Reaching for the (invisible) stars

Supernovae-stellar explosions as bright as an entire galaxy-have fascinated us since time immemorial. Yet, there are more hydrogen-poor supernovae than astrophysicists can explain. Now, a new Assistant Professor at the Institute of Science and Technology Austria (ISTA) has played a pivotal role in identifying the missing precursor star population. The results, now published in Science, go back to a conversation the involved professors had many years ago as junior scientists.

Some stars do not simply die down, but explode in a stellar blast that could outshine entire galaxies. These cosmic phenomena, called supernovae, spread light, elements, energy, and radiation in space and send galactic shock waves that could compress gas clouds and generate new stars. In other words, supernovae shape our universe. Among these, hydrogen-poor supernovae from exploding massive stars have long puzzled astrophysicists. The reason: scientists have not been able to put their finger on their precursor stars. It is almost as if these supernovae appeared out of nowhere.

"There are many more hydrogen-poor supernovae than our current models can explain. Either we can't detect the stars that mature on this path, or we must revise all our models," says ISTA Assistant Professor Ylva Götberg. She pioneered this work together with Maria Drout, an Associated Faculty Member of the Dunlap Institute for Astronomy & Astrophysics, University of Toronto, Canada. "Single stars would typically explode as hydrogen-rich supernovae. Being hydrogen-poor indicates that the precursor star must have lost its thick hydrogen-rich envelope. This happens naturally in a third of all massive stars through envelope stripping by a binary companion star," says Götberg. Now, Götberg and Drout combined their areas of expertise in theoretical modeling and observation to hunt down the missing stars. Their quest is successful: they document a first-of-its-kind star population that finally bridges a large knowledge gap and sheds light on the origin of hydrogen-poor supernovae.

Binary stars and envelope stripping

The stars that Götberg and Drout search for go in pairs: interlocked in a binary star system. Some binary systems are well-known to us Earthlings: these include the brightest star in our night sky, Sirius A, and its faint companion star Sirius B. The Sirius binary system is located only 8.6 light-years away from Earth-a stone's throw in cosmic terms. This explains Sirius A's observed brightness in our night sky.

Astrophysicists expect the missing stars to be initially formed from massive binary systems. In a binary system, the stars would orbit around one another until the more massive star's thick, hydrogen-rich envelope expands. Eventually, the expanding envelope experiences a stronger gravitational pull to the companion star than to its own core. This causes a transfer of mass to begin, which eventually leads the entire hydrogen-rich envelope to be stripped off, leaving the hot and compact helium core exposed-more than 10 times hotter than the Sun's surface. This is precisely the type of stars that Götberg and Drout are looking for. "Intermediate mass helium stars stripped through binary interaction are predicted to play important roles in astrophysics. Yet, they were not observed until now," says Götberg. In fact, there is an important mass gap between the known classes of helium stars: the more massive Wolf-Rayet (WR) stars have more than 10 times the Sun's mass, and the low-mass subdwarf stars could have around half the Sun's mass. However, models have predicted the precursors of hydrogen-poor supernovae to lie between 2 and 8 solar masses following stripping.

Not just a needle in the haystack

Before Götberg and Drout's study, only one star was found to fulfill the expected mass and composition criteria and was called "Quasi-WR" (or "Almost Wolf-Rayet"). "Yet, the stars that follow this path have such a long lifetime that many must be scattered all over the observable universe," says Götberg. Did the scientists simply not "see" them? Thus, Götberg and Drout drew on their complementary expertise. With the help of UV photometry and optical spectroscopy, they identified a population of 25 stars that are consistent with the expectations for intermediate-mass helium stars. The stars are located in two well-studied neighboring galaxies, the Large and the Small Magellanic Clouds. "We showed that these stars were bluer than the stellar birthline, the bluest phase in a single star's lifetime. Single stars mature by evolving towards the redder region of the spectrum. A star only shifts in the opposite direction if its outer layers are removed-something that is expected to be common in interacting binary stars and rare among single massive stars," explains Götberg.

The scientists then verified their candidate star population using optical spectroscopy: they showed that the stars had strong spectral signatures of ionized helium. "Strong ionized helium lines tell us two important things: first, they confirm that the stars' outermost layers are dominated by helium and, second, that their surface is very hot. This is what happens to stars left as an exposed, compact, helium-rich core following stripping," says Götberg. Yet, both stars in a binary system contribute to the observed spectra. Thus, this technique allowed the researchers to classify their candidate population depending on which star contributed the most to the spectrum. "This work allowed us to find the missing population of intermediate-mass, stripped helium stars, the predicted progenitors of hydrogen-poor supernovae. These stars have always been there and there are probably many more out there. We must simply come up with ways to find them," says Götberg. "Our work may be one of the first attempts, but there should be other ways possible."

From graduate students at a conference to group leaders

The idea behind this project sparked in a discussion following a talk by Götberg at a conference that she and Drout attended during their graduate studies. Both scientists, then Early Career Researchers reaching for the stars, are now group leaders in their field. Götberg joined ISTA in September following her research at the Carnegie Observatories in Pasadena, California, as a NASA Hubble postdoctoral fellow. At ISTA, Götberg joins the Institute's growing ranks of young group leaders in astrophysics and leads her own group focused on studying the binary interactions of stars.

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Can you change a chicken into a frog, a fish or a chameleon?

Gastrulation is one of the most important phases in early embryonic development. Before gastrulation, vertebrate embryos are simple two-dimensional sheets of cells. By the end of gastrulation, an embryo will have begun to differentiate distinct cell types, set up the basic axes of the body and internalize some of the precursors for organs in a three-dimensional structure. Amniotes, like chickens and humans, will have developed a primitive streak, the precursor to the brain and skin, while fish and amphibians will have developed a spherical-shaped blastopore.

Gastrulation is a feat of self-organization, requiring the ballet-like coordinated movements of hundreds to tens of thousands of cells.

But, despite its importance in development, scientists only partially understand the underlying mechanisms that coordinate this large-scale movement of cells.

Now a team of researchers from the Harvard, the University of California San Diego and the University of Dundee in the U.K., have developed a theoretical framework that can reproduce and predict the patterns associated with gastrulation in a chicken embryo.

Building on their experimental findings published earlier this year in Science Advances, and using a combination of theory and experiment, the researchers demonstrated that small changes in cell parameters and behavior can have a dramatic impact on the resulting gastrulation patterns.

The new research was also published in Science Advances.

"Linking the developmental processes underlying morphogenesis in an organism to the variations of these same processes across evolution is an old question in biology," said L. Mahadevan, the Lola England de Valpine Professor of Applied Mathematics at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), and Professor of Organismic and Evolutionary Biology, and of Physics in the Faculty of Arts and Sciences (FAS) and senior author of the paper.

"Moving away from the gene-centric molecular focus on this question, we asked if there are emergent biophysical principles that operate on the multi-cellular level and can help explain the self-organized gastrulation patterns from both a developmental and an evolutionary perspective."

Working closely with experimentalists, the researchers developed a theoretical and computational model that could recreate the movement of the epithelial layer of cells in chick embryos during gastrulation.

The team then identified two parameters -- one related to the initial distribution of cells in an embryo and the other related to cell behavior -- to tweak during gastrulation.

"When we changed these two parameters in the model, which was only informed by the mechanisms of chick development, it remarkably showed gastrulation patterns naturally seen in other species," said Mattia Serra, first author of the paper and former Schmidt Science fellow in the Mahadevan group.

Serra is an Assistant Professor in Physics at UC San Diego.

Consistent with the computational results, experiments show that perturbing the same parameters in vivo in a chick embryo caused the chick to form a disk-like blastopore, seen in frogs, a ring-like circular primitive streak, like those seen in fish, or an elongated elliptical canal-like streak seen in chameleon.

"Our work suggests that the general biophysical principles underlying active self-organized flows and forces during embryogenesis have the power to explain developmental processes and their evolutionary variations across different species of vertebrates," said Mahadevan.

"We were surprised to see how simple mechanochemical rules could predict highly distinct coherent flows of thousands of cells measured in a living chick embryo," said Serra.

This research not only sheds light on the principles for self- organization in early development but could also help researchers understand the evolutionary history of developmental processes and suggest ways to control the development of synthetic organoids.

This research looked at the early stages of development, when the embryo is just transforming from two-dimensions into three.

Next, Mahadevan wants to understand what happens when the embryo starts to fold and buckle to create the more complex shapes of organs and eventually whole organisms.

"Using our knowledge of developmental processes at the molecular and cellular level, we eventually hope to provide an integrated framework for how cells form into tissues and tissues into organs, towards a better understanding of morphogenesis," said Mahadevan.

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Coevolution helps Santa's reindeer feast after flight

When Santa's exhausted reindeer finally set down their sleigh in the deep snow of the North Pole early Christmas morning, it's not Rudolph's radiant red nose that will help them find sustenance in the barren landscape.

Instead, researchers from Dartmouth and the University of St. Andrews in Scotland report that the eyes of Rudolph and his reindeer brethren may have evolved so that they can spot their favorite food during dark and snowy Arctic winters, according to a new study in the journal i-Perception.

The findings help explain the long-standing scientific mystery as to why reindeer can see light in the ultraviolet (UV) spectrum -- and add intrigue to the smiling airborne ungulates popularized in the classic story by 1926 Dartmouth graduate Robert L. May.

"Reindeer are so cool, but many people think about them only at Christmas," Nathaniel Dominy, first author of the study and the Charles Hansen Professor of Anthropology at Dartmouth says.

"Now is a good time to alert people to their extraordinary visual system."

Reindeer subsist primarily on reindeer moss, or Cladonia rangiferina, which isn't a moss but actually a species of algae-fungus fusion known as lichen.

C. rangiferina forms thick crunchy carpets across northern latitudes and is so integral to the survival of reindeer that even its formal name stems from the scientific term for reindeer, Rangifer.

The researchers worked in the Cairngorms mountains in the Scottish Highlands, which host Britain's only reindeer herd -- reintroduced from Scandinavia after being hunted to extinction locally -- and more than 1,500 species of lichen.

Despite these options, reindeer in the Cairngorms rely on C. rangiferina during the winter.

"A peculiar trait of reindeer is their reliance on this one type of lichen," Dominy says.

"It's unusual for an any animal to subsist so heavily on lichens, let alone such a large mammal."

To the human eye, the white lichen is invisible against the snowy backdrop of an Arctic winter.

But Dominy and co-authors Catherine Hobaiter and Julie Harris from St. Andrews discovered that C. rangiferina and a few other lichen species that supplement the reindeer diet absorb UV light.

Spectral data from the lichen and light filters calibrated to mimic reindeer vision revealed that these organisms appear to reindeer as dark patches against an otherwise brilliant landscape, making them easier to locate.

"Getting a visual approximation of how reindeer might see the world is something other studies haven't done before," says Dominy, who published a paper in 2015 on how Rudolph's red nose would've acted as an effective foglamp in the haze of winter.

"If you can put yourself in their hooves looking at this white landscape, you would want a direct route to your food," he says.

"Reindeer don't want to waste energy wandering around searching for food in a cold, barren environment. If they can see lichens from a distance, that gives them a big advantage, letting them conserve precious calories at a time when food is scarce."

Previous research has shown that reindeer eyes change between summer and winter, Dominy says.

Their tapetum -- the light-enhancing membrane that gives many animals "shiny" eyes -- transitions in winter from the golden color most animals have to a vivid blue that is thought to amplify the low light of polar winter.

"If the color of the light in the environment is primarily blue, then it makes sense for the eye to enhance the color blue to make sure a reindeer's photoreceptors are maximizing those wavelengths," Dominy says.

But the blue tapetum also lets up to 60% of ultraviolet light pass through to the eye's color sensors.

That means that reindeer see the winter world as a shade of purple, similar to how a person would see a room with a black light -- UV-reflecting surfaces such as snow shine brightly while UV-absorbing surfaces are starkly dark.

The researchers recount how scientists have sought to answer why the eyes of an Arctic animal that is active during the day would be receptive to the UV light that would be reflecting off of every snow-covered surface.

But their study suggests that the answer is tied to what UV light doesn't reflect from -- C. rangiferina and other bushy lichens.

Given the importance of lichens in the reindeer diet, the researchers report, it is possible that the animal's eyes are optimized to single out this food staple at the time of year it would be most difficult to find.

Read more at Science Daily

Researchers, Coast Salish people analyze 160-year-old indigenous dog pelt in the Smithsonian's collection

Researchers from the Smithsonian's National Museum of Natural History led a new analysis that sheds light on the ancestry and genetics of woolly dogs, a now extinct breed of dog that was a fixture of Indigenous Coast Salish communities in the Pacific Northwest for millennia. Anthropologist Logan Kistler and evolutionary molecular biologist Audrey Lin analyzed genetic clues preserved in the pelt of "Mutton," the only known woolly dog fleece in the world, to pinpoint the genes responsible for their highly sought-after woolly fur.

The study's findings, published today, Dec. 14, in the journal Science, include interviews contributed by several Coast Salish co-authors, including Elders, Knowledge Keepers and Master Weavers, who provided crucial context about the role woolly dogs played in Coast Salish society.

"Coast Salish traditional perspective was the entire context for understanding the study's findings," said Kistler, the museum's curator of archaeobotany and archaeogenomics.

Coast Salish tribal nations in Washington state and British Columbia bred and cared for woolly dogs for thousands of years. Prized for their thick undercoats, the dogs were sheared like sheep and often kept in pens or on islands to carefully manage their breeding and to care for the canines' health and vitality. Coast Salish weavers used the dogs' wool to craft blankets and other woven items that served a variety of ceremonial and spiritual purposes. Woolly dogs themselves possessed spiritual significance and were often treated as beloved family members. As emblems for many Coast Salish communities, woolly dogs adorned woven baskets and other art forms.

By the mid-19th century, this once thriving dog wool-weaving tradition was in decline. In the late 1850s, naturalist and ethnographer George Gibbs cared for a woolly dog named Mutton. When Mutton died in 1859, Gibbs sent his pelt to the nascent Smithsonian Institution, where the fleece has resided ever since. However, few were aware of the pelt's existence until it was rediscovered in the early 2000s.

Lin first learned about Mutton when she was a Peter Buck postdoctoral fellow at the museum in 2021.

"When I saw Mutton in person for the first time, I was just overcome with excitement," said Lin, who is now a postdoctoral researcher at the American Museum of Natural History. "I had heard from some other people that he was a bit scraggly, but I thought he was gorgeous."

She was surprised to find out that virtually no work had been done on the genetics of woolly dogs, which disappeared around the turn of the 20th century. She teamed up with Kistler and they reached out to several Coast Salish communities to gauge their interest in working together on a potential research project on woolly dogs.

Many in the Coast Salish communities were eager to share their knowledge.

"We were very excited to participate in a study that embraces the most sophisticated Western science with the most established Traditional Knowledge," said Michael Pavel, an Elder from the Skokomish/Twana Coast Salish community in Washington, who remembers hearing about woolly dogs early in his childhood. "It was incredibly rewarding to contribute to this effort to embrace and celebrate our understanding of the woolly dog."

To complement the perspectives they received from Pavel and other Coast Salish people from British Columbia and Washington state (the text from their interviews is available in the study's supplementary materials), Lin, Kistler and their colleagues began analyzing Mutton's genetic code. They sequenced the woolly dog genome and compared it with the genomes of ancient and modern breeds of dogs to determine what set woolly dogs apart. They also identified certain chemical signatures called isotopes in Mutton's pelt to determine the dog's diet and teamed up with noted natural history illustrator Karen Carr to create a life-like reconstruction of what Mutton looked like in the 1850s. Carr's work is the first in-depth reconstruction of a Coast Salish woolly dog in nearly three decades.

Based on the genetic data, the team estimated that woolly dogs diverged from other breeds up to 5,000 years ago -- a date that lines up with archaeological remains from the region. They also discovered that Mutton was genetically similar to pre-colonial dogs from Newfoundland and British Columbia. The researchers estimate that nearly 85% of Mutton's ancestry can be linked to pre-colonial dogs. This ancient ancestry is surprising because Mutton lived decades after the introduction of European dog breeds. This makes it likely that Coast Salish communities continued to maintain woolly dogs' unique genetic makeup until right before the dogs were wiped out.

In total, the team analyzed more than 11,000 different genes in Mutton's genome to determine what gave woolly dogs their fluffy fleece and wool fibers that could be spun together to create yarn. They identified 28 genes that have links to hair growth and follicle regeneration. These included a gene that causes a woolly hair phenotype in humans, and another linked to curly hair in other dogs. Similar genes were even activated in the genomes of woolly mammoths.

However, Mutton's genetics could tell the researchers little about what caused the dogs to decline. Traditionally, scholars have speculated that the arrival of machine-made blankets to the region in the early 19th century made woolly dogs expendable. But insights from Pavel and other traditional experts revealed that it was improbable that such a central part of Coast Salish society could be replaced.

Instead, woolly dogs were likely doomed by numerous factors impacting the Coast Salish tribal nations after European settlers arrived. Due to disease and colonial policies of cultural genocide, displacement and forced assimilation, it likely became increasingly difficult or forbidden for Coast Salish communities to maintain their woolly dogs.

"It was thousands of years of very careful maintenance lost within a couple of generations," Lin said.

But despite their disappearance, the memory of woolly dogs is still embedded into Coast Salish society. And Pavel thinks their understanding of woolly dogs is only getting clearer thanks to the new research effort.

"All of our communities held a certain aspect of knowledge about the woolly dog," Pavel said. "But when woven together, as a result of participating in this study, we now have a much more complete understanding."

Read more at Science Daily

Scientists measure the distance to stars by their music

For most of us, the countless bright spots in the nighttime sky all seem to be stars. But in fact, some of those spots are actually planets, or distant suns, or even entire galaxies located billions of light years away. Just what you're looking at depends on how far it is from Earth. That's why measuring the exact distance to celestial objects is such an important goal for astronomers -- and one of the biggest challenges they're currently tackling.

It was with this in mind that the European Space Agency (ESA) launched the Gaia mission ten years ago.

Data collected by the Gaia satellite are opening up a window into the near Universe, providing astronomic measurements -- such as position, distance from the Earth and movement -- on nearly two billion stars.

At EPFL, the Standard Candles and Distances research group headed by Prof.

Richard Anderson is aiming to measure the current expansion of the Universe and sees Gaia as a valuable tool.

"Gaia increased by a factor of 10,000 the number of stars whose parallaxes are measured thanks to a massive gain in accuracy over its predecessor, the ESA Hipparcos mission," he says.

Today, scientists use parallaxes to calculate the distance to stars.

This method involves measuring parallax angles, with the help of the satellite, through a form of triangulation between Gaia's location in space, the Sun and the star in question.

The farther away a star, the more difficult the measurement because parallax gets smaller the larger the distance.

Despite the resounding success of Gaia, the measurement of parallax is complex, and there remain small systematic effects that must be checked and corrected in order for Gaia parallaxes to reach their full potential.

This is what scientists from EPFL and the University of Bologna, in Italy, have been working on, through calculations performed on over 12,000 oscillating red giant stars* -- the biggest sample size and most accurate measurements to date.

"We measured the Gaia biases by comparing the parallaxes reported by the satellite with parallaxes of the same stars that we determined using asteroseismology," says Saniya Khan, a scientist in Anderson's research group and the lead author of a study published today in Astronomy & Astrophysics.

Stellar earthquakes

In the same way that geologists study the Earth's structure using earthquakes, astronomers use asteroseismology, and specifically stars' vibrations and oscillations, to glean information about their physical properties.

Stellar oscillations are measured as tiny variations in light intensity and translated into sound waves, giving rise to a frequency spectrum of these oscillations.

"The frequency spectrum lets us determine how far away a star is, enabling us to obtain asteroseismic parallaxes," says Khan.

"In our study, we listened to the 'music' of a vast number of stars -- some of them 15,000 light-years away!"

To turn sounds into distance measurements, the research team started with a simple fact.

The speed with which sound waves propagate across space depends on the temperature and density of the star's interior.

"By analyzing the frequency spectrum of stellar oscillations, we can estimate the size of a star, much like you can identify the size of a musical instrument by the kind of sound it makes -- think of the difference in pitch between a violon and a cello," says Andrea Miglio, a full professor at the University of Bologna's Department of Physics and Astronomy and the study's third author.

Sophisticated analyses

Having thus calculated a star's size, the astronomers then determined its luminosity and compared this figure to the luminosity perceived here on Earth.

They coupled this information with temperature and chemical-composition readings obtained from spectroscopy and ran these data through sophisticated analyses to calculate the distance to the star.

Finally, the astronomers compared the parallaxes obtained in this process with those reported by Gaia in order to check the accuracy of the satellite's measurements.

"Asteroseismology is the only way we can check Gaia's parallax accuracy across the full sky -- that is, for both low- and high-intensity stars," says Anderson.

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Beef farming that keeps cattle on lifelong grass diets may have higher carbon footprint

Beef operations that keep cattle on lifelong grass-based diets may have an overall higher carbon footprint than those that switch cattle to grain-based diets partway through their lives. Daniel Blaustein-Rejto of the Breakthrough Institute, USA, and colleagues present these findings in the open-access journal PLOS ONE on December 13.

Cattle on lifelong grass diets are known as "pasture finished," while those that switch from grass to grain before slaughter are "grain finished." Prior research has suggested that pasture-finished beef operations have a higher carbon footprint than grain-finished operations.

However, most studies have limited their focus to the amount of greenhouse gases emitted directly by beef production without considering other factors that may affect the overall carbon footprint.

To help deepen understanding, Blaustein-Rejto and colleagues calculated and compared the carbon footprint of 100 beef operations located in 16 countries.

In addition to direct greenhouse gas emissions, their calculations incorporated soil carbon sequestration -- the capture and long-term storage in pasture soils of atmospheric carbon, often in the form of dead plants and cattle waste.

They also accounted for the carbon opportunity cost -- the carbon that would have been sequestered if the land had native ecosystems instead of being used for beef production.

Extensive statistical analysis showed that the pasture-finished operations produce 20 percent more greenhouse gases than grain-finished operations -- in line with prior studies.

However, after incorporating soil carbon sequestration and carbon opportunity cost, the total carbon footprint of pasture-finished operations was 42 percent higher, likely due to its more intense usage of land.

Further analysis suggested that an increase in land use intensity is indeed strongly associated with a bigger overall carbon footprint for beef operations.

The calculations also suggest that, averaging across all operations in the study, carbon opportunity costs may contribute even more to an operation's overall carbon footprint than its direct greenhouse gas emissions.

The researchers say their findings emphasize the need for climate mitigation efforts to account for carbon opportunity costs of beef production.

With pasture-finished beef often being seen as more premium, carbon footprint data may also provide important additional information to aid consumer choice.

Read more at Science Daily

AI provides more accurate analysis of prehistoric and modern animals, painting picture of ancient world

A new Rice University study of the remains of prehistoric and modern African antelopes found that AI technology accurately identified animals more than 90% of the time compared to humans, who had much lower accuracy rates depending on the expert.

Composite images of teeth from five different antelope tribes analyzed and identified by artificial intelligence.

Photo courtesy of Manuel Domínguez-Rodrigo.

Identifying these animals and their habits helps paint a broader picture of ancient ecosystems, and with the assistance of this new technology, it can be done with more speed and accuracy than previously done by paleontologists, according to the study.

"African bovid tribe classification using transfer learning and computer vision" appeared in a recent edition of Annals of the New York Academy of Sciences.

The study outlines the groundbreaking AI technology used to analyze prehistoric livestock remains.

So why does it matter how these ancient animals lived and what they ate?

According to Manuel Domínguez-Rodrigo, visiting professor of anthropology at Rice, co-director of Madrid's Institute of Evolution in Africa and professor of prehistory at the University of Alcalá in Spain, the study sheds light on how the ecology of the time affected the evolution of mammal communities including humans, who over the past two million years have become highly dependent on other mammals.

"The evolution of ecosystems in Africa is of major relevance to understand what shaped our own evolution as humans," Domínguez-Rodrigo said.

"Our prehistoric ancestors were highly dependent on resources available in different habitats of African savanna ecosystems. Using fossil mammals -- highly specialized in their adaptations to different habitats -- to reconstruct these landscapes has been the most used method to interpret their ecology. Identifying those mammals by their teeth has not always been straightforward and was subjected to a high degree of expert knowledge and bias. Now we can do that with much more confidence. This will enable us to understand past environments but also understand better modern landscapes too when documenting the dead animals that they still contain."

And thanks to this technology, whose application to paleobiology is pioneered in Domínguez-Rodrigo's lab, he says archaeologists can now analyze information far more quickly and accurately than before.

"These AI methods are a revolution for the studies of paleobiology and human evolution in particular," he said.

"They provide an objective, replicable way of identifying animals, including the degree of confidence with which identifications are made."

Domínguez-Rodrigo said the success of AI in other fields, such as image-based medicine, was a proof of concept for its widespread application to other fields.

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'Long flu' has emerged as a consequence similar to long COVID

Since the COVID-19 pandemic began, extensive research has emerged detailing the virus's ability to attack multiple organ systems, potentially resulting in a set of enduring and often disabling health problems known as long COVID. Now, new research from Washington University School of Medicine in St. Louis and the Veterans Affairs St. Louis Health Care System indicates that people hospitalized with seasonal influenza also can suffer long-term, negative health effects, especially involving their lungs and airways.

The new study comparing the viruses that cause COVID-19 and the flu also revealed that in the 18 months after infection, patients hospitalized for either COVID-19 or seasonal influenza faced an increased risk of death, hospital readmission, and health problems in many organ systems. Further, the time of highest risk was 30 days or later after initial infection.

"The study illustrates the high toll of death and loss of health following hospitalization with either COVID-19 or seasonal influenza," said senior author Ziyad Al-Aly, MD, a clinical epidemiologist at Washington University. "It's critical to note that the health risks were higher after the first 30 days of infection. Many people think they're over COVID-19 or the flu after being discharged from the hospital. That may be true for some people. But our research shows that both viruses can cause long-haul illness."

The findings are published Dec. 14 in The Lancet Infectious Diseases.

The statistical analysis spanned up to 18 months post-infection and included a comparative evaluation of risks of death, hospital admissions and 94 adverse health outcomes involving the body's major organ systems.

"A review of past studies on COVID-19 versus the flu focused on a short-term and narrow set of health outcomes," said Al-Aly, who treats patients within the VA St. Louis Health Care System and is an assistant professor of medicine at Washington University. "Our novel approach compared the long-term health effects of a vast array of conditions. Five years ago, it wouldn't have occurred to me to examine the possibility of a 'long flu.' A major lesson we learned from SARS-CoV-2 is that an infection that initially was thought to only cause brief illness also can lead to chronic disease. This revelation motivated us to look at long-term outcomes of COVID-19 versus flu.

"We wanted to know whether and to what degree people with flu also experience long-term health effects," Al-Aly said. "The big answer is that both COVID-19 and the flu led to long-term health problems, and the big aha moment was the realization that the magnitude of long-term health loss eclipsed the problems that these patients endured in the early phase of the infection. Long COVID is much more of a health problem than COVID, and long flu is much more of a health problem than the flu."

However, the overall risk and occurrence of death, hospital admissions, and loss of health in many organ systems are substantially higher among COVID-19 patients than among those who have had seasonal influenza, Al-Aly said. "The one notable exception is that the flu poses higher risks to the pulmonary system than COVID-19," he said. "This tells us the flu is truly more of a respiratory virus, like we've all thought for the past 100 years. By comparison, COVID-19 is more aggressive and indiscriminate in that it can attack the pulmonary system, but it can also strike any organ system and is more likely to cause fatal or severe conditions involving the heart, brain, kidneys and other organs."

The researchers analyzed de-identified medical records in a database maintained by the U.S. Department of Veterans Affairs, the nation's largest integrated health-care delivery system. They evaluated information involving 81,280 patients hospitalized for COVID-19 at some point from March 1, 2020, through June 30, 2022, as well as 10,985 patients hospitalized for seasonal influenza at some point from Oct. 1, 2015, through Feb. 28, 2019.

Patients represented multiple ages, races and sexes.

Regarding both viruses, patient vaccination status did not affect results. Those in the COVID-19 cohort were hospitalized during the pre-delta, delta and omicron eras.

During the overall 18-month study period, patients who had COVID-19 faced a 50% higher risk of death than those with seasonal influenza. This corresponded to about eight more deaths per 100 persons in the COVID-19 group than among those with the flu.

Although COVID-19 showed a greater risk of health loss than seasonal influenza, infection with either virus carried significant risk of disability and disease. The researchers found COVID-19 exhibited increased risk of 68% of health conditions examined across all organ systems (64 of the 94 adverse health outcomes studied), while the flu was associated with elevated risk of 6% of health conditions (six of the 94) -- mostly in the respiratory system.

Also, over 18 months, COVID-19 patients experienced an increased risk of hospital readmission as well as admission to an intensive care unit (ICU). For every 100 persons in each group, there were 20 more hospital admissions and nine more ICU admissions in COVID-19 than flu.

"Our findings highlight the continued need to reduce the risk of hospitalization for these two viruses as a way to alleviate the overall burden of health loss in populations," Al-Aly said. "For both COVID-19 and seasonal influenza, vaccinations can help prevent severe disease and reduce the risk of hospitalizations and death. Optimizing vaccination uptake must remain a priority for governments and health systems everywhere. This is especially important for vulnerable populations such as the elderly and people who are immunocompromised."

In both COVID-19 and the flu, more than half of death and disability occurred in the months after infection as opposed to the first 30 days, the latter of which is known as the acute phase.

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Unexpected chemistry reveals cosmic star factories´ secrets

Two galaxies in the early universe, which contain extremely productive star factories, have been studied by a team of scientists led by Chalmers University of Technology in Sweden. Using powerful telescopes to split the galaxies' light into individual colours, the scientists were amazed to discover light from many different molecules -- more than ever before at such distances. Studies like this could revolutionise our understanding of the lives of the most active galaxies when the universe was young, the researchers believe.

When the universe was young, galaxies were very different from today's stately spirals, which are full of gently-shining suns and colourful gas clouds. New stars were being born, at rates hundreds of times faster than in today's universe. Most of this however, was hidden behind thick layers of dust, making it a challenge for scientists to discover these star factories' secrets -- until now. By studying the most distant galaxies visible with powerful telescopes, astronomers can get glimpses of how these factories managed to create so many stars.

In a new study, published in the journal Astronomy & Astrophysics, a team of scientists led by Chalmers astronomer Chentao Yang, used the telescopes of NOEMA (NOrthern Extended Millimetre Array) in France to find out more about how these early star factories managed to create so many stars. Yang and his colleagues measured light from two luminous galaxies in the early universe -- one of them classified as a quasar, and both with high rates of star formation.

"We knew these galaxies were prodigious star factories, perhaps amongst the biggest the universe has ever seen. To be able to find out how they work, we measured their light at wavelengths around one millimetre, hoping to collect new clues," says Chentao Yang.

Dramatic chemistry in the distant galaxies excites the astronomers

The measurements proved to be successful beyond the scientists' expectations. In the light they recorded from both galaxies, they identified traces of many different kinds of molecules. From deep within these galaxies, light is emitted in many different wavelengths from the clouds of gas and dust where new stars are born.

"It's an amazing explosion of colour, in shades that the human eye can't see. But by combining our observations with our knowledge of physics and chemistry, we can understand what the colours mean, and see what differences there are between different galaxies," explains Sergio Martín, astronomer at ESO and Joint ALMA Observatory, Chile, and member of the research team.

By analysing each galaxy's spectrum -- the individual colours of their light -- the scientists were able to identify 13 molecules, several of which have never been seen before in such distant galaxies. Each molecule gives different clues about the temperature, pressure, and density in the space between the stars, and about how starlight, radiation and matter interact -- providing key new information on the physical and chemical conditions in these galaxies.

"Interpreting the signals is a challenge. We are seeing part of the electromagnetic spectrum that is hard to observe in nearby galaxies. But thanks to the expansion of the universe, the light from distant galaxies like these is shifted to longer wavelengths that we can see with radio telescopes observing in the sub-millimetre," says Chentao Yang.

More like a neon-lit city than a night under the stars

The two galaxies studied by the team are so far away that their light takes almost 13 billion years to reach us.

"Looking at these galaxies is less like a night under the stars and more like seeing a city lit with neon lights," says Susanne Aalto, Chalmers astronomer and team member.

Astronomers are used to taking pictures of our galaxy's star factories, like the Orion Nebula and the Carina Nebula, she explains.

"In these two distant galaxies, we are instead seeing star factories that are bigger, brighter, full of dust, and different in many ways. The Orion and Carina nebulae are lit up thanks to ultraviolet light from hot, newborn stars. In these two distant galaxies, ultraviolet light can't get past the layers of dust. Much of the illumination is instead thanks to cosmic rays -- high energy particles that can be created by exploding stars, or close to a supermassive black hole," says Susanne Aalto.

The galaxies in the early universe can now tell their stories

While galaxies like these two are rare, the scientists have plans to study more of them, using both NOEMA and its even bigger sister telescope, ALMA (the Atacama Large Millimetre/Submillimetre Array) in Chile. Both telescopes are sensitive to light with wavelengths of around one millimetre.

"Our results show how NOEMA, with its broadband receivers and powerful correlator computer, has opened up new opportunities for studying extreme galaxies like these in the northern sky. From the southern hemisphere, ALMA's planned wideband sensitivity upgrades will offer even more exciting prospects. The most remarkable galaxies in the early universe are finally able to tell their stories through their molecules," says Pierre Cox, astronomer at CNRS and Sorbonne Université, France.

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Extremely rare bird captured on film

A striking and extremely rare half female, half male bird has been spotted by a University of Otago zoologist.

Sesquicentennial Distinguished Professor Hamish Spencer was holidaying in Colombia when an amateur ornithologist John Murillo pointed out a wild Green Honeycreeper with distinct half green, or female, and half blue, male, plumage.

"Many birdwatchers could go their whole lives and not see a bilateral gynandromorph in any species of bird. The phenomenon is extremely rare in birds, I know of no examples from New Zealand ever.

"It is very striking, I was very privileged to see it," Professor Spencer says.

Photographs of the bird make the discovery even more significant as they are "arguably the best of a wild bilateral gynandromorphic bird of any species ever."

A report on the find, only the second recorded example of gynandromorphism in the species in more than 100 years, has just been published in the Journal of Field Ornithology.

Professor Spencer says gynandromorphs -- animals with both male and female characteristics in a species that usually have separate sexes -- are important for our understanding of sex determination and sexual behaviour in birds.

The main groups in which the phenomenon has been recorded include animal species which feature strong sexual dimorphism; most often insects, especially butterflies, crustaceans, spiders, even lizards and rodents.

"This particular example of bilateral gynandromorphy -- male one side and female the other -- shows that, as in several other species, either side of the bird can be male or female.

"The phenomenon arises from an error during female cell division to produce an egg, followed by double-fertilization by two sperm," he explains.

He hopes the novel discovery will inspire people to "treasure exceptions" as they always reveal something interesting.

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Viking dentistry was surprisingly advanced

Widespread caries and toothache -- but also some dental work and filing of front teeth. Viking Age teeth from Varnhem bear witness to surprisingly advanced dentistry. This has been shown in a study carried out at the University of Gothenburg.

The study examined 3,293 teeth from 171 individuals among the Viking Age population of Varnhem in Västergötland, Sweden.

The site is known for extensive excavations of Viking and medieval environments, including tombs where skeletons and teeth have been preserved well in favorable soil conditions.

The research team from the University of Gothenburg's Institute of Odontology worked with an osteologist from Västergötland's Museum.

The skulls and teeth were transported to Gothenburg, where all the examinations were carried out.

The teeth underwent clinical examinations using standard dentistry tools under bright light.

A number of X-ray examinations were also performed using the same technique used in dentistry, where the patient bites down on a small square imaging plate in the mouth.

Caries and tooth loss

The results, which have been published in the journal PLOS ONE, show that 49% of the Viking population had one or more caries lesions.

Of the adults' teeth, 13% were affected by caries -- often at the roots.

However, children with milk teeth -- or with both milk and adult teeth -- were entirely caries-free.

Tooth loss was also common among adults. The studied adults had lost an average of 6% of their teeth, excluding wisdom teeth, over their lifetimes.

The risk of tooth loss increased with age.

The findings suggest that caries, tooth infections, and toothache were common among the Viking population in Varnhem.

However, the study also reveals examples of attempts to look after teeth in various ways.

"There were several signs that the Vikings had modified their teeth, including evidence of using toothpicks, filing front teeth, and even dental treatment of teeth with infections," says Carolina Bertilsson, a dentist and Associate Researcher, and the study's first-named and corresponding author.

Not unlike today's treatments

One sign of more sophisticated procedures was molars with filed holes, from the crown of the tooth and into the pulp, probably in order to relieve pressure and alleviate severe toothache due to infection.

"This is very exciting to see, and not unlike the dental treatments we carry out today when we drill into infected teeth. The Vikings seem to have had knowledge about teeth, but we don't know whether they did these procedures themselves or had help."

The filed front teeth may have been a form of identity marker.

In both this and previous studies, the cases found were male.

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What happens in the brain while daydreaming?

You are sitting quietly, and suddenly your brain tunes out the world and wanders to something else entirely -- perhaps a recent experience, or an old memory. You just had a daydream.

Yet despite the ubiquity of this experience, what is happening in the brain while daydreaming is a question that has largely eluded neuroscientists.

Now, a study in mice, published Dec. 13 in Nature, has brought a team led by researchers at Harvard Medical School one step closer to figuring it out.

The researchers tracked the activity of neurons in the visual cortex of the brains of mice while the animals remained in a quiet waking state. They found that occasionally these neurons fired in a pattern similar to one that occurred when a mouse looked at an actual image, suggesting that the mouse was thinking -- or daydreaming -- about the image. Moreover, the patterns of activity during a mouse's first few daydreams of the day predicted how the brain's response to the image would change over time.

The research provides tantalizing, if preliminary, evidence that daydreams can shape the brain's future response to what it sees. This causal relationship needs to be confirmed in further research, the team cautioned, but the results offer an intriguing clue that daydreams during quiet waking may play a role in brain plasticity -- the brain's ability to remodel itself in response to new experiences.

"We wanted to know how this daydreaming process occurred on a neurobiological level, and whether these moments of quiet reflection could be important for learning and memory," said lead author Nghia Nguyen, a PhD student in neurobiology in the Blavatnik Institute at HMS.

An overlooked brain region

Scientists have spent considerable time studying how neurons replay past events to form memories and map the physical environment in the hippocampus, a seahorse-shaped brain region that plays a key role in memory and spatial navigation.

By contrast, there has been little research on the replay of neurons in other brain regions, including the visual cortex. Such efforts would provide valuable insights about how visual memories are formed.

"My lab became interested in whether we could record from enough neurons in the visual cortex to understand what exactly the mouse is remembering -- and then connect that information to brain plasticity," said senior author Mark Andermann, professor of medicine at Beth Israel Deaconess Medical Center, and professor of neurobiology at HMS.

In the new study, the researchers repeatedly showed mice one of two images, each consisting of a different checkerboard pattern of gray and dappled black and white squares. Between images, the mice spent a minute looking at a gray screen. The team simultaneously recorded activity from around 7,000 neurons in the visual cortex.

The researchers found that when a mouse looked at an image, the neurons fired in a specific pattern, and the patterns were different enough to discern image one from image two. More important, when a mouse looked at the gray screen between images, the neurons sometimes fired in a similar, but not identical, pattern, as when the mouse looked at the image, a sign that it was daydreaming about the image. These daydreams occurred only when mice were relaxed, characterized by calm behavior and small pupils.

Unsurprisingly, mice daydreamed more about the most recent image -- and they had more daydreams at the beginning of the day than at the end, when they had already seen each image dozens of times.

But what the researchers found next was completely unexpected.

Throughout the day, and across days, the activity patterns seen when the mice looked at the images changed -- what neuroscientists call "representational drift." Yet this drift wasn't random. Over time, the patterns associated with the images became even more different from each other, until each involved an almost entirely separate set of neurons. Notably, the pattern seen during a mouse's first few daydreams about an image predicted what the pattern would become when the mouse looked at the image later.

"There's drift in how the brain responds to the same image over time, and these early daydreams can predict where the drift is going," Andermann said.

Finally, the researchers found that the visual cortex daydreams occurred at the same time as replay activity occurred in the hippocampus, suggesting that the two brain regions were communicating during these daydreams.

To sit, perchance to daydream

Based on the results of the study, the researchers suspect that these daydreams may be actively involved in brain plasticity.

"When you see two different images many times, it becomes important to discriminate between them. Our findings suggest that daydreaming may guide this process by steering the neural patterns associated with the two images away from each other," Nguyen said, while noting that this relationship needs to be confirmed.

Nguyen added that learning to differentiate between the images should help the mouse respond to each image with more specificity in the future.

These observations align with a growing body of evidence in rodents and humans that entering a state of quiet wakefulness after an experience can improve learning and memory.

Next, the researchers plan to use their imaging tools to visualize the connections between individual neurons in the visual cortex and to examine how these connections change when the brain "sees" an image.

"We were chasing this 99 percent of unexplored brain activity and discovered that there's so much richness in the visual cortex that nobody knew anything about," Andermann said.

Whether daydreams in people involve similar activity patterns in the visual cortex is an open question, and the answer will require additional experiments. However, there is preliminary evidence that an analogous process occurs in humans when they recall visual imagery.

Randy Buckner, the Sosland Family Professor of Psychology and of Neuroscience at Harvard University, has shown that brain activity in the visual cortex increases when people are asked to recall an image in detail. Other studies have recorded flurries of electrical activity in the visual cortex and the hippocampus during such recall.

For the researchers, the results of their study and others suggest that it may be important to make space for moments of quiet waking that lead to daydreams. For a mouse, this may mean taking a pause from looking at a series of images and, for a human, this could mean taking a break from scrolling on a smartphone.

"We feel pretty confident that if you never give yourself any awake downtime, you're not going to have as many of these daydream events, which may be important for brain plasticity," Andermann said.

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Some icy exoplanets may have habitable oceans and geysers

A NASA study expands the search for life beyond our solar system by indicating that 17 exoplanets (worlds outside our solar system) could have oceans of liquid water, an essential ingredient for life, beneath icy shells. Water from these oceans could occasionally erupt through the ice crust as geysers. The science team calculated the amount of geyser activity on these exoplanets, the first time these estimates have been made. They identified two exoplanets sufficiently close where signs of these eruptions could be observed with telescopes.

The search for life elsewhere in the Universe typically focuses on exoplanets that are in a star's "habitable zone," a distance where temperatures allow liquid water to persist on their surfaces. However, it's possible for an exoplanet that's too distant and cold to still have an ocean underneath an ice crust if it has enough internal heating. Such is the case in our solar system where Europa, a moon of Jupiter, and Enceladus, a moon of Saturn, have subsurface oceans because they are heated by tides from the gravitational pull of the host planet and neighboring moons.

These subsurface oceans could harbor life if they have other necessities, such as an energy supply as well as elements and compounds used in biological molecules. On Earth, entire ecosystems thrive in complete darkness at the bottom of oceans near hydrothermal vents, which provide energy and nutrients.

"Our analyses predict that these 17 worlds may have ice-covered surfaces but receive enough internal heating from the decay of radioactive elements and tidal forces from their host stars to maintain internal oceans," said Dr. Lynnae Quick of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Thanks to the amount of internal heating they experience, all planets in our study could also exhibit cryovolcanic eruptions in the form of geyser-like plumes." Quick is lead author of a paper on the research published on October 4 in the Astrophysical Journal.

The team considered conditions on 17 confirmed exoplanets that are roughly Earth-sized but less dense, suggesting that they could have substantial amounts of ice and water instead of denser rock. Although the planets' exact compositions remain unknown, initial estimates of their surface temperatures from previous studies all indicate that they are much colder than Earth, suggesting that their surfaces could be covered in ice.

The study improved estimates of each exoplanet's surface temperature by recalculating using the known surface brightness and other properties of Europa and Enceladus as models. The team also estimated the total internal heating in these exoplanets by using the shape of each exoplanet's orbit to get the heat generated from tides and adding it to the heat expected from radioactive activity. Surface temperature and total heating estimates gave the ice layer thickness for each exoplanet since the oceans cool and freeze at the surface while being heated from the interior. Finally, they compared these figures to Europa's and used estimated levels of geyser activity on Europa as a conservative baseline to estimate geyser activity on the exoplanets.

They predict that surface temperatures are colder than previous estimates by up to 60 degrees Fahrenheit (16 degrees Celsius). Estimated ice shell thickness ranged from about 190 feet (58 meters) for Proxima Centauri b and one mile (1.6 kilometers) for LHS 1140 b to 24 miles (38.6 kilometers) for MOA 2007 BLG 192Lb, compared to Europa's estimated average of 18 miles (almost 29 kilometers). Estimated geyser activity went from just 17.6 pounds per second (about 8 kilograms/second) for Kepler 441b to 639,640 pounds/second (290,000 kilograms/second) for LHS 1140b and 13.2 million pounds/second (six million kilograms/second) for Proxima Centauri b, compared to Europa at 4,400 pounds/second (2,000 kilograms/second).

"Since our models predict that oceans could be found relatively close to the surfaces of Proxima Centauri b and LHS 1140 b, and their rate of geyser activity could exceed Europa's by hundreds to thousands of times, telescopes are most likely to detect geological activity on these planets," said Quick, who is presenting this research December 12at the American Geophysical Union meeting in San Francisco, California.

This activity could be seen when the exoplanet passes in front of its star. Certain colors of starlight could be dimmed or blocked by water vapor from the geysers. "Sporadic detections of water vapor in which the amount of water vapor detected varies with time, would suggest the presence of cryovolcanic eruptions," said Quick. The water might contain other elements and compounds that could reveal if it can support life. Since elements and compounds absorb light at specific "signature" colors, analysis of the starlight would let scientists determine the geyser's composition and evaluate the exoplanet's habitability potential.

For planets like Proxima Centauri b that don't cross their stars from our vantage point, geyser activity could be detected by powerful telescopes that are able to measure light that the exoplanet reflects while orbiting its star. Geysers would expel icy particles at the exoplanet's surface which would cause the exoplanet to appear very bright and reflective.

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Twenty-year study confirms California forests are healthier when burned -- or thinned

A 20-year experiment in the Sierra Nevada confirms that different forest management techniques -- prescribed burning, restoration thinning or a combination of both -- are effective at reducing the risk of catastrophic wildfire in California.

These treatments also improve forest health, making trees more resilient to stressors like drought and bark beetles, and they do not negatively impact plant or wildlife biodiversity within individual tree stands, the research found. The findings of the experiment, called the Fire Surrogate Study, were published today in the journal Ecological Applications.

"The research is pretty darn clear that these treatments are effective -- very effective," said study lead author Scott Stephens, a professor of fire science at the University of California, Berkeley."I hope this lets people know that there is great hope in doing these treatments at scale, without any negative consequences."

Last year, California announced a strategic plan for expanding the use of prescribed fire to 400,000 acres annually by 2025. However, the use of beneficial fire continues to be hindered by multiple factors, including the lack of a trained workforce, the need for specific weather conditions for burning, and fears about potential risks.

This study shows that restoration thinning is also a viable option for forest management and can be used in tandem with beneficial fire without harming forest health or biodiversity.

"Our findings show that there's not just one solution -- there are multiple things that you can do to impact the risk of catastrophic fire," said study co-author Ariel Roughton, research station manager at Berkeley Forests. "Folks can choose from different combinations of treatments that might fit their needs, and we can show them how those treatments might impact things like wildfire behavior, tree growth and carbon holding in their forests."

Surrogates to wildfire

Over the past two decades, Stephens and other researchers at Berkeley Forests have used prescribed burning, restoration thinning or a combination of both to treat plots of land at Blodgett Forest Research Station, a 4,000-acre experimental forest located about 65 miles northeast of Sacramento on the unceded lands of the Nisenan peoples.

The Fire Surrogate Study was one of 13 studies across the U.S. first launched in 1999 with funding from the U.S. Joint Fire Science Program. Its aim was to study whether the two treatments could mimic the beneficial impacts of lightning fires and Indigenous burning practices on California's forests, which have become dense and overgrown after a century of logging and fire suppression.

"Prescribed fire and restoration thinning are both surrogates for wildfire, a key process that happened frequently in California before European colonization," Stephens said. "The impetus of this study was: If you're going to implement these treatments at a large scale, is there anything that's going to be lost?"

The study created nine experimental plots and three control plots at Blodgett. Three of the experimental plots were managed only using prescribed burns; three burns occurred over the course of 20 years. Three other experimental plots were first thinned and then burned, and the final three were treated only with restoration thinning. The control plots were left to grow without human interference except continued fire suppression.

At the end of the 20-year period, the researchers surveyed the vegetation in each plot and used computational modeling to estimate how many trees were likely to survive wildfire. They found that all three types of experimental plots were significantly more resilient to wildfire than the control plots, showing an 80% likelihood that at least 80% of trees would survive.

They also calculated the "index of competition," a measure of how strongly trees must compete for resources like sunlight, water and soil nutrients. By removing excess trees and vegetation, thinning and burning both limited the amount of competition between trees, making them less vulnerable to stressors, like drought and bark beetles.

However, the plots that were treated with a combination of thinning and fire had the best index of competition, suggesting that they would be the most resilient to the impacts of climate change.

"When you combine thinning with fire, you're able to modify all different levels of the forest structure,and it speeds up the timeline for achieving a more resilient structure," Roughton said.

Restoration thinning can also provide financial benefits: Often, larger trees can be sold to sawmills, and the proceeds can be used to help offset the cost of forest management. Over the course of 20 years, the treatments at Blodgett were entirely paid for by revenue from timber.

"When I go to Sacramento and talk about [forest management] with legislators, the first question they always ask is about cost," Stephens said. "People in the state government are telling us that they can't be the sole source support for this work. That's why the economicsare so important."

Trial by fire

In September 2022, the forests at Blodgett were subjected to a real-life test: On the morning of Sept. 9, 2022, the Mosquito Fire breached the north side of the property, burning approximately 300 acres before it was contained two days later.

One of the study's control plots was located directly in the path of the blaze, and more than 60% of the trees in this plot were completely scorched. However, neighboring experimental plots that had been treated with prescribed burns served as "fuel breaks," burning less hot than the control and acting as staging areas for firefighters.

"We think that, overall, our management actions, coupled with the weather, did have a pretty big impact on the behavior of the fire," Roughton said.

The researchers have received a four-year grant from the Joint Fire Science Program to continue the Fire Surrogate Project. With the help of the grant, they have established a new control plot to replace the one that burned and plan to apply a fourth fire to the experimental burn-only plots.

They are also collaborating with the United Auburn Indian Community to reestablish Indigenous cultural burning at Blodgett.

"We want to be part of the solution, and that's part of our mission at Blodgett," Roughton said. "We hope that by doing these studies and bringing folks here to see the effects of the different treatments, they will take that back and apply it to the land that they're going to be managing."

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Ultra-hard material to rival diamond discovered

Scientists have solved a decades-long puzzle and unveiled a near unbreakable substance that could rival diamond, as the hardest material on earth, a study says.

Researchers found that when carbon and nitrogen precursors were subjected to extreme heat and pressure, the resulting materials -- known as carbon nitrides -- were tougher than cubic boron nitride, the second hardest material after diamond.

The breakthrough opens doors for multifunctional materials to be used for industrial purposes including protective coatings for cars and spaceships, high-endurance cutting tools, solar panels and photodetectors, experts say.

Materials researchers have attempted to unlock the potential of carbon nitrides since the 1980s, when scientists first noticed their exceptional properties, including high resistance to heat.

Yet after more than three decades of research and multiple attempts to synthesize them, no credible results were reported.

Now, an international team of scientists -- led by researchers from the Centre for Science at Extreme Conditions at the University of Edinburgh and experts from the University of Bayreuth, Germany and the University of Linköping, Sweden -- have finally achieved a breakthrough.

The team subjected various forms of carbon nitrogen precursors to pressures of between 70 and 135 gigapascals -- around one million times our atmospheric pressure -- while heating it to temperatures of more than one and a half thousand degrees celsius.

To identify the atomic arrangement of thecompounds under these conditions, the samples were illuminated by an intense X-ray beam at three particle accelerators -- the European Synchrotron Research Facility in France, the Deutsches Elektronen-Synchrotron in Germany and the Advanced Photon Source based in the United States.

Researchers discovered that three carbon nitride compounds were found to have the necessary building blocks for super-hardness.

Remarkably, all three compounds retained their diamond-like qualities when they returned to ambient pressure and temperature conditions.

Further calculations and experiments suggest the new materials contain additional properties including photoluminescence and high energy density, where a large amount of energy can be stored in a small amount of mass.

Researchers say the potential applications of these ultra-incompressible carbon nitrides is vast, potentially positioning them as ultimate engineering materials to rival diamonds.

The research, published in Advanced Materials, was funded by the UKRI FLF scheme and European research grants.

Dr Dominique Laniel, Future Leaders Fellow, Institute for Condensed Matter Physics and Complex Systems, School of Physics and Astronomy, University of Edinburgh, said: "Upon the discovery of the first of these new carbon nitride materials, we were incredulous to have produced materials researchers have been dreaming of for the last three decades. These materials provide strong incentive to bridge the gap between high pressure materials synthesis and industrial applications."

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Scientists unveil complete cell map of a whole mammalian brain

For the first time ever, an international team of researchers has created a complete cell atlas of a whole mammalian brain. This atlas serves as a map for the mouse brain, describing the type, location, and molecular information of more than 32 million cells and providing information on connectivity between these cells. The mouse is the most commonly used vertebrate experimental model in neuroscience research, and this cellular map paves the way for a greater understanding of the human brain -- arguably the most powerful computer in the world. The cell atlas also lays the foundation for the development of a new generation of precision therapeutics for people with mental and neurological disorders of the brain.

The findings were funded by the National Institutes of Health's Brain Research Through Advancing Innovative Neurotechnologies® Initiative, or The BRAIN Initiative®, and appear in a collection of 10 papers published in Nature.

"The mouse atlas has brought the intricate network of mammalian brain cells into unprecedented focus, giving researchers the details needed to understand human brain function and diseases," said Joshua A. Gordon, M.D., Ph.D., Director of the National Institute of Mental Health, part of the National Institutes of Health.

The cell atlas describes the types of cells in each region of the mouse brain and their organization within those regions.

In addition to this structural information, the cell atlas provides an incredibly detailed catalog of the cell's transcriptome -- the complete set of gene readouts in a cell, which contains instructions for making proteins and other cellular products.

The transcriptomic information included in the atlas is hierarchically organized, detailing cell classes, subclasses, and thousands of individual cell clusters within the brain.

The atlas also characterizes the cell epigenome -- chemical modifications to a cell's DNA and chromosomes that alter the way the cell's genetic information is expressed -- detailing thousands of epigenomic cell types and millions of candidate genetic regulation elements for different brain cell types.

Together, the structural, transcriptomic, and epigenetic information included in this atlas provide an unprecedented map of cellular organization and diversity across the mouse brain.

The atlas also provides an accounting of the neurotransmitters and neuropeptides used by different cells and the relationship among cell types within the brain.

This information can be used as a detailed blueprint for how chemical signals are initiated and transmitted in different parts of the brain.

Those electrical signals are the basis for how brain circuits operate and how the brain functions overall.

"This product is a testament to the power of this unprecedented, cross-cutting collaboration and paves our path for more precision brain treatments," said John Ngai, Ph.D., Director of the NIH BRAIN Initiative."

Of the 10 studies included in this collection, seven are funded through the NIH BRAIN Initiative Cell Census Network (BICCN), and two are funded through the larger NIH BRAIN Initiative.

The core aim of the BICCN, a groundbreaking, cross-collaborative effort to understand the brain's cellular makeup, is to develop a comprehensive inventory of the cells in the brain -- where they are, how they develop, how they work together, and how they regulate their activity -- to better understand how brain disorders develop, progress, and are best treated.

"By leveraging the unique nature of its multi-disciplinary and international collaboration, the BICCN was able to accomplish what no other team of scientists has been able to before," said Dr. Ngai.

"Now we are ready to take the next big step -- completing the cell maps of the human brain and the nonhuman primate brain."

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Ryugu samples illuminate terrestrial weathering effects on primitive meteorites

A groundbreaking study conducted by a team of international scientists has unveiled unprecedented insights into the nature of the asteroid Ryugu and shed light on the composition of water- and carbon-rich small bodies in the solar system.

Asteroids like Ryugu are remnants of planetary embryos that never reached larger sizes, making them invaluable windows into materials that formed in the early solar system.

The study centered on laboratory measurements of the samples brought back to the Earth by the Hayabusa2 spacecraft in 2020.

Led by the Japan Aerospace Exploration Agency (JAXA), Hayabusa2 aimed to uncover the true nature of Ryugu and explore how astrologists can use knowledge from meteorites to interpret telescopic observations of other hydrous asteroids.

Unlike meteorites derived from similar hydrous asteroids, the Ryugu samples avoided terrestrial alteration -- the interaction with oxygen and water in the Earth's atmosphere.

Reflectance spectroscopy, a primary technique linking laboratory analyses of meteorites to asteroid observations, was employed to compare fresh Ryugu samples with meteorites altered in terrestrial environments.

The team successfully developed analytical procedures that avoided exposing the samples to Earth's atmosphere, ensuring the preservation of their original conditions.

Previous studies suggested that Ryugu's sample mineralogy resembled CI chondrites, the most primitive meteorites chemically.

However, other studies have contradicted this by revealing a significant difference in reflectance spectra between Ryugu samples and CI chondrites.

Further investigations in the new study indicated that heating CI samples under reducing conditions at 300 °C reproduced Ryugu's sample mineralogy well, resulting in spectra closely matching those of Ryugu samples.

The findings challenge previous assumptions about the parent bodies of CI chondrites and underscore the susceptibility of primitive meteorite spectra to terrestrial weathering.

The study suggests that actual CI chondrite parent bodies likely exhibit darker and flatter reflectance spectra than previously thought.

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Alaskan allies: Communities unite to protect the areas they love

Natural resource management decisions in protected areas impact more than the wildlife and landscapes they're charged to conserve. They also affect neighbors, who could otherwise hunt, build, or recreate as they choose on their own land. For decades, community members primarily voiced their opinions through brief and impersonal public comment periods. But an initiative led by environmental social scientists at the University of Illinois Urbana-Champaign is putting a new spin on neighborly communication.

"Historically, public land management agencies would offer brief periods where people could submit a remark that may or may not be considered and that typically wouldn't result in any meaningful dialogue," said Carena van Riper, associate professor in the Department of Natural Resources and Environmental Sciences in the College of Agricultural, Consumer and Environmental Sciences (ACES) at U. of I. "For more inclusive conservation to happen, there needs to be in-depth engagement, communication, and deliberation with diverse stakeholders. There's real benefit to engaging people."

Van Riper has been working toward a model of inclusive conservation for nearly a decade in the area surrounding Alaska's Denali National Park, partnering with the National Park System (NPS) to examine the values and viewpoints of neighbors on everything from conservation priorities to tourism impacts. She and her colleagues published results of their latest engagement efforts in Sustainability Science.

The study brought Denali neighbors together in a month-long online discussion forum designed to understand their views on the benefits and threats facing the area, as well as how land management agencies could better incorporate their perspectives.

Van Riper noted that residents come from all walks of life and have priorities that span protected area conservation, indigenous use, tourism, energy development, and others.

"Although it is important, conservation is just one of many priorities," she said. "We tried to equalize the power dynamic among interest groups and in how we framed the National Park Service and its role in defining life in Interior Alaska."

Residents were grouped according to a values assessment, with two groups of like-minded participants and one group representing a mix of values. This allowed the research team to test whether the value-basis of decision-making affected the ways that people learned from one another and engaged in collaborative dialogue.

"I went into this project worried because a lot of online dialogue tends to be very combative. But the most wonderful discussions unfolded with this group of people; they were always thoughtful and respectful to one another. They disagreed, but we never had to step in and intervene," said lead author Devin Goodson, a doctoral student working with van Riper. "Another one of the benefits of engaging online is people weren't forced to fully explain their thoughts in the moment, like you'd have to do during a short public comment session. The platform created a really well informed and constructive conversation."

After a period where participants got to know each other during focus groups, they were engaged through the Denali Discussion Forum, where the researchers posed a series of questions about the park and its management. Residents were expected to answer the questions and interact with other participants' answers on a weekly basis during the month-long program.

Goodson said the residents discussed many of the same benefits of living near Denali, though the groups differed in the emphasis they placed on particular benefits, which included access to wilderness, solitude, recreation, hunting and fishing grounds, and the pursuit of a subsistence lifestyle. Likewise, the groups emphasized slightly different threats, including tourism, competing interests, mismanagement, and climate change -- the latter was mentioned only by the mixed values group, which comprised a younger demographic. The groups diverged more strongly in their discussions on management solutions.

"We found that residents value the Alaskan landscape in a lot of ways and often identify common threats, but they come up with different ways to solve these issues. However, a common thread across the proposed solutions for resource managers was that people just wanted to feel like they were a part of the process in a meaningful way," Goodson said. "They're open to what that looks like, but they want to feel that the process overall is fair."

Co-author William Stewart in the Department of Recreation, Sport and Tourism at U. of I. added, "The NPS makes well-intentioned decisions, yet sometimes, residents of nearby communities feel like their voices aren't being heard. They need help. Social scientists have a toolkit for that. We engage community residents not as decision-makers, but as outsiders who could represent community voices to help facilitate dialogue with the park, and within the park service."

Armed with results from the Denali Discussion Forum, which were summarized weekly by the study team with input from participants, NPS can move ahead with more informed management decisions. And they can use a similar model to solicit input for future management actions.

But the lessons extend well beyond Denali and even the National Park System. Goodson said the study is an example of one way to give average people a say in the things that impact them every day in their environment.

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This Japanese 'dragon' terrorized ancient seas

Researchers have described a Japanese mosasaur the size of a great white shark that terrorized Pacific seas 72 million years ago.

Extra-long rear flippers might have aided propulsion in concert with its long finned tail.

And unlike other mosasaurs, or large extinct marine reptiles, it had a dorsal fin like a shark's that would have helped it turn quickly and with precision in the water.

University of Cincinnati Associate Professor Takuya Konishi and his international co-authors described the mosasaur and placed it in a taxonomic context in the Journal of Systematic Palaeontology.

The mosasaur was named for the place where it was found, Wakayama Prefecture.

Researchers call it the Wakayama Soryu, which means blue dragon.

Dragons are creatures of legend in Japanese folklore, Konishi said.

"In China, dragons make thunder and live in the sky. They became aquatic in Japanese mythology," he said.

The specimen was discovered along the Aridagawa River in Wakayama by co-author Akihiro Misaki in 2006.

The specimen is the most complete skeleton of a mosasaur ever found in Japan or the northwestern Pacific, Konishi said.

"In this case, it was nearly the entire specimen, which was astounding," Konishi said.

He has dedicated his career to studying these ancient marine reptiles.

But the Japanese specimen has unique features that defies simple classification, he said.

Its rear flippers are longer than its front ones. These enormous flippers are even longer than its crocodile-like head, which is unique among mosasaurs.

"I thought I knew them quite well by now," Konishi said. "Immediately it was something I had never seen before."

Mosasaurs were apex predators in prehistoric oceans from about 100 million years ago to 66 million years ago.

They were contemporaries of Tyrannosaurus rex and other late Cretaceous dinosaurs that ruled the Earth.

Mosasaurs were victims of the same mass extinction that killed off nearly all dinosaurs when an asteroid struck what is now the Gulf of Mexico.

Researchers placed the specimen in the subfamily Mosasaurinae and named it Megapterygius wakayamaensis to recognize where it was found.

Megapterygius means "large winged" in keeping with the mosasaur's enormous flippers.

Konishi said those big paddle-shaped flippers might have been used for locomotion.

But that type of swimming would be extraordinary not only among mosasaurs but among virtually all other animals.

"We lack any modern analog that has this kind of body morphology -- from fish to penguins to sea turtles," he said.

"None has four large flippers they use in conjunction with a tail fin."

Researchers speculated that the large front fins might have helped with rapid maneuvering while its large rear fins might have provided pitch to dive or surface.

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Archaeologists unearth one of earliest known frame saddles

In April 2015, looters sacked an ancient cave burial at a site called Urd Ulaan Uneet high within the Altai Mountains of western Mongolia. When police apprehended the criminals, they uncovered, among other artifacts, an elegantly carved saddle made from several pieces of birch wood.

Now, in a new study, researchers from Mongolia collaborating with University of Colorado Boulder archaeologist William Taylor have described the find. The team's radiocarbon dating pins the artifact to roughly the 4th Century C.E., making it one of the earliest known frame saddles in the world.

"It was a watershed moment in the technological history of people and horses," said Taylor, corresponding author of the new study and curator of archaeology at the CU Museum of Natural History.

He and his colleagues, including scientists from 10 countries, published their findings Dec. 12 in the journal Antiquity.

The research reveals the underappreciated role that ancient Mongolians played in the spread of horse riding technology and culture around the globe. Those advances ushered in a new and sometimes brutal era of mounted warfare around the same time as the fall of the Roman Empire.

The discovery also highlights the deep relationships between human and animals in Mongolia. For millennia, pastoral peoples have traveled between the vast grasslands of the Mongolian Steppe with their horses -- which, in the region, tend to be short but sturdy, capable of surviving winter temperatures that can plummet far below freezing. Airag, a lightly alcoholic beverage made from fermented horse milk, remains a popular libation in Mongolia.

"Ultimately, technology emerging from Mongolia has, through a domino effect, ended up shaping the horse culture that we have in America today, especially our traditions of saddlery and stirrups," Taylor said.

But these insights also come at a time when Mongolia's horse culture is beginning to disappear, said study lead author Jamsranjav Bayarsaikhan.

"Horses have not only influenced the history of the region but also left a deep mark on the art and worldview of the Nomadic Mongols," said Bayarsaikhan, an archaeologist at the Max Planck Institute for the Science of Human History in Germany. "However, the age of technology is slowly erasing the culture and use of horses. Instead of herders riding horses, more and more people are riding motorcycles in the plains of Mongolia."

Mounted combat

Bayarsaikhan was working as a curator at the National Museum of Mongolia when he and his colleagues got the call from police in Hovd Province. The team later excavated the Urd Ulaan Uneet cave and unearthed the mummified remains of a horse, which the group partially described in a 2018 paper.

The saddle itself was made from about six pieces of birch wood held together with wooden nails. It bears traces of red paint with black trim and includes two leather straps that likely once supported stirrups. (The researchers also reported an iron stirrup recently discovered from around the same time period in eastern Mongolia).

The group couldn't definitively trace back where those materials came from. Birch trees, however, grow commonly in the Mongolian Altai, suggesting that locals had crafted the saddle themselves, not traded for it.

Taylor explained that humans had used pads, a form of proto-saddle, to keep their rear ends comfortable on horseback since the earliest days of mounted riding. Rigid wooden saddles, which were much sturdier, paired with stirrups opened a new range of things that people could do with horses.

"One thing they very gave rise to was heavy cavalry and high-impact combat on horseback," Taylor said. "Think of jousting in Medieval Europe."

Traveling west

In the centuries after the Mongolian saddle was crafted, these types of tools spread rapidly west across Asia and into the early Islamic world. There, cavalry forces became key to conquest and trade across large portions of the Mediterranean region and northern Africa.

Where it all began, however, is less clear. Archaeologists have typically considered modern-day China the birthplace of the first frame saddles and stirrups -- with some finds dating back to the 5th to 6th Century C.E. or even earlier.

The new study, however, complicates that picture, Taylor said.

"It's not the only piece of information suggesting that Mongolia might have been either among the very first adopters of these new technologies -- or could, in fact, be the place where they were first innovated," he said.

He suspects that Mongolia's place in that history may have gone underappreciated for so long in part because of the region's geography. The population density in the country's mountainous expanses is low, among the lowest on Earth, making it difficult to encounter and analyze important archaeological finds.

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When is an aurora not an aurora?

The shimmering green, red and purple curtains of the northern and southern lights -- the auroras -- may be the best-known phenomena lighting up the nighttime sky, but the most mysterious are the mauve and white streaks called Steve and their frequent companion, a glowing green "picket fence."

First recognized in 2018 as distinct from the common auroras, Steve -- a tongue-in-cheek reference to the benign name given a scary hedge in a 2006 children's movie -- and its associated picket fence were nevertheless thought to be caused by the same physical processes. But scientists were left scratching their heads about how these glowing emissions were produced.

Claire Gasque, a University of California, Berkeley, graduate student in physics, has now proposed a physical explanation for these phenomena that is totally different from the processes responsible for the well-known auroras. She has teamed up with researchers at the campus's Space Sciences Laboratory (SSL) to propose that NASA launch a rocket into the heart of the aurora to find out if she's correct.

Vibrant auroras and glowing phenomena such as Steve and the picket fence are becoming more common as the sun enters the active period of its 11-year cycle, and November was a good month for Steve observations in the northern latitudes. Because all these transient luminous phenomena are triggered by solar storms and coronal mass ejections from the sun, the approaching solar maximum is an ideal time to study rare events like Steve and the picket fence.

Gasque described the physics behind the picket fence in a paper published last month in the journal Geophysical Research Letters and will discuss the results on Dec. 14 in an invited talk at the American Geophysical Union meeting in San Francisco.

She calculated that in a region of the upper atmosphere farther south than that in which auroras form, electric fields parallel to Earth's magnetic field could produce the color spectrum of the picket fence. If correct, this unusual process has implications for how physicists understand energy flow between Earth's magnetosphere, which surrounds and protects Earth from the solar wind, and the ionosphere at the edge of space.

"This would upend our modeling of what creates light and the energy in the aurora in some cases," Gasque said.

"The really interesting thing about Claire's paper is that we've known for a couple of years now that the Steve spectrum is telling us there's some very exotic physics going on. We just didn't know what it was," said Brian Harding, a co-author of the paper and an SSL assistant research physicist. "Claire's paper showed that parallel electric fields are capable of explaining this exotic spectrum."

The paper was a side project from Gasque's Ph.D. thesis, which is focused on the connection between events like volcanoes on Earth's surface and phenomena in the ionosphere 100 kilometers or more above our heads.

But after hearing about Steve -- which has now become an acronym for Strong Thermal Emission Velocity Enhancement -- at a conference in 2022, she couldn't resist looking into the physics behind Steve and the picket fence.

"It's really cool," she said. "It's one of the biggest mysteries in space physics right now."

The physics of Steve and picket fence

The common auroras are produced when the solar wind energizes particles in Earth's magnetosphere, often at altitudes higher than 1,000 kilometers above the surface. These energized particles spiral around Earth's magnetic field lines toward the poles, where they crash into and excite oxygen and nitrogen molecules in the upper atmosphere. When those molecules relax, oxygen emits specific frequencies of green and red light, while nitrogen generates a bit of red, but primarily a blue, emission line.

The colorful, shimmering curtains that result can extend for thousands of kilometers across the northern or southern latitudes.

Steve, however, displays not individual emission lines, but a broad range of frequencies centered around purple or mauve. And unlike auroras, neither Steve nor the picket fence emit blue light, which is generated when the most energetic particles hit and ionize nitrogen. Steve and the picket fence also occur at lower latitudes than the aurora, potentially even as far south as the equator.

Some researchers proposed that Steve is caused by ion flows in the upper atmosphere, referred to as subauroral ion drift, or SAID, though there's no well accepted physical explanation for how SAID could generate the colorful emissions.

Gasque's interest was sparked by suggestions that the picket fence's emissions could be generated by low-altitude electric fields parallel to Earth's magnetic field, a situation thought to be impossible because any electric field aligned with the magnetic field should quickly short out and disappear.

Using a common physical model of the ionosphere, Gasque subsequently showed that a moderate parallel electric field -- around 100 millivolts per meter -- at a height of about 110 km could accelerate electrons to an energy that would excite oxygen and nitrogen and generate the spectrum of light observed from the picket fence. Unusual conditions in that area, such as a lower density of charged plasma and more neutral atoms of oxygen and nitrogen, could potentially act as insulation to keep the electric field from shorting out.

"If you look at the spectrum of the picket fence, it's much more green than you would expect. And there's none of the blue that's coming from the ionization of nitrogen," Gasque said. "What that's telling us is that there's only a specific energy range of electrons that can create those colors, and they can't be coming from way out in space down into the atmosphere, because those particles have too much energy."

Instead, she said, "the light from the picket fence is being created by particles that have to be energized right there in space by a parallel electric field, which is a completely different mechanism than any of the aurora that we've studied or known before."

She and Harding suspect that Steve itself may be produced by related processes. Their calculations also predict the type of ultraviolet emissions that this process would produce, which can be checked to verify the new hypothesis about the picket fence.

Though Gasque's calculations don't directly address the on-off glow that makes the phenomenon look like a picket fence, it's likely due to wavelike variations in the electric field, she said. And while the particles that are accelerated by the electric field are probably not from the sun, the scrambling of the atmosphere by solar storms probably triggers Steve and the picket fence, as it does the common aurora.

Enhanced auroras exhibit a picket fence-like glow

The next step, Harding said, is to launch a rocket from Alaska through these phenomena and measure the strength and direction of the electric and magnetic fields. SSL scientists specialize in designing and building instruments that do just that. Many of these instruments are on spacecraft now orbiting Earth and the sun.

Initially, the target would be what's known as an enhanced aurora, which is a normal aurora with picket fence-like emissions embedded in it.

"The enhanced aurora is basically this bright layer that's embedded in the normal aurora. The colors are similar to the picket fence in that there's not as much blue in them, and there's more green from oxygen and red from nitrogen. The hypothesis is that these are also created by parallel electric fields, but they are a lot more common than the picket fence," Gasque said.

The plan is not only "to fly a rocket through that enhanced layer to actually measure those parallel electric fields for the first time," she said, but also send a second rocket up to measure the particles at higher altitudes, "to distinguish the conditions from those that cause the auroras." Eventually, she hopes for a rocket that will fly directly through Steve and the picket fence.

Harding, Gasque and colleagues proposed just such a sounding rocket campaign to NASA this fall and expect to hear back regarding its selection in the first half of 2024. Gasque and Harding consider the experiment an important step in understanding the chemistry and physics of the upper atmosphere, the ionosphere and Earth's magnetosphere, and a proposal in line with the Low Cost Access to Space (LCAS) program sponsored by NASA for projects like this.

"It's fair to say that there's going to be a lot of study in the future about how those electric fields got there, what waves they are or aren't associated with, and what that means for the larger energy transfer between Earth's atmosphere and space," Harding said. "We really don't know. Claire's paper is the first step in the chain of that understanding."

Gasque expressed appreciation for the input from people who study the middle ionosphere, or mesosphere, and the stratosphere, whose ideas helped her puzzle out the solution.

"With this collaboration, we were able to make some really cool progress in this field," she said. "Honestly, it was just following our nose and being excited about it."

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