Around 5,300 years ago, the Iceman dined on wild meat and grains before meeting his end in the Italian Alps. His last meal was high in fat and optimal for a high-altitude trek, researchers report July 12 in Current Biology.
Since his mummified remains were discovered in 1991, Ötzi’s life has undergone more scrutiny than many reality TV stars. His cause of death, his fashion, his tattoos, his ax, his cholesterol and his genetic instruction book, or genome, have all made headlines (SN 3/24/12, p.5). And in 2002, DNA analysis of samples from the Iceman’s lower intestine suggested that Ötzi ate red deer, goat and grains before he died. In 2011, radiological scans revealed that the mummy’s stomach contents were still intact (SN 9/24/11, p. 8). Now researchers are back with a more in-depth look inside the mummy’s gastrointestinal tract. Based on ancient DNA, proteins and other molecular data, the new analysis confirms the Iceman’s final menu: mountain goat ( Capra ibex), red deer ( Cervus elaphus ), einkorn wheat ( Triticum monococcum ) and other domesticated grains. Traces of a toxic fern ( Pteridium aquilinum ) also turned up — possibly a home remedy for an upset stomach, but more likely either as part of the meal or as a wrapping for the food. While the meal included protein, carbohydrates and fatty acids, fat makes up roughly 46 percent of the stomach contents. And most of that fat came from the goat meat. Test kitchen experiments suggest that the meat was either consumed fresh or slow-dried with smoke.
This high-fat diet probably wasn’t great for Ötzi’s genetic predisposition for heart disease, but it was ideal for the harsh mountain environment. “Even though it might not be tasty, up there you have to provide your body with energy, and fat is a really good energy source,” says study coauthor Frank Maixner of Eurac Research’s Institute for Mummy Studies in Bolzano, Italy. The meal could also be a sign of the times, Maixner says: Ötzi’s people were settled farmers, but when faced with colder temperatures, they may have had to fall back on hunter-gatherer ways. It’s just one meal, cautions Katie Manning of King’s College London who was not affiliated with the study. But “if you look at the palaeodietary evidence from Neolithic Europe, it is clear that wild resources continued to play an important role alongside domesticates, so hunting would have been a persistent activity, probably by specialized hunters.”
Now that researchers have a complete snapshot of the Iceman’s last meal, a census of Ötzi’s gut microbiome — the assortment of tiny organisms that made their home in the mummy’s stomach and intestines — could be next. Helicobacter pylori, a common stomach bug, has already been detected in the Iceman’s gut, and with it came hints of other inhabitants (SN: 2/6/16, p. 14). But Maixner wants to dig beyond “this tip of the iceberg.”
Robert Edwards and Richard Gardner of Cambridge University … say they have been able to remove rabbit embryos … then reimplant only the blastocysts destined to develop into the chosen sex. The implications are obvious and enormous. If this procedure could be extended easily to man there might, for instance, be imbalances, even fads, in the selection by parents of one sex of child over another. — Science News, August 3, 1968.
Update Edwards helped pioneer in vitro fertilization, resulting in the first IVF baby in 1978 and a Nobel Prize in physiology or medicine in 2010. He also foresaw technology’s potential for sex selection. With no sex selection, about 105 males are born for every 100 females worldwide. But in places where sex selection has been encouraged, through IVF and other methods, changes have resulted. In 1995, China’s ratio was 115 boys per 100 girls, according to U.N. estimates. By 2015, men outnumbered women in China by more than 42 million. In 2017, China ended its one-child policy.
Curl the fingers of your left hand over your palm and stick out your thumb like a hitchhiker. Now, you have a rough map of Antarctica — with the inside of your thumb playing the part of the Larsen C ice shelf, says glaciologist Ted Scambos of the National Snow and Ice Data Center in Boulder, Colo.
About a year ago, a massive iceberg roughly the size of Delaware broke off from that ice shelf, and it hasn’t moved much since (SN: 8/5/17, p. 6). The chunk of ice traveled just about 45 kilometers northeast before getting stuck behind an elevated ice promontory called the Bawden ice rise. Researchers monitoring satellite images of the iceberg say it’s been battering Bawden as winds and ocean currents push against the calved ice. That could be a problem, says Anna Hogg, an earth observation researcher at the University of Leeds in England. The Bawden ice rise acts “almost like scaffolding,” providing structure and stability to Larsen C, Hogg says. If it were destabilized, that could potentially lead to the collapse of the rest of the shelf, which could have implications for sea level rise.
That hasn’t happened yet. The iceberg may still be able to escape if it can twist around the tip of Bawden. “Currents and winds carry most of the icebergs in the same direction” — toward South Georgia Island, where many Antarctic icebergs eventually thin out and melt away, Scambos says.
Scientists are eager to study the seabed that was exposed when the iceberg first broke away. That environment could contain microbes and other tiny critters that have been inaccessible until now (SN Online: 10/13/17). An expedition by biologists to the area ended prematurely in February when thick ice prevented the ship from reaching the area (SN Online: 3/3/18). Another effort, aboard a South African icebreaker vessel, is planned for January 2019, Scambos says.
When a 78-year-old woman went to a hospital in Guangzhou, China, in November 2012 complaining of a headache, drowsiness and a stiff neck, doctors initially were puzzled. The patient had meningitis, but no signs of bacteria or viruses that can cause the illness. Then a cerebrospinal fluid test revealed she had a high number of white blood cells called eosinophils, a clue that she was fighting a parasitic infection. That helped the doctors zero in on a culprit: a thin, swirly-patterned worm called Angiostrongylus cantonensis. The woman was suffering from rat lungworm disease. So was her adult son.
But how were the pair infected? Rat lungworm disease, which gets its name from the fact that the worm eggs hatch in the lungs of rats, is commonly associated with ingesting snails or slugs (SN Online: 7/21/16). Infected rats poop out the worm larvae, which the mollusks can then pick up and pass on to humans if eaten. Yet the patients had eaten no slugs or snails. An investigation of the pair’s diet revealed they had eaten Chinese red-headed centipedes bought at the market. “Centipede is a common traditional Chinese medicine,” usually consumed in a dried powder, says Lingli Lu, a neurologist at Zhujiang Hospital in Guangzhou. The two patients, however, had eaten them raw.
Lu and her colleagues confirmed the source of the infection by testing 20 centipedes they bought from the same market. The team discovered A. cantonensis larvae that could infect humans in seven of the centipedes. The infected worms had an average of 56 larvae each. The case is the first evidence that eating raw centipedes contaminated with worm larvae can transmit rat lungworm disease, the researchers report July 30 in the American Journal of Tropical Medicine and Hygiene. The discovery adds to a growing list of hosts that can pass this parasite to humans. While the worm needs snails to complete its life cycle, other animals, called paratenic hosts, can eat the snails and then infect humans. Humans have gotten rat lungworm disease by eating freshwater shrimp, frogs, crabs and monitor lizards. Once inside the human body, the worms migrate to the brain, where they eventually die. While symptoms can be mild, infection can cause damage to the central nervous system, including brain inflammation, paralysis and even death. Infected humans cannot pass the disease to other people.
Rat lungworm is still considered rare (there have been about 3,000 recorded cases around the world), and the disease is most prevalent in tropical and subtropical regions, says Heather Stockdale Walden, a parasitologist at the University of Florida College of Veterinary Medicine in Gainesville. In the United States, the parasites are endemic in the Hawaiian Islands, and cases of rat lungworm have been reported as far north as Oklahoma.
Most cases in the United States occur from eating snails and slugs, which hide in unwashed produce. People should be aware of this parasite, Walden says, but not alarmed. “As long as you’re cooking your food [and] washing your produce, the likelihood of infection with the parasite is pretty low.”
Heading soccer balls may have high stakes for women’s brains, a study of amateur soccer players suggests.
Among amateur players who headed a similar number of balls, women had more signs of microscopic damage in their brains’ white matter than men, scientists report July 31 in Radiology.
Female athletes are known to have worse symptoms after brain injuries than male athletes, but a clear head-to-head comparison of post-heading brains hadn’t been done until now. From 2013 to 2016, study coauthor Michael Lipton of Albert Einstein College of Medicine in Bronx, N.Y., and colleagues recruited 98 soccer players from amateur teams, including from colleges. The researchers then compared male and female players who headed the ball a similar number of times over the past year. For men, that median estimate was 487 headers. Women had an estimated median of 469 headers.
Despite those similar numbers of head knocks, women’s brains had more spots that showed signs of microscopic damage. A type of magnetic resonance imaging scan called diffusion tensor imaging identified brain regions with changes in white matter, bundles of message-sending fibers. In some cases, those altered spots indicated possible damage to nerve cell axons and myelin, a protective coating that speeds neural signals along. In men, only three brain regions showed potential damage associated with heading frequency. In women, eight regions showed signs of damage with frequent heading. These brain changes weren’t enough to cause symptoms in the amateur soccer players. But repeated blows to the brain can contribute to memory loss and chronic traumatic encephalopathy, a disorder found in professional football players, soldiers and others whose brains suffer repetitive trauma (SN: 7/13/13, p. 18).
Researchers don’t know why women’s brains appear more at risk. Anatomical differences in heads and necks may play a role, along with genetics and hormones, the team writes.
Baseball is the best sport in the world for numberphiles. There are so many stats collected that the analysis of them even has its own name: sabermetrics. Like in Moneyball, team managers, coaches and players use these statistics in game strategy, but the mountain of available data can also be put to other uses.
Researchers have now mined baseball’s number hoard to show that climate change caused more than 500 home runs since 2010, with higher air temperatures contributing to the sport’s ongoing home run heyday. The results appear April 7 in the Bulletin of the American Meteorological Society. Many factors have led to players hitting it out of the park more often in the last 40 years, from steroid use to the height of the stitches on the ball. Blog posts and news stories have also speculated about whether climate change could be increasing the number of home runs, says Christopher Callahan of Dartmouth College (SN: 3/10/22). “But nobody had quantitatively investigated it.”
A climate change researcher and baseball fan, Callahan decided to dig into the sport’s mound of data in his free time to answer the question. After he gave a brief presentation at Dartmouth on the topic, two researchers from different fields joined the project.
That collaboration produced an analysis that is methodologically sound and “does what it says,” says Madeleine Orr, a researcher of the impacts of climate change on sports at Loughborough University London, who was not involved with the study.
The theorized relationship between global warming and home runs stems from fundamental physics — the ideal gas law says as temperature goes up, air density goes down, reducing air resistance. To see if home runs were happening due to warming, Callahan and colleagues took several approaches.
First, the team looked for an effect at the game level. Across more than 100,000 MLB games, the researchers found that a 1-degree Celsius increase in the daily high temperature increased the number of home runs in a game by nearly 2 percent. For example, a game like the one on June 10, 2019, where the Arizona Diamondbacks and Philadelphia Phillies set the record for most home runs in a game, would be expected to have 14 home runs instead of 13 if it were 4 degrees C warmer.
The researchers then ran game-day temperatures through a climate model that controls for greenhouse gas emissions and found that human-caused warming led to an average of 58 more home runs each season from 2010 to 2019. The analysis also showed that the overall trend of more home runs in higher temperatures goes back to the 1960s.
The team followed that analysis with a look at more than 220,000 individual batted balls, made possible by the Statcast system — where high-speed cameras have tracked the trajectory and speed of every ball hit during a game since 2015. The researchers compared balls hit in almost exactly the same way on days with different temperatures, while controlling for other factors like wind speed and humidity. That analysis showed a similar increase in home runs per degree Celsius as the game-level analysis, with only lower air density due to higher temperatures left to explain higher numbers of home runs. While climate change has “not been the dominant effect” causing more home runs, “if we continue to emit greenhouse gases strongly, we could see much more rapid increases in home runs” moving forward, Callahan says.
Some fans feel that the prevalence of home runs has made baseball duller, and it’s at least part of the reason that the MLB unveiled several new rule changes for the 2023 season, Callahan says.
Teams can adapt to rising temperatures by shifting day games to night games and adding domes to stadiums — the researchers found no effect of temperature on home runs for games played under a dome. But according to Orr, climate change may soon cause even more dramatic changes to America’s pastime, even with those adaptations.
Because the sport is susceptible to snow, storms, wildfires, flooding and heat at various points during the season, Orr says, “I don’t think, without substantial change, baseball exists in the current model” within 30 years.
Callahan agrees. “This sport, and all sports, are going to see major changes in ways that we cannot anticipate.”
In pictures from high above, the island of Gardi Sugdub resembles a container shipyard — small, brightly colored dwellings are jammed together cheek to jowl. At ground level, the island, one of more than 350 in the San Blas archipelago off the northern coast of Panama, is hot, flat and crowded. More than 1,000 people occupy the narrow dwellings that cover virtually every bit of the 150-by-400-meter island, which is slowly being swallowed by rising seas driven by climate change.
This year, about 300 families from Gardi Sugdub are expected to begin moving to a new community on the mainland. The resettlement plan was initiated by the residents there more than a decade ago when they could no longer deny that the island couldn’t accommodate the growing population. Rising seas and intense storms are only making the predicament more dire. Many of the older adults will opt to stay put. Some still don’t believe climate change poses a threat, but 70-year-old Pedro Lopez is not among them. Lopez, whose cousin interpreted for him during our Zoom interview, currently shares a small house with 16 family members and the family dog. He doesn’t plan to move. He knows Gardi Sugdub, translated as Crab Island, along with many others in the archipelago, is going underwater, but he believes it won’t happen within his lifetime.
The Indigenous Guna people have occupied these Caribbean islands since around the mid-1800s, when they abandoned the coastal jungle area near what is now the Panama-Colombia border to establish better trade and escape disease-carrying pests. Now, they are among the estimated hundreds of millions of people worldwide who by the end of the century may be forced to flee their land because of rising sea levels (SN: 5/9/20 & 5/23/20, p. 22).
In the Caribbean, sea level rise currently averages around 3 to 4 millimeters per year. As global temperatures continue to rise, it is expected to hit 1 centimeter per year or more by century’s end.
All of the islands of the San Blas archipelago will eventually be underwater and uninhabitable, says Steven Paton, who directs the Physical Monitoring Program at the Smithsonian Tropical Research Institute in Panama. “Some may need to be abandoned very soon while others not for many decades,” he adds. Anthropologist Anthony Oliver-Smith of the University of Florida in Gainesville has studied people who are forced from their homes by disasters for more than 50 years. Around the world, he says, climate change has become a major driver of displacement, with people who have limited resources facing the worst of it.
The impacts of climate change — flooding, rising seas and erosion — are threatening the Tuvaluans in the South Pacific, the Mi’Kmaq of Prince Edward Island in Canada and the Shinnecock Indian Nation of New York. Half of some 1,600 remaining tribe members there still occupy a more than 300-hectare territorial homeland on Long Island surrounded by multimillion-dollar Southampton mansions.
The Guna relocation is being closely watched as a possible template for other threatened communities. What sets the Guna apart from many others is that they have a place to go.
Rising sea levels in Guna Yala More than 30,000 Indigenous Guna inhabit the province now called Guna Yala, which includes the archipelago once known as San Blas and a strip of mainland. Most live on the islands, traveling back to the mainland to get water from the mouth of the river there, and in some cases to tend crops. Some of the islands sit several meters above average sea level, but the vast majority are uninhabited spits of land with palm trees, many only a meter or less above sea level.
So far, only the residents of Gardi Sugdub are included in the relocation plan. The Guna people of the islands are sustained by the biodiversity there. The sea, mangroves and nearby mainland forests provide food, medicine and building materials. The men hunt and fish to provide seafood to the best restaurants in Panama City, and agriculture remains part of the economy. Guna communities elect traditional authorities known as sailas (“chiefs” in Guna) and argars (“chief’s spokesmen”), and they hold regular meetings to address community issues.
In recent decades, the Guna have moved toward an economy based on tourism and providing services to outsiders. They earn money supplying food, souvenirs and cultural artifacts to tourists but allow visitors to the islands only with prior approval from the sailas. Outsiders are not permitted to own property or operate businesses.
Carlos Arenas is an international human rights lawyer and an adviser on social and climate justice issues. When he visited Gardi Sugdub in 2014 as a consultant for Displacement Solutions, a nonprofit initiative focused on housing, land and property rights, he was tasked to assess the nascent relocation plans and provide recommendations. He was shocked to see the visible threat posed by the rising sea. “You cannot see much elevation,” Arenas says. “The level of exposure was extremely high, but they don’t see it necessarily that way. They have been living there for more than 170 years.”
Heliodora Murphy grew up on Gardi Sugdub and has watched the ocean rise higher each year. The 52-year-old grandmother doesn’t understand those who dismiss climate change in light of the growing physical evidence all around. Murphy, also speaking through an interpreter, recalls her father bringing rocks and sand from a river on the mainland to shore up pathways and keep their home dry. Arenas says that some families face a daily struggle against the ocean. They build barriers that are immediately destroyed and have to be built again.
Some of the stopgap measures have been counterproductive, like filling in coral reefs to expand the land area. Reefs are a natural buffer against wave action, storm surges, flooding and erosion. Destroying them has only added to the peril.
Today, Murphy says, storm surges carry water into her small, ground-level home. “It’s very different than in the past,” she says. “The waves are so much higher now.” About two years ago, she decided she’d move with her family. “We can’t stay here.”
A history of autonomy Historically, the Guna have had a level of autonomy rare among Indigenous people. When the Spanish conquistadors arrived in what is now Colombia and Panama, the Guna lived primarily near the Gulf of Urabá on the northern coast of Colombia. The two groups clashed violently, prompting the Guna to abandon the coastal border area and move north into the jungle of Panama near the Caribbean. By the mid-1800s, entire villages had relocated again, this time to the San Blas archipelago.
Panama declared its independence from Spain in 1821 and became a part of Gran Colombia. Throughout the 19th century, the Guna lived independently according to their customs. That changed in 1903 when Panama broke from Colombia. The new nation attempted to assimilate the people living on the archipelago.
But having escaped Spanish rule centuries earlier and avoided Colombian authority as well, the Guna resisted Panama’s acculturation efforts. When the Guna couldn’t achieve détente through other means, they launched an armed attack against the Panamanians in February 1925.
The United States, having occupied the Panama Canal Zone since 1903, had geopolitical interests in the region and threw its support behind the Guna. That support forced the Panamanian government into a negotiated peace that allowed the Guna to continue their way of life. In 1938, the Guna islands and adjacent coastline were recognized as a semiautonomous Indigenous territory, Guna Yala. The Guna have maintained control of that territory since.
The Guna find a new home The Gardi Sugdub residents first broached the idea of relocation in 2010. “They basically ran out of room,” Oliver-Smith says.
He describes the Guna as the Indigenous people in Latin America who have been perhaps most successful in defending their cultural heritage, language and territory. They initiated the plans for resettlement and made arrangements among themselves to set aside 17 hectares of property on the mainland for these purposes. The land, within the Guna Yala territory, is near a school and health center being built by the Panamanian government. When Guna leaders approached the government, the Ministry of Housing initially promised to build 50 houses on the parcel. But it remained just that — a promise — until around 2014, when the Guna began to speak publicly about their situation. News of their predicament caught the attention of Indigenous rights organizations and eventually Displacement Solutions, which turned to Arenas and Oliver-Smith to evaluate the situation and offer recommendations about the best way forward.
Following Displacement Solutions’ first report in 2014, Panama’s Ministry of Housing agreed to build 300 houses, along with the hospital and school. But Arenas, who until the COVID-19 pandemic started had visited Guna Yala every year or so, says progress remained slow, causing the Guna to question Panama’s commitment to the relocation. The Guna leveraged support from international groups and members of the Panamanian government to get the project moving. “They were the originators of the idea of resettlement,” Oliver-Smith says. “And they kept it alive.”
Arenas estimates that roughly 200 of the 300 houses in the new community are complete. The cost for the houses, which are being paid for by the Panamanian government, exceeds $10 million, and the Inter-American Development Bank has invested $800,000 in technical assistance. The new homes will have cement floors, bamboo walls, zinc roofs, running water and full electrification.
Before plans to relocate began, many Guna had already moved to cities including Panama City and Colón for school, work or simply to have more room. Arenas expects that many more people already living in mainland Panama will likely join their families in the new community. People on other Guna Yala islands will likely have to move eventually too.
Murphy has already picked out her two-bedroom home for her small nuclear family of seven. Two daughters moved to Panama City years ago, and she hopes to see them more. But at around 40 square meters, the homes may not accommodate the typical multigenerational, double-digit Guna families. Lopez plans to stay on the island, letting the younger generations live in the family’s new home on the mainland. To ensure that the ethnic and cultural identities they fought to preserve are not lost in the move, the Guna plan to develop programs to teach traditions and culture to the resettled generations. But even on Gardi Sugdub, younger generations seem less inclined to practice the traditional customs — like making and wearing wini (vibrantly colored beads worn around the arms and legs) and molas (intricately designed fabric dresses that have become a symbol of Guna life and resistance to colonialism). Murphy began learning the craft when she was 6 years old. She spends two months constructing each ensemble, which she sells to tourists for $80.
Oliver-Smith is optimistic about the relocation plan but worries that the Panamanian government has repeated some mistakes that have doomed projects elsewhere by treating resettlement solely as a housing issue. “You don’t just pick people up and move them from point A to point B. It is a reconfiguring of a life of a people,” Oliver-Smith says. “It has political, social, economic, environmental, spiritual and cultural dimensions.”
As is often the case when Indigenous and rural communities relocate, Arenas says, the government failed to make the Guna equal participants in the design concept. “The Panamanian government is trying to build a Panama City neighborhood in the middle of a tropical forest,” he says. “They have not tried to save a single tree of this beautiful landscape…. They removed everything. They tried to flatten the land because it’s cheaper…. It’s also extremely hot there, and the building materials are hot.” This increases the risk of failure, he says, because the houses don’t match the environment.
But Murphy hopes everything will be better. The new village promises dry land and more space. And perhaps returning to the mainland the Guna occupied nearly 150 years ago will lead to a stronger connection to Guna historical culture and traditions.
Oliver-Smith says the Guna are facing the challenge of resettlement with an intact culture and language that he hopes will be a basis for maintaining cultural continuity. His time spent with the Guna has convinced him that, as disruptive and devastating as resettlement can be, the Guna relocating as a cohesive group are perhaps best equipped to emerge intact even if not unscathed.
“Carlos [Arenas] and I asked an old, retired saila if he thought resettlement would change the Guna,” he says. “He said, ‘No. Individuals may change out of choice, but our culture is eternal. It will never die.’ ”
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?”
