Two of the Milky Way's earliest building blocks identified

Astronomers have identified what could be two of the Milky Way's earliest building blocks: Named "Shakti" and "Shiva," these appear to be the remnants of two galaxies that merged between 12 and 13 billion years ago with an early version of the Milky Way, contributing to our home galaxy's initial growth. The new find is the astronomical equivalent of archeologists identifying traces of an initial settlement that grew into a large present-day city. It required combining data for nearly 6 million stars from ESA's Gaia mission with measurements from the SDSS survey. The results have been published in the Astrophysical Journal.

The early history of our home galaxy, the Milky Way, is one of joining smaller galaxies, which makes for fairly large building blocks. Now, Khyati Malhan and Hans-Walter Rix of the Max Planck Institute for Astronomy have succeeded in identifying what could be two of the earliest building blocks that can still be recognized as such today: proto-galactic fragments that merged with an early version of our Milky Way between 12 and 13 billion years ago, at the very beginning of the era of galaxy formation in the Universe. The components, which the astronomers have named Shakti and Shiva, were identified by combining data from ESA's astrometry satellite Gaia with data from the SDSS survey. For astronomers, the result is the equivalent of finding traces of an initial settlement that grew into a large present-day city.

Tracing the origins of stars that came from other galaxies

When galaxies collide and merge, several processes happen in parallel. Each galaxy carries along its own reservoir of hydrogen gas. Upon collision, those hydrogen gas clouds are destabilized, and numerous new stars are formed inside. Of course, the incoming galaxies also already have their own stars, and in a merger, stars from the galaxies will mingle. In the long run, such "accreted stars" will also account for some of the stellar population of the newly-formed combined galaxy. Once the merger is completed, it might seem hopeless to identify which stars came from which predecessor galaxy. But in fact, at least some ways of tracing back stellar ancestry exist.

Help comes from basic physics. When galaxies collide and their stellar populations mingle, most of the stars retain very basic properties, which are directly linked to the speed and direction of the galaxy in which they originated. Stars from the same pre-merger galaxy share similar values for both their energy and what physicists call angular momentum -- the momentum associated with orbital motion or rotation. For stars moving in a galaxy's gravitational field, both energy and angular momentum are conserved: they remain the same over time. Look for large groups of stars with similar, unusual values for energy and angular momentum -- and chances are, you might find a merger remnant.

Additional pointers can assist identification. Stars that formed more recently contain more heavier elements, what astronomers call "metals," than stars that formed a long time ago. The lower the metal content ("metallicity"), the earlier the star presumably formed. When trying to identify stars that already existed 13 billion years ago, one should look for stars with very low metal content ("metal-poor").

Virtual excavations in a large data set

Identifying the stars that joined our Milky Way as parts of another galaxy has only become possible comparatively recently. It requires large, high-quality data sets, and the analysis involves sifting the data in clever ways so as to identify the searched-for class of objects. This kind of data set has only been available for a few years. The ESA astrometry satellite Gaia provides an ideal data set for this kind of big-data galactic archeology. Launched in 2013, it has produced an increasingly accurate data set over the past decade, which by now includes positions, changes in position and distances for almost 1.5 billion stars within our galaxy.

Gaia data revolutionized studies of the dynamics of stars in our home galaxy, and has already led to the discovery of previously unknown substructures. This includes the so-called Gaia Enceladus/Sausage stream, a remnant of the most recent larger merger our home galaxy has undergone, between 8 and 11 billion years ago. It also includes two structures identified in 2022: the Pontus stream identified by Malhan and colleagues and the "poor old heart" of the Milky Way identified by Rix and colleagues. The latter is a population of stars that newly formed during the initial mergers that created the proto-Milky Way, and continue to reside in our galaxy's central region.

Traces of Shakti and Shiva

For their present search, Malhan and Rix used Gaia data combined with detailed stellar spectra from the Sloan Digital Sky Survey (DR17). The latter provide detailed information about the stars' chemical composition. Malhan says: "We observed that, for a certain range of metal-poor stars, stars were crowded around two specific combinations of energy and angular momentum."

In contrast with the "poor old heart," which was also visible in those plots, the two groups of like-minded stars had comparatively large angular momentum, consistent with groups of stars that had been part of separate galaxies which had merged with the Milky Way. Malhan has named these two structures Shakti and Shiva, the latter one of the principal deities of Hinduism and the former a female cosmic force often portrayed as Shiva's consort.

Their energy and angular momentum values, plus their overall low metallicity on par with that of the "poor old heart," makes Shakti and Shiva good candidates for some of the earliest ancestors of our Milky Way. Rix says: "Shakti and Shiva might be the first two additions to the 'poor old heart' of our Milky Way, initiating its growth towards a large galaxy."

Read more at Science Daily

James Webb Space Telescope captures the end of planet formation

Scientists believe that planetary systems like our solar system contain more rocky objects than gas-rich ones. Around our sun, these include the inner planets -- Mercury, Venus, Earth and Mars -- the asteroid belt and the Kuiper belt objects such as Pluto.

Jupiter, Saturn, Uranus and Neptune, on the other hand, contain mostly gas. But scientists also have known for a long time that planet-forming disks start out with 100 times more mass in gas than solids, which leads to a pressing question: When and how does most of the gas leave a nascent planetary system?

A new study led by Naman Bajaj at the University of Arizona Lunar and Planetary Laboratory, published in the Astronomical Journal, provides answers. Using the James Webb Space Telescope, or JWST, the team obtained images from such a nascent planetary system -- also known as a circumstellar disk -- in the process of actively dispersing its gas into surrounding space.

"Knowing when the gas disperses is important as it gives us a better idea of how much time gaseous planets have to consume the gas from their surroundings," said Bajaj, a second-year doctoral student at UArizona's Lunar and Planetary Laboratory. "With unprecedented glimpses into these disks surrounding young stars, the birthplaces of planets, JWST helps us uncover how planets form."

During the very early stages of planetary system formation, planets coalesce in a spinning disk of gas and tiny dust around the young star, according to Bajaj. These particles clump together, building up into bigger and bigger chunks called planetesimals. Over time, these planetesimals collide and stick together, eventually forming planets. The type, size and location of planets that form depend on the amount of material available and how long it remains in the disk.

"So, in short, the outcome of planet formation depends on the evolution and dispersal of the disk," Bajaj said.

At the heart of this discovery is the observation of T Cha, a young star -- relative to the sun, which is about 4.6 billion years old -- enveloped by an eroding circumstellar disk notable for a vast dust gap, spanning approximately 30 astronomical units, or au, with one au being the average distance between the Earth and the sun.

Bajaj and his team were able, for the first time, to image the disk wind, as the gas is referred to when it slowly leaves the planet-forming disk. The astronomers took advantage of the telescope's sensitivity to light emitted by an atom when high-energy radiation -- for example, in starlight -- strips one or more electrons from its nucleus. This is known as ionization, and the light emitted in the process can be used as a sort of chemical "fingerprint" -- in the case of the T Cha system, tracing two noble gases, neon and argon. The observations also mark the first time a double ionization of argon has been detected in a planet-forming disk, the team writes in the paper.

"The neon signature in our images tells us that the disk wind is coming from an extended region away from the disk," Bajaj said. "These winds could be driven either by high-energy photons -- essentially the light streaming from the star -- or by the magnetic field that weaves through the planet-forming disk."

In an effort to differentiate between the two, the same group, this time led by Andrew Sellek, a postdoctoral researcher at Leiden University in the Netherlands, performed simulations of the dispersal driven by stellar photons, the intense light streaming from the young star. They compared these simulations to the actual observations and found dispersal by high-energy stellar photons can explain the observations, and hence cannot be excluded as a possibility. That study concluded that the amount of gas dispersing from the T Cha disk every year is equivalent to that of Earth's moon. These results will be published in a companion paper, currently under review with the Astronomical Journal.

While neon signatures had been detected in many other astronomical objects, they weren't known to originate in low-mass planet-forming disks until first discovered in 2007 with JWST's predecessor, NASA's Spitzer Space Telescope, by Ilaria Pascucci, a professor at LPL who soon identified them as a tracer of disk winds. Those early findings transformed research efforts focused on understanding gas dispersal from circumstellar disks. Pascucci is the principal investigator on the most recent observing project and a co-author on the publications reported here.

"Our discovery of spatially resolved neon emission -- and the first detection of double ionized argon -- using the James Webb Space Telescope could become the next step towards transforming our understanding of how gas clears out of a planet-forming disk," Pascucci said. "These insights will help us get a better idea of the history and impact on our own solar system."

In addition, the group has also discovered that the inner disk of T Cha is evolving on very short timescales of decades; they found that the spectrum observed by JWST differs from the earlier spectrum detected by Spitzer. According to Chengyan Xie, a second-year doctoral student at LPL who leads this in-progress work, this mismatch could be explained by a small, asymmetric disk inside of T Cha that has lost some of its mass in the short 17 years that have elapsed between the two observations.

"Along with the other studies, this also hints that the disk of T Cha is at the end of its evolution," Xie said. "We might be able to witness the dispersal of all the dust mass in T Cha's inner disk within our lifetime."

Read more at Science Daily

Scientists uncover evidence that microplastics are contaminating archaeological remains

Researchers have for the first time discovered evidence of microplastic contamination in archaeological soil samples.

The team discovered tiny microplastic particles in deposits located more than seven metres deep, in samples dating back to the first or early second century and excavated in the late 1980s.

Preserving archaeology in situ has been the preferred approach to managing historical sites for a generation.

However, the research team say the findings could prompt a rethink, with the tiny particles potentially compromising the preserved remains.

Microplastics are small plastic particles, ranging from 1μm (one thousandth of a millimetre) to 5mm.

They come from a wide range of sources, from larger plastic pieces that have broken apart, or resin pellets used in plastic manufacturing which were frequently used in beauty products up until around 2020.

The study, published in the journal Science of the Total Environment, was carried out by the universities of York and Hull and supported by the educational charity York Archaeology.

Professor John Schofield from the University of York's Department of Archaeology, said: "This feels like an important moment, confirming what we should have expected: that what were previously thought to be pristine archaeological deposits, ripe for investigation, are in fact contaminated with plastics, and that this includes deposits sampled and stored in the late 1980s.

"We are familiar with plastics in the oceans and in rivers. But here we see our historic heritage incorporating toxic elements. To what extent this contamination compromises the evidential value of these deposits, and their national importance is what we'll try to find out next."

David Jennings, chief executive of York Archaeology, added: "We think of microplastics as a very modern phenomenon, as we have only really been hearing about them for the last 20 years, when Professor Richard Thompson revealed in 2004 that they have been prevalent in our seas since the 1960s with the post-war boom in plastic production,"

"This new study shows that the particles have infiltrated archaeological deposits, and like the oceans, this is likely to have been happening for a similar period, with particles found in soil samples taken and archived in 1988 at Wellington Row in York."

The study identified 16 different microplastic polymer types across both contemporary and archived samples.

"Where this becomes a concern for archaeology is how microplastics may compromise the scientific value of archaeological deposits. Our best-preserved remains -- for example, the Viking finds at Coppergate -- were in a consistent anaerobic waterlogged environment for over 1000 years, which preserved organic materials incredibly well. The presence of microplastics can and will change the chemistry of the soil, potentially introducing elements which will cause the organic remains to decay. If that is the case, preserving archaeology in situ may no longer be appropriate," added David Jennings.

Read more at Science Daily

Researchers propose a new way to identify when babies become conscious

Academics are proposing a new and improved way to help researchers discover when consciousness emerges in human infancy.

When over the course of development do humans become conscious? When the seventeenth-century French philosopher René Descartes was asked about infant consciousness by his critics, he eventually suggested that infants might have thoughts, albeit ones that are simpler than those of adults. Hundreds of years later, the issue of when human beings become conscious is a question which remains a challenge for psychologists and philosophers alike.

But now, in response to a recent article in Trends in Cognitive Sciences, two academics from the University of Birmingham have suggested an improved way to help scientists and researchers identify when babies become conscious.

In a Letter to the Editor, also published in Trends in Cognitive Sciences, Dr Henry Taylor, Associate Professor of Philosophy, and Andrew Bremner, Professor of Developmental Psychology, have explored a new approach which is being proposed, that involves identifying markers of consciousness in adults, and then measuring when babies start to exhibit larger numbers of these in development.

Dr Taylor says: "For example, imagine that in adults, we know that a certain very specific behaviour, or a specific pattern of brain activation always comes along with consciousness. Then, if we can identify when this behaviour or brain activation arises in babies, we have good reason to think that this is when consciousness emerges in babies. Behaviours and brain activations like this are what we call 'markers' of consciousness."

This kind of approach is desperately needed since babies (unlike adults) cannot tell you what they are conscious of. Professor Bremner said: "It is really hard to establish when babies become conscious. This is mostly because infants can't report their experiences and, as most parents will know, can be rather uncooperative particularly when it comes to experimental tasks. As we can't just ask babies when they become conscious, the best approach is to try to identify a broad range of markers of consciousness, which appear in early development and late development, and then group them together, this could help us identify when consciousness emerges."

In the recent article the researchers (Prof. Tim Bayne and colleagues) suggested four specific markers of consciousness, some of which are present in the late stages of gestation, and others which are found in early infancy. Based on this, the study argues that consciousness emerges early (from the last prenatal trimester).

But Professor Bremner and Dr Taylor say that this ignores other markers of consciousness. Previous research has identified a separate cluster of markers. These include:

• Pointing (bringing a social partner's attention to an object and checking). • Intentional control (intentional means-end coordination of actions -- e.g., pulling a support to retrieve a distal object). • Explicit memory (deferred imitation of actions).

Dr Taylor said: "One of the complicated issues is that it does not look like all the markers point to the same age for the emergence of consciousness. The ones mentioned by Bayne and colleagues suggest somewhere between the third trimester of pregnancy and early infancy, but other markers suggest the age might be around one year old. In fact, at the really extreme end, some markers only emerge at around 3-4 years. Because there are so many different markers of consciousness which appear in early and late development it is extremely hard to come to a conclusion."

Professor Bremner concluded: "We propose that a broad approach to markers, including those that emerge in early and late stage, is needed. We also recommend that a range of developmental models of the onset of consciousness should be considered. For instance, it may be that some markers emerge in one cluster in early development, with others in a later cluster. As well as this there may be a continuous and gradual emergence of certain markers stretching over gestation and throughout early life.

Read more at Science Daily

Astrophysicist's research could provide a hint in the search for dark matter

Dark matter is one of science's greatest mysteries. Although it is believed to make up about 85 percent of the cosmos, scientists know very little about its fundamental nature. Research by Clemson University postdoctoral fellow Alex McDaniel provides some of the most stringent constraints on the nature of dark matter yet. It also revealed a small hint of a signal that, if real, could be confirmed in the next decade or so.

Dark matter is one of science's greatest mysteries.

It doesn't absorb, reflect or emit light, so we can't see it. But its presence is implied by the gravitational effects it appears to have on galaxies.

Although dark matter makes up about 85 percent of the cosmos, scientists know very little about its fundamental nature.

Theories abound, and research by Clemson University postdoctoral fellow Alex McDaniel provides some of the most stringent constraints on the nature of dark matter yet.

His research also reveals a small hint of a signal that, if real, could be confirmed sometime in the next decade or so.

"With data collection and new discoveries in the future, this small hint could potentially turn into a very concrete detection of a dark matter model," McDaniel said.

Detecting dark matter would be groundbreaking.

"Dark matter is one of the most important things in astrophysics, and we know next to nothing about it. Discovering it will be a tremendous breakthrough," said Marco Ajello, an associate professor in the Clemson Department of Physics and Astronomy and McDaniel's adviser.

"Whoever discovers may win a Nobel Prize. It's that big."

In this work, McDaniel and collaborators were searching dwarf galaxies for dark matter that self-annihilates into ordinary matter and gamma rays, a form of light at the highest energy levels.

Dwarf galaxies are ideal for study because they are small, rich in dark matter and mostly lack other astrophysics phenomena such as gas, dust and supernova that could contaminate the findings.

"We look for these because, ideally, they give us a clean signal or allow us to rule out certain particle theories," McDaniel said.

Some models predict that dark matter has a certain mass or cross section, which is the probability of a specific event occurring due to the interaction of particles.

That would determine what researchers would expect to see in gamma rays.

If they don't see that, they can rule out those masses and cross sections, he said.

"In this paper, we do more ruling out, saying that dark matter can't have those masses or cross section," said Chris Karwin, a former postdoc at Clemson and a co-author of the study.

Karwin is now a postdoctoral fellow at the NASA Goddard Space Flight Center.

"But compared to previous studies, we do start to see a hint of something that might be a signal from these systems."

McDaniel's study uses the larger samples that include additional discovered dwarf galaxies and larger amounts of data than previous studies.

He included about 50 dwarf galaxies in his study but said that with new, more powerful telescopes coming online in the near future, he expects that number to increase to 150-200.

"The new telescopes are basically dwarf galaxy detectors," he said.

Read more at Science Daily

Say hello to biodegradable microplastics

Microplastics are tiny, nearly indestructible fragments shed from everyday plastic products. As we learn more about microplastics, the news keeps getting worse. Already well-documented in our oceans and soil, we're now discovering them in the unlikeliest of places: our arteries, lungs and even placentas. Microplastics can take anywhere from 100 to 1,000 years to break down and, in the meantime, our planet and bodies are becoming more polluted with these materials every day.

Finding viable alternatives to traditional petroleum-based plastics and microplastics has never been more important. New research from scientists at the University of California San Diego and materials-science company Algenesis shows that their plant-based polymers biodegrade -- even at the microplastic level -- in under seven months. The paper, whose authors are all UC San Diego professors, alumni or former research scientists, appears in Nature Scientific Reports.

"We're just starting to understand the implications of microplastics. We've only scratched the surface of knowing the environmental and health impacts," stated Professor of Chemistry and Biochemistry Michael Burkart, one of the paper's authors and an Algenesis co-founder. "We're trying to find replacements for materials that already exist, and make sure these replacements will biodegrade at the end of their useful life instead of collecting in the environment. That's not easy."

"When we first created these algae-based polymers about six years ago, our intention was always that it be completely biodegradable," said another of the paper's authors, Robert Pomeroy, who is also a professor of chemistry and biochemistry and an Algenesis co-founder. "We had plenty of data to suggest that our material was disappearing in the compost, but this is the first time we've measured it at the microparticle level."

Putting it to the test

To test its biodegradability, the team ground their product into fine microparticles, and used three different measurement tools to confirm that, when placed in a compost, the material was being digested by microbes.

The first tool was a respirometer. When the microbes break down compost material, they release carbon dioxide (CO2), which the respirometer measures. These results were compared to the breakdown of cellulose, which is considered the industry standard of 100% biodegradability. The plant-based polymer matched the cellulose at almost one hundred percent.

Next the team used water flotation. Since plastics are not water soluble and they float, they can easily be scooped off the surface of water. At intervals of 90 and 200 days, almost 100% of the petroleum-based microplastics were recovered, meaning none of it had biodegraded. On the other hand, after 90 days, only 32% of the algae-based microplastics were recovered, showing that more than two thirds of it had biodegraded. After 200 days, only 3% was recovered indicating that 97% of it had disappeared.

The last measurement involved chemical analysis via gas chromatography/mass spectrometry (GCMS), which detected the presence of the monomers used to make the plastic, indicating that the polymer was being broken to its starting plant materials. Scanning-electron microscopy further showed how microorganisms colonize the biodegradable microplastics during composting.

"This material is the first plastic demonstrated to not create microplastics as we use it," said Stephen Mayfield, a paper coauthor, School of Biological Sciences professor and co-founder of Algenesis. "This is more than just a sustainable solution for the end-of-product life cycle and our crowded landfills. This is actually plastic that is not going to make us sick."

Creating an eco-friendly alternative to petroleum-based plastics is only one part of the long road to viability. The ongoing challenge is to be able to use the new material on pre-existing manufacturing equipment that was originally built for traditional plastic, and here Algenesis is making progress. They have partnered with several companies to make products that use the plant-based polymers developed at UC San Diego, including Trelleborg for use in coated fabrics and RhinoShield for use in the production of cell phone cases.

"When we started this work, we were told it was impossible," stated Burkart. "Now we see a different reality. There's a lot of work to be done, but we want to give people hope. It is possible."

Read more at Science Daily

Your dog understands that some words 'stand for' objects

It's no surprise that your dog can learn to sit when you say "sit" and come when called. But a study appearing March 22 in the journal Current Biology has made the unexpected discovery that dogs generally also know that certain words "stand for" certain objects. When dogs hear those words, brain activity recordings suggest they activate a matching mental representation in their minds.

"Dogs do not only react with a learned behavior to certain words," says Marianna Boros of the Department of Ethology at the Eötvös Loránd University, Budapest, Hungary, one of the paper's co-first authors. "They also don't just associate that word with an object based on temporal contiguity without really understanding the meaning of those words, but they activate a memory of an object when they hear its name."

Word understanding tests with individuals who do not speak, such as infants and animals, usually require active choice, the researchers say. They're asked to show or get an object after hearing its name. Very few dogs do well on such tests in the lab, often fetching objects correctly at a rate expected by chance.

The researchers wanted to look closer at dogs' implicit understanding of object words by measuring brain activity using non-invasive EEG without asking them to act. The idea was that this might offer a more sensitive measure of their understanding of language.

In their studies, they had 18 dog owners say words for toys their dogs knew and then present the objects to them. Sometimes they presented the matching toy, while other times they would present an object that didn't match. For example, an owner would say, "Zara, look, the ball," and present the object while the dog's brain activity was captured on EEG.

The brain recording results showed a different pattern in the brain when the dogs were shown a matching object versus a mismatched one. That's similar to what researchers have seen in humans and is widely accepted as evidence that they understand the words. The researchers also found a greater difference in those patterns for words that dogs knew better, offering further support for their understanding of object words. Interestingly, while the researchers thought this ability might depend on having a large vocabulary of object words, their findings showed that it doesn't.

"Because typical dogs learn instruction words rather than object names, and there are only a handful of dogs with a large vocabulary of object words, we expected that dogs' capacity for referential understanding of object words will be linked to the number of object words they know; but it wasn't," says Lilla Magyari, also of Eötvös Loránd University and University of Stavanger and the other co-first author.

"It doesn't matter how many object words a dog understands -- known words activate mental representations anyway, suggesting that this ability is generally present in dogs and not just in some exceptional individuals who know the names of many objects," Boros added.

The discovery that dogs as a species may generally have a capacity to understand words in a referential way, just as humans do, might reshape the way scientists think about the uniqueness of how humans use and understand language, the researchers say. That has important implications for theories and models of language evolution. For dog owners, it's also an important realization.

"Your dog understands more than he or she shows signs of," Magyari says. "Dogs are not merely learning a specific behavior to certain words, but they might actually understand the meaning of some individual words as humans do."

Read more at Science Daily

Study reveals 'cozy domesticity' of prehistoric stilt-house dwellers in England's ancient marshland

A major report on the remains of a stilt village that was engulfed in flames almost 3,000 years ago reveals in unprecedented detail the daily lives of England's prehistoric fenlanders.

Must Farm, a late Bronze Age settlement, dates to around 850BC, with University of Cambridge archaeologists unearthing four large wooden roundhouses and a square entranceway structure -- all of which had been constructed on stilts above a slow-moving river.

The entire hamlet stood approximately two metres above the riverbed, with walkways bridging some of the main houses, and was surrounded by a two-metre-high fence of sharpened posts.

The settlement was less than a year old when it was destroyed by a catastrophic fire, with buildings and their contents collapsing into the muddy river below. The combination of charring and waterlogging led to exceptional preservation. The site has been described as "Britain's Pompeii."

Years of research conducted on thousands of artefacts from the site have now shown that early Fen folk had surprisingly comfortable lifestyles, with domestic layouts similar to modern homes, meals of "honey-glazed venison" and clothes of fine flax linen, and even a recycling bin.

The settlement-on-stilts also contained a stack of spears with shafts over three metres long, as well as a necklace with beads from as far away as Denmark and Iran, and a human skull rendered smooth by touch, perhaps a memento of a lost loved one.

The Cambridge archaeologists say the site provides a unique "blueprint" for the circular architecture, home interiors and overall domesticity of those who inhabited the swampy fenland of East Anglia some eight centuries before Romans set foot on British shores.

Full findings from the Must Farm site -- excavated by the Cambridge Archaeological Unit (CAU) in 2015-16 after its discovery on the edge of Whittlesey near Peterborough -- are published in two reports, both made available by Cambridge's McDonald Institute for Archaeological Research.

"These people were confident and accomplished home-builders. They had a design that worked beautifully for an increasingly drowned landscape," said CAU's Mark Knight, report co-author and excavation director.

"While excavating the site there was a sense that its Bronze Age residents had only just left. You could almost see and smell their world, from the glint of metal tools hanging on wattled walls to the sharp milkiness of brewed porridge."

'Mirror' of ancient home interiors

The ruins of five structures were uncovered, along with walkways and fencing, but the original settlement was likely twice as big -- half the site was removed by 20th century quarrying -- with researchers saying it may have held up to sixty occupants in family units.

The river running underneath the community would have been shallow, sluggish and thick with vegetation. This cushioned the scorched remains where they fell, creating an archaeological "mirror" of what had stood above -- allowing researchers to map the layout of the structures.

One of the main roundhouses, with almost fifty square metres of floor space, appeared to have distinct activity zones comparable to rooms in a modern home.

"Conducting research on Must Farm is a bit like getting an estate agent's tour of a Bronze Age stilt house," said David Gibson, report co-author and Archaeological Manager at CAU.

Ceramic and wooden containers, including tiny cups, bowls, and large storage jars, were found in the northeast quadrant of "Structure One," the location of a kitchen. Some pots were even nested: designed to stack inside one another to save space.

Metal tools were stored along the building's eastern side, while the empty northwest area was probably reserved for sleeping. The southeast space had lots of cloth fragments, along with bobbins and loom weights. This was close to a likely entrance, where extra light would have helped with textile work.

The roundhouse's southwest quadrant was reserved for keeping lambs indoors. There was no evidence of humans dying in the fire, but several young sheep had been trapped and burnt alive.

Skeletal remains showed the lambs were three to six months old, suggesting the settlement was destroyed sometime in late summer or early autumn. Evidence that the wooden architecture was still "green" confirms construction took place around nine months to a year earlier.

Tool kits, textiles and a token of good luck

Household inventories were remarkably consistent. All the roundhouses contained a metalwork "tool kit" that included sickles (crop-harvesting blades) along with axes and curved "gouges" used to hack and chisel wood, as well as hand-held razors for cutting hair.

Most buildings had objects for making textiles, from spindle whorls to thread bobbins, although the distribution suggests that "spinning" -- the process of twisting fibres together -- was conducted in three of the roundhouses, but Structure One was where this yarn got converted to fabrics.

The textiles are the finest of this period found in Europe, with details such as "pile tufts" that would have given garments a soft, almost velvety feel, and "tubular selvedge" for neat seams and hems.

Each roundhouse roof had three layers: insulating straw topped by turf and completed with clay -- making them warm and waterproof but still well ventilated. "In a freezing winter, with winds cutting across the Fens, these roundhouses would have been pretty cosy," said CAU project archaeologist Dr Chris Wakefield.

Structure Four, a smaller square building, may also have acted as the settlement's entrance. A large wooden bucket had been kept within, containing several damaged bronze objects and worn axe-heads, waiting to be smelted down and recycled into new tools.

Encircling the footprint of each roundhouse were "middens," haloes of rubbish dumped from the stilt village above, included broken pots, butchered animal bone, and "coprolites" or fossilised faeces. Some human coprolites had parasite eggs, suggesting inhabitants struggled with intestinal worms.

One item, however, had been placed in the silt directly beneath Structure One: an intact hafted axe, perhaps a token of good fortune, or an offering to some kind of spirit on completion of the build.

'Meaty porridge'

Despite millennia in the mud, many artefacts still bore traces of daily life -- along with its sudden interruption as inhabitants abandoned their possessions to escape the blaze.

For example, a pottery bowl with the finger-marks of its maker captured in the clay was found still holding its final meal: a wheat-grain porridge mixed with animal fats (possibly goat or red deer). The wooden spatula used for stirring was resting against the inside of the bowl.

"It appears the occupants saved their meat juices to use as toppings for porridge," said Dr Chris Wakefield. "The site is providing us with hints of recipes for Bronze Age breakfasts and roast dinners."

"Chemical analyses of the bowls and jars showed traces of honey along with ruminant meats such as deer, suggesting these ingredients were combined to create a form of prehistoric honey-glazed venison."

The stilt-house dwellers even had favourite cuts of meat, often only bringing the forelegs of a boar back for roasting, for example. Preferred aquatic dishes included pike and bream.

Several small dog skulls suggest the animals were kept domestically, perhaps as pets but also to help flush out prey on a hunt. Dog coprolites show they fed on scraps from their owners' meals.

Must Farm's residents used the local woodlands -- evidence suggests within a two-mile radius -- to hunt boar and deer, graze sheep, and harvest crops such as wheat and flax as well as wood for construction. Waterways were vital for transporting all these materials.

The remains of nine log-boats, canoes hollowed from old tree trunks, were found upstream, dating from across the Bronze and into the Iron Age, included some that were contemporary to Must Farm.

"Boat journeys through reed swamps to the woodlands would have been made many times during the site's short life," said Wakefield. "In summer, that meant traversing clouds of mosquitos."

Much of what was retrieved from Must Farm were everyday items, the Bronze Age equivalent to the TV remotes and coffee mugs of our own lives. However, some items would have been precious.

A necklace of beads made from glass, amber, siltstone and shale had been lost in the fire. In fact, decorative beads were found right across the site. All but one of Must Farm's 49 glass beads came from far-flung places, including Northern and Eastern Europe, and even the Middle East.

"Such items would gradually make their way across thousands of miles in a long series of small trades," said Wakefield.

Up in flames…

The researchers say that, while the Bronze Age could be violent, and aspects of the site's structure are clearly defensive, its location may be as much to do with resources. Spears found on site, up to 3.4 metres in length, as well as swords, were as likely to be used in animal hunts as on rival groups.

A few human remains were recovered, including the skull of an adult woman polished by repeated touch -- a sign this may have been a keepsake of love rather than war.

"The cause of the fire that tore through the settlement will probably never be known," said CAU's David Gibson. "Some argue it may have come under attack, as the occupants never returned for their goods, which would have been fairly easy to retrieve from the shallow waters."

However, others think it more likely to have been an accident. If an internal fire took hold in one of the roundhouses, it would spread between the tightknit structures within minutes.

Added Gibson: "A settlement like this would have had a shelf-life of maybe a generation, and the people who built it had clearly constructed similar sites before. It may be that after the fire, they simply started again."

"There is every possibility that the remains of many more of these stilted settlements are buried across Fenland, waiting for us to find them."

Read more at Science Daily

Scientists find one of the most ancient stars that formed in another galaxy

The first generation of stars transformed the universe. Inside their cores, simple hydrogen and helium fused into a rainbow of elements. When these stars died, they exploded and sent these new elements across the universe. The iron running in your veins and the calcium in your teeth and the sodium powering your thoughts were all born in the heart of a long-dead star.

No one has been able to find one of those first generation of stars, but scientists have announced a unique finding: a star from the second generation that originally formed in a different galaxy from ours.

"This star provides a unique window into the very early element-forming process in galaxies other than our own," said Anirudh Chiti, a University of Chicago postdoctoral fellow and first author on a paper announcing the findings. "We have built up an idea of the how these stars that were chemically enriched by the first stars look like in the Milky Way, but we don't yet know if some of these signatures are unique, or if things happened similarly across other galaxies."

The paper was published March 20 in Nature Astronomy.

'Fishing needles out of haystacks'

Chiti specializes in what is called stellar archaeology: Reconstructing how the earliest generations of stars changed the universe. "We want to understand what the properties of those first stars were and what were the elements they produced," said Chiti.

But no one has yet managed to directly see these first-generation stars, if any remain in the universe. Instead, Chiti and his colleagues look for stars that formed from the ashes of that first generation.

It's hard work, because even the second generation of stars is now incredibly ancient and rare. Most stars in the universe, including our own sun, are the result of tens to thousands of generations, building up more and more heavy elements each time. "Maybe fewer than 1 in 100,000 stars in the Milky Way is one of these second-gen stars," he said. "You really are fishing needles out of haystacks."

But it's worth it to get snapshots of what the universe looked like back in time. "In their outer layers, these stars preserve the elements near where they formed," he explained. "If you can find a very old star and get its chemical composition, you can understand what the chemical composition of the universe was like where that star formed, billions of years ago."

An intriguing oddity

For this study, Chiti and his colleagues aimed their telescopes at an unusual target: the stars that make up the Large Magellanic Cloud.

The Large Magellanic Cloud is a bright swath of stars visible to the naked eye in the Southern Hemisphere. We now think it was once a separate galaxy that was captured by the Milky Way's gravity just a few billion years ago. This makes it particularly interesting because its oldest stars were formed outside the Milky Way -- giving astronomers a chance to learn about whether conditions in the early universe all looked the same, or were different in other places.

The scientists searched for evidence of these particularly ancient stars in the Large Magellanic Cloud and catalogued ten of them, first with the European Space Agency's Gaia satellite and then with the Magellan Telescope in Chile.

One of these stars immediately jumped out as an oddity. It had much, much less of the heavier elements in it than any other star yet seen in the Large Magellanic Cloud. This means it was probably formed in the wake of the first generation of stars -- so it had not yet built up heavier elements over the course of repeated star births and deaths.

Mapping out its elements, the scientists were surprised to see that it had a lot less carbon than iron compared to what we see in Milky Way stars.

"That was very intriguing, and it suggests that perhaps carbon enhancement of the earliest generation, as we see in the Milky Way, was not universal," Chiti said. "We'll have to do further studies, but it suggests there are differences from place to place.

"I think we're filling out the picture of what the early element enrichment process looked like in different environments," he said.

Their findings also corroborated other studies that have suggested that the Large Magellanic Cloud made much fewer stars early on compared to the Milky Way.

Read more at Science Daily

Icy impacts: Planetary scientists use physics and images of impact craters to gauge the thickness of ice on Europa

Sometimes planetary physics is like being in a snowball fight. Most people, if handed an already-formed snowball, can use their experience and the feel of the ball to guess what kind of snow it is comprised of: packable and fluffy, or wet and icy.

Using nearly the same principles, planetary scientists have been able to study the structure of Europa, Jupiter's icy moon.

Europa is a rocky moon, home to saltwater oceans twice the volume of Earth's, encased in a shell of ice.

Scientists have long thought that Europa may be one of the best places in our solar system to look for nonterrestrial life.

The likelihood and nature of that life, though, heavily depend on the thickness of its icy shell, something astronomers have not yet been able to ascertain.

A team of planetary science experts including Brandon Johnson, an associate professor, and Shigeru Wakita, a research scientist, in the Department of Earth, Atmospheric, and Planetary Sciences in Purdue University's College of Science, announced in a new paper published in Science Advances [ES1] that Europa's ice shell is at least 20 kilometers thick.

To reach their conclusion, the scientists studied large craters on Europa, running a variety of models to determine what combination of physical characteristics could have created such a surface structure.

"This is the first work that has been done on this large crater on Europa," Wakita said.

"Previous estimates showed a very thin ice layer over a thick ocean. But our research showed that there needs to be a thick layer -- so thick that convection in the ice, which has previously been debated, is likely."

Using data and images from the spacecraft Galileo, which studied Europa in 1998, Johnson analyzed the impact craters to decode truths about Europa's structure.

An expert in planetary physics and colossal collisions, Johnson has studied almost every major planetary body in the solar system.

Scientists have long debated the thickness of Europa's ice shell; no one has visited to measure it directly, so scientists are creatively using the evidence at hand: the craters on Europa's icy surface.

"Impact cratering is the most ubiquitous surface process shaping planetary bodies," Johnson said.

"Craters are found on almost every solid body we've ever seen. They are a major driver of change in planetary bodies. When an impact crater forms, it is essentially probing the subsurface structure of a planetary body. By understanding the sizes and shapes of craters on Europa and reproducing their formation with numerical simulations, we're able to infer information about how thick its ice shell is."

Europa is a frozen world, but the ice shelters a rocky core.

The icy surface, though, is not stagnant. Plate tectonics and convection currents in the oceans and the ice itself refresh the surface fairly frequently.

This means the surface itself is only 50 million to 100 million years old -- which sounds old to short-lived organisms like humans, but is young as far as geological periods go.

That smooth, young surface means that craters are clearly defined, easier to analyze and not very deep.

Their impacts tell scientists more about the icy shell of the moon and the water ocean below, rather than conveying much information about its rocky heart.

Read more at Science Daily

The first Neolithic boats in the Mediterranean

More than 7,000 years ago, people navigated the Mediterranean Sea using technologically sophisticated boats, according to a study published March 20, 2024 in the open-access journal PLOS ONE by Juan F. Gibaja of the Spanish National Research Council, Barcelona and colleagues.

Many of the most important civilizations in Europe originated on the shores of the Mediterranean Sea.

During the Neolithic, communities clearly traveled and traded across the water, as evidenced by watercraft in the archeological record and the presence of settlements on coasts and islands.

In this study, Gibaja and colleagues provide new insights into the history of seafaring technology through analysis of canoes at the Neolithic lakeshore village of La Marmotta, near Rome, Italy.

Excavation at this site has recovered five canoes built from hollowed-out trees (dugout canoes) dating between 5700-5100BC.

Analysis of these boats reveals that they are built from four different types of wood, unusual among similar sites, and that they include advanced construction techniques such as transverse reinforcements.

One canoe is also associated with three T-shaped wooden objects, each with a series of holes that were likely used to fasten ropes tied to sails or other nautical elements.

These features, along with previous reconstruction experiments, indicate these were seaworthy vessels, a conclusion supported by the presence at the site of stone tools linked to nearby islands.

The authors describe these canoes as exceptional examples of prehistoric boats whose construction required a detailed understanding of structural design and wood properties in addition to well-organized specialized labor.

Similarities between these canoes and more recent nautical technologies support the idea that many major advances in sailing were made during the early Neolithic.

The authors suggest there may be more boats preserved near La Marmotta, a potential avenue for future research.

Read more at Science Daily

Toba supereruption unveils new insights into early human migration

Modern humans dispersed from Africa multiple times, but the event that led to global expansion occurred less than 100,000 years ago. Some researchers hypothesize that dispersals were restricted to "green corridors" formed during humid intervals when food was abundant and human populations expanded in lockstep with their environments. But a new study in Nature, including ASU researchers Curtis Marean, Christopher Campisano, and Jayde Hirniak, suggests that humans also may have dispersed during arid intervals along "blue highways" created by seasonal rivers. Researchers also found evidence of cooking and stone tools that represent the oldest evidence of archery.

Working in the Horn of Africa, researchers have uncovered evidence showing how early modern humans survived in the wake of the eruption of Toba, one of the largest supervolcanoes in history, some 74,000 years ago. The behavioral flexibility of these people not only helped them live through the supereruption but may have facilitated the later dispersal of modern humans out of Africa and across the rest of the world.

"This study confirms the results from Pinnacle Point in South Africa -- the eruption of Toba may have changed the environment in Africa, but people adapted and survived that eruption-caused environmental change," said Marean, research scientist with the Institute of Human Origins and Foundation Professor with the School of Human Evolution and Social Change.

The team investigated the Shinfa-Metema 1 site in the lowlands of present-day northwestern Ethiopia along the Shinfa River, a tributary of the Blue Nile River.

The supereruption occurred during the middle of the time when the site was occupied and is documented by tiny glass shards whose chemistry matches that of Toba.

Pinpoint timing through cryptotephra

"One of the ground-breaking implications of this study," said Marean, "is that with the new cryptotephra methods developed for our prior study in South Africa, and now applied here to Ethiopia, we can correlate sites across Africa, and perhaps the world, at a resolution of several weeks of time."

Cryptotephra are signature volcanic glass shards that can range from 80-20 microns in size, which is smaller than the diameter of a human hair. To extract these microscopic shards from archaeological sediment requires patience and great attention to detail.

"Searching for cryptotephra at these archaeological sites is like looking for a needle in a haystack, but not knowing if there is even a needle. However, having the ability to correlate sites 5,000 miles apart, and potentially further, to within weeks instead of thousands of years makes it all worth it," said Christopher Campisano, research scientist with the Institute of Human Origins and professor with the School of Human Evolution and Social Change.

"This study, once again," said Campisano, "highlights the importance of the University of Nevada-Las Vegas/Arizona State University team pushing the limits for successfully analyzing extremely low abundance cryptotephra to date and correlate archaeological sites across Africa."

The methods for identifying low abundance cryptotephra at Pinnacle Point were first developed at University of Nevada Las Vegas led by the late Gene Smith and Racheal Johnsen and now carried on at Arizona State University's Sediment and TEphra Preparation (STEP) Lab.

School of Human Evolution and Social Change graduate student Jayde Hirniak led ASU's effort to create its own cryptotephra lab -- the STEP Lab -- working with Campisano and building on methods developed at UNLV. Hirniak also collaborated with cryptotephra labs in the United Kingdom that work with sediment samples preserving hundreds or thousands of glass shards. Now Hirniak's primary expertise is in tephrochronology, which involves the use of volcanic ash to link archaeological and paleoenvironmental records and place them on the same timeline, which was her contribution to this research.

"Our lab at ASU was built to process extremely low abundance cryptotephra horizons (<10 shards per gram) using a highly specialized technique. There are only a few labs in the world with these capabilities," said Hirniak.

Migrations along "blue highways"

Based on isotope geochemistry of the teeth of fossil mammals and ostrich eggshells, they concluded that the site was occupied by humans during a time with long dry seasons on a par with some of the most seasonally arid habitats in East Africa today. Additional findings suggest that when river flows stopped during dry periods, people adapted by hunting animals that came to the remaining waterholes to drink. As waterholes continued to shrink, it became easier to capture fish without any special equipment, and diets shifted more heavily to fish.

Its climatic effects appear to have produced a longer dry season, causing people in the area to rely even more on fish. The shrinking of the waterholes may also have pushed humans to migrate outward in search of more food.

"As people depleted food in and around a given dry season waterhole, they were likely forced to move to new waterholes," said John Kappelman, a UT anthropology and earth and planetary sciences professor and lead author of the study. "Seasonal rivers thus functioned as 'pumps' that siphoned populations out along the channels from one waterhole to another, potentially driving the most recent out-of-Africa dispersal.

The humans who lived at Shinfa-Metema 1 are unlikely to have been members of the group that left Africa. However, the behavioral flexibility that helped them adapt to challenging climatic conditions such as the Toba supereruption was probably a key trait of Middle Stone Age humans that allowed our species to ultimately disperse from Africa and expand across the globe.

The people living in the Shinfa-Metema 1 site hunted a variety of terrestrial animals, from antelope to monkey, as attested to by cut marks on the bones, and apparently cooked their meals as shown by evidence of controlled fire at the site. The most distinctive stone tools are small, symmetrical triangular points. Analyses show that the points are most likely arrowheads that, at 74,000 years in age, represent the oldest evidence of archery.

Read more at Science Daily

Ultrablack coating could make next-gen telescopes even better

Sometimes, seeing clearly requires complete black. For astronomy and precision optics, coating devices in black paint can cut down on stray light, enhancing images and boosting performance. For the most advanced telescopes and optical systems, every little bit matters, so their manufacturers seek out the blackest blacks to coat them.

In the Journal of Vacuum Science & Technology A, by AIP Publishing, researchers from the University of Shanghai for Science and Technology and the Chinese Academy of Sciences developed an ultrablack thin-film coating for aerospace-grade magnesium alloys.

Their coating absorbs 99.3% of light while being durable enough to survive in harsh conditions.

For telescopes operating in the vacuum of space, or optical equipment in extreme environments, existing coatings are often insufficient.

"Existing black coatings like vertically aligned carbon nanotubes or black silicon are limited by fragility," said author Yunzhen Cao.

"It is also difficult for many other coating methods to apply coatings inside a tube or on other complicated structures. This is important for their application in optical devices as they often have significant curvature or intricate shapes."

To solve these problems, the researchers turned to atomic layer deposition (ALD). With this vacuum-based manufacturing technique, the target is placed in a vacuum chamber and sequentially exposed to specific types of gas, which adhere to the object's surface in thin layers.

"One big advantage of the ALD method lies in its excellent step-coverage ability, which means we can obtain uniform film coverage on very complex surfaces, such as cylinders, pillars, and trenches," said Cao.

To make their ultrablack coating, the team used alternating layers of aluminum-doped titanium carbide (TiAlC) and silicon nitride (SiO2). The two materials work together to prevent nearly all light from reflecting off the coated surface.

"TiAlC acted as an absorbing layer, and SiO2 was employed to create an anti-reflection structure," said Cao.

"As a result, nearly all of the incident light is trapped in the multilayer film, achieving efficient light absorption."

In tests, the team found an average absorption of 99.3% across a wide range of light wavelengths, from violet light at 400 nanometers all the way to near infrared at 1,000 nanometers.

Using a special barrier layer, they even applied their coating to magnesium alloys, which are often used in aerospace applications but are easily corroded.

"What's more, the film shows superb stability in adverse environments, and is tough enough to withstand friction, heat, damp conditions, and extreme temperature changes," said Cao.

The authors hope their coating will be used to enhance space telescopes and optical hardware operating in the most extreme conditions and are working to further improve its performance.

Read more at Science Daily

Cacao plants' defense against toxic cadmium unveiled

Researchers from the University Grenoble Alpes (UGA), France, together with the ESRF, the European Synchrotron located in Grenoble, France, used ESRF's bright X-rays to unveil how cacao trees protect themselves from toxic metal cadmium. This knowledge is relevant as new EU regulations restrict cadmium concentration in chocolate. Their results are published in Environmental and Experimental Botany.

Cadmium often accumulates in food, but it is a highly toxic metal, which can be harmful in humans if chronically exposed to it, according to the Food and Agricultural Organization.

The EU has imposed limits to the cadmium maximal concentration in foodstuffs such as rice, wheat, potatoes and more recently chocolate.

Whilst there have been studies on how cadmium is transferred from soil to the edible part of stable crops, there is hardly any research on cadmium in cacao cultivars.

"Understanding how cadmium builds up in cacao trees is paramount to subsequently find strategies to mitigate the accumulation of this metal in the final product," explains Geraldine Sarret, researcher at the University Grenoble Alpes (UGA) and co-corresponding author of the publication.

The UGA scientists travelled to the International Cocoa Genebank in Trinidad and Tobago, which hosts a field cacao collection with approximately 2400 cacao genotypes, to collect their samples in collaboration with the Cocoa Research Centre.

Then they came to the ESRF, the European Synchrotron, located in Grenoble, France, to investigate a particular cacao cultivar/variety that absorbs more cadmium than others do. Using synchrotron techniques -nano X-ray fluorescence on ESRF beamline ID16B and X-ray absorption on ID21-, they delved into the micro and nanoscale composition of the different parts of the plant.

"Thanks to the ESRF, we could map of the presence of cadmium and other elements in an unprecedented resolution, so we could see the big picture but also going to the smallest detail," says Hester Blommaert, PhD student at UGA and co-corresponding author of the publication.

"The concentration of cadmium in the different parts of the plant is very low, so much so that we couldn't have done this research before EBS," says Hiram Castillo-Michel, researcher at the ID21 beamline at the ESRF.

"In the near future, we will see an increasing number of studies on similar food safety topics at ID21, where our recently installed new microscope will offer enhanced resolution and detection limits," he adds.

The results yield a surprise: "We found that part of the cadmium is stored in calcium oxalate crystals in roots and branches of the cacao plant, which was unexpected," explains Blommaert.

In particular, the crystals were most abundant in the branches.

Interestingly, whilst crystals were present in the leaves, they did not seem to help in detoxifying cadmium in this part of the plant.

"We believe that the calcium oxalate crystals are a mechanism of detoxification of the plant against the metal," she adds.

In addition, they also discovered that cadmium combines with sulphur in certain cells in the roots.

This mechanism is well known in roots of cereals, where cadmium is retained in the vacuoles and bound to thiol-containing molecules.

In the case of cacao, this mechanism is less pronounced, and more cadmium is transferred to aerial parts.

Overall, the strategy developed by cacao plants to manage cadmium is different from cereals, in terms of root to shoot transfer, storage compartments and storage forms.

Read more at Science Daily

Kallistatin contributes to the beneficial metabolic effects of weight loss

After weight loss, people with overweight and obesity express more of the protein Kallistatin* in subcutaneous white adipose tissue. This was demonstrated by researchers from the DZD in a recent study. In addition, Kallistatin improves metabolism and could open up new therapeutic options for people with obesity and type 2 diabetes in future. The results have now been published in Molecular Metabolism.

An increasing number of people are developing type 2 diabetes and obesity.

These are highly complex and multifaceted diseases. In order to treat them sustainably, new approaches to therapy are needed.

Clinical studies on humans have shown that heavily overweight individuals produce less Kallistatin.

Kallistatin is a protein that has various effects in the body.

Among other things, it is involved in counteracting inflammation and healing wounds.

The role that Kallistatin plays in glucose metabolism and its potential suitability as a therapeutic target are currently being investigated by researchers from the German Center for Diabetes Research (DZD), the Institute for Diabetes Research and Metabolic Diseases (IDM) of Helmholtz Munich at the Eberhard-Karls-University of Tübingen, and the Department of Diabetology, Endocrinology and Nephrology at the University Hospital Tübingen.

Kallistatin Expression Increases After Weight Loss

To this end, they measured Kallistatin expression in subcutaneous white adipose tissue in 47 individuals with overweight to obesity before and after weight loss.

The result: Kallistatin expression increases after weight loss.

Kallistatin Improves Hepatic Insulin Sensitivity

Additionally, the researchers examined the effect of the protein in an animal model.

In the process, they observed that human Kallistatin improves hepatic insulin sensitivity in diet-induced obese mice.

Read more at Science Daily

Overeating and starving both damage the liver: Cavefish provide new insight into fatty liver disease

Fatty liver, which can lead to liver damage and disease, can occur from both overeating and starvation. Now, new research shows how naturally starvation-resistant cavefish, unlike other animals, are able to protect their liver and remain healthy. The findings have implications for understanding and potentially addressing liver conditions in humans.

Researchers from the Stowers Institute for Medical Research in collaboration with Universite Libre de Bruxelles in Belgium and Iowa State University compared cavefish to other animals more susceptible to starvation, and identified a gene responsible for the development of starvation-induced fatty liver.

The study, published in Life Science Alliance on March 11, 2024, led by co-first authors Ansa Cobham, Ph.D., in the lab of Associate Investigator Nicolas Rohner, Ph.D., and Macarena Pozo-Morales, Ph.D., in the lab of Assistant Professor Sumeet Pal Singh, Ph.D., also showed that this evolutionarily conserved gene can be targeted by an existing drug candidate to protect against liver damage.

"This same approach can be applied to what we see in overconsumption," Rohner said.

"In Western societies where, often, too many calories and not enough exercise is a problem, this new understanding may lead to prevention or potential treatment of fatty liver disease."

"We have discovered for the first time an organism -- cavefish -- that can avoid fatty liver under starvation conditions," said Cobham.

"Fatty liver can result in complications like liver cirrhosis and liver failure. This study helps us understand more about the biology underlying these diseases in humans."

Cavefish are cousins of the Mexican tetra river fish that flooded into underground caves over 100,000 years ago.

The researchers show that in the absence of food, cavefish at early developmental stages not only survive much longer than their river fish counterparts, but also do not accumulate liver fat.

"This was the first time we clearly showed that the mechanism for this resistance is accomplished by not accumulating excess fat in the liver," said Rohner.

The accumulation of fat in liver cells leads to organ damage and atrophy or wasting away.

The researchers compared gene expression levels between cavefish, river fish, zebrafish, and even fruit flies, identifying a gene that is activated during prolonged periods of starvation in all but cavefish.

"Expression levels of this gene are reduced in cavefish, which is a good indicator that if we are able to target this gene in humans, we may be able to treat or manage human metabolic diseases such as Type 2 diabetes and obesity," said Cobham.

The team's findings indicate that the starvation-induced gene not only regulates fatty liver disease, but its mechanism has also been conserved from fruit flies to fish to humans, or approximately 400 million years of animal evolution.

Inhibiting this gene's protein in zebrafish and river fish larvae and deleting the gene in fruit flies resulted in less liver fat and larger livers indicating this protects the liver from damage and atrophy.

Read more at Science Daily

Tanks of the Triassic: New crocodile ancestor identified

Dinosaurs get all the glory. But aetosaurs, a heavily armored cousin of modern crocodiles, ruled the world before dinosaurs did. These tanks of the Triassic came in a variety of shapes and sizes before going extinct around 200 million years ago. Today, their fossils are found on every continent except Antarctica and Australia.

Scientists use the bony plates that make up aetosaur armor to identify different species and usually don't have many fossil skeletons to work with. But a new study led by researchers at The University of Texas at Austin centers on an aetosaur suit of armor that has most of its major parts intact.

The suit -- called a carapace -- is about 70% complete and covers each major region of the body.

"We have elements from the back of the neck and shoulder region all the way to the tip of the tail," said William Reyes, a doctoral student at the UT Jackson School of Geosciences who led the research. "Usually, you find very limited material."

The research was published in The Anatomical Record.

Reyes and his collaborators used the armor to identify the specimen as a new aetosaur species -- which they named Garzapelta muelleri. The name "Garza" recognizes Garza County in northwest Texas, where the aetosaur was found, and "Pelta" is Latin for shield, a nod to aetosaurs' heavily fortified body. The species name "muelleri" honors the paleontologist who originally discovered it, Bill Mueller.

Garzapelta lived about 215 million years ago and resembled a modern American crocodile -- but with much more armor.

"Take a crocodile from modern day, and turn it into an armadillo," said Reyes.

The bony plates that covered Garzapelta and other aetosaurs are called osteoderms. They were embedded directly in the skin and formed a suit of armor by fitting together like a mosaic. In addition to having a body covered in bony plates, Garzapelta's sides were flanked by curved spikes that would have offered another layer of protection from predators. Although crocodiles today are carnivores, scientists think that aetosaurs were primarily omnivorous.

The spikes on Garzapelta are very similar to those found in another aetosaur species, but surprisingly, researchers found that the two species are only distantly related. The similarities, they discovered, are an example of convergent evolution, the independent evolution of similar traits in different species. The development of flight in insects, birds, mammals and now-extinct pterosaurs is a classic example of this phenomenon.

According to Reyes, an array of unique features on Garzapelta's plates clearly marked it as a new species. They range from how the plates fit together to unique bumps and ridges on the bones. However, figuring out where Garzapelta fit into the larger aetosaur family tree was more of challenge. Depending on which portion of the armor the researchers emphasized in their analysis, Garzapelta would end up in very different places. Armor that ran down its back resembled armor from one species, while its midsection spikes resembled armor from another.

Once the researchers determined that the spikes evolved independently, they were able to work out where Garzapelta fit best among other aetosaur species. Nevertheless, Reyes said the research shows how convergent evolution can complicate things.

"Convergence of the osteoderms across distantly related aetosaurs has been noted before, but the carapace of Garzapelta muelleri is the best example of it and shows to what extent it can happen and the problems it causes in our phylogenetic analyses," Reyes said.

Garzapelta is part of the Texas Tech University fossil collections. It spent most of the past 30 years on a shelf before Reyes encountered it during a visit. Bill Parker, an aetosaur expert and park paleontologist at Petrified Forest National Park who was not part of the research, said that university and museum collections are a critical part of making this type of research possible.

"These specimens weren't just dug in the field yesterday," he said. "They've been sitting in the museum for decades and it just takes someone like Will to come along and finally decide to study them and make them come to life."

In addition to different species having different armor, it's possible that an animal's age or sex could also affect armor appearance. Reyes is currently exploring these questions by studying aetosaur fossils in the Jackson School's collection, most of which were found during the 1940s as part of excavations done by the Works Progress Administration.

Read more at Science Daily

Meteorology: Weak polar vortex makes weather more predictable

Events in the stratosphere are making long-range weather in Northern Europe easier to forecast, researchers at LMU have discovered.

Weather is a chaotic system and predicting weather conditions several weeks in advance poses considerable challenges.

The accuracy of such long-range forecasts remains generally quite low.

Accordingly, even moderate improvements can prove valuable for various sectors.

For instance, farmers rely on these forecasts to determine optimal sowing and harvesting times, energy providers use them to anticipate fluctuations in renewable energy production, and public health officials use them to prepare for outbreaks of diseases such as malaria or dengue fever, which are correlated with specific weather conditions.

Researchers at LMU are now investigating a phenomenon that has its origin in the stratosphere, the layer of our atmosphere situated 15 to 50 kilometers above our heads.

"Previous work has shown that during Northern winter the state of the circulation in the polar stratosphere may provide useful information for improved long-range forecasts, especially for weather over the North Atlantic and Eurasia," explains Thomas Birner, Professor of Theoretical Meteorology at LMU.

In particular, when the polar vortex (a band of strong eastward circumpolar flow at stratospheric levels) strongly weakens or breaks down, the North Atlantic jetstream tends to shift southward and the likelihood of cold spells over Eurasia increases.

Such vortex breakdowns are relatively rare events that only happen approximately every other winter.

But its time has come round again: "One such event is currently unfolding with corresponding expected impacts on Eurasian weather in the coming weeks."

And now for the weather: cold, but less chaotic

In a study published recently in the journal Communications Earth & Environment, LMU meteorologists highlight an additional aspect of stratospheric influence on long-range weather forecasts: Weak polar vortex states, such as the one currently prevailing, are typically followed by reduced uncertainty of 3-5 week forecasts over Northern Europe.

The authors found that ensembles of forecasts show a reduced range of possible weather conditions by about 25%. Such ensembles are made up of a large number of individual forecasts, which typically diverge at longer forecasting periods.

After weak polar vortex events there is less spread among these forecasts over Northern Europe, making the weather more predictable.

"We attribute this reduced forecast uncertainty to the southward shift of the North Atlantic jetstream," says Jonas Spaeth, doctoral student at LMU's Meteorological Institute and lead author of the new study.

The associated southward shift of the tracks of winter storms, which are the main source of forecast uncertainty during this season, causes less storm activity and thereby reduced forecast uncertainty over Northern Europe.

Conversely, forecast uncertainty increases over Southern Europe.

Read more at Science Daily

Two artificial intelligences talk to each other

Performing a new task based solely on verbal or written instructions, and then describing it to others so that they can reproduce it, is a cornerstone of human communication that still resists artificial intelligence (AI). A team from the University of Geneva (UNIGE) has succeeded in modelling an artificial neural network capable of this cognitive prowess. After learning and performing a series of basic tasks, this AI was able to provide a linguistic description of them to a ''sister'' AI, which in turn performed them. These promising results, especially for robotics, are published in Nature Neuroscience.

Performing a new task without prior training, on the sole basis of verbal or written instructions, is a unique human ability.

What's more, once we have learned the task, we are able to describe it so that another person can reproduce it. This dual capacity distinguishes us from other species which, to learn a new task, need numerous trials accompanied by positive or negative reinforcement signals, without being able to communicate it to their congeners.

A sub-field of artificial intelligence (AI) -- Natural language processing -- seeks to recreate this human faculty, with machines that understand and respond to vocal or textual data.

This technique is based on artificial neural networks, inspired by our biological neurons and by the way they transmit electrical signals to each other in the brain.

However, the neural calculations that would make it possible to achieve the cognitive feat described above are still poorly understood.

''Currently, conversational agents using AI are capable of integrating linguistic information to produce text or an image.

But, as far as we know, they are not yet capable of translating a verbal or written instruction into a sensorimotor action, and even less explaining it to another artificial intelligence so that it can reproduce it,'' explains Alexandre Pouget, full professor in the Department of Basic Neurosciences at the UNIGE Faculty of Medicine.

A model brain

The researcher and his team have succeeded in developing an artificial neuronal model with this dual capacity, albeit with prior training.

''We started with an existing model of artificial neurons, S-Bert, which has 300 million neurons and is pre-trained to understand language.

We 'connected' it to another, simpler network of a few thousand neurons,'' explains Reidar Riveland, a PhD student in the Department of Basic Neurosciences at the UNIGE Faculty of Medicine, and first author of the study.

In the first stage of the experiment, the neuroscientists trained this network to simulate Wernicke's area, the part of our brain that enables us to perceive and interpret language.

In the second stage, the network was trained to reproduce Broca's area, which, under the influence of Wernicke's area, is responsible for producing and articulating words.

The entire process was carried out on conventional laptop computers.

Written instructions in English were then transmitted to the AI.

For example: pointing to the location -- left or right -- where a stimulus is perceived; responding in the opposite direction of a stimulus; or, more complex, between two visual stimuli with a slight difference in contrast, showing the brighter one.

The scientists then evaluated the results of the model, which simulated the intention of moving, or in this case pointing.

''Once these tasks had been learned, the network was able to describe them to a second network -- a copy of the first -- so that it could reproduce them.

To our knowledge, this is the first time that two AIs have been able to talk to each other in a purely linguistic way,'' says Alexandre Pouget, who led the research.

Read more at Science Daily

Backyard insect inspires invisibility devices, next gen tech

Leafhoppers, a common backyard insect, secrete and coat themselves in tiny mysterious particles that could provide both the inspiration and the instructions for next-generation technology, according to a new study led by Penn State researchers. In a first, the team precisely replicated the complex geometry of these particles, called brochosomes, and elucidated a better understanding of how they absorb both visible and ultraviolet light.

This could allow the development of bioinspired optical materials with possible applications ranging from invisible cloaking devices to coatings to more efficiently harvest solar energy, said Tak-Sing Wong, professor of mechanical engineering and biomedical engineering. Wong led the study, which was published today (March 18) in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

The unique, tiny particles have an unusual soccer ball-like geometry with cavities, and their exact purpose for the insects has been something of a mystery to scientists since the 1950s. In 2017, Wong led the Penn State research team that was the first to create a basic, synthetic version of brochosomes in an effort to better understand their function.

"This discovery could be very useful for technological innovation," said Lin Wang, postdoctoral scholar in mechanical engineering and the lead author of the study. "With a new strategy to regulate light reflection on a surface, we might be able to hide the thermal signatures of humans or machines. Perhaps someday people could develop a thermal invisibility cloak based on the tricks used by leafhoppers. Our work shows how understanding nature can help us develop modern technologies."

Wang went on to explain that even though scientists have known about brochosome particles for three-quarters of a century, making them in a lab has been a challenge due to the complexity of the particle's geometry.

"It has been unclear why the leafhoppers produce particles with such complex structures," Wang said, "We managed to make these brochosomes using a high-tech 3D-printing method in the lab. We found that these lab-made particles can reduce light reflection by up to 94%. This is a big discovery because it's the first time we've seen nature do something like this, where it controls light in such a specific way using hollow particles."

Theories on why leafhoppers coat themselves with a brochosome armor have ranged from keeping them free of contaminants and water to a superhero-like invisibility cloak. However, a new understanding of their geometry raises a strong possibility that its main purpose could be the cloak to avoid predators, according to Tak-Sing Wong, professor of mechanical engineering and biomedical engineering and corresponding author of the study.

The researchers have found that the size of the holes in the brochosome that give it a hollow, soccer ball-like appearance is extremely important. The size is consistent across leafhopper species, no matter the size of the insect's body. The brochosomes are roughly 600 nanometers in diameter -- about half the size of a single bacterium -- and the brochosome pores are around 200 nanometers.

"That makes us ask a question," Wong said. "Why this consistency? What is the secret of having brochosomes of about 600 nanometers with about 200-nanometer pores? Does that serve some purpose?"

The researchers found the unique design of brochosomes serves a dual purpose -- absorbing ultraviolet (UV) light, which reduces visibility to predators with UV vision, such as birds and reptiles, and scattering visible light, creating an anti-reflective shield against potential threats. The size of the holes is perfect for absorbing light at the ultraviolet frequency.

This potentially could lead to a variety of applications for humans using synthetic brochosomes, such as more efficient solar energy harvesting systems, coatings that protect pharmaceuticals from light-induced damage, advanced sunscreens for better skin protection against sun damage and even cloaking devices, researchers said. To test this, the team first had to make synthetic brochosomes, a major challenge in and of itself.

In their 2017 study, the researchers mimicked some features of brochosomes, particularly the dimples and their distribution, using synthetic materials. This allowed them to begin understanding the optical properties. However, they were only able to make something that looked like brochosomes, not an exact replica.

"This is the first time we are able to make the exact geometry of the natural brochosome," Wong said, explaining that the researchers were able to create scaled synthetic replicas of the brochosome structures by using advanced 3D-printing technology.

They printed a scaled-up version that was 20,000 nanometers in size, or roughly one-fifth the diameter of a human hair. The researchers precisely replicated the shape and morphology, as well as the number and placement of pores using 3D printing, to produce still-small faux brochosomes that were large enough to characterize optically.

They used a Micro-Fourier transform infrared (FTIR) spectrometer to examine how the brochosomes interacted with infrared light of different wavelengths, helping the researchers understand how the structures manipulate the light.

Next, the researchers said they plan to improve the synthetic brochosome fabrication to enable production at a scale closer to the size of natural brochosomes. They will also explore additional applications for synthetic brochosomes, such as information encryption, where brochosome-like structures could be used as part of an encryption system where data is only visible under certain light wavelengths.

Wang noted that their brochosome work demonstrates the value of a biomimetic research approach, where scientists looks to nature for inspiration.

"Nature has been a good teacher for scientists to develop novel advanced materials," Wang said. "In this study, we have just focused on one insect species, but there are many more amazing insects out there that are waiting for material scientists to study, and they may be able to help us solve various engineering problems. They are not just bugs; they are inspirations."

Read more at Science Daily

Protein fragments ID two new 'extremophile' microbes--and may help find alien life

Perfectly adapted microorganisms live in extreme environments from deep-sea trenches to mountaintops. Learning more about how these extremophiles survive in hostile conditions could inform scientists about life on Earth and potential life on other planets. In ACS' Journal of Proteome Research, researchers detail a method for more accurate extremophile identification based on protein fragments instead of genetic material. The study identified two new hardy bacteria from high-altitude lakes in Chile -- an environment like early Mars.

Even though humans tend to avoid settling in extremely hot, cold or high-altitude areas, some microorganisms have adapted to live in such harsh locations.

These extremophile microbes are of interest to astrobiologists who are searching for life on other planets.

Researchers currently use individual gene sequencing to identify Earth-bound microbes, based on their DNA.

However, current methods can't distinguish closely related species of extremophiles.

So, Ralf Moeller and colleagues investigated whether they could identify an extremophile by using its protein signature rather than a gene sequence.

The researchers started their demonstration with water samples from five high-altitude Andean lakes more than 2.3 miles above sea level in the Chilean Altiplano.

(For reference, Denver is about one mile above sea level.) From the samples, the researchers cultivated 66 microbes and then determined which of two methods better identified the microorganisms:

• Traditional gene sequencing compared the nucleotides of the 16s rRNA gene (a typical gene for sequence-based microbe analysis) from each sample to a database for identification.
• The newer "proteotyping" technique analyzed protein fragments known as peptides to produce peptide signatures, which the team used to identify microorganisms from proteome databases.

With these methods, the researchers identified 63 of the 66 microorganisms that were cultivated from the high-altitude lake samples.

For the three microorganisms that gene sequencing failed to identify because their genetic information wasn't in the available database, proteotyping identified two potentially new types of extremophile bacteria.

These results suggest proteotyping could be a more complete solution for identifying extremophile microorganisms from small biological samples.

The team says protein profiling could someday help us search for and identify extraterrestrial life and better explore the biodiversity on our own planet.

Read more at Science Daily

Oregon State researchers take deep dive into how much water is stored in snow

A heavy snowpack is fun for skiers and sledders, and it also acts like an open-air storage tank that melts away to provide water for drinking, irrigation and other purposes during dry months.

But exactly how much water is held in snowpacks, and for how long?

That information, critical to water managers around the globe, has taken on new clarity thanks to a new, more holistic calculation technique developed by researchers in the Oregon State University College of Engineering.

"Water managers tend to consider a portfolio of infrastructure options -- surface water reservoirs, groundwater recharge programs, etc. -- to match supply to demand," OSU's David Hill said. "Increased understanding of how much water is in snow should allow them to make long-term planning decisions for how to adjust that portfolio."

The study by Hill, a professor of civil engineering, and doctoral student Christina Aragon looked at nearly four decades of snowpack data. Through their new metric, which they call snow water storage, they identified a 22% drop in how much water is held annually in the mountain snowpacks of the lower 48 states.

"Unlike other widely used metrics that capture snow variables at a single point in time, like maximum snow water equivalent, or describe snow characteristics in terms of time, such as length of snow season, snow water storage is applicable at numerous time and space scales," Hill said. "It's really just a cumulative sum, not a maximum value; it's like adding up the number of miles you drive in a given year, rather than just thinking about the 500 you did on one day for your road trip."

In addition to introducing a better tool for gauging how much water is in snowpacks over periods of time, the findings are important because of what the new metric revealed about mountain snowpacks, which play an outsized role in the nation's water storage.

Hill and Aragon note that of all the water stored in the form of snow in the lower 48, 72% of it is in the mountains, though mountains cover just 16% of the total area.

"There are many ways to describe or quantify our snow resources, but some of the traditional measures, such as the April 1st snowpack, increasingly do not tell the full story," Hill said. "We present a new way of describing snow's water storage ability that adds deeper understanding and has more applicability in cases where our snowfall is increasingly intermittent or, regrettably, turning to rain."

The researchers' work, presented in a paper published in Hydrology and Earth System Sciences, builds on a commonly used measurement known as snow water equivalent; as its name implies, it's how much water is left in a container after the snow that was placed in it melts.

"By considering the amount of water held in the snowpack and the amount of time the water is stored as snow, we are able to quantify water storage in different types of snowpacks," Aragon said. "This includes persistent snowpacks, like we typically have at high elevations in the mountains; transient snowpacks, which are typically found at lower elevations; and snowpacks that are transitioning from persistent to transient due to climate warming."

Aragon adds that because the snow water storage metric can be applied to multiple types of snowpacks, it may become increasingly valuable for monitoring and predicting water resources "amidst a future of increased climate variability."

Hill points out that the past several years in the lower 48 have seen a "feast or famine cycle of extremes when it has come to the where and the when of our snow and rain." And in general snowpacks have considerably declined over the past 10 to 20 years.

"That particularly matters in places like Oregon, where 15% of the state's total annual precipitation falls as snow, and our snowpack functions like a reservoir," he said. "It holds back winter precipitation and slowly releases it in spring and early summer. This is useful because, at those times, our rainfall has tapered off for the year, but demand for water is on the rise."

As the climate warms and snowpacks become more and more variable -- the winter of 2023-24 is a good example, Hill said -- a metric like the new one developed at OSU helps to more objectively quantify the reservoir storage aspect of the globe's snowpacks.

From local to regional scales, he notes, municipal and agricultural users of water need to balance demand with supply, and snow storage dramatically influences the timing of the supply side.

"As we move forward, and as we have moved from the past to the present, the relatively good news is that annual precipitation amounts tend to not change that dramatically," he said. "However, changing temperatures greatly influence snow storage and therefore the timing of water availability."

Read more at Science Daily

Sustainable plastics from agricultural waste

In our rapidly industrialized world, the quest for sustainable materials has never been more urgent. Plastics, ubiquitous in daily life, pose significant environmental challenges, primarily due to their fossil fuel origins and problematic disposal.

Now, a study led by Jeremy Luterbacher's team at EPFL unveils a pioneering approach to producing high-performance plastics from renewable resources.

The research, published in Nature Sustainability, introduces a novel method for creating polyamides -- a class of plastics known for their strength and durability, the most famous of which are nylons -- using a sugar core derived from agricultural waste.

The new method leverages a renewable resource, and also achieves this transformation efficiently and with minimal environmental impact.

"Typical, fossil-based plastics need aromatic groups to give rigidity to their plastics -- this gives them performance properties like hardness, strength and high temperature resistance," says Luterbacher.

"Here, we get similar results but use a sugar structure, which is ubiquitous in nature and generally completely non-toxic, to provide rigidity and performance properties."

Lorenz Manker, the study's lead-author, and his colleagues developed a catalyst-free process to convert dimethyl glyoxylate xylose, a stabilized carbohydrate made directly from biomass such as wood or corn cobs, into high-quality polyamides.

The process achieves an impressive atom efficiency of 97%, meaning almost all the starting material is used in the final product, which drastically reduces waste.

The bio-based polyamides exhibit properties that can compete with their fossil counterparts, offering a promising alternative for various applications.

What's more, the materials demonstrated significant resilience through multiple cycles of mechanical recycling, maintaining their integrity and performance, which is a crucial factor for managing the lifecycle of sustainable materials.

The potential applications for these innovative polyamides are vast, ranging from automotive parts to consumer goods, all with a significantly reduced carbon footprint.

The team's techno-economic analysis and life-cycle assessment suggest these materials could be competitively priced against traditional polyamides including nylons (e.g. nylon 66), with a global warming potential reduction of up to 75%.

Read more at Science Daily