controlled dataset that included health information of 153,760 people who had tested positive for COVID-19 sometime from March 1, 2020, through Jan. 15, 2021, and who had survived the first 30 days of the disease. Very few of the people in the study were vaccinated prior to developing COVID-19, as vaccines were not yet widely available at the time of enrollment.

Statistical modeling was used to compare cardiovascular outcomes in the COVID-19 dataset with two other groups of people not infected with the virus: a control group of more than 5.6 million patients who did not have COVID-19 during the same time frame; and a control group of more than 5.8 million people who were patients from March 2018 through January 2019, well before the virus spread and the pandemic settled in.

The study does not include data involving the virus's delta and omicron variants, which began spreading rapidly in the latter half of 2021.

The COVID-19 patients in the study were mostly older, white men; however, the researchers also analyzed data that included women and adults of all ages and races.

The researchers analyzed heart health over a year-long period. Heart disease, including heart failure and death, occurred in 4% more people than those who had not been infected with COVID-19.

"Some people may think 4% is a small number, but it's not, given the magnitude of the pandemic," Al-Aly said. "That translates to roughly 3 million people in the U.S. who have suffered cardiovascular complications due to COVID-19."

Compared with those in the control groups without any infections, people who contracted COVID-19 were 72% more likely to suffer from coronary artery disease, 63% more likely to have a heart attack and 52% more likely to experience a stroke.

Overall, those infected with the virus were 55% more likely than those without COVID-19 to suffer a major adverse cardiovascular event, which includes heart attack, stroke and death.

"Our findings highlight the serious long-term cardiovascular consequences of having a COVID-19 infection and emphasize the importance of getting vaccinated against COVID-19 as a way to prevent heart damage; this also underscores the importance of increasing accessibility to the vaccines in countries with limited resources," Al-Aly said.

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Poor sleep can triple risk for heart disease

Individual aspects of poor sleep can be detrimental to heart health. But if you combine them, the risk of heart disease can increase by as much as 141 percent. That's the finding of a new study published in the journal Scientific Reports.

The University of South Florida-led study reviewed sleep data of 6,820 U.S. adults with an average age of 53 who self-reported their sleep characteristics and heart disease history. Among the participants, 633 also wore a research device (actigraphy) around their wrist that captured sleep activity.

Researchers focused on multiple aspects of sleep health, such as regularity, satisfaction, alertness during waking hours, timing of sleep, sleep efficiency and sleep duration and linked them to physician-diagnosed heart disease. They found that each additional increase in self-reported sleep health problems was associated with a 54 percent increased risk of heart disease. The estimated risk of heart disease associated with an increase in sleep health problems was much higher for those who provided sleep data by both self-report and the research device. They had a 141 percent increase -- a figure that could be perceived to be more accurate.

"These findings show the importance of assessing 'co-existing sleep health problems' within an individual to capture the risk of heart disease. This is one of the first studies showing that, among well-functioning adults in midlife, having more sleep health problems may increase the risk of heart disease," said lead author Soomi Lee, assistant professor of aging studies and director of the STEALTH lab at USF. "The higher estimated risk in those who provided both self-report and actigraphy sleep data suggests that measuring sleep health accurately and comprehensively is important to increase the prediction of heart disease."

The research team asked participants about their health, including if their physician confirmed a heart condition such as arrythmia, heart murmur or an enlarged heart. High blood pressure was not considered a diagnosis as it's labeled a risk factor for heart disease rather than a heart disease condition. They also controlled for family history of heart disease and sociodemographic factors, such as race, sex, smoking, depression and physical activity.

Researchers found that while women reported having more sleep health problems, men were more likely to suffer heart disease -- yet gender did not impact the overall correlation between the two factors. They also found that Black participants had more sleep health problems and a higher prevalence of heart disease than white participants, but the strong association between sleep health and heart disease did not differ by race in general.

Lee says while sleep health is important for all ages, the team focused on middle adulthood as it spans for a longer period of time and consists of diverse and more stressful life experiences due to work and family roles. This is also when precursors for heart disease and age-related sleep issues begin to arise.

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Supermountains controlled the evolution of life on Earth

Giant mountain ranges at least as high as the Himalayas and stretching up to 8,000 kilometres across entire supercontinents played a crucial role in the evolution of early life on Earth, according to a new study by researchers at The Australian National University (ANU).

The researchers tracked the formation of these supermountains throughout Earth's history using traces of zircon with low lutetium content -- a combination of mineral and rare earth element only found in the roots of high mountains where they form under intense pressure.

The study found the most giant of these supermountains only formed twice in Earth's history -- the first between 2,000 and 1,800 million years ago and the second between 650 and 500 million years ago. Both mountain ranges rose during periods of supercontinent formation.

Lead author, ANU PhD candidate Ziyi Zhu, said there are links between these two instances of supermountains and the two most important periods of evolution in Earth's history.

"There's nothing like these two supermountains today. It's not just their height -- if you can imagine the 2,400 km long Himalayas repeated three or four times you get an idea of the scale," she said.

"We call the first example the Nuna Supermountain. It coincides with the likely appearance of eukaryotes, organisms that later gave rise to plants and animals.

"The second, known as the Transgondwanan Supermountain, coincides with the appearance of the first large animals 575 million years ago and the Cambrian explosion 45 million years later, when most animal groups appeared in the fossil record."

Co-author Professor Jochen Brocks said: "What's stunning is the entire record of mountain building through time is so clear. It shows these two huge spikes: one is linked to the emergence of animals and the other to the emergence of complex big cells."

When the mountains eroded they provided essential nutrients like phosphorus and iron to the oceans, supercharging biological cycles and driving evolution to greater complexity.

The supermountains may also have boosted oxygen levels in the atmosphere, needed for complex life to breathe.

"The early Earth's atmosphere contained almost no oxygen. Atmospheric oxygen levels are thought to have increased in a series of steps, two of which coincide with the supermountains," Ms Zhu said.

"The increase in atmospheric oxygen associated with the erosion of the Transgondwanan Supermountain is the largest in Earth's history and was an essential prerequisite for the appearance of animals."

There is no evidence of other supermountains forming at any stage between these two events, making them even more significant.

"The time interval between 1,800 and 800 million years ago is known as the Boring Billion, because there was little or no advance in evolution," co-author Professor Ian Campbell said.

"The slowing of evolution is attributed to the absence of supermountains during that period, reducing the supply of nutrients to the oceans.

Read more at Science Daily