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On this episode of the Big Brains podcast, a scholar explains the neuroscience of how listening to and playing music builds our mind.
Music plays an important role in all of our lives. But listening to music or playing an instrument is more than just a creative outlet or hobby—it’s also scientifically good for us. Research shows that music can stimulate new connections in our brains; keeping our cognitive abilities sharp and our memories alive.
In a new book, Every Brain Needs Music: The Neuroscience of Making and Listening to Music (Columbia University Press, 2023), Larry Sherman explores why we all need music for our mental well-being—and how it can even help us later in life.
Sherman is a professor of neuroscience at Oregon Health & Science University.
Listen to the episode below:
Read the transcript to the episode. Subscribe to Big Brains on Apple Podcasts, Stitcher, and Spotify.
Source: University of Chicago
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New research digs into how much alcohol hummingbirds consume.
Your backyard hummingbird feeder filled with sugar water is a natural experiment in fermentation—yeast settle in and turn some of the sugar into alcohol.
The same is true of nectar-filled flowers, which are an ideal gathering place for yeast—a type of fungus—and for bacteria that metabolize sugar and produce ethanol.
To biologist Robert Dudley, this raises a host of questions. How much alcohol do hummingbirds consume in their daily quest for sustenance? Are they attracted to alcohol or repelled by it? Since alcohol is a natural byproduct of the sugary fruit and floral nectar that plants produce, is ethanol an inevitable part of the diet of hummingbirds and many other animals?
“Hummingbirds are eating 80% of their body mass a day in nectar,” says Dudley, professor of integrative biology at University of California, Berkeley. “Most of it is water and the remainder sugar. But even if there are very low concentrations of ethanol, that volumetric consumption would yield a high dosage of ethanol, if it were out there. Maybe, with feeders, we’re not only [feeding] hummingbirds, we’re providing a seat at the bar every time they come in.”
During the worst of the COVID-19 pandemic, when it became difficult to test these questions in the wilds of Central America and Africa, where there are nectar-feeding sunbirds, he tasked several undergraduate students with experimenting on the hummers visiting the feeder outside his office window to find out whether alcohol in sugar water was a turn-off or a turn-on. All three of the test subjects were male Anna’s hummingbirds (Calypte anna), year-round residents of the Bay Area.
The results of that study, which appears in the journal Royal Society Open Science, demonstrate that hummingbirds happily sip from sugar water with up to 1% alcohol by volume, finding it just as attractive as plain sugar water.
They appear to be only moderate tipplers, however, because they sip only half as much as normal when the sugar water contains 2% alcohol.
“They’re consuming the same total amount of ethanol, they’re just reducing the volume of the ingested 2% solution. So that was really interesting,” Dudley says. “That was a kind of a threshold effect and suggested to us that whatever’s out there in the real world, it’s probably not exceeding 1.5%.”
When he and his colleagues tested the alcohol level in sugar water that had sat in the feeder for two weeks, they found a much lower concentration: about 0.05% by volume.
“Now, 0.05% just doesn’t sound like much, and it’s not. But again, if you’re eating 80% of your body weight a day, at .05% of ethanol you’re getting a substantial load of ethanol relative to your body mass,” he says. “So it’s all consistent with the idea that there’s a natural, chronic exposure to physiologically significant levels of ethanol derived from this nutritional source.”
“They burn the alcohol and metabolize it so quickly. Likewise with the sugars. So they’re probably not seeing any real effect. They’re not getting drunk,” he adds.
The research is part of a long-term project by Dudley and his colleagues—herpetologist Jim McGuire and bird expert Rauri Bowie, both professors of integrative biology and curators at UC Berkeley’s Museum of Vertebrate Zoology. They seek to understand the role that alcohol plays in animal diets, particularly in the tropics, where fruits and sugary nectar easily ferment, and alcohol cannot help but be consumed by fruit-eating or nectar-sipping animals.
“Does alcohol have any behavioral effect? Does it stimulate feeding at low levels? Does it motivate more frequent attendance of a flower if they get not just sugar, but also ethanol? I don’t have the answers to these questions. But that’s experimentally tractable,” he says.
Part of this project, funded by the National Science Foundation, involves testing the alcohol content of fruits in Africa and nectar in flowers in the UC Botanical Garden. No systematic studies of the alcohol content of fruits and nectars, or of alcohol consumption by nectar-sipping birds, insects, or mammals, or by fruit-eating animals—including primates—have been done.
But several isolated studies are suggestive. A 2008 study found that the nectar in palm flowers consumed by pen-tailed tree shrews, which are small, ratlike animals in West Malaysia, had levels of alcohol as high as 3.8% by volume. Another study, published in 2015, found a relatively high alcohol concentration—up to 3.8%—in the nectar eaten by the slow loris, a type of primate, and that both slow lorises and aye-ayes, another primate, preferred nectar with higher alcohol content.
The new study shows that birds are also likely consuming alcohol produced by natural fermentation.
“This is the first demonstration of ethanol consumption by birds, quote, in the wild. I’ll use that phrase cautiously because it’s a lab experiment and feeder measurement,” Dudley says. “But the linkage with the natural flowers is obvious. This just demonstrates that nectar-feeding birds, not just nectar-feeding mammals, not just fruit-eating animals, are all potentially exposed to ethanol as a natural part of their diet.”
The next step, he says, is to measure how much ethanol is naturally found in flowers and determine how frequently it’s being consumed by birds. He plans to extend his study to include Old World sunbirds and honey eaters in Australia, both of which occupy the nectar-sipping niche that hummingbirds have in America.
Dudley has been obsessed with alcohol use and misuse for years, and in his book, The Drunken Monkey: Why We Drink and Abuse Alcohol (University of California Press, 2014), presented evidence that humans’ attraction to alcohol is an evolutionary adaptation to improve survival among primates. Only with the coming of industrial alcohol production has our attraction turned, in many cases, into alcohol abuse.
“Why do humans drink alcohol at all, as opposed to vinegar or any of the other 10 million organic compounds out there? And why do most humans actually metabolize it, burn it, and use it pretty effectively, often in conjunction with food, but then some humans also consume to excess?” he asks.
“I think, to get a better understanding of human attraction to alcohol, we really have to have better animal model systems, but also a realization that the natural availability of ethanol is actually substantial, not just for primates that are feeding on fruit and nectar, but also for a whole bunch of other birds and mammals and insects that are also feeding on flowers and fruits,” he says. “The comparative biology of ethanol consumption may yield insight into modern day patterns of consumption and abuse by humans.”
This work received support from the National Science Foundation and UC Berkeley’s Undergraduate Research Apprentice Program.
Source: UC Berkeley
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Eukaryotes, complex life forms with nuclei in their cells, including all the world’s plants, animals, insects, and fungi, trace their roots to a common Asgard archaean ancestor, research finds.
That means eukaryotes are, in the parlance of evolutionary biologists, a “well-nested clade” within Asgard archaea, similar to how birds are one of several groups within a larger group called dinosaurs, sharing a common ancestor. The team has found that all eukaryotes share a common ancestor among the Asgards.
No fossils of eukaryotes have been found from farther back than about 2 billion years ago, suggesting that before that, only various types of microbes existed.
“So, what events led microbes to evolve into eukaryotes?” says Brett Baker, associate professor of integrative biology and marine science at the University of Texas at Austin. “That’s a big question. Having this common ancestor is a big step in understanding that.”
Led by Thijs Ettema of Wageningen University in the Netherlands, the research team identified the closest microbial relative to all complex life forms on the tree of life as a newly described order called the Hodarchaeales (or Hods for short). The Hods, found in marine sediments, are one of several subgroups within the larger group of Asgard archaea. The findings appear in Nature.
The Asgard archaea evolved more than 2 billion years ago, and their descendants are still living. Some have been discovered in deep sea sediments and hot springs around the world, but so far only two strains have been successfully grown in the lab. To identify them, scientists collect their genetic material from the environment and then piece together their genomes. Based on genetic similarities with other organisms that can be grown in the lab and studied, the scientists can infer metabolism and other features of the Asgards.
“Imagine a time machine, not to explore the realms of dinosaurs or ancient civilizations, but to journey deep into the potential metabolic reactions that could have sparked the dawn of complex life,” says Valerie De Anda, a researcher in Baker’s lab. “Instead of fossils or ancient artifacts, we look at the genetic blueprints of modern microbes to reconstruct their past.”
The researchers expanded the known Asgard genomic diversity, adding more than 50 undescribed Asgard genomes as input for their modeling. Their analysis indicates that the ancestor of all modern Asgards appears to have been living in hot environments, consuming CO2 and chemicals to live. Meanwhile, Hods, which are more closely related to eukaryotes, are metabolically more similar to us, eating carbon and living in cooler environments.
“This is really exciting because we are looking for the first time at the molecular blueprints of the ancestor that gave rise to the first eukaryotic cells,” De Anda says.
Support for this research came from the Origin of Eukaryotes program at the Moore and Simons Foundations; the US National Science Foundation; the Wellcome Trust Foundation; the European Research Council; the Swedish Research Council; the Dutch Research Council; the National Natural Science Foundation of China; the Wenner-Gren Foundation; the Science for Life Laboratory (Sweden); and the European Commission’s Marie Skłodowska-Curie Actions.
Source: UT Austin
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Monarch butterflies with more white spots are more successful at reaching their long-distance wintering destination, a new study suggests.
Although it’s not yet clear how the spots aid the species’ migration, it’s possible that the spots change airflow patterns around their wings.
“We undertook this project to learn how such a small animal can make such a successful long-distance flight,” says Andy Davis, an assistant researcher in the Odum School of Ecology at the University of Georgia and lead author of the study published in PLOS ONE.
“We actually went into this thinking that monarchs with more dark wings would be more successful at migrating because dark surfaces can improve flight efficiency. But we found the opposite.”
The monarchs with less black on their wings and more white spots were the ones that made it to their ultimate destination, nearly 3,000 miles away in south and central Mexico.
“It’s the white spots that seem to be the difference maker,” Davis says.
The researchers analyzed nearly 400 wild monarch wings collected at different stages of their journey, measuring their color proportions. They found the successful migrant monarchs had about 3% less black and 3% more white on their wings.
An additional analysis of museum specimens that included monarchs and six other butterfly species showed that the monarchs had significantly larger white spots than their nonmigratory cousins.
The only other species that came close to having the same proportion of white spots on its wing was its semi-migratory relative, the southern monarch.
The authors believe the butterflies’ coloring is related to the amount of radiation they receive during their journey. The monarchs’ longer journey means they’re exposed to more sunlight. As a result, they have evolved to have more white spots.
“The amount of solar energy monarchs are receiving along their journey is extreme, especially since they fly with their wings spread open most of the time,” Davis says. “After making this migration for thousands of years, they figured out a way to capitalize on that solar energy to improve their aerial efficiency.”
But as temperatures continue to rise and alter the solar radiation reaching Earth’s surface, monarchs will likely have to adapt to survive, says coauthor Mostafa Hassanalian, an associate professor at the New Mexico Institute of Mining and Technology.
“With greater solar intensity, some of that aerial efficiency could go away,” Davis says. “That would be yet one more thing that is hindering the species’ fall migration to Mexico.”
But it’s not all bad news for the flying insects.
Davis’ previous work showed that summer populations of monarchs have remained relatively stable over the past 25 years. That finding suggests that the species’ population growth during the summer compensates for butterfly losses due to migration, winter weather and changing environmental factors.
“The breeding population of monarchs seems fairly stable, so the biggest hurdles that the monarch population faces are in reaching their winter destination,” Davis says. “This study allows us to further understand how monarchs are successful in reaching their destination.”
Additional coauthors are from New Mexico Tech and the University of Georgia.
Source: University of Georgia
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Researchers report that water on Enceladus, one of Saturn’s moons, holds phosphates.
The team used data from NASA’s Cassini space mission to detect evidence of phosphates in particles ejected from the moon’s ice-covered global ocean.
Phosphorus, in the form of phosphates, is vital for all life on Earth. It forms the backbone of DNA and is part of cell membranes and bones. The new study in Nature is the first to report direct evidence of phosphorus on an extraterrestrial ocean world.
The team found that phosphate is present in Enceladus’ ocean at levels at least 100 times higher—and perhaps 1,000 times higher—than in Earth’s oceans.
“By determining such high phosphate concentrations readily available in Enceladus’ ocean, we have now satisfied what is generally considered one of the strictest requirements in establishing whether celestial bodies are habitable,” says third author Fabian Klenner, a postdoctoral researcher in Earth and space sciences at the University of Washington.
“This is the first finding of phosphorus on an extraterrestrial ocean world.”
While at Freie Universität Berlin, Klenner did experiments that revealed the high phosphate concentrations present in Enceladus’ ocean.
One of the most profound discoveries in planetary science over the past 25 years is that worlds with oceans beneath a surface layer of ice are common in our solar system. These ice-covered celestial bodies include the icy moons of Jupiter and Saturn—including Ganymede, Titan, and Enceladus—as well as even more distant celestial bodies, like Pluto.
NASA’s Cassini mission explored Saturn, its rings and its moons from 2004 to 2017. It first discovered that Enceladus’ harbors an ice-covered watery ocean, and analyzed material that erupted through cracks in the region of the moon’s south pole.
The spacecraft was equipped with the Cosmic Dust Analyzer that analyzed individual ice grains emitted from Enceladus and sent those measurements back to Earth. To determine the chemical composition of the grains, Klenner used a specialized setup in Berlin that mimicked the data generated by an ice grain hitting the instrument. He tried different chemical compositions and concentrations for his samples to try to match the unknown signatures in the spacecraft’s observations.
“I prepared different phosphate solutions, and did the measurements, and we hit the bullseye. This was in perfect match with the data from space,” Klenner says. “This is the first finding of phosphorus on an extraterrestrial ocean world.”
Planets with surface oceans, like Earth, must reside within a narrow range of distances from their host stars (in what is known as the “habitable zone“) to maintain temperatures at which water neither evaporates nor freezes. Worlds with an interior ocean like Enceladus, however, can occur over a much wider range of distances, greatly expanding the number of habitable worlds likely to exist across the galaxy.
In previous studies, the team at the Freie Universität Berlin determined that Enceladus harbors a “soda ocean,” rich in dissolved carbonates, that also contains a vast variety of reactive and sometimes complex carbon-containing compounds. The team also found indications of hydrothermal environments on the seafloor.
The new study now shows the unmistakable signatures of dissolved phosphates.
“Previous geochemical models were divided on the question of whether Enceladus’ ocean contains significant quantities of phosphates at all,” says lead author Frank Postberg at Freie Universität Berlin. “These measurements leave no doubt that substantial quantities of this essential substance are present in the ocean water.”
To investigate how the ocean on Enceladus can maintain such high concentrations of phosphate, geochemical lab experiments and modeling included in the new paper were conducted by a Japan-based team led by second author Yasuhito Sekine at the Tokyo Institute of Technology and a US-based team led by fourth author Christopher Glein at the Southwest Research Institute in San Antonio, Texas.
Source: University of Washington
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A new finding contradicts previous assumptions about the role of mobile plate tectonics in the development of life on Earth.
Scientists have used tiny mineral crystals called zircons to study plate tectonics billions of years ago. The research sheds light on the conditions that existed in early Earth, revealing a complex interplay among Earth’s crust, core, and the emergence of life.
Plate tectonics allows heat from Earth’s interior to escape to the surface, forming continents and other geological features necessary for life to emerge. Accordingly, “there has been the assumption that plate tectonics is necessary for life,” says John Tarduno, professor of geophysics at the University of Rochester. But new research casts doubt on that assumption.
Tarduno is lead author of a paper in Nature examining plate tectonics from a time 3.9 billion years ago, when scientists believe the first traces of life appeared on Earth. The researchers found that mobile plate tectonics was not occurring during this time. Instead, they discovered, Earth was releasing heat through what is known as a stagnant lid regime. The results indicate that although plate tectonics is a key factor for sustaining life on Earth, it is not a requirement for life to originate on a terrestrial-like planet.
“We found there wasn’t plate tectonics when life is first thought to originate, and that there wasn’t plate tectonics for hundreds of millions of years after,” says Tarduno. “Our data suggests that when we’re looking for exoplanets that harbor life, the planets do not necessarily need to have plate tectonics.”
The researchers didn’t set out to study plate tectonics.
“We were studying the magnetization of zircons because we were studying Earth’s magnetic field,” Tarduno says.
Zircons are tiny crystals containing magnetic particles that can lock in the magnetization of Earth at the time the zircons were formed. By dating the zircons, researchers can construct a timeline tracing the development of Earth’s magnetic field.
The strength and direction of Earth’s magnetic field change depending on latitude. For example, the current magnetic field is strongest at the poles and weakest at the equator. Armed with information about zircons’ magnetic properties, scientists can infer the relative latitudes at which the zircons formed. That is, if the efficiency of the geodynamo—the process generating the magnetic field—is constant and the intensity of the field is changing over a period, the latitude at which the zircons formed must also be changing.
But Tarduno and his team discovered the opposite: the zircons they studied from South Africa indicated that during the period from about 3.9 to 3.4 billion years ago, the strength of the magnetic field did not change, which means the latitudes did not change either.
Because plate tectonics includes changes in latitudes of various land masses, Tarduno says, “plate tectonic motions likely weren’t occurring during this time and there must have been another way Earth was removing heat.”
Further reinforcing their findings, the researchers found the same patterns in zircons they studied from Western Australia.
“We aren’t saying the zircons formed on the same continent, but it looks like they formed at the same unchanging latitude, which strengthens our argument that there wasn’t plate tectonic motion occurring at this time,” Tarduno says.
Earth is a heat engine, and plate tectonics is ultimately the release of heat from Earth. But stagnant lid tectonics—which results in cracks in Earth’s surface—are another means allowing heat to escape from the interior of the planet to form continents and other geological features.
Plate tectonics involves the horizontal movement and interaction of large plates on Earth’s surface. Tarduno and his colleagues report that, on average, plates from the last 600 million years have moved at least 8,500 kilometers (5,280 miles) in latitude. In contrast, stagnant lid tectonics describes how the outermost layer of Earth behaves like a stagnant lid, without active horizontal plate motion. Instead, the outer layer remains in place while the interior of the planet cools. Large plumes of molten material originating in Earth’s deep interior can cause the outer layer to crack. Stagnant lid tectonics is not as effective as plate tectonics at releasing heat from Earth’s mantle, but it can still lead to the formation of continents.
“Early Earth was not a planet where everything was dead on the surface,” Tarduno says. “Things were still happening on Earth’s surface; our research indicates they just weren’t happening through plate tectonics. We had at least enough geochemical cycling provided by the stagnant lid processes to produce conditions suitable for the origin of life.”
While Earth is the only known planet to experience plate tectonics, other planets, such as Venus, experience stagnant lid tectonics, Tarduno says.
“People have tended to think that stagnant lid tectonics would not build a habitable planet because of what is happening on Venus,” he says. “Venus is not a very nice place to live: it has a crushing carbon dioxide atmosphere and sulfuric acid clouds. This is because heat is not being removed effectively from the planet’s surface.”
Without plate tectonics, Earth may have met a similar fate. While the researchers hint that plate tectonics may have started on Earth soon after 3.4 billion years, the geology community is divided on a specific date.
“We think plate tectonics, in the long run, is important for removing heat, generating the magnetic field, and keeping things habitable on our planet,” Tarduno says. “But, in the beginning, and a billion years after, our data indicates that we didn’t need plate tectonics.”
Funding for the research came from the National Science Foundation.
Source: University of Rochester
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The world’s first transgenic ants have olfactory sensory neurons that flash green in response to odorants.
Ants navigate their richly aromatic world using an array of odor receptors and chemical signals called pheromones. Whether foraging or defending the nest, mating or tending to their young, ants both send and receive chemical signals throughout their lives. And the ant brain is well equipped to process the abundance of scents: The olfactory processing center in the ant’s brain has 10 times as many subdivisions as those of fruit flies, for example, even though their brains are about the same size.
And yet how the ant olfactory system encodes scent data has remained largely unknown.
Contrary to previous findings, the new study in Cell finds that only a few specific areas of the olfactory system lit up in response to alarm pheromones, danger signals that elicit panic and nest evacuation. The results raise questions about how sensory information is processed in the ant brain—as well as tantalizing possibilities for revealing what hundreds of other odorant receptors are up to.
“Neurogenetic tools have revolutionized the field of fruit fly neuroscience over the past decades, while social insect neuroscience has essentially been stuck,” says Daniel Kronauer, head of the Laboratory of Social Evolution and Behavior at Rockefeller University. “Our technical breakthroughs now finally allow us to apply these powerful tools in ants to study their social behavior.”
In 1958, E. O. Wilson reported that a secretion from the mandibular gland of harvester ants triggered their nestmates to quicken their pace and take up colony defense behaviors. He called this response “alarm behavior.” Since then, scientists have documented that alarm behavior and many other complex social activities in ant colonies are regulated by a vast array of pheromones.
Ants’ olfactory receptors are located on neurons in their antennae, which send their input to brain centers called the antennal lobes. The antennal lobes are comprised of specialized structures called glomeruli that are essential to scent processing. Some ants have more than 500 glomeruli—a bounty thought to be related to their heightened ability to perceive and discriminate between pheromones. Previous work from Kronauer’s lab has shown that ants whose odorant receptors have been knocked out cannot respond to pheromone signals.
In this study, the researchers created their transgenic subjects by injecting the eggs of clonal raider ants—a queenless species composed entirely of blind female workers—with genetic material encoding the synthetic protein GCaMP, which lights up neon green when calcium levels change during cellular activity.
“Our goal was to get GCaMP expressed only in a single cell type—the olfactory sensory neurons,” says lead author Taylor Hart, a researcher in Daniel Kronauer’s lab.
This was important because the antennal lobe is composed of multiple cell types: sensory neurons, projection neurons that carry sensory data to other parts of the brain, and lateral interneurons that link everything together. “Those other cell types can make signal-to-noise ratio poor, because they can be doing other activities, such as computations, processing information, and modulating signals,” Hart says. All of this can obscure what the olfactory neurons are doing.
While successfully breeding a small group of ants with GCaMP expression in the olfactory sensory neurons, the team also developed a sophisticated two-photon calcium imaging technique that allowed them to record neural activity throughout the entire antennal lobes of live ants for the first time.
The researchers decided to focus on alarm pheromones, because they are particularly volatile and elicit strong and robust behavioral responses. They found that adult ants that detected the scents immediately scrambled to gather as many eggs in their mandibles as they could and then made a break for it, fleeing into an adjacent section of the test chamber.
Hart and her team then used their new techniques to monitor GCaMP fluorescence levels in the antennal lobes of 22 transgenic ants as they exposed them to a range of odors, including the alarm pheromones (which smell fruity to the human nose). The flashes clustered in six glomeruli in one region, suggesting that area may act as the brain’s panic button.
“We were expecting that a large portion of the antennal lobe would show some kind of response to these alarm pheromones,” Hart says. “Instead, we saw that the responses were extremely localized. Most of the antennal lobe did not respond at all.”
Hart says the findings reveal details about how the ant brain processes sensory input. Researchers have wondered whether the activity is privatized, with each glomerulus responding only to one or a few specific stimuli, or distributed, with unique combinations of glomeruli activated by a stimulus. A brain with more than 500 glomeruli that operated in a distributed way, with hundreds of sensors firing at once, would need extraordinary computational power when it comes to sensory processing, Hart says.
“Most of the odors we tested activated only a small proportion of the total glomeruli,” she says. “It seems that privatization is the way in the ant antennal lobe.”
Considering that only six glomeruli responded out of 500, Hart wonders, “What do they need all these different glomeruli for? The fruit fly gets by with just 50.”
It will now be easier to find out why ants have a greater need to differentiate odor stimuli than other insects, Kronauer says—and not only because Hart has since bred hundreds of transgenic ants who differ from their wild counterparts only in their ability to signal in fluorescence, providing a robust pool for future research.
“The tools that Taylor developed open up a really big range of questions that were inaccessible to us until now,” he says. These include associating specific glomeruli with the variety of pheromones ants use for things like raiding, recruitment, and distinguishing between nestmates and outsiders. “There are also interesting developmental questions about how the ant olfactory system gets assembled, because it’s so complex. Larvae also have olfactory sensory neurons, so now we can look at their sensory capabilities.”
Source: Rockefeller University
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Scientists have developed a long-lasting battery made with nickel.
The discovery could reduce or even eliminate the use of cobalt in the batteries that power electric cars and other products.
Cobalt is often mined using child labor.
“Nickel doesn’t have child labor issues,” says Huolin Xin, professor of physics and astronomy at the University of California, Irvine.
The method could usher in a new, less controversial generation of lithium-ion batteries.
Until now, nickel wasn’t a practical substitute because large amounts of it were required to create lithium batteries, Xin says. And the metal’s cost keeps climbing.
To become an economically viable alternative to cobalt, nickel-based batteries needed to use as little nickel as possible.
“We’re the first group to start going in a low-nickel direction,” Xin says. “In a previous study by my group, we came up with a novel solution to fully eliminate cobalt. But that formulation still relied on a lot of nickel.”
To solve that problem, Xin’s team spent three years devising a process called “complex concentrated doping” that enabled the scientists to alter the key chemical formula in lithium-ion batteries as easily as one might adjust seasonings in a recipe.
The doping process, Xin explains, eliminates the need for cobalt in commercial components critical for lithium-ion battery functioning and replaces it with nickel.
“Doping also increases the efficiency of nickel,” says Xin, which means EV batteries now require less nickel to work—something that will help make the metal a more attractive alternative to cobalt-based batteries.
Xin says he thinks the new nickel chemistry will quickly start transforming the lithium-ion battery industry. Already, he says, electric vehicle companies are planning to take his team’s published results and replicate them.
“EV makers are very excited about low-nickel batteries, and a lot of EV companies want to validate this technique,” Xin says. “They want to do safety tests.”
The study appears in the journal Nature Energy.
Source: UC Irvine
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The discovery of tiny salt grains in an asteroid sample provides strong evidence that liquid water may be more common in the solar system’s largest asteroid population than previously thought.
The smattering of tiny salt crystals discovered in a sample from an asteroid has researchers excited, because these crystals can only have formed in the presence of liquid water.
Even more intriguing, according to the research team, is the fact that the sample comes from an S-type asteroid, a category known to mostly lack hydrated, or water-bearing, minerals. The discovery strongly suggests that a large population of asteroids hurtling through the solar system may not be as dry as previously thought. The finding, published in Nature Astronomy, gives renewed push to the hypothesis that most, if not all, water on Earth may have arrived by way of asteroids during the planet’s tumultuous infancy.
“Once these ingredients come together to form asteroids, there is a potential for liquid water to form.”
Tom Zega, the study’s senior author and a professor of planetary sciences at the the University of Arizona Lunar and Planetary Laboratory, and Shaofan Che, lead study author and a postdoctoral fellow at the Lunar and Planetary Laboratory, performed a detailed analysis of samples collected from asteroid Itokawa in 2005 by the Japanese Hayabusa mission and brought to Earth in 2010.
The study is the first to prove that the salt crystals originated on the asteroid’s parent body, ruling out any possibility they might have formed as a consequence of contamination after the sample reached Earth, a question that had plagued previous studies that found sodium chloride in meteorites of a similar origin.
“The grains look exactly like what you would see if you took table salt at home and placed it under an electron microscope,” Zega says. “They’re these nice, square crystals. It was funny, too, because we had many spirited group meeting conversations about them, because it was just so unreal.”
Zega says the samples represent a type of extraterrestrial rock known as an ordinary chondrite. Derived from so-called S-type asteroids such as Itokawa, this type makes up about 87% of meteorites collected on Earth. Very few of them have been found to contain water-bearing minerals.
“It has long been thought that ordinary chondrites are an unlikely source of water on Earth,” says Zega who is the director of the Lunar and Planetary Laboratory’s Kuiper Materials Imaging & Characterization Facility. “Our discovery of sodium chloride tells us this asteroid population could harbor much more water than we thought.”
Today, scientists largely agree that Earth, along with other rocky planets such as Venus and Mars, formed in the inner region of the roiling, swirling cloud of gas and dust around the young sun, known as the solar nebula, where temperatures were very high—too high for water vapor to condense from the gas, according to Che.
“In other words, the water here on Earth had to be delivered from the outer reaches of the solar nebula, where temperatures were much colder and allowed water to exist, most likely in the form of ice,” Che says. “The most likely scenario is that comets or another type of asteroid known as C-type asteroids, which resided farther out in the solar nebula, migrated inward and delivered their watery cargo by impacting the young Earth.”
The discovery that water could have been present in ordinary chondrites, and therefore been sourced from much closer to the sun than their “wetter” kin, has implications for any scenario attempting to explain the delivery of water to the early Earth.
The sample used in the study is a tiny dust particle spanning about 150 micrometers, or roughly twice the diameter of a human hair, from which the team cut a small section about 5 microns wide—just large enough to cover a single yeast cell—for the analysis.
Using a variety of techniques, Che was able to rule out that the sodium chloride was the result of contamination from sources such as human sweat, the sample preparation process, or exposure to laboratory moisture.
Because the sample had been stored for five years, the team took before and after photos and compared them. The photos showed that the distribution of sodium chloride grains inside the sample had not changed, ruling out the possibility that any of the grains were deposited into the sample during that time. In addition, Che performed a control experiment by treating a set of terrestrial rock samples the same as the Itokawa sample and examining them with an electron microscope.
“The terrestrial samples did not contain any sodium chloride, so that convinced us the salt in our sample is native to the asteroid Itokawa,” he says. “We ruled out every possible source of contamination.”
Zega says tons of extraterrestrial matter is raining down on Earth every day, but most of it burns up in the atmosphere and never makes it to the surface.
“You need a large enough rock to survive entry and deliver that water,” he says.
Previous work led by the late Michael Drake, a former director of the Lunar and Planetary Lab, in the 1990s proposed a mechanism by which water molecules in the early solar system could become trapped in asteroid minerals and even survive an impact on Earth.
“Those studies suggest several oceans worth of water could be delivered just by this mechanism,” Zega says. “If it now turns out that the most common asteroids may be much ‘wetter’ than we thought, that will make the water delivery hypothesis by asteroids even more plausible.”
Itokawa is a peanut-shaped near-Earth asteroid about 2,000 feet long and 750 feet in diameter and is believed to have broken off from a much larger parent body. According to Che and Zega, it is conceivable that frozen water and frozen hydrogen chloride could have accumulated there, and that naturally occurring decay of radioactive elements and frequent bombardment by meteorites during the solar system’s early days could have provided enough heat to sustain hydrothermal processes involving liquid water. Ultimately, the parent body would have succumbed to the pummeling and broken up into smaller fragments, leading to the formation of Itokawa.
“Once these ingredients come together to form asteroids, there is a potential for liquid water to form,” Zega says. “And once you have liquids form, you can think of them as occupying cavities in the asteroid, and potentially do water chemistry.”
The evidence pointing at the salt crystals in the Itokawa sample as being there since the beginning of the solar system does not end here, however. The researchers found a vein of plagioclase, a sodium-rich silicate mineral, running through the sample, enriched with sodium chloride.
“When we see such alteration veins in terrestrial samples, we know they formed by aqueous alteration, which means it must involve water,” Che says. “The fact that we see that texture associated with sodium and chlorine is another strong piece of evidence that this happened on the asteroid as water was coursing through this sodium-bearing silicate.”
Source: University of Arizona
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Astronomers are using NASA’s James Webb Space Telescope to peer deeper into the universe and farther back in time than ever before.
Already, the team has discovered hundreds of galaxies that existed when the universe was less than 600 million years old—just 4% of its current age.
The Webb Telescope, or JWST, also has observed galaxies sparkling with a multitude of young, hot stars formed during what researchers call “surprisingly episodic bursts of star formation.”
They made the observations as part of the JWST Advanced Deep Extragalactic Survey, or JADES, which is dedicated to uncovering and studying extremely faint, distant galaxies. Thirty-two days of observing time have been devoted to JADES, which is one of the largest observing programs in Webb’s first year of science.
The key to JWST’s ability to sniff out the extremely faint signatures of distant objects is its large, light-gathering mirror and infrared sensitivity.
“With JADES, we want to answer questions such as, ‘How did the earliest galaxies assemble themselves? How fast did they form stars? Why do some galaxies stop forming stars?'” says Marcia Rieke, a professor of astronomy at the University of Arizona Steward Observatory and a co-lead of the JADES program.
During his doctoral research at Steward Observatory, JADES team member Ryan Endsley, who is now a postdoctoral fellow at the University of Texas at Austin, led an investigation into galaxies that existed 500 to 850 million years after the Big Bang, a crucial time known as the “Epoch of Reionization.”
“Star formation in the early universe is much more complicated than we thought.”
For hundreds of millions of years, the young universe was filled with a gaseous fog that made it opaque to energetic light such as ultraviolet light or X-rays. About 1 billion years after the Big Bang, the fog had cleared and the universe became transparent during a process known as reionization.
Scientists have debated whether active, supermassive black holes or galaxies full of hot, young stars were the primary cause of reionization. As part of the JADES program, Endsley and his colleagues studied these galaxies specifically to look for signatures of star formation—and found them in abundance.
“Almost every single galaxy that we are finding shows these unusually strong emission line signatures indicating intense recent star formation,” Endsley says. “These early galaxies were very good at creating hot, massive stars.”
These bright, massive stars pumped out torrents of ultraviolet light, which transformed surrounding gas from opaque to transparent by ionizing atoms, unbinding their electrons from the nuclei. Since these early galaxies had such a large population of hot, massive stars, they may have been the main driver of the reionization process. The later reuniting of the electrons and nuclei produces the distinctively strong emission lines.
Endsley and his colleagues also found evidence that these young galaxies underwent periods of rapid star formation interspersed with quiet periods during which fewer stars formed. These fits and starts may have occurred as galaxies captured clumps of the gaseous raw materials needed to form stars. Alternatively, since massive stars are short-lived before they explode, they may have injected energy into the surrounding environment periodically, preventing gas from condensing to form new stars.
Another element of the JADES program involves the search for the earliest galaxies that existed when the universe was less than 400 million years old. By studying these galaxies, astronomers can explore how star formation in the early years after the Big Bang was different from today. The light from faraway galaxies is stretched to longer wavelengths and redder colors by the expansion of the universe—a phenomenon called redshift. By measuring a galaxy’s redshift, astronomers can learn how far away it is and, therefore, at what time it existed in the early universe.
“Before JWST, there were only a few dozen galaxies observed above a redshift of 8, when the universe was younger than 650 million years old, but JADES is now uncovering nearly a thousand of these extremely distant galaxies,” Rieke says.
The JADES team identified more than 700 candidate galaxies above redshift 8, which will completely overhaul astronomers’ understanding of early galaxy formation. The sheer number of these sources far exceeded predictions based on observations made before the launch of JWST. Webb’s fine resolution and sensitivity allow astronomers to get an unprecedented view of these distant galaxies.
“Previously, the earliest galaxies we could see just looked like little smudges,” says JADES team member Kevin Hainline, an assistant research professor at Steward Observatory. “And yet those smudges represent millions, or even billions, of stars at the beginning of the universe. Now, we can see, incredibly, that some of them are actually groupings of stars being born only a few hundred million years after the beginning of time.”
“What all this tells us,” Rieke says, “is that star formation in the early universe is much more complicated than we thought.”
The team presented their latest observations at the 242nd meeting of the American Astronomical Society in Albuquerque, New Mexico.
Source: University of Arizona
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African elephants use their acute sense of smell as a form of communication, researchers report.
Professor Louw Hoffman from the University of Queensland’s Queensland Alliance of Agriculture and Food Innovation co-led a study of elephants in wildlife parks in Malawi, which found that smell was used to distinguish characteristics including age, health, reproductive status, and family relationships between elephants.
“We tested the DNA, glands, urine, and manure of 113 African elephants to identify family groupings,” Hoffman says.
“We found a number of chemicals were common to group members, but others that were unique to each individual.
“Elephants never mate with a sibling, even if they’ve been separated for years and can tell a strange elephant is close by from the smell of their manure or other excretions.”
Hoffman says social behavior also suggests elephants use odor to monitor other pachyderms, both within and outside their herd.
“We observed elephants greeting each other by squealing and flapping their ears,” he says.
“We believe they’re pushing their pheromones towards the other elephant as a sign of recognition.
“When elephants charge each other flapping their ears, rather than making themselves look bigger, we believe they’re blowing their pheromones as a warning not to mess with them.”
Hoffman says elephants not only identify different smells quickly, but also retain them in their memory.
“Some of the animals in the study were bred in captivity, and one of the tricks they’d been taught was to take a tourist’s hat and smell it,” he says.
“When the tourist came back hours later the elephant would be able to immediately identify who the hat belonged to.”
Hoffman says elephants could be trained to sense many things, including blood and explosives.
“These findings show elephants are complex creatures, and sound is not their only form of communication,” he says.
“We see humans as the apex, but we now know elephants are one of many animals that have senses more finely attuned than ours.
“There is a lot we can learn from the elephant.”
The study was co-led by Katharina von Dürckheim and Alison Leslie from the University of Stellenbosch.
The research appears in Scientific Reports.
Source: University of Queensland
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It’s possible to retrieve forensically relevant information from human DNA in household dust, a new study finds.
After sampling indoor dust from 13 households, researchers were able to detect DNA from household residents over 90% of the time, and DNA from non-occupants 50% of the time. The work could be a way to help investigators find leads in difficult cases.
Specifically, the researchers were able to obtain single nucleotide polymorphisms, or SNPs, from the dust samples. SNPs are sites within the genome that vary between individuals—corresponding to characteristics like eye color—that can give investigators a “snapshot” of the person.
“SNPs are just single sites in the genome that can provide forensically useful information on identity, ancestry, and physical characteristics—it’s the same information used by places like Ancestry.com—that can be done with tests that are widely available,” says Kelly Meiklejohn, assistant professor of forensic science and coordinator of the forensic sciences cluster at North Carolina State University and corresponding author of the study in the Journal of Forensic Sciences.
“Because they’re single sites, they’re easier to recover for highly degraded samples where we may only be able to amplify short regions of the DNA,” Meiklejohn says.
“Traditional DNA analysis in forensics amplifies regions ranging from 100 to 500 base pairs, so for a highly degraded sample the large regions often drop out. SNPs as a whole don’t provide the same level of discrimination as traditional forensic DNA testing, but they could be a starting place in cases without leads.”
Meiklejohn and her team recruited 13 diverse households and took cheek swabs from each occupant along with dust samples from five areas within each home: the top of the refrigerator, inside the bedroom closet, the top frame of the front door, a bookshelf or photo frame in the living room, and a windowsill in the living room.
Utilizing massively parallel sequencing, or MPS, the team was able to quickly sequence multiple samples and target the SNPs of interest. They found that 93% of known household occupants were detected in at least one dust sample from each household. They also saw DNA from non-occupants in over half of the samples collected from each site.
“This data wouldn’t be used like traditional forensic DNA evidence—to link a single individual to a crime—but it could be useful for establishing clues about the ancestry and physical characteristics of individuals at a scene and possibly give investigators leads in cases where there may not be much to go on,” Meiklejohn says.
“But while we know it is possible to detect occupants versus non-occupants, we don’t know how long an individual has to stay in a household before they leave DNA traces in household dust.”
The researchers plan to address the question of how much time it takes for non-occupants to be detected in dust in future studies. Meiklejohn sees the work as being useful in numerous potential investigative scenarios.
“When perpetrators clean crime scenes, dust isn’t something they usually think of,” Meiklejohn says. “This study is our first step into this realm. We could see this being applied to scenarios such as trying to confirm individuals who might have been in a space but left no trace blood, saliva, or hair. Also for cases with no leads, no hit on the national DNA database, could household dust provide leads?”
The NC State College of Veterinary Medicine funded the work. Additional coauthors are from Massachusetts Institute of Technology and NC State.
Source: NC State
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New research clarifies how the brain goes to great lengths to process and remember everyday events.
Researchers used functional MRI scanners to monitor the brains of subjects watching short videos of scenes that could have come from real life. These included people working on laptops in a cafe or shopping in a grocery store.
“They were very ordinary scenes,” says Zachariah Reagh, an assistant professor of psychological and brain sciences at Washington University in St. Louis. “No car chases or anything.”
The research subjects then immediately described the scenes with as much detail as they could muster. The mundane snippets led to intriguing findings, including that different parts of the brain worked together to understand and remember a situation.
Networks in the front part of the temporal lobe, a region of the brain long known to play an important role in memory, focused on the subject regardless of their surroundings. But the posterior medial network, which involves the parietal lobe toward the back of the brain, paid more attention to the environment. Those networks then sent information to the hippocampus, Reagh explains, which combined the signals to create a cohesive scene.
Researchers had previously used very simple objects and scenarios—such as a picture of an apple on a beach—to study the different building blocks of memories, Reagh says. But life isn’t so simple, he says. “I wondered if anyone had done these types of studies with dynamic real-word situations and, shockingly, the answer was no.”
The new study in Nature Communications suggests that the brain makes mental sketches of people that can be transposed from one location to another, much like an animator can copy and paste a character into different scenes. “It may not seem intuitive that your brain can create a sketch of a family member that it moves from place to place, but it’s very efficient,” he says.
Some subjects could recall the scenes in the café and grocery store more completely and accurately than others. Reagh and coauthor Charan Ranganath of the University of California, Davis, found that those with the clearest memories used the same neural patterns when recalling scenes that they used while watching the clips. “The more you can bring those patterns back online while describing an event, the better your overall memory,” he says.
At this time, Reagh says, it’s unclear why some people seem more adept than others at reproducing the thought patterns needed to access memory. But it’s clear that many things can get in the way. “A lot can go wrong when you try to retrieve a memory,” he says.
Even memories that seem crisp and vivid may not actually reflect reality. “I tell my students that your memory is not a video camera. It doesn’t give you a perfect representation of what happened. Your brain is telling you a story,” he says.
In future, Reagh plans to study the brain activity and memory of people watching more complicated stories.
Source: Washington University in St. Louis
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Astrocytes may be a key player in the brain’s ability to process external and internal information simultaneously, according to a new study.
Long thought of as “brain glue,” the star-shaped cells called astrocytes are members of a family of cells found in the central nervous system called glial that help regulate blood flow and synaptic activity, keep neurons healthy, and play an important role in breathing.
Despite this growing appreciation for astrocytes, much remains unknown about the role these cells play in helping neurons and the brain process information.
“We believe astrocytes can add a new dimension to our understanding of how external and internal information is merged in the brain,” says Nathan Smith, associate professor of neuroscience at the Del Monte Institute for Neuroscience at the University of Rochester.
“More research on these cells is necessary to understand their role in the process that allows a person to have an appropriate behavioral response and also the ability to create a relevant memory to guide future behavior.”
The way our body integrates external with internal information is essential to survival. When something goes awry in these processes, behavioral or psychiatric symptoms may emerge.
Smith and coauthors point to evidence that astrocytes may play a key role in this process. Previous research has shown astrocytes sense the moment neurons send a message and can simultaneously sense sensory inputs. These external signals could come from various senses such as sight or smell.
Astrocytes respond to this influx of information by modifying their calcium Ca2+ signaling directed towards neurons, providing them with the most suitable information to react to the stimuli.
The authors hypothesize that this astrocytic Ca2+ signaling may be an underlying factor in how neurons communicate and what may happen when a signal is disrupted. But much is still unknown in how astrocytes and neuromodulators, the signals sent between neurons, work together.
“Astrocytes are an often-overlooked type of brain cell in systems neuroscience,” Smith says. “We believe dysfunctional astrocytic calcium signaling could be an underlying factor in disorders characterized by disrupted sensory processing, like Alzheimer’s and autism spectrum disorder.”
Smith has spent his career studying astrocytes. As a graduate student at the University of Rochester School of Medicine and Dentistry, Smith was part of the team who discovered an expanded role for astrocytes. Apart from absorbing excess potassium, astrocytes themselves could cause potassium levels around the neuron to drop, halting neuronal signaling. This research showed, for the first time, that astrocytes did more than tend to neurons, they also could influence the actions of neurons.
“I think once we understand how astrocytes integrate external information from these different internal states, we can better understand certain neurological diseases. Understanding their role more fully will help propel the future possibility of targeting astrocytes in neurological disease,” Smith says.
The communication between neurons and astrocytes is far more complicated than previously thought. Evidence suggests that astrocytes can sense and react to change—a process that is important for behavioral shifts and memory formation.
The study authors believe discovering more about astrocytes will lead to a better understanding of cognitive function and lead to advances in treatment and care.
The study appears in Trends in Neuroscience.
Additional coauthors are from the University of Copenhagen.
The National Institutes of Health, the National Science Foundation, the European Union under the Marie Skłodowska-Curie Fellowship, the ONO Rising Star Fellowship, the Lundbeck Foundation Experiment Grant, and the Novo Nordisk Foundation supported the work.
Source: University of Rochester
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New research digs into when and how horses spread and flourished in the western US.
Until now, the accepted theory of horses arriving to the Great Plains and Northern Rockies was shaped by word of mouth and lore.
The new research, published in Science, establishes the expansion of the domesticated horse through DNA evidence.
The researchers compared genetic samples from horse remains at archeological sites to the genetics of rare, early horse breeds similar to those that came over with early settlers. They found familial ties indicating that horses arrived with Europeans and then made their way west during the 17th century. Horses were not out west 10,000 years ago when nomadic people first arrived in North America.
Some archaeological evidence like bones, horseshoes, and colonial items have been found in various locations across the US and occasionally in deposits west of the Mississippi. However, when it came to whether horses were always in the western US or if they came over with Europeans and Spaniards and made it from the East Coast to the Rockies, horses left an open book.
Horses themselves and horsemanship seemed to have spread west faster than Europeans did, the researchers also found. Some of the early horse fossils showed horses were established in the Great Plains before the European and Spanish made their way west. More research needs to be done to understand just how this happened, but it’s another fascinating finding.
Besides filling in some blanks in the history books, this research has real implications for how horses are selected for breeding today.
“We can see aspects of genetic selection from 3,000 years ago that are likely important for a good temperament and a strong back in our horses today,” says Samantha Brooks, associate professor of equine genetics at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) whose lab collected DNA samples for the study and helped analyze the data.
“Those are things horse people still struggle with today. The more we learn about genetics that control those aspects of horse health, the better off we can take care of our horses today.”
The new findings shed light on the role horses played in Indigenous cultures. Horses have been a significant part of many Native American cultures, but this research clarifies when and how horses were integrated into their lives.
“European nations valued the horse, but horses did not become a life changing cultural icon to them as it did to the Indigenous people,” Brooks. “The horse suited the nomadic plains lifestyle so remarkably well.”
Nomadic people may not have made it to North America 10,000 years ago with horses in hand, but somehow their way of life was so well suited to the horse that once it arrived in the western US plains, it thrived as part of the Native American culture.
“Some tribal historians thought it was possible that the horses found out west were genetically distinct from the lineage that arrived with Spanish and European colonizers, but the data showed that is unlikely,” says Brooks.
“This is almost a more remarkable finding. The level of skill the Native peoples have with horse handling and management is truly impressive, and this study tells us that they developed that skill in a relatively short amount of time.”
One of the fossilized horses used in the study was found to have sustained a skull fracture at some point in its life that was unrelated to its later death. An injury like that would have almost certainly required supportive care in order to survive, a testament to how tough these early horses had to be, and to how well Indigenous communities cared for the animals.
“Native people adapted and flourished as a horse culture in the blink of a historical eye,” says Brooks.
The researchers thank the Livestock Conservancy and owners and breeders of rare horse breeds such as the Galiceño, Marsh Tacky, and Florida Cracker Horse that contributed genetic samples to the study. Without those samples, this research would not have been possible.
Source: University of Florida
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Research in the jungle of New Guinea reveals two species of birds that carry a powerful neurotoxin.
“These birds contain a neurotoxin that they can both tolerate and store in their feathers,” says Knud Jønsson of the Natural History Museum of Denmark, who worked with Kasun Bodawatta of the University of Copenhagan.
The bird species have each developed the ability to consume toxic food and turn that into a poison of their own.
The species in question are the regent whistler (Pachycephala schlegelii), a species that belongs to a family of birds with a wide distribution and easily recognizable song well known across the Indo-Pacific region, and the rufous-naped bellbird (Aleadryas rufinucha).
“We were really surprised to find these birds to be poisonous as no new poisonous bird species has been discovered in over two decades. Particularly, because these two bird species are so common in this part of the world,” says Jønsson. The findings appear in the journal Molecular Ecology.
Most people are familiar with South and Central America’s iconic poison dart frogs—especially the golden poison frog. These small, brightly colored amphibians can kill a human at the slightest touch. The discovery of the same type of toxin in birds’ skin and feathers demonstrates that the frog toxin is more widespread than once believed.
“It’s a bit like cutting onions—but with a nerve agent, I guess.”
The poison is called Batrachotoxin. It’s an incredibly potent neurotoxin that, in higher concentrations leads to muscle cramps and cardiac arrest nearly immediately after contact.
“The bird’s toxin is the same type as that found in frogs, which is a neurotoxin that, by forcing sodium channels in skeletal muscle tissue to remain open, can cause violent convulsions and ultimately death,” explains Bodawatta.
South America’s poison dart frogs use their toxin to protect them from predators. Though the level of toxicity of the New Guinean birds is less lethal, it may still serve a defensive purpose, but the adaptive significance for the birds is yet uncertain.
“Knud thought I was sad and having a rough time on the trip when they found me with a runny nose and tears in my eyes. In fact, I was just sitting there taking feather samples from a Pitohui, one of the most poisonous birds on the planet. Removing birds from the net isn’t bad, but when samples need to be taken in a confined environment, you can feel something in your eyes and nose. It’s a bit like cutting onions—but with a nerve agent, I guess,” laughs Bodawatta.
“The locals aren’t fond of spicy food and steer clear of these birds, because, according to them, their meat burns in the mouth like chili. In fact, that’s how researchers first became aware of them. And the toxin can be felt when holding onto one of them. It feels kind of unpleasant and hanging on to one for long isn’t an appealing option. This could indicate that the poison serves them as a deterrence of those who would want to eat them to some degree,” explains Jønsson.
There is a distinction in biology between the two ways that animals deploy poisons. There are poisonous animals that produce toxins in their bodies and others that absorb toxins from their surroundings. Like the frogs, the birds belong to the latter category. Both are believed to acquire toxins from what they eat. Beetles containing the toxin have been found in the stomachs of some of the birds. But the source of the toxin itself has yet to be determined.
What makes it possible for these birds to have a toxin in their bodies without themselves being harmed? The researchers studied this with inspiration from poison dart frogs, whose genetic mutations prevent the toxin from keeping their sodium channels open, and thereby preventing cramps.
“So, it was natural to investigate whether the birds had mutations in the same genes. Interestingly enough, the answer is yes and no. The birds have mutations in the area that regulates sodium channels, which we expect gives them this ability to tolerate the toxin, but not in the exact same places as the frogs,” says Bodawatta.
He adds: “Finding these mutations that can reduce the binding affinity of Batrathotoxin in poisonous birds in similar places as in poison dart frogs, is quite cool. And it showed that in order to adapt to this Batrachotoxin lifestyle, you need some sort of adaptation in these sodium channels”.
Therefore, these studies of the birds Multiple mutations in the Nav1.4 sodium channel of New Guinean toxic birds provide autoresistance to deadly batrachotoxin establish that while their neurotoxin is similar to that of the South American poison dart frogs, the birds developed their resistance and ability to carry it in the bodies independently of the frogs. This is an example of what biologists refer to as convergent evolution.
This basic research will primarily contribute to a better understanding of New Guinea’s birds and how different animal species not only acquire a resistance to toxins but use them as a defense mechanism.
Other aspects of the research have the potential to help ordinary people. The toxin conquered by the birds over time is closely related to other toxins, such as the one responsible for shellfish poisoning.
“Obviously, we are in no position to claim that this research has uncovered the holy grail of shellfish poisoning or similar poisonings, but as far as basic research, it is a small piece of a puzzle that can help explain how these toxins work in cells and in the body. And, how the bodies of certain animals have evolved to tolerate them,” says Jønsson
Source: University of Copenhagen
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The recent discovery of a sabertooth cat skull in southwest Iowa is the first evidence the prehistoric predator once inhabited the state.
The chance of finding any fossilized remains from a sabertooth cat is slim, says Matthew Hill, an associate professor of archaeology at Iowa State and expert on animal bones. The remarkably well-preserved skull found in Page County is even rarer, and its discovery offers clues about the iconic Ice Age species before its extinction roughly 12-13,000 years ago.
“The skull is a really big deal,” says Hill. “Finds of this animal are widely scattered and usually represented by an isolated tooth or bone. This skull from the East Nishnabotna River is in near perfect condition. It’s exquisite.”
Hill analyzed the specimen in collaboration with David Easterla, professor emeritus of biology at Northwest Missouri State University. Their findings appear in the journal Quaternary Science Reviews.
The researchers used radiocarbon dating to determine the cat died at the end of the Ice Age between 13,605 and 13,460 years ago. Hill says it may have been one of the last sabertooths to walk the planet as glaciers receded and temperatures rose.
“We think southwest Iowa during this period was a parkland with patches of trees interspersed with grassy openings, somewhat similar to central Canada today,” says Hill. “The cat would have lived alongside other extinct animals like dire wolf, giant short-faced bear, long-nosed peccary, flat-headed peccary, stag-moose, muskox, and giant ground sloth, and maybe a few bison and mammoth.”
Hill and Easterla believe the skull belonged to a subadult (2-3 year old) male when it died. Gaps between the skull’s boney plates indicate its head was still growing, and the permanent teeth don’t show much wear from cutting and chewing. To figure out its sex, they compared its skull measurements with adult male and female sabertooth skulls from the Rancho La Brea tar pits in Los Angeles.
Hill explains sabertooth were sexually dimorphic, meaning males were larger than females. Since the Iowa skull is larger than many male skulls from the tar pits, the researchers argue it belonged to a male. They estimate the Iowa cat weighed about 550 pounds at death and may have approached 650 pounds as an adult in prime physical condition. In comparison, the average adult male African lion weighs about 400 pounds.
How the sabertooth cat died is not clear. But a broken canine might offer a clue. Hill and Easterla speculate the animal was seriously injured while attacking prey, which ultimately proved fatal within days of the trauma.
Small patches of worn-down bone on top of the skull indicate it slid along a river-bottom before coming to rest and then buried for thousands of years.
“We can learn a lot from these types of fossils. They hold clues about the ecology of the animals, and how they respond to dramatic climate change and the appearance of a new predator and competitor on the landscape, including people,” says Hill. “Iowa is a fantastic laboratory to do research on extinct Ice Age animals and the people who were just beginning to share the landscape with them.”
Research opportunities with the sabertooth cat skull don’t end with the published analysis, the researchers say.
Hill suspects the cat’s primary prey was Jefferson’s giant ground sloth, which were common in Iowa during the Ice Age. They’d sit beside trees and bushes and pull in leaves and buds to eat. At 8-to-10 feet tall and over 2,200 pounds, giant ground sloths were massive. Hill believes only a large predator armed with “absolutely lethal jaws and claws” and legs designed for pouncing could hunt them regularly.
To test this, Hill is teaming up with Andrew Somerville, assistant professor of archaeology at Iowa State who is an expert in dietary reconstruction using bone geochemistry. Together, they’re developing a stable isotope mixing model with samples from the sabertooth cat, other carnivores, and herbivores (e.g., Jefferson’s ground sloth, muskox, stag-moose.)
“You are what you eat, and it’s locked in your bones,” says Hill.
Stable isotopes make it possible for researchers to know what plants herbivores eat and, in turn, what herbivores carnivores eat. They can piece together local food webs and how species filled ecological niches.
“So, maybe the sabertooth was primarily eating giant ground sloth, dire wolves, primarily moose, and short-faced bears, a little bit of everything. Andrew and I are going to figure it out,” says Hill.
The researchers expect to publish their findings in the coming year.
Source: Iowa State University
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New research digs into how runners stay upright on uneven or bumpy terrain.
If you go running over a trail in the woods or a grassy field, there are countless bumps and dips in the terrain, each with the potential to trip you up. But typically, runners manage just fine. It’s a remarkable physical feat that we tend to take for granted, but researchers may have some answers.
With a specially made running track and mathematical modeling, the lab of Madhusudhan Venkadesan found that when running on uneven terrain, humans mostly rely on the body’s mechanical response for stability rather than consciously plot out their footsteps to find level ground.
Further, the researchers found that the runners were just as efficient in their movements and physical exertion as when running on flat ground.
The findings appear in eLife.
Even without occasional hazards like steep drops, runners must contend with gentler, but still uneven ground that can be destabilizing. So why aren’t trails typically littered with toppled runners?
One possibility is that visual cues allow runners to carefully observe the land to step on mostly level areas. On the other hand, running played a huge role in human evolution, particularly in how it benefited humans in hunting. That means sight cannot be devoted solely to find areas to step on; it’s also needed to watch out for the prey, trees, or other obstacles to avoid, and decide which path to take.
“Imagine running and constantly looking at the ground right in front of you to decide where to place your step,” says Venkadesan, associate professor of mechanical engineering and materials science at Yale University. “You can’t be devoting all your attention just to that problem, because your vision is needed for many things.”
Because an actual trail in the woods doesn’t have the controlled conditions necessary for a scientific study, Venkadesan commissioned the construction of an uneven trackway from a company that specializes in climbing walls.
The researchers heuristically designed different levels of unevenness of the terrain to mimic the kind of uneven trail that outdoor runners often encounter. They outfitted the 70-foot-long, 3-foot-wide track with technology that can track and measure where on the terrain the runners’ feet were landing. This included a sensor in one area part of the track to measure the forces experienced by the foot.
“With this, we could measure in a few of those steps how forces are felt by the runner,” he says. “In addition, we measured key landmarks on the body using 3D-motion capture. So we could ask, what does the center of mass movement look like? Are they meandering around and trying to find a path, or just going straight down the middle?”
Nihav Dhawale, a recently graduated PhD student from Venkadesan’s lab, developed a mathematical model of a runner who would try to find the most level path through the uneven bumps, while still matching the runner’s step length and width. This model would ask whether there’s a feasible path through the trackway that can minimize the unevenness, and thus ask whether the real runners find that path.
As it turns out, the runners weren’t choosy about where they put their feet.
“What we found was people appear to land their feet wherever they like,” Venkadesan says. “They don’t seem to care about the unevenness.”
So, in that case, how do runners manage to stay upright? The researchers found that, rather than trying to find specific level areas, the runners minimized the horizontal forces experienced when they land, and therefore used their body’s intrinsic mechanics to reduce the destabilizing influence of the terrain’s unevenness.
The mathematical modeling showed that the runners kept their legs as compliant as they could, and doing so allowed them to minimize the horizontal forces when their feet touched down (that is, the sliding, scuffing forces upon impact). The same authors had predicted in an older paper that low horizontal forces would drastically mitigate the instability associated with running on uneven terrain. As a result, the runner has several steps to make small corrections to regain full stability.
“The corrective action doesn’t have to occur in milliseconds or within a single step,” Venkadesan says. “It could occur over a few steps, and that’s adequate to maintain stability. So in a sense, we are letting the mechanical response of our body buy the brain extra time to control stability.”
Source: Yale University
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Scientists have created a new map of 85,000 volcanoes on Venus.
“This paper provides the most comprehensive map of all volcanic edifices on Venus ever compiled,” says Paul Byrne, an associate professor of earth and planetary sciences at Washington University in St. Louis.
“It provides researchers with an enormously valuable database for understanding volcanism on that planet—a key planetary process, but for Venus is something about which we know very little, even though it’s a world about the same size as our own.”
Byrne and Rebecca Hahn, a graduate student in earth and planetary sciences, used radar imagery from NASA’s Magellan mission to Venus to catalog volcanoes across the planet at a global scale. Their resulting database contains 85,000 volcanoes, about 99% of which are less than 3 miles (5 km) in diameter.
“Since NASA’s Magellan mission in the 1990s, we’ve had numerous major questions about Venus’ geology, including its volcanic characteristics,” Byrne says. “But with the recent discovery of active volcanism on Venus, understanding just where volcanoes are concentrated on the planet, how many there are, how big they are, etc., becomes all the more important—especially since we’ll have new data for Venus in the coming years.”
“We came up with this idea of putting together a global catalog because no one’s done it at this scale before,” says Hahn, first author of the paper in JGR Planets. “It was tedious, but I had experience using ArcGIS software, which is what I used to build the map. That tool wasn’t available when these data first became available back in the ’90s. People back then were manually hand-drawing circles around the volcanoes, when I can just do it on my computer.”
“This new database will enable scientists to think about where else to search for evidence of recent geological activity,” says Byrne, who is a faculty fellow of the university’s McDonnell Center for the Space Sciences. “We can do it either by trawling through the decades-old Magellan data (as the new Science paper did) or by analyzing future data and comparing it with Magellan data.”
The new study includes detailed analyses of where volcanoes are, where and how they’re clustered, and how their spatial distributions compare with geophysical properties of the planet such as crustal thickness.
Taken together, the work provides the most comprehensive understanding of Venus’ volcanic properties—and perhaps of any world’s volcanism so far.
That’s because, although we know a great deal about the volcanoes on Earth that are on land, there are still likely a great many yet to be discovered under the oceans. Lacking oceans of its own, Venus’ entire surface can be viewed with Magellan radar imagery.
Although there are volcanoes across almost the entire surface of Venus, the scientists found relatively fewer volcanoes in the 20-100 km diameter range, which may be a function of magma availability and eruption rate, they surmise.
Byrne and Hahn also wanted to take a closer look at smaller volcanoes on Venus, those less than 3 miles across that have been overlooked by previous volcano hunters.
“They’re the most common volcanic feature on the planet: they represent about 99% of my dataset,” Hahn says. “We looked at their distribution using different spatial statistics to figure out whether the volcanoes are clustered around other structures on Venus, or if they’re grouped in certain areas.”
The new volcanoes dataset is publicly available for other scientists to use.
“We’ve already heard from colleagues that they’ve downloaded the data and are starting to analyze it—which is exactly what we want,” Byrne says. “Other people will come up with questions we haven’t, about volcano shape, size, distribution, timing of activity in different parts of the planet, you name it. I’m excited to see what they can figure out with the new database!”
And if 85,000 volcanoes on Venus seems like a large number, Hahn says it’s actually conservative. She believes there are hundreds of thousands of additional geologic features that have some volcanic properties lurking on the surface of Venus. They’re just too small to get picked up.
“A volcano 1 kilometer in diameter in the Magellan data would be 7 pixels across, which is really hard to see,” Hahn says. “But with improved resolution, we could be able to resolve those structures.”
And it’s exactly that kind of data that future missions to Venus will acquire in the 2030s.
“NASA and ESA (the European Space Agency) are each sending a mission to Venus in the early 2030s to take high-resolution radar images of the surface,” Byrne says. “With those images, we’ll be able to search for those smaller volcanoes we predict are there.
“This is one of the most exciting discoveries we’ve made for Venus—with data that are decades old!” Byrne says. “But there are still a huge number of questions we have for Venus that we can’t answer, for which we have to get into the clouds and onto the surface.
“We’re just getting started,” he says.
Source: Washington University in St. Louis
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A team of researchers propose using the James Webb Space Telescope to look at five planets in the Venus Zone, a search that could reveal valuable insights into Earth’s future.
Venus floats in a nest of sulfuric acid clouds, has no water, and its surface temperatures are hot enough to melt lead. Despite being such a scorching wasteland, however, the planet is often referred to as Earth’s sister because of similarities in size, mass, density, and volume.
Earth and Venus, which both formed about 4.5 billion years ago, now sit on opposite ends of habitability. This leaves astronomers with a giant question: Is Venus Earth’s past or Earth’s future?
“It’s all about trying to understand why Earth and Venus are so different now,” says Jim Head, a professor of geological sciences at Brown University. “We have Venus to look at here, but there are solar systems out there in which we can actually compare all these different things that we want to know. It’s a whole new parameter of space to explore.”
In the study in the Astronomical Journal, Held and colleagues identify five Venus-like planets from a list of more than 300. The researchers selected these terrestrial planets orbiting other stars, called exoplanets, because they were the most likely to resemble Venus in terms of their radii, masses, densities, the shapes of their orbits, and distances from their stars.
The researchers rank the Venus-like planets depending on the brightness of the stars they orbit to increase the odds that the Webb Telescope gets the clearest view of them, enabling researchers to pull key signals from them regarding the composition of their atmospheres.
The five planets all orbit regions called the Venus Zone, which was coined by astrophysicist and study coauthor Stephen Kane from the University of California, Riverside.
The Venus Zone encompasses the region around a star where it’s too hot for a planet to have water but not too hot for it to have no atmosphere. It is similar to the concept of a habitable zone, which is a region around a star where liquid surface water could exist.
The researchers propose the planets identified in the paper as targets for the Webb telescope in 2024. Webb is NASA’s most ambitious telescope to date and is enabling scientists not only to look into the deep past of the universe but to peer into the atmospheres of exoplanets for telltale signs of what the planet is like.
Studying exoplanets in the Venus Zone could give astronomers a better understanding of whether Venus was ever habitable. The Webb observations the researchers propose, for example, may reveal biosignature gases in the atmosphere such as methane, methyl bromide, or nitrous oxide, which could signal the presence of life. The researchers also hope to see through the observations whether Venus’s lack of plate tectonics is common and whether the planet’s volcanic activity is normal.
These observations will be complemented by NASA’s two upcoming spacecraft missions to Venus. The DAVINCI mission will measure gases in the Venusian atmosphere. The VERITAS mission will enable 3D reconstructions of the landscape.
Combined, the findings will help lead to a better understanding of the Earth-Venus divergence, which could serve as a dire warning for where Earth is heading, the researchers say.
Colby Ostberg, a UC Riverside PhD student, is the study’s lead author. NASA’s Habitable Worlds Program supported the work.
Source: Brown University
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