Time is out of joint on Venus. The planet’s thick air, which spins much faster than the solid globe, may push against the flanks of mountains and change Venus’ rotation rate.
Computer simulations show that the thick Venusian atmosphere, whipping around the planet at 100 meters per second, exerts enough push against a mountain on one side and suction on the other side to speed the planet’s rotation rate by about two minutes each Venus day, according to a study in Nature Geoscience June 18. That’s not much, considering that the planet rotates just once every 243 Earth days. By comparison, Venus’ atmosphere rotates about once every four Earth days. Precise measurements of the planet’s rotation rate have varied by about seven minutes, however. The push and pull of the air over the mountains could help explain the mismatch, with some other force — possibly the gravitational influence of the sun — slowing the planet’s spin back down. The simulations by UCLA planetary scientist Thomas Navarro and colleagues are the first to account for a 10,000-kilometer-long wave in Venus’ cloud tops , spotted in 2015 by the Japanese space agency’s Akatsuki spacecraft (SN: 2/18/17, p. 5) . Similar waves are launched into the atmosphere on Earth when air flows over a mountain, but they normally dissipate quickly as opposing winds break them up. Venus’ atmosphere rotates so much faster than the planet and in such a uniform direction that the waves could persist for a long time. “This work is very interesting,” says planetary scientist Tetsuya Fukuhara of Rikkyo University in Tokyo, one of the researchers who discovered the atmosphere wave. The work helps explain where the wave comes from and addresses how Venus’ surface features affect the atmosphere, “which is the most important issue in the Venus atmospheric science.”
More detailed measurements of Venus’ rotation, possibly taken with a future lander (SN: 3/3/18, p. 14), could eventually help reveal details of Venus’ interior, such as the size of its core.
“Venus is the closest thing to Earth that we know of,” Navarro says, and yet its hot, thick, toxic atmosphere makes it utterly alien. “We’d like to know what’s inside.”
MADISON, Wis. — Giving children with autism a healthier mix of gut bacteria as a way to improve behavioral symptoms continued to work even two years after treatment ended.
The finding may solidify the connection between tummy troubles and autism, and provide more evidence that the gut microbiome — the collection of bacteria and other microbes that live in the intestines — can influence behavior.
“It’s a long way from saying there’s a cure for autism,” says Michael Hylin, a neuroscientist at Southern Illinois University in Carbondale who was not involved in the work. “But I think it’s a promising approach. It’s one that’s worthwhile.”
Children with autism spectrum disorders often have gastrointestinal problems. In previous studies, environmental engineer Rosa Krajmalnik-Brown of Arizona State University in Tempe and colleagues discovered that children with autism had fewer types of bacteria living in their guts than typically developing children did. And many of the kids were missing Prevotella bacteria, which may help regulate immune system actions. The researchers wondered whether altering the children’s cocktail of gut microbes to get a more diverse and healthier mix might help fix both the digestive issues and the behavioral symptoms associated with autism. In a small study of 18 children and teenagers with autism, the scientists gave kids fecal transplants from healthy donors over eight weeks. During and two months after the treatment, the kids had fewer gastrointestinal problems, including diarrhea, constipation, abdominal pain and indigestion, than before the therapy. Autism symptoms, such as hyperactivity, repetitive actions and irritability, also improved and seemed to be getting even better at the end of the trial than immediately after treatment ended, the team reported last year in Microbiome. But no one knew whether the improvements would last.
Krajmalnik-Brown announced the results of a two-year, follow-up study July 10 at the Beneficial Microbes Conference. The children had kept many of the Prevotella and other beneficial bacteria gained during treatment. And the diversity of bacteria in the children’s guts was even greater two years later than it was two months after the therapy ended, Krajmalnik-Brown said.
Some of the children’s stomach troubles had worsened slightly. But on average, scores on a gastrointestinal-symptoms scale were still more than 60 percent better than before kids received the transplants. The real surprise was that the kids’ autism symptoms continued to lessen two years after the therapy ended. Still, the study was small. “Don’t try this at home,” Krajmalnik-Brown cautioned.
The children were ages 7 to 16 when the study started. Ideally, treatment would begin at younger ages, Krajmalnik-Brown said, but the researchers have not gotten approval to conduct the research in younger children.
Next, the scientists need to make sure that the improved behavioral symptoms are really due to fecal transplants. The team will put the idea to the test in a study of the therapy in adults with autism.
The definite detection of nonterrestrial neutrinos, whether from the sun or from beyond the solar system, will yield a far deeper understanding of stellar interiors and, therefore, of how today’s universe came to be. — Science News, July 20, 1968.
Update In May 1968, researchers reported that a particle detector in South Dakota spotted ghostly subatomic particles called neutrinos from the sun, but only about a third as many as theories predicted. The shortage vexed physicists for decades, until the 2001 discovery that many of the sun’s electron neutrinos — the only kind the South Dakota detector was designed to find — switch flavors on their way to Earth, becoming muon and tau neutrinos (SN: 6/23/01, p. 388). That switch accounted for the sun’s missing neutrinos. Detectors have also glimpsed neutrinos spawned by supernova 1987A (SN: 3/7/87, p. 148) and even a supermassive black hole (SN Online: 7/12/18).
Using tiny 2-D materials, researchers have built microscopic chemical sensors that can be sprayed in an aerosol mist. Spritzes of such minuscule electronic chips, described online July 23 in Nature Nanotechnology, could one day help monitor environmental pollution or diagnose diseases.
Each sensor comprises a polymer chip about 1 micrometer thick and 100 micrometers across (about as wide as a human hair) overlaid with a circuit made with atomically thin semiconducting materials (SN Online: 2/13/18). This superflat circuit includes a photodiode, which converts ambient light into electric current, and a chemical detector. This chemical detector is composed of a 2-D material that conducts electric current more easily if the material binds with a specific chemical in its environment. Researchers can choose from a vast menu of 2-D materials to fashion detectors that are sensitive to different chemicals, says study coauthor Volodymyr Koman, a chemical engineer at MIT (SN Online: 1/17/18). In lab experiments, Koman and colleagues created a sensor spray that detected toxic ammonia vapor inside a sealed section of piping, as well as a spray that ID’d soot particles sprinkled across a flat surface.
Right now, researchers can determine whether their sensors have come in contact with certain particles only after the fact — by collecting the chips and hooking them up to electrodes. These electrodes test how easily electric current flows through a chip’s chemical detector, which reveals whether it touched a particular chemical after it was sprayed. But future sensors could emit light signals when in contact with target particles, says study coauthor Michael Strano, a chemical engineer at MIT.
The team is also investigating ways to power the circuits without ambient light and to integrate multiple chemical detectors onto a single chip. The simpler, single-chemical detection systems tested so far are “only the beginning,” Koman says. “It’s very exciting,” says Kourosh Kalantar-Zadeh, an electrical and chemical engineer at the University of New South Wales in Sydney whose commentary on the study appears in the same issue of Nature Nanotechnology. Sprayable sensors could someday detect gas leaks, pollution from power plants, volatile organic compounds and other air and water contaminants (SN: 3/17/18, p. 12).
Being so tiny, the devices could also be injected into a person’s bloodstream to monitor its chemical composition for medical purposes — like a blood test that wouldn’t require drawing any blood, Kalantar-Zadeh says. Or chemical sensors could be taken as nasal spray or swallowed to track digestive health (SN Online: 1/8/18). Unlike silicon-based devices that might pose environmental or health hazards, the polymers and the minute amounts of 2-D materials used to make the new devices are expected to be more biofriendly, he says.
The American Academy of Pediatrics is cautioning parents and pediatricians to avoid exposing children to eight chemicals found in food and in plastic packaging. The chemicals may be especially harmful to kids due to their small size, says the report published July 23 in Pediatrics. Pregnant women should also avoid the chemicals. And lower-income families who eat a lot of prepackaged foods could be at greater risk for exposure.
The chemicals include nitrates and nitrites, often added to processed meats as a preservative, as well as bisphenol A, or BPA, which is used to make durable plastics and has been linked to cancer, obesity and cardiovascular disease (SN: 10/3/15, p. 12). Also listed are phthalates, which help make plastic flexible, and perfluoroalkyl chemicals, or PFCs, which are resistant to stains, grease and water. These and other compounds have also been associated with endocrine disruption, obesity and insulin resistance, when cells don’t respond properly to insulin leading to an overproduction of the hormone (SN Online: 2/9/12). Some of these chemicals may also have neurocognitive effects, such as increased hyperactivity in children, says study coauthor Sheela Sathyanarayana, a physician and epidemiologist at the University of Washington in Seattle.
Scientists are unable to test the effects of these chemicals directly in humans, so evidence shows only that there is correlation, not causation, between exposure and disease.
To avoid these chemicals, the report suggests that parents buy fresh or frozen produce and skip processed meats packaged in plastic or food in metal cans, which can be lined with BPA. People should also avoid putting plastic containers in the dishwasher or microwave, the team says, where heat can draw chemicals out of plastic.
The researchers say that they hope the report prompts more strict regulation of these additives. “All parents should be able to know what they are feeding their children,” Sathyanarayana says.
NASA has a mantra for preparing spacecraft to launch: “Test as you fly.” The idea is to test the entire spacecraft, fully assembled, in the same environment and configuration that it will see in orbit.
But the Parker Solar Probe, set to launch August 11, is no ordinary spacecraft (SN Online: 7/5/18). And it’s headed to no ordinary environment. Parker will sweep through the sun’s scorching hot atmosphere for humankind’s first close encounter with the star at the center of the solar system. “Solar Probe is a little bit special,” says space plasma physicist Stuart Bale of the University of California, Berkeley. Getting the whole kit and caboodle into a setting that simulated the sun’s energetic particles, intense light and searing heat “was deemed impossible.” Scientists had to get creative to test the technology that will touch the sun, using everything from huge mirrors to dust tunnels to reams of paper.
Taking the heat The first order of business was to find materials that can stand the heat. The sun’s outer atmosphere, or corona, sizzles at millions of degrees Celsius — but it is so diffuse that it doesn’t pose much threat to the spacecraft (SN Online: 8/20/17). Direct sunlight, however, can heat exposed components to around 1370° Celsius. Two of the spacecraft’s scientific instruments, plus parts of its solar panels and its revolutionary heat shield, will be exposed to that searing sunlight at all times.
“Normal things … would melt,” says solar physicist Kelly Korreck of the Smithsonian Astrophysical Observatory in Cambridge, Mass. Korreck works on the Solar Wind Electrons Alphas and Protons instrument, known by its acronym SWEAP, which will catch the charged particles of the solar wind with a sensor called a Faraday cup (SN Online: 8/18/17). “It actually sticks around the heat shield and will be able to touch the sun,” Korreck says. “That cup is special.” To build the cup and other instruments that will see the sun directly, engineers settled on three main materials — a niobium alloy called C103 that is used in rocket engines, an alloy of titanium, zirconium and molybdenum called TZM, and tungsten. Some cables carrying power to the SWEAP cup are also lined with sapphire, a good insulator at high temperatures. And the probe’s heat shield is made of two kinds of carbon-based materials.
Figuring out how each of these materials would behave in space was tricky. Engineers couldn’t just use an oven to test the metals, which in heat can react with oxygen to rust or corrode. Carbon also can react with oxygen to combust. So the team had to test pieces of the instruments in airless vacuum chambers.
“Getting things hot on Earth is easier than you would think it is,” says Elizabeth Congdon of Johns Hopkins Applied Physics Laboratory in Laurel, Md., the lead engineer for the heat shield. “Getting things hot on Earth in vacuum is difficult.”
One way the Parker team mimicked the sun’s heat was using actual sunlight. Engineers took material samples to the world’s largest solar furnace, the PROMES facility in Odeillo, France. A series of 63 mirrors built on a hillside redirect sunlight onto an enormous concave mirror on the side of an eight-story building. That mirror then focuses the sunlight into a beam no more than 80 centimeters wide that heats materials to 3000° C inside a small vacuum chamber in a laboratory on stilts.
The beam is so hot, “you can take a two-by-four and swing it through the beam, and it burns right off,” Bale says. “Just a flash of smoke and it’s gone.” Bale leads another of the probe’s experiments called FIELDS that also needed heat testing. FIELDS is comprised of five long antennas, four of which will be exposed to the sun, that will measure electric and magnetic fields in the corona.
The SWEAP team needed an even more realistic simulator, one that would deliver intense sunlight at the angles that Parker will experience. They found an unlikely solution in IMAX film projectors, which emit light in a similar range of wavelengths to the sun.
“It took a completely custom test facility to do it,” says astrophysicist Anthony Case of the Smithsonian Astrophysical Observatory, who also works on the SWEAP instrument. He and his colleagues turned four IMAX projectors around so the lamps focused light into a small vacuum chamber, rather than spreading it across a huge screen. That gave the team the right light intensity and angles to test their instrument. Biting the dust Solar heat isn’t the only threat to the Parker Solar Probe. The region around the sun is also expected to be full of dust, left over from the formation of the planets. Scientists don’t know exactly how much dust to expect, but it’s likely to be moving almost as fast as the spacecraft, about 170 kilometers per second.
That’s a big worry for Parker’s twin telescopes, together called the Wide-field Imager for Solar Probe, or WISPR. One of the telescopes will be facing the direction that Parker is traveling, so it will be heading directly into the dust storm. “It can’t be protected,” says astrophysicist Russell Howard of the U.S. Naval Research Laboratory in Washington, D.C.
Dust particles hitting the telescope’s lens leave it pocked with little craters. Only 0.6 percent of the lens should be pitted by the end of Parker’s seven-year mission, according to computer models of dust in the inner solar system. But even a few pits can skew the data, so the team wanted to minimize the damage by choosing the right glass.
Howard and colleagues tested three possible materials for the lens in a dust acceleration tunnel at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. The tunnel accelerated charged iron particles, ranging from half a micrometer to 3 micrometers wide, to speeds between half a kilometer per second to 8 kilometers per second — fast enough for the scientists to extrapolate up to the dust speeds Parker might experience.
Sapphire withstood the barrage best, but it was unclear how it would behave as a lens. The team also rejected diamond-coated BK7 glass, commonly used for space telescopes, after the coating separated from the glass and left an extra ring around the impact spot. Regular, uncoated BK7 was the winner.
What’s what The Parker Solar Probe will use four sets of scientific instruments plus innovative self-protective measures to explore the environment near the sun. Take a tour of the spacecraft’s tech.
Tap or click to explore the tech. Swinging the temperatures Most of the spacecraft won’t have to worry about the dust or the sun’s extreme heat. Aside from SWEAP and FIELDS, almost everything is tucked behind the all-important heat shield.
That 2.5-meter-wide heat shield is made of carbon foam sandwiched between two carbon sheets. The whole thing is just 11.5 centimeters thick, and is coated on the sun-facing side with white ceramic paint to reflect as much sunlight as possible. Even then, that side could get as hot as 1370° C. But behind it, the bulk of the spacecraft will chill at an average of just 30° C (about 85° Fahrenheit).
“We hide in the shadows,” says solar physicist Eric Christian of NASA’s Goddard Space Flight Center in Greenbelt, Md. He’s the deputy principal investigator of the Integrated Science Investigation of the Sun experiment, which will measure solar particles across a wide range of energies. His team was able to build with ordinary materials and skip the rigorous heat testing. “We’re the lucky ones.” But Parker won’t always be near the sun. The spacecraft’s orbit will bring it as far from the sun as Venus, where temperatures are around –270° C. At that distance, the spacecraft that will touch the sun needs onboard heaters to keep it at 20° C. So Parker needed to be tested for cold and extreme temperature changes, too. “We’re not just worried about hot cycles, we’re worried about hot then cold then hot then cold,” says Congdon.
In January 2018, the entire spacecraft was lowered into a thermal vacuum chamber at NASA Goddard for two months of testing. The chamber, a cylinder standing 12 meters tall and 8 meters wide, was cooled to –190° C. A radiator glowing at about 315° C represented the heat coming from the back of the heat shield — but most of that heat never reached the scientific instruments since a titanium truss holds the heat shield at a safe distance from the spacecraft’s main body. The team cycled through hot and cold several times to simulate what Parker will experience.
Another challenge was keeping the probe’s solar panels cool. “You think, obviously, you’re going to the sun, solar power makes the most sense,” Congdon says. “But solar panels don’t like to get hot.” So the panels are threaded with veins that carry water to cool them off. The water absorbs heat from the panels and carries it to radiators that release the heat into space.
The solar panels are also on a shoulder joint, so they can tuck behind the heat shield at Parker’s closest approaches to the sun. Only the last row of cells will see the sun then. “That single row of cells can produce the same amount of power as the full wing can when we’re by the Earth,” says solar physicist Nicola Fox of Johns Hopkins Applied Physics Laboratory, the probe’s project scientist.But Parker won’t always be near the sun. The spacecraft’s orbit will bring it as far from the sun as Venus, where temperatures are around –270° C. At that distance, the spacecraft that will touch the sun needs onboard heaters to keep it at 20° C. So Parker needed to be tested for cold and extreme temperature changes, too. “We’re not just worried about hot cycles, we’re worried about hot then cold then hot then cold,” says Congdon.
In January 2018, the entire spacecraft was lowered into a thermal vacuum chamber at NASA Goddard for two months of testing. The chamber, a cylinder standing 12 meters tall and 8 meters wide, was cooled to –190° C. A radiator glowing at about 315° C represented the heat coming from the back of the heat shield — but most of that heat never reached the scientific instruments since a titanium truss holds the heat shield at a safe distance from the spacecraft’s main body. The team cycled through hot and cold several times to simulate what Parker will experience.
Another challenge was keeping the probe’s solar panels cool. “You think, obviously, you’re going to the sun, solar power makes the most sense,” Congdon says. “But solar panels don’t like to get hot.” So the panels are threaded with veins that carry water to cool them off. The water absorbs heat from the panels and carries it to radiators that release the heat into space.
The solar panels are also on a shoulder joint, so they can tuck behind the heat shield at Parker’s closest approaches to the sun. Only the last row of cells will see the sun then. “That single row of cells can produce the same amount of power as the full wing can when we’re by the Earth,” says solar physicist Nicola Fox of Johns Hopkins Applied Physics Laboratory, the probe’s project scientist. Up and away Before Parker can peer into the sun’s secrets, though, it must survive the trip to space.
The violent shaking during a spacecraft’s launch make it a tense time for scientists, even if they’ve tested all of the parts in an acoustic vibration chamber. Watching SWEAP’s vibration test “made me swear,” Korreck says. “It’s very scary to watch this thing you’ve spent 10 years on flop around as it keeps shaking more and more.”
Her team faced an unusual challenge in making Parker ready to rattle. It could not glue screws in place to prevent them from shaking loose, because epoxies would melt in the sunlight. So the SWEAP team twisted thin niobium wire by hand to tie hundreds of screws together in such a way that, if one comes loose, the others hold it in.
Launch can be a high-pressure time for the spacecraft, too — literally. Engineers initially thought Parker’s launch aboard a powerful Delta IV Heavy rocket, would subject the heat shield to a force 20 times that of Earth’s gravity, although later the team realized the launch force wouldn’t be so severe. To make sure the 72.5-kilogram shield wouldn’t bend or break, the team stacked 1,360 kilograms of paper on top of it.
Once it’s passed the final test of launching and deploying, Parker’s first scientific data should start trickling back to Earth in December. These missives will let scientists take the first step to unlocking the secrets of the sun’s superheated atmosphere and its energetic winds.
“It’s like being a proud parent. I worry that something could happen, but I don’t worry that we didn’t prepare or test her well,” Fox says. “I just hope she writes home every day with beautiful data.”
Editor’s note: This story was updated on August 27, 2018 to correct the cooling temperature in the thermal vacuum testing chamber at NASA Goddard.
Not content with protons and atomic nuclei, physicists took a new kind of particle for a spin around the world’s most powerful particle accelerator.
On July 25, the Large Hadron Collider, located at the laboratory CERN in Geneva, accelerated ionized lead atoms, each containing a single electron buddied up with a lead nucleus. Each lead atom normally has 82 electrons, but researchers stripped away all but one in the experiment, giving the particles an electric charge. Previously, the LHC had accelerated only protons and the nuclei of atoms, without any electron hangers-on.
Scientists hope the successful test means that the LHC could one day be used as a gamma-ray factory. Gamma rays, a type of high-energy light, could be produced by zapping beams of ionized atoms with laser light. That light would jostle the atoms’ electrons into higher energy states, and the accelerated atoms would emit gamma rays when the electrons later returned to lower energy states. Existing facilities make gamma rays from beams of electrons, but the LHC might be able to produce gamma rays at greater intensities.
More powerful beams of gamma rays would be useful for various scientific purposes, including searching for certain types of dark matter — mysterious particles that scientists believe exist in the universe but have yet to detect (SN: 11/12/16, p. 14). The gamma rays could also be used to produce beams of other particles, such as heavy, electron-like particles called muons, for use in new kinds of experiments.
Babies exposed to a Zika infection while in the womb are not out of the woods even if they look healthy at birth.
Nearly 1 in 10 of 1,450 babies examined developed neurological or developmental problems, such as seizures, hearing loss, impaired vision or difficulty crawling, a study from the U.S. Centers for Disease Control and Prevention finds. It’s the first tally of the health of children at least 1 year old who were born in Puerto Rico and other U.S. territories and exposed to Zika in utero. Overall, 14 percent of children exposed to Zika in the womb — about 1 in 7 — were harmed in some way by the virus, the researchers report online August 7 in Morbidity and Mortality Weekly Report. These babies were either born with a birth defect such as microcephaly — a condition in which a baby’s head is significantly smaller than it should be — or developed neurological symptoms that may be related to Zika, or both.
“Congenital Zika virus infection is quite serious, even beyond just the microcephaly,” says Peter Hotez, a pediatrician and microbiologist at Baylor College of Medicine in Houston, who was not involved in the report. “We’re still getting our arms around the full neurologic spectrum of illness” that is related to Zika.
The report also found that 6 percent of babies in the study had at least one birth defect caused by the virus, such as defects of the eye or brain or microcephaly (SN: 10/29/16, p. 14).
That’s fairly consistent with what’s seen in other countries hit by the Zika virus, Margaret Honein, director of CDC’s Division of Congenital and Developmental Disorders, said at a news conference. While a 2016 study suggested higher rates of birth defects in Brazil, “we think there isn’t a geographic difference” but more of a difference in how Zika-related birth defects are defined, she said. The data come from the U.S. Zika Pregnancy and Infant Registry, set up to monitor pregnant women with Zika virus infection and the health of their babies. The study focuses on those pregnancies reported from Puerto Rico, the U.S. Virgin Islands, American Samoa, the Federated States of Micronesia and the Marshall Islands. The children, all at least a year old, had received some follow-up medical care, such as brain imaging, hearing tests, eye exams or developmental screening. A report on pregnancies from the mainland United States is expected later this year.
Zika ravaged Brazil, Colombia and other countries of the Americas in 2015 and 2016. By 2017, the spread of the virus had slowed to a crawl (SN: 11/11/17, p. 12). But experts expect to see future outbreaks (SN: 12/23/17, p. 30).
“What makes this report unique is that we’re looking at the health of these babies beyond what was observed at birth,” Honein said. “This is really providing us with the first clues about how common some of these neurodevelopmental disabilities might be.”
Researchers suspect that health issues will continue to emerge for children exposed to Zika in the womb as they grow older. “This is why it is so absolutely critical that these babies receive care to identify issues as soon as possible,” Honein said, and that children continue to be monitored over time.
Conventional wisdom states that viruses work as lone soldiers. Scientists now report that some viruses also clump together in vesicles, or membrane-bound sacs, before an invasion. Compared with solo viruses, these viral “Trojan horses” caused more severe infections in mice, researchers report August 8 in Cell Host & Microbe.
Cell biologist Nihal Altan-Bonnet had been involved in discovering in 2015 that polioviruses can cluster together to invade cells in a petri dish. In the new study, Altan-Bonnet and a different group of colleagues find that transmission via virus clumps also occurs naturally with both rotavirus and norovirus, which can cause gastrointestinal illness. The scientists first identified norovirus cluster vesicles in patients’ stool samples, which was “eye-opening,” says Altan-Bonnet, who works at the National Institutes of Health in Bethesda, Md. “We can see these vesicles everywhere.”
Altan-Bonnet and her team infected live mice with either vesicle-packaged rotavirus or equal amounts of single virus particles. Vesicles were not only more successful in causing infections, they also caused infections that were more severe, the researchers found. In the mice, it took five times the amount of single virus particles to cause the same severity of infection as caused by the clustered viruses. It also took the mice two to four days longer to fight off the cluster-caused infections. While the mice were sick, the researchers found viral clumps in their feces, showing that the vesicles were able to survive the harsh environment of the GI system unscathed. It’s still unclear, however, if the viruses remain inside the vesicles to invade cells, and if so, how. The clusters act like a Trojan horse, Altan-Bonnet suggests. “The wooden horse would be the vesicle, and inside it you have all the soldiers.” She has several hypotheses for why viruses behave this way. Vesicles may help the viruses evade the immune system or replicate faster inside cells. “We really have to rethink the way we think about viruses,” she says.
Norovirus and rotavirus, which can be dangerous for children and the elderly, kill a combined total of about 265,000 children each year worldwide, mostly in developing countries (SN: 8/8/15, p. 5). The researchers hope the discovery of vesicle transmission will lead to better prevention methods and treatments, for example, by targeting the membranes containing the virus clusters.
Because the long-standing “dogma in the field” suggested viruses were transmitted individually, it’s not surprising that these vesicles were missed in earlier virus research, says Craig Wilen, a physician at the Yale School of Medicine who recently discovered what cells norovirus targets in mice (SN: 5/12/18, p. 14). “It’s probably been seen and just dismissed.”
Wilen says that there are still questions about viral clusters that need to be answered. For example, he says, “how does the virus escape the vesicle?” Other questions that remain include how the vesicle latches on to a cell’s surface, and what advantage the viruses actually get from packaging themselves together.
Peer pressure can be tough for kids to resist, even if it comes from robots.
School-aged children tend to echo the incorrect but unanimous responses of a group of robots to a simple visual task, a new study finds. In contrast, adults who often go along with the errant judgments of human peers resist such social pressure applied by robots, researchers report August 15 in Science Robotics.
“Rather than seeing a robot as a machine, children may see it as a social character,” says psychologist Anna-Lisa Vollmer of Bielefeld University, Germany. “This might explain why they succumb to peer pressure [applied] by robots.” Little is known about how either adults or children respond to the behavior of lifelike robots designed to interact with people, for example, as museum tour guides, child-care assistants and teaching aids.
In a preliminary examination of the influence of social robots, Vollmer’s group adapted a 1950s social psychology experiment in which most adults agreed with groups of peers who had been coached to say that lines of different lengths were in fact the same length (SN Online: 5/15/18).
Vollmer’s team observed comparable social conformity in a study of 60 British adults, ages 18 to 69, who judged line lengths after hearing the opinions of three peers who were working with the researchers. Participants usually endorsed peers’ unanimous, inaccurate judgments. Conformity vanished, however, when volunteers performed the task while sitting with three robots that, on some trials, agreed on an incorrect answer. Each robot was programmed to make periodic movements, such as blinking its eyes and briefly gazing at others. Robots spoke with distinctive, individualized voice pitches when making line judgments. When children sat with the robots, though, the kids frequently went all-in. The study’s 43 participating British grade-schoolers, aged 7 to 9, agreed with three-quarters of the robots’ unanimous, inaccurate answers. The kids did not participate in conformity experiments with trios of same-age human peers, given the difficulty of getting youngsters to act convincingly according to researchers’ directions.
Still, larger samples of volunteers are needed to confirm that kids usually cave to social pressure from robots. Cultural factors, such as being raised in a society that emphasizes individualism or group values, also may influence how people of all ages perceive and react to social robots.
Three unresolved issues in particular stand out, says psychologist and child development researcher Paul Harris of Harvard University. First, it’s unclear whether some robot behaviors, but not others, triggered conformity in children. A bot’s periodic head turns toward a child, for example, might sway that youngster’s choice more than the same robot’s eye blinks or finger movements. It’s also unclear why adults who bent to human peer pressure reversed course with robots.
Finally, Harris asks, “Would fine-tuning of the robots’ repertoire [of movements and vocalizations] eventually elicit deference even from adults?”
