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Scientific American
a day ago
- Science
- Scientific American
Velvet Worm Slime Reveals Its Sticky Secrets
The velvet worm, a squishy little predator that looks like the stretch-limo version of a caterpillar, has a whimsical MO: it administers death by Silly String. In the leaf litter of tropical and temperate forests around the world, velvet worms stalk the night on dozens of stubby legs. The pocket-size predator—whose species range from less than half an inch to eight inches long—can barely see, so it bumbles around, hoping to literally bump into an edible bug such as a cricket or a woodlouse. When it finds one, the velvet worm uses nozzles on either side of its face to shoot jets of sticky slime at its victim. 'It happens so fast it's almost like they're sneezing,' says Matthew Harrington, a biochemist at McGill University who has studied velvet worms for a decade. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. At first, the goo is a watery liquid, but in midair it transforms into jellylike ropes that ensnare the unlucky creature and stick it to the ground. As the prey struggles, the slime forms fibrous threads, and within seconds the substance hardens into a glasslike solid. Scientists have been intrigued by velvet worm slime's adhesive properties for more than a century. (In the 1870s researchers puzzling over what makes it stick tried tasting it. The verdict: bitter.) Recent findings suggest the phase-shifting goo could inspire a new generation of recyclable bioplastics, according to research published by Harrington and his colleagues in the Proceedings of the National Academy of Sciences USA. Previously, the researchers discovered that soaking the hardened fibers in water returned them to their liquid state—and by rubbing the resultant mess between their fingertips, they could get fibers as strong as nylon to re-form. That means 'everything we need to know about making these fibers is encoded in the proteins themselves,' Harrington says. But isolating those proteins is easier said than done, the scientists found. The slime is so sensitive to touch that even standard laboratory techniques such as pipetting can trigger its phase shift. To avoid that sticky situation altogether, the scientists sequenced the RNA of proteins from the slime of velvet worms collected in Barbados, Singapore and Australia. Then they fed the RNA sequences into AlphaFold3, a program that uses artificial intelligence to predict protein shapes. For all three species, it 'spit out this horseshoe shape' rich in the amino acid leucine, Harrington says. Although this structure is novel to materials scientists, it's old hat to evolution. A similar protein called a toll-like receptor is part of an ancient immune system feature found across plants, invertebrates and vertebrates. These receptors sit on the surface of immune cells, binding tightly to pieces of invading microbes and releasing them later. Harrington and his team suggest the horseshoe-shaped protein may use a similar 'host-guest' dynamic to grab onto other proteins in the slime, binding strongly but reversibly to form the powerful fibers. Those are magic words to materials scientists working on developing replacements for plastic that can be broken down easily and re-formed into new shapes. These horseshoe proteins are a significant find, says Yendry Corrales Ureña, a researcher at Costa Rica's National Laboratory of Nanotechnology who studies velvet worm slime but wasn't involved in the study. She adds, however, that these proteins don't account for important properties of the slime such as its toughness or elasticity. 'They are just one piece of the larger puzzle.' Julian Monge Najera, an ecologist at the University of Costa Rica who researches invertebrate evolution, says the fact that three velvet worm species from different continents have the same protein shape in their slime underscores how incredibly ancient velvet worms are and how long ago their chemical R&D must have occurred. The fossil record shows that velvet worms have existed almost exactly as they do now for at least 300 million years, predating both dinosaurs and today's continents. 'If I could go back in a time machine, the velvet worms I would catch in the post-Cambrian period would be identical to the ones in Costa Rica's cloud forests today,' Monge Najera says—phase-shifting slime and all. Harrington and his team are working to purify the horseshoe protein from the slime and confirm its structure via electron microscopy. 'We won't be milking velvet worms for slime to replace plastics,' Harrington says. 'But we hope to copy their chemical tricks.'
Yahoo
28-05-2025
- General
- Yahoo
Cincinnati beware — cicadas pee. And they have 'stronger streams than many mammals'
Millions if not billions of 17-year cicadas have descended on Greater Cincinnati and Southwest Ohio, creating a deafening noise and leaving behind a real mess in their wake. But that mess is not just the nymph shells they leave behind when they emerge from underground. No, cicadas pee, and unlike most insects, they pee a lot. "[C]icadas are able to pee well above their weight class and produce stronger streams than many mammals," writes Scientific American, reporting on a March 2024 paper published in the journal Proceedings of the National Academy of Sciences USA. Now people bothered by the insects have another reason to be disgusted by them. Here's what to know. According to Scientific American, cicadas feed on the fluid in a plant's xylem system. Because that fluid is 95% water, cicadas must consume 300 times their body weight each day to get enough nutrients. And that means they pee a lot. While most insects flick away liquid waste one drop at a time, cicadas pee "in high-speed streams reminiscent of the bathroom habits of mammals," according to the publication. In fact, cicadas can produce stronger streams than some species of small mammals, per Scientific American, including bats and a breed of rodent known as the Wistar rat. Yes. After 17 years underground, Brood XIV is emerging, and it will bring millions if not billions of the noisy insects to Southwest Ohio and a dozen other states this spring. Brood XIV is one of 15 recognized broods of periodical cicadas that emerge every 13 or 17 years, and one of four that appear in the Buckeye State, according to the Ohio Department of Natural Resources. They emerge when the soil temperature reaches 64 degrees, which typically happens in the second half of May. Annual cicadas emerge worldwide each year, but periodical cicadas are found only in eastern North America. They live underground as nymphs for either 13 or 17 years before emerging above ground in massive numbers. Different populations of periodical cicadas are called 'broods' and are numbered with Roman numerals. They are active for three to four weeks as they focus on mating and reproduction, per ODNR. Male periodical cicadas produce a deafening chorus of calls to attract females. Once mated, female cicadas deposit their eggs into the branches of trees and shrubs. Brood XIV cicadas will stretch from northern Georgia to Massachusetts. In Ohio, they will emerge in more than a dozen counties, per ODNR, mostly in Southwest Ohio: Adams Brown Butler Champaign Clermont Clinton Gallia Greene Hamilton Highland Jackson Lawrence Pike Ross Scioto Warren Washington Some of the edge counties will not see as heavy an emergence as others. The cicadas that emerge every 13 or 17 years are different from the ones seen every summer, and it's not just the amount of time between sightings. Dr. Gene Kritsky with Mount St. Joseph University in Cincinnati and founder of Cicada Safari, a group that tracks the emergence of cicadas based on user submissions, told WKRN in Nashville that periodical cicadas emerge in May or June, while annual cicadas show up later, in late June and July, and through the rest of summer. While swarms of noisy insects may be unsettling for some, cicadas are harmless to people and pets, according to ODNR. They are also a valuable food source for native wildlife, including birds, mammals and fish. Egg-laying by female cicadas can cause 'flagging' on trees and shrubs (death of branch tips, from the egg-laying site to the end of the branch), but there is little to no impact on established, otherwise healthy plants, ODNR states. Small or newly planted trees and shrubs are more vulnerable to damage and can be protected by covering them with fine netting for the few weeks that adult cicadas are active. Using pesticides on cicadas is not warranted or recommended. States expecting cicadas this year include Georgia, Kentucky, Maryland, Massachusetts, New Jersey, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia and West Virginia, Gene Kritsky, founder of Cicada Safari, a group that crowdsources and reviews data on cicadas, told USA TODAY. Kentucky and Tennessee probably will get the most cicadas this year, said John Cooley, an ecology and biology associate professor in residence at the University of Connecticut. There will also be large numbers in Georgia, the Carolinas and Pennsylvania, he said. This article originally appeared on Cincinnati Enquirer: Do cicadas pee? Way more than most insects. What to know about Ohio brood
Scientific American
12-05-2025
- Science
- Scientific American
Convergent ‘Cuteness' Is Making Dogs and Cats Look Alike
What do Persian cats, Pekingese dogs and pugs have in common? They all share a dramatically distorted skull, with a flat, round face and a nose pushed up between their eyes. This unnatural morphology is the product of decades or centuries of artificial selection to make our pedigreed animals more closely resemble the intrinsic cuteness of human babies. These breeds have become so morphologically extreme, in fact, that the cats and dogs with these features now have skulls that are more similar to each other than to their own wild ancestors, according to new research in the Proceedings of the National Academy of Sciences USA. 'Wolves and wild cats are quite distinct in skull shape, but by applying [selective breeding] pressure for babylike faces, we've caused short-faced dogs and cats to become very similar to each other,' says senior author Jonathan Losos, an evolutionary biologist at Washington University in St. Louis. 'We've substantially erased 50 million years of evolution.' On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Dogs and cats with round, flat faces—technically called brachycephalic, from the Greek for 'short head'—show an unusual example of convergent evolution, which occurs when species independently evolve to become similar to each other because they face the same selective pressures. Normally this process is driven by natural selection—for example, birds and bats have both evolved to fly, and distantly related marine animals keep evolving to look like crabs. But in the case of brachycephalic cats and dogs, it's caused by selective breeding to accommodate human preferences for babylike features, such as round, flat faces with high noses. 'These are completely new skull shapes that only came about because of what humans want to see in their companion animals,' says lead author Abby Grace Drake, an evolutionary biologist at Cornell University. Human preferences, however, come with consequences for the brachycephalic animals involved —which could not survive in the wild. 'We're breeding them to look cute, but this has led to very horrible health problems for them,' Drake says. Pets like Persians and pugs often have so much difficulty breathing that they often require corrective surgery, for example, and they frequently suffer from problems with their eyes, teeth and neurological systems. They are also intolerant to heat and exercise because they lack adequate oxygen. Drake, Losos and their co-authors had originally set out to understand the diversity of skull shapes in cats and dogs. They collected skull measurements for 1,810 animals from various sources, including computerized tomography (CT) scans of pets from animal hospitals and specimens from natural history museums. Their sample included 148 domestic cats and 677 domestic dogs, including both purebreds and mixed breeds. Of the dogs, they classified eight breeds as extremely brachycephalic: Boston terrier, Brussels griffon, English bulldog, French bulldog, Japanese chin, Pekingese, pug and shih tzu. For the cats, Persians, Himalayans and Burmese fell into that category. The team also collected data from hundreds of skulls of dozens of wild species representing the majority of the Canidae and Felidae families, to which domestic dogs and cats belong, respectively. To directly compare the animals, the team created three-dimensional models of each skull and marked anatomically similar points on them across species and breeds. The researchers found that skull shapes of brachycephalic animals are unlike anything that has evolved in nature; these breeds—whether cats or dogs—shared more similarities to each other in skull structure than they did to their wild ancestors. Specifically, their palate has been tilted up, which has drastically shrunk their nasal region and restricted their airway as well as the space at the back of their throat. Some Persian cats actually lacked nasal bones entirely. 'People talk about evolution taking millions of years,' Drake says. 'But if you isolate the gene pool with inbreeding and force massive selection pressures, you can produce a remarkable amount of diversity in a short period of time.' While this is fascinating from an evolutionary biology point of view, she and her colleagues emphasize that they do not think it is worth the health consequences for the animals. Losos agrees: 'The welfare of the animals should be the first priority,' he says. One future question for researchers to investigate is the underlying genetics of brachycephalic features, he adds. Some evidence suggests that domestic dogs and cats each have different genes associated with brachycephaly. 'Finding out more about the genetics would certainly be fascinating,' Losos says. Heather Lorimer, a geneticist at Youngstown State University, who was not involved in the research, agrees it would be worthwhile for scientists to investigate the genetics behind brachycephalic features. 'Starting from a careful, descriptive paper like this one, it might be possible to home in on individual developmental control genes that affect specific skull structure elements,' Lorimer says. 'This, in turn, could lead to understanding very specific changes that cause health issues, which could help in breeding choices to improve health and welfare of our pedigreed dogs and cats.' For those looking for a healthy pet that does not contribute to welfare issues, though, Drake has simple advice: get a mixed-breed animal from a shelter.
Scientific American
12-05-2025
- Science
- Scientific American
Knitting's Complex Shapes Explained in New Physics Model
In the core of a knitting machine or at the tips of a skilled knitter's needles, a strand of fiber can be transformed into anything from a delicate scarf to a bulletproof vest. But different knitting stitches tend to twist in different directions—think of a T-shirt curling at the bottom edge if the hem is cut off. The tension these stitches create can warp a two-dimensional fabric into complex 3D shapes, and predicting the final structure of a knitted project challenges crafters and manufacturers alike. Now a mathematical model published in the Proceedings of the National Academy of Sciences USA uses physics to untangle this issue. Physicists are always searching for rules that govern materials' behavior, explains study lead author Lauren Niu, a physicist at Drexel University. Once rules are established, Niu says, 'that's where the magic happens.' Prediction becomes possible. Niu worked with University of Pennsylvania physicist Randall D. Kamien and Geneviève Dion, founding director of Drexel University's Center for Functional Fabrics, to find a mathematical model that reliably forecasts a knitted textile's complicated shapes and folds based on the stitch pattern used. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. The researchers started by knitting complex patterns—including squiggles, peaks, and fabric that folded into the shape of a face—and then reverse engineered the knitted items' geometries. They realized they did not have to account for each stitch's actual shape and stretch, which would require too much computational power at the necessary scale, to foretell a textile's final form. Instead they needed to know only how each kind of stitch tended to curve the fabric. The new model incorporates information about how stitches produce tension into an intricate mathematical construction called a Föppl–von Kármán equation. These equations describe how thin, flexible materials—such as cellular tissues and submarine hulls—behave under internal and external forces. Mapping knit stitches this way makes it possible to experiment with textile designs before physically knitting the material, Kamien says. He hopes such virtual testing will lead to more advanced, customized textiles for objects such as wearable medical devices. 'Having something that is as incredibly tunable and scalable and cheap as knitting for wearable devices is, I think, very exciting,' says Stanford University mechanical engineer Cosima du Pasquier, who was not involved in the new study. Du Pasquier, who studies soft robotics that use functional textiles, would like to see how the model's predictions quantitatively line up with real-world fabrics and whether varying factors such as fabric thickness and yarn type affect that comparison. Even without refinement, the study authors say, the model offers a practical starting point for trying new designs. 'You can't capitalize on [knitting's] potential if you're still based on trial and error,' Dion says. 'We're starting to be able to experiment in the virtual environment.'
Scientific American
09-05-2025
- Science
- Scientific American
Linguists Find Proof of Sweeping Language Pattern Once Deemed a ‘Hoax'
In 1884 the anthropologist Franz Boas returned from Baffin Island with a discovery that would kick off decades of linguistic wrangling: by his count, the local Inuit language had four words for snow, suggesting a link between language and physical environment. A great game of telephone inflated the number until, in 1984, the New York Times published an editorial claiming the Inuit have '100 synonyms' for the frozen white stuff we lump under a single term. Boas's observation had swelled to mythic proportions. In a 1991 essay, British linguist Geoff Pullum called these claims a 'hoax,' citing the work of linguist Laura Martin, who tracked the misinformation's evolution. He likened it to the xenomorph from Alien, a creature that 'seemed to spring up everywhere once it got loose on the spaceship, and was very difficult to kill.' His acerbic critique rendered the subject taboo for a generation, says Victor Mair, an expert on Chinese language at the University of Pennsylvania. But now, he says, 'it's coming back in a legitimate way.' In a sweeping new computational analysis of world languages, researchers not only confirmed the emphasis on snow in the Inuit language Inuktitut but also uncovered many similar patterns: what snow is to the Inuit, lava is to Samoans and oatmeal to Scots. The results were published in the Proceedings of the National Academy of Sciences USA in April. Charles Kemp, a computational psychologist at the University of Melbourne in Australia and senior author of the study, says the results offer a window onto language speakers' culture. 'It's a way to get a sense of the 'chief interests of a people'—what's important to a society, what they prioritize and value,' he says, quoting Boas. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. The researchers analyzed bilingual dictionaries between English and more than 600 languages, looking for what they call 'lexical elaboration,' in which a language has many words related to a core concept. It's the same phenomenon that fueled the Inuit debate. But this study brings a twist: rather than the number of words, it measured their proportion, the slice of dictionary real estate taken up by a concept. This produced elaboration scores for hundreds of concepts, from 'abandonment' to 'zoo,' based on how many times the English words for those concepts appeared in the definitions of foreign words. You can explore the results in this online module that shows which languages have the most words for each concept and which concepts have the most words in each language. Often the elaboration is clearly a product of environment—small wonder that Arabic, Farsi and Indigenous Australian languages abound with words to describe the desert, and Sanskrit, Tamil and Thai with words for elephants. Other cases aren't so straightforward. Many Oceanic languages, for example, have highly specific words for smell. In Marshallese, meļļā means 'smell of blood' and jatbo means 'smell of damp clothing.' This may be explained by the humidity of the rainforest, which amplifies scents. But why is the concept of rapture so prominent in Portuguese and agony in Hindi? What historical and cultural circumstances lead a language down such obscure paths? 'I'm not sure if anybody knows,' Kemp says. Mair says this research, which he highlighted on the popular linguistics blog Language Log, helps resurrect the much-maligned idea of linguistic relativity, sometimes known as the Sapir-Whorf hypothesis. At its boldest, linguistic relativity asserts that language determines how we perceive things, causing speakers of different languages to experience the world in radically different ways (think of the movie Arrival, in which a character becomes clairvoyant after learning an alien language). But in Mair's opinion, this study supports a softer claim: our brains all share the same basic machinery for perceiving the world, which language can subtly affect but not restrict. 'It doesn't determine,' he says. 'It influences.' Similarly, Lynne Murphy, a linguist at the University of Sussex in England, who was not involved in this study, notes that 'any language should be able to talk about anything.' We may not have the Marshallese word jatbo, but four words of English do the trick—'smell of damp clothing.' It's not that having many precise words for smell reveals mind-blowing cognitive abilities for processing smell; it's simply that single words are more efficient than phrases, so they tend to represent common subjects of discussion, highlighting areas of cultural significance. If we routinely needed to talk about the smell of damp clothing, we'd whittle that unwieldy phrase down to something like jatbo. Still, 'lexical elaboration alone cannot tell us about the culture of its speakers,' at least not with certainty, says study lead author Temuulen Khishigsuren, a Ph.D. candidate at the University of Melbourne. And because this analysis was based on dictionaries, it comes with the biases and limitations of the lexicographers that wrote them. As Murphy puts it, they 'offer only snapshots of a language at a particular time, from a particular angle.' Some of the dictionaries used are decades or centuries old, and they may reflect the archaic concerns of colonizers—to translate the Bible or establish a trade route—as much as those of modern-day speakers. Dictionaries of vast written languages like German or Sanskrit are much larger than those for languages that are exclusively spoken and are loaded with esoteric terminology. Because dictionaries don't represent how people use language in the real world, the next step would be to measure how often people actually talk or write about the concepts being studied, such as snow and smells and elephants. This is difficult for languages without large bodies of written text but could be possible for many languages, especially those used heavily on social media. It bears remembering that these lexical elaborations come from comparison between languages—French only has 'many' words for futility because other languages have fewer. And because all the bilingual dictionaries in this study map back to English—it's the language into which everything else gets translated—the analysis is influenced by the words used in English itself. If we find the patterns of elaboration in other languages unusual, it's safe to assume their speakers will return the favor. 'English is as 'different' as any other language,' Murphy says, which raises the question: 'If we had started from, say, Spanish or Chinese or Malayalam, which concepts would have stood out for English?'
