Scientists pin down the origins of the moon's tenuous atmosphere

While the moon lacks any breathable air, it does host a barely-there atmosphere. Since the 1980s, astronomers have observed a very thin layer of atoms bouncing over the moon's surface. This delicate atmosphere -- technically known as an "exosphere" -- is likely a product of some kind of space weathering. But exactly what those processes might be has been difficult to pin down with any certainty.

Now, scientists at MIT and the University of Chicago say they have identified the main process that formed the moon's atmosphere and continues to sustain it today. In a study appearing in Science Advances, the team reports that the lunar atmosphere is primarily a product of "impact vaporization."

In their study, the researchers analyzed samples of lunar soil collected by astronauts during NASA's Apollo missions. Their analysis suggests that over the moon's 4.5-billion-year history its surface has been continuously bombarded, first by massive meteorites, then more recently, by smaller, dust-sized "micrometeoroids." These constant impacts have kicked up the lunar soil, vaporizing certain atoms on contact and lofting the particles into the air. Some atoms are ejected into space, while others remain suspended over the moon, forming a tenuous atmosphere that is constantly replenished as meteorites continue to pelt the surface.

The researchers found that impact vaporization is the main process by which the moon has generated and sustained its extremely thin atmosphere over billions of years.

"We give a definitive answer that meteorite impact vaporization is the dominant process that creates the lunar atmosphere," says the study's lead author, Nicole Nie, an assistant professor in MIT's Department of Earth, Atmospheric, and Planetary Sciences. "The moon is close to 4.5 billion years old, and through that time the surface has been continuously bombarded by meteorites. We show that eventually, a thin atmosphere reaches a steady state because it's being continuously replenished by small impacts all over the moon."

Nie's co-authors are Nicolas Dauphas, Zhe Zhang, and Timo Hopp at the University of Chicago, and Menelaos Sarantos at NASA Goddard Space Flight Center.

Weathering's roles

In 2013, NASA sent an orbiter around the moon to do some detailed atmospheric reconnaissance. The Lunar Atmosphere and Dust Environment Explorer (LADEE, pronounced "laddie") was tasked with remotely gathering information about the moon's thin atmosphere, surface conditions, and any environmental influences on the lunar dust.

LADEE's mission was designed to determine the origins of the moon's atmosphere. Scientists hoped that the probe's remote measurements of soil and atmospheric composition might correlate with certain space weathering processes that could then explain how the moon's atmosphere came to be.

Researchers suspect that two space weathering processes play a role in shaping the lunar atmosphere: impact vaporization and "ion sputtering" -- a phenomenon involving solar wind, which carries energetic charged particles from the sun through space. When these particles hit the moon's surface, they can transfer their energy to the atoms in the soil and send those atoms sputtering and flying into the air.

"Based on LADEE's data, it seemed both processes are playing a role," Nie says. "For instance, it showed that during meteorite showers, you see more atoms in the atmosphere, meaning impacts have an effect. But it also showed that when the moon is shielded from the sun, such as during an eclipse, there are also changes in the atmosphere's atoms, meaning the sun also has an impact. So, the results were not clear or quantitative."

Answers in the soil

To more precisely pin down the lunar atmosphere's origins, Nie looked to samples of lunar soil collected by astronauts throughout NASA's Apollo missions. She and her colleagues at the University of Chicago acquired 10 samples of lunar soil, each measuring about 100 milligrams -- a tiny amount that she estimates would fit into a single raindrop.

Nie sought to first isolate two elements from each sample: potassium and rubidium. Both elements are "volatile," meaning that they are easily vaporized by impacts and ion sputtering. Each element exists in the form of several isotopes. An isotope is a variation of the same element, that consists of the same number of protons but a slightly different number of neutrons. For instance, potassium can exist as one of three isotopes, each one having one more neutron, and there being slightly heavier than the last. Similarly, there are two isotopes of rubidium.

The team reasoned that if the moon's atmosphere consists of atoms that have been vaporized and suspended in the air, lighter isotopes of those atoms should be more easily lofted, while heavier isotopes would be more likely to settle back in the soil. Furthermore, scientists predict that impact vaporization, and ion sputtering, should result in very different isotopic proportions in the soil. The specific ratio of light to heavy isotopes that remain in the soil, for both potassium and rubidium, should then reveal the main process contributing to the lunar atmosphere's origins.

With all that in mind, Nie analyzed the Apollo samples by first crushing the soils into a fine powder, then dissolving the powders in acids to purify and isolate solutions containing potassium and rubidium. She then passed these solutions through a mass spectrometer to measure the various isotopes of both potassium and rubidium in each sample.

In the end, the team found that the soils contained mostly heavy isotopes of both potassium and rubidium. The researchers were able to quantify the ratio of heavy to light isotopes of both potassium and rubidium, and by comparing both elements, they found that impact vaporization was most likely the dominant process by which atoms are vaporized and lofted to form the moon's atmosphere.

"With impact vaporization, most of the atoms would stay in the lunar atmosphere, whereas with ion sputtering, a lot of atoms would be ejected into space," Nie says. "From our study, we now can quantify the role of both processes, to say that the relative contribution of impact vaporization versus ion sputtering is about 70:30 or larger." In other words, 70 percent or more of the moon's atmosphere is a product of meteorite impacts, whereas the remaining 30 percent is a consequence of the solar wind.

"The discovery of such a subtle effect is remarkable, thanks to the innovative idea of combining potassium and rubidium isotope measurements along with careful, quantitative modeling," says Justin Hu, a postdoc who studies lunar soils at Cambridge University, who was not involved in the study. "This discovery goes beyond understanding the moon's history, as such processes could occur and might be more significant on other moons and asteroids, which are the focus of many planned return missions."

"Without these Apollo samples, we would not be able to get precise data and measure quantitatively to understand things in more detail," Nie says. "It's important for us to bring samples back from the moon and other planetary bodies, so we can draw clearer pictures of the solar system's formation and evolution."

Read more at Science Daily

Sea level changes shaped early life on Earth, fossil study reveals

A newly developed timeline of early animal fossils reveals a link between sea levels, changes in marine oxygen, and the appearance of the earliest ancestors of present-day animals.

The study reveals clues into the forces that drove the evolution of the earliest organisms, from which all major animal groups descended.

A team from the University of Edinburgh studied a compilation of rocks and fossils from the so-called Ediacaran-Cambrian interval -- a slice of time 580-510 million years ago. This period witnessed an explosion of biodiversity according to fossil records, the causes of which have baffled scientists since Charles Darwin.

The early animals found from this era were all sea-dwellers, at a time when oxygen levels in the air and ocean were much lower than today.

While the very first lifeforms before this time were mostly single-cell, and simple multi-celled organisms, creatures in the Ediacaran Period started to become more complex, with multiple cells organised into body plans that allowed them to feed, reproduce, and move across the ocean floor.

This era also marked the emergence of so-called bilaterian animals -- which display symmetrical body plans, in common with most present-day species including humans.

By compiling data from different sources -- including radioactive dating and geochemical information about the layers of rock in which fossils were found -- the team mapped all major fossil finds and various environmental datasets onto a single timeline.

The new chronology allowed the team to study trends in biodiversity for the period in question with more detail than before.

They combined these insights with further chemical clues from the geological record -- confirming a link between major changes in global sea levels, intervals when shallow marine environments gained more oxygen, and the appearance and diversification of early animal groups.

This dynamic set the stage for several significant bursts in biological diversity, known as the Avalon, White Sea, and Cambrian assemblages, each marking the arrival of new animal groups and the decline of others.

By reconstructing environmental conditions in deepest time, the study unlocks new insights into the ancient forces and pressures that shaped the earliest life on our planet.

The team also identified gaps in the fossil record, suggesting that current knowledge about early animals is biased by the clusters of sites worldwide where fossils have been found and studied.

Dr Fred Bowyer of the University of Edinburgh's School of Geosciences, said: "Constructing a timescale of early animal evolution using the rock record is a daunting task, only made possible through international and interdisciplinary research. But an integrated global approach is crucial. It exposes biases in our records, while also revealing patterns in fossil appearances, sea level cycles, and environmental oxygen."

Read more at Science Daily

Fossil shows how penguins' wings evolved

A tiny fossil penguin plays a huge role in the evolutionary history of the bird, an international study shows.

Published in the Journal of the Royal Society of New Zealand, the study describes a new species of fossil penguin which lived in Otago about 24 million years ago.

Named Pakudyptes hakataramea, the penguin was very small -- about the same size as the little blue penguin, the smallest in the world -- with anatomical adaptations that allowed it to dive.

Lead author Dr Tatsuro Ando, formerly a PhD candidate at the University of Otago -- Ōtākou Whakaihu Waka and now at the Ashoro Museum of Palentology in Japan, collaborated with researchers from Otago, Okayama University of Science and Osaka University.

Dr Ando's inspiration for the paper came from discussions with the late Professor Ewan Fordyce, his supervisor and mentor at Otago.

Researchers analysed three bones -- a humerus, femur and ulna -- found by Professor Fordyce in the Hakataramea Valley, South Canterbury.

Dr Ando says Pakudyptes fills a morphological gap between modern and fossil penguins.

"In particular, the shape of the wing bones differed greatly, and the process by which penguin wings came to have their present form and function remained unclear," he says.

The humerus and ulna highlight how penguins' wings have evolved.

"Surprisingly, while the shoulder joints of the wing of Pakudyptes were very close to the condition of the present-day penguin, the elbow joints were very similar to those of older types of fossil penguins.

"Pakudyptes is the first fossil penguin ever found with this combination, and it is the 'key' fossil to unlocking the evolution of penguin wings."

Co-author Dr Carolina Loch, from Otago's Faculty of Dentistry, says analysis of the internal bone structure conducted at the Faculty of Dentistry, with comparison with data on living penguins provided from the Okayama University of Science, shows these penguins had microanatomical features suggestive of diving.

Modern penguins have excellent swimming abilities, largely due to their dense, thick bones that contribute to buoyancy during diving.

In Pakudyptes, the bone cortex was reasonably thick although the medullary cavity, which contains bone marrow, was open, similar to what we see in the modern little blue penguin, which tends to swim in shallow waters.

The ability for Pakudyptes to dive and swim comes down to the distinctive combination of its bones.

Bones such as the humerus and ulna show areas for attachment of muscles and ligaments which reveal how the wings were being used to swim and manoeuvre under water.

Read more at Science Daily

Key to rapid planet formation

A team of LMU researchers has developed a new model to explain the formation of giant planets such as Jupiter, which furnishes deeper insights into the processes of planet formation and could expand our understanding of planetary systems.

Our solar system is our immediate cosmic neighborhood. We know it well: the Sun at the center; then the rocky planets Mercury, Venus, Earth, and Mars; and then the asteroid belt; followed by the gas giants Jupiter and Saturn; then the ice giants Uranus and Neptune; and finally the Kuiper belt with its comets. But how well do we really know our home? Previous theories have assumed that giant planets are formed by collisions and accumulations of asteroid-like celestial bodies, so-called planetesimals, and the subsequent accretion of gas over the course of millions of years. However, these models explain neither the existence of gas giants located far from their stars nor the formation of Uranus and Neptune.

From grain of dust to giant planet

Astrophysicists from LMU, the ORIGINS cluster, and MPS have developed the first ever model to incorporate all the necessary physical processes that play a role in planet formation. Using this model, they have shown that annular perturbations in protoplanetary disks, so-called substructures, can trigger the rapid formation of multiple gas giants. The results of the study match the latest observations and indicate that the formation of giant planets could happen more efficiently and quickly than previously thought.

With their model, the researchers demonstrate how millimeter-sized dust particles accumulate aerodynamically in the turbulent gas disk, and how this initial perturbation in the disk traps dust and prevents it from disappearing off in the direction of the star. This accumulation makes the growth of planets very efficient, as suddenly a lot of "building material" is available within a compact area and the right conditions for planet formation are present.

"When a planet gets large enough to influence the gas disk, this leads to renewed dust enrichment farther out in the disk," explains Til Birnstiel, Professor of Theoretical Astrophysics at LMU and member of the ORIGINS Cluster of Excellence. "In the process, the planet drives the dust -- like a sheepdog chasing its herd -- into the area outside its own orbit." The process begins anew, from inside to outside, and another giant planet can form. "This is the first time a simulation has traced the process whereby fine dust grows into giant planets," observes Tommy Chi Ho Lau, lead author of the study and doctoral candidate at LMU.

Variety of gas giants in our and other solar systems

In our solar system, the gas giants are situated at a distance of around 5 astronomical units (au) (Jupiter) to 30 au (Neptune) from the Sun. For comparison, the Earth is some 150 million kilometers from the Sun, which is equivalent to 1 au.

The study shows that in other planetary systems, a perturbation could set the process in motion at much larger distances and still happen very rapidly. Such systems have been observed frequently in recent years by the ALMA radio observatory, which has found gas giants in young disks at a distance beyond 200 au. However, the model also explains why our solar system apparently stopped forming additional planets after Neptune: the building material was simply used up.

Read more at Science Daily

Retreat of tropical glaciers foreshadows changing climate's effect on the global ice

As they are in many places around the globe, glaciers perched high in the Andes Mountains are shrinking. Now, researchers at the University of Wisconsin-Madison and their collaborators have uncovered evidence that the high-altitude tropical ice fields are likely smaller than they've been at any time since the last ice age ended 11,700 years ago.

That would make the tropical Andes the first region in the world known to pass that threshold as a result of the steadily warming global climate. It also makes them possible harbingers of what's to come for glaciers globally.

"We think these are the canary in the coal mine. The tropics would probably be the first place you'd expect ice to disappear, and that's what we're seeing," says Shaun Marcott, a professor of geoscience at UW-Madison. Marcott guided the research with colleagues at Boston College and Tulane University. Andrew Gorin, a former Boston College graduate student who is now at University of California, Berkeley, led the study, which appears in the Aug. 2, 2024, issue of the journal Science.

Glaciers grow slowly over time in regions where summer weather isn't warm enough to melt all of the previous winter's snowfall. Over time, unmelted snow collects and gets compacted and begins to move under its own weight, resulting in the year-round ice that defines a glacier.

Satellite imagery and on-the-ground observations have provided conclusive evidence for decades that high-altitude glaciers in the Andes are steadily shrinking as warmer temperatures cause them to melt more quickly than falling snow can replenish them.

What has remained unclear, though, is whether the glaciers' dwindling footprints are anomalously small compared to the rest of the period that began at the end of the last ice age, known as the Holocene. Meanwhile, glaciers in other parts of the world were smaller at some points in the early Holocene, when the global climate was warmer and drier than recent millennia.

"We knew that glaciers ebbed and flowed in the past, so we wanted to learn how the behavior of glaciers today -- melting due to human-caused climate change -- stacks up against their long-term fluctuations," says Andy Jones, a UW-Madison doctoral student and study co-author.

To answer this question, the team of scientists analyzed the geochemistry of bedrock from areas near the edges of four glaciers in the high tropical Andes, choosing sites that satellite imagery showed were exposed by melting ice in only the last two or three decades.

The team specifically looked for evidence of two unique isotopes -- basically chemical flavors -- of a pair of elements with the bedrock's quartz crystals: beryllium-10 and carbon-14. These isotopes are only present in rock that has spent time at or near the Earth's surface as they result from interactions between the rock and cosmic rays, which are high-energy particles that constantly rain down on the planet from outer space.

Bedrock accumulates beryllium-10 and carbon-14 once it's exposed to the surface, so measuring the isotopes' concentrations in rock crystals near glaciers can be useful for understanding the previous extent of ice coverage. The team found "remarkably low" concentrations of both isotopes in nearly all samples, suggesting that melting ice has exposed bedrock near the glaciers for the first time only recently in most of the sampled locations.

Additional analyses -- and the fact that the extremely low concentrations were consistent across sample sites -- made the researchers confident that melting ice, rather than erosion, exposed the bedrock.

"It's highly unlikely this is from erosion," says Marcott. "Because the multiple locations we went to all show the same thing."

This consistency points to a single likely conclusion, according to Marcott: The world's tropical glaciers, more than 99% of which are located in the Andes, are the first to shrink beyond what's been seen in the recent geologic past.

Read more at Science Daily

When it comes to DNA replication, humans and baker's yeast are more alike than different

Humans and baker's yeast have more in common than meets the eye, including an important mechanism that helps ensure DNA is copied correctly, reports a pair of studies published in the journals Science and Proceedings of the National Academy of Sciences.

The findings visualize for the first time a molecular complex -- called CTF18-RFC in humans and Ctf18-RFC in yeast -- that loads a "clamp" onto DNA to keep parts of the replication machinery from falling off the DNA strand.

It is the latest discovery from longtime collaborators Huilin Li, Ph.D., of Van Andel Institute, and Michael O'Donnell, Ph.D., of The Rockefeller University, to shed light on the intricate mechanisms that enable the faithful passage of genetic information from generation to generation of cells.

"The accurate copying of DNA is fundamental to the propagation of life," Li said. "Our findings add key pieces to the puzzle of DNA replication and could improve understanding of DNA replication-related health conditions."

DNA replication is a tightly controlled process that copies the genetic code, allowing its instructions to be conveyed from one generation of cells to the next. In diseases like cancer, these mechanisms can fail, leading to uncontrolled or faulty replication with devastating consequences.

To date, at least 40 diseases, including many cancers and rare disorders, have been linked to problems with DNA replication.

The process begins by unzipping DNA's ladder-like structure, resulting in two strands called the leading and lagging strands. A molecular construction crew then assembles the missing halves of the strands, turning a single DNA helix into two. Much of this work falls to enzymes called polymerases, which assemble the building blocks of DNA.

On their own, however, polymerases aren't good at staying on the DNA strand. They require CTF18-RFC in humans and Ctf18-RFC in yeast to thread a ring-shaped clamp onto the DNA leading strand, and another clamp loader called RFC in both human and yeast to thread the clamp onto the lagging strand. The clamp then closes and signals to the polymerases that they can begin replicating DNA.

Using high-powered cryo-electron microscopes, Li, O'Donnell and their teams revealed previously unknown facets of the leading strand clamp loaders' structures, including a "hook" that forces the leading strand polymerase to let go of the new DNA strand so it can be recognized by the clamp loader. This distinction represents a key difference between the functions of the leading strand clamp loader (CTF18-RFC) and the lagging strand clamp loader (RFC) and illuminates an important aspect of varying DNA duplication mechanisms on the leading and lagging strands.

Lastly, the study identified shared features between the yeast and human leading strand clamp loaders, which demonstrate an evolutionary link between the two. This finding underscores the value of yeast as powerful yet simple models for studying genetics.

Read more at Science Daily

Half a billion-year-old spiny slug reveals the origins of mollusks

A team of researchers including scientists from the University of Oxford have made an astonishing discovery of a new species of mollusc that lived 500 million years ago. The new fossil, called Shishania aculeata*, reveals that the most primitive molluscs were flat, shell-less slugs covered in a protective spiny armour. The findings have been published today in the journal Science.

The new species was found in exceptionally well-preserved fossils from eastern Yunnan Province in southern China dating from a geological Period called the early Cambrian, approximately 514 million years ago. The specimens of Shishania are all only a few centimetres long and are covered in small spikey cones (sclerites) made of chitin, a material also found in the shells of modern crabs, insects, and some mushrooms.

Specimens that were preserved upside down show that the bottom of the animal was naked, with a muscular foot like that of a slug that Shishania would have used to creep around the seafloor over half a billion years ago. Unlike most molluscs, Shishania did not have a shell that covered its body, suggesting that it represents a very early stage in molluscan evolution.

Present-day molluscs have a dizzying array of forms, and include snails and clams and even highly intelligent groups such as squids and octopuses. This diversity of molluscs evolved very rapidly a long time ago, during an event known as the Cambrian Explosion, when all the major groups of animals were rapidly diversifying. This rapid period of evolutionary change means that few fossils have been left behind that chronicle the early evolution of molluscs.

Corresponding author Associate Professor Luke Parry, Department of Earth Sciences, University of Oxford, said: 'Trying to unravel what the common ancestor of animals as different as a squid and oyster looked like is a major challenge for evolutionary biologists and palaeontologists -- one that can't be solved by studying only species alive today. Shishania gives us a unique view into a time in mollusc evolution for which we have very few fossils, informing us that the very earliest mollusc ancestors were armoured spiny slugs, prior to the evolution of the shells that we see in modern snails and clams.'

Because the body of Shishania was very soft and made of tissues that don't typically preserve in the fossil record, the specimens were challenging to study, as many of the specimens were poorly preserved.

First author Guangxu Zhang, a recent PhD graduate from Yunnan University in China who discovered the specimens said: 'At first I thought that the fossils, which were only about the size of my thumb, were not noticeable, but I saw under a magnifying glass that they seemed strange, spiny, and completely different from any other fossils that I had seen. I called it "the plastic bag" initially because it looks like a rotting little plastic bag. When I found more of these fossils and analysed them in the lab I realised that it was a mollusc.'

Associate Professor Parry added: 'We found microscopic details inside the conical spines covering the body of Shishania that show how they were secreted in life. This sort of information is incredibly rare, even in exceptionally preserved fossils.'

The spines of Shishania show an internal system of canals that are less than a hundredth of a millimetre in diameter. These features show that the cones were secreted at their base by microvilli, tiny protrusions of cells that increase surface area, such as in our intestines where they aid food absorption.

This method of secreting hard parts is akin to a natural 3D printer, allowing many invertebrate animals to secrete hard parts with huge variation of shape and function from providing defence to facilitating locomotion.

Hard spines and bristles are known in some present-day molluscs (such as chitons), but they are made of the mineral calcium carbonate rather than organic chitin as in Shishania. Similar organic chitinous bristles are found in more obscure groups of animals such as brachiopods and bryozoans, which together with molluscs and annelids (earthworms and their relatives) form the group Lophotrochozoa.

Professor Parry added: 'Shishania tells us that the spines and spicules we see in chitons and aplacophoran molluscs today actually evolved from organic sclerites like those of annelids. These animals are very different from one another today and so fossils like Shishania tell us what they looked like deep in the past, soon after they had diverged from common ancestors.'

Co-author Jakob Vinther at the University of Bristol said: 'Molluscs today are extraordinarily disparate and they diversified very quickly during the Cambrian Explosion, meaning that we struggle to piece together their early evolutionary history. We know that the common ancestor of all molluscs alive today would have had a single shell, and so Shishania tells us about a very early time in mollusc evolution before the evolution of a shell.'

Co-corresponding author Xiaoya Ma (Yunnan University and University of Exeter) said: 'This new discovery highlights the treasure trove of early animal fossils that are preserved in the Cambrian rocks of Yunnan Province. Soft bodied molluscs have a very limited fossil record, and so these very rare discoveries tell us a great deal about these diverse animals.'

Read more at Science Daily

Dark matter: A camera trap for the invisible

It sounds fantastical, but it's a reality for the scientists who work at the world's largest particle collider:

In an underground tunnel some 350 feet beneath the France-Switzerland border, a huge device called the Large Hadron Collider sends beams of protons smashing into each other at nearly the speed of light, creating tiny eruptions that mimic the conditions that existed immediately after the Big Bang.

Scientists like Duke physicist Ashutosh Kotwal think the subatomic debris of these collisions could contain hints of the universe's "missing matter." And with some help from artificial intelligence, Kotwal hopes to catch these fleeting clues on camera, using a design described May 3 in the journal Scientific Reports.

Ordinary matter -- the stuff of people and planets -- is only part of what's out there. Kotwal and others are hunting for dark matter, an invisible matter that's five times more abundant than the stuff we can see but whose nature remains a mystery.

Scientists know it exists from its gravitational influence on stars and galaxies, but other than that we don't know much about it.

The Large Hadron Collider could change that. There, researchers are looking for dark matter and other mysteries using detectors that act like giant 3D digital cameras, taking continuous snapshots of the spray of particles produced by each proton-proton collision.

Only ordinary particles trigger a detector's sensors. If researchers can make dark matter at the LHC, scientists think one way it could be noticeable is as a sort of disappearing act: heavy charged particles that travel a certain distance -- 10 inches or so -- from the point of collision and then decay invisibly into dark matter particles without leaving a trace.

If you retraced the paths of these particles, they would leave a telltale "disappearing track" that vanishes partway through the detector's inner layers.

But to spot these elusive tracks they'll need to act fast, Kotwal says.

That's because the LHC's detectors take some 40 million snapshots of flying particles every second.

That's too much raw data to hang on to everything and most of it isn't very interesting. Kotwal is looking for a needle in a haystack.

"Most of these images don't have the special signatures we're looking for," Kotwal said. "Maybe one in a million is one that we want to save."

Researchers have just a few millionths of a second to determine if a particular collision is of interest and store it for later analysis.

"To do that in real time, and for months on end, would require an image recognition technique that can run at least 100 times faster than anything particle physicists have ever been able to do," Kotwal said.

Kotwal thinks he may have a solution. He has been developing something called a "track trigger," a fast algorithm that is able to spot and flag these fleeting tracks before the next collision occurs, and from among a cloud of tens of thousands of other data points measured at the same time.

His design works by divvying up the task of analyzing each image among a large number of AI engines running simultaneously, built directly onto a silicon chip. The method processes an image in less than 250 nanoseconds, automatically weeding out the uninteresting ones.

Kotwal first described the approach in a sequence of two papers published in 2020 and 2021. In the more recent paper published this May in Scientific Reports, he and a team of undergraduate student co-authors show that his algorithm can run on a silicon chip.

Kotwal and his students plan to build a prototype of their device by next summer, though it will be another three or four years before the full device -- which will consist of about 2000 chips -- can be installed at detectors at the LHC.

As the performance of the accelerator continues to crank up, it will produce even more particles. And Kotwal's device could help make sure that, if dark matter is hiding among them, scientists won't miss it.

Read more at Science Daily

Underwater mapping reveals new insights into melting of Antarctica's ice shelves

Clues to future sea level rise have been revealed by the first detailed maps of the underside of a floating ice shelf in Antarctica.

An international research team -- including scientists from the University of East Anglia (UEA) -- deployed an unmanned submersible beneath the Dotson Ice Shelf in West Antarctica.

The underwater vehicle, 'Ran', was programmed to dive into the cavity of the 350metre-thick ice shelf and scan the ice above it with an advanced sonar. Over 27 days, the submarine travelled more than 1000 kilometres back and forth under the shelf, reaching 17 kilometres into the cavity.

An ice shelf is a mass of glacial ice, fed from land by tributary glaciers, that floats in the sea above an ice shelf cavity. Dotson Ice Shelf is part of the West Antarctic ice sheet -- and next to Thwaites Glacier -- which is considered to have a potentially large impact on future sea level rise due to its size and location.

The researchers report their findings of this unique survey in a new paper published today in the journal Science Advances.

They found some things as expected, for example the glacier melts faster where strong underwater currents erode its base. Using the submersible, they were able to measure the currents below the glacier for the first time and prove why the western part of Dotson Ice Shelf melts so fast. They also found evidence of very high melt at vertical fractures that extend through the glacier.

However, the team also saw new patterns on the glacier base that raise questions. The mapping showed that the base is not smooth, but there is a peak and valley ice-scape with plateaus and formations resembling sand dunes. The researchers hypothesize that these may have been formed by flowing water under the influence of Earth's rotation.

Lead author Anna Wåhlin, Professor of Oceanography at the University of Gothenburg in Sweden, said: "We have previously used satellite data and ice cores to observe how ice shelves change over time. By navigating the submersible into the cavity, we were able to get high resolution maps of the ice underside. It's a bit like seeing the back of the moon for the first time."

The expedition was carried out in regions of drifting ice in West Antarctica in 2022 during a research cruise for the TARSAN project, a joint US-UK funded initiative that is part of the International Thwaites Glacier Collaboration. The project is studying how atmospheric and oceanic processes are influencing the behaviour of the Thwaites and Dotson Ice Shelves -- neighbouring ice shelves which are behaving differently.

Co-author Dr Rob Hall, from UEA's School of Environmental Sciences, co-led the cruise on the RV Nathaniel B Palmer, on which the observations were made in January to March 2022. He said: "Anna and her team successfully piloted their autonomous underwater vehicle 'Ran' over 1000 km under Dotson Ice Shelf collecting a huge range of data and samples, which will take several years to process and analyse.

"The incredible high-resolution images of the underside of the ice shelf are the icing on the cake and will open up a whole new avenue of scientific research."

Prof Karen Heywood, also from UEA and a co-author, is UK lead scientist on the TARSAN project. She said: "This has been such an exciting project to work on. When Anna sent round the first images of the underside of the Dotson ice shelf we were thrilled -- nobody had ever seen this before. But we were also baffled -- there were cracks and swirls in the ice that we weren't expecting. It looked more like art!

"We wondered what could be causing these. All of the glaciologists and the oceanographers in the TARSAN project got together to brainstorm ideas. It's been like detective work -- using fundamental ocean physics to test theories against the shape and size of the patterns under the ice. We've been able to show for the first time some of the processes that melt the underside of ice shelves.

Prof Heywood added: "These ice shelves are already floating on the sea, so their melting doesn't directly affect sea level. However ultimately the melting of ice shelves causes the glaciers on land further upstream to flow faster and destabilise, which does lead to sea level rise, so these new observations will help the community of ice modellers to reduce the large uncertainties in future sea level."

Scientists now realise there is a wealth of processes left to discover in future research missions under the glaciers.

"The mapping has given us new data that we need to look at more closely. It is clear that many previous assumptions about melting of glacier undersides are falling short. Current models cannot explain the complex patterns we see. But with this method, we have a better chance of finding the answers," said Prof Wåhlin.

"Better models are needed to predict how fast the ice shelves will melt in the future. It is exciting when oceanographers and glaciologists work together, combining remote sensing with oceanographic field data. This is needed to understand the glaciological changes taking place -- the driving force is in the ocean."

In January 2024, the group returned with Ran to Dotson Ice Shelf to repeat the surveys, hoping to document changes. However, they were only able to complete one dive before Ran disappeared under the ice.

Read more at Science Daily

Precise genetics: New CRISPR method enables efficient DNA modification

The research group led by Prof. Markus Affolter at the Biozentrum, University of Basel, has developed a new method that further improves the existing CRISPR/Cas technologies: it allows a more precise and seamless introduction of tags into proteins at the gene level. This technology could significantly improve research on proteins in living organisms and opens up new possibilities for medical research.

With the revolutionary CRISPR/Cas technology, the DNA of living organisms can be precisely altered.

Using a guide RNA that recognizes a specific DNA sequence, Cas9 protein is recruited to that sequence and cuts the DNA.

This targeted cut allows the DNA to be repaired or altered at this specific location.

Prof. Markus Affolter's team at the Biozentrum, University of Basel, has now developed a new method called SEED/Harvest in the fruit fly (Drosophila melanogaster). This method combines the CRISPR-Cas9 technique with the Single-Strand Annealing (SSA) repair pathway, enabling genome-wide changes to be carried out more efficiently and without leaving unwanted scars.

The study has been published in Developmental Cell.

Two methods combined

The SEED/Harvest method proceeds in two steps. In a first step, the researchers introduced a marker gene into the desired DNA site within a protein-coding region.

This marker is placed at the targeted location and is used to isolate successful modifications.

In a second step, the marker is excised and the DNA breakpoints are repaired by the Single-Strand Annealing (SSA) repair pathway.

"This enables us to cut the DNA seamless while maintaining its full function," explains first author Gustavo Aguilar.

"The combination of both methods makes it possible to mark any desired protein in the genome without collateral damage, allowing us to study the functions of proteins in living organisms."

More precise and efficient

"Since we would like to introduce and analyze changes in the DNA throughout the genome for our research, the method must be both precise and efficient," explains Affolter.

"And the SEED/Harvest method is both. It combines the most robust screening of successful insertions and all the advantages of seamless tagging."

New research opportunities

One of the advantages of the SEED/Harvest method is that proteins can be labeled in specific tissues and cell types.

"We can now control and determine in various tissues and developmental stages when and where genes are activated or inactivated" adds Gustavo Aguilar.

This opens up new possibilities for research to investigate the dynamics of proteins systematically in living cells in real-time.

Read more at Science Daily

Generation X and millennials in US have higher risk of developing 17 cancers compared to older generations

A new large study led by researchers at the American Cancer Society (ACS) suggests incidence rates continued to rise in successively younger generations in 17 of the 34 cancer types, including breast, pancreatic, and gastric cancers. Mortality trends also increased in conjunction with the incidence of liver (female only), uterine corpus, gallbladder, testicular, and colorectal cancers. The report will be published today in the journal The Lancet Public Health.

"These findings add to growing evidence of increased cancer risk in post-Baby Boomer generations, expanding on previous findings of early-onset colorectal cancer and a few obesity-associated cancers to encompass a broader range of cancer types," said Dr. Hyuna Sung, lead author of the study and a senior principal scientist of surveillance and health equity science at the American Cancer Society. "Birth cohorts, groups of people classified by their birth year, share unique social, economic, political, and climate environments, which affect their exposure to cancer risk factors during their crucial developmental years. Although we have identified cancer trends associated with birth years, we don't yet have a clear explanation for why these rates are rising."

In this analysis, researchers obtained incidence data from 23,654,000 patients diagnosed with 34 types of cancer and mortality data from 7,348,137 deaths for 25 types of cancer for individuals aged 25-84 years for the period Jan 1, 2000, to Dec 31, 2019, from the North American Association of Central Cancer Registries and the U.S. National Center for Health Statistics, respectively. To compare cancer rates across generations, they calculated birth cohort-specific incidence rate ratios and mortality rate ratios, adjusted for age effect and period effect, by birth years, separated by five-year intervals, from 1920 to 1990.

Researchers found that incidence rates increased with each successive birth cohort born since approximately 1920 for eight of 34 cancers. In particular, the incidence rate was approximately two-to-three times higher in the 1990 birth cohort than in the 1955 birth cohort for pancreatic, Kidney, and small intestinal cancers in both male and female individuals; and for liver cancer in female individuals. Additionally, incidence rates increased in younger cohorts, after a decline in older birth cohorts, for nine of the remaining cancers including breast cancer (estrogen-receptor positive only), uterine corpus cancer, colorectal cancer, non-cardia gastric cancer, gallbladder cancer, ovarian cancer, testicular cancer, anal cancer in male individuals, and Kaposi sarcoma in male individuals. Across cancer types, the incidence rate in the 1990 birth cohort ranged from 12% for ovarian cancer to 169% for uterine corpus cancer higher than the rate in the birth cohort with the lowest incidence rate. Notably, mortality rates increased in successively younger birth cohorts alongside incidence rates for liver cancer (female only), uterine corpus, gallbladder, testicular, and colorectal cancers.

"The increase in cancer rates among this younger group of people indicate generational shifts in cancer risk and often serve as an early indicator of future cancer burden in the country. Without effective population-level interventions, and as the elevated risk in younger generations is carried over as individuals age, an overall increase in cancer burden could occur in the future, halting or reversing decades of progress against the disease," added Dr. Ahmedin Jemal, senior vice president, surveillance and health equity science at the American Cancer Society and senior author of the study. "The data highlights the critical need to identify and address underlying risk factors in Gen X and Millennial populations to inform prevention strategies."

Read more at Science Daily

The rotation of a nearby star stuns astronomers

Astronomers from the University of Helsinki have found that the rotational profile of a nearby star, V889 Herculis, differs considerably from that of the Sun. The observation provides insights into the fundamental stellar strophysics and helps understanding the activity of the Sun, its spot structures and eruptions.

The Sun rotates the fastest at the equator, whereas the rotation rate slows down at higher latitudes and is the slowest as the polar regions. But a nearby Sun-like star V889 Herculis, some 115 light years away in the constellation of Hercules, rotates the fastest at a latitude of about 40 degrees, while both the equator and polar regions rotate more slowly.

Similar rotational profile has not been observed for any other star. The result is stunning because stellar rotation has been considered a well-understood fundamental physical parameter but such a rotational profile has not been predicted even in computer simulations.

"We applied a newly developed statistical technique to the data of a familiar star that has been studied in the University of Helsinki for years. We did not expect to see such anomalies in stellar rotation. The anomalies in the rotational profile of V889 Herculis indicate that our understanding of stellar dynamics and magnetic dynamos are insufficient, "explains researcher Mikko Tuomi who coordinated the research

Dynamics of a ball of plasma

The target star V889 Herculis is much like a young Sun, telling a story about the history and evolution of the Sun. Tuomi emphasises that it is crucial to understand stellar astrophysics in order to, for instance, predict activity-induced phenomena on the Solar surface, such as spots and eruptions.

Stars are spherical structures where matter is in the state of plasma, consisting of charged particles. They are dynamical objects that hang in a balance between the pressure generated in nuclear reactions in their cores and their own gravity. They have no solid surfaces unlike many planets.

The stellar rotation is not constant for all latitudes -- an effect known as differential rotation. It is caused by the fact that hot plasma rises to the star's surface via a phenomenon called convection, which in turn has an effect on the local rotation rate. This is because angular momentum must be conserved and the convection occurs perpendicular to the rotational axis near equator whereas it is parallel to the axis near the poles.

However, many factors such as stellar mass, age, chemical composition, rotation period, and magnetic field have effects on the rotation and give rise to variations in the differential rotation profiles.

A statistical method for determining rotational profile

Thomas Hackman, docent of astronomy, who participated in the research, explains that the Sun has been the only star for which studying the rotational profile has been possible.

"Stellar differential rotation is a very crucial factor that has an effect on the magnetic activity of stars. The method we have developed opens a new window into the inner workings of other stars.

"The astronomers at the Department of Particle Physics and Astrophysics of the Helsinki University have determined the rotational profile of two nearby young stars by applying a new statistical modelling to long-baseline brightness observations. They modelled the periodic variations in the observations by accounting for the differences in the apparent spot movement at different latitudes. The spot movement then enabled estimating the rotational profile of the stars.

"The second one of the targets stars, LQ Hydrae in the constellation of Hydra, was found to be rotating much like a rigid body -- the rotation appeared unchanged from the equator to the poles, which indicates that the differences are very small."

Observations from the Fairborne Observatory

The researchers base their results on the observations of the target stars from the Fairborn observatory. The brightnesses of the stars have been monitored with robotic telescopes for around 30 years, which provides insights into the behaviour of the stars over a long period of time.

Tuomi appreciates the work of senior astronomer Gregory Henry, of Tennessee University, United States, who leads the Fairborne observational campaign.

"For many years, Greg's project has been extremely valuable in understanding the behaviour of nearby stars. Whether the motivation is to study the rotation and properties of young, active stars or to understand the nature of stars with planets, the observations from Fairborn Observatory have been absolutely crucial. It is amazing that even in the era of great space-based observatories we can obtain fundamental information on the stellar astrophysics with small 40cm ground-based telescopes.

Read more at Science Daily

Scientists discover entirely new wood type that could be highly efficient at carbon storage

Researchers undertaking an evolutionary survey of the microscopic structure of wood from some of the world's most iconic trees and shrubs have discovered an entirely new type of wood. 

This discovery may open new opportunities to improve carbon sequestration in plantation forests by planting a fast-growing tree more commonly seen in ornamental gardens.

The study found that Tulip Trees, which are related to magnolias and can grow well over 100 feet tall, have a unique type of wood that does not fit into either category of hardwood or softwood.

Scientists from Jagiellonian University and the University of Cambridge used a low temperature scanning electron microscope (cryo-SEM) to image the nanoscale architecture of secondary cell walls (wood) in their native hydrated state.

The researchers found the two surviving species of the ancient Liriodendron genus, commonly known as the Tulip Tree (Liriodendron tulipifera) and Chinese Tulip Tree (Liriodendron chinense) have much larger macrofibrils then their hardwood relatives (macrofibrils are long fibres aligned in layers in the secondary cell wall).

Lead author of the research published in New Phytologist, Dr Jan Łyczakowski from Jagiellonian University, said: "We show Liriodendrons have an intermediate macrofibril structure that is significantly different from the structure of either softwood or hardwood. Liriodendrons diverged from Magnolia Trees around 30-50 million years ago, which coincided with a rapid reduction in atmospheric CO2. This might help explain why Tulip Trees are highly effective at carbon storage."

The team suspect it is the larger macrofibrils in this "midwood" or "accumulator-wood" that is behind the Tulip Trees' rapid growth.

Łyczakowski added: "Both Tulip Tree species are known to be exceptionally efficient at locking in carbon, and their enlarged macrofibril structure could be an adaptation to help them more readily capture and store larger quantities of carbon when the availability of atmospheric carbon was being reduced. Tulip Trees may end up being useful for carbon capture plantations. Some east Asian countries are already using Liriodendron plantations to efficiently lock in carbon, and we now think this might be related to its novel wood structure." 

Liriodendron tulipifera are native to northern America and Liriodendron chinense is a native species of central and southern China and Vietnam.

The discovery was part of a survey of 33 tree species from the Cambridge University Botanic Garden's Living Collections exploring how wood ultrastructure evolved across softwoods (gymnosperms such as pines and conifers) and hardwoods (angiosperms including oak, ash, birch, and eucalypts).

Łyczakowski said: "Despite its importance, we know little about how the structure of wood evolves and adapts to the external environment. We made some key new discoveries in this survey -- an entirely novel form of wood ultrastructure never observed before and a family of gymnosperms with angiosperm-like hardwood instead of the typical gymnosperm softwood. 

"The main building blocks of wood are the secondary cell walls, and it is the architecture of these cell walls that give wood its density and strength that we rely on for construction. Secondary cell walls are also the largest repository of carbon in the biosphere, which makes it even more important to understand their diversity to further our carbon capture programmes to help mitigate climate change."

Wood ultrastructure

Wood ultrastructure refers to the detailed microscopic architecture of wood, encompassing the arrangement and organisation of its material components. This survey of wood using a cryo-scanning electron microscope focused on:

•  The Secondary Cell Wall: This is composed of mainly cellulose plus other complex sugars and is impregnated with lignin to make the whole structure rigid. These components make up the macrofibril, forming long aligned fibres that are arranged in distinct layers within the secondary cell wall.
• The Macrofibril: This is currently the smallest structure we can measure using the cryoSEM and is in the order of 10 -- 40 nanometres thick. It is composed of cellulose microfibrils (3-4 nanometres) plus other components.

Studying the wood ultrastructure is crucial for various applications, including wood processing, material science, and understanding the ecological and evolutionary aspects of trees. Understanding the biology behind tree growth and wood deposition is also valuable information when calculating carbon capture.

The Living Collections of the Cambridge University Botanic Garden

The wood samples were collected from trees in the Cambridge University Botanic Garden in coordination with the Garden's Collections Coordinator Margeaux Apple. Fresh samples of wood deposited in the previous spring growing season were collected from a selection of trees to reflect the evolutionary history of gymnosperm and angiosperm populations as they diverged and evolved. 

Microscopy Core Facility Manager at the Sainsbury Laboratory Cambridge University, Dr Raymond Wightman, said: "We analysed some of the world's most iconic trees like the giant sequoia, Wollemi pine and so-called "living fossils" such as Amborella trichopoda, which is the sole surviving species of a family of plants that was the earliest still existing group to evolve separately from all other flowering plants.

"Our survey data has given us new insights into the evolutionary relationships between wood nanostructure and the cell wall composition, which differs across the lineages of angiosperm and gymnosperm plants. Angiosperm cell walls possess characteristic narrower elementary units, called macrofibrils, compared to gymnosperms and this small macrofibril emerged after divergence from the Amborella trichopodaancestor." 

Lyczakowski and Wightman also analysed the cell wall macrofibrils of two gymnosperm plants in the Gnetophytes family -- Gnetum gnemon and Gnetum edule -- and confirmed both have a secondary cell wall ultrastructure synonymous with the hardwood cell wall structures of angiosperms.

This is an example of convergent evolution where the Gnetophytes have independently evolved a hardwood-type structure normally only seen in angiosperms.

The survey was undertaken while the UK was sweltering under the UK's 4th hottest ever recorded summer in 2022. 

"We think this could be the largest survey, using a cryo-electron microscope, of woody plants ever done," Wightman said. "It was only possible to do such a large survey of fresh hydrated wood because the Sainsbury Lab is located within the grounds of the Cambridge University Botanic Garden. We collected all the samples during the summer of 2022 -- collecting in the early morning, freezing the samples in ultra-cold slush nitrogen and then imaging the samples through to midnight.

Read more at Science Daily

Recent volcanic 'fires' in Iceland triggered by storage and melting in crust

Scientists from UC San Diego's Scripps Institution of Oceanography have detected geochemical signatures of magma pooling and melting beneath the subsurface during the "Fagradalsfjall Fires," that began on Iceland's Reykjanes peninsula in 2021.

Continuous sampling of the erupted lavas from the Fagradalsfjall volcano enabled a detailed time-series analysis of geochemical signals. These show that the start of the eruption began with massive pooling of magma, contrasting initial hypothesis for magma ascent straight from the mantle.

Scripps Oceanography geologist James Day and his colleagues report on the analyses July 31 in the journal Nature.

"By collecting lavas in regular intervals, and then measuring their compositions in the laboratory, we can tell what's feeding the volcano at depth," said study lead Day. "It's a bit like taking regular measurements of someone's blood. In this case, the volcano's 'blood' are the molten lavas that emanate so spectacularly from it."

Day, students at Scripps Oceanography, and international colleagues have been studying basaltic lavas from other recent volcanic eruptions in addition to Iceland. These include the 2021 eruption of the Tajogaite volcano on the island of La Palma in the Canary Islands and the 2022 eruption of Mauna Loa in Hawai'i. They have found evidence for similar magma pooling beneath La Palma.

"What makes the Iceland eruption so remarkable is the huge signal of crust within the earliest lavas," said Day. "Along with our studies from La Palma, it suggests crustal magma storage may be a common process involved in the run up to larger basaltic eruptions like those in Iceland or the Canary Islands. This information will be important for understanding volcanic hazard in the future," he added, "as it may help to forecast volcanic activity."

Previous studies had suggested that the Fagradalsfjall Fires erupted from the surface without interaction with the crust. Day's team, including UC San Diego undergraduate student Savannah Kelly, used the isotopic composition of the element osmium to understand what was happening beneath the volcano.

"What's useful about using osmium," said Day, "is that one of its isotopes is produced by the radiogenic decay of another metal, rhenium. Because the elements behave differently during melting, one of the elements, rhenium, is enriched in Earth's crust." Day and colleagues took advantage of the distinct behaviors of rhenium and osmium to show that the early lavas from the Fagradalsfjall Fires were contaminated by crust.

Earth can be broken up into a series of layers. The deepest portion is the metallic core. The shallowest layers are the atmosphere, ocean, and the rocky crust. All human beings live on the crust, which is dominated by rock types such as granite or basalt like that found in Iceland's lavas. In between the core and crust is the vast mantle of the Earth. This mantle layer is where melting occurs to produce the magmas feeding volcanoes like those in Iceland.

Previous works published on the recent volcanic eruptions on the Reykjanes Ridge had used other geochemical fingerprints to study the lavas. These fingerprints suggested only mantle contributions to the lavas. Osmium isotopes are highly sensitive to crust and enabled the unambiguous identification of its addition into the early lavas.

"The work began as undergraduate research experience for Savannah (Kelly) and we fully expected to see mantle signatures in the lavas throughout the eruption," said Day. "You can imagine our astonishment when we were sitting in front of the mass spectrometer measuring the early samples and saw obvious signals of crust within them."

The team analyzed lavas erupting from the Fagradalsfjall volcano in 2021 and in 2022. The 2021 lavas were contaminated by crust, the 2022 lavas were not. They conclude that the earliest lavas pooled in the crust and interaction with the crust may have helped trigger the eruption.

"After that, it appears that the magma of later eruptions used pre-existing pathways to get to the surface," Day said.

Day and colleagues plan to continue their work on Iceland and other basaltic eruptions into the future. Previous eruptions on the Reykjanes peninsula have lasted for centuries.

"It seems that the volcanic 'fires' in Iceland will outlast me," Day said. "The eruptions that are likely to continue there will provide a treasure trove of important scientific information on how volcanoes work and their associated hazards. Our study shows that the beginning of the eruption was not just visually spectacular, but was also geochemically so."

Read more at Science Daily

What shapes a virus's pandemic potential? SARS-CoV-2 relatives yield clues

Two of the closest known relatives to SARS-CoV-2 -- a pair of bat coronaviruses discovered by researchers in Laos -- may transmit poorly in people despite being genetically similar to the COVID-19-causing virus, a new Yale study reveals.

The findings -- published July 29 in the journal Nature Microbiology -- provide clues as to why some viruses have greater "pandemic potential" than others and how researchers might go about identifying those that do before they become widespread.

For a virus to cause a pandemic it needs to be able to transmit between people, enter human cells, evade the body's defense systems, and cause disease. SARS-CoV-2, the virus that precipitated the COVID-19 pandemic, has been able to do all of this. But it's not yet clear why it is so efficient.

"We don't know what makes a virus have pandemic potential," said Mario Peña-Hernández, a Yale Ph.D. student in the labs of Akiko Iwasaki and Craig Wilen and lead author of the study. "These bat strains are 97% identical to SARS-CoV-2 genetically and we thought that, because they are the virus's closest known relatives, their phenotypic behavior -- or the way they infect and cause disease -- would be similar to SARS-CoV-2. But we found that wasn't true."

While the bat coronaviruses were able to efficiently enter some human cells and evade defense systems (often better than SARS-CoV-2 does), they did not transmit, or spread, well between hamsters and caused more mild disease in mice.

"The findings show us that we cannot tell from genomes alone what virus strains have the capacity to create a pandemic," said Peña-Hernández.

Other authors included Iwasaki, Sterling Professor of Immunobiology at Yale School of Medicine (YSM) and professor of epidemiology (microbial diseases) at Yale School of Public Health, and Wilen, an associate professor of laboratory medicine and of immunobiology at YSM.

For the study, the researchers used copies of the two bat coronaviruses and tested how well they were able to infect lab-cultured human respiratory tract cells and rodents. The work was done under the university's highest standard of biosafety. (Specifically, it was conducted under what is characterized as biosafety level 3+, requirements for which include restricted lab access, specialized personal protective equipment and respirators, and for experiments to be performed in biocontainment cabinets in a negative pressure facility).

The researchers found that while the two bat coronaviruses were effective at infecting cells isolated from the human bronchus -- the airway that connects the trachea to the lung -- they did not replicate well in cells from the nose.

"This is important to know, as most virus transmissions likely happen in the nose," said Iwasaki, a senior author of the study. "That these viruses don't replicate in the nose as well as SARS-CoV-2 could be an important indicator of why they failed to transmit in the animal models." The body has two types of immune protection: innate immunity -- a broad, general, first line of defense -- and adaptive immunity, which develops over time and can protect against more specific pathogens that individuals have already been exposed to. Innate immunity is particularly important against novel viruses to which people may have no adaptive immunity. In the study, the researchers found that the two bat coronaviruses were able to evade certain innate immunity molecules that fight infections.

"So the viruses can infect airway cells and dodge the body's defenses, yet they still failed to transmit between animals," said Wilen, a senior author of the study. "SARS-CoV-2 could evade innate immunity and transmit, so this suggested to us that these bat coronaviruses lack something that SARS-CoV-2 has."

One thing missing from these viruses is a molecular bit known as a "furin cleavage site." In SARS-CoV-2 and some other viruses, the spike protein of the virus can be cut by an enzyme called furin in order for the virus to efficiently enter human cells. Previous studies have found that mutated versions of SARS-CoV-2 lacking this site are less easily transmitted and cause less severe disease. In the new study, the researchers also found SARS-CoV-2 without this cleavage site didn't replicate as well in nasal cells, much like the two bat coronaviruses. In hamsters, viruses that lacked furin cleavage sites were quickly outcompeted by those that had them.

Whether a virus has this cleavage site could be one feature to look out for in the search to identify viral threats, said the researchers. However, it is likely that other viral features from this family of viruses also confer transmission or disease-causing potential. This, they said, highlights the importance of studying these viruses in the laboratory to identify these features. For example, how well a virus replicates in nasal cells could also serve as a proxy for assessing its transmission capacity.

Overall, the findings indicate that these two bat coronaviruses pose a more modest threat to humans, although it is possible that small genetic changes in these or similar viruses may evolve and significantly enhance pandemic risk. However, even in the event that the viruses did cross over to humans, the researchers found that adaptive immunity against SARS-CoV-2 was protective; blood sera samples taken from individuals who were vaccinated against or previously infected by SARS-CoV-2 neutralized the viruses.

"But understanding whether viruses have the potential to transmit between humans is important," said Iwasaki, who is also a professor of dermatology at YSM, a professor of molecular, cellular, and developmental biology in Yale's Faculty of Arts and Sciences, and an investigator of the Howard Hughes Medical Institute.

Read more at Science Daily

NASA data shows July 22, 2024 was Earth's hottest day on record

July 22, 2024, was the hottest day on record, according to a NASA analysis of global daily temperature data. July 21 and 23 of this year also exceeded the previous daily record, set in July 2023. These record-breaking temperatures are part of a long-term warming trend driven by human activities, primarily the emission of greenhouse gases. As part of its mission to expand our understanding of Earth, NASA collects critical long-term observations of our changing planet.

"In a year that has been the hottest on record to date, these past two weeks have been particularly brutal," said NASA Administrator Bill Nelson.

"Through our over two dozen Earth-observing satellites and over 60 years of data, NASA is providing critical analyses of how our planet is changing and how local communities can prepare, adapt, and stay safe. We are proud to be part of the Biden-Harris Administration efforts to protect communities from extreme heat."

This preliminary finding comes from data analyses from Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) and Goddard Earth Observing System Forward Processing (GEOS-FP) systems, which combine millions of global observations from instruments on land, sea, air, and satellites using atmospheric models.

GEOS-FP provides rapid, near-real time weather data, while the MERRA-2 climate reanalysis takes longer but ensures the use of best quality observations.

These models are run by the Global Modeling and Assimilation Office (GMAO) at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Daily global average temperature values from MERRA-2 for the years 1980-2022 are shown in white, values for the year 2023 are shown in pink, and values from 2024 through June are shown in red.

Daily global temperature values from July 1 to 23, 2024, from GEOS-FP are shown in purple.

The results agree with an independent analysis from the European Union's Copernicus Earth Observation Programme.

While the analyses have small differences, they show broad agreement in the change in temperature over time and hottest days.

Read more at Science Daily

Local food production saves costs and carbon

Emphasizing local food production over imported substitutes can lead to significant cost and carbon savings, according to data from the Inuvialuit Settlement Region in the Canadian Arctic. The research, conducted by the Max Planck Institute for Evolutionary Anthropology and the Inuvialuit Regional Corporation, shows potential annual savings of more than 3.1 million Canadian dollars and roughly half the carbon emissions when locally harvested food is used instead of imported food. The study underscores the importance of climate change policies that take local food systems into account. Weakening of these local systems could lead to increased emissions and jeopardize the health and food security of remote communities.

Local foods are critical to the food security and health of Indigenous peoples around the world, but local "informal" economies are often invisible in official economic statistics. Consequently, these economies may be overlooked in the policies designed to combat climate change. For instance, Indigenous communities in the North American Arctic are characterized by mixed economies featuring hunting, fishing, gathering and trapping activities, alongside the formal wage economy. The region is also undergoing a rapid transformation due to social, economic and climatic changes. In Canada, the introduction of carbon taxation has implications for the cost of fuel utilized in local food harvesting.

As a first step in understanding the sensitivity of Arctic food systems to carbon tax policy, researchers from the Max Planck Institute for Evolutionary Anthropology, in collaboration with the Innovation, Inuvialuit Science, and Climate Change Division of the Inuvialuit Regional Corporation, attempted to estimate the economic and environmental importance of local food production in the Inuvialuit Settlement Region in the western Canadian Arctic. To do this, the authors utilized data from a regional study of harvesting conducted in 2018, aiming to calculate the total edible weight of food produced by Inuit harvesters within a one-year timeframe.

Reducing CO2 emissions requires locally-adapted policy

The authors then calculated what it would cost to replace these foods with market substitutes, like beef, pork, chicken or farmed fish. They then gathered data from agriculture and transport science to estimate the carbon emissions associated with producing and shipping market substitutes to Arctic communities. Finally, using data from a community-based study of Inuit harvesting in one community in the Inuvialuit Settlement Region (Ulukhaktok), the research team was able to estimate the amount of gasoline used per kilogram of food harvested, and used this information to infer the total amount of gasoline used in local food production in the region.

The resulting estimates suggest that, under plausible scenarios, replacing locally-harvested foods in the Inuvialuit Settlement Region with imported market substitutes would cost over 3.1 million Canadian dollars per year and emit over 1,000 tonnes of CO2-equivalent emissions per year. In contrast, gasoline inputs to local harvesting cost approximately 295,000 Canadian dollars and result in 317 to 496 tonnes of emissions, less than half of what would be emitted by market substitutes. "Our findings illustrate how local food harvesting, even when reliant on fossil fuels -- as is the case in Canadian Arctic communities -- are more economically-efficient and less carbon intensive than industrial food production," says first author Elspeth Ready, a researcher at the Max Planck Institute for Evolutionary Anthropology. "Local food harvesting also reduces reliance on supply chains that are vulnerable to climate change."

Read more at Science Daily

Scientists untangle interactions between the Earth's early life forms and the environment over 500 million years

The atmosphere, the ocean and life on Earth interacted over the past 500-plus million years in ways that improved conditions for early organisms to thrive. Now, an interdisciplinary team of scientists has produced a perspective article of this co-evolutionary history published in multidisciplinary open-access journal National Science Review.

"One of our tasks was to summarize the most important discoveries about carbon dioxide and oxygen in the atmosphere and ocean over the past 500 million years," says Syracuse University geochemistry professor Zunli Lu, lead author on the paper. "We reviewed how those physical changes affected the evolution of life in the ocean. But it's a two-way street. The evolution of life also impacted the chemical environment. It is not a trivial task to understand how to build a habitable Earth over long time scales"

The team from Syracuse University, Oxford University and Stanford University explored the intricate feedbacks among ancient life forms, including plants and animals, and the chemical environment in the current Phanerozoic Eon, which began approximately 540 million years ago.

At the start of the Phanerozoic, carbon dioxide levels in the atmosphere were high, and oxygen levels were low. Such a condition would be difficult for many modern organisms to thrive. But ocean algae changed that. They absorbed carbon dioxide from the atmosphere, locked it into organic matter and produced oxygen through photosynthesis.

The ability of animals to live in an ocean environment was affected by oxygen levels. Lu is studying where and when ocean oxygen levels may have risen or fallen during the Phanerozoic using geochemical proxies and model simulations. Co-author Jonathan Payne, professor of Earth and planetary sciences at Stanford University, compares an ancient animal's estimated metabolic requirements to places where it survived or disappeared in the fossil record.

As photosynthetic algae removed atmospheric carbon into sedimentary rocks to lower carbon dioxide and raise oxygen levels, the algae's enzymes became less efficient in fixing carbon. Therefore, algae had to figure out more complicated ways of doing photosynthesis at lower carbon dioxide and higher oxygen levels. It accomplished this by creating internal compartments for photosynthesis with control over the chemistry.

"For algae, it is changes in the environmental ratio of O2/CO2 that seems to be key to driving improved photosynthetic efficiency," says co-author Rosalind Rickaby, who is a professor of geology at Oxford. "What is really intriguing is that these improvements in photosynthetic efficiency may have expanded the chemical envelope of habitability for many forms of life."

Ancient photosynthesizers had to adapt to changes in the physical environment that they themselves had created, notes Lu. "The first part of the history of the Phanerozoic is increasing habitability for life, and then the second part is adaptation."

Read more at Science Daily

Virus that causes COVID-19 is widespread in wildlife, scientists find

SARS-CoV-2, the virus responsible for COVID-19, is widespread among wildlife species, according to Virginia Tech research published Monday (July 29, 2024) in Nature Communications. The virus was detected in six common backyard species, and antibodies indicating prior exposure to the virus were found in five species, with rates of exposure ranging from 40 to 60 percent depending on the species.

Genetic tracking in wild animals confirmed both the presence of SARS-CoV-2 and the existence of unique viral mutations with lineages closely matching variants circulating in humans at the time, further supporting human-to-animal transmission, the study found.

The highest exposure to SARS CoV-2 was found in animals near hiking trails and high-traffic public areas, suggesting the virus passed from humans to wildlife, according to scientists at the Fralin Biomedical Research Institute at VTC, the Department of Biological Sciences in Virginia Tech's College of Science, and the Fralin Life Sciences Institute.

The findings highlight the identification of novel mutations in SARS-CoV-2 in wildlife and the need for broad surveillance, researchers say. These mutations could be more harmful and transmissible, creating challenges for vaccine development.

The scientists stressed, however, that they found no evidence of the virus being transmitted from animals to humans, and people should not fear typical interactions with wildlife.

Investigators tested animals from 23 common Virginia species for both active infections and antibodies indicating previous infections. They found signs of the virus in deer mice, Virginia opossums, raccoons, groundhogs, Eastern cottontail rabbits, and Eastern red bats. The virus isolated from one opossum showed viral mutations that were previously unreported and can potentially impact how the virus affects humans and their immune response.

"The virus can jump from humans to wildlife when we are in contact with them, like a hitchhiker switching rides to a new, more suitable host," said Carla Finkielstein, professor of biological sciences at the Fralin Biomedical Research Institute at VTC and one of the paper's corresponding authors. "The goal of the virus is to spread in order to survive. The virus aims to infect more humans, but vaccinations protect many humans. So, the virus turns to animals, adapting and mutating to thrive in the new hosts."

SARS CoV-2 infections were previously identified in wildlife, primarily in white-tailed deer and feral mink. The Virginia Tech study significantly expands the number of species examined and the understanding of virus transmission to and among wildlife. The data suggests exposure to the virus has been widespread in wildlife and that areas with high human activity may serve as points of contact for cross-species transmission.

"This study was really motivated by seeing a large, important gap in our knowledge about SARS-CoV-2 transmission in a broader wildlife community," said Joseph Hoyt, assistant professor of Biological Sciences in Virginia Tech's College of Science and corresponding author on the paper. "A lot of studies to date have focused on white-tailed deer, while what is happening in much of our common backyard wildlife remains unknown."

The research team collected 798 nasal and oral swabs across in Virginia from animals either live-trapped in the field and released, or being treated by wildlife rehabilitation centers. The team also obtained 126 blood samples from six species. The locations were chosen to compare the presence of the virus in animals in sites with varying levels of human activity, from urban areas to remote wilderness.

The study also identified two mice at the same site on the same day with the exact same variant, indicating they either both got it from the same human, or one infected the other.

Researchers are not certain about the means of transmission from humans to animals. One possibility is wastewater, but the Virginia Tech scientists believe trash receptacles and discarded food are more likely sources.

"I think the big take home message is the virus is pretty ubiquitous," said Amanda Goldberg, a former postdoctoral associate in Hoyt's lab, who is the study's first author. "We found positives in a large suite of common backyard animals."

While this study focused on the state of Virginia, many of the species that tested positive are common wildlife found throughout North America. It is likely they are being exposed in other areas as well, and surveillance across a broader region is urgently needed, Hoyt said.

"The virus is indifferent to whether its host walks on two legs or four. Its primary objective is survival. Mutations that do not confer a survival or replication advantage to the virus will not persist and will eventually disappear," said Finkielstein, who is also director of the Virginia Tech Molecular Diagnostics Lab. The Roanoke lab was established in April 2020 to expand COVID-19 testing.

"We understood the critical importance of sequencing the genome of the virus infecting those species," Finkielstein said. "It was a monumental task that could only be accomplished by a talented group of molecular biologists, bioinformaticians, and modelers in a state-of-the-art facility. I am proud of my team and my collaborators, their professionalism, and everything they contributed to ensure our success."

Surveillance for these mutations should continue and not be dismissed, the scientists said. More research is needed about how the virus is transmitted from humans to wildlife, how it might spread within a species, and perhaps from one species to another.

"This study highlights the potentially large host range SARS-CoV-2 can have in nature and really how widespread it might be," Hoyt said. "There is a lot of work to be done to understand which species of wildlife, if any, will be important in the long-term maintenance of SARS-CoV-2 in humans."

Read more at Science Daily

Space-trekking muscle tests drugs for microgravity-induced muscle impairment

A gentle rumble ran under Ngan Huang's feet as a rocket carrying her research -- live, human muscle cells grown on scaffolds fixed on tiny chips -- lifted off, climbed, and disappeared into the sky to the International Space Station National Laboratory. These chips would help Huang better understand muscle impairment, often seen in astronauts and older adults, and test drugs to counter the condition.

Now, the results are back. Reporting in a study published July 25 in Stem Cell Reports, Huang's team showed that space-travelling muscle had metabolic changes that indicate impaired muscle regeneration and gene activities associated to age-related muscle loss called sarcopenia. But drug treatment partially prevented microgravity's adverse effects.

"Space is a really unique environment that accelerates qualities associated with aging and also impairs many healthy processes," says Huang, an associate professor at Stanford University. "Astronauts come back with muscle atrophy, or a reduction of muscle function, because the muscle isn't being actively used in the absence of gravity. As space travel becomes more common and available to civilians, it's important to understand what happens to our muscle in microgravity."

To understand the effects of microgravity on muscles, the researchers launched muscle chips -- bioengineered packages of oriented muscle cells on patterned biomaterials that mimic the structure of real muscles -- into space to grow for seven days under astronauts' care.

When the researchers compared muscle cells grown in microgravity to those grown on Earth, they found impaired muscle fiber formation. They also discovered differences in their gene activity and protein profile. Genes related to mitochondrial function, which muscles get their energy from, were compromised, and genes associated with fat formation were boosted. These findings suggest microgravity can lead to dysfunctions in muscle regeneration.

Space-traveled muscles also have gene activities that somewhat resemble muscles with sarcopenia, which most commonly affects people ages 60 and older.

"We think our research on muscle chips in microgravity may have broader implications on sarcopenia," says Huang. "Sarcopenia usually takes decades to develop on Earth, and we think that microgravity may have some ability to accelerate the disease process in orders of days."

In a proof-of-concept experiment to test the muscle chip for drug screening, the astronauts spiked the chips with drugs to treat sarcopenia or enhance muscle regeneration. The treatment partially mitigated some of the negative effects of microgravity on the muscles, preventing a metabolic shift to fat formation. Looking into gene activity patterns, the drug-treated muscle in microgravity is more similar to samples from Earth than untreated samples in microgravity.

Because space research is labor and resource intensive, the current study is a one-time experiment, and a limited number of samples were allowed to board the rocket. The scientists are now deploying equipment that simulates microgravity to overcome some of those limitations and aid their research in space. Huang's muscle chips are scheduled to embark on another space journey in 2025 to continue the research on identifying drugs for treating microgravity-induced impairment in muscle regeneration.

Read more at Science Daily

Countries need to co-operate on migration as climate crisis worsens

Humanity must rethink migration as the climate crisis drives rapid global changes, researchers say.

With significant migration expected -- and border policies hardening -- the researchers say the "time is ripe to highlight the benefits of collaboration between nations and regions."

By promoting the benefits of migration, especially in an era of ageing populations, global leaders could ensure a better future for people and societies.

The paper, published in the journal One Earth, comes from an international team of climate and social scientists including the universities of Wageningen, Exeter and Nanjing.

"Millions of people are projected to be displaced by sea-level rise in the next decades, and two billion could be exposed to extreme heat beyond their experience by the end of the century," said Professor Marten Scheffer, of Wageningen University.

"Ignoring or downplaying the inevitable global redistribution of people would lead to geo-political instability, and a polarised and fractured world.

"Instead, the international community must come together to rethink mobility and cultural integration to ensure a benign transition to this new world."

So far, most migration with significant climate dimensions has happened within countries, with people leaving areas affected by long-term decline in agricultural productivity or escaping conditions such as coastal erosion or extreme events.

While some large nations have different climate zones that can accommodate this, small countries do not.

The paper also warns that a "skewed distribution of wealth and associated power" makes it difficult for people to move, both within and between states.

Professor Tim Lenton, from Exeter's Global Systems Institute, said: "While many animal species are already changing their geographical distribution in response to climate change, and humans have done so for thousands of years, humanity now faces increasing barriers to this.

"Global warming exacerbates existing inequalities, making habitability a major political challenge of this century.

"Concrete cooperation is now needed to match migrant flows with demand for labour, to the benefit of the Global South and the developed world alike."

The paper says major reform of the food system, supported by movement of workers, could increase production while conserving nature -- especially if meat consumption is reduced in favour of plant-based diets.

Migration can therefore be a win-win for people and the climate, but leaders must make a positive case for economic benefits and effective integration.

"Playing up the social costs of migration appeals to national identity motivations, but fails to overcome problems from ageing populations," said Professor Neil Adger.

"Instead, leaders should focus on the economic and social benefits of new populations and effective integration, which benefits newcomers and original inhabitants alike.

Read more at Science Daily

Losing a loved one may speed up aging

Losing someone close, like a family member, can make you age faster, says a new study from Columbia University Mailman School of Public Health and the Butler Columbia Aging Center. The study found that people who lost a parent, partner, sibling, or child, showed signs of older biological age compared to those who hadn't experienced such losses. The research was published in JAMA Network Open.

Biological aging is the gradual decline in how well your cells, tissues, and organs function, leading to a higher risk of chronic diseases. Scientists measure this type of aging using DNA markers known as epigenetic clocks.

"Few studies have looked at how losing a loved one at different stages of life affects these DNA markers, especially in study samples that represent the U.S .population," said Allison Aiello, PhD, the James S. Jackson professor of health longevity in Epidemiology and the study's lead author. "Our study shows strong links between losing loved ones across the life course from childhood to adulthood and faster biological aging in the U.S."

The study, a collaboration with the Carolina Population Center at UNC Chapel Hill, suggests that the impact of loss on aging can be seen long before middle age and may contribute to health differences among racial and ethnic groups.

The researchers used data from the National Longitudinal Study of Adolescent to Adult Health, which started in 1994-95. It followed participants from their teenage years into adulthood.

To measure familial loss during childhood or adolescence from the longitudinal study, Aiello and colleagues followed participants through various waves, and aging timeframes. Wave I surveyed 20,745 adolescents in grades 7-12, most of whom were aged 12-19. Participants have been followed ever since. Wave V took place between 2016 and 2018 and completed interviews with 12,300 of the original participants. In the latest wave, between 2016 and 2018, participants were invited for an additional home exam where a blood sample of the nearly 4,500 visited was provided for DNA testing.

The study looked at losses experienced during childhood or adolescence (up to 18 years old) and adulthood (19 to 43 years old). They also examined the number of losses experienced across this time period. Biological aging data were assessed from blood DNA methylation using epigenetic clocks including DunedinPACE which was developed by by Aiello's Aging Center colleague and study co-author Dan Belsky and his collaborators at Duke University.

Nearly 40 percent of participants experienced at least one loss in adulthood between the ages of 33 and 43. Parental loss was more common in adulthood versus in childhood and adolescence (27 percent versus 6 percent). A larger proportion of Black (57 percent) and Hispanic (41 percent) participants experienced at least one loss compared to White participants (34 percent).

People who experienced two or more losses had older biological ages according to several epigenetic clocks. Experiencing two or more losses in adulthood was more strongly linked to biological aging than one loss and significantly more so than no losses.

"The connection between losing loved ones and health problems throughout life is well-established," Aiello noted. "But some stages of life might be more vulnerable to the health risks associated with loss and the accumulation of loss appears to be a significant factor."

For example, losing a parent or sibling early in life can be very traumatic, often leading to mental health issues, cognitive problems, higher risks of heart disease, and a greater chance of dying earlier. Losing a close family member at any age poses health risks, and repeated losses can increase the risks of heart disease, mortality, and dementia; and impacts may persist or become apparent long after the event.

Aiello and her co-authors emphasize that while loss at any age can have long-lasting health impacts, the effects might be more severe during key developmental periods like childhood or early adulthood. "We still don't fully understand how loss leads to poor health and higher mortality, but biological aging may be one mechanism as suggested in our study. Future research should focus on finding ways to reduce disproportionate losses among vulnerable groups. For those who experience loss, providing resources for coping and addressing the trauma is essential. ," Aiello concluded.

Read more at Science Daily

New clues point towards how exercise reduces symptoms of depression

The processes in the brain and body through which physical exercise reduces depressive symptoms have been explored by UCL researchers.

Depression is the leading cause of disability worldwide and is associated with disruptions to several brain and psychological processes, including impaired learning and memory. Physical activity, especially aerobic exercise, has been found to reduce depressive symptoms, but until now the processes behind this have been poorly understood.

In a new review article published in Translational Psychiatry, researchers propose a novel hypothesis to understand the antidepressant effects of exercise. They believe that the process may hinge on motivation, which is very important for alleviating a number of symptoms of depression, such as anhedonia (a lack of interest or joy in life's experiences), low energy and 'brain fog'.

The team summarised research papers that explored the mechanisms of depression in both humans and animals and concluded that depression, especially anhedonia, is associated with elevated inflammation (caused by the body's immune response). Importantly, inflammation is also linked to disrupted dopamine transmission. These biological changes may represent key processes leading to changes in motivation, and in particular a lower willingness to exert physical or mental effort.

Meanwhile, exercise reduces inflammation, boosts dopamine function, and enhances motivation. The researchers believe that this could be an important reason as to why exercise exerts an antidepressant effect.

Lead author, Dr Emily Hird (UCL Institute of Cognitive Neuroscience) said: "The antidepressant effect of aerobic exercise has been convincingly demonstrated through randomised controlled trials, but its mechanism is not well understood. This is, in part, because it likely involves a variety of biological and psychological processes.

"For example, alongside its positive effect on inflammation, dopamine and reward processing, exercise also reduces oxidative stress and improves self-esteem and self-efficacy.

"However, we are proposing that exercise -- particularly aerobic activities that make you sweaty and out of breath -- decreases inflammation and boosts dopamine transmission, which in turn increases the desire to exert effort, and therefore boosts motivation generally."

The team hope that this understanding of how exercise reduces symptoms of depression will help to inform the development of new treatment strategies -- such as personalised exercise programmes.

Dr Hird said: "Understanding the mechanisms that underly the antidepressant effects of physical activity in depression could also inform our understanding of the mechanisms causing depression and the development of novel intervention strategies, in particular personalised intervention, and social prescribing."

To further test their hypothesis, the researchers advise that large randomised controlled trials need to be conducted that assess the antidepressant effects of exercise, whilst also measuring the effect on variables including inflammation, dopamine transmission and motivation.

It would also be important to investigate any potential barriers to exercise.

Dr Hird said: "Addressing barriers to exercise -- particularly in people with depression -- is crucial, as regular physical activity may be able to alleviate symptoms, enhance mood and empower individuals on their path to recovery. As part of this, finding strategies to encourage exercise is key."

Read more at Science Daily