Right on schedule: Physicists use modeling to forecast a black hole's feeding patterns with precision

The dramatic dimming of a light source ~ 860 million light-years away from Earth confirms the accuracy of a detailed model developed by a team of astrophysicists, including Syracuse University Professor Eric Coughlin.

Powerful telescopes like NASA's Hubble, James Webb, and Chandra X-ray Observatory provide scientists a window into deep space to probe the physics of black holes. While one might wonder how you can "see" a black hole, which famously absorbs all light, this is made possible by tidal disruption events (TDEs) -- where a star is destroyed by a supermassive black hole and can fuel a "luminous accretion flare." With luminosities thousands of billions of times brighter than the Sun, accretion events enable astrophysicists to study supermassive black holes (SMBHs) at cosmological distances.

TDEs occur when a star is violently ripped apart by a black hole's immense gravitational field. As the star is shredded, its remnants are transformed into a stream of debris that rains back down onto the black hole to form a very hot, very bright disk of material swirling around the black hole, called an accretion disc. Scientists can study these to make direct observations of TDEs, and compare those to theoretical models to relate observations to physical properties of disrupted stars and their disrupting black holes.

A team of physicists from Syracuse University, MIT and the Space Telescope Science Institute used detailed modeling to predict the brightening and dimming of AT2018fyk, which is a repeating partial TDE, meaning the high-density core of the star survived the gravitational interaction with the SMBH, allowing it to orbit the black hole and be shredded more than once. The model predicted that AT2018fyk would "dim" in August 2023, a forecast which was confirmed when the source went dark last summer, providing evidence that their model delivers a new way to probe the physics of black holes. Their results were published in The Astrophysical Journal Letters.

A High Energy Source

Thanks to incredibly detailed extragalactic surveys, scientists are monitoring more coming and going light sources than ever before. Surveys pan entire hemispheres in search of sudden brightening or dimming of sources, which tells researchers that something has changed. Unlike the telescope in your living room that can only focus visible light, telescopes such as Chandra can detect light sources in what's referred to as the X-ray spectrum emitted from material that is millions of degrees in temperature.

Visible light and X-rays are both forms of electromagnetic radiation, but X-rays have shorter wavelengths and more energy. Similar to the way in which your stove becomes "red hot" after you turn it on, the gas comprising a disc "glows" at different temperatures, with the hottest material closest to the black hole. However, instead of radiating its energy at optical wavelengths visible to the eye, the hottest gas in an accretion disc emits in the X-ray spectrum. These are the same X-rays used by doctors to image your bones and that can pass through soft tissue, and because of this relative transparency, the detectors used by NASA X-ray telescopes are specifically designed to detect this high-energy radiation.'

A Repeat Performance

In January 2023, a team of physicists, including Eric Coughlin, a professor at Syracuse University's Department of Physics, Dheeraj R. "DJ" Pasham, a research scientist at MIT, and Thomas Wevers, a Fellow at the Space Telescope Science Institute, published a paper in The Astrophysical Journal Letters that proposed a detailed model for a repeating partial TDE. Their results were the first to map a star's surprising return orbit about a supermassive black hole -- revealing new information about one of the cosmos' most extreme environments.

The team based their study on a TDE known as AT2018fyk (AT stands for "Astrophysical Transient"), where a star was proposed to be captured by a SMBH through an exchange process known as "Hills capture." Originally part of a binary system (two stars that orbit one another under their mutual gravitational attraction), one of the stars was hypothesized to have been captured by the gravitational field of the black hole and the other (non-captured) star was ejected from the center of the galaxy at speeds comparable to ~ 1000 km/s.

Once bound to the SMBH, the star powering the emission from AT2018fyk has been repeatedly stripped of its outer envelope each time it passes through its point of closest approach with the black hole. The stripped outer layers of the star form the bright accretion disk, which researchers can study using X-Ray and Ultraviolet /Optical telescopes that observe light from distant galaxies.

While TDEs are usually "once-and-done" because the extreme gravitational field of the SMBH destroys the star, meaning that the SMBH fades back into darkness following the accretion flare, AT2018fyk offered the unique opportunity to probe a repeating partial TDE.

The research team has used a trio of telescopes to make the initial and follow-up detections: Swift and Chandra, both operated by NASA, and XMM-Newton, which is a European mission. First observed in 2018, AT2018fyk is ~ 870 million light years away, meaning that because of the time it takes light to travel, it happened in "real time" ~ 870 million years ago.

The team used detailed modeling to forecast that the light source would abruptly disappear around August 2023 and brighten again when the freshly stripped material accretes onto the black hole in 2025.

Model Validation

Confirming the accuracy of their model, the team reported an X-ray drop in flux over a span of two months, starting on August 14, 2023. This sudden change can be interpreted as the second emission shutoff.

"The observed emission shutoff shows that our model and assumptions are viable, and suggests that we are really seeing a star being slowly devoured by a distant and very massive black hole," says Coughlin. "In our paper last year, we used constraints from the initial outburst, dimming and rebrightening to predict that AT2018fyk should display a sudden and rapid dimming in August of 2023, if the star survived the second encounter that fueled the second brightening."

The fact that the system displayed this predicted shutoff therefore implies several distinctions about the star and the black hole:

• the star survived its second encounter with the black hole;
• the rate of return of stripped debris to the black hole is tightly coupled to the brightness of AT2018fyk;
• and the orbital period of the star about the black hole is ~ 1300 days, or about 3.5 years.

The second cutoff implies that another rebrightening should happen between May and August of 2025, and if the star survived the second encounter, a third shutoff is predicted to occur between January and July of 2027.

As for whether we can count on seeing a rebrightening in 2025, Coughlin says the detection of a second cutoff implies that the star has had more mass freshly stripped, which should return to the black hole to produce a third brightening.

"The only uncertainty is in the peak of the emission," he says. "The second re-brightened peak was considerably dimmer than the first, and it is, unfortunately, possible that the third outburst will be dimmer still. This is the only thing that would limit the detectability of this third outburst."

Coughlin notes that this model signifies an exciting new way to study the incredibly rare occurrences of repeating partial TDEs, which are believed to take place once every million years in a given galaxy. To date, he says scientists have encountered only four to five systems that display this behavior.

Read more at Science Daily

Rethinking the dodo

Researchers are setting out to challenge our misconceptions about the Dodo, one of the most well-known but poorly understood species of bird.

In a paper published today [16 August 2024] in the Zoological Journal of the Linnean Society researchers from the University of Southampton, Natural History Museum (NHM) and Oxford University Museum of Natural History have undertaken the most comprehensive review of the taxonomy of the Dodo and its closest relative, the Rodriguez Island Solitaire.

They've painstakingly gone through 400 years' worth of scientific literature and visited collections around the UK to ensure this iconic species, embodying humanity's destructive potential, is correctly classified.

"The Dodo was the first living thing that was recorded as being present and then disappeared," says Dr Neil Gostling from the University of Southampton, supervising author of the paper. "Before this, it hadn't been thought possible for human beings to influence God's creation in such a way.

"This was a time before the scientific principles and systems we rely on to label and classify a species were in place. Both the Dodo and the Solitaire were gone before we had a chance to understand what we were looking at."

Correcting the record

Much of what was written about the Dodo and the Solitaire was based on accounts from Dutch sailors, representations by artists, and incomplete remains.

The lack of a definitive reference point (type specimen) or convention to label species (zoological nomenclature) led to a series of misidentifications in the centuries following their extinction. New species such as the Nazarene Dodo, the White Dodo, and the White Solitaire were named, but the paper confirms that none of these creatures existed. Still, these erroneous 'pebbles' sent ripples through the waters of zoological literature.

"By the 18th and early 19th centuries, the Dodo and the Solitaire were considered to be mythological beasts," says Dr Mark Young, lead author of the paper from the University of Southampton. "It was the hard work of Victorian-era scientists who finally proved that the Dodo and the Solitaire were not mythological but were giant ground doves."

"Unfortunately, no one could agree how many species there had been," continues Dr Young. "Throughout most of the 19th and 20th centuries, researchers thought there were three different species, although some people thought there had been four or even five different species."

To unpick this confusion, researchers went through all the literature on the Dodo and Rodriguez Solitaire encompassing hundreds of accounts dating back to 1598 and visited specimens around the UK, including the world's only surviving soft tissue from the Dodo, in the Oxford Museum.

"More has been written about the Dodo than any other bird, yet virtually nothing is known about it in life," says Dr Julian Hume, an avian palaeontologist at the Natural History Museum and coauthor of the paper.

"Based on centuries of nomenclatural confusion, and some 400 years after its extinction, the Dodo and Solitaire, continue to prompt heated debate. We've gone from where the first statements were made, seen how these have developed, and identified various rabbit holes to correct the record, as best we can."

Through this work, researchers were able to confirm that both birds were members of the columbid (pigeon and dove) family.

"Understanding its wider relationships with other pigeons is of taxonomic importance, but from the perspective of conservation, the loss of the dodo and the solitaire a few decades later means a unique branch of the pigeon family tree was lost," says Dr Gostling. "There are no other birds alive today like these two species of giant ground dove."

Challenging our misconceptions

The researchers believe the popular idea of the Dodo as a fat, slow animal, predestined for extinction is flawed.

"Even four centuries later, we have so much to learn about these remarkable birds," says Dr Young. "Was the Dodo really the dumb, slow animal we've been brought up to believe it was? The few written accounts of live Dodos say it was a fast-moving animal that loved the forest."

Dr Gostling adds: "Evidence from bone specimens suggests that the Dodo's tendon which closed its toes was exceptionally powerful, analogous to climbing and running birds alive today. The dodo was almost certainly a very active, very fast animal.

"These creatures were perfectly adapted to their environment, but the islands they lived on lacked mammalian predators. So, when humans arrived, bringing rats, cats, and pigs, the Dodo and the Solitaire never stood a chance.

"Dodos held an integral place in their ecosystems. If we understand them, we might be able to support ecosystem recovery in Mauritius, perhaps starting to undo the damage that began with the arrival of humans nearly half a millennium ago."

Learning 'valuable lessons'

The study marks the beginning of a wider project to understand the biology of these iconic animals.

"The mystery of the Dodo bird is about to be cracked wide open," says Dr Markus Heller, Professor of Biomechanics at the University of Southampton, a coauthor on the paper.

"We have assembled a fantastic team of scientists to uncover the true nature of this famous extinct bird. But we are not just looking back in time -- our research could help save today's endangered birds too."

Dr Heller explains: "Using cutting-edge computer technology, we are piecing together how the Dodo lived and moved. This isn't just about satisfying our curiosity. By understanding how birds evolved in the past, we are learning valuable lessons that could help protect bird species today."

"It's like solving a 300-year-old puzzle, and the solution might just help us prevent more birds from going the way of the Dodo."

The project will include work with palaeoartist Karen Fawcett, who has created a detailed, life-size model of the Dodo to bring the words on the pages of books and journal articles to life. She says: "This work has been the merging of science and art to achieve accuracy and realism so that these creatures come back from the dead, real and tangible for people to touch and see."

Read more at Science Daily

New brain-computer interface allows man with ALS to 'speak' again

A new brain-computer interface (BCI) developed at UC Davis Health translates brain signals into speech with up to 97% accuracy -- the most accurate system of its kind.

The researchers implanted sensors in the brain of a man with severely impaired speech due to amyotrophic lateral sclerosis (ALS). The man was able to communicate his intended speech within minutes of activating the system.

A study about this work was published today in the New England Journal of Medicine.

ALS, also known as Lou Gehrig's disease, affects the nerve cells that control movement throughout the body. The disease leads to a gradual loss of the ability to stand, walk and use one's hands. It can also cause a person to lose control of the muscles used to speak, leading to a loss of understandable speech.

The new technology is being developed to restore communication for people who can't speak due to paralysis or neurological conditions like ALS. It can interpret brain signals when the user tries to speak and turns them into text that is 'spoken' aloud by the computer.

"Our BCI technology helped a man with paralysis to communicate with friends, families and caregivers," said UC Davis neurosurgeon David Brandman. "Our paper demonstrates the most accurate speech neuroprosthesis (device) ever reported."

Brandman is the co-principal investigator and co-senior author of this study. He is an assistant professor in the UC Davis Department of Neurological Surgery and co-director of the UC Davis Neuroprosthetics Lab.

The new BCI breaks the communication barrier

When someone tries to speak, the new BCI device transforms their brain activity into text on a computer screen. The computer can then read the text out loud.

To develop the system, the team enrolled Casey Harrell, a 45-year-old man with ALS, in the BrainGate clinical trial. At the time of his enrollment, Harrell had weakness in his arms and legs (tetraparesis). His speech was very hard to understand (dysarthria) and required others to help interpret for him.

In July 2023, Brandman implanted the investigational BCI device. He placed four microelectrode arrays into the left precentral gyrus, a brain region responsible for coordinating speech. The arrays are designed to record the brain activity from 256 cortical electrodes.

"We're really detecting their attempt to move their muscles and talk," explained neuroscientist Sergey Stavisky. Stavisky is an assistant professor in the Department of Neurological Surgery. He is the co-director of the UC Davis Neuroprosthetics Lab and co-principal investigator of the study. "We are recording from the part of the brain that's trying to send these commands to the muscles. And we are basically listening into that, and we're translating those patterns of brain activity into a phoneme -- like a syllable or the unit of speech -- and then the words they're trying to say."

Faster training, better results

Despite recent advances in BCI technology, efforts to enable communication have been slow and prone to errors. This is because the machine-learning programs that interpreted brain signals required a large amount of time and data to perform.

"Previous speech BCI systems had frequent word errors. This made it difficult for the user to be understood consistently and was a barrier to communication," Brandman explained. "Our objective was to develop a system that empowered someone to be understood whenever they wanted to speak."

Harrell used the system in both prompted and spontaneous conversational settings. In both cases, speech decoding happened in real time, with continuous systemupdates to keep it working accurately.

The decoded words were shown on a screen. Amazingly, they were read aloud in a voice that sounded like Harrell's before he had ALS. The voice was composed using software trained with existing audio samples of his pre-ALS voice.

At the first speech data training session, the system took 30 minutes to achieve 99.6% word accuracy with a 50-word vocabulary.

"The first time we tried the system, he cried with joy as the words he was trying to say correctly appeared on-screen. We all did," Stavisky said.

In the second session, the size of the potential vocabulary increased to 125,000 words. With just an additional 1.4 hours of training data, the BCI achieved a 90.2% word accuracy with this greatly expanded vocabulary. After continued data collection, the BCI has maintained 97.5% accuracy.

"At this point, we can decode what Casey is trying to say correctly about 97% of the time, which is better than many commercially available smartphone applications that try to interpret a person's voice," Brandman said. "This technology is transformative because it provides hope for people who want to speak but can't. I hope that technology like this speech BCI will help future patients speak with their family and friends."

The study reports on 84 data collection sessions over 32 weeks. In total, Harrell used the speech BCI in self-paced conversations for over 248 hours to communicate in person and over video chat.

"Not being able to communicate is so frustrating and demoralizing. It is like you are trapped," Harrell said. "Something like this technology will help people back into life and society."

"It has been immensely rewarding to see Casey regain his ability to speak with his family and friends through this technology," said the study's lead author, Nicholas Card. Card is a postdoctoral scholar in the UC Davis Department of Neurological Surgery.

"Casey and our other BrainGate participants are truly extraordinary. They deserve tremendous credit for joining these early clinical trials. They do this not because they're hoping to gain any personal benefit, but to help us develop a system that will restore communication and mobility for other people with paralysis," said co-author and BrainGate trial sponsor-investigator Leigh Hochberg. Hochberg is a neurologist and neuroscientist at Massachusetts General Hospital, Brown University and the VA Providence Healthcare System.

Read more at Science Daily

Researchers unveil mysteries of ancient Earth

A team of researchers has made strides in understanding the formation of massif-type anorthosites, enigmatic rocks that only formed during the middle part of Earth's history. These plagioclase-rich igneous rock formations, which can cover areas as large as 42,000 square kilometers and host titanium ore deposits, have puzzled scientists for decades due to conflicting theories about their origins.

A new study published in Science Advances on Aug. 14 highlights the intricate connections between Earth's evolving mantle and crust and the tectonic forces that have shaped the planet throughout its history. It also provides new ways to explore when plate tectonics began, how subduction dynamics operated billions of years ago and the evolution of Earth's crust.

The research team, led by Rice's Duncan Keller and Cin-Ty Lee, studied massif-type anorthosites to test ideas about the magmas that formed them. The research focused on the Marcy and Morin anorthosites, classic examples from North America's Grenville orogen that are about 1.1 billion years old.

By analyzing the isotopes of boron, oxygen, neodymium and strontium in the rocks as well as conducting petrogenetic modeling, the researchers discovered that the magmas that formed these anorthosites were rich in melts derived from oceanic crust altered by seawater at low temperatures. They also found isotopic signatures corresponding to other subduction zone rocks such as abyssal serpentinite.

"Our research indicates that these giant anorthosites likely originated from the extensive melting of subducted oceanic crust beneath convergent continental margins," said Keller, the Clever Planets Postdoctoral Research Associate, Earth, Environmental and Planetary Sciences and the study's lead author. "Because the mantle was hotter in the past, this process directly connects the formation of massif-type anorthosites to Earth's thermal and tectonic evolution."

The study, which combines classical methods with the novel application of boron isotopic analysis to massif-type anorthosites, suggests that these rocks formed during very hot subduction that may have been prevalent billions of years ago.

Because massif-type anorthosites don't form on Earth today, the new evidence linking these rocks to very hot subduction on the early Earth opens new interdisciplinary approaches for understanding how these rocks chronicle the physical evolution of our planet.

"This research advances our understanding of ancient rock formations and sheds light on the broader implications for Earth's tectonic and thermal history," said Lee, the Harry Carothers Wiess Professor of Geology, professor of Earth, environmental and planetary sciences and study co-author.

Read more at Science Daily

Hailstone library to improve extreme weather forecasting

A University of Queensland library -- full of hailstones instead of books -- is helping researchers to better understand and predict damaging storms.

Dr Joshua Soderholm, an Honorary Senior Research Fellow from UQ's School of the Environment, and lead researcher PhD candidate Yuzhu Lin from Penn State in the US, have found storm modelling outcomes change significantly when using real hailstones.

Key points:

• Researchers are measuring and scanning samples for a global 'hailstone library'
• Storm simulations using 3-D modelling of real hailstones show it behaves differently than spherical hail shapes
• Data from the hail library could lead to more accurate storm forecasts

"People tend to think of a hailstone as a perfect sphere, like a golf ball or cricket ball," Dr Soderholm said.

"But hail can be all sorts of weird shapes, from oblong to a flat disc or have spikes coming out -- no two pieces of hail are the same.

"Conventional scientific modelling of hail assumes spherical hailstones, and we wanted to know if that changed when non-spherical, natural hail shapes are used."

Ms Lin said they found the differences were dramatic.

"Modelling of the more naturally shaped hail showed it took different pathways through the storm, experienced different growth and landed in different places," Ms Lin said.

"It also affected the speed and impact the hail had on the ground.

"This way of modelling had never been done before, so it's exciting science."

Dr Soderholm said building a 'hailstone library' was critical to further fine-tuning hailstorm simulations.

"This is effectively a dataset to represent the many and varied shapes of hailstones, to make weather modelling more accurate," he said.

"Our study used data from 217 hail samples, which were 3-D scanned and the sliced in half, to tell us more about how the hailstone formed.

"This data is now part of a global library, as we try and get a really clear picture of hailstone shape and structure."

Dr Soderholm said the research has significant potential.

"At the moment, the modelling is specifically for scientists studying storms, but the end game is to be able to predict in real-time how big hail will be, and where it will fall," he said.

"More accurate forecasts would of course warn the public so they can stay safe during hailstorms and mitigate damage.

"But it could also significantly benefit industries such as insurance, agriculture and solar farming which are all sensitive to hail."

Read more at Science Daily

Why do plants wiggle? New study provides answers

In a new study, physicists from the United States and Israel may have gotten to the bottom of a quirky behavior of growing plants -- and a mystery that intrigued Charles Darwin himself during the later decades of his life.

For many humans, plants might seem stationary and even a little dull. But green things actually move a lot. If you watch a timelapse video of a sunflower seedling poking up from the soil, for example, it doesn't just shoot straight up. Instead, as the sunflower grows, its crown spins in circles, twists into corkscrews and, in general, wiggles around -- albeit very slowly.

Now, researchers co-led by Orit Peleg at CU Boulder and Yasmine Meroz at Tel Aviv University have discovered one role for these chaotic movements, also known as "circumnutations." In greenhouse experiments and computer simulations, the group showed that sunflowers take advantage of circumnutations to search the environment around them for patches of sunlight.

"A lot of people don't really consider the motion of plants because, as humans, we're usually looking at plants at the wrong frame rate," said Peleg, a co-author of the study and an associate professor in the BioFrontiers Institute and Department of Computer Science.

The team published its findings Aug. 15 in the journal Physical Review X.

The findings could one day help farmers to come up with new strategies for growing an array of crops in more efficient arrangements.

"Our team does a lot of work on social interactions in insect swarms and other groups of animals," said Chantal Nguyen, lead author and a postdoctoral researcher at BioFrontiers.

"But this research is particularly exciting because we're seeing similar dynamics in plants. They're rooted to the ground."

Darwin's cucumbers

Nguyen added that plants don't usually shift around like animals but, instead, move by growing in different directions over time. This phenomenon enchanted Darwin long after he returned from his voyage on the HMS Beagle, according to historical accounts.

In the 1860s, Darwin, who was then suffering from a range of ailments that limited his own mobility, spent days observing plants at his home. He planted seeds from cucumbers and other species, then traced how their crowns moved around from day to day -- the resulting maps look wild and haphazard.

"I am getting very much amused by my tendrils -- it is just the sort of niggling work which suits me," he wrote a friend in 1863.

Amused or not, Darwin couldn't explain why some of his tendrils twisted.

It's a mystery that has also perplexed Meroz, a physicist by training. One 2017 study pointed her in the right direction. In it, scientists led by the University of Buenos Aires grew lines of sunflowers under cramped conditions. They discovered that the plants naturally and consistently arranged themselves into a zig-zag pattern, almost like the teeth of a zipper. The arrangement likely helps the plants maximize their access to sunlight as a group.

Meroz wondered if plant wiggles could be the engine that drives such patterns in plant growth.

"For climbing plants, it's obvious that it's about searching for supports to twine on," said Meroz, a professor of plant sciences and food security. "But for other plants, it's not clear why it's worth it."

Here comes the sun

To find out, she and her colleagues grew five, one-week-old sunflowers in rows. Then, like Darwin before them, they mapped out how the plants moved over the course of a week.

Next, Nguyen and Peleg developed a computer program to analyze the patterns behind the sunflower growth. The researchers could also use their computer simulations to see what would happen if the sunflowers moved more or less -- in other words, if they wiggled haphazardly or in a slow and steady pattern.

If the digital plants didn't wiggle at all, the group discovered, they would all wind up all leaning away from each other in a straight line. If they wiggled too much, in contrast, they would grow in a random pattern. If they moved with just the right amount of randomness, however, the sunflowers formed that tell-tale zig-zag, which, in real life plants, provides a lot of access to sunlight. Nguyen explained that plants seem to circumnutate to find where the best light is coming from, then grow in that direction.

"When you add a little bit of noise into the system, it allows the plant to explore its surroundings and settle into those configurations that allow each plant to find maximum light exposure," she said. "That happens to lead to this nice zig-zag pattern that we see."

In future experiments, the researchers will test out how sunflowers grow in more complicated arrangements. Meroz, for her part, is glad to see plants get some credit for the movers and shakers they really are.

Read more at Science Daily

Engineers design tiny batteries for powering cell-sized robots

A tiny battery designed by MIT engineers could enable the deployment of cell-sized, autonomous robots for drug delivery within in the human body, as well as other applications such as locating leaks in gas pipelines.

The new battery, which is 0.1 millimeters long and 0.002 millimeters thick -- roughly the thickness of a human hair -- can capture oxygen from air and use it to oxidize zinc, creating a current of up to 1 volt. That is enough to power a small circuit, sensor, or actuator, the researchers showed.

"We think this is going to be very enabling for robotics," says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the study. "We're building robotic functions onto the battery and starting to put these components together into devices."

Ge Zhang PhD '22 and Sungyun Yang, an MIT graduate student, are the lead author of the paper, which appears in Science Robotics.

Powered by batteries

For several years, Strano's lab has been working on tiny robots that can sense and respond to stimuli in their environment. One of the major challenges in developing such tiny robots is making sure that they have enough power.

Other researchers have shown that they can power microscale devices using solar power, but the limitation to that approach is that the robots must have a laser or another light source pointed at them at all times. Such devices are known as "marionettes" because they are controlled by an external power source. Putting a power source such as a battery inside these tiny devices could free them to roam much farther.

"The marionette systems don't really need a battery because they're getting all the energy they need from outside," Strano says. "But if you want a small robot to be able to get into spaces that you couldn't access otherwise, it needs to have a greater level of autonomy. A battery is essential for something that's not going to be tethered to the outside world."

To create robots that could become more autonomous, Strano's lab decided to use a type of battery known as a zinc-air battery. These batteries, which have a longer lifespan than many other types of batteries due to their high energy density, are often used in hearing aids.

The battery that they designed consists of a zinc electrode connected to a platinum electrode, embedded into a strip of a polymer called SU-8, which is commonly used for microelectronics. When these electrodes interact with oxygen molecules from the air, the zinc becomes oxidized and releases electrons that flow to the platinum electrode, creating a current.

In this study, the researchers showed that this battery could provide enough energy to power an actuator -- in this case, a robotic arm that can be raised and lowered. The battery could also power a memristor, an electrical component that can store memories of events by changing its electrical resistance, and a clock circuit, which allows robotic devices to keep track of time.

The battery also provides enough power to run two different types of sensors that change their electrical resistance when they encounter chemicals in the environment. One of the sensors is made from atomically thin molybdenum disulfide and the other from carbon nanotubes.

"We're making the basic building blocks in order to build up functions at the cellular level," Strano says.

Robotic swarms

In this study, the researchers used a wire to connect their battery to an external device, but in future work they plan to build robots in which the battery is incorporated into a device.

"This is going to form the core of a lot of our robotic efforts," Strano says. "You can build a robot around an energy source, sort of like you can build an electric car around the battery."

One of those efforts revolves around designing tiny robots that could be injected into the human body, where they could seek out a target site and then release a drug such as insulin. For use in the human body, the researchers envision that the devices would be made of biocompatible materials that would break apart once they were no longer needed.

The researchers are also working on increasing the voltage of the battery, which may enable additional applications.

Read more at Science Daily

Galaxies in dense environments tend to be larger, settling one cosmic question and raising others

For decades, scientists have known that some galaxies reside in dense environments with lots of other galaxies nearby. Others drift through the cosmos essentially alone, with few or no other galaxies in their corner of the universe.

A new study has found a major difference between galaxies in these divergent settings: Galaxies with more neighbors tend to be larger than their counterparts, which have a similar shape and mass, but reside in less dense environments. In a paper published Aug. 14 in the Astrophysical Journal, researchers at the University of Washington, Yale University, the Leibniz Institute for Astrophysics Potsdam in Germany and Waseda University in Japan report that galaxies found in denser regions of the universe are as much as 25% larger than isolated galaxies.

The research, which used a new machine-learning tool to analyze millions of galaxies, helps resolve a long-standing debate among astrophysicists over the relationship between a galaxy's size and its environment. The findings also raise new questions about how galaxies form and evolve over billions of years.

"Current theories of galaxy formation and evolution cannot adequately explain the finding that clustered galaxies are larger than their identical counterparts in less dense regions of the universe," said lead author Aritra Ghosh, a UW postdoctoral researcher in astronomy and an LSST-DA Catalyst Fellow with the UW's DiRAC Institute. "That's one of the most interesting things about astrophysics. Sometimes what the theories predict we should find and what a survey actually finds are not in agreement, and so we go back and try to modify existing theories to better explain the observations."

Past studies that looked into the relationship between galaxy size and environment came up with contradictory results. Some determined that galaxies in clusters were smaller than isolated galaxies. Others came to the opposite conclusion. The studies were generally much smaller in scope, based on observations of hundreds or thousands of galaxies.

In this new study, Ghosh and his colleagues utilized a survey of millions of galaxies conducted using the Subaru Telescope in Hawaii. This endeavor, known as the Hyper Suprime-Cam Subaru Strategic Program, took high-quality images of each galaxy. The team selected approximately 3 million galaxies with the highest-quality data and used a machine learning algorithm to determine the size of each one. Next, the researchers essentially placed a circle -- one with a radius of 30 million light years -- around each galaxy. The circle represents the galaxy's immediate vicinity. They then asked a simple question: How many neighboring galaxies lie within that circle?

The answer showed a clear general trend: Galaxies with more neighbors were also on average larger.

There could be many reasons why. Perhaps densely clustered galaxies are simply larger when they first form, or are more likely to undergo efficient mergers with close neighbors. Perhaps dark matter -- that mysterious substance that makes up most of the matter in the universe, yet cannot be detected directly by any current means -- plays a role. After all, galaxies form within individual "halos" of dark matter and the gravitational pull from those halos plays a critical role in how galaxies evolve.

"Theoretical astrophysicists will have to perform more comprehensive studies using simulations to conclusively establish why galaxies with more neighbors tend to be larger," said Ghosh. "For now, the best we can say is that we're confident that this relationship between galaxy environment and galaxy size exists."

Utilizing an incredibly large dataset like the Hyper Suprime-Cam Subaru Strategic Program helped the team reach a clear conclusion. But that's only part of the story. The novel machine learning tool they used to help determine the size of each individual galaxy also accounted for inherent uncertainties in the measurements of galaxy size.

"One important lesson we had learned prior to this study is that settling this question doesn't just require surveying large numbers of galaxies," said Ghosh. "You also need careful statistical analysis. A part of that comes from machine learning tools that can accurately quantify the degree of uncertainty in our measurements of galaxy properties."

The machine learning tool that they used is called GaMPEN -- or Galaxy Morphology Posterior Estimation Network. As a doctoral student at Yale, Ghosh led development of GaMPEN, which was unveiled in papers published in 2022 and 2023 in the Astrophysical Journal. The tool is freely available online and could be adapted to analyze other large surveys, said Ghosh.

Though this new study focuses on galaxies, it also forecasts the types of research -- centered on complex analyses of incredibly large datasets -- that will soon take astronomy by storm. When a generation of new telescopes with powerful cameras, including the Vera C. Rubin Observatory in Chile, come online, they will collect massive amounts of data on the cosmos every night. In anticipation, scientists have been developing new tools like GaMPEN that can utilize these large datasets to answer pressing questions in astrophysics.

"Very soon, large datasets will be the norm in astronomy," said Ghosh. "This study is a perfect demonstration of what you can do with them -- when you have the right tools."

Read more at Science Daily

Climate reporting standards insufficient, must be expanded, say experts

A new paper from the Smith School of Enterprise and the Environment, University of Oxford concludes that current climate standards are not sufficiently incentivising the big picture innovations necessary to deliver net zero, and must be expanded to include a company's broader influence on climate action. The peer-reviewed research, published in Carbon Management, comes after a period of fierce public debate about climate standards and offers possible solutions for those seeking to improve both integrity and impact of corporate climate action.

Incentivising climate action and innovation in the corporate world is essential says co-author Dr Matilda Becker: "Of the 2000 largest companies, close to half still do not yet have a net zero target, while some are going further without reward. We need to incentivise companies' efforts beyond their boundaries."

The authors discuss actions that companies can take to accelerate the global transition to net zero across three spheres of influence: product power, purchasing power and political power, and propose an additional reporting track to capture their impact in these areas.

This track would demonstrate a company's wider contribution to global net zero, and examples could include lobbying for cleaner energy systems or signalling financial support for new net zero technologies.

To date, corporate climate standards have been created primarily to guide companies in setting targets (e.g. through the Science Based Targets initiative) and to help them track their own emissions resulting from their activities (e.g. using the Greenhouse Gas Protocol). While these standards have been essential for reducing the emissions of individual companies, say the authors, they fail to incentivise broader climate action and can even discourage it.

"It is essential that companies report and reduce emissions across their value chains," says co-author Claire Wigg, Head of Climate Performance Practice at the Exponential Roadmap Initiative.

"But it is also essential that they drive -- and are rewarded for driving -- systemic change via the products they produce, the purchases they make and the policies they lobby for or against."

Read more at Science Daily

Zebrafish use surprising strategy to regrow spinal cord

Zebrafish are members of a rarefied group of vertebrates capable of fully healing a severed spinal cord. A clear understanding of how this regeneration takes place could provide clues toward strategies for healing spinal cord injuries in people. Such injuries can be devastating, causing permanent loss of sensation and movement.

A new study from Washington University School of Medicine in St. Louis maps out a detailed atlas of all the cells involved -- and how they work together -- in regenerating the zebrafish spinal cord. In an unexpected finding, the researchers showed that survival and adaptability of the severed neurons themselves is required for full spinal cord regeneration. Surprisingly, the study showed that stem cells capable of forming new neurons -- and typically thought of as central to regeneration -- play a complementary role but don't lead the process.

The study is published Thursday, Aug. 15, in the journal Nature Communications.

Unlike humans' and other mammals' spinal cord injuries, in which damaged neurons always die, the damaged neurons of zebrafish dramatically alter their cellular functions in response to injury, first to survive and then to take on new and central roles in orchestrating the precise events that govern healing, the researchers found. Scientists knew that zebrafish neurons survive spinal cord injury, and this new study reveals how they do it.

"We found that most, if not all, aspects of neural repair that we're trying to achieve in people occur naturally in zebrafish," said senior author Mayssa Mokalled, PhD, an associate professor of developmental biology. "The surprising observation we made is that there are strong neuronal protection and repair mechanisms happening right after injury. We think these protective mechanisms allow neurons to survive the injury and then adopt a kind of spontaneous plasticity -- or flexibility in their functions -- that gives the fish time to regenerate new neurons to achieve full recovery. Our study has identified genetic targets that will help us promote this type of plasticity in the cells of people and other mammals."

By mapping out the evolving roles of various cell types involved in regeneration, Mokalled and her colleagues found that the flexibility of the surviving injured neurons and their capacity to immediately reprogram after injury lead the chain of events that are required for spinal cord regeneration. If these injury-surviving neurons are disabled, zebrafish do not regain their normal swim capacity, even though regenerative stem cells remain present.

When the long wiring of the spinal cord is crushed or severed in people and other mammals, it sets off a chain of toxicity events that kills the neurons and makes the spinal cord environment hostile against repair mechanisms. This neuronal toxicity could provide some explanation for the failure of attempts to harness stem cells to treat spinal cord injuries in people. Rather than focus on regeneration with stem cells, the new study suggests that any successful method to heal spinal cord injuries in people must start with saving the injured neurons from death.

"Neurons by themselves, without connections to other cells, do not survive," Mokalled said. "In zebrafish, we think severed neurons can overcome the stress of injury because their flexibility helps them establish new local connections immediately after injury. Our research suggests this is a temporary mechanism that buys time, protecting neurons from death and allowing the system to preserve neuronal circuitry while building and regenerating the main spinal cord."

There is some evidence that this capacity is present but dormant in mammalian neurons, so this may be a route to new therapies, according to the researchers.

"We are hopeful that identifying the genes that orchestrate this protective process in zebrafish -- versions of which also are present in the human genome -- will help us find ways to protect neurons in people from the waves of cell death that we see following spinal cord injuries," she said.

Read more at Science Daily

Cleaning up the aging brain: Scientists restore brain's trash disposal system

Alzheimer's, Parkinson's, and other neurological disorders can be seen as "dirty brain" diseases, where the brain struggles to clear out harmful waste. Aging is a key risk factor because, as we grow older, our brain's ability to remove toxic buildup slows down. However, new research in mice demonstrates that it's possible to reverse age-related effects and restore the brain's waste-clearing process.

"This research shows that restoring cervical lymph vessel function can substantially rescue the slower removal of waste from the brain associated with age," said Douglas Kelley, PhD, a professor of Mechanical Engineering in the University of Rochester Hajim School of Engineering and Applied Sciences. "Moreover, this was accomplished with a drug already being used clinically, offering a potential treatment strategy." Kelley is one of the lead authors of the study, which appears in the journal Nature Aging, along with Maiken Nedergaard, MD, DMSc, co-director the University's Center for Translational Neuromedicine.

First described by Nedergaard and her colleagues in 2012, the glymphatic system is the brain's unique waste removal process that uses cerebrospinal fluid (CSF) to wash away excess proteins generated by energy hungry neurons and other cells in the brain during normal activity. This discovery pointed the way for potential new approaches to treat diseases commonly associated with the accumulation of protein waste in the brain, such Alzheimer's (beta amyloid and tau) and Parkinson's (alpha-synuclein). In healthy and young brains, the glymphatic system does a good job of flushing away these toxic proteins, however, as we age, this system slows, setting the stage for these diseases.

A network of tiny pumps draws waste from the brain

Once laden with protein waste, CSF in the skull needs to make its way to the lymphatic system and ultimately the kidneys, where it is processed along with the body's other waste. The new research combines advanced imaging and particle tracking techniques to describe for the first time in detail the route via the cervical lymph vessels in the neck through which half of dirty CSF exits the brain.

In addition to measuring the flow of CSF, the researchers were able observe and record the pulsing of lymph vessels in the neck that helps draw CSF out of the brain. "Unlike the cardiovascular system which has one big pump, the heart, fluid in the lymphatic system is instead transported by a network of tiny pumps," said Kelley. These microscopic pumps, called lymphangions, have valves to prevent backflow and are strung together, one after another, to form lymph vessels.

The researchers found that as the mice aged, the frequency of contractions decreased, and the valves failed. As a result, the speed of dirty CSF flowing out of the brains of older mice was 63 percent slower compared to younger animals.

Known drug restarts flow of brain cleaning fluids

The team then set out to see if they could revive the lymphangions and identified a drug called prostaglandin F2α, a hormone-like compound commonly used medically to induce labor and known to aid smooth muscle contraction. The lymphangions are lined with smooth muscle cells, and when the researchers applied the drug to the cervical lymph vessels in older mice, the frequency of contractions and the flow of dirty CSF from the brain both increased, returning to a level of efficiency found in younger mice.

"These vessels are conveniently located near the surface of the skin, we know they are important, and we now know how to accelerate function," said Kelley. "One can see how this approach, perhaps combined with other interventions, could be the basis for future therapies for these diseases."

Read more at Science Daily

Rocks from Mars' Jezero Crater, which likely predate life on Earth, contain signs of water

In a new study appearing today in the journal AGU Advances, scientists at MIT and NASA report that seven rock samples collected along the "fan front" of Mars' Jezero Crater contain minerals that are typically formed in water. The findings suggest that the rocks were originally deposited by water, or may have formed in the presence of water.

The seven samples were collected by NASA's Perseverance rover in 2022 during its exploration of the crater's western slope, where some rocks were hypothesized to have formed in what is now a dried-up ancient lake. Members of the Perseverance science team, including MIT scientists, have studied the rover's images and chemical analyses of the samples, and confirmed that the rocks indeed contain signs of water, and that the crater was likely once a watery, habitable environment.

Whether the crater was actually inhabited is yet unknown. The team found that the presence of organic matter -- the starting material for life -- cannot be confirmed, at least based on the rover's measurements. But judging from the rocks' mineral content, scientists believe the samples are their best chance of finding signs of ancient Martian life once the rocks are returned to Earth for more detailed analysis.

"These rocks confirm the presence, at least temporarily, of habitable environments on Mars," says the study's lead author, Tanja Bosak, professor of geobiology in MIT's Department of Earth, Atmospheric, and Planetary Sciences (EAPS). "What we've found is that indeed there was a lot of water activity. For how long, we don't know, but certainly for long enough to create these big sedimentary deposits."

What's more, some of the collected samples may have originally been deposited in the ancient lake more than 3.5 billion years ago -- before even the first signs of life on Earth.

"These are the oldest rocks that may have been deposited by water, that we've ever laid hands or rover arms on," says co-author Benjamin Weiss, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT. "That's exciting, because it means these are the most promising rocks that may have preserved fossils, and signatures of life."

The study's MIT co-authors include postdoc Eva Scheller, and research scientist Elias Mansbach, along with members of the Perseverance science team.

At the front

The new rock samples were collected in 2022 as part of the rover's Fan Front Campaign -- an exploratory phase during which Perseverance traversed Jezero Crater's western slope, where a fan-like region contains sedimentary, layered rocks. Scientists suspect that this "fan front" is an ancient delta that was created by sediment that flowed with a river and settled into a now bone-dry lakebed. If life existed on Mars, scientists believe that it could be preserved in the layers of sediment along the fan front.

In the end, Perseverance collected seven samples from various locations along the fan front. The rover obtained each sample by drilling into the Martian bedrock and extracting a pencil-sized core, which it then sealed in a tube to one day be retrieved and returned to Earth for detailed analysis.

Prior to extracting the cores, the rover took images of the surrounding sediments at each of the seven locations. The science team then processed the imaging data to estimate a sediment's average grain size and mineral composition. This analysis showed that all seven collected samples likely contain signs of water, suggesting that they were initially deposited by water.

Specifically, Bosak and her colleagues found evidence of certain minerals in the sediments that are known to precipitate out of water.

"We found lots of minerals like carbonates, which are what make reefs on Earth," Bosak says. "And it's really an ideal material that can preserve fossils of microbial life."

Interestingly, the researchers also identified sulfates in some samples that were collected at the base of the fan front. Sulfates are minerals that form in very salty water -- another sign that water was present in the crater at one time -- though very salty water, Bosak notes, "is not necessarily the best thing for life." If the entire crater was once filled with very salty water, then it would be difficult for any form of life to thrive. But if only the bottom of the lake were briny, that could be an advantage, at least for preserving any signs of life that may have lived further up, in less salty layers, that eventually died and drifted down to the bottom.

"However salty it was, if there were any organics present, it's like pickling something in salt," Bosak says. "If there was life that fell into the salty layer, it would be very well-preserved."

Fuzzy fingerprints

But the team emphasizes that organic matter has not been confidently detected by the rover's instruments. Organic matter can be signs of life, but can also be produced by certain geological processes that have nothing to do with living matter. Perseverance's predecessor, the Curiosity rover, had detected organic matter throughout Mars' Gale Crater, which scientists suspect may have come from asteroids that made impact with Mars in the past.

And in a previous campaign, Perseverance detected what appeared to be organic molecules at multiple locations along Jezero Crater's floor. These observations were taken by the rover's Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument, which uses ultraviolet light to scan the Martian surface. If organics are present, they can glow, similar to material under a blacklight. The wavelengths at which the material glows act as a sort of fingerprint for the kind of organic molecules that are present.

In Perseverance's previous exploration of the crater floor, SHERLOC appeared to pick up signs of organic molecules throughout the region, and later, at some locations along the fan front. But a careful analysis, led by MIT's Eva Scheller, has found that while the particular wavelengths observed could be signs of organic matter, they could just as well be signatures of substances that have nothing to do with organic matter.

"It turns out that cerium metals incorporated in minerals actually produce very similar signals as the organic matter," Scheller says. "When investigated, the potential organic signals were strongly correlated with phosphate minerals, which always contain some cerium."

Scheller's work shows that the rover's measurements cannot be interpreted definitively as organic matter.

"This is not bad news," Bosak says. "It just tells us there is not very abundant organic matter. It's still possible that it's there. It's just below the rover's detection limit."

When the collected samples are finally sent back to Earth, Bosak says laboratory instruments will have more than enough sensitivity to detect any organic matter that might lie within.

Read more at Science Daily

Great Scott! Stonehenge's Altar Stone origins reveal advanced ancient Britain

New research led by Curtin University has revealed Stonehenge's monumental six-tonne Altar Stone, long believed to originate from Wales, actually hails from Scotland.

Furthermore, the findings point to the existence of unexpectedly advanced transport methods and societal organisation at the time of the stone's arrival at its current location in southern England about 5000 years ago.

Curtin researchers studied the age and chemistry of mineral grains within fragments of the Altar Stone, which is a 50cm thick sandstone block measuring 5 x 1 metres, that sits at the centre of Stonehenge's iconic stone circle in Wiltshire.

Lead author PhD student Anthony Clarke from the Timescales of Mineral Systems Group within Curtin's School of Earth and Planetary Sciences said analysis of the age and chemical composition of minerals within fragments of the Altar Stone matched it with rocks from northeast Scotland, while also clearly differentiating them from Welsh bedrock.

"Our analysis found specific mineral grains in the Altar Stone are mostly between 1000 to 2000 million years old, while other minerals are around 450 million years old," Mr Clarke said.

"This provides a distinct chemical fingerprint suggesting the stone came from rocks in the Orcadian Basin, Scotland, at least 750 kilometres away from Stonehenge.

"Given its Scottish origins, the findings raise fascinating questions, considering the technological constraints of the Neolithic era, as to how such a massive stone was transported over vast distances around 2600 BC.

"This discovery also holds personal significance for me. I grew up in the Mynydd Preseli, Wales, where some of Stonehenge's stones came from. I first visited Stonehenge when I was one year old and now at 25, I returned from Australia to help make this scientific discovery -- you could say I've come full circle at the stone circle."

Study co-author Professor Chris Kirkland, also from the Timescales of Mineral Systems Group at Curtin, said the findings had significant implications for understanding ancient communities, their connections, and their transportation methods.

"Our discovery of the Altar Stone's origins highlights a significant level of societal coordination during the Neolithic period and helps paint a fascinating picture of prehistoric Britain," Professor Kirkland said.

"Transporting such massive cargo overland from Scotland to southern England would have been extremely challenging, indicating a likely marine shipping route along the coast of Britain.

"This implies long-distance trade networks and a higher level of societal organisation than is widely understood to have existed during the Neolithic period in Britain."

Funded by an Australian Research Council Discovery Project, the research was performed in collaboration with Aberystwyth University, The University of Adelaide and University College London.

Co-author Professor Richard Bevins from Aberystwyth University said the findings overturned what had been thought for the past century.

"We have succeeded in working out, if you like, the age and chemical fingerprints of perhaps one of the most famous of stones in the world-renowned ancient monument," Professor Bevins said.

"While we can now say that this iconic rock is Scottish and not Welsh, the hunt will still very much be on to pin down where exactly in the north-east of Scotland the Altar Stone came from."

Co-author Dr Robert Ixer of the UCL Institute of Archaeology said the findings were genuinely shocking, but if plate tectonics and atomic physics were correct, then the Altar Stone is Scottish.

"The work prompts two important questions: why and exactly how was the Altar Stone transported from the very north of Scotland, a distance of more than 700 kilometres, to Stonehenge?"

Curtin Vice-Chancellor Professor Harlene Hayne said much of the research and analysis done by Mr Clarke and Professor Kirkland was undertaken at the University's John de Laeter Centre.

"This fascinating study is another example of the stellar work being undertaken by Curtin University's Timescales of Mineral Systems Group with the John de Laeter Centre, using state-of-the-art equipment in our GeoHistory Facility that supports important minerals research," Professor Hayne said.

"It offers specialist mass spectrometers which are used to examine the composition of materials such as rock-forming minerals, archaeological artefacts, meteorites, ceramics and even biological substances such as teeth, bones and shell.

"Ongoing investment is required to maintain cutting-edge facilities like this, which are crucial for attracting the world's best minds. In this case, we are delighted that our outstanding research reputation and facilities led PhD student Anthony Clarke to travel 15,000 kilometres from his home in Wales to study at Curtin and make this significant finding."

Mr Clarke said he chose Curtin for his PhD because it also offered the chance to work alongside renowned researchers, such as Professor Kirkland.

"Curtin has given us the freedom and independence to explore fascinating work, such as Stonehenge and access to the world's most advanced equipment and expert staff means I can complete all my work there," Mr Clarke said.

Read more at Science Daily

Significant link found between heme iron, found in red meat and other animal products, and type 2 diabetes risk

Higher intake of heme iron, the type found in red meat and other animal products -- as opposed to non-heme iron, found mostly in plant-based foods -- was associated with a higher risk of developing type 2 diabetes (T2D) in a new study led by researchers at Harvard T.H. Chan School of Public Health. While the link between heme iron and T2D has been reported previously, the study's findings more clearly establish and explain the link.

"Compared to prior studies that relied solely on epidemiological data, we integrated multiple layers of information, including epidemiological data, conventional metabolic biomarkers, and cutting-edge metabolomics," said lead author Fenglei Wang, research associate in the Department of Nutrition. "This allowed us to achieve a more comprehensive understanding of the association between iron intake and T2D risk, as well as potential metabolic pathways underlying this association."

The study will be published August 13 in Nature Metabolism.

The researchers assessed the link between iron and T2D using 36 years of dietary reports from 206,615 adults enrolled in the Nurses' Health Studies I and II and the Health Professionals Follow-up Study. They examined participants' intake of various forms of iron -- total, heme, non-heme, dietary (from foods), and supplemental (from supplements) -- and their T2D status, controlling for other health and lifestyle factors.

The researchers also analyzed the biological mechanisms underpinning heme iron's relationship to T2D among smaller subsets of the participants. They looked at 37,544 participants' plasma metabolic biomarkers, including those related to insulin levels, blood sugar, blood lipids, inflammation, and two biomarkers of iron metabolism. They then looked at 9,024 participants' metabolomic profiles -- plasma levels of small-molecule metabolites, which are substances derived from bodily processes such as breaking down food or chemicals.

The study found a significant association between higher heme iron intake and T2D risk. Participants in the highest intake group had a 26% higher risk of developing T2D than those in the lowest intake group. In addition, the researchers found that heme iron accounted for more than half of the T2D risk associated with unprocessed red meat and a moderate proportion of the risk for several T2D-related dietary patterns. In line with previous studies, the researchers found no significant associations between intakes of non-heme iron from diet or supplements and risk of T2D.

The study also found that higher heme iron intake was associated with blood metabolic biomarkers associated with T2D. A higher heme iron intake was associated with higher levels of biomarkers such as C-peptide, triglycerides, C-reactive protein, leptin, and markers of iron overload, as well as lower levels of beneficial biomarkers like HDL cholesterol and adiponectin.

The researchers also identified a dozen blood metabolites -- including L-valine, L-lysine, uric acid, and several lipid metabolites -- that may play a role in the link between heme iron intake and TD2 risk. These metabolites have been previously associated with risk of T2D.

On a population level, the study findings carry important implications for dietary guidelines and public health strategies to reduce rates of diabetes, according to the researchers. In particular, the findings raise concerns about the addition of heme to plant-based meat alternatives to enhance their meaty flavor and appearance. These products are gaining in popularity, but health effects warrant further investigation.

"This study underscores the importance of healthy dietary choices in diabetes prevention," said corresponding author Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology. "Reducing heme iron intake, particularly from red meat, and adopting a more plant-based diet can be effective strategies in lowering diabetes risk."

The researchers noted that the study had several limitations, including the potential for incomplete accounting for confounders and measurement errors in the epidemiological data. In addition, the findings -- based on a study population that was mostly white -- need to be replicated in other racial and ethnic groups.

Read more at Science Daily

New interpretation of runic inscription reveals pricing in Viking age

A new interpretation of the runic inscription on the Forsa Ring (Forsaringen in Swedish), provides fresh insights into the Viking Age monetary system and represents the oldest documented value record in Scandinavia. The inscription describes how the Vikings handled fines in a flexible and practical manner. This is highlighted in research from the Department of Economic History and International Relations at Stockholm University, recently published in the Scandinavian Economic History Review.

"The Forsaringen inscription "uksa … auk aura tua" was previously interpreted to mean that fines had to be paid with both an ox and two ore of silver. This would imply that the guilty party had to pay with two different types of goods, which would have been both impractical and time-consuming," says Rodney Edvinsson, Professor of Economic History at Stockholm University, who conducted the study.

The Forsa Ring is an iron ring from Hälsingland, dated to the 9th or 10th century. The runic inscription on the ring describes fines for a specific offense, where payment was to be made in the form of oxen and silver. The ring is believed to have been used as a door handle and is currently the oldest known preserved legal text in Scandinavia. By changing the translation of the word "auk" from the previous interpretation "and" to the new interpretation "also," the meaning changes so that fines could be paid either with an ox or with two ore of silver. An ore was equivalent to about 25 grams of silver.

"This indicates a much more flexible system, where both oxen and silver could be used as units of payment. If a person had easier access to oxen than to silver, they could pay their fines with an ox. Conversely, if someone had silver but no oxen, they could pay with two ore of silver," says Rodney Edvinsson.

The new interpretation shows that the Vikings had a system where both oxen and silver served as units of payment. This system allowed for multiple types of units of accounts to be used concurrently, reducing transaction complexity and making it easier for people to meet their financial obligations. The new interpretation also aligns better with how the system functioned later according to later regional laws and is, according to Rodney Edvinsson, significant for our understanding of both Scandinavian and European monetary history.

"As an economic historian, I particularly look for historical data to be economically logical, that is, to fit into other contemporary or historical economic systems. The valuation of an ox at two ore, or 50 grams of silver, in 10th-century Sweden resembles contemporary valuations in other parts of Europe, indicating a high degree of integration and exchange between different economies," says Rodney Edvinsson.

He has previously contributed to developing a historical consumer price index extending back to the 13th century, but this new interpretation provides insights into price levels even earlier in history.

"The price level during the Viking Age in silver was much lower than in the early 14th century and late 16th century, but approximately at the same level as in the late 15th century and the 12th century, when there was a silver shortage," says Rodney Edvinsson.

The study highlights the importance of using modern economic theories to interpret historical sources. By combining economic theory with archaeological and historical findings, new opportunities for interdisciplinary research and a deeper understanding of early economic systems are opened up.

What Did Things Cost During the Viking Age?

According to the new interpretation, an ox would cost 2 öre of silver, about 50 grams of silver, during the Viking Age. This corresponds to roughly 100,000 Swedish kronor today, if compared to the value of an hour's work. The Forsa Ring's fine amount was therefore quite high. One öre was likely equivalent to about nine Arabic dirhams, a currency that circulated in large quantities among the Vikings. A common price for a thrall was 12 öre of silver, or approximately 600,000 Swedish kronor today. The wergild for a free man, i.e., the fine paid to the family of the murdered to avoid blood revenge, was much higher, around 5 kilos of silver, which is about 10 million Swedish kronor today. The significant difference in value between a thrall and a free man reflects the power dynamics between free individuals and thralls in a slave society.

The relevant inscription of the Forsa Ring translated to modern English: One ox and [also/or] two öre of silver to the staff for the restoration of a sanctuary in a valid state for the first time; two oxen and [also/or] four öre of silver for the second time; but for the third time four oxen and eight öre of silver.

From Science Daily

Measuring Martian winds with sound

Mars has a notoriously inhospitable environment, with temperatures that fluctuate dramatically over the course of a Martian day and average minus 80 degrees Fahrenheit. Its surface is mostly covered in red dust, with terrain typified by craters, canyons, and volcanoes. And its atmosphere is extremely thin, comprising only about 1% of the density of Earth's.

Needless to say, measuring wind speeds on the red planet is challenging.

Martian landers have been able capture measurements -- some gauging the cooling rate of heated materials when winds blow over them, others using cameras to image "tell-tales" that blow in the wind.

Both anemometric methods have yielded valuable insight into the planet's climate and atmosphere.

But there's still room for improvement in the astronomical toolshed, especially as plans to send astronauts to Mars unfold in the coming years.

In JASA, published on behalf of the Acoustical Society of America by AIP Publishing, researchers from Canada and the U.S. demonstrated a novel sonic anemometric system featuring a pair of narrowband piezoelectric transducers to measure the travel time of sound pulses through Martian air.

The study accounted for variables including transducer diffraction effects and wind direction.

"By measuring sound travel time differences both forward and backward, we can accurately measure wind in three dimensions," said author Robert White.

"The two major advantages of this method are that it's fast and it works well at low speeds."

The researchers hope to be able to measure up to 100 wind speeds per second and at speeds as low as 1 cm/s, a remarkable contrast to previous methods that could register only about 1 wind speed per second and struggled to track speeds below 50 cm/s.

"By measuring quickly and accurately, we hope to be able to measure not only mean winds, but also turbulence and fluctuating winds," said White.

"This is important for understanding atmospheric variables that could be problematic for small vehicles such as the Ingenuity helicopter that flew on Mars recently."

The researchers characterized ultrasonic transducers and sensors over a wide range of temperatures and a narrow range of pressures in carbon dioxide, the primary atmospheric gas on Mars.

With their selections, they showed only nominal error rates would result from temperature and pressure changes.

Read more at Science Daily

New study unveils 16,000 years of climate history in the tropical Andes

A new study that explores ancient temperatures and rainfall patterns in the tropical Andes of South America has revealed how 16,000 years of climate history in this part of the world was driven by carbon dioxide levels and ocean currents from global climate events.

Led by Brown University researchers, the study marks the first high-resolution temperature record covering the past 16,000 years in the tropical Andes and could help scientists predict and mitigate future climate impacts in tropical regions of the planet. The work is described in the Proceedings of the National Academy of Science.

"Usually when we study climate change in the past, we emphasize the Northern Hemisphere or Southern Hemisphere because of the outsized role they play in affecting climates all over the globe," said Boyang Zhao, a scientist in Brown's Department of Earth, Environmental and Planetary Sciences and the study's first author. "One of the biggest questions we are getting at is what are the driving factors behind temperature history in this part of the tropics, so that we can begin to potentially apply that data and knowledge to other tropical regions."

Along with future implications, the new study provides a unique look at the way distinct and distant parts of the world influence temperature and weather elsewhere, emphasizing how regional climates are connected to global climate changes.

"Our evidence here suggests that temperatures in this region of the world are more influenced by the Southern Hemisphere -- so places like Antarctica," Zhao said.

The study focused on an analysis of sediment samples from Laguna Llaviucu, a lake located in Ecuador's Cajas National Park. The measurements from the sediment samples showed that temperature variations in the tropical Andes closely aligned with climate events that saw the planet's temperatures rise and fall during the past 16,000 years.

Overall, the evidence showed that the main driver in these temperature fluctuations was the concentration of CO2. Researchers saw evidence that the tropical Andean temperatures track with Antarctic temperatures, which are mainly controlled by carbon dioxide concentrations. The findings showed that about 17,000 to 14,000 years ago, tropical Andean temperatures rose when carbon dioxide increased and that the temperatures remained relatively stable about 12,000 years ago when carbon dioxide levels remained relatively stable.

Zhao said that the findings support previous research identifying carbon dioxide as a key driver of global temperature changes since the last Ice Age.

The study also highlighted the role of ocean currents that move warm water from the tropics to the North Atlantic. During a cooling period known as the Antarctic Cold Reversal 14,500 years ago, the northward current was strengthened, causing it to transport more heat northward and cool sea surface temperatures in the south. The researchers found that this cooling effect extended to the tropical Andes.

To reconstruct past climate conditions, the researchers analyzed lipid biomarkers and hydrogen isotopes collected in 2009 from Laguna Llaviucu by scientist Mark Bush from the Florida Institute of Technology. Lipid biomarkers are chemical compounds that provide clues about past temperatures and rainfall patterns. The high-resolution data, combined with accurate dating techniques, allowed the team to create a detailed timeline of climate changes over the past 16,000 years.

According to the researchers, this is the first time organic biomarkers have been used to put together a quantitative climate history for tropical South America. It is traditionally difficult to reconstruct temperatures from the tropics.

The study also points out a number of regional differences in temperature patterns, like how the tropical Andes and Southeast Asia cooled during certain historical periods while other regions like Africa did not.The research also shows how local factors may help to counteract the global effects of rising CO2 levels by looking at differences between past temperature models and what the sediment data show.

The researchers from Brown plan to continue to explore past temperature patterns in this part of the world that historically lacks complete climate records.

"Mountain environments are some of the most sensitive regions on Earth to climate change," said James Russell, a professor of Earth, environmental, and planetary sciences at Brown who oversaw the new research. "In fact, in the near future, high tropical mountains, such as the Andes, are predicted to experience a rate of warming second only to the Arctic, which is the fastest warming part of the planet."

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Researchers make breakthrough in understanding species abundance

When it comes to predicting the abundance of a species, body size appears to be a fundamental and repeatable predictor, with smaller organisms occurring in greater numbers than larger ones. The caveat, known as Bermann's Rule, is that in polar regions larger bodied organisms predominate. Other factors that influence species abundance include light availability, food availability, competition and predation.

New findings by a team of researchers in biological sciences at the U of A have now added a genetic component to our understanding of species abundance.

Genome size, the total amount of DNA contained within one copy of a single complete genome, can also be a strong predictor of species abundance. The paper examined diatoms, which are unicellular algae that play an important role in freshwater and marine food webs. They create long-chain fatty acids, like fish oil and other lipids, that serve as energy. The energy molecules that diatoms produce go up the food web from zooplankton to aquatic insects to fish to humans.

Diatoms also play a critical role in photosynthesis, the process by which carbon dioxide is converted to oxygen. It's estimated that 20-25 percent of Earth's oxygen comes from diatoms -- more than rainforests and land plants.

The key finding was that temperature and genome size, not body size, had the greatest influence on the maximum population growth rate of the diatoms. Yet body size still mattered in colder latitudes, conserving Bermann's Rule.

The paper, "Diatom abundance in the polar oceans is predicted by genome size," was published in PLoS Biology by a trio of authors from the Department of Biological Sciences: Wade Roberts, a postdoctoral researcher in the Alverson Lab; Adam Siepielski, an associate professor; and Andrew Alverson, professor and director of the Alverson Lab.

Roberts noted that the genome size of a diatom is critical to cell function and its ability to adapt to a changing environment.

"In phytoplankton, cell size is highly correlated to genome size," Roberts explained. "We've known that for a while. But we weren't sure if cell size was driving genome size or vice versa. We were able to directly test this through a path analysis to determine the directionality. We found that an increase in genome size led to increased cell size. So, we confirmed that size of the genome is driving cell size."

The genome size of diatoms can vary by 50-fold between species, but most of the difference in genetic material is made up of repeated DNA. DNA codes for the proteins that are the building blocks of life, but it's unclear how this repetitive DNA is utilized by the cell. It's estimated that only about 2 percent of the human genome codes for genes.

Overall, the paper's results advance understanding of species abundance by showing that a single emergent trait fundamental to all life, the size of the genome, can predict species abundance at a global scale.

"Larger organisms are more abundant in polar regions," Roberts said. "That's true of mammals and other multi-cellular organisms. But we didn't know if that was true of phytoplankton. Now we can make predictions about community composition based off temperature. This will help us predict whether larger diatoms will be able to persist in warming waters."

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Parents who use humor have better relationships with their children, study finds

They say that laughter is the best medicine, but it could be a good parenting tool too, according to a new study led by researchers from Penn State.

In a pilot study, the research team found that most people viewed humor as an effective parenting tool and that a parent or caregiver's use of humor affected the quality of their relationship with their children. Among those whose parents used humor, the majority viewed their relationship with their parents and the way they were parented in a positive light. The researchers published their findings in the journal PLOS One.

"Humor can teach people cognitive flexibility, relieve stress, and promote creative problem solving and resilience," said Benjamin Levi, professor of pediatrics and humanities at Penn State College of Medicine and senior author of the study. "My father used humor and it was very effective. I use humor in my clinical practice and with my own children. The question became, how does one constructively use humor?"

While aspects of humor and play have been studied across various settings and in child development, the use of humor in parenting hasn't been formally studied, the researchers said.

"There's an interesting parallel between business and parenting, which are both hierarchical. In business, humor has been shown to help reduce hierarchies, create better environments for collaboration and creativity and diffuse tension," said first author Lucy Emery, who was a medical student at Penn State College of Medicine at the time of the research and currently a pediatrics resident at Boston Children's Hospital. "While parent-child relationships are more loving than business relationships, stressful situations happen a lot when parenting. Humor can help diffuse that tension and hierarchy and help both parties feel better about a stressful situation."

This preliminary research was a first step to examine how people view the relationship between humor, their experience being parented and their experience of parenting. The study will help lay the groundwork for understanding how to use humor constructively and the kinds of situations that are riskier for using humor.

They surveyed 312 people between the ages of 18 and 45. More than half said they were raised by people who used humor and 71.8% agreed that humor can be an effective parenting tool. The majority said they do or plan to use humor with their children and believe that it has more potential benefit than harm.

The team also found a correlation between a parent's use of humor and the way their children, who are now adults, viewed the way they were parented and their relationship with their parents. Of those who reported that their parents used humor, 50.5% said they had a good relationship with their parents and 44.2% reported they felt their parents did a good job parenting them. On the other hand, of those who said their parents didn't use humor, only 2.9% reported a good relationship with their parents and 3.6% reported that they thought their parents did a good job parenting them.

While it's not surprising that parents would use humor with their children if they were raised by caregivers who did the same, Levi said the stark differences between the two groups was unexpected.

The research team is expanding on this preliminary study and are surveying a larger and more diverse cohort of parents as well as collecting qualitative research based on parents' experience using humor.

"My hope is that people can learn to use humor as an effective parenting tool, not only to diffuse tension but develop resilience and cognitive and emotional flexibility in themselves and model it for their children," Levi said.

Erik Lehman, biostatistician at Penn State, and Anne Libera, director of comedy studies at Chicago's The Second City, also contributed to the paper.

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As temperatures break records, many are unaware of symptoms of heat-related illnesses

With NASA data showing that July 22, 2024, was the hottest day on record and indications that July may have been the hottest month, an Annenberg Public Policy Center survey conducted in mid-July found that most people know three of the symptoms of a heat-related illness but do not know the location of their nearest cooling center. At the same time, increasing numbers of people think that heat waves are becoming more frequent and intense and affecting their daily activities.

Knowledge of cooling centers in the case of extreme heat

Although the locations of cooling centers, or indoor air-conditioned facilities such as libraries, community and senior centers, schools are publicized by city governments on hot days, many of those surveyed report being unaware of where to find one. Two-thirds of respondents (67%) say they do not know the location of a cooling center to which they could go to in case of extreme heat, a number statistically unchanged from last November. "Communities must do a better job of making the public, especially the most vulnerable, aware of these centers," said Ken Winneg, managing director of survey research at APPC.

More today see link between extreme heat and climate change.

When compared with an APPC survey in November 2023, significantly more people now say that climate change is increasing the risk of heat-related illnesses, respiratory diseases, and insect-borne diseases. Two-thirds (67%) hold this view vs. just under 6 in 10 (58%) in November 2023.

More people indicate that heat waves in the United States are becoming more frequent and intense than in the past. About two-thirds (65%) believe heat waves are becoming more frequent and intense. Fifty-eight percent (58%) felt this way in November 2023, when we last asked the question. About a quarter (24%) believe heat waves are about as frequent and intense as they have always been, statistically unchanged from our earlier survey.

At the same time, the proportion of people who say extreme heat has often or frequently affected their typical daily activities in the past year has increased significantly. Forty-three percent (43%) say extreme outdoor heat has often (22%) or frequently (21%) affected their daily activities, an 8-point increase compared with November 2023 (35% in total said either "often" or "frequently").

Signs of heat-related illnesses

Notably, most people also know three of the telltale signs of heat-related illnesses:

• Dizziness (89% compared to 86% in August 2022)
• Nausea (83% compared to 79% in August 2022)
• Hot, red, dry, or damp skin (72%, statistically unchanged from August 2022)
• Cold, pale, and clammy skin (42%, statistically unchanged from August 2022).

Public understands some extreme heat risks better than others

Thinking about the next 10 years, just under 6 in 10 (58%) think that people in their community will be more likely to experience heat stroke caused by extreme heat waves. This is significantly higher than in November 2023 when just over half (52%) said they thought people in their community would be more likely to experience heat stroke caused by extreme heat waves in the next 10 years.

However, only 3 in 10 (30%) know that a pregnant person in the U.S. who is exposed to extreme heat is more likely to deliver their baby early than a pregnant person who is not exposed to extreme heat. About a quarter (23%) incorrectly say that a pregnant person in the U.S. is either less or just as likely to deliver a baby early. Forty-seven percent (47%) are unsure which is correct.

Broad awareness that heat-related deaths are most common among seniors

Two-thirds (67%) know that heat-related deaths are most common among older adults, aged 65 or older, slightly but significantly higher than in August 2022 (62%).

Preventing heat-related illnesses

Nearly all (92%) know that drinking water is better to prevent heat-related illnesses than drinking sugary drinks.

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Millions of years for plants to recover from global warming

Scientists often seek answers to humanity's most pressing challenges in nature. When it comes to global warming, geological history offers a unique, long-term perspective. Earth's geological history is spiked by periods of catastrophic volcanic eruptions that released vast amounts of carbon into the atmosphere and oceans. The increased carbon triggered rapid climate warming that resulted in mass extinctions on land and in marine ecosystems. These periods of volcanism may also have disrupted carbon-climate regulation systems for millions of years.

Ecological imbalance

Earth and environmental scientists at ETH Zurich led an international team of researchers from the University of Arizona, University of Leeds, CNRS Toulouse, and the Swiss Federal Institute for Forest Snow and Landscape Research (WSL) in a study on how vegetation responds and evolves in response to major climatic shifts and how such shifts affect Earth's natural carbon-climate regulation system.

Drawing on geochemical analyses of isotopes in sediments, the research team compared the data with a specially designed model, which included a representation of vegetation and its role in regulating the geological climate system. They used the model to test how the Earth system responds to the intense release of carbon from volcanic activity in different scenarios. They studied three significant climatic shifts in geological history, including the Siberian Traps event that caused the Permian-Triassic mass extinction about 252 million years ago. ETH Zurich professor, Taras Gerya points out, "The Siberian Traps event released some 40,000 gigatons (Gt) of carbon over 200,000 years. The resulting increase in global average temperatures between 5 -- 10°C caused Earth's most severe extinction event in the geologic record."

Move, adapt, or perish

"The recovery of vegetation from the Siberian Traps event took several millions of years and during this time Earth's carbon-climate regulation system would have been weak and inefficient resulting in long-term climate warming," explains lead author, Julian Rogger, ETH Zurich.

Researchers found that the severity of such events is determined by how fast emitted carbon can be returned to Earth's interior -- sequestered through silicate mineral weathering or organic carbon production, removing carbon from Earth's atmosphere. They also found that the time it takes for the climate to reach a new state of equilibrium depended on how fast vegetation adapted to increasing temperatures. Some species adapted by evolving and others by migrating geographically to cooler regions. However, some geological events were so catastrophic that plant species simply did not have enough time to migrate or adapt to the sustained increase in temperature. The consequences of which left its geochemical mark on climate evolution for thousands, possibly millions, of years.

Today's human-induced climate crisis

What does this mean for human induced climate change? The study found that a disruption of vegetation increased the duration and severity of climate warming in the geologic past. In some cases, it may have taken millions of years to reach a new stable climatic equilibrium due to a reduced capacity of vegetation to regulate Earth's carbon cycle.

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Long-distance relationship revealed in the seemingly random behavior of bowhead whales

Applying chaos theory to the movement of iconic arctic whales uncovered a 24-hour diving cycle and a long-range (~100 km) synchronization.

Bowhead whales are among the largest and longest-lived mammals in the world.

They play a vital role in the marine ecosystems of the Arctic Ocean, yet relatively little is known about their foraging and diving behaviors.

Now, in a paper to be published in the journal Physical Review Research, a team of scientists from Japan, Greenland and Denmark have detected patterns in the whales' behavior that could offer clues into how they forage and socialize.

Associate Professor Evgeny A. Podolskiy at the Arctic Research Center, Hokkaido University, Professor Jonas Teilmann at the Department of Ecoscience, Aarhus University, and Professor Mads Peter Heide-Jørgensen at the Department of Birds and Mammals, Greenland Institute of Natural Resources, studied 144 days of diving records of 12 bowhead whales tagged in Disko Bay, West Greenland.

Because whale diving behavior can be seen as a chaotic, self-sustained oscillation that balances the need for food at depths with the need for oxygen at the surface, the researchers used a dynamical systems chaos approach to uncover patterns within the apparently disorderly collective behavior.

Their analysis detected a 24-hour cycle of diving during the spring, with the whales swimming deepest in the afternoon to track the daily movement of their prey towards the surface, a phenomenon known as the diel vertical migration.

"We find that foraging whales dive deeper during the daytime in spring, with this diving behavior being in apparent synchrony with their vertically migrating prey," said Heide-Jørgensen.

"Until now, this hasn't been shown for spring, and remained contradictory for autumn."

The research team also made the surprising discovery of two bowhead whales diving in synchrony over the course of a week at a time, even when they were around one hundred kilometers apart.

The pair -- one female and one of unknown sex -- were sometimes as close as five kilometers and sometimes hundreds of kilometers apart, yet they would closely time their diving bouts for durations of up to a week, although to different depths.

The synchronization was observed when they were within acoustic range of each other, which can exceed 100 kilometers, although the researchers didn't record the whales' sounds to determine whether they were interacting, as it remains a technically challenging task.

"Without direct observations, such as recordings of the two whales, it isn't possible to determine that the individuals were exchanging calls," said Teilmann, nevertheless, "the observed subsurface behavior might be the first evidence supporting the acoustic herd theory of long-range signaling in baleen whales proposed by Payne and Webb back in 1971."

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