Heather Rendulic, whose left arm was paralyzed after a series of strokes nine years ago, picks up and holds a soup can thanks to a small electrical device implanted near her spinal cord.
Tim Betler/UPMC, University of Pittsburgh Schools of the Health Sciences
Sitting in an exam room, surrounded by doctors and scientists, Heather Rendulic opened her left hand for the first time since suffering a series of strokes nine years earlier when she was in her early 20s.
“It was an amazing feeling for me to be able to do that again,” Rendulic says. “It’s not something I ever thought was possible.”
But immediately after a surgically implanted device sent electrical pulses into her spinal cord , Rendulic could not only open her hand but also showed other marked improvements in arm mobility, researchers report February 20 in Nature Medicine . “We all started crying,” Marco Capogrosso, a neuroscientist at the University of Pittsburgh, said in a February 15 news conference. “We didn’t really expect this could work as fast as that.”
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A stroke occurs when blood supply to parts of the brain is cut off, often causing short-term or long-term issues with movement, speech and vision. Stroke is a leading, and often underappreciated, cause of paralysis; in the United States alone, 5 million people are living with some form of motor deficit due to stroke. While physical therapy can provide some improvements, no treatment exists to help these patients regain full control of their limbs — and their lives.
Strokes cause paralysis because the connection between the brain and the spinal cord is damaged; the brain tries to tell the spinal cord to move certain muscles, but the message is muddled.
So, taking advantage of techniques already existing for spinal injections of anesthetics, the team invented an electrical device that can be placed along the spinal cord to stimulate the nerves there. The stimulation “does not hurt whatsoever,” Rendulic says. “It feels like a vibration.”
By aligning the electrodes on the device with sensory nerves, “we can enhance the activation of muscles that are weakened by the stroke,” Douglas Weber, an engineer and neuroscientist at Carnegie Mellon University in Pittsburgh, said at the news conference. Pulses from these electrodes seek to amplify signals from the brain, stimulating sensory nerves that go on to activate muscles, restoring voluntary body control to patients.
Rendulic and the other patient in the study both showed improvement in mobility tasks, including drawing a spiral, opening a lock and gripping and lifting a soup can while the device was on. Treatment sessions of continuous electrical stimulation were held for four hours per day, five days a week, over 29 days, and the improvements persisted for as long as four weeks after treatment stopped. This makes the researchers optimistic that they can get even stronger results if the treatment were paired with intensive physical training, Elvira Pirondini, a neuroscientist at the University of Pittsburgh, said at the news conference.
She and the rest of the team are actively testing the device with other patients, and also exploring if pairing it with physical training can improve outcomes. The researchers are hopeful that it will be widely accessible because the surgery to implant it is minimally invasive and routine, and the value of the procedure can be clearly demonstrated, which is important to convince insurance companies to cover it.
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The treatment might not work well for patients with severe mobility impairment, says UCLA neurologist Bruce Dobkin, who was not involved with the study. But it could serve as a “new tool to try to maximize the recovery” of stroke patients with more moderate paralysis, in combination with other therapies.
For Rendulic, the proven potential of using spinal cord stimulation to treat paralysis caused by stroke gives her hope for the future. “I really hope and pray that this becomes widely available,” she says, “because I know it’s going to change so many lives.”
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A human casualty of a fictional fungal pandemic is shown in this image from the HBO series The Last of Us.
Liane Hentscher/HBO
Like so many others, I’ve been watching the HBO series The Last of Us. It’s a classic zombie apocalypse drama following Joel (played by Pedro Pascal) and Ellie (Bella Ramsey) as they make their way across the former United States (now run by a fascist government called Fedra).
I’m a big fan of zombie and other post-apocalyptic fiction. And my husband had told me how good the storyline is in the video game that inspired the series, so I was prepared for interesting storytelling. What I didn’t expect was to be so intrigued by the science behind the sci-fi.
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In the opening minutes of the series, two scientists on a fictional 1968 talk show discuss the microbes that give them pandemic nightmares. One says it’s fungi — not viruses or bacteria — that keep him awake. Especially worrisome, he says, are the fungi that control rather than kill their hosts. He gives the example of fungi that turns ants into living zombies, puppeteering the insects by flooding their brains with hallucinogens.
He goes on to warn that even though human body temperature keeps us fungus-free, that might not be true if the world got a little bit warmer. He predicts that as the thermostat climbs, a fungus that hijacks insects could mutate a gene allowing it to burrow into human brains and take control of our minds. Such a fungus could induce its human puppets to spread the fungus “by any means necessary,” he says. What’s worse, there are no preventatives, treatments or cures, nor any way to make them.
It’s a brief segment, but it had me hooked. It all sounded so chilling and … plausible . After all, fungi like ones that cause nail infections , yeast infections and ringworm already infect people.
So I consulted some experts on fungal infections to find out whether this could actually happen.
I’ve got good news and bad news.
First, the bad news.
I wanted to know if warming has spurred any fungi to mutate and become infectious. So I called Arturo Casadevall. He has been thinking about fungi and heat for a long time. He’s proposed that the need to avoid fungal infections may have provided the evolutionary pressure that drove mammals and birds to evolve warm-bloodedness ( SN: 12/3/10 ).
Most fungal species simply can’t reproduce at human body temperature (37° Celsius, or 98.6° Fahrenheit). But as the world warms, “these strains either have to die or adapt,” says Casadevall, a microbiologist who specializes in fungal infections at Johns Hopkins Bloomberg School of Public Health. That raises the possibility that fungi that now infect insects or reptiles could evolve to grow at temperatures closer to human body temperature.
At the same time, humans’ average body temperature has been falling since the 19th century, at least in high-income countries, researchers reported in eLife in 2020. One study from the United Kingdom pegs average body temperature at 36.6° C (97.9° F). And some of us are even cooler.
Fungi’s possible adaptation to higher heat and humans’ cooling body temperature are on a collision course, Casadevall says.
He and colleagues presented evidence of one such crash. Climate change may have allowed a deadly fungus called Candida auris to acclimate to human body temperatures ( SN: 7/26/19 ). A version of the fungus that could infect humans independently emerged on three continents from 2012 to 2015. “It’s not like someone took a plane a spread it. These things came out of nowhere simultaneously,” Casadevall says.
Some people argue that the planet hasn’t warmed enough to make fungi a problem, he says. “But you have to think about all the really hot days [that come with climate change]. Every really hot day is a selection event,” in which many fungi will die. But some of those fungi will have mutations that help them handle the heat. Those will survive. Their offspring may be able to survive future even hotter heat waves until human body temperature is no challenge.
Fungi that infect people are usually not picky about their hosts, Casadevall says. They will grow in soil or — if given an opportunity — in people, pets or in other animals. The reason fungi don’t infect people more often is that “the world is much colder than we are, and they have no need of us,” he says.
The second episode of The Last of Us reveals that the zombie-creating fungi initially spread through people eating contaminated flour. Then, the infected people attack and bite others, spreading the fungus.
In real life, most human infections arise from breathing in spores. But Casadevall says it’s “not implausible” that people could get infected by eating spores or by being bitten.
I also wondered exactly how a fungus could evolve in response to heat. Asiya Gusa, a fungal researcher at Duke University School of Medicine, has published one possibility.
In 2020, she and colleagues reported in the Proceedings of the National Academy of Sciences on how one fungus mutated at elevated temperature to become harder to fight.
Cryptococcus deneoformans, which already infects humans (though it’s no zombie-maker), became resistant to some antifungal drugs when grown at human body temperature. The resistance was born when mobile bits of DNA called transposons (often called jumping genes) hopped into a few genes needed for the antifungals to work.
In a follow-up study, Gusa and colleagues grew C. deneoformans at either 30° C or 37° C for 800 generations, long enough to detect multiple changes in their DNA. Fungi had no problem growing at the balmy 30° C (86° F), the temperature at which researchers typically grow fungi in the lab. But their growth slowed at the higher temperature, a sign that the fungi were under stress from the heat.
In C. deneoformans , that heat stress really got things jumping. One type of transposon accumulated a median of 12 extra copies of itself in fungi grown at body temperature. By contrast, fungi grown at 30° C tended to pick up a median of only one extra copy of the transposon. The team reported those results January 20 in PNAS . The researchers don’t yet know the effect the transposon hops might have on the fungi’s ability to infect people, cause disease or resist fungus-fighting drugs.
So yeah, the bad news is not great. Fungi are mutating in the heat and at least one species has gained the ability to infect people thanks to climate change. Other fungi that infect people are more widespread than they were in the 1950s and 1960s, also thanks to a warming world ( SN: 1/4/23 ).
But I promised good news. And here it is.
It may not be our body temperature, but our brain chemistry, that protects us from being hijacked by zombifying fungi.
I consulted Charissa de Bekker and Jui-Yu Chou, two researchers who study the Ophiocordyceps fungi that are the model for the TV show’s fungal menace. These fungi infect ants, flooding the insects with a cocktail of chemicals that steer the ants to climb plants. Once in position, the ants chomp down and the chemicals keep the jaw muscles locked in place ( SN: 7/17/19 ).
Unlike most fictional zombies, the ants are alive during this process. “A lot of people get the misconception that we work on undead ants,” says de Bekker, a microbiologist at Utrecht University in the Netherlands. She’s glad to see the show “stick to the story of the host being very much alive while its behaviors change.” The fungi even help preserve the ant, keeping it alive even while feeding on it. But eventually the ant dies. Then a mushroom rises from the corpse, showering spores onto the ground where other ants may become infected.
Related species of Ophiocordyceps infect various species of ants and other insects. But each fungal species is very specific to the host it infects. That’s because the fungi had to individualize the chemicals they use to control the particular species they infect. The ability to manipulate behavior comes at the cost of not being able to infect multiple species.
A fungus that specializes in infecting ants probably can’t get past humans’ immune systems, says Chou, a fungal researcher at the National Changhua University of Education in Taiwan. “Think of a key that fits into a specific lock. It is only this unique combination that will trigger the lock to open,” he says.
Even if the fungi evolved to withstand human body temperature and immune system attacks, they probably couldn’t take control of our minds, de Bekker says. “Manipulation is like a whole different ballgame. You need a ton of additional tools to get there.” It took millions of years of coevolution for the fungi to master piloting ants, after all.
While fungi do make mind-altering chemicals that can affect human behavior (LSD and psilocybin, for instance), Casadevall agrees that fungi that mind control insects probably won’t turn humans into zombies. “It’s not one of my worries,” he says.
Infected ants don’t turn into vicious, biting zombies either, de Bekker says. “If anything, we actually see the healthy ants being aggressive toward infected individuals, once they figure out that they’re infected, to basically get rid of them.” That “social immunity” helps protect the rest of the nest from infection.
The fictional scientist’s assertion that we couldn’t prevent, treat or cure these fungal infections is also a stretch.
Antifungal drugs exist and they cure many fungal infections, though some infections may persist. Some that spread to the brain may be particularly difficult to clear.Some fungi are also evolving resistance to the drugs. And a few fungal vaccines are in the works , although they may not be ready for years.
The experts I talked to say they hope the show will bring attention to real fungal diseases.
Gusa was especially glad to see fungi in the limelight. And she shares my fondness for that retro series opening in which the scientist predicts climate change could spawn mind-controlling fungi bent on infecting every person on the planet.
“I was pretty much yelling at the TV when I watched the [show’s] intro,” in an excited kind of way, she says. “This is the foundation of a lot of my grant funding … the threat of thermal adaptation of fungi.… To see it played out on the screen was something kind of fun.”
Tina Hesman Saey is the senior staff writer and reports on molecular biology. She has a Ph.D. in molecular genetics from Washington University in St. Louis and a master’s degree in science journalism from Boston University.
Our mission is to provide accurate, engaging news of science to the public. That mission has never been more important than it is today.
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Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education (EIN 53-0196483).
The pandemic has changed how people work, such as working late from home. That shift has prompted a global conversation on burnout, but researchers disagree on how to define and measure the syndrome. That makes evidence-based solutions hard to come by.
When New Zealand Prime Minister Jacinda Ardern, who garnered international praise for how she handled the pandemic in her country, recently announced her intention to resign , here’s how she summed up her surprise decision: “I know what the job takes, and I know that I no longer have enough in the tank to do it justice.”
Social scientists and journalists worldwide largely interpreted Ardern’s words in her January 19 speech as a reference to burnout.
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“She’s talking about an empty tank,” says Christina Maslach, a psychological researcher who has been interviewing and observing workers struggling with workplace-related distress for decades. In almost 50 years of interviews, says Maslach of the University of California, Berkeley, “that phrase [has come] up again and again and again.”
Numerous studies and media reports suggest that burnout, already high before the pandemic, has since skyrocketed worldwide, particularly among workers in certain professions, such as health care, teaching and service. The pandemic makes clear that the jobs needed for a healthy, functioning society are burning people out, Maslach says.
But disagreement over how to define and measure burnout is pervasive, with some researchers even questioning if the syndrome is simply depression by another name. Such controversy has made it difficult to estimate the prevalence of burnout or identify how to best help those who are suffering.
Here are some key questions researchers are asking to get a handle on the problem.
Some researchers argue that burnout is a strictly modern-day phenomenon, brought on by overwork and hustle culture. But others contend that burnout is merely the latest iteration of a long line of exhaustion disorders, starting with the Ancient Greek concept of acedia . This condition, wrote 5th century monk and theologian John Cassian, is marked by “bodily listlessness and yawning hunger.”
The more contemporary notion of burnout originated in the 1970s. Herbert Freudenberger, the consulting psychologist for volunteers working with drug addicts at St. Mark’s Free Clinic in New York City, used the term to describe the volunteers’ gradual loss of motivation, emotional depletion and reduced commitment to the cause.
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Roughly simultaneously, Maslach was interviewing social service workers in California and began observing similar characteristics. That prompted Maslach and her then–graduate student, Susan Jackson, now at Rutgers University in Piscataway, N.J., to develop the first tool to measure burnout, the Maslach Burnout Inventory. The duo defined burnout as comprising of three components: exhaustion, cynicism and inefficacy, or persistent feelings of low personal accomplishment.
Respondents rated statements on a scale from 0 (“never”) to 6 (“daily”). Sample statements read: “I feel emotionally drained from my work” for exhaustion; “I doubt the significance of my work” for cynicism; and “I have accomplished many worthwhile things in this job” for inefficacy. High scores for exhaustion and cynicism, and low scores for inefficacy, indicated that a person was struggling with burnout.
Maslach’s scale turned burnout into a legitimate area of inquiry, says Renzo Bianchi, an occupational health psychologist at the Norwegian University of Science and Technology in Trondheim. “Before [the Maslach Burnout Inventory], burnout was pop psychology.”
Maslach’s inventory remains the most widely used tool to study burnout. But many criticize that definition of the syndrome ( SN: 10/26/22 ).
Conceptualizing burnout as a combination of exhaustion, cynicism and inefficacy is “arbitrary,” wrote organizational psychologists Wilmar Schaufeli and Dirk Enzmann in their 1998 book, The Burnout Companion to Study and Practice: A Critical Analysis . “What would have happened if other items had been included? Most likely, other dimensions would have appeared.”
Moreover, those three components and what’s causing them are themselves poorly defined, says work and organizational psychologist Evangelia Demerouti of Eindhoven University of Technology in the Netherlands. For instance, numerous nonwork factors can trigger exhaustion, such as health problems and caregiving responsibilities.
Disagreements over what constitutes burnout, and how to measure the phenomenon, has led to a chaotic body of literature. A key point of contention is how to use Maslach’s inventory. Maslach never designated a cutoff point at which a worker tips from not burnt out to burnt out. Rather the inventory was designed as a tool to help researchers identify patterns of burnout within a given work environment or profession.
But in practice, Maslach has little control over how researchers use the inventory. A review of 182 studies on physician burnout in 45 countries reported in September 2018 in JAMA is illustrative. Almost 86 percent of studies in that review used a version of the Maslach Burnout Inventory. But roughly a quarter of those studies used unofficial versions of Maslach’s scale, such as halving the number of statements or measuring exhaustion only. Those versions are clinically invalid, Maslach contends.
Moreover, most researchers using the inventory, or a modified version, did designate cutoff scores, though teams’ definitions for high, medium and low burnout showed little agreement. Consequently, estimates for the prevalence of physician burnout varied from 0 to 80.5 percent — figures that are impossible to interpret, the researchers note.
What’s more, across all the studies, the JAMA team identified 142 definitions of burnout . And among the subset of studies not using a version of the inventory, the researchers identified 11 unique methods for measuring burnout.
Those many concerns are prompting some researchers to call for a return to the drawing board on how to define and measure burnout. That process should start with qualitative interviews to see how people struggling at work speak about their own experiences, Demerouti says. “We don’t [have] a good conceptualization and diagnosis of burnout.… We need to start from scratch.”
Surprisingly, yes. Researchers concur that exhaustion is a core feature of the syndrome, wrote Bianchi and his team in March 2021 in Clinical Psychological Science.
Research in the past two decades is also converging on the idea that burnout appears to involve changes to cognition, such as problems with memory and concentration. Those cognitive problems can take the form of people becoming forgetful — missing a recurring meeting or struggling to perform routine tasks, for instance, says Charlie Renaud, an occupational health psychologist at the University of Rennes in France. Such struggles can carry over into people’s personal lives, causing leisure activities, such as reading and watching movies, to become laborious.
As these findings mount, some researchers have begun to incorporate questions on cognitive changes into their burnout scales, Renaud says.
At first glance, the two concepts appear contradictory. Depression is typically seen as stemming from within the individual and burnout as stemming from societal forces, chiefly the workplace ( SN: 2/12/23 ). But some researchers have begun to question if burnout exists as a standalone diagnosis. The concepts are not mutually exclusive, research shows. Chronic stress in one’s environment can trigger depression and certain temperaments can make one more prone to burnout.
For instance, scoring high for the personality trait neuroticism — characterized by irritability and a tendency to worry — better predicted a person’s likelihood of experiencing burnout than certain work-related factors, such as poor supervisor support and lack of rapport with colleagues, Bianchi and his team reported in 2018 in Psychiatry Research.
Moreover, exhaustion occurred together with depression more frequently than with either cynicism or inefficacy, Bianchi and his team reported in the 2021 paper . If burnout is characterized by a suite of symptoms, then exhaustion and depression appear a more promising combination than the Maslach trifecta, the team reported.
“The real problem is that we want to believe that burnout is not a depressive condition, [or] as severe as a depressive condition,” Bianchi says. But that, he adds, simply isn’t true.
Not everyone thinks that’s a good idea. “Burnout was never, ever thought of as a clinical diagnosis,” Maslach says.
Bianchi and his team disagree. The researchers have developed their own scale, the Occupational Depression Inventory, which assesses nine core symptoms associated with major depression, including cognitive impairment and suicidal thinking, through the lens of work. For instance, instead of rating a statement like “I feel like a failure,” participants rate the statement, “My experience at work made me feel like a failure.”
If burnout is a form of depression, then it can be treated as such, Bianchi says. And, unlike burnout, treatments for depression, such as therapy and, in severe cases, medication, are already established. “Hopefully the interventions, the treatments, the forms of support that exist for depressed people can then be applied for occupational depression,” he says.
But treating the individual, while often a necessary first step, does nothing to alleviate the work-related stress that triggered the crisis, says occupational health psychologist Kirsi Ahola of the Finnish Institute of Occupational Health in Helsinki. “[Imagine] the person is on sick leave, for example, for a few weeks and recuperates and rests … and he comes back to the exactly same situation where the demands are too high and no support and whatever. Then he or she starts burning out again.” That cycle is difficult to break.
Burnout is not included in the American Psychiatric Association’s current Diagnostic and Statistical Manual. The World Health Organization adopted Maslach’s conceptualization of burnout when they outlined the syndrome in their 2019 International Classification of Diseases. Burnout constitutes “an occupational phenomenon,” not a medical condition, the agency noted.
Most researchers agree that interventions must target work-related distress at all levels, from the individual to the workplace to governing bodies.
Interventions at the individual level include therapy, exercise, developing hobbies outside of work and crafting one’s job to better fit one’s goals ( SN: 1/10/23 ). Additionally, cognitive training programs that help restore memory, attention and other cognitive deficits have shown promise in alleviating the cognitive problems associated with burnout, Renaud and University of Rennes developmental psychologist Agnès Lacroix reported January 2 in the International Journal of Stress Management.
At the workplace level, simple fixes , such as fewer video meetings and reducing distractions during the workday, can alleviate distress ( SN: 4/7/21 ). It’s time to chip away at all the little changes that have increased people’s workload over time, Maslach says. “Everybody adds stuff to people’s work. They never subtract.”
Ultimately, though, it may take systemic changes, such as more stringent labor laws, to combat burnout in countries like the United States, where sick leave is seldom guaranteed and few rules protect employees from overwork and job insecurity.
But even without regulations forcing employers’ hands, governments and companies that prioritize healthy workplaces have a competitive advantage. “When people are feeling well and cope well and have energy, they are also better workers,” Ahola says.
Sujata Gupta is the social sciences writer and is based in Burlington, Vt.
Our mission is to provide accurate, engaging news of science to the public. That mission has never been more important than it is today.
As a nonprofit news organization, we cannot do it without you.
Your support enables us to keep our content free and accessible to the next generation of scientists and engineers. Invest in quality science journalism by donating today.
Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education (EIN 53-0196483).
Some fungi (shown) are only found in association with bark beetles. These fungi break down tree chemicals and can entice invading bark beetles to burrow.
Dineshkumar Kandasamy and Veit Grabe ( CC BY 4.0 )
Fungi may help some tree-killer beetles turn a tree’s natural defense system against itself.
The Eurasian spruce bark beetle ( Ips typographus ) has massacred millions of conifers in forests across Europe. Now, research suggests that fungi associated with these bark beetles are key players in the insect’s hostile takeovers. These fungi warp the chemical defenses of host trees to create an aroma that attracts beetles to burrow , researchers report February 21 in PLOS Biology .
This fungi-made perfume might explain why bark beetles tend to swarm the same tree. As climate change makes Europe’s forests more vulnerable to insect invasions, understanding this relationship could help scientists develop new countermeasures to ward off beetle attacks.
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Bark beetles are a type of insect found around the world that feed and breed inside trees ( SN: 12/17/10 ). In recent years, several bark beetle species have aggressively attacked forests from North America to Australia, leaving ominous strands of dead trees in their wake.
But trees aren’t defenseless. Conifers — which include pine and fir trees — are veritable chemical weapons factories. The evergreen smell of Christmas trees and alpine forests comes from airborne varieties of these chemicals. But while they may smell delightful, these chemicals’ main purpose is to trap and poison invaders.
Or at least, that’s what they’re meant to do.
“Conifers are full of resin and other stuff that should do horrible things to insects,” says Jonathan Gershenzon, a chemical ecologist at the Max Planck Institute for Chemical Ecology in Jena, Germany. “But bark beetles don’t seem to mind at all.”
This ability of bark beetles to overcome the powerful defense system of conifers has led some scientists to wonder if fungi might be helping. Fungi break down compounds in their environment for food and protection ( SN: 11/30/21 ). And some type of fungi — including some species in the genus Grosmannia — are always found in association with Eurasian spruce bark beetles.
Gershenzon and his colleagues compared the chemicals released by spruce bark infested with Grosmannia and other fungi to the chemical profile of uninfected trees. The presence of the fungi fundamentally changed the chemical profile of spruce trees, the team found. More than half the airborne chemicals — made by fungi breaking down monoterpenes and other chemicals that are likely part of the tree defense system — were unique to infected trees after 12 days.
This is surprising because researchers had previously assumed that invading fungi hardly changed the chemical profile of trees, says Jonathan Cale, a fungal ecologist at the University of Northern British Columbia in Prince George, Canada, who was not involved with the research.
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Later experiments revealed that bark beetles can detect many of these fungi-made chemicals. The team tested this by attaching tiny electrodes on bark beetles’ heads and detecting electrical activity when the chemicals wafted passed their antennae. What’s more, the smell of these chemicals combined with beetle pheromones led the insects to burrow at higher rates than the smell of pheromones alone.
The study suggests that these fungi-made chemicals can help beetles tell where to feed and breed, possibly by advertising that the fungi has taken down some of the tree’s defenses. The attractive nature of the chemicals could also explain the beetle’s swarming behavior, which drives the death of healthy adult trees.
But while the fungi aroma might doom trees, it could also lead to the beetles’ demise. Beetle traps in Europe currently use only beetle pheromones to attract their victims. Combining pheromones with fungi-derived chemicals might be the secret to entice more beetles into traps, making them more effective.
The results present “an exciting direction for developing new tools to manage destructive bark beetle outbreaks” for other beetle species as well, Cale says. In North America, mild winters and drought have put conifer forests at greater risk from mountain pine beetle ( Dendroctonus pendersoae ) attacks. Finding and using fungi-derived chemicals might be one way to fend off the worst of the bark beetle invasions in years to come.
Freda Kreier was a fall 2021 intern at Science News . She holds a bachelor’s degree in molecular biology from Colorado College and a master’s in science communication from the University of California, Santa Cruz.
Our mission is to provide accurate, engaging news of science to the public. That mission has never been more important than it is today.
As a nonprofit news organization, we cannot do it without you.
Your support enables us to keep our content free and accessible to the next generation of scientists and engineers. Invest in quality science journalism by donating today.
Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education (EIN 53-0196483).
To demonstrate a new milestone in quantum computer error correction, scientists made improvements to the quantum bits of Google’s quantum chip, Sycamore (two versions shown, with the newer generation on the right).
To shrink error rates in quantum computers, sometimes more is better. More qubits, that is.
The quantum bits, or qubits, that make up a quantum computer are prone to mistakes that could render a calculation useless if not corrected. To reduce that error rate, scientists aim to build a computer that can correct its own errors. Such a machine would combine the powers of multiple fallible qubits into one improved qubit, called a “logical qubit,” that can be used to make calculations ( SN: 6/22/20 ).
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Future quantum computers could solve problems impossible for even the most powerful traditional computers ( SN: 6/29/17 ). To build those mighty quantum machines, researchers agree that they’ll need to use error correction to dramatically shrink error rates. While scientists have previously demonstrated that they can detect and correct simple errors in small-scale quantum computers, error correction is still in its early stages ( SN: 10/4/21 ).
The new advance doesn’t mean researchers are ready to build a fully error-corrected quantum computer, “however, it does demonstrate that it is indeed possible, that error correction fundamentally works,” physicist Julian Kelly of Google Quantum AI said in a news briefing February 21.
Logical qubits store information redundantly in multiple physical qubits. That redundancy allows a quantum computer to check if any mistakes have cropped up and fix them on the fly. Ideally, the larger the logical qubit, the smaller the error rate should be. But if the original qubits are too faulty, adding in more of them will cause more problems than it solves.
Using Google’s Sycamore quantum chip, the researchers studied two different sizes of logical qubits, one consisting of 17 qubits and the other of 49 qubits. After making steady improvements to the performance of the original physical qubits that make up the device, the researchers tallied up the errors that still slipped through. The larger logical qubit had a lower error rate, about 2.9 percent per round of error correction, compared to the smaller logical qubit’s rate of about 3.0 percent, the researchers found.
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That small improvement suggests scientists are finally tiptoeing into the regime where error correction can begin to squelch errors by scaling up. “It’s a major goal to achieve,” says physicist Andreas Wallraff of ETH Zurich, who was not involved with the research.
However, the result is only on the cusp of showing that error correction improves as scientists scale up. A computer simulation of the quantum computer’s performance suggests that, if the logical qubit’s size were increased even more, its error rate would actually get worse. Additional improvement to the original faulty qubits will be needed to enable scientists to really capitalize on the benefits of error correction.
Still, milestones in quantum computation are so difficult to achieve that they’re treated like pole jumping, Wallraff says. You just aim to barely clear the bar.
Physics writer Emily Conover has a Ph.D. in physics from the University of Chicago. She is a two-time winner of the D.C. Science Writers’ Association Newsbrief award.
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These images from the James Webb Space Telescope zoom in on six bright, red, extremely distant galaxies that appear to be too massive to exist.
I. Labbé/Swinburne University of Technology, CSA, ESA, NASA. Image processing: G. Brammer/Niels Bohr Institute’s Cosmic Dawn Center/University of Copenhagen
The James Webb Space Telescope’s first peek at the distant universe unveiled galaxies that appear too big to exist.
Six galaxies that formed in the universe’s first 700 million years seem to be up to 100 times more massive than standard cosmological theories predict, astronomer Ivo Labbé and colleagues report February 22 in Nature . “Adding up the stars in those galaxies, it would exceed the total amount of mass available in the universe at that time,” says Labbé, of the Swinburne University of Technology in Melbourne, Australia. “So you know that something is afoot.”
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The telescope, also called JWST, released its first view of the early cosmos in July 2022 ( SN: 7/11/22 ). Within days, Labbé and his colleagues had spotted about a dozen objects that looked particularly bright and red, a sign that they could be massive and far away.
“They stand out immediately, you see them as soon as you look at these images,” says astrophysicist Erica Nelson of the University of Colorado Boulder.
Measuring the amount of light each object emits in various wavelengths can give astronomers an idea of how far away each galaxy is, and how many stars it must have to emit all that light. Six of the objects that Nelson, Labbé and colleagues identified look like their light comes from no later than about 700 million years after the Big Bang. Those galaxies appear to hold up to 10 billion times the mass of our sun in stars. One of them might contain the mass of 100 billion suns.
“You shouldn’t have had time to make things that have as many stars as the Milky Way that fast,” Nelson says. Our galaxy contains about 60 billion suns’ worth of stars — and it’s had more than 13 billion years to grow them. “It’s just crazy that these things seem to exist.”
In the standard theories of cosmology, matter in the universe clumped together slowly, with small structures gradually merging to form larger ones. “If there are all these massive galaxies at early times, that’s just not happening,” Nelson says.
One possible explanation is that there’s another, unknown way to form galaxies, Labbé says. “It seems like there’s a channel that’s a fast track, and the fast track creates monsters.”
But it could also be that some of these galaxies host supermassive black holes in their cores, says astronomer Emma Curtis-Lake of the University of Hertfordshire in England, who was not part of the new study. What looks like starlight could instead be light from the gas and dust those black holes are devouring. JWST has already seen a candidate for an active supermassive black hole even earlier in the universe’s history than these galaxies are, she says, so it’s not impossible.
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Finding a lot of supermassive black holes at such an early era would also be challenging to explain ( SN: 3/16/18 ). But it wouldn’t require rewriting the standard model of cosmology the way extra-massive galaxies would.
“The formation and growth of black holes at these early times is really not well understood,” she says. “There’s not a tension with cosmology there, just new physics to be understood of how they can form and grow, and we just never had the data before.”
To know for sure what these distant objects are, Curtis-Lake says, astronomers need to confirm the galaxies’ distances and masses using spectra , more precise measurements of the galaxies’ light across many wavelengths ( SN: 12/16/22 ).
JWST has taken spectra for a few of these galaxies already, and more should be coming, Labbé says. “With luck, a year from now, we’ll know a lot more.”
Lisa Grossman is the astronomy writer. She has a degree in astronomy from Cornell University and a graduate certificate in science writing from University of California, Santa Cruz. She lives near Boston.
Our mission is to provide accurate, engaging news of science to the public. That mission has never been more important than it is today.
As a nonprofit news organization, we cannot do it without you.
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Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education (EIN 53-0196483).
