Surprisingly simple measures might keep domestic cats from killing a lot of wildlife.
Estimates vary, but it’s likely that billions of birds and mammals succumb each year to our outdoor-ranging feline friends (SN: 1/29/13). Calls to keep cats indoors are often contentious among cat owners, and cats can sometimes reject colorful collars or loud bells designed to make them more noticeable.
Interventions that reduce cat predation and have buy-in from cat owners “are so important because we’re just decimating bird populations,” says Susan Willson, an ecologist at St. Lawrence University in Canton, N.Y., who wasn’t involved in the study. While preliminary, she says this study shows that “simply feeding your cat a high-meat diet might actually work.”
Most attempts to curb cats’ impact on wildlife have focused on restricting cat behavior and their ability to hunt. But Robbie McDonald, an ecologist at the University of Exeter in Cornwall, England, and his colleagues investigated the root of the problem: the urge to go out hunting in the first place. “We wanted to find out why well-fed cats might still kill wildlife,” he says.
The team reasoned this urge might stem from natural instincts to hunt, or from a need for cats to supplement their diet. Cats are carnivores, and some cat foods might not be meeting all a cat’s needs, McDonald says. If either of these influence hunting behavior, then perhaps beefing up the amount of meat in a cat’s diet or mimicking hunting behavior through play could fulfill those needs without the collateral damage to wildlife.
McDonald and his colleagues tested these new interventions on 355 domestic cats in 219 households in England’s southwest. Only known hunters were enrolled, and owners first tallied up every bird, mammal or other critter their cats brought home for seven weeks, to establish a baseline for each cat.
Owners then implemented one of a handful of interventions for six weeks: switching to a grain-free, high-meat commercially available food; playing for five to 10 minutes each day; putting their cat’s normal food in a puzzle feeder; and existing methods like bells or Birdsbesafe collars. Some owners didn’t change anything, but continued tracking their cats.
Cats fed the meat-rich diet brought home 36 percent less prey, on average, than they did before the diet change, the team calculated. For instance, a cat that normally brings home a daily catch would instead return about 20 critters a month. “This might not seem like very much,” McDonald says of the drop. But “a very large cat population means that if this average were applied across the board, it would result in very many millions fewer deaths.”
Felines treated to playtime, which consisted of owners getting their cats to stalk, chase and pounce on a feather toy and then giving cats a mouse toy to bite, returned 25 percent less prey, though that drop came mostly from mammals, not birds. Cats that started using puzzle feeders actually brought home more wildlife. Bells had no discernible effect, while cats fitted with Birdsbesafe collars brought home 42 percent fewer birds, but roughly the same number of mammals, which aligns with previous research.
“We were surprised diet change had such a strong effect,” McDonald says, in part because the cat’s pretreatment diets were all variable. “Nutrition seems to have some bearing on a cat’s tendency to kill things and some cats that hunt may need something extra” that’s provided by a meatier diet, he says. McDonald is already working to pinpoint what that extra something might be.
“It’s a robust study that I hope is followed up with more research,” says Willson, the St. Lawrence ecologist. Because the study focused on prey brought home, it could be missing wildlife killed and eaten or left outside, she says.
The surest way to prevent cats from killing wildlife is to keep them indoors, McDonald says. While many cat owners care about wildlife, they also resist such restrictions as unnatural for their cat. But McDonald found these new interventions were less controversial. After the trial, 33 percent of participants reported they planned to continue feeding their cats meat-rich diets, and 76 percent reported they’d play more with their cats.
“We hope that owners of cats who hunt consider trying these changes,” McDonald says. “It’s good for conservation and good for cats.”
Gertrude the pig rooted around a straw-filled pen, oblivious to the cameras and onlookers — and the 1,024 electrodes eavesdropping on her brain signals. Each time the pig’s snout found a treat in a researcher’s hand, a musical jingle sounded, indicating activity in her snout-controlling nerve cells.
Those beeps were part of the big reveal on August 28 by Elon Musk’s company Neuralink. “In a lot of ways, it’s kind of like a Fitbit in your skull with tiny wires,” said Musk, founder of Tesla and SpaceX, of the new technology.
Neuroscientists have been recording nerve cell activity from animals for decades. But the ambitions of Musk and others to link humans with computers are shocking in their reach. Future-minded entrepreneurs and researchers aim to listen in on our brains and perhaps even reshape thinking. Imagine being able to beckon our Teslas with our minds, Jedi-style.
Some scientists called Gertrude’s introduction a slick publicity stunt, full of unachievable promises. But Musk has surprised people before. “You can’t argue with a guy who built his own electric car and sent it to orbit around Mars,” says Christof Koch, a neuroscientist at the Allen Institute for Brain Science in Seattle.
Whenever Gertrude’s snout touched something, nerve cells in her brain fired electrical signals detected by an implanted device (signals shown as wavy lines on black). Similar technology may one day help people with paralysis or brain disorders.Neuralink
Whether Neuralink will eventually merge brains and Teslas is beside the point. Musk isn’t the only dreamer chasing neurotechnology. Advances are coming quickly and span a variety of approaches, including external headsets that may be able to distinguish between hunger and boredom; implanted electrodes that translate intentions to speak into real words; and bracelets that use nerve impulses for typing without a keyboard.
Today, paralyzed people are already testing brain-computer interfaces, a technology that connects brains to the digital world (SN: 11/16/13, p. 22). With brain signals alone, users have been able to shop online, communicate and even use a prosthetic arm to sip from a cup (SN: 6/16/12, p. 5). The ability to hear neural chatter, understand it and perhaps even modify it could change and improve people’s lives in ways that go well beyond medical treatments. But these abilities also raise questions about who gets access to our brains and for what purposes.
Readers’ thoughts
We asked members of the public for their take on the ethics of new brain technology. A sampling of their quotes are on the following pages.
“The thoughts of someone accessing a person’s brain is absolutely terrifying.”
“I have no wish/desire to be a zombie or a clone.”
Because of neurotechnology’s potential for both good and bad, we all have a stake in shaping how it’s created and, ultimately, how it is used. But most people don’t have the chance to weigh in, and only find out about these advances after they’re a fait accompli. So we asked Science News readers their views about recent neurotechnology advances. We described three main ethical issues — fairness, autonomy and privacy. Far and away, readers were most concerned about privacy.
The idea of allowing companies, or governments, or even health care workers access to the brain’s inner workings spooked many respondents. Such an intrusion would be the most important breach in a world where privacy is already rare. “My brain is the only place I know is truly my own,” one reader wrote.
Technology that can change your brain — nudge it to think or behave in certain ways — is especially worrisome to many of our readers. A nightmare scenario raised by several respondents: We turn into zombies controlled by others.
When these types of brain manipulations get discussed, several sci-fi scenarios come to mind, such as memories being wiped clean in the poignant 2004 film Eternal Sunshine of the Spotless Mind; ideas implanted into a person’s mind, as in the 2010 movie Inception; or people being tricked into thinking a virtual world is the real thing, as in the mind-bending 1999 thriller The Matrix.
Today’s tech capabilities are nowhere near any of those fantasies. Still, “the here and now is just as interesting … and just as morally problematic,” says neuroethicist Timothy Brown of the University of Washington in Seattle. “We don’t need The Matrix to get our dystopia.”
The ability to nudge brain activity in certain directions raises ethical questions.Julia Yellow
Today, codes of ethics and laws govern research, medical treatments and certain aspects of our privacy. But we have no comprehensive way to handle the privacy violations that might arise with future advances in brain science. “We are all flying by the seat of our pants here,” says Rafael Yuste, a neurobiologist at Columbia University.
For now, ethics questions are being taken up in a piecemeal way. Academic researchers, bioethicists and scientists at private companies, such as IBM and Facebook, are discussing these questions among themselves. Large brain-research consortiums, such as the U.S. BRAIN Initiative (SN: 2/22/14, p. 16), include funding for projects that address privacy concerns. Some governments, including Chile’s national legislature, are starting to address concerns raised by neurotechnology.
With such disjointed efforts, it’s no surprise that no consensus has surfaced. The few answers that exist are as varied as the people doing the asking.
Electrode bracelet
A bracelet studded with electrodes can detect tiny nerve impulses on the wrist. The bracelet (shown) uses electromyography, which picks up the behavior of nerve cells that control muscles, to eavesdrop on signals that move from the brain to hand muscles. Developed by New York City–based CTRL-Labs, a neural interface company acquired by Facebook Reality Labs in 2019, the bracelet allows users to play chess in a virtual room, control a hand avatar and type with tiny movements from inside a pocket, for instance, without a keyboard, mouse or touch screen. The technology is still in development.
CTRL-Labs
Reading thoughts
The ability to pull information directly from the brain — without relying on speaking, writing or typing — has long been a goal for researchers and doctors intent on helping people whose bodies can no longer move or speak. Already, implanted electrodes can record signals from the movement areas of the brain, allowing people to control robotic prostheses.
In January 2019, researchers at Johns Hopkins University implanted electrodes in the brain of Robert “Buz” Chmielewski, who was left quadriplegic after a surfing accident. With signals from both sides of his brain, Chmielewski controlled two prosthetic arms to use a fork and a knife simultaneously to feed himself, researchers announced in a press release on December 10.
Robert “Buz” Chmielewski, who has had quadriplegia since his teens, uses brain signals to feed himself some cake. Via electrodes implanted in both sides of his brain, he controls two robotic arms: One manipulates the knife and the other holds the fork.
Other research has decoded speech from the brain signals of a paralyzed man who is unable to speak. When the man saw the question, “Would you like some water?” on a computer screen, he responded with the text message, “No, I am not thirsty,” using only signals in his brain. This feat, described November 19 at a symposium hosted by Columbia University, is another example of the tremendous progress under way in linking brains to computers.
“Never before have we been able to get that kind of information without interacting with the periphery of your body, that you had to voluntarily activate,” says Karen Rommelfanger, a neuroethicist at Emory University in Atlanta. Speaking, sign language and writing, for instance, “all require several steps of your decision making,” she says.
Today, efforts to extract information from the brain generally require bulky equipment, intense computing power and, most importantly, a willing participant, Rommelfanger says. For now, an attempt to break into your mind could easily be thwarted by closing your eyes, or wiggling fingers, or even getting drowsy.
What’s more, Rommelfanger says, “I don’t believe that any neuroscientist knows what a mind is or what a thought is,” she says. “I am not concerned about mind reading, from the existing terrain of technologies.”
But that terrain may change quickly. “We are getting very, very close” to having the ability to pull private information from people’s brains, Yuste says, pointing to studies that have decoded what a person is looking at and what words they hear. Scientists from Kernel, a neurotech company near Los Angeles, have invented a helmet, just now hitting the market, that is essentially a portable brain scanner that can pick up activity in certain brain areas.
For now, companies have only our behavior — our likes, our clicks, our purchase histories — to build eerily accurate profiles of us and estimate what we’ll do next. And we let them. Predictive algorithms make good guesses, but guesses all the same. “With this neural data gleaned from neurotechnology, it may not be a guess anymore,” Yuste says. Companies will have the real thing, straight from the source.
Even subconscious thoughts might be revealed with further technological improvements, Yuste says. “That is the ultimate privacy fear, because what else is left?”
Laser helmets
A helmet sends laser beams through the skull and into the brain. After bouncing off tissue and blood, the particles of light return to detectors that measure oxygen levels. Those levels indicate where in the brain nerve cells are active, thus giving clues about mental processes. This technology, called functional near-infrared spectroscopy, is the same that allows pulse oximeters to measure oxygen levels in the blood. In early 2021, the neurotechnology company Kernel, based near Los Angeles, began selling Kernel Flow helmets (shown) to researchers who are using the tools to study concussions, language and even dreaming.
Kernel
Rewrite, revise
Technology that can change the brain’s activity already exists today, as medical treatments. These tools can detect and stave off a seizure in a person with epilepsy, for instance, or stop a tremor before it takes hold.
Researchers are testing systems for obsessive-compulsive disorder, addiction and depression (SN: 2/16/19, p. 22). But the power to precisely change a functioning brain directly — and as a result, a person’s behavior — raises worrisome questions.
The desire to persuade, to change a person’s mind, is not new, says Marcello Ienca, a bioethicist at ETH Zurich. Winning hearts and minds is at the core of advertising and politics. Technology capable of changing your brain’s activity with just a subtle nudge, however, “brings current manipulation risks to the next level,” Ienca says.
“Imagine walking into McDonald’s and suddenly you have an irresistible urge for a cheeseburger (or 10).”
What happens if such influence finds a place outside the medical arena? A doctor might use precise brain-modifying technology to ease anorexia’s grip on a young person, but the same might be used for money-making purposes: “Imagine walking into McDonald’s and suddenly you have an irresistible urge for a cheeseburger (or 10),” one of our readers wrote.
Is the craving caused by real hunger? Or is it the result of a tiny neural nudge just as you drove near the golden arches? That neural intrusion could spark uncertainty over where that urge came from, or perhaps even escape notice altogether. “This is super dangerous,” Yuste says. “The minute you start stimulating the brain, you are going to be changing people’s minds, and they will never know about it, because they will interpret it as ‘that’s me.’ ”
Precise brain control of people is not possible with existing technology. But in a hint of what may be possible, scientists have already created visions inside mouse brains (SN: 8/17/19, p. 10). Using a technique called optogenetics to stimulate small groups of nerve cells, researchers made mice “see” lines that weren’t there. Those mice behaved exactly as if their eyes had actually seen the lines, says Yuste, whose research group performed some of these experiments. “Puppets,” he calls them.
Once researchers or companies can change our brain activity, will neural privacy require special protections? Julia Yellow
What to do?
As neurotechnology marches ahead, scientists, ethicists, companies and governments are looking for answers on how, or even whether, to regulate brain technology. For now, those answers depend entirely on who is asked. And they come against a backdrop of increasingly invasive technology that we’ve become surprisingly comfortable with.
We allow our smartphones to monitor where we go, what time we fall asleep and even whether we’ve washed our hands for a full 20 seconds. Couple that with the digital breadcrumbs we actively share about the diets we try, the shows we binge and the tweets we love, and our lives are an open book.
Those details are more powerful than brain data, says Anna Wexler, an ethicist at the University of Pennsylvania. “My e-mail address, my notes app and my search engine history are more reflective of who I am as a person — my identity — than our neural data may ever be,” she says.
“How would we know that what we thought or felt came from our own brains, or whether it was put there by someone else?”
It’s too early to worry about privacy invasions from neurotechnology, Wexler argues, a position that makes her an outlier. “Most of my colleagues would tell me I’m crazy.”
At the other end of the spectrum, some researchers, including Yuste, have proposed strict regulations around privacy that would treat a person’s neural data like their organs. Much like a liver can’t be taken out of a body without approval for medical purposes, neural data shouldn’t be removed either. That viewpoint has found purchase in Chile, which is now considering whether to classify neural data with new protections that would not allow companies to get at it.
Other experts fall somewhere in the middle. Ienca, for example, doesn’t want to see restrictions on personal freedom. People ought to have the choice to sell or give away their brain data for a product they like, or even for straight up cash. “The human brain is becoming a new asset,” Ienca says, something that can generate profit for companies eager to mine the data. He calls it “neurocapitalism.”
What would you like to tell the scientists working in this area? Send your thoughts to [email protected].
And Ienca is fine with that. If a person is adequately informed — granted, a questionable if — then they are within their rights to sell their data, or exchange it for a service or product, he says. People ought to have the freedom to do what they like with their information.
General rules, checklists and regulations are not likely to be a good path forward, Rommelfanger says. “Right now, there are over 20 frameworks, guidelines, principles that have been developed since 2014 on how to handle neuroscience,” she says. Those often cover “mental privacy” and “cognitive liberty,” the freedom to control your own mental life.
Those guidelines are thoughtful, she says, but the technologies differ in what they’re capable of, and in their possible ethical repurcussions. One-size-fits-all solutions don’t exist, Rommelfanger says.
Under-skull implants
Thin tendrils laced with hundreds or thousands of electrodes will spread out in the brain to listen in on — and perhaps even stimulate — nerve cells. So far, Elon Musk’s company Neuralink, based in Fremont, Calif., has tried the method on rats and pigs in the lab. Other labs are testing implanted electrodes in people with paralysis. To make the surgery less risky and more efficient, Neuralink is building a robot that can quickly sew the electrode threads (shown attached to a charging disk) into the brain, ultimately linking people with computers.
Neuralink
Instead, each company or research group may need to work through ethical issues throughout the development process. She and colleagues have recently proposed five questions that researchers can ask themselves to begin thinking about these ethical issues, including privacy and autonomy. The questions ask people to consider how new technology might be used outside of a lab, for instance.
Moving forward on the technology to help people with mental illness and paralysis is an ethical imperative, Rommelfanger says. “More than my fear of a privacy violation, my fear is about diminished public trust that could undermine all of the good this technology could do.”
A lack of ethical clarity is unlikely to slow the pace of the coming neurotech rush. But thoughtful consideration of the ethics could help shape the trajectory of what’s to come, and help protect what makes us most human.
Good news for the ozone layer: After a recent spike in CFC-11 pollution, emissions of this ozone-destroying chemical are on the decline.
Emissions of trichlorofluoromethane, or CFC-11, were supposed to taper off after the Montreal Protocol banned CFC-11 production in 2010 (SN: 7/7/90). But 2014 to 2017 saw an unexpected bump. About half of that illegal pollution was pegged to eastern China (SN: 5/22/19). Now, atmospheric data show that global CFC-11 emissions in 2019 were back down to the average levels seen from 2008 to 2012, and about 60 percent of that decline was due to reduced emissions in eastern China, two teams report online February 10 in Nature.
These findings suggest that the hole in Earth’s ozone layer is still on track to close up within the next 50 years — rather than being delayed, as it would have been if CFC-11 emissions had remained at the levels seen from 2014 to 2017 (SN: 12/14/16).
One group analyzed the concentration of CFC-11, used to make insulating foams for buildings and household appliances, in the air above atmospheric monitoring stations around the globe. The team found that the world emitted about 52,000 metric tons of CFC-11 in 2019 — a major drop from the annual average of 69,000 metric tons from 2014 to 2018. The 2019 emissions were comparable to the average annual emissions from 2008 to 2012, Stephen Montzka, an atmospheric chemist at the U.S. National Oceanic and Atmospheric Administration in Boulder, Colo., and colleagues report.
Back on track
Atmospheric observations from Gosan, South Korea and Hateruma, Japan suggest that annual CFC-11 emissions in eastern China (measured in nanograms per meter squared per second) were higher on average from 2014 to 2017 (center) then they were from 2008 to 2012 (left), but dropped back down to pre-2013 levels in 2019 (right).
Changes inCFC-11 emissions over eastern China, 2008–2019
AGAGE/NASA Earth Observatory
AGAGE/NASA Earth Observatory
The new measurements imply that there has been a significant decrease in illicit CFC-11 production within the last couple of years, the researchers say, probably thanks to more rigorous regulation enforcement in China and elsewhere.
Another group confirmed that emissions from eastern China have diminished since 2018 by analyzing air samples from Hateruma, Japan and Gosan, South Korea. The region emitted about 5,000 metric tons of CFC-11 in 2019, which was about 10,000 metric tons less than its average annual emissions from 2014 to 2017 and was similar to the 2008 to 2012 average. That analysis was led by Sunyoung Park, a geochemist at Kyungpook National University in Daegu, South Korea.
The recent downturn in CFC-11 pollution shows that “the Montreal Protocol is working,” says A.R. “Ravi” Ravishankara, an atmospheric scientist at Colorado State University in Fort Collins not involved in either study. When someone violates the treaty, “atmospheric sleuthing” can uncover the culprits and spur countries to take action, he says. “China clearly took action, because you can see the result of that action in the atmosphere.”
Montzka cautions that it might not always be so easy to point the finger at rogue emitters. “I think we got lucky this time,” he says, because atmospheric monitoring sites in Asia were able to trace the bulk of illegal emissions to eastern China and monitor the situation over several years. Many places around the world, such as in Africa and South America, lack atmospheric monitoring stations — so it’s still a mystery which countries besides China were responsible for the recent rise and fall of CFC-11 emissions.
For most of their lives, plants in the Sapria genus are barely anything — thin ribbons of parasitic cells winding inside vines in Southeast Asian rainforests. They become visible only when they reproduce, bursting from their host as a dinner plate–sized flower that smells like rotting flesh.
Now, new research on the genetic code of this rare plant reveals the lengths to which it has gone to become a specialized parasite. The findings, published January 22 in Current Biology, suggest that at least one species of Sapria has lost nearly half of the genes commonly found in other flowering plants and stolen many others directly from its hosts.
The plant’s rewired genetics echo its bizarre biology. Sapria and its relatives in the family Rafflesiaceae have discarded their stems, roots and any photosynthetic tissue.
“If you’re out in the forest in Borneo and these [plants] aren’t producing flowers, you’re never even going to know they’re there,” says Charles Davis, an evolutionary biologist at Harvard University.
For years, Davis has been studying the evolution of this group of otherworldly parasites, which includes the largest flower in the world, Rafflesia arnoldii (SN: 1/10/07). When some genetic data showed a close relationship between these parasites and their vine hosts, Davis suspected horizontal gene transfer. That’s where genes move directly from one species to another — in this case, from host to parasite. But no one had yet deciphered the genome — the full genetic instruction book — for these plants.
So Davis and his team sequenced many millions of pieces of Sapria himalayana’s genetic code, assembling them into a cohesive picture of that species’ genome. When the team analyzed the genome, they found an abundance of oddities.
About 44 percent of the genes found in most flowering plants were missing in S. himalayana. Yet, at the same time, the genome is about 55,000 genes long, more than that of some other non-parasitic plants. The count is inflated by many repeating segments of DNA, the team found.
Loss of the chlorophyll pigments responsible for photosynthesis is common in parasitic plants that rely on their hosts for sustenance. But S. himalayana appears to have even scrapped all genetic remnants of its chloroplasts, the cellular structures where photosynthesis occurs.
Chloroplasts have their own genome, distinct from the nuclear genome that runs a plant’s cells and the mitochondria that produce energy for the cells. S. himalayana seems to have lost this genome altogether, suggesting that the plant has purged the last remnants of its ancestral life that allowed it to make its own food.
“There is no other case” of an abandoned chloroplast genome among plants, says Davis. Earlier work by other researchers had suggested that the genome may be missing. “Our work clearly verifies that indeed it’s totally gone,” he says, noting that even genes in S. himalayana’s nuclear genome that would regulate components of the chloroplast genome have vanished.
It may be too early to declare the chloroplast genome completely missing in action, cautions Alex Twyford, an evolutionary biologist at the University of Edinburgh who was not involved with this research. It may be difficult to definitively prove the genome is gone, he says, especially if the chloroplast is “unusual in its structure or abundance” and therefore difficult to identify.
Among the remaining parts of the nuclear genome, the team also found that more than 1 percent of S. himalayana’s genome comes from genes stolen from other plants, likely its current and ancestral hosts.
The potential scale of the vanished genome and the volume of repeating bits of DNA are “insane,” says Arjan Banerjee, a biologist at the University of Toronto Mississauga also not involved with this study. The “industrial scale” of the plant’s gene theft is also impressive, he says.
There are still plenty of weird elements left in S. himalayan’s genome to explore, says study coauthor Tim Sackton, an evolutionary biologist also at Harvard. For example, the plant has bloated its genome with extraneous DNA, while most parasites streamline their genomes. “There’s something weird and different going on in this species,” he says, adding that many of the DNA fragments the parasitic plant is stealing from its host don’t appear to encode any genes, and likely don’t do anything important.
The new discovery illustrates the level of commitment S. himalayana and its relatives have given to evolving a parasitic lifestyle, and provide a comparison to other extreme plant parasites (SN: 7/31/20). And for Davis, plants like S. himalayana can help researchers determine some of biology’s limits. These plants have lost half their genes, yet they still survive, he notes. “Maybe these organisms that stretch the boundaries of existence tell us something about how far the rules can be bent before they can be broken.”
Quantum bits made from “designer molecules” are coming into fashion. By carefully tailoring the composition of molecules, researchers are creating chemical systems suited to a variety of quantum tasks.
“The ability to control molecules … makes them just a beautiful and wonderful system to work with,” said Danna Freedman, a chemist at Northwestern University in Evanston, Ill. “Molecules are the best.” Freedman described her research February 8 at the annual meeting of the American Association for the Advancement of Science, held online.
Quantum bits, or qubits, are analogous to the bits found in conventional computers. But rather than existing in a state of either 0 or 1, as standard bits do, qubits can possess both values simultaneously, enabling new types of calculations impossible for conventional computers.
Besides their potential use in quantum computers, molecules can also serve as quantum sensors, devices that can make extremely sensitive measurements, such as sussing out minuscule electromagnetic forces (SN: 3/23/18).
In Freedman and colleagues’ qubits, a single chromium ion, an electrically charged atom, sits at the center of the molecule. The qubit’s value is represented by that chromium ion’s electronic spin, a measure of the angular momentum of its electrons. Additional groups of atoms are attached to the chromium; by swapping out some of the atoms in those groups, the researchers can change the qubit’s properties to alter how it functions.
Recently, Freedman and colleagues crafted molecules to fit one particular need: molecular qubits that respond to light. Lasers can set the values of the qubits and help read out the results of calculations, the researchers reported in the Dec. 11 Science. Another possibility might be to create molecules that are biocompatible, Freedman says, so they can be used for sensing conditions inside living tissue.
Molecules have another special appeal: All of a given type are exactly the same. Many types of qubits are made from bits of metal or other material deposited on a surface, resulting in slight differences between qubits on an atomic level. But using chemical techniques to build up molecules atom by atom means the qubits are identical, making for better-performing devices. “That’s something really powerful about the bottom-up approach that chemistry affords,” said Freedman.
Scientists are already using individual atoms and ions in quantum devices (SN: 6/29/17), but molecules are more complicated to work with, thanks to their multiple constituents. As a result, molecules are a relatively new quantum resource, Caltech physicist Nick Hutzler said at the meeting. “People don’t even really know what you can do with [molecules] yet.… But people are discovering new things every day.”
Guttural toads on islands in the Indian Ocean have shrunken limbs and bodies that may be evidence that “island dwarfism” can evolve quickly, Jake Buehler reported in “Toads on two islands are shrinking fast” (SN: 12/19/20 & 1/2/21, p. 13).
“I thought that island dwarfism usually happens to quite large animals … and that small animals … tend to evolve to larger sizes on islands,” reader Tim Cliffe wrote. “If small animals do tend to grow larger, do the authors talk about why these small toads would instead be taking the dwarfism route?”
Generally speaking, yes, large animals become smaller when they colonize islands, and small animals get bigger, Buehler says. “This ‘island rule’ isn’t absolute, and whether or not an animal moves toward dwarfism or gigantism may depend on the benefits normally afforded to them by their body size, and food constraints on the island,” he says. The researchers noted that a relatively large body size may protect guttural toads against predators. On the islands, the toads may have become smaller since there are fewer hungry predators to dissuade, Buehler says.
Or perhaps the island toads have a spread-out mating schedule, which could explain why the amphibians are shrinking. “On the mainland, guttural toads mate once a year, and females that grow to large sizes very quickly produce a lot of eggs,” Buehler says. But the island toads may be mating year-round, which would deflate the importance of getting large and producing a ton of eggs. “Figuring out exactly why island life is making these toads smaller is the next step in this project,” he says.
Defining distance
A collision of two black holes 17 billion light-years from Earth snagged records for the farthest, most energetic and most massive black hole merger, Erika Engelhaupt wrote in “Superlative science” (SN: 12/19/20 & 1/2/21, p. 34).
Some readers wondered how the black hole merger could have occurred 17 billion light-years from Earth if the Big Bang occurred 13.8 billion years ago.
“Distance is actually quite complicated to define for a universe that is expanding and in which spacetime is not static,” says Science News physics writer Emily Conover. “The gravitational waves produced by the merger took 7 billion years to reach us. That’s what’s called ‘lookback time,’ ” she says. “But that’s not the same thing as the distance of the source from us. Because the universe has expanded in the time it took those waves to reach us, the source is indeed 17 billion light-years away, according to one standard method of defining distance. That’s also why that distance doesn’t conflict with the age of the universe,” she says.
Room to improve
A compound in hallucinogenic mushrooms eased depression symptoms in 13 people in a small study, but larger studies are needed, Laura Sanders reported in “Psilocybin may help treat depression” (SN: 12/19/20 & 1/2/21, p. 6).
“The article spoke of concern that most participants were white and that a broader diversity would be more helpful” to determine how effective the compound is, reader Robert Walty wrote. “This is quite true and as a 75-year-old man, I am also concerned about depression in the elderly,” he wrote, noting that depression is common among older adults. “I look forward to larger studies with a truly broad diversity of participants.”
When the news broke in April 2019 that scientists had restored neurological functions in the brains of dead pigs, I was fascinated — and troubled. Though this groundbreaking work could lead to better treatments for stroke and other brain injuries, it also opened an eerie gray zone between the living and the dead.
Scientists are wrestling with the ethical questions posed by the pig brain experiment and other advances in brain science, as neuroscience writer Laura Sanders pointed out in her coverage of that breakthrough (SN: 5/11/19 & 5/25/19, p. 6). But information on scientific advances typically flows from scientists to journalists and then out to the public — there’s little opportunity for the public to talk with scientists or voice concern about the implications of research before the science happens. Could we help those conversations happen? We decided to run an experiment to find out.
This issue includes the first step in our experiment. Last fall we surveyed Science News readers, asking what they thought about neurotechnology, including brain implants and other devices that already have the ability to listen in and change how our brains work. Of three concerns — autonomy, fairness and privacy — privacy was the biggest worry among respondents. Sanders used that information to focus her reporting for this issue’s cover story. “Asking readers what they thought directly was a great way to get perspective and find out what they’re interested in,” she told me, “which is something we’re trying to do all the time.”
Readers didn’t hold back. “I have no wish/desire to be a zombie or a clone,” one wrote. Others noted how giving scientists (and perhaps corporations and politicians) access to our brains could blur our sense of self. “It was so satisfying and important to get the public’s perspective,” Sanders said. “They’re just left out in so many of these conversations.”
We also asked readers to share their thoughts about genetics and race, including bias in genomic databases used for medical research and issues of genetic privacy. Senior writer Tina Hesman Saey will report on that experiment next month.
And we’re eager to continue this work. Please let us know what you think by writing us at [email protected]. “I really do see this as the starting point; I would love to do more,” Sanders said.
This project was made possible with support from the Kavli Foundation, which gave us the chance to step back from daily news coverage a bit and see if we could help more people become part of the conversations — and, ideally, decisions — about science’s impact on society, our bodies and our minds.
This issue also features the second theme in our Century of Science project. Special projects editor Elizabeth Quill explores the implications of Einstein’s general theory of relativity, which was considered shocking in the early 1900s. Since then, scientists have discovered black holes and other exotic denizens of the universe that wouldn’t have seemed possible before Einstein changed our view of the cosmos.
Vaccine rollout in the United States has been undeniably slow. And while we wait, worrisome new coronavirus variants are emerging, heightening the urgency to control the pandemic. Some variants, including ones first identified in Brazil, South Africa and the United Kingdom, have mutations that help the coronavirus evade parts of the immune system, raising the specter that some people might face a second round of COVID-19.
All of this can make it feel like the pandemic has come full circle and that we are back where we started. But even in the face of potential reinfections, the world has a tool at its disposal that didn’t exist a year ago: effective vaccines.
Shots from Pfizer and Moderna have been authorized in the United States since December 2020. Vaccines developed by Novavax and Johnson & Johnson recently announced promising results (SN: 1/28/21; SN: 1/29/21). On February 4, Johnson & Johnson became the third company to apply for emergency use authorization in the United States for its COVID-19 vaccine.
And preliminary data from AstraZeneca suggest that a single dose of its vaccine may lower the number of people who test positive for the coronavirus virus by 67 percent, possibly reducing the spread of the virus in the community, researchers reported February 1 in Preprints with the Lancet. Curbing transmission is the holy grail of vaccine effectiveness: That would give the coronavirus fewer chances to acquire potentially dangerous mutations (SN: 1/27/21). That, in turn, could finally bring the end of the pandemic into view.
In the meantime, researchers are grappling with understanding the threat the known mutations pose. Even if someone has antibodies to the coronavirus — through a natural infection or a vaccine — some mutations can stymie the antibodies’ ability to latch onto the virus and prevent it from infecting cells. Though antibodies make up only one part of the immune system’s arsenal to eliminate viruses from the body, the variants’ ability to dodge the immune proteins could put people who have already recovered from a bout of COVID-19 at risk of getting infected again.
The first confirmed reinfection with SARS-CoV-2, the virus that causes COVID-19, was reported in August (SN: 8/24/20). There have been some documented cases of reinfection with new variants as well — including in Manaus, Brazil and in an Israeli traveler to South Africa — although some details remain unclear.
Reinfections are difficult to prove. Doctors need genetic evidence to show that a distinct coronavirus strain caused each instance of infection. What’s more, some people might never develop symptoms and remain unaware of a second infection. As a result, researchers still don’t know how often people are reinfected with the coronavirus.
To explore what the emergence of new variants might mean for reinfections, vaccines and the pandemic, Science News spoke to Aubree Gordon, an epidemiologist at the University of Michigan in Ann Arbor. This interview has been edited for brevity and clarity.
SN: What have we learned about reinfection since August?
Gordon: We know [reinfections] happen. We don’t know much beyond that. There are a number of studies out there, and there have been case reports of reinfections, but at this point we still don’t know how common they are. What you would expect to see with reinfections is that as people get further out from having their first infection, you would see more reinfections. But of course, at this point, we’re a little bit over a year into the pandemic so there hasn’t been a lot of time for many people to get reinfected yet.
SN: Why hasn’t there been enough time? Why do reinfections happen?
Gordon: Reinfections occur for a variety of different reasons. But, generally, it’s because somebody no longer has sufficient immunity to the virus to prevent them from getting infected.
If you’ve got the same virus [without mutations], people may get reinfected because they did not mount a really strong response to the virus the first time they were infected. Or maybe they did mount a strong response but then that response wanes or decreases over time, to the level where it isn’t protective against getting infected again.
Another way that reinfections occur is that the virus may change. If there are changes in the virus that occur so that your antibodies no longer recognize the virus or some areas of the virus, at least, then reinfections may occur. In particular for SARS-CoV-2, those [changes] could be to its spike [the protein the virus uses to break into a cell].
The same thing happens with flu on a pretty regular basis. The virus changes. Because the virus changes, our bodies don’t recognize it, and then we can get reinfected with the virus.
SN: What do we know about the role the new variants will play in reinfection?
Gordon: I definitely think the reports of reinfections are concerning. But I think we need to figure out how common these reinfections are versus people who hadn’t previously had [COVID-19] and look at what the risk is.
Are [reinfected] people not protected [from the new variants] at all? I think that’s probably not the case. My guess is that a lot of people who have previously had SARS-CoV-2 are probably still protected in part, or not as protected. They may be more likely [to get infected again with the new variant] than they would with the original virus. But if you compare them to people who have never had COVID-19 before or don’t have antibodies from the vaccine, you would still see a significant amount of protection. But we still don’t have that data.
We also don’t know how severe those reinfections are. Researchers tend to catch the severest cases — the tip of the iceberg — and that doesn’t necessarily give you a full picture of what’s going on. We’ve certainly seen a number of individual case reports with severe reinfections, but most severe cases are going to have the best access to testing [which can overrepresent how often that happens].
SN: If vaccines slow transmission, how does that help?
Gordon: The availability of additional vaccines, such as the AstraZeneca vaccine, will speed up the vaccination process. And if the vaccines do reduce transmission, that is also very good news. [Fewer cases mean fewer opportunities for the virus to mutate.]
Even before the emergence of the variants, it was critical that we vaccinate as many people as quickly as possible and the variants have only amplified that. High levels of transmission of SARS-CoV-2 combined with a large proportion of people with preexisting immunity to the original virus could lead to new variants. It also gives an advantage to existing variants that have changed enough that preexisting immunity is no longer as protective.
SN: What does all of this mean for herd immunity and vaccines?
Gordon: It’s going to be very difficult to achieve herd immunity if you have a very significant rate of reinfection in people without immunity to new variants.
I’ve heard a number of people in my personal life recently express thoughts like, “Oh my gosh, is this pandemic ever going to end? Are we just going to live like this forever?” And that’s unlikely.
What we’ll probably find is that [reinfections] are going to continue to occur as the variants become more prevalent. Reinfections will probably occur more frequently, particularly as people get further out from their original infection.
But I think our top concerns are severe cases and deaths. We might continue to see transmission even if everybody has immunity to the original virus. But the thing that’s important is to ask what do [the symptoms] of cases [of reinfection] look like. I think everybody — including myself — is hopeful that we’re going to see a drastic reduction in severity of cases when you compare reinfections to a first infection.
Certainly, some lab data suggest that perhaps the vaccines are not going to work as well against the variants. But for the Novavax vaccine, even though it was less effective for preventing symptomatic SARS-CoV-2 infection in South Africa, where variant B.1.351 is very prevalent, it was still 100 percent effective against severe disease. I think that that’s something important that people need to pay attention to.
The reason we’ve all changed our lives the way we have and have all the measures [like mask wearing and physical distancing] is because COVID-19 is causing hospitalizations and deaths. It’s causing severe disease, it’s causing severe after-effects, and [preventing those] is what we really care about.
Vaccine companies are already starting to look into potentially making a booster or a second vaccine. We might end up with a bivalent vaccine, for example, that has both the original strain and one of the [viral] variants that’s better at evading the immune system.
SN: So when will the pandemic end?
Gordon: It’s going to be a little bit longer than it would have been without those variants arising. But pandemics always end eventually.
We can look back at flu pandemics — you usually have one or two years of circulation before enough immunity builds up to the virus. People may continue to get infected with the virus, but the infections are not as severe. And you don’t have as many people getting infected in any given year because of pre-existing immunity.
I think the [pandemic] timeline with the introduction of variants may be a little bit longer. But eventually, I think we’re going to arrive at a place where SARS-CoV-2 is endemic, [a commonly circulating] human coronavirus. Depending on the severity of reinfections and the length of immunity that’s generated by vaccines, we may or may not need additional booster vaccines for SARS-CoV-2 going forward.
The paucity of Lyme disease cases in the southern United States may be partly due to what black-legged ticks in southern locales bite.
Although black-legged ticks (Ixodes scapularis) claim much of the eastern half of the country as their home, the Lyme disease they spread is largely concentrated in the Northeast and increasingly in the upper Midwest.
It’s well known that ticks in the Northeast commonly latch on to white-footed mice. This relationship turns out to be a boon for Lyme disease. When infected with the bacteria Borrelia burgdorferi, which causes Lyme disease, these mice very efficiently spread it to the ticks, which can then pass it on to people.
But southern-residing ticks are different. They are more likely to bite lizards called skinks, which are poor transmitters of the bacteria, researchers report January 28 in PLOS Biology.
This study “shows that there’s this really interesting switch” north to south in the predominant tick host, says disease ecologist Shannon LaDeau of the Cary Institute of Ecosystem Studies in Millbrook, N.Y., who was not part of the research team. “It looks like that is reducing the transmission” in the South of the bacteria that causes Lyme disease.
An estimated 476,000 people are diagnosed with Lyme disease each year in the United States, according to insurance data from 2010 to 2018. In about 70 to 80 percent of cases, a rash in the area of the tick bite is an early sign of the disease; other symptoms include fever, fatigue and achiness. Most people recover with early antibiotic treatment. If the diagnosis is missed, the infection can spread in the body and cause arthritis and nerve pain (SN: 6/22/19).
Scanning for and removing ticks after a hike is one part of Lyme disease control. Understanding the ticks’ behavior and their relationship to the environment can inform other prevention methods.
Black-legged ticks need blood meals to progress through several developmental stages. The larvae that emerge from eggs are the first to seek out a host for blood; this is the point when they can first become infected with Lyme bacteria. The next blood meal is at the nymph stage. Nymphs infected as larvae can spread the bacteria to other hosts, including people.
There’s been a long debate about the difference in Lyme disease cases between the North and the South, says research ecologist Howard Ginsberg at the Patuxent Coastal Field Station at the University of Rhode Island in Kingston. The ticks are in the South, so “why isn’t there much Lyme disease?”
One possible reason is that nymphal ticks in the North seek hosts on top of or above leaf litter, which puts them in the path of passing hikers. But nymphal ticks in the South are more likely to stay under leaf litter, reducing the chance of such encounters, researchers reported in Ticks and Tick-borne Diseases in 2019. It may be that the ticks remain below the leaf litter in the hotter South to avoid drying out.
This host-seeking behavior and the results of the new study help to explain the North-South difference, Ginsberg says. In 2011 and 2012, he and his colleagues captured host animals in live traps and collected and tested ticks at eight sites in the eastern half of the United States. “We tried to catch everything that crawled on the ground that the tick might attach to,” he says.
In the North, the most common hosts were mice, while in the South, the ticks selectively attached to skinks, Ginsberg says. At the Massachusetts site, for example, 75 percent of the larvae and 93 percent of the nymphs were removed from mice, which accounted for 79 percent of the captured host animals. The team caught no skinks.
But at the Florida site, although around 40 percent of the animals captured were mice, they had only 3 percent of the larvae and less than 1 percent of the nymphs. Meanwhile, skinks — which made up 28 percent of the host animals captured — had 92 percent of the larvae and 98 percent of the nymphs. The team also found that the ticks at the northern sites were much more likely to be infected with Lyme bacteria than ticks from southern sites.
Understanding the ecological context of Lyme disease can help identify targets to try to reduce human risk, LaDeau says. For example, the possibility of vaccinating mice against Lyme bacteria (SN: 8/9/17) may be more useful in the North.
The differences seen north to south also influence predictions of how climate change could impact Lyme disease. Black-legged ticks have moved farther north, bringing Lyme disease to Canada, in part due to warming. Perhaps the behaviors and biting patterns in the South will eventually expand to Maryland, Delaware and Virginia, reducing Lyme disease cases there, says Ginsberg. It will take more research to learn how climate change will affect skink populations and how warming might change tick behavior, he says.
In the late 1800s, Santiago Ramón y Cajal, a Spanish brain scientist, spent long hours in his attic drawing elaborate cells. His careful, solitary work helped reveal individual cells of the brain that together create wider networks. For those insights, Cajal received a Nobel Prize for physiology or medicine in 1906.
Now, a group of embroiderers has traced those iconic cell images with thread, paying tribute to the pioneering drawings that helped us see the brain clearly.
The Cajal Embroidery Project was launched in March of 2020 by scientists at the University of Edinburgh. Over a hundred volunteers — scientists, artists and embroiderers — sewed panels that will ultimately be stitched into a tapestry, a project described in the December Lancet Neurology.
Catherine Abbott, a neuroscientist at the University of Edinburgh, had the idea while talking with her colleague Jane Haley, who was planning an exhibit of Cajal’s drawings. These meticulous drawings re-created nerve cells, or neurons, and other types of brain cells, including support cells called astrocytes. “I said, off the cuff, ‘Wouldn’t it be lovely to embroider some of them?’”
The project had just begun when the COVID-19 pandemic upended the world. But stitching at home amid the shutdowns was a soothing activity, says Katie Askew, a neuroimmunologist at the University of Edinburgh. “Having something that can occupy your hands so you’re not scrolling through your phone looking at the news is great,” she says. Askew chose to re-create a type of neuron known as a Purkinje cell from a human cerebellum, a structure at the back and bottom of the brain that helps coordinate movement. Purkinje cells collect signals with lush thickets of tendrils, before sending along their own quieting signals. Cajal’s particular specimen nearly filled Askew’s fabric panel. “They are amazing cells,” she says. Spending months staring at a single cell has led her to spot similar branches in trees, she says.
To honor the insights of Santiago Ramón y Cajal, embroiderers re-created nine of his iconic drawings, which spanned an array of cell types in the brain.Cajal Embroidery Project; top row (left to right): Liz Ribchester, Katie Askew, Janet Philp; middle row: Carol Coleman, Jane Haley, Emma Perkins; bottom row: Niki Stypidou, Melanie Stefan, Alison Todd
Cajal’s artistic eye is obvious in his drawings, says Annie Campbell, one of the volunteers who contributed a square. “His images live in this liminal space between science and fine art,” says Campbell, who is herself an artist at Auburn University in Alabama. “He was making aesthetic decisions about what to leave out so that somebody could look at that and say, ‘Oh, that’s a neuron without all its dendrites so I can see the astrocyte wrapped around it.’”
Campbell decided to embroider an astrocyte with looping tendrils “for the beauty of the shape,” she says. As she sewed, she also began to learn more about the cells, which perform a variety of crucial jobs in the brain, including healing injuries.
Cajal’s drawings are still relevant today, says Abbott. “What strikes me the most is how completely timeless they are.” Even with powerful, high-resolution microscopes, scientists today see cells in a similar way. “It’s almost depressing to think that even with all of this fancy equipment, we’re not all that far ahead,” she says. “But I like that. I like that there is this direct connection to 100 years ago.”
That thread ties the embroiderers today to Cajal’s work, Abbott says. “We are looking at the same thing and feeling the same sense of wonder.”
