Children with autism excel at motion detection test

On a test of visual perception, children with autism perceive moving dots with more clarity than children without the disorder. The results, published in the May 6 Journal of Neuroscience, reveal a way in which children with autism see the world differently.

When asked to determine the overall direction of a mess of dots moving in slightly different directions, children with autism outperformed children without the disorder. Other tests of motion detection didn’t turn up any differences. The results suggest that children with autism may be taking in and combining more motion information than children without autism, says study coauthor Catherine Manning of the University of Oxford. This heightened ability may contribute to feelings of sensory overload, the researchers suggest.

Stimulating nerve cells stretches time between thinking, doing

A zap to the head can stretch the time between intention and action, a new study finds. The results help illuminate how intentions arise in the brain.

The study, published in the May 6 Journal of Neuroscience, “provides fascinating new clues” about the process of internal decision making, says neuroscientist Gabriel Kreiman of Harvard University. These sorts of studies are bringing scientists closer to “probing some of the fundamental questions about who we are and why we do what we do,” he says.
Figuring out how the brain generates a sense of control may also have implications for people who lack those feelings. People with alien hand syndrome, psychogenic movement disorders and schizophrenia can experience a troubling disconnect between intention and action, says study coauthor Biyu Jade He of the National Institutes of Health in Bethesda, Md.

In the study, the researchers manipulated people’s intentions without changing their actions. The researchers told participants to click a mouse whenever the urge struck. Participants estimated when their intention to click first arose by monitoring a dot’s position on a clockface.

Intention to click usually preceded the action by 188 milliseconds on average, the team found. But a session of transcranial direct current stimulation, or tDCS, moved the realization of intention even earlier, stretching time out between awareness of intention and the action. tDCS electrodes delivered a mild electrical zap to participants’ heads, dialing up the activity of carefully targeted nerve cells. After stimulation, intentions arrived about 60 to 70 milliseconds sooner than usual. tDCS seemed to change certain kinds of brain activity that may have influenced the time shift, EEG recordings suggested.

The results highlight how thoughts and intentions can be separated from the action itself, a situation that appears to raise thorny questions about free will. But these tDCS zaps didn’t change the action outcome or participants’ feelings of control, only the reported timing of a person’s conscious intention.

Wandering planets, the smell of rain and more reader feedback

Free-range planets
Astronomers are puzzling over some space oddities: planets that don’t orbit stars. In “Wandering worlds” (SN: 4/4/15, p. 22), Ashley Yeager explored how these lonely rogues may alter the definition of a planet.

Tim Geho wanted to know more about how scientists locate homeless worlds. “Where does the light come from that allows rogue planets to be seen, either directly or via gravitational lensing?” he asked. “Is there some sort of fluorescence or luminescence involved or is [light] reflected from distant suns?”
Some rogues can be imaged directly because big planets can emit their own heat, Yeager says. Telescopes detect this heat as infrared light. Identifying a planet with gravitational lensing is also possible. In this case, astronomers use light from a distant star to infer the existence of a planet. First they track the movement of the star. From the viewpoint of Earth, when the star passes behind some unseen object, the hidden object’s gravity will bend the star’s light. How much the object bends the light reveals the object’s mass. If the mass is similar to the mass of a planet, then astronomers assume that the unseen object is a planet.

Readers also had their own suggestions for what to call these rogues. Jeff Barry jokingly proposed naming them “nibirus,” after the mythical doomsday planet that is supposed to crash into Earth. John Turner commented, “Some sources refer to these nomadic bodies as ‘planemos.’ I notice we’re avoiding using that word in this article, though it’s been used in Science News pieces in the past. What gives?”
Planemo never became widely used in the astronomy community, according to Penn State astronomer Kevin Luhman . He suggests sticking with brown dwarf, while others, like Michael Liu at the University of Hawaii in Honolulu, prefer the term free-floating planet.
New thoughts on old tools
Developing new categories for types of stone tools could help anthropologists craft a more accurate view of hominid evolution, Bruce Bower reported in “Reading the stones” (SN: 4/4/15, p. 16).

Discussions on Facebook and Twitter centered on how difficult it would be to re-create some of the tools. Some readers, like Grink, declared confidently, “I can make that.” Others thought the process would be challenging. “It’s a very difficult technique,” wrote Shashank Ac. “Most modern humans would not last a day in the Stone Age.”

Mark S. took the idea a step further, suggesting a Paleolithic reenactment week: “Have the specialists get together and try to hunt, butcher and live as putative Stone Age peoples would. It would probably shed all sorts of light on what tools were really important and under what conditions. Anyone caught ordering pizza would lose their publication rights.”

The scent of rain
Andrew Grant explained how falling water drops can kick soil chemicals into the air, creating that well-known poststorm earthy aroma, in “Why rain smells like that” (SN: 4/4/15, p. 5).

The story confirmed what reader Bo Grimes had long suspected: “Ever since I first noticed the phenomenon as a child, I assumed chemicals were released from the soil, though I probably thought of it in terms of splashed dirt.” Commenter Zk10 wrote, “For whatever reason, the earthy, natural smell of raindrops on hot sand has a wonderful calming effect on me. These smells are so faint you do not even realize they are there. You just feel better. Nice to know the science behind it.”

In “An oil spill’s aftermath” (4/18/15, p. 22), U.S. District Judge Carl Barbier’s ruling about the amount of oil released in the 2010 Deepwater Horizon spill in the Gulf of Mexico was expressed incorrectly. The judge ruled that 4 million barrels of oil exited the reservoir but that, after accounting for oil collected at the site, 3.19 million barrels was discharged into the Gulf.

Possible nearest living relatives to complex life found in seafloor mud

Cold mud from the seafloor has revealed signs of a new group of microbes that could be the nearest living relatives yet found to the domain of life that includes people and other creatures with fancy cell structures.

That mud carries DNA of a previously unknown and unusual phylum of one-celled microbes, researchers report online May 6 in Nature.

The microbes in this newly named Lokiarchaeota phylum carry the basic DNA of one-celled life called archaea, sisters to the domain of bacteria. Yet they possess roughly 100 genes that resemble those in eukaryotes, organisms with intricate structures in their cells.
“What was very surprising was the type of function of these genes,” says paper coauthor Thijs Ettema of Uppsala University in Sweden. What the genes do in Lokiarchaeota is still a matter of hypothesis. But in eukaryotes, many of these genes help with tasks not observed in archaea, such as changing cell shape and controlling internal compartments called vesicles.
The discovery of Lokiarchaeota could intensify debates about how living cells got complex. In recent decades, biologists largely embraced a broad view that divided living organisms into three vast domains: Two — archaea and bacteria — have single cells with no nuclei holding DNA or little structures tucked into membranes.

The third domain — eukaryotes — packages DNA inside cell nuclei and furnishes cells with internal nuggets such as mitochondria that specialize in handling energy. How such elaborate cells arose has puzzled biologists since they have not found clear-cut intermediate forms that suggest the evolutionary steps.

The new find has “genes that might provide a very good starting point to becoming eukaryote,” says James McInerney of the National University of Ireland Maynooth. It strengthens a hypothesis, called the ring of life, that eukaryotes arose not from a single ancient lineage but rather by mingling genes from two kinds of less-structured cells.

This hypothesis is especially promising in light of the discovery of Lokiarchaeota genes that might allow these organisms’ cell membranes to engulf other cells, says evolutionary biologist Mary O’Connell of Dublin City University. One objection to the ring-of-life idea has been the need to explain how genetic merging took place when neither archaea nor bacteria appear able to swallow other organisms. The new phylum, however, might have managed.

It took extreme feats of computing to discover the new genetic mix, Ettema says. Researchers extracted DNA from promising bits of mud in a sediment core coaxed from the ocean floor more than two kilometers deep along the Arctic Mid-Ocean Ridge. The researchers censused the DNA fragments with a computer program that sorted bits into separate kinds of life.

The Lokiarchaeota showed up as a blend of genes, some distinctive to archaea and others resembling those from eukaryotes. The more eukaryote-like genes aren’t likely to be genetic material snitched from full-fledged eukaryotes, Ettema says. Microbes do snitch, but these genes were scattered among bona fide archaea DNA instead of appearing in chunks, as stolen goods do. And though similar, they were not entirely like eukaryote genes.

Since these conclusions are based on computer analysis of DNA, “we have huge gaps in our knowledge of what these beasts actually are,” McInerney says. “There is a lot of work to do to try to really understand if their relatives 2 billion years ago were important for formation of the eukaryotic cell.”

Clouds in the Milky Way’s plasma bubbles came from the starry disk — and far beyond

Huge bubbles of plasma billowing out from the Milky Way’s center might contain scraps from all over the galaxy — and beyond.

A new look at gas clouds in the galaxy’s Fermi bubbles shows that the clouds contain stuff from the galaxy’s starry disk and from some mysterious other source. The finding could shed light on how galaxies in general live and die, astronomers report July 18 in Nature Astronomy.

The Fermi bubbles are giant blobs of plasma, tens of thousands of light-years tall, that extend on either side of the Milky Way’s galactic disk. When the bubbles were discovered in 2010, astronomers thought they could have been formed by newborn stars (SN: 11/9/10). These days, many astronomers are instead convinced the bubbles could have been blown by a massive, long-ago burp emitted from the galaxy’s supermassive black hole.
In the years that followed the discovery, astronomers also spotted clouds of relatively cool gas that seem to flit around within the bubbles, high above the starry disk. “We call them high velocity clouds, because we’re not very good at naming things,” says astrophysicist Trisha Ashley of the Space Telescope Science Institute in Baltimore.

Scientists thought the clouds had been ripped from the Milky Way’s bright starry disk and sent flying when the Fermi bubbles formed. That assumption has been used to calculate things like the age of the bubbles, which could offer a clue to their origins.

“It made sense, it was a logical assumption,” Ashley says. “But no one had ever tested the origin of these clouds.”

Now Ashley and colleagues have made a first effort to figure out where the clouds come from — and found a surprising answer.

Using new and archived data from several telescopes, she and her team measured the metal content — the abundances of all the elements heavier than helium — in 12 high velocity clouds entrenched in the Fermi bubbles. Then the researchers compared the clouds’ chemistries to those of stars in the Milky Way’s disk. If the clouds really did come from the disk, they should have metal contents like the sun and other disk stars, Ashley says. If not, their metal contents should be lower.

The team found a wide range of metals in the clouds, from less than a fifth of the sun’s to more than the sun’s. That means “these clouds have to originate in both the disk of the Milky Way and the halo of the Milky Way,” she says, referring to the chaotic cloud of gas and dust that surrounds the galaxy and provides it with fuel for new stars (SN: 7/12/18). “We haven’t figured out any other explanation.”

How those clouds got into the halo in the first place is still an open question, says Jessica Werk, an astronomer at the University of Washington in Seattle who was not involved in the study.

“There’s a number of ways these clouds can be produced, a number of origins and a number of fates,” she says. The clouds could have condensed within the halo on their own, or they could have been ripped from smaller galaxies cannibalized by the Milky Way, or a number of other origin stories (SN: 7/24/02). “This cycle in general is a very messy process.”

That messiness could help predict how the Milky Way’s star formation could change in the future. Cold gas clouds like these are the fuel for future star formation. If these clouds were born in the Milky Way’s gaseous halo but are being buoyed up by the Fermi bubbles instead of falling into the disk to form stars, that could eventually slow down the Milky Way’s star forming factories.

But if the gas clouds do end up forming new stars, that could mean the Milky Way is building new stars from a variety of cosmic sources.

“Ultimately what people are interested in is, how does the Milky Way sustain its star formation for a long time?” Werk says. “This tells you it’s not just one thing.”

Studying these bubbles and clouds can help astronomers understand other galaxies, too.

“We can see these things going on in other galaxies,” Ashley says. “But we have a front row seat to this one.”

Underground heat pollution could be tapped to mitigate climate change

The secret to efficiently heating some buildings might lurk beneath our feet, in the heat that humans have inadvertently stored underground.

Just as cities warm the surrounding air, giving rise to urban heat islands, so too does human infrastructure warm the underlying earth (SN: 3/27/09). Now, an analysis of groundwater well sites across Europe and parts of North America and Australia reveals that roughly a couple thousand of those locations possess excess underground heat that could be recycled to warm buildings for a year, researchers report July 8 in Nature Communications.
What’s more, even if humans managed to remove all this accumulated thermal pollution, existing infrastructure at about a quarter of the locations would continue to warm the ground enough that heat could be harvested for many years to come. That could reduce reliance on fossil fuels, and help mitigate climate change.

This work showcases the impact that underground heat recycling could have if harnessed on a large scale, says hydrogeologist Grant Ferguson of the University of Saskatchewan in Saskatoon, Canada, who was not involved in the study. “There’s a lot of untapped potential out there.”

Heat leaks into the subsurface from the warm roots of structures such as buildings, parking garages and tunnels, and from artificial surfaces such as asphalt, which absorb solar radiation. In Lyon, France, for example, researchers in 2016 found that human infrastructure warmed groundwater by more than 4 degrees Celsius.

Scientists don’t fully understand how heat pollution alters underground environments. But warming of the subsurface can cause contaminants, such as arsenic, to move through groundwater more readily.

Extracting the thermal pollution could be accomplished by piping groundwater to heat pumps at the surface. The water, warmed underground by all that trapped heat, could then warm buildings as it releases heat into their cooler interiors, says Susanne Benz, an environmental scientist at Dalhousie University in Halifax, Canada.

Harnessing underground heat in this way could provide some communities with a reliable and low-energy means to warm their homes, Benz says. “And if we don’t use it, it will just continue to accumulate,” she says.

Benz and her colleagues analyzed the population size, heating demand and groundwater temperature at more than 6,000 locations, most of which were in Europe. The researchers found that at about 43 percent of the locations — mostly those near highly populated areas — enough heat had accumulated in the top 20 meters of earth to satisfy a year’s worth of the local heating demand.

Curious about sustainability, the researchers also identified places where the continuous flow of heat into the underground — and not just the stockpiled thermal pollution — was high. Their calculations show that if all of the accumulated heat was first extracted, the heat that continued leaking from existing infrastructure could be harvested at about 25 percent of the 6,000 locations. At 18 percent of locations, this recycled heat could satisfy at least a quarter of the heating demand of the local population.

Constructing systems to take advantage of human heat pollution today could one day help residents harvest heat from climate change, the researchers say.

Using climate projections for the end of the century, the team probed the feasibility of extracting underground heat in a warmer world. In the most optimistic warming scenario considered, which assumes greenhouse gas emissions peak about the year 2040, the researchers found that climate change would warm the ground enough by the end of the century that underground heat recycling at 81 percent of the studied locations could meet more than a quarter of locals’ heating demands. If there are no efforts to curb emissions, that number rises to 99 percent of locations.

Though the researchers focused mostly on Europe, Benz says that other continents probably also possess abundant underground heat that could be harnessed. In Europe and elsewhere, heat recycling might be most feasible in suburban areas, she says, where there is sufficient accumulated underground heat to help meet local heating demands, and space to install heat recycling systems.

Looking ahead, Benz plans to investigate whether cooling the subsurface can help reduce aboveground temperatures in urban environments. “This might actually be a little additional tool to control [aboveground] urban heat.”

Here are experts’ answers to questions about COVID-19 vaccines for little kids

Four weeks ago, the U.S. Centers for Disease Control and Prevention signed off on COVID-19 vaccines for young children. Days later, doctors’ offices and clinics began rolling out shots for babies and toddlers.

In Portland, Ore., a clinic featuring bubbles, toys and a dance party delivered more than 1,100 shots in two days. In Arizona, more than 2,000 kids under 5 have received their first dose in about three weeks. Over the same time period in Fayetteville, Ga., one practice has given out roughly 100 doses to young kids.
As of July 14, nearly 400,000 kids under 5 have received at least one dose, the CDC reports. That’s about 2 percent of eligible children in this age group.

Pediatrician Eliza Hayes Bakken has seen an initial rush of parents who signed up for appointments as soon as the vaccines became available. “There’s a huge push of families that want to be in that first group that’s vaccinated,” says Bakken, who treats kids at Oregon Health & Sciences University Doernbecher Children’s Hospital in Portland. She suspects demand will soon taper off, following a pattern pediatricians have seen with vaccinations in older age groups.

Getting young kids vaccinated may be a long, slow haul, says Adrianne Hammershaimb, a pediatric infectious disease specialist at the University of Maryland School of Medicine in Baltimore. About half of U.S. parents with children under 4 said they were likely to get their kids the shot, her team reported last month in the Journal of the Pediatric and Infectious Diseases Society. That number is “lower than we’d like, but it’s not surprising,” she says.

Only about 55 percent of U.S. adults surveyed say COVID-19 vaccination has been extremely or very effective at limiting the coronavirus’ spread, the Pew Research Center in Washington, D.C., reported on July 7. In Hammershaimb’s experience, the issue isn’t that most parents are anti-vaxxers or mistrust all vaccines. Rather, “parents are genuinely concerned about the unknown,” she says. There’s a lot of misinformation out there, she notes, and people are trying to figure out what’s best for their kids.

As BA.5 continues to spark cases (now accounting for some 65 percent of new infections in the United States), parents are talking to doctors about COVID-19 risks, vaccine safety and vaccination timing. Here, Hammershaimb and three other pediatricians answer some common questions they’ve been getting.

Is COVID-19 really a problem for kids?
“This is one big question we get a lot,” Hammershaimb says. Kids are just as likely to catch COVID-19 as adults, though cases tend to be milder. Half of kids infected may have no symptoms at all.

The disease also tends to be deadlier for adults than children. In people ages 55 and older, COVID-19 is the third leading cause of death in the United States, scientists reported July 5 in JAMA Internal Medicine. But COVID-19 can hit kids hard, too. It ranks as the eighth leading cause of death in people 19 and under in the United States.
“You hear on TV that COVID is not a big deal for kids,” says Sara Goza, a pediatrician in Fayetteville, Ga., who served as president of the American Academy of Pediatrics in 2020. “That’s a little bit shocking.” In her practice, she’s seen infected children develop long COVID and chronic fatigue. “This disease is not without its complications,” she says.

Bakken’s 9-year-old son caught COVID-19 in 2020, before the vaccine came out. His case wasn’t particularly serious, but he did have long-term effects. He had to take more medication to control his asthma and be extra cautious playing sports. That may seem minor, Bakken says, but it didn’t feel that way for her son. “It affected his daily life.”

What are the side effects of COVID-19 vaccines?
Parents taking their young kids to get the shot can expect to see side effects similar to those common in other childhood vaccines. Fatigue, fussiness, redness at the injection site ​​— those are signs the body is responding to the vaccine like it’s supposed to, Bakken says. Some kids may have no side effects, and that’s OK, too, she says.

Vaccine safety is another topic parents have questioned (something that also came up in a recent Science News Twitter poll). Clinical trials and real-world data suggest the vaccines are safe for kids and adults, Bakken says. “Adverse events are exceedingly rare — much more rare than complications from COVID itself.”
Take myocarditis, the rare heart inflammation condition sometimes seen after getting Pfizer’s or Moderna’s mRNA COVID-19 vaccines. In boys between the ages of 12 and 17, myocarditis crops up in roughly 1 out of 10,000 following vaccination, scientists reported July 13 in the BMJ.

But teen boys are up to six times more likely to experience heart complications after COVID-19 infection compared with after vaccination, CDC scientists reported in April. In younger boys, ages 5 to 11, heart complications following vaccination are even more rare. And in most people with myocarditis following vaccination, symptoms improve quickly and the heart fully recovers.

Hammershaimb is keeping an eye on CDC and U.S. Food and Drug Administration monitoring systems that track potential adverse events to the vaccine. If anything concerning comes up, she says, ”we can intervene, halt the vaccination program, and take a close look at any cases that are reported.” Ultimately, she says, parents need to weigh the hypothetical risk of a rare adverse reaction against the known risks of COVID-19 infection.

Should parents wait until the fall to vaccinate their kids?
No, Hammershaimb says. She encourages parents to sign their kids up for their shots this summer, so they’ll head into fall with some coronavirus protection already built up. It’s possible that COVID-19 boosters targeting the omicron variant may be available as the school year kicks off, but that doesn’t mean parents should wait, she says. “We want kids to be as protected as they can be when they go back to the classroom.”

Sophie Katz, a pediatric infectious disease doctor in Nashville, agrees. Though the current vaccines’ ability to prevent omicron infection in kids seems to wane rapidly, the shots continue to be effective against hospitalization, she wrote in a JAMA editorial in May. And a study of kids in Israel who had received the Pfizer vaccine found that two doses offered moderate protection against the original omicron variant, scientists reported in the New England Journal of Medicine on June 29.

Katz’s 13-month-old baby has already had COVID-19, but she says, “I am 100 percent going to get her vaccinated.” For Katz, it’s a matter of protecting her child from severe disease. “I will do anything to keep my daughter out of the hospital.”