Homo sapiens who reached Europe around 54,000 years ago introduced bows and arrows to that continent, a new study suggests.
Researchers examined tiny triangular stone points and other artifacts excavated at a rock-shelter in southern France called Grotte Mandrin. H. sapiens on the move probably brought archery techniques from Africa to Europe, archaeologist Laure Metz of Aix-Marseille University in France and colleagues report February 22 in Science Advances.
“Metz and colleagues demonstrate bow hunting [at Grotte Mandrin] as convincingly as possible without being caught bow-in-hand,” says archaeologist Marlize Lombard of the University of Johannesburg, who did not participate in the new study. No bows were found at the site. Wooden items such as bows preserve poorly. The oldest intact bows, found in northern European bogs, date to around 11,000 years ago, Metz says.
Previous stone and bone point discoveries suggest that bow-and-arrow hunting originated in Africa between about 80,000 and 60,000 years ago. And previously recovered fossil teeth indicate that H. sapiens visited Grotte Mandrin as early as 56,800 years ago, well before Neandertals’ demise around 40,000 years ago and much earlier than researchers had thought that H. sapiens first reached Europe (SN: 2/9/22).
“We’ve shown that the earliest known Homo sapiens to migrate into Neandertal territories had mastered the use of the bow,” Metz says.
No evidence suggests that Neandertals already present in Europe at that time launched arrows at prey. It’s also unclear whether archery provided any substantial hunting advantages to H. sapiens relative to spears that were thrust or thrown by Neandertals. Among 852 stone artifacts excavated in a H. sapiens sediment layer at Grotte Mandrin dated to about 54,000 years ago, 196 triangular stone points displayed high-impact damage. Another 15 stone points showed signs of both high-impact damage and alterations caused by butchery activities, such as cutting.
Comparisons of those finds were made to damage on stone replicas of the artifacts that the researchers used as arrowheads shot from bows and as the tips of spears inserted in handheld throwing devices. Additional comparative evidence came from stone and bone arrowheads used by recent and present-day hunting groups.
Impact damage along the edges of stone points from the French site indicated that these implements had been attached at the bottom to shafts.
The smallest Grotte Mandrin points, many with a maximum width of no more than 10 millimeters, could have pierced animals’ hides only when shot from bows as the business ends of arrows, the researchers say. Experiments they conducted with replicas of the ancient stone points found that stone points less than 10 millimeters wide reach effective hunting speeds only when attached to arrow shafts propelled by a bow.
Larger stone points, some of them several times the size of the smaller points, could have been arrowheads or might have tipped spears that were thrown or thrust by hand or launched from handheld spear throwers, the researchers conclude.
Lombard, the University of Johannesburg archaeologist, suspects that the first H. sapiens at the French rock-shelter hunted with bows and arrows as well as with spears, depending on where and what they were hunting. Earlier studies directed by Lombard indicated that sub-Saharan Africans similarly alternated between these two types of hunting weapons starting between about 70,000 and 58,000 years ago.
H. sapiens newcomers to Europe may have learned from Neandertals that spear hunting in large groups takes precedence on frigid landscapes, where bow strings can easily snap and long-distance pursuit of prey is not energy efficient, Lombard says.
But learning about archery from H. sapiens may not have been in the cards for Neandertals. Based on prior analyses of brain impressions on the inside surfaces of fossil skulls, Lombard suspects that Neandertals’ brains did not enable the enhanced visual and spatial abilities that H. sapiens exploited to hunt with bows and arrows.
That’s a possibility, though other controversial evidence suggests that Neandertals behaved no differently from Stone Age H. sapiens (SN: 3/26/20).If Grotte Mandrin Neandertals never hunted with bows and arrows but still survived just fine alongside H. sapiens archers for roughly 14,000 years, reasons for Neandertals’ ultimate demise remain as mysterious as ever.
Whether it’s Katy Perry poaching dancers from once-BFF Taylor Swift or Clytemnestra orchestrating the murder of her husband Agamemnon, betrayal is a dark, persistent part of the human condition. Unlike garden-variety deception, betrayal happens in established relationships, destroying trust that has developed over time. It’s usually unexpected, and it yields a unique, often irreparable, wound. In fact, betrayers have a special place in hell, literarily: In Dante’s Inferno, they occupy the ninth and final circle; mere fraudsters dwell in the eighth.
While most of us are familiar with betrayal, investigating it is really hard. (Consider all the complications of a study that asks people in trusted relationships to betray each other.) Case studies of real betrayals can provide insight after-the-fact, but without a time machine, finding studies that reveal big picture patterns about the lead-up to treachery are scarce.
“We all know betrayal exists,” says Cristian Danescu-Niculescu-Mizil, a computer scientist at Cornell University who spends a lot of time thinking about what language reveals about relationships. “But finding relevant data is really hard.”
So when Danescu-Niculescu-Mizil heard about a Diplomacy, a strategy game rife with betrayal, he figured it might serve as a good proxy for real life treachery. And he was right: Studying the patterns of communication between the players revealed that betrayal is sometimes foreseeable. But like many relationships that collapse in betrayal, teasing out what goes wrong and who is at fault isn’t so easy. Unlike Risk and other war games, Diplomacy is all about, well, diplomacy (John F. Kennedy and Henry Kissinger reportedly were fans). Set in Europe before World War I, the nations/players have to form alliances to win. But chance is removed from the equation; players don’t roll dice or take turns. There’s only diplomacy: a negotiation phase where players converse, form alliances and gather intelligence (these days, typically online), and a movement phase where everyone’s decisions are revealed and executed all at once. Betrayal is so integral to Diplomacy that, as noted on a “This American Life” episode, stabbing an ally in the back is referred to by the shorthand “stabbing.”
Danescu-Niculescu-Mizil, colleague and fan-of-the-game Jordan Boyd-Graber, and colleagues examined 249 games of Diplomacy with a total of 145,000 messages among players. When they used a computer program to compare exchanges between players whose relationships ended in betrayal with those whose relationships lasted, the computer discerned subtle signals of impending betrayal.
One harbinger was a shift in politeness. Players who were excessively polite in general were more likely to betray, and people who were suddenly more polite were more likely to become victims of betrayal, study coauthor and Cornell graduate student Vlad Niculae reportedJuly 29 at the Annual Meeting of the Association for Computational Linguistics in Beijing. Consider this exchange from one round:
Germany: Can I suggest you move your armies east and then I will support you? Then next year you move [there] and dismantle Turkey. I will deal with England and France, you take out Italy.
Austria: Sounds like a perfect plan! Happy to follow through. And—thank you Bruder!
Austria’s next move was invading German territory. Bam! Betrayal.
An increase planning-related language by the soon-to-be victim also indicated impending betrayal, a signal that emerges a few rounds before the treachery ensues. And correspondence of soon-to-be betrayers had an uptick in positive sentiment in the lead-up to their breach. Working from these linguistic cues, a computer program could peg future betrayal 57 percent of the time. That might not sound like much, but it was better than the accuracy of the human players, who never saw it coming. And remember that by definition, a betrayer conceals the intention to betray; the breach is unexpected (that whole trust thing). Given that inherent deceit, 57 percent isn’t so bad.
When I spoke to Danescu-Niculescu-Mizil, he said that more important than the clues themselves is the shift in the balance of behavior in the relationship. Positive or negative sentiment of one player isn’t what matters, it’s the asymmetry of the behavior of the two people in the relationship. He likens the linguistic tells to body language: While you wouldn’t use it as a sole basis for decision-making, if you know how to interpret it, it might give you an advantage.
More work is needed to explore whether these patterns exist in real life. And while the research did reveal some patterns, it can’t say anything about cause and effect or who is at fault. Perhaps, for example, the extensive planning of the eventual victims came off as super bossy and frustrating to the eventual betrayer. After all, Clytemnestra’s betrayal of Agamemnon came after he killed their daughter Iphigenia. That kind of bad blood may be unforgivable.
Particles of twisted light that have been entangled using quantum mechanics offer a new approach to dense and secure data storage.
Holograms that produce 3-D images and serve as security features on credit cards are usually made with patterns laid down with beams of laser light. In recent years, physicists have found ways to create holograms with entangled photons instead. Now there is, literally, a new twist to the technology.
Entangled photons that travel in corkscrew paths have resulted in holograms that offer the possibility of dense and ultrasecure data encryption, researchers report in a study to appear in Physical Review Letters. Light can move in a variety of ways, including the up-and-down and side-to-side patterns of polarized light. But when it carries a type of rotation known as orbital angular momentum, it can also propagate in spirals that resemble twisted rotini pasta.
Like any other photons, the twisted versions can be entangled so that they essentially act as one entity. Something that affects one of an entangled photon pair instantly affects the other, even if they are very far apart.
In previous experiments, researchers have sent data through the air in entangled pairs of twisted photons (SN: 8/5/15). The approach should allow high-speed data transmission because light can come with different amounts of twist, with each twist serving as a different channel of communication.
Now the same approach has been applied to record data in holograms. Instead of transmitting information on multiple, twisted light channels, photon pairs with different amounts of twist create distinct sets of data in a single hologram. The more orbital angular momentum states involved, each with different amounts of twist, the more data researchers can pack into a hologram.
In addition to cramming more data into holograms, increasing the variety of twists used to record the data boosts security. Anyone who wants to read the information out needs to know, or guess, how the light that recorded it was twisted.
For a hologram relying on two types of twist, says physicist Xiangdong Zhang of the Beijing Institute of Technology, you would have to pick the right combination of the twists from about 80 possibilities to decode the data. Bumping that up to combinations of seven distinct twists leads to millions of possibilities. That, Zhang says, “should be enough to ensure our quantum holographic encryption system has enough security level.” The researchers demonstrated their technique by encoding words and letters in holograms and reading the data back out again with twisted light. Although the researchers produced images from the holographic data, says physicist Hugo Defienne of the Paris Institute of Nanosciences, the storage itself should not be confused with holographic images.
Defienne, who was not involved with the new research, says that other quantum holography schemes, such as his efforts with polarized photons, produce direct images of objects including microscopic structures.
“[Their] idea there is very different . . . from our approach in this sense,” Defrienne says. “They’re using holography to store information,” rather than creating the familiar 3-D images that most people associate with holograms.
The twisted light data storage that Zhang and his colleagues demonstrated is slow, requiring nearly 20 minutes to decode an image of the acronym “BIT,” for the Beijing Institute of Technology where the experiments were performed. And the security that the researchers have demonstrated is still relatively low because they included only up to six forms of twisted light in their experiments.
Zhang is confident that both limitations can be overcome with technical improvements. “We think that our technology has potential application in quantum information encryption,” he says, “especially quantum image encryption.”
The existing boundaries of national parks and other habitat preserves aren’t enough to protect more than three-quarters of the world’s well-studied insects.
The finding, reported February 1 in One Earth, shows that people who design nature preserves “don’t really think about insects that much,” says coauthor Shawan Chowdhury, an ecologist at the German Centre for Integrative Biodiversity Research in Leipzig.
That’s a problem because insect populations around the globe are plummeting, a growing body of research suggests, probably due to climate change and human development (SN: 4/26/22). For instance, insect abundance in Puerto Rico has dropped by up to 98 percent over the last 35 years. Threats to insect survival could have ripple effects on plants and other animals. Insects help form the foundation for many ecosystems: They pollinate around 80 percent of all plant species and serve as a staple in the diets of hundreds of thousands of animals (and the occasional carnivorous plant).
One way to avert insect extinctions is to set aside the land they need to survive. But scientists know the ranges for only about 100,000 of the estimated 5.5 million insect species. To determine how well existing protected areas may be aiding insect conservation, Chowdhury and colleagues mapped the known habitats of about 89,000 of those species and compared the ranges with the boundaries of preserves from the World Database on Protected Areas.
Overall, these spaces don’t safeguard enough habitat for 67,384 insect species — about 76 percent of the species included in the study — the team found. Roughly 2 percent of species do not overlap with protected areas at all.
Conserving insects, Chowdhury says, will mean setting aside more insect-friendly spaces in the years ahead.
Earth’s inner core may have temporarily stopped rotating relative to the mantle and surface, researchers report in the January 23 Nature Geoscience. Now, the direction of the inner core’s rotation may be reversing — part of what could be a roughly 70-year-long cycle that may influence the length of Earth’s days and its magnetic field — though some researchers are skeptical.
“We see strong evidence that the inner core has been rotating faster than the surface, [but] by around 2009 it nearly stopped,” says geophysicist Xiaodong Song of Peking University in Beijing. “Now it is gradually mov[ing] in the opposite direction.” Such a profound turnaround might sound bizarre, but Earth is volatile (SN: 1/13/21). Bore through the ever-shifting crust and you’ll enter the titanic mantle, where behemoth masses of rock flow viscously over spans of millions of years, sometimes upwelling to excoriate the overlying crust (SN: 1/11/17, SN: 3/2/17, SN: 2/4/21). Delve deeper and you’ll reach Earth’s liquid outer core. Here, circulating currents of molten metals conjure our planet’s magnetic field (SN: 9/4/15). And at the heart of that melt, you’ll find a revolving, solid metal ball about 70 percent as wide as the moon.
This is the inner core (SN: 1/28/19). Studies have suggested that this solid heart may rotate within the liquid outer core, compelled by the outer core’s magnetic torque. Researchers have also argued the mantle’s immense gravitational pull may apply an erratic brake on the inner core’s rotation, causing it to oscillate.
Evidence for the inner core’s fluctuating rotation first emerged in 1996. Geophysicist Paul Richards of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, N.Y., and Song, then also at Lamont-Doherty, reported that over a span of three decades, seismic waves from earthquakes took different amounts of time to traverse Earth’s solid heart.
The researchers inferred that the inner core rotates at a different speed than the mantle and crust, causing the time differences. The planet spins roughly 360 degrees in a day. Based on their calculations, the researchers estimated that the inner core, on average, rotates about 1 degree per year faster than the rest of Earth.
But other researchers have questioned that conclusion, some suggesting that the core spins slower than Song and Richards’ estimate or doesn’t spin differently at all.
In the new study, while analyzing global seismic data stretching back to the 1990s, Song and geophysicist Yi Yang — also at Peking University — made a surprising observation. Before 2009, seismic waves generated by sequences and pairs of repeating earthquakes — known as multiplets and doublets — traveled at different rates through the inner core. This indicated the waves from recurring quakes were crossing different parts of the inner core, and that the inner core was rotating at a different pace than the rest of Earth, aligning with Song’s previous research.
But around 2009, the differences in travel times vanished. That suggested the inner core had ceased rotating with respect to the mantle and crust, Yang says. After 2009, these differences returned, but the researchers inferred that the waves were crossing parts of the inner core that suggested it was now rotating in the opposite direction relative to the rest of Earth.
The researchers then pored over records of Alaskan earthquake doublets dating to 1964. While the inner core appeared to rotate steadily for most of that time, it seems to have made another reversal in rotation in the early 1970s, the researchers say.
Song and Yang infer that the inner core may oscillate with a roughly 70-year periodicity — switching directions every 35 years or so. Because the inner core is gravitationally linked to the mantle and magnetically linked to the outer core, the researchers say these oscillations could explain known 60- to 70-year variations in the length of Earth’s days and the behavior of the planet’s magnetic field. However, more work is needed to pin down what mechanisms might be responsible.
But not all researchers are on board. Yang and Song “identif[y] this recent 10-year period [that] has less activity than before, and I think that’s probably reliable,” says geophysicist John Vidale of the University of Southern California in Los Angeles, who was not involved in the research. But beyond that, Vidale says, things get contentious.
In 2022, he and a colleague reported that seismic waves from nuclear tests show the inner core may reverse its rotation every three years or so. Meanwhile, other researchers have proposed that the inner core isn’t moving at all. Instead, they say, changes to the shape of the inner core’s surface could explain the differences in wave travel times.
Future observations will probably help disentangle the discrepancies between these studies, Vidale says. For now, he’s unruffled by the purported chthonic standstill. “In all likelihood, it’s irrelevant to life on the surface, but we don’t actually know what’s happening,” he says. “It’s incumbent on us to figure it out.”
For some ant queens, the secret to long life might be a self-produced insulin blocker.
Ant queens are famously long-lived, even though they shouldn’t be. Generally, animals that put lots of energy into reproduction sacrifice some time off their life. But ant queens produce millions of eggs and live an extraordinarily long time compared with worker ants that don’t reproduce.
Now, researchers have shown how one ant species pulls off this anti-aging feat. When queens and wannabe queens of the species Harpegnathos saltator gear up to reproduce, a part of what’s called the insulin signaling pathway gets blocked, slowing aging, the researchers report in the Sept. 2 Science. That molecular pathway has long been implicated in aging in mammals, including humans. “There’s been a need to understand why queens, or reproductives, in social insects can live for so amazingly long,” says Marc Tatar, a biologist at Brown University in Providence, R.I., who was not involved with the study. Some ant species have queens that survive 30 times as long as their workers. Other social insects such as bees and termites also have long-lived queens.
In a rare behavior for ants, when a queen H. saltator dies, some female workers begin competing in duels for the chance to replace her (SN: 1/17/14). These hopeful royals develop ovaries, start laying eggs and transition into queenlike forms called gamergates. When a worker transitions to a gamergate, her life span becomes five times as long as it was. But if she doesn’t end up becoming queen and reverts back to a worker, her life span shortens again.
The researchers exploited this behavior to investigate the molecular underpinnings of anti-aging in these ants. H. saltator gamergates, it turns out, extend their life spans by taking advantage of a split in the insulin signaling pathway, the chain of chemical reactions that drive insulin’s effects on the body. One branch of this pathway is involved with reproduction, while the other is implicated in aging.
“Insulin comes with our life — [after] we eat, we have high insulin,” says Hua Yan, a biologist at the University of Florida in Gainesville. “But a constant high level of insulin is bad for longevity.”
Examining patterns of gene activity, Yan and colleagues found that gamergates have more active insulin genes than regular worker ants and, as a result, have increased metabolic activity and ovary development. But the secret sauce protecting the ants from the insulin’s aging effects appears to be a molecule called Imp-L2, which blocks the branch of the insulin pathway linked to aging, experiments showed. The branch involved in reproduction, however, remains active.
“What we don’t understand is how Imp-L2 can act on one aspect of the pathway and not on the other,” says study coauthor Claude Desplan, a developmental biologist at New York University.
These results represent a leap forward in our understanding of extreme social insect longevity, the researchers say, while also showcasing an anti-aging evolutionary adaptation that hasn’t been seen in the wild before.
For some ant queens, the secret to long life might be a self-produced insulin blocker.
Ant queens are famously long-lived, even though they shouldn’t be. Generally, animals that put lots of energy into reproduction sacrifice some time off their life. But ant queens produce millions of eggs and live an extraordinarily long time compared with worker ants that don’t reproduce.
Now, researchers have shown how one ant species pulls off this anti-aging feat. When queens and wannabe queens of the species Harpegnathos saltator gear up to reproduce, a part of what’s called the insulin signaling pathway gets blocked, slowing aging, the researchers report in the Sept. 2 Science. That molecular pathway has long been implicated in aging in mammals, including humans. “There’s been a need to understand why queens, or reproductives, in social insects can live for so amazingly long,” says Marc Tatar, a biologist at Brown University in Providence, R.I., who was not involved with the study. Some ant species have queens that survive 30 times as long as their workers. Other social insects such as bees and termites also have long-lived queens.
In a rare behavior for ants, when a queen H. saltator dies, some female workers begin competing in duels for the chance to replace her (SN: 1/17/14). These hopeful royals develop ovaries, start laying eggs and transition into queenlike forms called gamergates. When a worker transitions to a gamergate, her life span becomes five times as long as it was. But if she doesn’t end up becoming queen and reverts back to a worker, her life span shortens again.
The researchers exploited this behavior to investigate the molecular underpinnings of anti-aging in these ants. H. saltator gamergates, it turns out, extend their life spans by taking advantage of a split in the insulin signaling pathway, the chain of chemical reactions that drive insulin’s effects on the body. One branch of this pathway is involved with reproduction, while the other is implicated in aging.
“Insulin comes with our life — [after] we eat, we have high insulin,” says Hua Yan, a biologist at the University of Florida in Gainesville. “But a constant high level of insulin is bad for longevity.”
Examining patterns of gene activity, Yan and colleagues found that gamergates have more active insulin genes than regular worker ants and, as a result, have increased metabolic activity and ovary development. But the secret sauce protecting the ants from the insulin’s aging effects appears to be a molecule called Imp-L2, which blocks the branch of the insulin pathway linked to aging, experiments showed. The branch involved in reproduction, however, remains active.
“What we don’t understand is how Imp-L2 can act on one aspect of the pathway and not on the other,” says study coauthor Claude Desplan, a developmental biologist at New York University.
These results represent a leap forward in our understanding of extreme social insect longevity, the researchers say, while also showcasing an anti-aging evolutionary adaptation that hasn’t been seen in the wild before.
The Milky Way: An Autobiography of Our Galaxy takes a tour of our home in the cosmos from an unexpected perspective. Astrophysicist and folklorist Moiya McTier presents herself not as the author, but as the lucky human vessel through which the Milky Way has chosen to tell its story. Then she lets the galaxy take it away, with humor, heart and a huge dose of snark.
The book alternates chapters between science and mythology, reflecting McTier’s dual specialties (her bio says she was the first student in Harvard University’s history to study both). “Many of you don’t realize this, but myths were some of your species’ first attempt at scientific inquiry,” the Milky Way tells us.
The Milky Way is telling its story now because it’s sick of being ignored. Once upon a time, humans looked to the glittering smudge of stars in the sky for insight into when to plant crops or avoid floods. We told stories about the Milky Way’s importance in the origin and fate of the world.
Our galaxy ate it up: For an entity that spends most of its time ripping up smaller galaxies and watching its own stars die, “your stories made me feel loved and needed and, perhaps for the first time in my long existence, more helpful than I was ruinous.” But in the last few centuries, technology and light pollution have pulled humankind away. “At first, I thought it was just a phase,” the Milky Way says. “Then I remembered … that several hundred years is actually a long time for humans.” So the Milky Way decided to remind us why it’s so important. Its autobiography covers big-picture scientific questions about galaxies, like where they come from (“When a gas cloud loves itself very much,” the Milky Way explains, “it hugs itself extra tight, and after a few hundred million years, a baby galaxy is born. Leave the storks out of it, please.”). It also gets into what galaxies are made of, how they interact with other galaxies, and how they live and die. The book then zooms out to cover the origins and possible ends of the universe, mysteries like dark matter and dark energy, and even humankind’s search for other intelligent life (SN: 8/4/20).
The author takes pains to explain scientific jargon and the technical tools that astronomers use to study the sky. A lot of popular astronomy writing glosses over how astronomers think about cosmic distance or exactly what a spectrum is, but not this book. If you’ve ever been curious about these insider details, The Milky Way has you covered.
McTier’s version of our home galaxy is heavily anthropomorphized. The Milky Way is brash, vain and arrogant in a way that may hide a secret insecurity. Its central black hole is characterized as the physical embodiment of the galaxy’s shame and regrets, a source of deep existential angst. And its relationship with the Andromeda galaxy is like a long-term, long-distance romance, with each galaxy sending stars back and forth as love notes until the two can eventually merge (SN: 3/05/21).
This could have felt gimmicky. But McTier’s efforts to make the metaphors work while keeping the science accurate and up-to-date made the premise endearing and entertaining.
I laughed twice on Page 1. I learned a new word on Page 2. I dog-eared the endnotes early on because it became instantly clear I would want to read every one. I read this book while traveling in rural upstate New York, where the sky is much clearer than at my home outside of Boston. The Milky Way reminded me to look up and appreciate my home in the universe, just like its narrator wanted.
For millions of people, COVID-19 doesn’t end with a negative test. Weeks or months after traces of the virus disappear from noses and throats, symptoms can persist or come back. New ones might pop up and stick around for months. People suffering from long COVID are unwillingly in it for the long haul — and it’s still unclear who’s at the highest risk for the condition.
Researchers don’t yet have an official definition for long COVID, and its symptoms are wide-ranging (SN: 7/29/22). Some people struggle with extreme fatigue that interferes with their daily lives. Others can’t concentrate or struggle with memory amid thick brain fog. Still others have organ damage or a persistent cough and difficulty breathing. “There are a variety of different kinds of ways that people can have long COVID. It’s not just the one thing,” says Leora Horwitz, an internal medicine physician at New York University Langone Health. “That’s what makes it so hard to study.”
This spectrum of symptoms makes pinning down who’s at high risk for long-term health problems from the disease especially hard. Some post-COVID conditions may stem from virus-induced damage or from the stress of being hospitalized with severe disease. In other cases, the body’s own immune response to the virus could drive the damage. Or the virus may be hiding somewhere in the body, possibly the gut, helping symptoms to persist (SN: 11/24/20). Different causes may have different risk groups, says Hannah Davis, cofounder of the Patient-Led Research Collaborative, a research and advocacy group studying long COVID.
There are some broad hints about who’s at risk. Studies suggest that women are more likely than men to have lingering symptoms. COVID-19 patients with more than five symptoms in the first week of infection or preexisting health conditions such as asthma may be more likely to develop long COVID. Age also appears to be a risk factor, though results are mixed regarding whether the burden falls on older people or middle-aged people. Populations that were disproportionally hit by COVID-19 overall — including Black and Hispanic people — may similarly face disparities for long COVID. And while vaccination seems to protect people from developing long COVID, Horwitz says, it’s still unclear by how much.
Age is a risk factor for severe COVID-19, and the U.S. Centers for Disease Control and Prevention lists more than 30 health problems, including cancer and lung disease, that also raise the risk. “So many researchers assume that those [risk factors] will be the same for long COVID and there’s no scientific basis for that,” Davis says. There are many more that researchers could be missing when it comes to long COVID.
Using health records and exams, and knowledge of ailments with symptoms similar to long COVID, experts are on the hunt for those risk factors.
Examining health When it comes to getting a better handle on who’s at risk for long COVID — which also goes by the wonky alias Post-Acute Sequelae of SARS-CoV-2 infection — electronic health records may hold important clues.
Horwitz is part of the U.S. National Institutes of Health’s RECOVER initiative that aims to understand the long-term impacts of COVID-19. One arm of the study involves mining millions of electronic health records to find potential patterns.
Studying millions of these records should pinpoint potential risk factors that are rare in the population overall but perhaps more common for people with long COVID, Horwitz says. “That’s hard even in a cohort study of thousands.”
But health records aren’t perfect: They depend on physicians logging that patients are having trouble sleeping or focusing, or that they’re exhausted. “The things people are complaining about, we’re really bad at writing down those diagnoses on the record,” Horwitz says. “So we miss that.” To account for health records’ deficiencies, Horwitz and colleagues are also directly studying thousands of people. Participants answer a questionnaire every three months so that the team can identify what kinds of symptoms people have and whether they’re getting better or worse.
Then blood, urine, stool and saliva samples can reveal what’s happening in the body. Tests on those samples can uncover if the coronavirus is still around and causing trouble, or if the immune system has learned to attack the body itself. Participants with abnormal test results will undergo additional, targeted testing.
“Unlike electronic health records where it’s hit or miss, like somebody might have had a CAT scan or might not, here we say, ‘OK, you have trouble breathing. We will take a look at your lungs,’” Horwitz says.
The study includes a range of participants: adults and kids, pregnant people, those currently with COVID-19 and people who died after having the disease.
Some of the potential risk factors that the team is looking for include autoimmune diseases and other viral infections. The list may grow as more people join the study. “We’re trying to balance the fishing versus making sure that we’re at least fishing for things that could be in the water,” Horwitz says.
Among short supply, though, are people who never caught the virus — important “controls” to highlight what’s different about people who got COVID-19.
So far, more than 7,000 people have signed up, and the group plans to recruit around 10,000 more. It’s a lot of data, but early results may soon start coming in.
“We’ll probably try to do an interim peek at those data this fall,” Horwitz says. “It’s tricky because we deliberately wanted to enroll 18,000 people so we would have enough power to really look at the things we care about. I don’t want to cheat and look too early, but we also know that there’s a lot of interest.”
Striking similarities Some long COVID symptoms — brain fog, fatigue and trouble sleeping — mirror another illness: myalgic encephalomyelitis/chronic fatigue syndrome, or ME/CFS. Other long COVID symptoms, such as rapid heartbeat and dizziness, fall in the category of nervous system disorders called dysautonomia. Similar symptoms could belie similar risk factors.
Yet potential risk factors for those conditions are largely missing from long COVID research, says Davis, who has had long COVID since March 2020. Among the possibilities that scientists are considering are things like Epstein-Barr virus, migraines and some autoimmune diseases.
Epstein-Barr virus could be a big one, Davis says. Infections last a lifetime because the virus can go into hiding in the body and possibly reemerge. That virus has been linked to ME/CFS for decades, though its role in the disease remains unclear, Davis says. Some early hints of a link between Epstein-Barr virus and long COVID already exist. Multiple studies have found evidence in blood samples from some long COVID patients that the immune system recently battled with Epstein-Barr virus, which can cause infectious mononucleosis, a disease characterized by extreme fatigue. Other studies have found signs of the virus itself. And in 2021, Davis and colleagues found that 40 out of 580 people with symptoms of long COVID who responded to an online survey reported having a current or recent Epstein-Barr virus infection.
With ME/CFS, it’s possible that another illness caused by a different virus triggers the Epstein-Barr virus, which then causes the fatigue syndrome. Given the parallels between that condition and long COVID, some scientists are wondering if the two are actually the same disease, with the coronavirus now known as one trigger.
Examining health conditions that raise the chances of long COVID could provide answers for both diseases, says Nancy Klimas, an immunologist at Nova Southeastern University in Fort Lauderdale, Fla. That’s in part because researchers can more easily identify people who developed lingering symptoms after a bout of COVID-19 compared with unknown infections that may precede ME/CFS.
Also, “there’s a huge difference in these two fields and it’s money,” Klimas says. She now has funding from the CDC to compare long COVID patients with people who have ME/CFS. The team hopes that physical exams and specialized tests will reveal whether the two diseases are indeed the same and be a step toward understanding the mechanisms behind the lingering symptoms.
Still, since long COVID as a whole encompasses such a wide range of symptoms, it will take time to uncover who is at risk of what.
If COVID-19 were just one disease impacting the lungs, heart or brain, the research might be easier, Horwitz says. “But we have to test everything.”
As Tanina Agosto went through her normal morning routine in July 2007, she realized something was wrong. The 29-year-old couldn’t control her left side, even her face. “Literally the top of my head to the bottom of my foot on the left side of my body could not feel anything.”
The next day, Agosto spoke with a doctor at the New York City hospital where she works as a medical secretary. He told her that she probably had a pinched nerve and to see a chiropractor.
But chiropractic care didn’t help. Months later, Agosto needed a cane to get around, and moving her left leg and arm required lots of concentration. She couldn’t work. Numbness and tingling made cooking and cleaning difficult. It felt a bit like looping a rubber band tightly around a finger until it loses sensation, Agosto says. Once the rubber band comes off, the finger tingles for a bit. But for her, the tingling wouldn’t stop.
Finally, she recalls, one chiropractor told her, “I’m not too big of a person to say there’s something very wrong with you, and I don’t know what it is. You need to see a neurologist.” In November 2008, tests confirmed that Agosto had multiple sclerosis. Her immune system was attacking her brain and spinal cord.
Agosto knew nothing about MS except that a friend of her mother’s had it. “At the time, I was like, there’s no way I’ve got this old lady’s condition,” she says. “To be hit with that and know that there’s no cure — that was just devastating.”
Why people develop the autoimmune disorder has been a long-standing question. Studies have pointed to certain gene variations and environmental factors. For decades, a common virus called Epstein-Barr virus has also been high on the list of culprits.
Now recent studies paint a clearer picture that Epstein-Barr virus instigates MS when the central nervous system gets caught in the cross hairs of an immune response to the virus’s attack. This recognition opens new options for treatment, or even vaccines. Perhaps therapies that target Epstein-Barr itself — or remove the cells in the body where the virus camps out — could jettison the virus before damage is done. Vaccines might one day “make multiple sclerosis become a historical disease like polio,” says Lawrence Steinman, a neurologist at Stanford University. “The trials will be arduous,” Steinman says. Still, “I think we might be able to put MS in the rearview mirror.”
For now, there’s a lot to learn, including how exactly the virus triggers MS, says Francesca Aloisi, a neuroscientist at the Italian National Institute of Health in Rome.
For many people with MS, even with current therapies, the disease can progress. Right now, Agosto’s symptoms are largely under control. Thanks to physical therapy, an anti-inflammatory diet and medication, she has about 90 percent function on the left side of her body. “Things like long-distance running are out of the question,” she says. Carrying grocery bags with her left arm is a challenge.
Studying the virus’s role in MS “will be an amazing game changer,” says Agosto, who is a patient advocate with the National Multiple Sclerosis Society’s New York City chapter. If Epstein-Barr virus is driving her disease, she wants to know: “How do we get this virus out of the driver’s seat?”
A familiar virus Multiple sclerosis is an uncommon disease, affecting nearly 3 million people globally. Yet Epstein-Barr virus is almost everywhere.
The virus, discovered in 1964, infects an estimated 90 percent of people around the world. People infected as young children might have a mild cold or show no symptoms. Teenagers or young adults may experience a bout of debilitating fatigue called infectious mononucleosis, or mono, that can last weeks or months.
These symptoms eventually fade. But Epstein-Barr infections hang on. The virus belongs to the herpesvirus family — a group known for instigating lifelong infections. The herpesviruses behind cold sores, genital herpes and chicken pox also stick around for life, usually staying quiet for long stretches. For example, varicella-zoster virus, which causes chicken pox, goes latent inside nerve cells but can resurface to cause the painful disease shingles (SN: 3/2/19, p. 22).
In the body, Epstein-Barr virus slips into the epithelial cells that line the surface of the throat, allowing the virus to spread to other people via saliva — hence mono’s nickname, “the kissing disease.” The virus also infects a type of immune cell called B cells, where it enters viral hibernation.
Epstein-Barr virus can cause problems long after the initial infection. People who had mono are more likely to develop cancers such as Hodgkin’s lymphoma than people who didn’t. And they are more likely to be diagnosed with MS. A teenage case of mono doesn’t mean long-term problems are inevitable. But avoiding mono-related fatigue doesn’t guarantee an escape from risk either. Agosto, for instance, doesn’t recall ever having mono. Establishing the link In March 2000, epidemiologist Alberto Ascherio of the Harvard T.H. Chan School of Public Health published research exploring the link between Epstein-Barr virus and MS. With colleague Mette Munch of the University of Aarhus in Denmark, Ascherio analyzed data from eight studies suggesting that MS patients are more likely to have had an Epstein-Barr infection than those without MS. Studies over the next 20 years continued to hint that the virus plays a role, but “the problem is to go from a suggestion or suspicion to proof,” says Ascherio. Getting that proof is difficult, because nearly everyone has been infected with Epstein-Barr virus, or EBV, yet very few have MS.
“If it’s true that EBV causes MS, then you would expect to find that those individuals who are not infected with EBV, they will not get MS,” Ascherio says. “It’s very simple.” He and colleagues needed to follow a large group of young adults who had never been infected.
The researchers found such a group in the U.S. military. Through the Department of Defense Serum Repository, the team had access to repeated blood samples from more than 10 million individuals, taken when active-duty members were screened for diseases such as HIV at the start of their service and then every two years. Using blood samples taken between 1993 and 2013, Ascherio and colleagues could identify people who had never been infected with Epstein-Barr virus, track new infections and learn when people who developed MS started showing symptoms.
Over that 20-year span, 801 people whose blood was tested were diagnosed with MS. Thirty-five of those people had no signs of Epstein-Barr virus infection in their first blood sample. But all but one became infected before their MS diagnosis. People infected with the virus were 32 times as likely to develop MS as uninfected people. What’s more, the researchers found that blood concentrations of a nervous system protein that is a signal of nerve damage rose after Epstein-Barr virus infection, before an MS diagnosis. The results prompted Ascherio and his team to make a bold claim in Science in January: “These findings cannot be explained by any known risk factor for MS and suggest EBV as the leading cause of MS.”
It is still possible that infection with Epstein-Barr virus is a time stamp for something else, perhaps not yet identified, that’s also relevant for MS, says Mark Allegretta, vice president of research at the National Multiple Sclerosis Society. “The way we talk about it now is that it’s very strong evidence that it’s necessary for development of MS, but it’s insufficient on its own.”
Ascherio isn’t deterred. “After 20 years of talking about EBV and MS, it’s quite exciting that we’ve finally nailed it down,” he says. “There was a lot of skepticism until now and that is fading away.” A skeptic convinced The fact that Epstein-Barr virus is implicated in so many diseases had many researchers skeptical of its link to MS, says Tobias Lanz, a neurologist at Stanford University. “It’s involved in tumors, it’s involved in MS, it’s involved in lupus, it’s in chronic fatigue syndrome. Somehow, people link it to everything and that makes us reasonably suspicious.”
Lanz’s mentor, Stanford rheumatologist William Robinson, was one of those skeptics. Once Lanz, Robinson and their colleagues found hints of how Epstein-Barr virus could spark nerve damage, however, Robinson became a believer.
The team discovered that immune proteins called antibodies from some MS patients attach to a key Epstein-Barr virus protein, as well as to a protein from the central nervous system. This finding, described in the March 10 Nature, suggests that as the immune system learns how to recognize the virus, it may also learn to attack nerve cells.
The viral protein, called EBNA1, helps Epstein-Barr virus persist in the body for life, hidden away inside B cells. Its molecular twin in the central nervous system, a portion of a protein called GlialCAM, is so similar that antibodies for the virus recognize and bind tightly to it too, the team found in lab experiments.
“That really changed everything,” Robinson says, calling it “an in-your-face result that you can’t dismiss as not being real.” In addition to adding to the evidence that Epstein-Barr virus causes MS, the finding also provides a hint of a possible mechanism: GlialCAM is found in glial cells, which support nerve cells and form the insulating layer myelin that helps nerve cells send signals (SN: 8/22/15, p. 18). Myelin is the very thing that is destroyed in MS.
About a quarter of patients in the study had antibodies that recognize both EBNA1 and GlialCAM. The similarities between the two proteins, called molecular mimicry, means that EBNA1 may not be a good viral protein to include in vaccines to curb diseases related to Epstein-Barr virus, says Steinman, the Stanford neurologist, who was also involved with the research. If the virus indeed sparks an autoimmune reaction, vaccines that target this viral protein or other mimics could harm myelin and spur MS. Viral damage Several studies support the idea that molecular mimicry causes MS damage. But other hypotheses are on the table.
Those B cells, for instance, where Epstein-Barr viruses hide out, produce antibodies. One possibility is that B cells infected with Epstein-Barr virus transform in ways that encourage the immune system to attack the body’s own tissues.
Aloisi, the neuroscientist in Rome, backs a different hypothesis: Perhaps the immune system’s attack on the virus itself is behind the damage.
“The biology of the virus is so similar to the biology of the disease,” Aloisi says. For some people, MS can go through phases of silence where the disease is stable, no better, no worse. The disease then reactivates, producing new brain lesions and worsening symptoms. Epstein-Barr virus can similarly come out of latency, perhaps causing a surge of problems before returning to hibernation inside host cells.
In 2007, Aloisi and colleagues discovered unexpected clusters of B cells within the membranes that cover and protect the brain. In all but one of 22 patients studied, some of those B cells were infected with Epstein-Barr virus.
The finding “was like a bomb in the field,” Aloisi says, “because nobody ever thought about this possibility.” Other researchers initially failed to replicate the results. But “little by little other work came out [in support],” she says. “It’s difficult to find these [clusters of B cells] in the brain because people with MS don’t have large, inflamed brains. It’s small spots here and there.”
It’s possible that the central nervous system becomes a stronghold for the virus, Aloisi says. Immune cells called T cells, which can either coordinate an attack or kill infected cells, rush in. Some virus-infected B cells die, but the immune system can’t eliminate the virus. Myelin gets caught in the cross fire. “This creates a situation that is extremely detrimental to the tissue,” she says. Treatment tactics Regardless of whether Epstein-Barr virus drives MS symptoms directly or causes the body’s immune response to go haywire, the big question is what to do about it.
One obvious path is to develop MS drugs that go after the virus, Aloisi says. Some drugs that block hepatitis B virus and HIV have shown potential against Epstein-Barr virus in lab-grown cells, says Ascherio, the Harvard epidemiologist. But those results are very preliminary.
Another option is to go after the infected cells. A few MS therapies may do that already. The existing MS therapy natalizumab already prevents B and T cells from crossing into the central nervous system. Fingolimod may do that as well. Another drug called ocrelizumab, approved for patients with MS in 2017, is an antibody that attaches to a protein on B cells and triggers cell death. The drug helps patients, like Agosto, who have relapsing-remitting MS, but it’s less effective for people with a progressive form of the disease, who have fewer treatment options (SN: 12/9/17, p. 20).
Researchers thought the drug dampened faulty immune responses by depleting B cells, Lanz says. “But it could also well be that we’re hitting those particular pathogenic B cells that are infected with Epstein-Barr virus. So the B cell depletion might actually be an anti-EBV drug and nobody appreciated that.”
Aloisi agrees. “Now we need something that targets the EBV-infected cells, not all of the B cells,” she says. Indiscriminately killing B cells puts patients at risk for other infections. One way to get around that could come in the form of T cell therapies that go after only infected cells. Such therapies are already in clinical trials in MS patients.
Some researchers suspect that antiviral treatments would probably make the most sense when used early on, before the immune system eats away at the myelin around the nerve cells. Once the virus has kick-started an immune response to attack the nervous system, “the train may already be out of the station,” says neuroimmunologist Emily Harrington of Ohio State University’s Wexner Medical Center in Columbus.
A vaccine Even better than stopping the infection once it starts would be to build defenses before the virus invades, or to stop it from reawakening. Enter vaccines.
The widespread impact of mono and Epstein-Barr virus’s links to cancer and autoimmune disease had already spurred vaccine research, so a few potential shots are already in the pipeline. But Epstein-Barr virus has a complex way of invading the body, says vaccinologist Javier Gordon Ogembo of City of Hope, a cancer care center in Duarte, Calif. The virus uses at least five viral proteins to invade both epithelial cells and B cells. A vaccine would need to drive an immune response that blocks the virus’s entry into both cell types to prevent infection. “This is the reason, I think, why there has not been a vaccine so far,” Ogembo says. Pharmaceutical company GlaxoSmithKline took one vaccine candidate to clinical trials in the early 2000s. It seemed to stop people from developing mono, but it didn’t meet the original goal of preventing infection overall. So the company abandoned the vaccine.
Moderna, the biotechnology company made famous for its effective COVID-19 vaccine, recently launched a clinical trial of an mRNA vaccine for Epstein-Barr virus. The shot teaches the body to recognize four of the five viral proteins that help the virus invade both cell types, says viral immunologist Katherine Luzuriaga of the University of Massachusetts Chan Medical School in Worcester, who is involved in the trial. For now, the team is testing whether the vaccine sparks a strong immune response and getting a sense for whether it might curb cases of mono.
In March, the U.S National Institutes of Health launched a clinical trial to test a vaccine that uses nanoparticles to teach the body to recognize the virus and get rid of it. Ogembo and colleagues at City of Hope are developing another vaccine that uses a modified virus as the immune system’s instructor.
Although clinical trials could reveal within the next few years whether the vaccines can control mono, it will be decades before researchers learn anything about the potential impact on cancer or MS, Luzuriaga and Ogembo say. The hope is to see an outcome like the vaccines for human papillomaviruses, Luzuriaga says, which reduce the number of HPV infections and led to a dramatic reduction in cervical cancers.
Developing therapeutic vaccines for people who already have MS may also be possible, Ascherio says. The aim would be to stop the virus from emerging from its slumber inside B cells. It would be akin to the shingles vaccine, which prevents the painful reactivation of varicella-zoster virus in nerve cells.
That is Steinman’s aim as well, but he envisions a shot that would put a check on the undesirable immune response. Steinman and colleagues have tested such a vaccine to try and teach MS patients’ immune systems to ignore and not harm a protein called myelin basic protein, which helps add myelin to nerves. There were hints the vaccine might have been effective, but the team ultimately stopped the project.
“If it weren’t for other very powerful therapies becoming approved in that same time frame, we may have continued,” Steinman says. Now, he wants to make a vaccine that helps MS patients tolerate, rather than attack, the central nervous system protein GlialCAM.
Researchers at BioNTech, also famous for developing a COVID-19 vaccine, are working on something similar. In mice with a disease close to MS, the company showed that an mRNA vaccine could keep the immune system from attacking myelin proteins, the team reported in January 2021 in Science.
Time will tell how effective any of these shots might be. But with studies providing more and more evidence that Epstein-Barr virus is linked to many diseases, Ogembo says, “it’s time to make a vaccine and get rid of it.”
The one-of-a-kind pattern of ridges and valleys in a fingerprint may not only betray who was present at a crime scene. It may also tattle about what outlawed drugs a suspect handled.
With advanced spectroscopy, researchers can detect and measure tiny flecks of cocaine, methamphetamine and heroin — in some cases as little as trillionths of a gram — on a lone fingerprint. The study, led by researchers at the National Institute of Standards and Technology in Gaithersburg, Md., appears May 7 in Analytical Chemistry. Using an ink-jet–printed array of known quantities of drugs, researchers calibrated their spectroscopy techniques to measure specks of the chemicals. Then, using a 3-D printed plastic finger and a synthetic version of finger oil, researchers created drug-tainted fingerprints pressed onto paper or silicon.
On paper, the researchers detected as little as 1 nanogram of cocaine and amounts above 50 nanograms of methamphetamine and heroin. On silicon, the method picked up as little as 8 picograms of cocaine and heroin and around 1 nanogram of methamphetamine.
Researchers could also point to the location of the drugs on the fingerprint— at the peaks or dips of the pattern, for instance. Such information, the authors say, could help investigators finger what chemicals a suspect handled first and help corroborate a timeline of events in a crime.
