Beer lovers could be left with a sour taste, thanks to the latest in a series of studies mapping the effects of climate change on crops.
Malted barley — a key ingredient in beer including IPAs, stouts and pilsners — is particularly sensitive to warmer temperatures and drought, both of which are likely to increase due to climate change. As a result, average global barley crop yields could drop as much as 17 percent by 2099, compared with the average yield from 1981 to 2010, under the more extreme climate change projections, researchers report October 15 in Nature Plants. That decline “could lead to, on average, a doubling of price in some countries,” says coauthor Steven Davis, an Earth systems scientist at University of California, Irvine. Consumption would also drop globally by an average of 16 percent, or roughly what people in the United States consumed in 2011.
The results are based on computer simulations projecting climate conditions, plant responses and global market reactions up to the year 2099. Under the mildest climate change predictions, world average barley yields would still go down by at least 3 percent, and average prices would increase about 15 percent, the study says.
Other crops such as maize, wheat and soy and wine grapes are also threatened by the global rising of average atmospheric temperatures as well as by pests emboldened by erratic weather (SN: 2/8/14, p. 3). But there’s still hope for ale aficionados. The study did not account for technological innovations or genetic tweaks that could spare the crop, Davis says.
17th century scientist Christiaan Huygens set his sights on faraway Saturn, but he may have been nearsighted.
Huygens is known, in part, for discovering Saturn’s largest moon, Titan, and deducing the shape of the planet’s rings. But by some accounts, the Dutch scientist’s telescopes produced fuzzier views than others of the time despite having well-crafted lenses.
That may be because Huygens needed glasses, astronomer Alexander Pietrow proposes March 1 in Notes and Records: the Royal Society Journal of the History of Science. To make his telescopes, Huygens combined two lenses, an objective and an eyepiece, positioned at either end of the telescope. Huygens experimented with different lenses to find combinations that, to his eye, created a sharp image, eventually creating a table to keep track of which combinations to use to obtain a given magnification. But when compared with modern-day knowledge of optics, Huygens’ calculations were a bit off, says Pietrow, of the Leibniz Institute for Astrophysics Potsdam in Germany.
One possible explanation: Huygens selected lenses based on his flawed vision. Historical records indicate that Huygens’ father was nearsighted, so it wouldn’t be surprising if Christiaan Huygens also suffered from the often-hereditary affliction.
Assuming that’s the reason for the mismatch, Pietrow calculates that Huygens had 20/70 vision: What someone with normal vision could read from 70 feet away, Huygens could read only from 20 feet. If so, that could be why Huygens’ telescopes never quite reached their potential.
When the [Atomic Energy Commission] first cast its eye on the island of Amchitka as a possible site for the testing of underground nuclear explosions, howls of anguish went up; the island is part of the Aleutians National Wildlife Refuge, created to preserve the colonies of nesting birds and some 2,500 sea otters that live there…— Science News, November 9, 1968
Update The commission said underground nuclear testing would not harm the otters, but the fears of conservationists were well-founded: A test in 1971 killed more than 900 otters on the Aleutian island. Some otters remained around Amchitka, but 602 otters were relocated in 1965–1972 to Oregon, southeast Alaska, Washington and British Columbia — areas where hunting had wiped them out. All but the Oregon population thrived, and today more than 25,000 otters live near the coastal shores where once they were extinct.
“They were sitting on the precipice,” says James Bodkin, who is a coastal ecologist at the U.S. Geological Survey. “It’s been a great conservation story.”
Neandertals are shaking off their reputation as head bangers.
Our close evolutionary cousins experienced plenty of head injuries, but no more so than late Stone Age humans did, a study suggests. Rates of fractures and other bone damage in a large sample of Neandertal and ancient Homo sapiens skulls roughly match rates previously reported for human foragers and farmers who have lived within the past 10,000 years, concludes a team led by paleoanthropologist Katerina Harvati of the University of Tübingen in Germany. Males suffered the bulk of harmful head knocks, whether they were Neandertals or ancient humans, the scientists report online November 14 in Nature.
“Our results suggest that Neandertal lifestyles were not more dangerous than those of early modern Europeans,” Harvati says.
Until recently, researchers depicted Neandertals, who inhabited Europe and Asia between around 400,000 and 40,000 years ago, as especially prone to head injuries. Serious damage to small numbers of Neandertal skulls fueled a view that these hominids led dangerous lives. Proposed causes of Neandertal noggin wounds have included fighting, attacks by cave bears and other carnivores and close-range hunting of large prey animals.
Paleoanthropologist Erik Trinkaus of Washington University in St. Louis coauthored an influential 1995 paper arguing that Neandertals incurred an unusually large number of head and upper-body injuries. Trinkaus recanted that conclusion in 2012, though. All sorts of causes, including accidents and fossilization, could have resulted in Neandertal skull damage observed in relatively small fossil samples, he contended (SN: 5/27/17, p. 13). Harvati’s study further undercuts the argument that Neandertals engaged in a lot of violent behavior, Trinkaus says.
Still, the idea that Neandertals frequently got their heads bonked during crude, close-up attacks on prey has persisted, says paleoanthropologist David Frayer of the University of Kansas in Lawrence. The new report highlights the harsh reality that, for Neandertals and ancient humans alike, “head trauma, no matter the level of technological or social complexity, or population density, was common.”
Harvati’s group analyzed data for 114 Neandertal skulls and 90 H. sapiens skulls. All of these fossils were found in Eurasia and date to between around 80,000 and 20,000 years ago. One or more head injuries appeared in nine Neandertals and 12 ancient humans. After statistically accounting for individuals’ sex, age at death, geographic locations and state of bone preservation, the investigators estimated comparable levels of skull damage in the two species. Statistical models run by the team indicate that skull injuries affected an average of 4 percent to 33 percent of Neandertals, and 2 percent to 34 percent of ancient humans.
Estimated prevalence ranges that large likely reflect factors that varied from one locality to another, such as resource availability and hunting conditions, the researchers say.
Neandertals with head wounds included more individuals under age 30 than observed among their human counterparts. Neandertals may have suffered more head injuries early in life, the researchers say. It’s also possible that Neandertals died more often from head injuries than Stone Age humans did.
Researchers have yet to establish whether Neandertals experienced especially high levels of damage to body parts other than the head, writes paleoanthropologist Marta Mirazón Lahr of the University of Cambridge in a commentary in Nature accompanying the new study.
THE WOODLANDS, TEXAS — Martian dirt may have all the necessary nutrients for growing rice, one of humankind’s most important foods, planetary scientist Abhilash Ramachandran reported March 13 at the Lunar and Planetary Science Conference. However, the plant may need a bit of help to survive amid perchlorate, a chemical that can be toxic to plants and has been detected on Mars’ surface (SN: 11/18/20).
“We want to send humans to Mars … but we cannot take everything there. It’s going to be expensive,” says Ramachandran, of the University of Arkansas in Fayetteville. Growing rice there would be ideal, because it’s easy to prepare, he says. “You just peel off the husk and start boiling.” Ramachandran and his colleagues grew rice plants in a Martian soil simulant made of Mojave Desert basalt. They also grew rice in pure potting mix as well as several mixtures of the potting mix and soil simulant. All pots were watered once or twice a day.
Rice plants did grow in the synthetic Mars dirt, the team found. However, the plants developed slighter shoots and wispier roots than the plants that sprouted from the potting mix and hybrid soils. Even replacing just 25 percent of the simulant with potting mix helped heaps, they found.
The researchers also tried growing rice in soil with added perchlorate. They sourced one wild rice variety and two cultivars with a genetic mutation — modified for resilience against environmental stressors like drought — and grew them in Mars-like dirt with and without perchlorate (SN: 9/24/21).
No rice plants grew amid a concentration of 3 grams of perchlorate per kilogram of soil. But when the concentration was just 1 gram per kilogram, one of the mutant lines grew both a shoot and a root, while the wild variety managed to grow a root.
The findings suggest that by tinkering with the successful mutant’s modified gene, SnRK1a, humans might eventually be able to develop a rice cultivar suitable for Mars.
A new design for sun-powered desalination technology may lead to longer-lasting devices that produce cleaner water.
The trick boils down to preventing a device’s components from touching the saltwater. Instead, a lid of light-absorbing material rests above a partially filled basin of water, absorbing sunlight and radiating that energy to the liquid below. That evaporates the water to create pure vapor, which can be condensed into freshwater to help meet the demands of a world where billions of people lack safe drinking water (SN: 8/18/18, p. 14). This setup marks an improvement over other sun-powered desalination devices, where sunshine-absorbing materials float atop the saltwater (SN: 8/20/16, p. 22). In those devices, salt and other contaminants left behind during evaporation can degrade the material’s ability to soak up sunlight. Having water in contact with the material also prevents the material from getting hotter than about 100° Celsius or producing steam above that temperature. That limits the technology’s ability to purify the final product; killing pathogenic microbes often requires temperatures of at least 121° C.
In the new device, described online December 11 in Nature Communications, the separation between the light-absorbing lid and the water’s surface helps keep the lid clean and allows it to generate vapor tens of degrees hotter than the water’s boiling point.
The lid comprises three main components: a top layer made of a metal-ceramic composite that absorbs sunshine, a sheet of carbon foam and a bottom layer of aluminum. Heat spreads from the sunlight-absorbing layer to the aluminum, from which thermal energy radiates to the water below. When the water temperature hits about 100° C, vapor is produced. The steam rises up through holes in the aluminum and flows through the lid’s middle carbon layer, heating further along the way, until it is released in a single stream out the side of the lid. There, it can be captured and condensed.
Producing superheated steam in this way, without any gunk buildup, is “a very innovative idea,” says Jia Zhu, a materials scientist at Nanjing University in China not involved in the work. Under a lamp that mimics natural sunlight in the lab, the device evaporated 100 grams of saltwater without any salt collecting on the underside of the lid. Salt crystals formed at the bottom of the basin washed away easily. In experiments in October on a rooftop in Cambridge, Mass., researchers used a curved mirror to focus incoming sunlight onto the light-absorbing layer of the device to produce steam hotter than 146° C.
“When you can access these temperatures, you can use the steam for things like sterilization, for cooking, for cleaning, for industrial processes,” says coauthor Thomas Cooper, a mechanical engineer at York University in Toronto. A device measuring 1 square meter could generate 2.5 liters of freshwater per day in sunny regions such as the southeastern United States, and at least half that in shadier regions such as New England, Cooper estimates.
This sun-powered technology could also provide an ecofriendly alternative to reverse osmosis, a water purification process that involves pushing seawater through salt-filtering membranes (SN: 9/15/18, p. 10). Reverse osmosis, which runs on electricity, “is an energy-hungry technology,” says Qiaoqiang Gan, an engineer at the University at Buffalo in New York not involved in the work. “For resource-limited areas, remote areas or people who live on small islands, this [new device] might be a very good option for them to address their freshwater needs.” But researchers still need to investigate how affordable a commercial version of this device would be, Gan says.
SAN DIEGO — Labs growing replicas of snakes’ venom glands may one day replace snake farms.
Researchers in the Netherlands have succeeded in growing mimics of venom-producing glands from multiple species of snakes. Stem cell biologist Hans Clevers of the Hubrecht Institute in Utrecht, the Netherlands, reported the creation of these organoids on December 10 at a joint meeting of the American Society for Cell Biology and the European Molecular Biology Organization.
If scientists can extract venom from the lab-grown glands, that venom might be used to create new drugs and antidotes for bites including from snakes that aren’t currently raised on farms.
Up to 2.7 million people worldwide are estimated to be bitten by venomous snakes each year. Between about 81,000 to 138,000 people die as a result of the bite, and as many as roughly 400,000 may lose limbs or have other disabilities, according to the World Health Organization. Antivenoms are made using venom collected from snakes usually raised on farms. Venom is injected into other animals that make antibodies to the toxins. Purified versions of those antibodies can help a bitten person recover, but must be specific to the species of snake that made the bite. “If it’s a fairly rare or local snake, chances are there would be no antidote,” Clevers says.
Three postdoctoral researchers in Clevers’ lab wanted to know if they could make organoids — tissues grown from stem cells to have properties of the organs they mimic — from snakes and other nonmammalian species. The researchers started with Cape coral snakes (Aspidelaps lubricus) that were dissected from eggs just before hatching. Stem cells taken from the unhatched snakes grew into several different types of organoids, including some that make venom closely resembling the snake’s normal venom, Clevers reported at the meeting.
His team has produced venom-gland organoids from at least seven species of snakes. The organoids have survived in the lab for up to two years so far.
Clevers and colleagues hope to harvest venom from the organoids, which produce more highly concentrated venom than snakes usually make. “It’s probably going to be easier than milking a snake,” he says.
Satellites may be a more accurate way to track smog-producing ammonia.
It’s notoriously tricky to pinpoint accurate numbers for ammonia gas emissions from sources such as animal feedlots and fertilizer plants. But new maps, generated from infrared radiation measurements gathered by satellites, reveal global ammonia hot spots in greater detail than before. The new data suggest that previous estimates underestimate the magnitude of these emissions, researchers report December 5 in Nature.
In the atmosphere, ammonia, which contains nitrogen, can help form tiny particles that worsen air quality and harm human health. The research could help keep tabs on who’s emitting how much, to make sure that factories and farms are meeting environmental standards. Emissions are usually estimated by adding up output from individual known sources of activity, but those calculations are only as good as the data that go into them. Ammonia sticks around only hours to a few days in the atmosphere, so on-the-ground measurements vary a lot even in the same place, says coauthor Martin Van Damme, an atmospheric scientist at the Université Libre de Bruxelles in Belgium.
“There’s so much uncertainty in ammonia emissions,” says Daven Henze, a mechanical engineer at the University of Colorado Boulder who wasn’t part of the research. Other scientists, including his research group, have estimated ammonia releases using satellite data before. But these new maps rely on a more detailed dataset and have substantially better resolution, Henze says — fine enough that the study authors were able to link areas of high emissions to specific factories or farms. The new maps show 248 nitrogen emission hot spots across the globe at a resolution of about a kilometer. Eighty-three of those hot spots arose from agricultural activity that involved high numbers of cows, pigs and chickens, such as a site in Colorado that overlapped on satellite imagery maps with two big cattle feedlots. Ammonia emissions from feedlots come largely from livestock waste. Another 158 sites were affected by industrial emissions — mostly from sites that produced ammonia-based fertilizer, such as in Marvdasht, Iran. Six hot spots couldn’t be pinned to specific activity. Ammonia is also emitted naturally, from volcanoes or seabird colonies. But most of those sources were too weak or not concentrated enough to show up as hot spots in the data. Lake Natron in Tanzania is the one exception — its mud flats show up as an ammonia-releasing hot spot, perhaps due to decaying algae. But it’s not clear why other lakes with similar mud flats didn’t. Some natural sources may have gone undetected because of where they were located — in places with heavy cloud cover that obscured the data, or where turbulent air dissipated ammonia especially quickly, Van Damme suggests.
Some areas with particularly high overall ammonia emissions from biomass burning or fertilizer, such as West Africa and the Indus Valley in Pakistan and northern India, didn’t reveal specific hot spots, either, the researchers report.
Scientists are taking aim at the physics of rubber band bombardments.
Using high-speed video, researchers have analyzed what happens to a rubber band when it’s launched from a thumb. The results offer some tips for how to make a clean shot, Boston University mechanical engineers Alexandros Oratis and James Bird report in a paper in press in Physical Review Letters.
The researchers focused on one particular shooting technique: Elastic is slung around the raised thumb of one hand and pulled back with the fingers of the other hand. Standardizing the operation by using a cylinder rather than a thumb, the scientists filmed the details of the shooting process.
When the rubber band is let loose, a release of tension in the band quickly travels toward the cylinder. Meanwhile, the band itself zings toward the cylinder at a slower speed than that tension release, the scientists found.
When shot off a thumb, the band’s forward motion could lead to a rubbery rear-ender, with the thumb getting in the way of the elastic and sending the band askew. But if the feat is performed properly, the release of tension causes the thumb to duck out of the way before the rubber band reaches it. The band then sails past, buckling into a wrinkly shape as it shoots by.
By testing different shooting strategies, the researchers zeroed in on some guidelines. Don’t pull the band too tight: The extra tension increases the flight speed, so the thumb doesn’t deflect fast enough to avoid it. And a wider elastic band is preferred. That’s because the thumb must exert more force against the wider band, so that when the band is released, the digit falls away more quickly, making the elastic’s getaway easier.
While searching for shipwreck remains near Oman in the Arabian Sea in 2014, divers discovered an unusual metal disk that has since proven to be the world’s oldest known mariner’s astrolabe, British researchers report.
The navigational device came from the wreckage of a ship in the Portuguese armada that had been part of explorer Vasco da Gama’s second voyage to India from 1502 to 1503. Historical decorations on the artifact led the researchers to suggest that the disk was used as early as 1496. A bit wider than a dollar bill, the astrolabe contains carvings of Portugal’s royal coat of arms and a depiction of a ringed Earth that was associated with a Portuguese king who ruled from late 1495 to 1521. Laser imaging of the disk revealed 18 scale marks separated at 5-degree intervals.
The device, used to take altitudes at sea, could have measured from 0 degrees — when the sun is at the horizon — to 90 degrees — when the sun is directly overhead, the team reports in a study published online March 16 in the International Journal of Nautical Archaeology. Only one other solid disk, mariner’s astrolabe has been found, and its authenticity and age are uncertain, say oceanographer David Mearns and colleagues. Mearns directs Blue Water Recoveries in Midhurst, England, a company that locates and studies shipwrecks.
Of 104 artifacts known to have been used as mariner’s astrolabes, the new find is not only the oldest, but also the only one decorated with a national symbol, the researchers say. By the early 1500s, most navigators had adopted more precise, open-wheeled astrolabes.
