A new biomaterial delivered to the heart soon after a heart attack can heal damaged tissue from the inside out.

Heart attacks kill cardiac muscle tissue, scarring the heart and leaving permanent damage after just six hours. The damage prevents the heart from functioning properly. If there was a way to begin healing damaged tissue soon after a heart attack, doctors could prevent scar tissue from developing.

“In an ideal world, you treat a patient immediately when they’re having a heart attack to try to salvage some of the tissue and promote regeneration,” says Karen Christman, a bioengineer at the University of California, San Diego.
The pursuit of this ideal inspired Christman, along with a team of researchers, to develop the biomaterial. In rodents and pigs, it appears to repair tissue damage and reduce inflammation directly after a heart attack, Christman and colleagues report December 29 in Nature Biomedical Engineering.

“I think it has a lot of potential,” Vimala Bharadwaj, a biomedical scientist at Stanford University who was not involved in the research. The paper “is definitely good proof of concept for what they’re trying to do.”

Previously, researchers found that stem cells derived from body fat can be used to heal bones, muscles and the heart (SN: 3/9/16). Christman wanted to work with the extracellular matrix, the lattice of proteins that provide structural support to the cells in cardiac muscle tissue. Like stems cells, it has regenerative abilities but is much less expensive, she says.

In 2009, Christman’s team produced a hydrogel using particles from this matrix. Trials in rats and later in humans showed that the material bonded to damaged areas and promoted cell repair and growth. However, due to relatively large particles of the hydrogel, it could be delivered to the heart only via a needle.

“Poking the heart with a needle could set off an arrhythmia,” says Christman. To use this treatment, doctors would need to wait a few weeks until the heart is more stable and the chance of these irregular heartbeats decreases. And that would be too late to prevent scarring.

The team took the previously created hydrogel, sifted out the larger particles with a centrifuge so only nanoparticles remained, and added water to dilute the mixture. That created a material thin enough to deliver to heart blood vessels intravenously.
Based on the nanoparticles’ size, the team expected the mixture would slip through any gaps in cardiac blood vessels caused by the heart attack and adhere to the surrounding tissue. Once there, it would create a protective barrier while the heart healed.

Instead, animal experiments showed that the extracellular matrix material bound to the leaky vessels, preventing some inflammatory cells from moving into the heart tissue in the first place and causing further damage. The material reduced inflammation in the heart and stimulated the healing process by encouraging cell growth, the team reports.

Further safety studies will be needed to get the biomaterial ready for clinical trials. The first trial in humans will most likely be for repairing cardiac tissue post–heart attack. “A lot of my motivation is moving things out of the lab, actually into the real world,” Christman says.

Another real-world application of the biomaterial could be treatment for leaky blood vessels in other hard-to-access organs, including in the brain after a traumatic injury, Christman notes.

While Bharadwaj finds that application potentially promising, she says tests are needed to see whether the biomaterial improves headaches and cognitive or memory deficits in the brain after a traumatic injury. That’s needed to gauge whether it really is an effective TBI treatment.

As early as 252 million years ago, some plants may have curled up their leaves at night for a cozy “sleep.”

Fossilized leaves of two now-extinct Gigantonoclea species bear signs of nyctinasty, or circadian rhythmic folding at night, researchers report February 15 in Current Biology. That would make these specimens the first known fossilized examples of this curious plant behavior, the team says.

The two leaf fossils were discovered in a rock layer in southwestern China that dates to between 259 million and 252 million years ago. In both species, the leaves were broad, with serrated edges. But most curiously, they bear oddly symmetrical holes.
Insects made those holes while feeding on the leaves while they were folded, say paleontologist Zhuo Feng of Yunnan University in Kunming, China and colleagues. Similar symmetrical patterns of insect damage in leaf fossils can be used to distinguish folding behavior from leaves that might have shriveled as the plant died, the team says.

Modern plants, including many in the legume family such as the orchid tree, that fold and unfold their leaves use specialized cells called pulvinus cells, which act somewhat like muscles (SN: 2/3/23). By shifting water from one part of the leaf to another, the cells can bloat or deflate, allowing the leaves to fold or curl.

These cells would be at the base of the leaves, which weren’t preserved in the fossils, so it’s not possible to say whether these ancient plants also had pulvinus cells, the team says. Although it’s also hard to prove this was nighttime behavior, the leaves would also have had to be folded long enough for insects to do their munching. But the find does suggest that such leaf folding emerged independently in different plant lineages: Nearly all the modern plants that do this are angiosperms, or flowering plants. But Gigantonoclea plants were gymnosperms, seed-producing plants such as conifers and ginkgos.

Antarctica’s most vulnerable climate hot spot is a remote and hostile place — a narrow sliver of seawater, beneath a slab of floating ice more than half a kilometer thick. Scientists have finally explored it, and uncovered something surprising.

“The melt rate is much weaker than we would have thought, given how warm the ocean is,” says Peter Davis, an oceanographer at the British Antarctic Survey in Cambridge who was part of the team that drilled a narrow hole into this nook and lowered instruments into it. The finding might seem like good news — but it isn’t, he says. “Despite those low melt rates, we’re still seeing rapid retreat” as the ice vanishes faster than it’s being replenished.
Davis and about 20 other scientists conducted this research at Thwaites Glacier, a massive conveyor belt of ice about 120 kilometers wide, which flows off the coastline of West Antarctica. Satellite measurements show that Thwaites is losing ice more quickly than at any time in the last few thousand years (SN: 6/9/22). It has accelerated its flow into the ocean by at least 30 percent since 2000, hemorrhaging over 1,000 cubic kilometers of ice — accounting for roughly half of the ice lost from all of Antarctica.

Much of the current ice loss is driven by warm, salty ocean currents that are destabilizing the glacier at its grounding zone — the crucial foothold, about 500 meters below sea level at the drilling location, where the ice lifts off its bed and floats (SN: 4/9/21).

Now, this first-ever look at the glacier’s underbelly near the grounding zone shows that the ocean is attacking it in previously unknown and troubling ways.
When the researchers sent a remote-operated vehicle, or ROV, down the borehole and into the water below, they found that much of the melting is concentrated in places where the glacier is already under mechanical stress — within massive cracks called basal crevasses. These openings slice up into the underside of the ice.

Even a small amount of melting at these weak spots could inflict a disproportionately large amount of structural damage on the glacier, the researchers report in two papers published February 15 in Nature.

These results are “a bit of a surprise,” says Ted Scambos, a glaciologist at the University of Colorado Boulder who was not part of the team. Thwaites and other glaciers are monitored mostly with satellites, which make it appear that thinning and melting happen uniformly under the ice.

As the world continues to warm due to human-caused climate change, the shrinking glacier itself has the potential to raise global sea level by 65 centimeters over a period of centuries. Its collapse would also destabilize the remainder of the West Antarctic Ice Sheet, triggering an eventual three meters of global sea level rise.

With these new results, Scambos says, “we’re seeing in much more detail processes that will be important for modeling” how the glacier responds to future warming, and how quickly sea level will rise.

A cold, thin layer shields parts of Thwaites Glacier’s underside
Simply getting these observations “is kind of like a moon shot, or even a Mars shot,” Scambos says. Thwaites, like most of the West Antarctic Ice Sheet, rests on a bed that is hundreds of meters below sea level. The floating front of the glacier, called an ice shelf, extends 15 kilometers out onto the ocean, creating a roof of ice that makes this spot almost entirely inaccessible to humans. “This might represent the pinnacle of exploration” in Antarctica, he says.

These new results stem from a $50 million effort — the International Thwaites Glacier Collaboration — conducted by the United States’ National Science Foundation and United Kingdom’s Natural Environment Research Council. The research team, one of eight funded by that collaboration, landed on the snowy, flat expanse of Thwaites in the final days of 2019.

The researchers used a hot water drill to melt a narrow hole, not much wider than a basketball, through more than 500 meters of ice. Below the ice sat a water column that was only 54 meters thick.

When Davis and his colleagues measured the temperature and salinity of that water, they found that most of it was about 2 degrees Celsius above freezing — potentially warm enough to melt 20 to 40 meters of ice per year. But the underside of the ice seems to be melting at a rate of only 5 meters per year, researchers report in one of the Nature papers. The team calculated the melt rate based on the water’s salinity, which reveals the ratio of seawater, which is salty, to glacial meltwater, which is fresh.

The reason for that slow melt quickly emerged: Just beneath the ice sat a layer of cold, buoyant water, only 2 meters thick, derived from melted ice. “There is pooling of much fresher water at the ice base,” says Davis, and this cold layer shields the ice from warmer water below.

Those measurements provided a snapshot right at the borehole. Several days after the hole was opened, the researchers began a broader exploration of the unmapped ocean cavity under the ice.

Workers winched a skinny, yellow and black cylinder down the borehole. This ROV, called Icefin, was developed over the last seven years by a team of engineers led by Britney Schmidt, a glaciologist at Cornell University.
Schmidt and her team piloted the craft from a nearby tent, monitoring instruments while she steered the craft with gentle nudges to the buttons of a PlayStation 4 controller. The smooth, mirrorlike ceiling of ice scrolled silently past on a computer monitor — the live video feed piped up through 3½ kilometers of fiber-optic cable.

As Schmidt guided Icefin about 1.6 kilometers upstream from the borehole, the water column gradually tapered, until less than a meter of water separated the ice from the seafloor below. A few fish and shrimplike crustaceans called amphipods flitted among otherwise barren piles of gravel.

This new section of seafloor — revealed as the ice thins, lifts and floats progressively farther inland — had been exposed “for less than a year,” Schmidt says.

Now and then, Icefin skimmed past a dark, gaping cleft in the icy ceiling, a basal crevasse. Schmidt steered the craft into several of these gaps — often over 100 meters wide — and there, she saw something striking.

Melting of Thwaites’ underbelly is concentrated in deep crevasses
The vertical walls of the crevasses were scalloped rather than smooth, suggesting a higher rate of melting than that of the flat icy ceiling. And in these places, the video became blurry as the light refracted through vigorously swirling eddies of salty water and freshwater. That turbulent swirling of warm ocean water and cold meltwater is breaking up the cold layer that insulates the ice, pulling warm, salty water into contact with it, the scientists think.

Schmidt’s team calculated that the walls of the crevasses are melting at rates of up to 43 meters per year, the researchers report in the second Nature paper. The researchers also found rapid melt in other places where the level ceiling of ice is punctuated by short, steep sections.

The greater turbulence and higher melt also appear driven by ocean currents within the crevasses. Each time Schmidt steered Icefin up into a crevasse, the ROV detected streams of water flowing through it, as though the crevasse were an upside-down ditch. These currents moved up to twice as fast as the currents outside of crevasses.

The fact that melting is concentrated in crevasses has huge implications, says Peter Washam, an oceanographer on Schmidt’s team at Cornell: “The ocean is widening these features by melting them faster.”

This could greatly accelerate the years-long process by which some of these cracks propagate hundreds of meters up through the ice until they break through at the top — calving off an iceberg that drifts away. It could cause the floating ice shelf, which presses against an undersea mountain and buttresses the ice behind it, to break apart more quickly than predicted. This, in turn, could cause the glacier to spill ice into the ocean more quickly (SN: 12/13/21). “It’s going to have an impact on the stability of the ice,” Washam says.
These new data will improve scientists’ ability to predict the future retreat of Thwaites and other Antarctic glaciers, says Eric Rignot, a glaciologist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., who assisted the team by providing satellite measurements of changes in the glacier. “You just cannot guess what the water structure might look like in these zones until you observe it,” he says.

But more work is needed to fully understand Thwaites and how it will further change as the world continues to warm. The glacier consists of two side-by-side fast-moving lanes of ice — one moving 3 kilometers per year, the other about 1 kilometer per year. Due to safety concerns, the team visited the slower lane — which still proved extremely challenging. Rignot says that scientists must eventually visit the fast lane, whose upper surface is more cracked up with crevasses — making it even harder to land aircraft and operate field camps.

The research reported today “is a very important step, but it needs to be followed by a second step,” the investigation of the glacier’s fast lane, he says. “It doesn’t matter how hard it is.”

Forget screwdrivers or drills. A stick and a straw make for a great cockatoo tool kit.

Some Goffin’s cockatoos (Cacatua goffiniana) know whether they need to have more than one tool in claw to topple an out-of-reach cashew, researchers report February 10 in Current Biology. By recognizing that two items are necessary to access the snack, the birds join chimpanzees as the only nonhuman animals known to use tools as a set.

The study is a fascinating example of what cockatoos are capable of, says Anne Clark, a behavioral ecologist at Binghamton University in New York, who was not involved in the study. A mental awareness that people often attribute to our close primate relatives can also pop up elsewhere in the animal kingdom.
A variety of animals including crows and otters use tools but don’t deploy multiple objects together as a kit (SN: 9/14/16; SN: 3/21/17). Chimpanzees from the Republic of Congo’s Noubalé-Ndoki National Park, on the other hand, recognize the need for both a sharp stick to break into termite mounds and a fishing stick to scoop up an insect feast (SN: 10/19/04).

Researchers knew wild cockatoos could use three different sticks to break open fruit in their native range of Indonesia. But it was unclear whether the birds might recognize the sticks as a set or instead as a chain of single tools that became necessary as new problems arose, says evolutionary biologist Antonio Osuna Mascaró of the University of Veterinary Medicine Vienna.

Osuna Mascaró and colleagues first tested whether the cockatoos could learn to smack loose a cashew placed inside a clear box and behind a thin paper barrier, akin to a chimpanzee’s hunt for termites. Six out of 10 cockatoos reliably knocked the nut out of the box using a pointy stick to poke through the membrane and a plastic straw to fish for the cashew.

Two birds managed the task in less than 35 seconds on their first try. Both — a male named Figaro and a female named Fini — are experienced tool users, Osuna Mascaró says.

Figaro, Fini and three fellow cockatoos were more likely to use both stick and straw only when the box had a paper barrier inside. If the team removed the barrier, the birds selected the straw instead of the stick as their tool.

Even when the birds had to walk or fly to reach the box, the birds brought along both tools every time the box had a barrier. If there was no paper, the cockatoos usually brought only one, a sign the cockatoos recognized when they needed their entire tool kit to swipe a snack.
Three of the birds even learned to put the stick inside the straw to carry both at the same time. That made for more efficient transport, meaning the birds didn’t have to make two trips and waste energy. Two birds, Kiwi and Pippin, transported both tools together every time the box had a barrier. Kiwi rarely brought along both tools if there wasn’t paper, and Pippin did so half as often.

Trading off which tools to bring may have to do with strength. After Figaro learned to combine transport, he grabbed both tools in 16 out of 18 trials. That may be because he’s one of the stronger birds in the group, Osuna Mascaró says. For him, grabbing both tools at once isn’t a big deal. Kiwi and Pippin, on the other hand, are weaker than Figaro.

Cockatoos raised in the lab probably display more abilities than a wild bird might use on an average day, Clark says. “Nevertheless, this means they can do it,” she says. “That doesn’t mean that the wild adult male … can do the same thing as Figaro. But he would have probably been capable of doing that had he been raised like Figaro.”

A focus on family might be the key to personal well-being.

Surveys in the social sciences, such as those measuring happiness or health, tend to focus on the smallest unit: the individual. But two new studies, each surveying over 10,000 people worldwide, show that primary unit of analysis may need scaling up. One study suggests that people adhere to public health guidelines less to protect themselves than their loved ones. And the other study provides an explanation for why that may be the case: People the world over prioritize family happiness over their own.
Neither research team defined the term “family,” instead allowing respondents to interpret the term as they saw fit. As such, the results suggest that the exact nature of family, whether nuclear, blood-related or extended, does not matter.

The findings have important implications for society, says Karen Bogenschneider, a family policy expert at the University of Wisconsin–Madison who was not involved with either study. That’s because policy makers occasionally rely on research findings to develop programs such as those aimed at reducing substance abuse or inequality. When researchers frame societal issues in terms of the individual or community, so too do policy makers. And those programs may be less effective as a result.

For instance, several studies in the past couple decades have shown that including family members in addiction treatment programs lowers the addict’s risk of relapse and improves family relationships.

Moreover, these studies challenge the assumption that individualism has turned the self into the most important unit of survival (SN: 10/7/19).

Family bonds drove individuals to adopt pandemic-related health behaviors
The idea that policy makers can target family to change behavior comes as no surprise to Martha Newson, an anthropologist at Kent University in England. For years, Newson has studied a concept known as fusion, where an individual becomes so enmeshed in a larger social unit that she or he is willing to sacrifice personal well-being, or even survival, for the group (SN: 6/23/16).

At the onset of the pandemic, Newson and her team began studying how social fusion might be influencing behavior around the world during the pandemic.
From March to May 2020, over 13,000 participants from 122 countries were shown a sequence of five pictures, each with two circles, one for the self and the other for a given group such as family, country or all of humankind. In the first picture, the circles are far apart, but in subsequent pictures they grow closer and closer together until they fully overlap. Participants had to select one of the five pictures to indicate their level of fusion with the group. A participant had to select the fully overlapping circles to be considered fused to the group.

Participants also filled out scales to indicate how much they had performed a given public health action, such as social distancing or masking, in the previous week.

Participants who were fused to family were overrepresented among those reporting strong adherence to public health guidelines, Newson and colleagues reported January 13 in Science Advances. For instance, despite representing roughly a quarter of the participant pool, participants with strong family bonds constituted three-quarters of those who reported following social distancing guidelines. And almost half of participants with strong family bonds reported frequent handwashing compared with about one-third of participants with weaker family bonds.

Humans evolved in small-scale societies, Newson says. “When we have crises … these smaller units remain very important.”

On average, people value family happiness more than their own
Meanwhile, another group of researchers had begun to question the widely accepted belief that many happy individuals sum up to a happy society. That idea originated in the West, and has often been treated as universal, says Kuba Krys, a cross-cultural psychologist at the Polish Academy of Sciences in Warsaw.

But research over the years has indicated that non-Westerners may not value personal happiness as much as people in the West. For instance, outside the West, people tend to see happiness as more interdependent, or grounded in harmony and balance with others, than independent, or grounded in the self.

If happiness exists at least partially outside the individual, then Krys and his team wondered what unit researchers should study. They looked to family.

The team had roughly 13,000 participants from 49 countries indicate how much the perfect or ideal person would agree with statements in two commonly used surveys of well-being. Statements appeared both in the standard “I” framing and in a new family framing. For instance, participants reflected on how the ideal person would respond to both the statements, “In most ways, my life is close to ideal” and “In most ways, the life of my family is close to ideal.”

Nearly half of the participants valued family well-being over personal well-being, while less than a third preferred their own happiness, the team reports in an upcoming paper in the Journal of Cross-Cultural Psychology. Moreover, participants in even the most individualistic countries, including the United States, valued family, on average, more than self.
The word “family” has become associated with conservativism, Krys says. But family remains central to people’s lives, regardless of geography or political affiliation. “The shape of family has changed but family as an idea, as a basic unit, has not changed,” he says. “I would advise progressives … not to be afraid of touching on family topics.”

Bogenschneider’s research backs up this point. In a study of more than 200 state legislators, she and colleagues found that while abortion and same-sex marriage remain highly polarized, policy makers tend to view other family issues, such as those involving domestic violence, juvenile crime or teen pregnancy, as largely bipartisan.

This suggests that issues that aren’t typically centered around family, such as climate change or inequality, could be framed in terms of family to garner wider support, Bogenschneider says. Researchers who are seeking to translate their findings into policy and advocates who are advancing particular causes could, she adds, “elevate policy makers’ interest in those issues by focusing on families and family contributions.”

In shallow coastal waters of the Indian and Pacific oceans, a seagrass-scrounging cousin of the manatee is in trouble. Environmental strains like pollution and habitat loss pose a major threat to dugong (Dugong dugon) survival, so much so that in December, the International Union for Conservation of Nature upgraded the species’ extinction risk status to vulnerable. Some populations are now classified as endangered or critically endangered.

If that weren’t bad enough, the sea cows are at risk of losing the protection of a group who has long looked after them: the Torres Strait Islanders. These Indigenous people off the coast of Australia historically have been stewards of the dugong populations there, sustainably hunting the animals and monitoring their numbers. But the Torres Strait Islanders are also threatened, in part because sea levels are rising and encroaching on their communities, and warmer air and sea temperatures are making it difficult for people to live in the region.
This situation isn’t unique to dugongs. A global analysis of 385 culturally important plant and animal species found that 68 percent were both biologically vulnerable and at risk of losing their cultural protections, researchers report January 3 in the Proceedings of the National Academy of Sciences.

The findings clearly illustrate that biology shouldn’t be the primary factor in shaping conservation policy, says cultural anthropologist Victoria Reyes-García. When a culture dwindles, the species that are important to that culture are also under threat. To be effective, more conservation efforts need to consider the vulnerability of both the species and the people that have historically cared for them, she says.

“A lot of the people in the conservation arena think we need to separate people from nature,” says Reyes-García, of the Catalan Institution for Research and Advanced Studies and the Autonomous University of Barcelona. But that tactic overlooks the caring relationship many cultural groups – like the Torres Strait Islanders – have with nature, she says.

“Indigenous people, local communities, also other ethnic groups – they are good stewards of their biodiversity,” says Ina Vandebroek, an ethnobotanist at the University of the West Indies at Mona in Kingston, Jamaica, who was not involved in the work. “They have knowledge, deep knowledge, about their environments that we really cannot overlook.”

One way to help shift conservation efforts is to give species a “biocultural status,” which would provide a fuller picture of their vulnerability, Reyes-García and colleagues say. In the study, the team used existing language vitality research to determine a culture’s risk of disappearing: The more a cultural group’s language use declines, the more that culture is threatened. And the more a culture is threatened, the more culturally vulnerable its important species are. Researchers then combined a species’ cultural and biological vulnerability to arrive at its biocultural status. In the dugong’s case, its biocultural status is endangered, meaning it is more at risk than its IUCN categorization suggests.

This intersectional approach to conservation can help species by involving the people that have historically cared for them (SN: 3/2/22). It can also highlight when communities need support to continue their stewardship, Reyes-García says. She hopes this new framework will spark more conservation efforts that recognize local communities’ rights and encourage their participation – leaning into humans’ connection with nature instead of creating more separation (SN: 3/8/22).

Are your cats play fighting or fighting fur real?

It turns out that certain behaviors in domestic cats could be telltale signs that an interaction is friendly, aggressive or something in between, researchers report January 26 in Scientific Reports.

“It is a question we hear a lot from cat owners,” says cat behavior expert Mikel Delgado of Feline Minds, a cat behavior consulting company in Sacramento, Calif., who was not involved in the study. “So I was excited to see that researchers are taking on this topic.”
Scientists have studied cats’ social relationships — both with other cats and humans — but it can be tricky to tell whether two cats are playing or fighting, says veterinarian and cat behavior researcher Noema Gajdoš-Kmecová of the University of Veterinary Medicine and Pharmacy in Košice, Slovakia (SN: 9/23/19).

Sometimes cat owners miss the signs of a tense relationship because they think their pets are just playing, which can lead to stress and illness in the animals, she says. Other times, owners rehome their cats after incorrectly assuming their pets are fighting.

To assess and categorize interactions, Gajdoš-Kmecová and colleagues watched about 100 videos of different cats interacting in pairs. After viewing around one-third of the videos, Gajdoš-Kmecová identified six types of behaviors, including wrestling and staying still. She then watched all of the videos and noted how often each cat exhibited one of the specified behaviors, and for how long. By running statistical analyses on the behaviors, she pinpointed three types of interactions between the cat pairs: playful, aggressive and intermediate.

To confirm the outcome, other members of the team also watched the videos and classified each interaction between felines.

Some clear connections emerged. Quietly wrestling, for instance, suggested playtime, whereas chasing and vocalizations, like growling, hissing or gurgling, implied aggressive encounters.

Intermediate interactions had elements of both playful and aggressive encounters, but especially included prolonged activity of one cat toward the other, such as pouncing on or grooming its fellow feline. These in-between encounters could hint that one cat wants to keep playing while the other doesn’t, with the more playful cat gently nudging to see if its partner wants to continue, the authors say.
This work provides initial insights into cat interactions, Gajdoš-Kmecová says, but it’s just the start. In the future, she plans to study more subtle behaviors, like ear twitches and tail swishes. Both Gajdoš-Kmecová and Delgado also stress that one contentious encounter doesn’t necessarily signal a cat-astrophic relationship.

“This is not just about one interaction,” Gajdoš-Kmecová says. Owners “really should look into the different, multiple interactions in multiple periods of life of the cats and then put it into context.”

The night sky has been brightening faster than researchers realized, thanks to the use of artificial lights at night. A study of more than 50,000 observations of stars by citizen scientists reveals that the night sky grew about 10 percent brighter, on average, every year from 2011 to 2022.

In other words, a baby born in a region where roughly 250 stars were visible every night would see only 100 stars on their 18th birthday, researchers report in the Jan. 20 Science.
The perils of light pollution go far beyond not being able to see as many stars. Too much brightness at night can harm people’s health, send migrating birds flying into buildings, disrupt food webs by drawing pollinating insects toward lights instead of plants and may even interrupt fireflies trying to have sex (SN: 8/2/17; SN: 8/12/15).

“In a way, this is a call to action,” says astronomer Connie Walker of the National Optical-Infrared Astronomy Research Laboratory in Tucson. “People should consider that this does have an impact on our lives. It’s not just astronomy. It impacts our health. It impacts other animals who cannot speak for themselves.”

Walker works with the Globe at Night campaign, which began in the mid-2000s as an outreach project to connect students in Arizona and Chile and now has thousands of participants worldwide. Contributors compare the stars they can see with maps of what stars would be visible at different levels of light pollution, and enter the results on an app.

“I’d been quite skeptical of Globe at Night” as a tool for precision research, admits physicist Christopher Kyba of the GFZ German Research Centre for Geosciences in Potsdam. But the power is in the sheer numbers: Kyba and colleagues analyzed 51,351 individual data points collected from 2011 to 2022.

“The individual data are not precise, but there’s a whole lot of them,” he says. “This Globe at Night project is not just a game; it’s really useful data. And the more people participate, the more powerful it gets.”

Those data, combined with a global atlas of sky luminance published in 2016, allowed the team to conclude that the night sky’s brightness increased by an average 9.6 percent per year from 2011 to 2022 (SN: 6/10/16).

Most of that increase was missed by satellites that collect brightness data across the globe. Those measurements saw just a 2 percent increase in brightness per year over the last decade.
There are several reasons for that, Kyba says. Since the early 2010s, many outdoor lights have switched from high-pressure sodium lightbulbs to LEDs. LEDs are more energy efficient, which has environmental benefits and cost savings.

But LEDs also emit more short-wavelength blue light, which scatters off particles in the atmosphere more than sodium bulbs’ orange light, creating more sky glow. Existing satellites are not sensitive to blue wavelengths, so they underestimate the light pollution coming from LEDs. And satellites may miss light that shines toward the horizon, such as light emitted by a sign or from a window, rather than straight up or down.

Astronomer and light pollution researcher John Barentine was not surprised that satellites underestimated the problem. But “I was still surprised by how much of an underestimate it was,” he says. “This paper is confirming that we’ve been undercounting light pollution in the world.”

The good news is that no major technological breakthroughs are needed to help fix the problem. Scientists and policy makers just need to convince people to change how they use light at night — easier said than done.

“People sometimes say light pollution is the easiest pollution to solve, because you just have to turn a switch and it goes away,” Kyba says. “That’s true. But it’s ignoring the social problem — that this overall problem of light pollution is made by billions of individual decisions.”

Some simple solutions include dimming or turning off lights overnight, especially floodlighting or lights in empty parking lots.

Kyba shared a story about a church in Slovenia that switched from four 400-watt floodlights to a single 58-watt LED, shining behind a cutout of the church to focus the light on its facade. The result was a 96 percent reduction in energy use and much less wasted light , Kyba reported in the International Journal of Sustainable Lighting in 2018. The church was still lit up, but the grass, trees and sky around it remained dark.

“If it was possible to replicate that story over and over again throughout our society, it would suggest you could really drastically reduce the light in the sky, still have a lit environment and have better vision and consume a lot less energy,” he says. “This is kind of the dream.”

Barentine, who leads a private dark-sky consulting firm, thinks widespread awareness of the problem — and subsequent action — could be imminent. For comparison, he points to a highly publicized oil slick fire on the Cuyahoga River, outside of Cleveland, in 1969 that fueled the environmental movement of the 1960s and ’70s, and prompted the U.S. Congress to pass the Clean Water Act.

“I think we’re on the precipice, maybe, of having the river-on-fire moment for light pollution,” he says.

Shape-shifting liquid metal robots might not be limited to science fiction anymore.

Miniature machines can switch from solid to liquid and back again to squeeze into tight spaces and perform tasks like soldering a circuit board, researchers report January 25 in Matter.

This phase-shifting property, which can be controlled remotely with a magnetic field, is thanks to the metal gallium. Researchers embedded the metal with magnetic particles to direct the metal’s movements with magnets. This new material could help scientists develop soft, flexible robots that can shimmy through narrow passages and be guided externally.
Scientists have been developing magnetically controlled soft robots for years. Most existing materials for these bots are made of either stretchy but solid materials, which can’t pass through the narrowest of spaces, or magnetic liquids, which are fluid but unable to carry heavy objects (SN: 7/18/19).

In the new study, researchers blended both approaches after finding inspiration from nature (SN: 3/3/21). Sea cucumbers, for instance, “can very rapidly and reversibly change their stiffness,” says mechanical engineer Carmel Majidi of Carnegie Mellon University in Pittsburgh. “The challenge for us as engineers is to mimic that in the soft materials systems.”

So the team turned to gallium, a metal that melts at about 30° Celsius — slightly above room temperature. Rather than connecting a heater to a chunk of the metal to change its state, the researchers expose it to a rapidly changing magnetic field to liquefy it. The alternating magnetic field generates electricity within the gallium, causing it to heat up and melt. The material resolidifies when left to cool to room temperature.

Since magnetic particles are sprinkled throughout the gallium, a permanent magnet can drag it around. In solid form, a magnet can move the material at a speed of about 1.5 meters per second. The upgraded gallium can also carry about 10,000 times its weight.

External magnets can still manipulate the liquid form, making it stretch, split and merge. But controlling the fluid’s movement is more challenging, because the particles in the gallium can freely rotate and have unaligned magnetic poles as a result of melting. Because of their various orientations, the particles move in different directions in response to a magnet.

Majidi and colleagues tested their strategy in tiny machines that performed different tasks. In a demonstration straight out of the movie Terminator 2, a toy person escaped a jail cell by melting through the bars and resolidifying in its original form using a mold placed just outside the bars.
On the more practical side, one machine removed a small ball from a model human stomach by melting slightly to wrap itself around the foreign object before exiting the organ. But gallium on its own would turn to goo inside a real human body, since the metal is a liquid at body temperature, about 37° C. A few more metals, such as bismuth and tin, would be added to the gallium in biomedical applications to raise the material’s melting point, the authors say. In another demonstration, the material liquefied and rehardened to solder a circuit board.
Although this phase-shifting material is a big step in the field, questions remain about its biomedical applications, says biomedical engineer Amir Jafari of the University of North Texas in Denton, who was not involved in the work. One big challenge, he says, is precisely controlling magnetic forces inside the human body that are generated from an external device.

“It’s a compelling tool,” says robotics engineer Nicholas Bira of Harvard University, who was also not involved in the study. But, he adds, scientists who study soft robotics are constantly creating new materials.

“The true innovation to come lies in combining these different innovative materials.”

The Arctic today is a hostile place for most primates. But a series of fossils found since the 1970s suggest that wasn’t always the case.

Dozens of fossilized teeth and jaw bones unearthed in northern Canada belonged to two species of early primates — or at least close relatives of primates — that lived in the Arctic around 52 million years ago, researchers report January 25 in PLOS ONE. These remains are the first primate-like fossils ever discovered in the Arctic and tell of a groundhog-sized animal that may have skittered across trees in a swamp that once existed above the Arctic Circle.
The Arctic was significantly warmer during that time. But creatures still had to adapt to extreme conditions such as long winter months without sunlight. These challenges make the presence of primate-like creatures in the Arctic “incredibly surprising,” says coauthor Chris Beard, a paleontologist at the University of Kansas in Lawrence. “No other primate or primate relative has ever been found this far north so far.”

Between frigid temperatures, limited plant growth and months of perpetual darkness, living in the modern Arctic isn’t easy. This is especially true for primates, which evolved from small, tree-dwelling creatures that largely fed on fruit (SN: 6/5/13). To this day, most primates — humans and few other outliers like Japan’s snow monkeys excepted — tend to stick to tropical and subtropical forests, largely found around the equator.

But these forests haven’t always been confined to their present location. During the early Eocene Epoch, which started around 56 million years ago, the planet underwent a period of intense warming that allowed forests and their warm-loving residents to expand northward (SN: 11/3/15).

Scientists know about this early Arctic climate in part because of decades of paleontological work on Ellesmere Island in northern Canada. These digs revealed that the area was once dominated by swamps not unlike those found in the southeastern United States today. This ancient, warm, wet Arctic environment was home to a wide array of heat-loving animals, including giant tapirs and crocodile relatives.
For the new study, Beard and his colleagues examined dozens of teeth and jawbone fossils found in the area, concluding that they belong to two species, Ignacius mckennai and Ignacius dawsonae. These two species belonged to a now-extinct genus of small mammals that was widespread across North America during the Eocene. The Arctic variants probably made their way north as the planet warmed, taking advantage of the new habitat opening up near the poles.

Scientists have long debated whether this lineage can be considered true primates or whether they were simply close relatives. Regardless, it’s still “really weird and unexpected” to find primates or their relatives in the area, says Mary Silcox, a vertebrate paleontologist at the University of Toronto Scarborough.

For one thing, Ellesmere Island was already north of the Arctic Circle 52 million years ago. So while conditions may have been warmer and wetter, the swamp was plunged into continuous darkness during the winter months.

Newly arrived Ignacius would have had to adapt to these conditions. Unlike their southern kin, the Arctic Ignacius had unusually strong jaws and teeth suited to eating hard foods, the researchers found. This may have helped these early primates feed on nuts and seeds over the winter, when fruit wasn’t as readily available.

This research can shed light on how animals can adapt to live in extreme conditions. “Ellesmere Island is arguably the best deep time analog for a mild, ice-free Arctic,” says Jaelyn Eberle, a vertebrate paleontologist at the University of Colorado Boulder.

Studying how plants and animals adapted to this remarkable period in Arctic history, Beard says, could offer clues to the Arctic’s future residents.