Quantum discovery offers glimpse into other-worldly realm

The field of quantum physics is rife with paths leading to tantalising new areas of study, but one rabbit hole offers a unique vantage point into a world where particles behave differently -- through the proverbial looking glass.

Dubbed the 'Alice ring' after Lewis Carroll's world-renowned stories on Alice's Adventures in Wonderland, the appearance of this object verifies a decades-old theory on how monopoles decay. Specifically, that they decay into a ring-like vortex, where any other monopoles passing through its centre are flipped into their opposite magnetic charges.

Published in Nature Communications on August 29, these findings mark the latest discovery in a string of work that has spanned the collaborative careers of Aalto University Professor Mikko Möttönen and Amherst College Professor David Hall.

'This was the first time our collaboration was able to create Alice rings in nature, which was a monumental achievement,' Möttönen said.

'This fundamental research opens new doors into understanding how these structures and their analogues in particle physics function in the universe,' Hall added.

The long-standing relationship, titled the Monopole Collaboration, initially proved the existence of a quantum analogue of the magnetic monopole in 2014, isolated quantum monopoles in 2015, and eventually observed one decay into the other in 2017.

Monopoles remain an elusive concept in the arena of quantum physics. As the name suggests, monopoles are the solitary counterpart of dipoles, which carry a positive charge at their north pole and a negative charge at the south. In contrast, a monopole carries only either a positive or negative charge.

While the concept sounds simple, realising a true monopole has proven to be a career-defining task. Here's how the Monopole Collaboration has done it: they manipulated a gas of rubidium atoms prepared in a nonmagnetic state near absolute zero temperature. Under these extreme conditions, they were then able to create a monopole by steering a zero point of a three-dimensional magnetic field into the quantum gas.

Laying theoretical groundwork

These quantum monopoles are ephemeral by nature, decaying a few milliseconds after their creation. It is within this instability that the Alice ring takes shape.

'Think of the monopole as an egg teetering at the top of a hill,' Möttönen said. 'The slightest perturbations can send it crashing down. In the same way, monopoles are subject to noise that triggers their decay into Alice rings.'

While monopoles are short-lived, the research group simulated stable Alice rings for as long as 84 milliseconds -- over 20 times longer than the monopole lifespan. This leads researchers to be optimistic that future experiments will reveal even more peculiar properties of Alice rings.

'From a distance, the Alice ring just looks like a monopole, but the world takes a different shape when peering through the centre of the ring,' Hall said.

'It is from this perspective that everything seems to be mirrored, as if the ring were a gateway into a world of antimatter instead of matter,' Möttönen added.

In theory, a monopole passing through the centre of an Alice ring would be transformed into an anti-monopole of opposite charge. Correspondingly, the Alice ring's charge would change as well. While this phenomenon has not yet been experimentally observed, Möttönen said the topological structure of Alice rings necessitates this behaviour.

The experimental work was conducted at Amherst College primarily by PhD candidate Alina Blinova and Hall, while Möttönen and his team were responsible for running matching simulations. This way, the two teams were able to confirm the interpretation of the experimental observations.

'It is simply amazing to have such a major discovery as the finale of my PhD work,' Blinova said.

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Groundwater depletion rates in India could triple in coming decades as climate warms, study shows

A new University of Michigan-led study finds that farmers in India have adapted to warming temperatures by intensifying the withdrawal of groundwater used for irrigation. If the trend continues, the rate of groundwater loss could triple by 2080, further threatening India's food and water security.

Reduced water availability in India due to groundwater depletion and climate change could threaten the livelihoods of more than one-third of the country's 1.4 billion residents and has global implications. India recently overtook China to become the world's most populous nation and is the second-largest global producer of common cereal grains including rice and wheat.

"We find that farmers are already increasing irrigation use in response to warming temperatures, an adaptation strategy that has not been accounted for in previous projections of groundwater depletion in India," said study senior author Meha Jain, assistant professor at U-M's School for Environment and Sustainability. "This is of concern, given that India is the world's largest consumer of groundwater and is a critical resource for the regional and global food supply."

The lead author is Nishan Bhattarai of the Department of Geography and Environmental Sustainability at the University of Oklahoma, formerly a postdoctoral researcher in Jain's U-M lab.

The study, scheduled for online publication Sept. 1 in the journal Science Advances, analyzed historical data on groundwater levels, climate and crop water stress to look for recent changes in withdrawal rates due to warming. The researchers also used temperature and precipitation projections from 10 climate models to estimate future rates of groundwater loss across India.

Previous studies have focused on the individual effects of climate change and groundwater depletion on crop production in India. Those studies did not account for farmer decision-making, including how farmers may adapt to changing climate through changes in irrigation decisions.

The new study takes into account the fact that warmer temperatures may increase water demand from stressed crops, which in turn may lead to increased irrigation by farmers.

"Using our model estimates, we project that under a business-as-usual scenario, warming temperatures may triple groundwater depletion rates in the future and expand groundwater depletion hotspots to include south and central India," Bhattarai said.

"Without policies and interventions to conserve groundwater, we find that warming temperatures will likely amplify India's already existing groundwater depletion problem, further challenging India's food and water security in the face of climate change."

Previous studies found that climate change could decrease the yield of staple Indian crops by up to 20% by mid-century. At the same time, the country's groundwater is being depleted at an alarming rate, primarily because of water withdrawal for irrigation.

For the newly published study, the researchers developed a dataset that contains groundwater depths from thousands of wells across India, high-resolution satellite observations that measured crop water stress, and temperature and precipitation records.

Most climate models call for increased temperature, increased monsoon (June through September) precipitation and decreased winter precipitation in India over the coming decades. The U-M-led research team found that warming temperatures coupled with declining winter precipitation more than offset added groundwater recharge from increased monsoon precipitation, resulting in accelerated groundwater declines.

Across various climate-change scenarios, their estimates of groundwater-level declines between 2041 and 2080 were more than three times current depletion rates, on average.

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Bat study reveals how the brain is wired for collective behavior

The same neurons that help bats navigate through space may also help them navigate collective social environments, finds a new study published today in the journal Nature.

Many mammals -- including bats and humans -- are believed to navigate with the help of a brain structure called the hippocampus, which encodes a mental "map" of familiar surroundings. For example, as you walk around your neighborhood or commute to work, individual "place" neurons in the hippocampus fire to indicate where you are.

In the new study, researchers at the University of California, Berkeley, used wireless neural recording and imaging devices to "listen in" on the hippocampal brain activity of groups of Egyptian fruit bats as they flew freely within a large flight room -- often moving among tightly clustered social groups -- while tracking technology recorded the bats' movements.

The researchers were surprised to find that, in this social setting, the bat's place neurons encoded far more information than simply the animal's location. As a bat flew toward a landing spot, the firing of place neurons also contained information about the presence or absence of another bat at that spot. And when another bat was present, the activity of these neurons indicated the identity of the bat they were flying toward.

"This is one of the first papers to show identity representation in a non-primate brain," said study senior author Michael Yartsev, an associate professor of bioengineering and neuroscience at UC Berkeley. "And surprisingly, we found it in the hub of what was supposed to be the brain's GPS.We found that it still acts as a GPS, but one that is also tuned to the social dynamic in the environment."

While not as visually stunning as a school of fish or a murmuration of birds, highly social animals like humans and bats also exhibit forms of collective behavior, said study first author Angelo Forli, a postdoctoral fellow in Yartsev's NeuroBat lab.

"Social animals, like humans, will coordinate in space to achieve different goals," Forli said. "It might be just visiting others. It might be moving together, as in the case of classical collective behaviors or playing a soccer match. Or it might be other forms of cooperation or conflict."

Due to the complexity of the experiment, Forli initially had doubts about whether allowing groups of bats to fly and interact freely would yield results about the neural basis of collective behavior. He was concerned that the movements of the bats and their social interactions might be too random to uncover robust relationships between their neural activity and their behavior.

So he was pleasantly surprised when the bats spontaneously established a handful of specific resting spots within the flight room and followed very similar trajectories when traveling among them. The bats also showed strong preferences for flying toward specific "friend" bats, often landing very close to or even on top of each other.

"We found that if you put together a small group of bats in a room, they would not actually behave randomly, but would show precise patterns of behavior," Forli said. "They would spend time with specific individuals and show specific and stable places where they liked to go."

These precise patterns of behavior allowed Forli to identify not only the neural activity associated with different flight trajectories, but also how the neural activity changed depending on the identity of the bat present at the target location and the movements of other bats.

"By recording just a handful of those neurons from this brain structure, we can really know what the bats were doing in their social space," Yartsev said. "We could find out if they were going to an empty location or to a location where there were other individuals, which is really surprising."

In recent years, Yartsev and his NeuroBat Lab have used a variety of wireless neural recording devices and flight tracking technologies to uncover a number of surprising details about the brain, including how bats' neural activity syncs up while they socialize; how activity in the frontal cortex helps bats identify self vs. others during vocal interactions; how bats' hippocampus maps not only specific locations, but full flight trajectories; and even how stable spatial memories might be stored in the brain.

This new study brings together the team's work on navigation and social behavior, showing how these two things are fundamentally intertwined within the brain. The findings also help illuminate why damage to the hippocampus in humans has been linked to both social and spatial aspects of memory loss in neurodegenerative diseases like Alzheimer's.

"Our episodic memories are a combination of the environment where we are located and our experiences within it -- including, of course, our social experiences," Yartsev said. "Our results are surprising, in the sense that no one has observed this connection before in groups of animals and at the individual neuron level. But they also make sense in that they are very consistent with deficits that people with damage to the hippocampus experience."

Finally, this study highlights a very important point, Yartsev said. While most of the neuroscientific community examines the brain under "simplified" or "artificial" conditions that are often far removed from the natural behavior the brain has evolved to promote, this work demonstrates the power of the natural approach to neuroscience research.

"For half a century, people have been studying place neurons, but 99% of that work has been done in single animals moving in an empty box," Yartsev said. "Our findings suggest that there is a lot that can be learned when neuroscience research focuses on natural behavior."

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Webb reveals new structures within iconic supernova

NASA's James Webb Space Telescope has begun the study of one of the most renowned supernovae, SN 1987A (Supernova 1987A). Located 168,000 light-years away in the Large Magellanic Cloud, SN 1987A has been a target of intense observations at wavelengths ranging from gamma rays to radio for nearly 40 years, since its discovery in February of 1987. New observations by Webb's NIRCam (Near-Infrared Camera) provide a crucial clue to our understanding of how a supernova develops over time to shape its remnant.

This image reveals a central structure like a keyhole. This center is packed with clumpy gas and dust ejected by the supernova explosion. The dust is so dense that even near-infrared light that Webb detects can't penetrate it, shaping the dark "hole" in the keyhole.

A bright, equatorial ring surrounds the inner keyhole, forming a band around the waist that connects two faint arms of hourglass-shaped outer rings. The equatorial ring, formed from material ejected tens of thousands of years before the supernova explosion, contains bright hot spots, which appeared as the supernova's shock wave hit the ring. Now spots are found even exterior to the ring, with diffuse emission surrounding it. These are the locations of supernova shocks hitting more exterior material.

While these structures have been observed to varying degrees by NASA's Hubble and Spitzer Space Telescopes and Chandra X-ray Observatory, the unparalleled sensitivity and spatial resolution of Webb revealed a new feature in this supernova remnant -- small crescent-like structures. These crescents are thought to be a part of the outer layers of gas shot out from the supernova explosion. Their brightness may be an indication of limb brightening, an optical phenomenon that results from viewing the expanding material in three dimensions. In other words, our viewing angle makes it appear that there is more material in these two crescents than there actually may be.

The high resolution of these images is also noteworthy. Before Webb, the now-retired Spitzer telescope observed this supernova in infrared throughout its entire lifespan, yielding key data about how its emissions evolved over time. However, it was never able to observe the supernova with such clarity and detail.

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Evolutionary imbalance explains global plant invasions

Plant species from certain geographic regions are more successful in spreading outside their native ranges than others -- but why? An international research team led by Konstanz ecologists provides answers by exploring how the ecological and evolutionary histories of plants can influence their relationships with humans and their success as invaders.

Human activities -- for example, global trade and travel -- are driving the spread of plants beyond their natural ranges and around the globe. However, not all species benefit equally from these movements; only some are able to successfully establish populations (i.e. naturalize) in new locations. Data on the global distribution of alien plants reveals that plants originating from certain geographic regions are more successful at naturalizing than others.

The evolutionary imbalance hypothesis (EIH) offers possible explanations for this phenomenon, but has not yet been verified on a global scale. An international research team led by biologist Mark van Kleunen from the University of Konstanz has now succeeded in confirming key predictions of this hypothesis using extensive global data. In their study in Nature Ecology & Evolution, the researchers also discover intriguing similarities in the origins of plants that successfully establish populations outside their natural ranges and those that humans have selected for cultivation and economic use -- suggesting that biogeographic factors influence biological and cultural systems in similar ways.

Dating back to Darwin

At its essence, the ideas of the EIH date back to Charles Darwin. "Darwin proposed that geographic barriers divide the Earth's ecosystems into various evolutionary arenas," says Trevor Fristoe, first author of the study and ecologist at the Department of Biology at the University of Konstanz. Within each of these arenas, the organisms inhabiting them would be exposed to unique geographic and ecological conditions that influence the intensity of natural selection. "The result is differences in the absolute fitness for species originating from different regions -- evolutionary imbalances -, and these differences have consequences for which species are more likely to successfully establish in new areas when barriers are removed," Fristoe continues.

Based on these ideas, the EIH makes predictions about the characteristics of global regions that drive the evolution of particularly successful aliens. For example, larger regions should support larger populations and higher genetic diversity to allow for more efficient natural selection. Species-rich regions should serve as intense proving grounds where species must evolve to persist in the presence of a wide variety of competitors and enemies.

The current study tested these predictions on a global scale. For this, the researchers used an unprecedented data set that included the native and alien distributions of over 99 percent of all known seed plants -- over 330,000 species. Consistent with the EIH, they demonstrated that plants originating from vast, species-rich regions are among the most successful alien plants. "Thus, our study confirms two key predictions of the EIH on a global scale," emphasizes Mark van Kleunen, head of the international research team.

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Tiny mineral inclusions picture the chemical exchange between Earth's mantle and atmosphere

Using synchrotron techniques, scientists have unveiled important information on The Great Oxidation Event by studying apatite inclusions in zircon crystals from old magmas with the ESRF -- Extremely Brilliant Source. The results are published in Nature Geoscience.

Around 2.4 billion years ago, a pivotal moment in Earth's history took place: The Great Oxidation Event. During this period, a significant amount of oxygen accumulated in the atmosphere. This surge in oxygen production led to a dramatic shift in the composition of the atmosphere, altering the chemistry of the planet. The event marked a turning point as oxygen levels rose, enabling the development of more complex multicellular life forms and fundamentally reshaping Earth's ecosystems.

Plate tectonics are an effective mechanism for the cycling and interchange of elements among Earth's surface, atmosphere, and mantle. As mountains undergo weathering and erosion through interactions with water and the atmosphere, they break down into sediments. These sediments are then partially returned to the mantle through subduction processes (one tectonic plate sinking beneath another). The formation of magmas in the mantle above subduction zones provides a unique opportunity to explore how the atmosphere could have impacted the mantle by assimilating materials from subducted sediments, offering insights into this intriguing geological relationship.

Scientists have long tried to study the interaction between atmosphere and the Earth's mantle. The mission is already complicated to be accomplished in the modern Earth, and even more so in the early Earth, when the atmosphere and plate tectonics were changing at rapid rates. A team led by the University of Montpellier and University of Portsmouth teamed up with the ESRF -- The European Synchrotron- and found a way to overcome obstacles by studying apatite inclusions in zircon from subduction zones.

"In 2017, a paper on the mineral apatite unveiled that when it grows at reduced conditions, meaning there is little or no free oxygen for chemical reactions, its sulphur would show a very specific signature. However, if it crystalised in oxidised conditions, the sulphur inside the apatite would look very different. This means that apatite is a proxy for redox conditions," explains Hugo Moreira, a CNRS postdoctoral researcher at the University of Montpellier and first author of the paper.

Moreira and colleagues decided to explore inclusions of phosphate-mineral apatite in zircon grains that are crystallized in magmas formed in an ancient subduction zone, and measured their sulphur valence speciation using X-ray absorption near edge structure (XANES) at the ESRF, the brightest synchrotron light source.

Sulphur incorporation and speciation in apatite is intrinsically dependent on the oxygen fugacity of the magma and therefore ideal for assessing the oxidation state during the evolution of magmatic systems. "Using apatite inclusions in zircons rather than apatite from the rock matrix was paramount, as the inclusions have been shielded by the extremely robust zircon crystals, preserving their original composition," explains Moreira.

The experiment results show that apatite inclusions in zircons from magmas that crystallised prior to the Great Oxidation Event have a relatively reduced sulphur redox state, whereas after the Great Oxidation Event they are more oxidised. The analysis on zircon shows that these magmas shared a similar source and that the younger samples had incorporated a sediment component. Overall, the clear implication is that sediments affected by an increasingly oxidised atmosphere modified the mantle and shifted the fugacity of magmas towards more oxidised conditions.

"Our study shows that investigating apatite inclusions in zircon using synchrotron X-rays is a powerful tool to constraint a critical magma parameter," concludes Moreira.

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Using evidence from last Ice Age, scientists predict effects of rising seas on coastal habitats

The rapid sea level rise and resulting retreat of coastal habitat seen at the end of the last Ice Age could repeat itself if global average temperatures rise beyond certain levels, according to an analysis by an international team of scientists from more than a dozen institutions, including Rutgers.

In a study published in Nature, scientists reported how ancient coastal habitats adapted as the last glacial period ended more than 10,000 years ago and projected how they are likely to change with this century's predicted sea level rise. They conducted their analysis by examining the ocean sediments of ancient shorelines from a time when oceans rose rapidly, mainly because of melting ice sheets in the Northern Hemisphere. This examination allowed them to infer how ancient coastal habitats changed and formed the basis of improved predictions about the present.

"Every ton of carbon dioxide humankind emits turns up the global thermostat, which in turn increases the pace of global sea level rise," said Robert Kopp, a Distinguished Professor in the Department of Earth and Planetary Sciences in the Rutgers School of Arts and Sciences and an author of the study. "The faster the oceans rise, the greater the threat to tidal marshes, mangroves and coral reefs around the world. For example, in our analysis, most tidal marshes are likely to be able to keep up with sea level rise under 1.5 degrees Celsius [2.7 degrees Fahrenheit] of warming, but two-thirds are unlikely to be able to keep up with 2 degrees Celsius [3.6 degrees Fahrenheit] of warming."

The temperature ranges mentioned in the study are significant because they relate directly to the Paris Agreement, an international treaty on climate change adopted in 2015, said Kopp, who is also the director of the Megalopolitan Coastal Transformation Hub and co-director of the University Office of Climate Action. The goal of the Paris treaty is to substantially reduce carbon emissions worldwide to limit the global temperature increase in this century to 2 degrees Celsius above preindustrial levels while pursuing efforts to limit the increase even further to 1.5 degrees Celsius.

The study predicted higher global temperatures will provoke sea level rises that will lead to instability and profound changes to coastal ecosystems, including tidal marshes, mangrove forests, coral reefs and coral islands.

Tidal marshes -- low-lying areas flooded and drained by tidal salt water -- protect many of the world's coastlines. They sequester pollutants, absorb carbon dioxide and protect nearby communities from storm surge and flooding. They are common along the Atlantic shores of North America. Large expanses of tidal marshes line New Jersey's coast.

"This new paper provides evidence from geological history that, without mitigation and under current projections, tidal marshes will not have the capacity to adjust," said Judith Weis, a Professor Emerita of Biological Sciences at Rutgers-Newark who isn't an author of the study but is an expert on tidal marshes. "For many tidal marshes in New Jersey, this is not a prediction but a description of the present situation, in which sea level is rising faster than the marshes can increase their elevation. This makes it even more vital to reduce climate change as rapidly as possible."

Tidal marshes and mangrove forests adapt to rising seas by accumulating sediment and moving slowly inland.

"Mangroves and tidal marshes act as a buffer between the ocean and the land -- they absorb the impact of wave action, prevent erosion and are crucial for biodiversity of fisheries and coastal plants," said Neil Saintilan, the paper's lead author and a professor at Macquarie University in Sydney, Australia. "When the plants become water-logged due to higher sea levels, they start to flounder."

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Scientists detect and validate the longest-period exoplanet found with TESS

Scientists from The University of New Mexico (UNM), and Massachusetts Institute of Technology (MIT) have detected and validated two of the longest-period exoplanets found by TESS to date. These long period large exoplanets orbit a K dwarf star and belong to a class of planets known as warm Jupiters, which have orbital periods of 10-200 days and are at least six times Earth's radius. This recent discovery offers exciting research opportunities for the future of finding long-period planets that resemble those in our own solar system.

The research titled, TOI-4600 b and c: Two long-period giant planets orbiting an early K dwarf will be published in a future issue of The Astrophysical Journal Letters. The exoplanets, TOI-4600 b and c, were detected using photometric data from the Transiting Exoplanet Survey Satellite (TESS) and followed up with observations using the telescopes on the ground since they provide better resolution.

The observing strategy adopted by NASA's TESS, which divides each hemisphere into 13 sectors that are surveyed for roughly 28 days, is producing the most comprehensive all-sky search for transiting planets. This approach has already proven its capability to detect both large and small planets around different kinds of stars. In the case of TOI-4600, the star is a K dwarf star, also known as an orange dwarf, which are stars slightly smaller and cooler than the Sun.

Exoplanets must transit their host stars at least twice within TESS 's observing span to be detected with the correct period by the Science Processing Operations Center (SPOC) pipeline and the Quick Look Pipeline (QLP), which search the 2-minute and 30-minute cadence TESS data, respectively. Because 74 percent of TESS' total sky coverage is only observed for 28 days, the majority of TESS exoplanets detected have periods less than 40 days. Therefore, TOI-4600 b's 82.69-day, or nearly 3-month, and TOI-4600 c's 482.82-day, or 16-month, periods make their discoveries even more valuable.

The University of New Mexico's Ismael Mireles, the lead author of the paper, along with collaborators including Diana Dragomir, an assistant professor in UNM's Department of Physics and Astronomy, and collaborators from Massachusetts Institute of Technology and University of Bern, analyzed the data in order to measure the periods and sizes of these planets.

After initially detecting the transits, Mireles and team had to confirm that these were actual planets and to determine which signal the star was coming from. The diagnostic tools with TESS indicated that the signals coming from the target site were indeed on point. With help from TESS-Follow-up Observing Program (TFOP) Subgroup 1 (SG1), a global network of professional and amateur astronomers with access to telescopes small and large, they observed and watched a transit happen thus confirming for the researchers that this planet is indeed on target. Another factor that Mireles and his team had to consider were the masses and sizes of the planets. In order to achieve this they substituted the velocity measurements to observe how much the host star wobbles because the host star will pull on the planet.

"When we got the measurements, we were seeing very little movement in the target star. So when you start, you could be responsible for what we were seeing. Those two things together pretty much ruled it out. At that point we were sure that we had two planets," Mireles stated.

The researchers found these two planets and the inner planet TOI-4600 b is 82.69 days with a radius that is around just under seven times Earth's radius. It is between the size of Neptune and Saturn. This planet, TOI-4600 b,has an estimated temperature of about 170 degrees Fahrenheit, which is hot, but colder than a lot of the planets that astronomers have found. The second planet found, TOI-4600 c, is about nine and a half times Earth's radius, meaning it is roughly Saturn sized. It initially transited only once the first time TESS observed the star before transiting a second time almost three years later.

"Once you have two transits, you have an idea of what the periods can be. It could be the 965 days separating them, half of that, a third, a quarter, etc. The shorter periods could be ruled out because TESS had observed the star for a long time, so it only left two periods: 965 days or half of that," explained Mireles. The researchers used a model developed by collaborator Hugh Osborn at the University of Bern to compare the possible orbital periods and determine which one was most likely, and found that half of 965, or 482.82 days to be precise, was more likely. TOI-4600 c's 482.82 day period makes it the longest-period planet found by TESS to date and with a temperature of around -110 degrees Fahrenheit, it is one of the coldest planets found by TESS.

Katharine Hesse, TOI & Vetting Lead at MIT, collaborated with Mireles and team on the data analysis from TESS. Hesse helped process and analyze the large amount of data and placed the system into the context of other multiple-planet systems that have been found by missions including TESS. The comparison of the TOI-4600 system with other discovered exoplanet systems helps explore features like the formation time and processes and helped the researchers begin to place this system in the broader context of exoplanet systems.

"The main thing is trying to uncover more about planet formation because based on what we know about the exoplanets we found, so far, nothing really looks like the solar system. The interesting thing is that we want to learn about this planet formation. We have over 5,000 exoplanets now, but none of these systems really look like the solar system. And so we want to find out how these different types of systems formed and migrated," Mireles said.

Mireles and researchers are interested in these findings because of the discovery of two long period giant planets, which is a configuration that astronomers don't often see, even though the solar system found had four giant long distances or a long period one. This prompts further research discussions and questions as Mireles points out, "We want to find out how these are formed? Are there other planets in this system? Does that tell us anything about how these giant planets affect smaller planets that might be in there or might not be in there and why they're not there? There's still things that we want to find out and that will tell us a lot about planet formation."

In closing, Mireles promotes a call to action for citizen scientists, and hobbyists in astronomy, to participate and get involved in this research discovery. On Monday, Oct. 16, there will be another possible transit opportunity coming up for those who are interested and want to observe it to further confirm that the period of the outer planet is indeed 482 days. People with even smaller telescopes could participate if they have the right tools. "There are definitely people that are citizen scientists or amateur astronomers that have their own telescopes and help us with all these observations. There is a group of people with access to telescopes that are essentially confirming that a transit event is occurring on the star of interest," said Mireles.

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New giant planet evidence of possible planetary collisions

A Neptune-sized planet denser than steel has been discovered by an international team of astronomers, who believe its composition could be the result of a giant planetary clash.

TOI-1853b's mass is almost twice that of any other similar-sized planet known and its density is incredibly high, meaning that it is made up of a larger fraction of rock than would typically be expected at that scale.

In the study, published today in Nature, scientists led by Luca Naponiello of University of Rome Tor Vergata and the University of Bristol suggest that this is the result of planetary collisions. These huge impacts would have removed some of the lighter atmosphere and water leaving a multitude of rock behind.

Senior Research Associate and co author Dr Phil Carter from Bristol's School of Physics, explained: "We have strong evidence for highly energetic collisions between planetary bodies in our solar system, such as the existence of Earth's Moon, and good evidence from a small number of exoplanets.

"We know that there is a huge diversity of planets in exoplanetary systems; many have no analog in our solar system but often have masses and compositions between that of the rocky planets and Neptune/Uranus (the ice giants).

"Our contribution to the study was to model extreme giant impacts that could potentially remove the lighter atmosphere and water/ice from the original larger planet in order to produce the extreme density measured.

"We found that the initial planetary body would likely have needed to be water-rich and suffer an extreme giant impact at a speed of greater than 75 km/s in order to produce TOI-1853b as it is observed."

This planet provides new evidence for the prevalence of giant impacts in the formation of planets throughout the galaxy. This discovery helps to connect theories for planet formation based on the solar system to the formation of exoplanets. The discovery of this extreme planet provides new insights into the formation and evolution of planetary systems.

Postgraduate student and co author Jingyao Dou said: "This planet is very surprising! Normally we expect planets forming with this much rock to become gas giants like Jupiter which have densities similar to water.

"TOI-1853b is the size of Neptune but has a density higher than steel. Our work shows that this can happen if the planet experienced extremely energetic planet-planet collisions during its formation.

"These collisions stripped away some of the lighter atmosphere and water leaving a substantially rock-enriched, high-density planet."

Now the team plan detailed follow-up observations of TOI-1853b to attempt to detect any residual atmosphere and examine its composition.

Associate Professor and co author Dr Zoë Leinhardt concluded: "We had not previously investigated such extreme giant impacts as they are not something we had expected. There is much work to be done to improve the material models that underlie our simulations, and to extend the range of extreme giant impacts modelled."

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Climate extremes hit stressed economies even harder

Economies already under stress respond more strongly to weather events like heat waves, river floods and tropical cyclones, a new study shows. A global economic crisis as during the Covid-19 pandemic strongly amplifies the price increases private households experience from the impacts of weather extremes, a team of researchers from the Potsdam Institute for Climate Impact Research (PIK) finds. The price impacts tripled in China, doubled in the United States and increased by a third in the European Union.

"The unprecedented societal interruptions during the Covid-19 pandemic of 2020 and onward took their toll on economic activity. Lockdowns disrupted supply chains and caused economic losses with implications for private households," lead author Robin Middelanis from PIK explains. "Global stress like this reduces the economic capacity to cope with additional shocks from weather extremes that put even more pressure on already stressed societies." For an individual climate disaster, impacts from local production losses can be flexibly reduced to a certain extent by the support of unaffected production sites in the economic network. Compensation mechanisms like this become more difficult when the world economy is stressed as a whole. The costs for households increase as products run short and become more expensive.

For their study published in the journal Environmental Research Letters, the researchers analyzed two scenarios, framed as a "stressed" economy and a counterfactual "unstressed" economy with full economic capacity. Under both scenarios, they simulated indirect economic impacts from direct local economic shocks caused by climate extremes like heat stress, river floods and tropical cyclones. For this, the interaction of more than 7,000 individual producing sectors and regional consumers connected through over 1.8 million trade links was computed on a daily time scale for the years 2020-2021. The study focuses on the resulting indirect price effects on private households for the three largest economies, the United States, China and the European Union.

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Researchers identify the link between memory and appetite in the human brain to explain obesity

Disrupted connections between memory and appetite regulating brain circuits are directly proportional to body mass index (BMI), notably in patients who suffer from disordered or overeating that can lead to obesity, such as binge eating disorder (BED), according to new research from the Perelman School of Medicine at the University of Pennsylvania. Published today in Nature, the research notes that individuals who are obese have impaired connections between the dorsolateral hippocampus (dlHPC) and the lateral hypothalamus (LH), which may impact their ability to control or regulate emotional responses when anticipating rewarding meals or treats.

"These findings underscore that some individual's brains can be fundamentally different in regions that increase the risk for obesity," senior author, Casey Halpern, MD, an associate professor of Neurosurgery and Chief of Stereotactic and Functional Neurosurgery at Penn Medicine and the Corporal Michael J. Crescenz Veterans Affairs Medical Center. "Conditions like disordered eating and obesity are a lot more complicated than simply managing self-control and eating healthier. What these individuals need is not more willpower, but the therapeutic equivalent of an electrician that can make right these connections inside their brain."

The dlHPC is located in the region of the brain that processes memory, and the LH is in the region of the brain that is responsible for keeping the body in a stable state, called homeostasis. Previous research has found an association with loss of function in the human hippocampus in individuals with obesity and related disordered eating, like BED. However, outside of imaging techniques such as magnetic resonance imaging (MRI), the role of the hippocampus has been difficult to study in humans with obesity and related eating disorders.

In this study, researchers were able to evaluate patients whose brains were already being monitored electrically in the Epilepsy Monitoring Unit. Researchers monitored brain activity as patients anticipated and then received a sweet treat (a chocolate milkshake). They found that both the dlHPC and the LH activated simultaneously when participants anticipated receiving the rewarding meal. These researchers confirmed using stimulation techniques pioneered by coauthors, Kai Miller, MD, PhD, and Dora Hermes Miller, PhD, from Mayo Clinic, that this specific zone of the hippocampus, the dlHPC, and LH exhibited extremely strong connectivity, as well.

In individuals with obesity, researchers found that the impairment of this hypothalamus-hippocampus circuit was directly proportional to their BMI. That is, in participants with a high BMI, the connection was even more disturbed.

To further validate the connection, Halpern's team used a technique called "brain clearing," to analyze brain tissue. The technique revealed melanin-concentrating hormone, a hormone known to regulate feeding behavior that is produced in the LH. They found the presence of MCH in the dlHPC, and nowhere else, confirming a link between the two regions.

"The hippocampus has never been targeted to treat obesity, or the disordered eating that can sometimes cause obesity," said Halpern. "We hope to be able to use this research to both identify which individuals who are likely to develop obesity later in life, and to develop novel therapies -- both invasive and not -- to help improve function of this critical circuit that seems to go awry in patients who are obese."

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Neptune's disappearing clouds linked to the solar cycle

Astronomers have uncovered a link between Neptune's shifting cloud abundance and the 11-year solar cycle, in which the waxing and waning of the Sun's entangled magnetic fields drives solar activity.

This discovery is based on three decades of Neptune observations captured by NASA's Hubble Space Telescope and the W. M. Keck Observatory in Hawaii, as well as data from the Lick Observatory in California.

The link between Neptune and solar activity is surprising to planetary scientists because Neptune is our solar system's farthest major planet and receives sunlight with about 0.1% of the intensity Earth receives. Yet Neptune's global cloudy weather seems to be driven by solar activity, and not the planet's four seasons, which each last approximately 40 years.

At present, the cloud coverage seen on Neptune is extremely low, with the exception of some clouds hovering over the giant planet's south pole. A University of California (UC) Berkeley-led team of astronomers discovered that the abundance of clouds normally seen at the icy giant's mid-latitudes started to fade in 2019.

"I was surprised by how quickly clouds disappeared on Neptune," said Imke de Pater, emeritus professor of astronomy at UC Berkeley and senior author of the study. "We essentially saw cloud activity drop within a few months," she said.

"Even now, four years later, the most recent images we took this past June still show the clouds haven't returned to their former levels," said Erandi Chavez, a graduate student at the Center for Astrophysics | Harvard-Smithsonian (CfA) in Cambridge, Massachusetts, who led the study when she was an undergraduate astronomy student at UC Berkeley. "This is extremely exciting and unexpected, especially since Neptune's previous period of low cloud activity was not nearly as dramatic and prolonged."

To monitor the evolution of Neptune's appearance, Chavez and her team analyzed Keck Observatory images taken from 2002 to 2022, the Hubble Space Telescope archival observations beginning in 1994, and data from the Lick Observatory in California from 2018 to 2019.

In recent years, the Keck observations have been complemented by images taken as part of the Twilight Zone program and by Hubble's Outer Planet Atmospheres Legacy (OPAL) program.

The images reveal an intriguing pattern between seasonal changes in Neptune's cloud cover and the solar cycle -- the period when the Sun's magnetic field flips every 11 years as it becomes more tangled like a ball of yarn. This is evident in the increasing number of sunspots and increasing solar flare activity. As the cycle progresses, the Sun's tempestuous behavior builds to a maximum, until the magnetic field beaks down and reverses polarity. Then the Sun settles back down to a minimum, only to start another cycle.

When it's stormy weather on the Sun, more intense ultraviolet (UV) radiation floods the solar system. The team found that two years after the solar cycle's peak, an increasing number of clouds appear on Neptune. The team further found a positive correlation between the number of clouds and the ice giant's brightness from the sunlight reflecting off it.

"These remarkable data give us the strongest evidence yet that Neptune's cloud cover correlates with the Sun's cycle," said de Pater. "Our findings support the theory that the Sun's UV rays, when strong enough, may be triggering a photochemical reaction that produces Neptune's clouds."

Scientists discovered the connection between the solar cycle and Neptune's cloudy weather pattern by looking at 2.5 cycles of cloud activity recorded over the 29-year span of Neptunian observations. During this time, the planet's reflectivity increased in 2002 then dimmed in 2007. Neptune became bright again in 2015, then darkened in 2020 to the lowest level ever observed, which is when most of the clouds went away.

The changes in Neptune's brightness caused by the Sun appear to go up and down relatively in sync with the coming and going of clouds on the planet. However there is a two-year time lag between the peak of the solar cycle and the abundance of clouds seen on Neptune. The chemical changes are caused by photochemistry, which happens high in Neptune's upper atmosphere and takes time to form clouds.

"It's fascinating to be able to use telescopes on Earth to study the climate of a world more than 2.5 billion miles away from us," said Carlos Alvarez, staff astronomer at Keck Observatory and co-author of the study. "Advances in technology and observations have enabled us to constrain Neptune's atmospheric models, which are key to understanding the correlation between the ice giant's climate and the solar cycle."

However, more work is necessary. For example, while an increase in UV sunlight could produce more clouds and haze, it could also darken them, thereby reducing Neptune's overall brightness. Storms on Neptune rising up from the deep atmosphere affect the cloud cover, but are not related to photochemically produced clouds, and hence may complicate correlation studies with the solar cycle. Continued observations of Neptune are also needed to see how long the current near-absence of clouds will last.

The research team continues to track Neptune's cloud activity. "We have seen more clouds in the most recent Keck images that were taken during the same time NASA's James Webb Space Telescope observed the planet; these clouds were in particular seen at northern latitudes and at high altitudes, as expected from the observed increase in the solar UV flux over the past approximately 2 years," said de Pater.

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Enhanced chemical weathering: A solution to the climate crisis?

The Earth is getting hotter and consequences have been made manifest this summer around the world. Looking back in geological history, global warming events are not uncommon: Around 56 million years ago, during the period known as the Paleocene-Eocene Thermal Maximum (PETM), the temperatures rose by an average of 5 to 8 degrees Celsius. This development was most likely linked to increased volcanism and the associated release of masses of carbon dioxide into the atmosphere. The higher temperatures persisted for about 200,000 years. Back in 2021, Professor Philip Pogge von Strandmann of Johannes Gutenberg University Mainz (JGU) had already investigated the effect that eventually led to global cooling and climatic recovery after the PETM warming.

In short: Rainwater combined with the atmospheric carbon dioxide, resulting in carbonic acid that caused enhanced weathering of rock, thus releasing calcium and magnesium. Rivers then transported the calcium, magnesium, and carbonic acid into the oceans where the calcium, magnesium -- and also the carbon dioxide -- came together to form insoluble limestone. "In other words, there is a feedback effect that helps control the climate. High temperatures accelerate the chemical rock weathering process, reducing the levels of carbon dioxide in the atmosphere, allowing the climate to recover," said Pogge von Strandmann.

Climate required twice as long to regenerate 40 million years ago

Climate warming occurred again 16 million years after the PETM during the Middle Eocene Climatic Optimum or MECO. Although volcanic activity resulted in the discharge of roughly the same amounts of carbon dioxide into the atmosphere as during the PETM, it took far longer for the climate to restabilize. The warming effect lasted for an immense 400,000 years, twice as long as in the PETM. Why was recovery so slow during that period?

In searching for an answer, Pogge von Strandmann and co-authors, including first author Alex Krause, began analyzing 40-million-year-old oceanic carbonates and clay minerals to compare the results with those for similar 56-million-year-old examples. "Just as during the PETM, there was also intensified weathering and erosion in the MECO. However, there was far less exposed rock on the Earth's surface 40 million years ago. Instead, the Earth was extensively covered by a global rainforest the soil of which largely consisted of clay minerals," explained the researcher. In contrast with rock, clay does not weather; in fact, it is actually the product of weathering. "So despite the high temperatures, the widespread clay soil prevented rocks from being effectively weathered, a process known as soil shielding," the geoscientist pointed out.

Enhanced weathering for climate protection

How can we use this knowledge in today's world? "We study paleoclimates to determine whether and how we can positively influence our present climate. One option might be to boost the chemical weathering of rock. To help achieve this, we could plough finely crushed rock into our fields," said Pogge von Strandmann. The fine-grained particles of rock would erode rapidly, resulting in the binding of atmospheric carbon dioxide, thus enabling the climate to recuperate. Negative emissions technologies (NETs) such as this involving the absorption of carbon dioxide are the subjects of intense research across the globe. At the same time, however, if the weathering results in the formation of clay, the effects of the process would be significantly less efficient, as Pogge von Strandmann has discovered. Clay retains the calcium and magnesium that would otherwise be delivered to the ocean. The carbon dioxide would continue to flow into the oceans, but it would not be bound there and would be able to escape back into the atmosphere. In this case, the weathering effect would have next to no influence on the climate.

If the rock particles fully dissolve as a result of weathering, the enhanced weathering concept would turn out to be 100 percent efficient. However, if all the weathered materials were turned into clay, this would in its turn completely nullify the effect. In reality, the actual outcome would probably be somewhere between the two extremes: While there was enhanced erosion of rock in the PETM so that the climate normalized more rapidly, clay formation was predominant during the MECO. The extent to which the crushed rock dissolves and how much of it is preserved as clay depends on a range of local factors, such as the globally pre-existing levels of clay and rock. So in order to establish whether the process of enhanced weathering is a viable approach, it would first be necessary to find out how much clay is formed during the weathering process at each potential location.

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Three-eyed distant relative of insects and crustaceans reveals amazing detail of early animal evolution

A team from the University of Leicester, Yunnan Key Laboratory for Palaeobiology and the Institute of Palaeontology at Yunnan University, Chengjiang Fossil Museum, and the Natural History Museum in London, have redescribed a unique fossil animal from rocks nearly 520 million years old that fills in a gap in our understanding of the evolution of animals known as arthropods.

The animal, which has the scientific name Kylinxia, was imaged using a CT scanner which revealed its soft anatomy buried in the rock. The size of a large shrimp, its surprising features include three eyes on the head and a pair of fearsome limbs presumably used to catch prey.

The study is published this week in the high impact journal Current Biology.

Fossils of many kinds of marine animals first appear in rocks from about half a billion years ago and signal a time when complex ecosystems were developing in the world's oceans. One of the key localities for such fossils is the area around the town of Chengjiang in southern China, where the fossils in this study were collected by the Chinese team. The fossils were recovered from the Cambrian Chengjiang biota of China's Yunnan Province, from which over 250 species of exceptionally preserved fossil organisms have been described.

The new find is important for deciphering the history of arthropods. These are animals whose bodies are divided into segments, most of which bear a paired of jointed limbs, like crabs, lobsters, insects, and spiders.

Although there are plenty of arthropods in the fossil record -- most famously the trilobites -- the vast majority only preserve their hard skeletons. Because the new Chinese material is preserved nearly complete, the team were able to image the head of Kylinxia, identifying six segments: the front one bearing eyes, the second with a pair of large grasping limbs, and the other four each bearing a pair of jointed limbs.

Lead author of the study Robert O'Flynn, a PhD student at the University of Leicester School of Geography, Geology and the Environment, said: "The preservation of the fossil animal is amazing. After CT-scanning we can digitally turn it around and literally stare into the face of something that was alive over 500 million years ago. As we spun the animal around, we could see that its head possesses six segments, just as in many living arthropods."

Professor Mark Williams, Robert's primary supervisor at the University of Leicester, said: "Kylinxia, and the Chengjiang biota whence it came, are instrumental to building our understanding of early euarthropod evolution. I like to think that similar discoveries will continue to be made by Robert."

Professor Yu Liu from the Yunnan Key Laboratory for Palaeobiology said: "Robert and I were examining the micro-CT data as part of his doctoral thesis in the hope of refining and correcting previous interpretation of head structures in this genus, Kylinxia. Amazingly, we found that its head is composed of six segments, as in, e.g., insects."

Dr Greg Edgecombe from the Natural History Museum added: "Most of our theories on how the head of arthropods evolved were based on these early-branching species having fewer segments than living species. Discovering two previously undetected pairs of legs in Kylinxia suggests that living arthropods inherited a six-segmented head from an ancestor at least 518 million years ago."

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Common origin behind major childhood allergies

Several major childhood allergies may all stem from the community of bacteria living in our gut, according to a new study led by researchers at the University of British Columbia and BC Children's Hospital.

The research, published in Nature Communications, identifies gut microbiome features and early life influences that are associated with children developing any of four common allergies -- eczema, asthma, food allergy and/or hay fever. The findings could lead to methods of predicting whether a child will develop allergies, and ways to prevent them from developing at all.

"We're seeing more and more children and families seeking help at the emergency department due to allergies," said Dr. Stuart Turvey, professor in the department of pediatrics at UBC and an investigator at BC Children's Hospital Research Institute, and co-senior author on the study. "Hundreds of millions of children worldwide suffer from allergies, including one in three children in Canada, and it's important to understand why this is happening and how it can be prevented."

The study is one of the first to examine four distinct school-aged pediatric allergies at once. While these allergic diseases each have unique symptoms, the Turvey lab was curious whether they might have a common origin linked to the infant gut microbiota composition.

"These are technically different diagnoses, each with their own list of symptoms, so most researchers tend to study them individually," says Dr. Charisse Petersen, co-senior author on the paper and postdoctoral fellow in the Turvey lab. "But when you look at what is going wrong at a cellular level, they actually have a lot in common."

For the study, researchers examined clinical assessments from 1,115 children who were tracked from birth to age five. Roughly half of the children (523) had no evidence of allergies at any time, while more than half (592) were diagnosed with one or more allergic disorders by an expert physician. The researchers evaluated the children's microbiomes from stool samples collected at clinical visits at three months and one year of age.

The stool samples revealed a bacterial signature that was associated with the children developing any of the four allergies by five years of age. The bacterial signature is a hallmark of dysbiosis, or an imbalanced gut microbiota, that likely resulted in a compromised intestinal lining and an elevated inflammatory response within the gut.

"Typically, our bodies tolerate the millions of bacteria living in our guts because they do so many good things for our health. Some of the ways we tolerate them are by keeping a strong barrier between them and our immune cells and by limiting inflammatory signals that would call those immune cells into action," says Courtney Hoskinson, a PhD candidate at UBC and first author on the paper. "We found a common breakdown in these mechanisms in babies prior to the development of allergies."

Many factors can shape the infant gut microbiota, including diet, how we are born, where we live, and our exposure to antibiotics. For example, antibiotics may wipe out sensitive bacteria, while breastfeeding tends to replenish and provide necessary food for bacteria in the infant gut. The researchers examined how these types of influences affected the balance of gut microbiota and the development of allergies.

"There are a lot of potential insights from this robust analysis," says Dr. Turvey. "From these data we can see that factors such as antibiotic usage in the first year of life are more likely to result in later allergic disorders, while breastfeeding for the first six months is protective. This was universal to all the allergic disorders we studied."

Now the researchers hope to leverage the findings to inform treatments that correct an imbalanced gut microbiota and could potentially prevent allergies from developing.

"Developing therapies that change these interactions during infancy may therefore prevent the development of all sorts of allergic diseases in childhood, which often last a lifetime," says Dr. Turvey.

The research is part of the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study that recruited families through BC Children's Hospital and BC Women's Hospital + Health Centre and other pediatric hospitals across Canada. Since launching in 2008, the team of Canadian researchers has tracked the health, growth and environments of kids from birth and made important discoveries about how asthma and allergies develop.

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How being in space impairs astronauts' immune system

A new study led by researchers at Karolinska Institutet in Sweden has examined how T cells of the immune system are affected by weightlessness. The results, which are published in the journal Science Advances, could explain why astronauts' T cells become less active and less effective at fighting infection.

The next steps in the exploration of space are human missions to the moon and to Mars. Space is an extremely hostile environment that poses threats to human health. One such threat is changes to the immune system that occur in astronauts while in space and that persist after their return to Earth. This immune deficiency can leave them more vulnerable to infection and lead to the reactivation of latent viruses in the body.

"If astronauts are to be able to undergo safe space missions, we need to understand how their immune systems are affected and try to find ways to counter harmful changes to it," says study leader Lisa Westerberg, principal researcher at the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet. "We've now been able to investigate what happens to T cells, which are a key component of the immune system, when exposed to weightless conditions."

In the study, the researchers have tried to simulate weightlessness in space using a method called dry immersion. This involves a custom-made waterbed that tricks the body into thinking it is in a weightless state. The researchers examined T cells in the blood of eight healthy individuals for three weeks of exposure to simulated weightlessness. Blood analyses were performed before the experiment started, at 7, 14 and 21 days after the start, and at 7 days after the experiment ended.

They found that the T cells significantly changed their gene expression -- that is to say, which genes were active and which were not -- after 7 and 14 days of weightlessness and that the cells became more immature in their genetic programme. The greatest effect was seen after 14 days.

"The T cells began to resemble more so-called naïve T cells, which have not yet encountered any intruders. This could mean that they take longer to be activated and thus become less effective at fighting tumour cells and infections. Our results can pave the way for new treatments that reverse these changes to the immune cells' genetic programme," says Carlos Gallardo Dodd, PhD student at the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet and shared first author with researchers Christian Oertlin and Julien Record at the same department.

After 21 days, the T cells had "adapted" their gene expression to weightlessness so that it had almost returned to normal, but analyses carried out seven days after the experiment ended showed that the cells had regained some of the changes.

The researchers now plan to use Esrange Space Centre's sounding rocket platform in Kiruna, Sweden, to study how T cells behave in weightless conditions and how their function is affected.

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Microplastics infiltrate all systems of body, cause behavioral changes

Plastics -- in particular, microplastics -- are among the most pervasive pollutants on the planet, finding their way into the air, water systems and food chains around the world. While the prevalence of microplastics in the environment is well known -- as are their negative impacts on marine organisms -- few studies have examined the potential health impacts on mammals, prompting University of Rhode Island Professor Jaime Ross' new study.

Ross and her team focused on neurobehavioral effects and inflammatory response to exposure to microplastics, as well as the accumulation of microplastics in tissues, including the brain. They have found that the infiltration of microplastics was as widespread in the body as it is in the environment, leading to behavioral changes, especially in older test subjects.

"Current research suggests that these microplastics are transported throughout the environment and can accumulate in human tissues; however, research on the health effects of microplastics, especially in mammals, is still very limited," said Ross, an assistant professor of biomedical and pharmaceutical sciences at the Ryan Institute for Neuroscience and the College of Pharmacy. "This has led our group to explore the biological and cognitive consequences of exposure to microplastics."

Ross' team -- which includes Research Assistant Professor Giuseppe Coppotelli, biomedical and pharmaceutical sciences graduate student Lauren Gaspar, and Interdisciplinary Neuroscience Program graduate student Sydney Bartman -- exposed young and old mice to varying levels of microplastics in drinking water over the course of three weeks. They found that microplastic exposure induces both behavioral changes and alterations in immune markers in liver and brain tissues. The study mice began to move and behave peculiarly, exhibiting behaviors akin to dementia in humans. The results were even more profound in older animals.

"To us, this was striking. These were not high doses of microplastics, but in only a short period of time, we saw these changes," Ross said. "Nobody really understands the life cycle of these microplastics in the body, so part of what we want to address is the question of what happens as you get older. Are you more susceptible to systemic inflammation from these microplastics as you age? Can your body get rid of them as easily? Do your cells respond differently to these toxins?"

To understand the physiological systems that may be contributing to these changes in behavior, Ross' team investigated how widespread the microplastic exposure was in the body, dissecting several major tissues including the brain, liver, kidney, gastrointestinal tract, heart, spleen and lungs. The researchers found that the particles had begun to bioaccumulate in every organ, including the brain, as well as in bodily waste.

"Given that in this study the microplastics were delivered orally via drinking water, detection in tissues such as the gastrointestinal tract, which is a major part of the digestive system, or in the liver and kidneys was always probable," Ross said. "The detection of microplastics in tissues such as the heart and lungs, however, suggests that the microplastics are going beyond the digestive system and likely undergoing systemic circulation. The brain blood barrier is supposed to be very difficult to permeate. It is a protective mechanism against viruses and bacteria, yet these particles were able to get in there. It was actually deep in the brain tissue."

That brain infiltration also may cause a decrease in glial fibrillary acidic protein (called "GFAP"), a protein that supports many cell processes in the brain, results have shown. "A decrease in GFAP has been associated with early stages of some neurodegenerative diseases, including mouse models of Alzheimer's disease, as well as depression," Ross said. "We were very surprised to see that the microplastics could induce altered GFAP signaling."

She intends to investigate this finding further in future work. "We want to understand how plastics may change the ability for the brain to maintain its homeostasis or how exposure may lead to neurological disorders and diseases, such as Alzheimer's disease," she said.

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Historic red tide event of 2020 fueled by plankton super swimmers

A major red tide event occurred in waters off Southern California in the spring of 2020, resulting in dazzling displays of bioluminescence along the coast. The spectacle was caused by exceedingly high densities of Lingulodinium polyedra (L. polyedra),a plankton species renowned for its ability to emit a neon blue glow. While the red tide captured the public's attention and made global headlines, the event was also a harmful algal bloom. Toxins were detected at the height of the bloom that had the potential to harm marine life, and dissolved oxygen levels dropped to near-zero as the extreme biomass of the red tide decomposed. This lack of oxygen led to fish die-offs and other destructive impacts on local ecosystems.

Now, for the first time, a study led by scientists at UC San Diego's Scripps Institution of Oceanography and Jacobs School of Engineering has pinpointed how this plankton species -- a dinoflagellate -- was able to create such an exceptionally dense bloom. The answer lies in dinoflagellates' remarkable ability to swim, which lends them a competitive advantage over other species of phytoplankton. According to the authors, this swimming ability can lead to the formation of dense blooms, including those of the bioluminescent variety.

"The idea that vertical swimming gives dinoflagellates a competitive advantage actually goes back more than half a century, but only now do we have the technology to conclusively prove it in the field," said oceanographer Drew Lucas, senior author of the paper and an associate professor at Scripps Oceanography and the Department of Mechanical and Aerospace Engineering at UC San Diego.

Lucas and former graduate student Bofu Zheng led the work alongside several colleagues in the midst of the red tide event in April and May 2020. The researchers seized the opportunity to deploy sophisticated ocean instruments off the coast of San Diego, resulting in unprecedented measurements. The effort was made possible with funding provided by the Southern California Coastal Ocean Observing System (SCCOOS) through an award by the National Oceanic and Atmospheric Administration (NOAA). The team's findings were published in the Aug. 28 issue of the Proceedings of the National Academy of Sciences, showcased as the cover story.

The dinoflagellates -- L. polyedra specifically -- were shown to be highly mobile, swimming upward during the day to photosynthesize and downward at night to access a deep nutrient pool. This resulted in the intensified ruddy coloration of the water at the surface, hence the term "red tide," seen most prominently in the afternoon. A large population of the dinoflagellates was documented making the downward journey at night, though a portion remained near the surface waters, leading to nighttime displays of bioluminescence. The authors found that this vertical migration is what allowed the dinoflagellates to outgrow their non-mobile competitors, including other species of phytoplankton.

The study validates a 50-year-old hypothesis originally presented by Scripps Oceanography biological oceanographer Richard "Dick" Eppley. He and colleagues posited that the vertical migration of dinoflagellates was linked to harmful algal blooms, which have been documented off Southern California for at least 120 years. Extensive lab research was conducted to support this idea, but it had never been tested in the field until the 2020 event.

As in many dinoflagellate species, L. polyedra is endowed with a pair of flagella -- whip-like appendages that propel the single-celled organism through the water. In addition to its ability to swim, L. polyedra is remarkably fast, with a maximum swimming speed of up to 10 body lengths per second for almost 24 hours.

"In the plankton world, they are Michael Phelps," said Lucas, describing the dinoflagellates. "For comparison, fast-burst swimming in species like bluefin tuna or shortfin mako is around 9-10 body lengths per second, but only for very short periods. Their exceptional swimming allows L. polyedra to dive to cold depths where they can take up nutrients, allowing these organisms to really bloom and explode in population."

The team used the Wirewalker -- an autonomous, ocean-wave-powered vertical profiling system that was developed at Scripps Oceanography -- to continuously measure physical and biochemical conditions from the sea surface to the seafloor, reaching a depth of 100 meters (300 feet). Powered by wave energy, the instrument moves up and down a mooring line attached to a buoy, while taking measurements of temperature, salinity, depth, sunlight levels, chlorophyll fluorescence, and nitrate concentrations. They also captured near-surface images of the bloom using an Imaging FlowCytobot (IFCB), a robotic microscope installed on an offshore mooring; this site is now part of a larger IFCB network overseen by SCCOOS.

Data and images collected by these instruments validated Eppley's original hypothesis, showing that indeed L. polyedra descended at dusk, reaching a maximum depth of about 30-40 meters (100-130 feet) after 18 to 24 hours of swimming. While in the deep, the dinoflagellates would take up nitrate, which acts as a growth nutrient for plankton, before returning to the surface around noon to photosynthesize during maximum sunlight.

The growth of phytoplankton biomass, or the "bloom," correlated with proportional decreases in nitrate concentrations at depth, linking the important role that swimming phytoplankton have in the development of certain types of red tides. On cloudy days, the subsurface vertical migration was much less apparent, suggesting that the intensity of sunlight is an important trigger for vertical migration.

Lead author Zheng, now a postdoctoral investigator at Woods Hole Oceanographic Institution (WHOI), was impressed by the many advanced functions of the dinoflagellates, which are comparable in size to the diameter of a human hair.

"These single-celled organisms, namely L. polyedra, are so functionally complex and amazing," said Zheng. "In addition to their swimming speed, which is far beyond human limits, they can coordinate their behavior according to the day-night cycle by migrating down at night and coming back to the ocean surface during the day; they can produce spectacular bioluminescence; they can photosynthesize; they can even prey on organisms that are smaller than them."

The researchers also looked at long-term ocean monitoring data captured by the California Cooperative Oceanic Fisheries Investigations (CalCOFI), and long-term mooring data maintained by the Ocean Time-Series Group at Scripps Oceanography to see other consequences from the bloom. Looking at more than 70 years of climate data, the results showed that the bloom created physical and chemical conditions in the water column that deviated from the norm, showing the potential for massive blooms to alter characteristics of the coastal ocean.

Study co-author and SCCOOS director Clarissa Anderson said this research stands out for its use of novel ocean technologies, which allowed for unparalleled measurements of how phytoplankton respond to small-scale changes in the coastal ocean, as well as calculations of nutrient uptake by dinoflagellates at such fine scales. She also noted the importance of long-term observations as being key to any future efforts to better understand harmful algal blooms.

"The more we understand complex mechanisms that allow a particular species or population of plankton to thrive and persist, the better we can predict runaway events like the 2020 red tide that lasted much longer than theory might dictate," said Anderson, who is also a biological oceanographer at Scripps Oceanography. "With longer time series of rapid change in coastal nutrient delivery, circulation, light regimes, and algal toxins, we could build more accurate dynamical models for predicting plankton blooms, including those that turn harmful."

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The physics of fat droplets reveal DNA danger

Fat is a normal and necessary part of the body. Fat cells store and release energy, as well as play significant roles in hormonal regulation and immunity.

In recent decades, a concerning rise in metabolic illnesses -- such as cardiovascular disease, high blood pressure and diabetes -- has focused scientific attention on the biology and chemistry of fat, resulting in a wealth of information about how fat cells work.

But fat cells and their metabolic activities are only part of the story.

Fat-filled lipid droplets, tiny spheres of fat many times smaller than fat cells, are a growing subject of scientific interest. Found inside many different cell types, these lipid particles have long been little understood. Studies have begun to illuminate these droplets' participation in metabolic functions and cellular protection, but we still know next to nothing about the physical nature of fat.

Now, researchers at the University of Pennsylvania School of Engineering and Applied Science have looked beyond biochemistry to publish groundbreaking work on the physics of these droplets, revealing them to be a potential threat to a cell's nucleus. In the August issue of the Journal of Cell Biology, they are the first to discover fat-filled lipid droplets' surprising capability to indent and puncture the nucleus, the organelle which contains and regulates a cell's DNA.

The stakes of their findings are high: a ruptured nucleus can lead to elevated DNA damage that is characteristic of many diseases, including cancer.

The study was led by Dennis E. Discher, Robert D. Bent Professor in the Department of Chemical and Biomolecular Engineering, Irena Ivanovska, Ph.D. Research Associate in Penn's Molecular and Cell Biophysics Lab, and Michael Tobin, Ph.D. Candidate in the Department of Bioengineering.

"Intuitively, people think of fat as soft," says Discher. "And on a cellular level it is. But at this small size of droplet -- measuring just a few microns rather than the hundreds of microns of a mature fat cell -- it stops being soft. Its shape has a much higher curvature, bending other objects very sharply. This changes its physics in the cell. It can deform. It can damage. It can rupture."

"Imagine," adds Ivanovska, "trying to pop a balloon with your fist. Impossible. You can deform the balloon, but you won't puncture it. Now imagine trying to pop it with a pen. That's the difference between a fat cell and a cell with small fat droplets in the body. It's a fundamental physical difference, not a metabolic one."

The team's research reframes scientific inquiry into fat, underlining that fat's role in the body is much more than just a number on the scales.

"This isn't fat canonically conceived," says Tobin. "This is about how fat works at scales smaller than a cell and poses physical risks to cellular components, even at the level of DNA."

The team's work builds on a decade of foundational research, including leading contributions by Ivanovska, into the behaviors of nuclear proteins that give the nucleus its protective structural qualities. These proteins are dynamic, shifting levels to respond to their mechanical environments and provide what the nucleus needs to maintain its integrity.

"There's a constant process of repair to DNA damage that goes on in cells," says Ivanovska. "For this to happen, the nucleus needs to have enough DNA repair proteins. If a nucleus is ruptured, these proteins scatter and cannot repair damage in a timely manner. This causes DNA damage accumulation and can potentially result in a cancer cell."

A cell lives in a dynamic physical and mechanical environment where things can and do go wrong. But it also has an army of molecular helpers always working to maintain and repair it.

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Researcher finds inspiration from spider webs and beetles to harvest fresh water from thin air

A team of researchers is designing novel systems to capture water vapour in the air and turn it into liquid.

University of Waterloo professor Michael Tam and his PhD students Yi Wang and Weinan Zhao have developed sponges or membranes with a large surface area that continually capture moisture from their surrounding environment.

Traditionally, fresh water for consumption is collected from rivers, lakes, groundwater, and oceans (with treatment). The current technologies Dr. Tam is developing are inspired by nature to harvest water from alternative sources as the world is facing a serious challenge with freshwater scarcity.

"A spider's web is an engineering marvel," said Tam, a University Research Chair in the field of functional colloids and sustainable nanomaterials. "Water is efficiently captured by the web. The spider doesn't need to go to the river to drink, as it traps moisture from the air."

Similarly, Namib desert beetles have no easy access to water but acquire water from thin air by leaning into the wind to capture droplets of water from the fog with their textured body armour. This allows the moisture to accumulate and drip into their mouths.

Tam and his research group are engaged in biomimetic surface engineering for sustainable water harvesting. One technology Tam is designing is called atmospheric water harvesting. To mimic the beetle's unique surface structure, Tam's research group is designing a similar surface structure using a cellulose-stabilized wax emulsion to fabricate surfaces that attract tiny water droplets while swiftly releasing larger ones.

Tam is working with net zero carbon materials, such as natural and plant-based materials, to develop sustainable technologies. His research group is developing technologies that capture and repel water droplets by harnessing the power of interfacial science and nanotechnology. He has successfully developed superhydrophobic and waterproof paper. He is also engineering a smart and tunable surface that captures water from the air and dehumidifies it with minimal energy consumption.

The next step is to develop a scalable process to engineer such surfaces.

Solar evaporation systems directly harvest solar energy, absorbing water and generating fresh collectible vapour through evaporation. Unique mushroom structures inspired the smart biomimetic structural designs for solar evaporation.

The proposed freshwater generation systems are inexpensive, energy-efficient, and environmentally friendly.

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Millions of carbon credits are generated by overestimating forest preservation, study finds

The majority of carbon offset schemes are significantly overestimating the levels of deforestation they are preventing, according to a study published today in Science.

This means that many of the "carbon credits" bought by companies to balance out emissions are not tied to real-world forest preservation as claimed.

An international team of scientists and economists led by the University of Cambridge and VU Amsterdam found that millions of carbon credits are based on crude calculations that inflate the conservation successes of voluntary REDD+ projects.

Consequently, many tonnes of greenhouse gas emissions considered "offset" by trees that would not otherwise exist have, in fact, only added to our planetary carbon debt, say researchers.

REDD+ schemes generate carbon credits by investing in the protection of sections of the world's most important forests -- from the Congo to the Amazon basin. These credits represent the carbon that will no longer be released through deforestation.

Organisations and individuals can then offset their own carbon footprint by purchasing credits equivalent to a given quantity of emissions.

Carbon credit markets have exploded in recent years. Over 150 million credits originated from voluntary REDD+ projects in 2021, with a value of US $1.3 billion. Some companies use carbon offsetting to claim progress towards "net zero" while doing little to reduce greenhouse gases, say researchers.

The team behind the latest study argue that the booming trade in carbon credits may already be a type of "lemons market": where buyers have no way of distinguishing quality, so some sellers flood the market with bad products, leading to a breakdown of trust and ultimately market collapse.

"Carbon credits provide major polluters with some semblance of climate credentials. Yet we can see that claims of saving vast swathes of forest from the chainsaw to balance emissions are overblown," said study senior author Prof Andreas Kontoleon, from Cambridge's Department of Land Economy.

"These carbon credits are essentially predicting whether someone will chop down a tree, and selling that prediction. If you exaggerate or get it wrong, intentionally or not, you are selling hot air."

Kontoleon points out that overestimations of forest preservation have allowed the number of carbon credits on the market to keep rising, which in turn supresses the prices.

"Potential buyers benefit from consistently low prices created by the flood of credits. It means that companies can tick their net zero box at the lowest possible cost," he said.

REDD+ is a loose acronym for "Reducing emissions from deforestation and forest degradation in developing countries." Currently, credits from voluntary "avoided deforestation" projects are issued based on predictions of tree loss that would have occurred without the REDD+ scheme.

Researchers say these calculations -- which take historical deforestation averages or trends, sometimes from over a decade ago, across a wide region that usually includes the REDD+ site -- are often far too simplistic.

The latest study looked in detail at 18 REDD+ projects in five tropical countries: Peru, Colombia, Cambodia, Tanzania and the Democratic Republic of Congo.*

The research team took a "counterfactual" approach. They identified existing areas of forest within a given region that closely resemble each particular REDD+ project -- from matching levels of forest cover and soil fertility to similar records of mining and deforestation.

"We used real-world comparison sites to show what each REDD+ forest project would most probably look like now, rather than relying on extrapolations of historical data that ignore a wide range of factors, from policy changes to market forces," said lead author Dr Thales West, a Fellow of the Centre for Environment, Energy and Natural Resource Governance at Cambridge, now based at VU Amsterdam.

Of the 18 REDD+ projects, only one had underestimated its deforestation rates, and one had predicted deforestation levels similar to its comparison site. The other 16 projects all claimed far more deforestation would have taken place than their comparison sites suggested.

In fact, of the 89 million carbon credits expected to be generated by these 18 REDD+ sites in 2020, some 68% of them -- over 60 million credits -- would have come from projects that barely reduced deforestation, if at all, according to the study.

Even the remaining 32% of carbon credits originated from REDD+ projects that had not conserved forest to the levels claimed by the project developers.

The researchers produced carbon credit calculations that replaced deforestation levels as predicted by each REDD+ project with the levels of real-world forest cover from comparison sites.

They estimate that only 5.4 million carbon credits were linked to additional cuts in carbon emissions created by preserved trees -- the entire basis on which credits are sold. This suggests that only 6% of the total carbon credits produced by all 18 REDD+ projects in 2020 are valid.

As of November 2021, at least 14.6 million carbon credits from the 18 REDD+ projects had been purchased around the world to offset greenhouse gas emissions. "These projects have already been used to offset almost three times more carbon than they have actually mitigated through forest preservation," said Kontoleon. "And that's with over 47 million credits still available in the market."

The researchers highlight four possible -- and overlapping -- reasons why carbon credit schemes might be overestimating their effectiveness so dramatically.

One is that use of historical trends is simply highly inaccurate. Moreover, projects may be located where conservation is most likely to succeed regardless. Thirdly, certification rules currently require fixed periods for projections, so adapting to changes in deforestation rates is difficult.

Lastly, the researchers also highlight clear risks that methods of predicting deforestation may be "opportunistically inflated" to maximise revenues from credit sales.

"There are perverse incentives to generate huge numbers of carbon credits, and at the moment the market is essentially unregulated. Watchdog agencies are being created, but many of those involved are also linked to carbon credit certification agencies -- so they will be marking their own homework," added Kontoleon.

"The industry needs to work on closing loopholes that might allow bad faith actors to exploit offset markets. It must develop far more sophisticated and transparent methods of quantifying the amount of preserved forest to become a trusted marketplace."

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Wastewater pipe dig reveals 'fossil treasure trove'

A new New Zealand Journal of Geology and Geophysics paper out today describes the 266 fossil species as one of the richest and most diverse groups of three-million-year-old fauna ever found in New Zealand. At least ten previously unknown species will be described and named in future research.

Fossil treasure trove from Auckland's Mangere Wastewater Treatment Plant

In 2020, when Auckland's Watercare were excavating two huge vertical shafts for a major upgrade of the major pipeline that brings raw sewage for treatment from the central city they dug through an ancient shell bed. Auckland paleontologist Bruce Hayward likened it to "finding gold right on your door step." Once they were informed of the fossil deposit's significance, Watercare and their contractors were eager to help and a huge heap of shelly sand was dumped in a nearby paddock so that paleontologists could search through it over many months. Watercare also funded two paleontology graduate students, working under the supervision of Auckland Museum curator Dr Wilma Blom, to painstakingly sift through the heap for many weeks. As a result, it is estimated that over 300,000 fossils were examined and several thousand have been returned in the museum as a record of this "once-in-a-lifetime find."

"Detailed identification of the fossils shows that they were deposited between 3 and 3.7 million years ago in a subtidal channel in an early version of the modern Manukau Harbour," said Dr Hayward. "At that time, sea level was slightly higher than it is today as the world was also several degrees warmer than now. As a result, the fossils include a number of subtropical species, whose relatives today live in the warmer waters around the Kermadec and Norfolk islands. At least ten previously unknown species are present and will be described and named in future work."

In their scientific paper that appeared this week in the New Zealand Journal of Geology and Geophysics, the five authors record 266 different fossil species, making it the richest and most diverse fauna of its age ever found in New Zealand. "What is surprising," says lead author Dr Hayward "is that the fauna contains fossils that lived in many different environments that have been brought together in the ancient marine channel by wave action and strong tidal currents. It includes ten specimens of the iconic NZ flax snail that must have lived on the adjacent land and been washed down into the sea by storm runoff. These are by far the oldest known flax snails in the world. Most of the fossils lived on the sea floor, some in brackish estuaries, others attached to hard rocky shorelines and still more have been carried in from offshore of the exposed west coast at the time."

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Scientists invent micrometers-thin battery charged by saline solution that could power smart contact lenses

Scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed a flexible battery as thin as a human cornea, which stores electricity when it is immersed in saline solution, and which could one day power smart contact lenses.

Smart contact lenses are high-tech contact lenses capable of displaying visible information on our corneas and can be used to access augmented reality. Current uses include helping to correct vision, monitoring wearers' health, and flagging and treating diseases for people with chronic health conditions such as diabetes and glaucoma. In the future, smart contact lenses could be developed to record and transmit everything a wearer sees and hears to cloud-based data storage.

However, to reach this future potential a safe and suitable battery needs to be developed to power them. Existing rechargeable batteries rely on wires or induction coils that contain metal and are unsuitable for use in the human eye, as they are uncomfortable and present risks to the user.

The NTU-developed battery is made of biocompatible materials and does not contain wires or toxic heavy metals, such as those in lithium-ion batteries or wireless charging systems. It has a glucose-based coating that reacts with the sodium and chloride ions in the saline solution surrounding it, while the water the battery contains serves as the 'wire' or 'circuitry' for electricity to be generated.

The battery could also be powered by human tears as they contain sodium and potassium ions, at a lower concentration. Testing the current battery with a simulated tear solution, the researchers showed that the battery's life would be extended an additional hour for every twelve-hour wearing cycle it is used. The battery can also be charged conventionally by an external power supply.

Associate Professor Lee Seok Woo, from NTU's School of Electrical and Electronic Engineering (EEE), who led the study, said: "This research began with a simple question: could contact lens batteries be recharged with our tears? There were similar examples for self-charging batteries, such as those for wearable technology that are powered by human perspiration.

"However, previous techniques for lens batteries were not perfect as one side of the battery electrode was charged and the other was not. Our approach can charge both electrodes of a battery through a unique combination of enzymatic reaction and self-reduction reaction. Besides the charging mechanism, it relies on just glucose and water to generate electricity, both of which are safe to humans and would be less harmful to the environment when disposed, compared to conventional batteries."

Co-first author Dr Yun Jeonghun, a research fellow from NTU's EEE said: "The most common battery charging system for smart contact lenses requires metal electrodes in the lens, which are harmful if they are exposed to the naked human eye. Meanwhile, another mode of powering lenses, induction charging, requires a coil to be in the lens to transmit power, much like wireless charging pad for a smartphone. Our tear-based battery eliminates the two potential concerns that these two methods pose, while also freeing up space for further innovation in the development smart contact lenses."

Highlighting the significance of the work done by the research team, NTU School of Mechanical & Aerospace Engineering Associate Professor Murukeshan Vadakke Matham, who specialises in biomedical and nanoscale optics and was not involved in the study, said: "As this battery is based on glucose oxidase, which occurs naturally in humans and powered by chloride and sodium ions, such as those in our tears, they should be compatible and suitable for human usage. Besides that, the smart contact lenses industry has been looking for a thin, biocompatible battery that does not contain heavy metals, and this invention could help further their development to meet some unmet needs of the industry."

The research team has filed for a patent through NTUitive, NTU's innovation and enterprise company. They are also working towards commercialising their invention.

The findings were published in the scientific journal Nano Energy in June.

Cry me a current

The team demonstrated their invention using a simulated human eye. The battery, which is about 0.5 millimetres-thin generates electrical power by reacting with the basal tears -- the constant tears that create a thin film over our eyeballs -- for the devices embedded within the lenses to function.

The flexible and flat battery discharges electricity through a process called reduction when its glucose oxidase coating reacts with the sodium and chloride ions in the tears, generating power and current within the contact lenses.

The team demonstrated that the battery could produce a current of 45 microamperes and a maximum power of 201 microwatts, which would be sufficient to power a smart contact lens.

Laboratory tests showed that the battery could be charged and discharged up to 200 times. Typical lithium-ion batteries have a lifespan of 300 to 500 charging cycles.

The team recommends that the battery should be placed for at least eight hours in a suitable solution that contains a high quantity of glucose, sodium and potassium ions, to be charged while the user is asleep.

Co-first author Miss Li Zongkang, a PhD student from NTU's EEE said: "Although wireless power transmission and supercapacitors supply high power, their integration presents a significant challenge due to the limited amount of space in the lens. By combining the battery and biofuel cell into a single component, the battery can charge itself without the need for additional space for wired or wireless components. Furthermore, the electrodes placed at the outer side of the contact lens ensures that the vision of the eye cannot be obstructed."

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