Food insecurity risk to rise as a result of global warming

April 2 (UPI) — According to a new study, rising global temperatures will threaten many populations’ access to affordable, nutritious food.

Global warming, or climate change, is expected to increase the frequency of extreme weather events, including droughts and floods.

“Such weather extremes can increase vulnerability to food insecurity,” Richard Betts, a professor of climate science at the University of Exeter, said in a news release.

Betts and his colleagues designed a model to measure the impact of global warming of 1.5 and 2 degrees Celsius on extreme weather patterns and food insecurity in 122 developing nations, mostly in Asia, Africa and South America.

While an increased risk of flooding could curb agricultural yields in some parts of the world, prolonged droughts are the more threatening of the two weather extremes.

Drought risks are likely to be most pronounced in southern Africa and South America, while Asia could be at greater risk of flooding. If global temperatures rise by 2 degrees Celsius, the flow of the River Ganges could more than double.

Both extreme flooding and prolonged droughts could curb populations’ access to clean drinking water, as well as food.

The new analysis, published this week in the journal Philosophical Transactions of the Royal Society A, suggests food security risks can be minimized by curbing greenhouses gas emissions and slowing global warming.

“Some change is already unavoidable, but if global warming is limited to 1.5 degree Celsius, this vulnerability is projected to remain smaller than at 2 degrees Celsius in approximately 76 percent of developing countries,” Betts said.

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Sea turtles use their flippers to play with their food, researchers say

March 28 (UPI) — Though the flippers of sea turtles evolved to aid locomotion, new research shows the reptiles use them to play with their food, too. In fact, the survey of marine tetrapods suggests food manipulation with flippers is common.

“Sea turtles don’t have a developed frontal cortex, independent articulating digits or any social learning,” Kyle Van Houtan, director of science at Monterey Bay Aquarium, said in a news release. “And yet here we have them ‘licking their fingers’ just like a kid who does have all those tools. It shows an important aspect of evolution — that opportunities can shape adaptations.”

Inspired by her studies of sea otters and their tool usage, aquarium research Jessica Fujii wanted to find out whether sea turtles use their flippers in similar ways. Fujii and her colleagues crowdsourced images and video of sea turtles all over the globe using their flippers to manipulate food.

One clip featured a loggerhead rolling a scallop on ocean floor, while another showed a hawksbill pressing against a reef for support while it pulled an anemone loose.

Food manipulation with flippers has been documented in otters, seals, walruses and manatees, but the study — published this week in the journal PeerJ — is the first to highlight the behavior in sea turtles.

“Sea turtles’ limbs have evolved mostly for locomotion, not for manipulating prey,” Fujii said. “But that they’re doing it anyway suggests that, even if it’s not the most efficient or effective way, it’s better than not using them at all.”

Researchers were surprised to find the behavior so prevalent among sea turtles. Not only do they rely on relatively small and simple brains, they also spend no time with their parents. Unlike marine mammals, newborn turtles aren’t taught to forage by their parents.

“It’s amazing that they’re figuring out how to do this without any apprenticing, and with flippers that aren’t well adapted for these tasks,” Van Houtan said.

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Scientists stunned by discovery of galaxy without dark matter

March 28 (UPI) — Most galaxies are defined by their dark matter. To study dark matter — and affirm its existence — astronomers study galaxies.

Now, for the first time, scientists have found a galaxy without dark matter — NGC1052-DF2’s dark matter is missing. When astronomers first found the dark matter-less galaxy, they were stunned.

“For decades, we thought that galaxies start their lives as blobs of dark matter,” Pieter van Dokkum of Yale University said in a news release. “After that everything else happens: gas falls into the dark matter halos, the gas turns into stars, they slowly build up, then you end up with galaxies like the Milky Way. NGC1052-DF2 challenges the standard ideas of how we think galaxies form.”

The galaxy is an ultra-diffuse galaxy, it’s large and faint, and is located 65 million light-years away. Though ultra-diffuse galaxies were only recently discovered, they are relatively common. But NGC1052-DF2 is the first to be found without dark matter.

“NGC1052-DF2 is an oddity, even among this unusual class of galaxy,” said Yale grad student Shany Danieli.

Astronomers were first alerted to the galaxy’s strange composition when they noticed discrepancies in the observations made by the Dragonfly Telephoto Array and the Sloan Digital Sky Survey. The Dragonfly images revealed a faint, blob-like object, while SDSS renderings showed a collection of bright point-like sources.

To further explore the discrepancy and study the unusual internal structure of NGC1052-DF2, astronomers observed the galaxy using the Gemini Multi Object Spectrograph, Keck’s Deep Imaging Multi-Object Spectrograph and Low-Resolution Imaging Spectrometer.

“Without the Gemini images dissecting the galaxy’s morphology we would have lacked context for the rest of the data,” said Danieli. “Also, Gemini’s confirmation that NGC1052-DF2 is not currently interacting with another galaxy will help us answer questions about the conditions surrounding its birth.”

The Keck data showed the point-like sources, the globules, were moving much slower than astronomers expected. The movement and speed of a galaxy’s components allow scientists to measure the galaxy’s mass. Astronomers determined the galaxy’s stars accounted for all of NGC1052-DF2’s estimated mass. There was no dark matter to be found.

Researchers described their discovery in the journal Nature.

“If there is any dark matter at all, it’s very little,” van Dokkum said. “The stars in the galaxy can account for all of the mass, and there doesn’t seem to be any room for dark matter.”

No one is really sure how the galaxy formed without dark matter.

The presence of the nearby giant elliptical galaxy NGC 1052, home to violent galactic formation and evolution, could explain NGC1052-DF2’s lack of dark matter. It’s also possible a sudden burst of stellar formation swept away the galaxy’s gas and dark matter, stunting its development.

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Spiders, scorpions use leg genes to grow their heads

March 26 (UPI) — Arachnids don’t need specialized genes to develop a head. According to a new study published this week in the journal PNAS, they simply use their leg genes.

University of Wisconsin-Madison researchers Emily Setton and Prashant Sharma were searching for the evolutionary origins of spinnerets, the organs that allow spiders to spin silk threads. To suss out genetic links between spinnerets and spiders’ legs, the researchers silenced leg development genes in arachnid embryos. When they did so, the tiny spiders not only failed to develop legs, they also failed to grow heads.

“Evolution doesn’t want to reinvent the wheel,” Setton said in a news release.

Followup analysis showed both spiders and scorpions use the genes Sp6-9 and Dll to manage head development. The genes code for leg development in most arthropods.

It’s not the first time scientists have found the same genes serving a variety of purposes across different species. For example, the same gene is used to code for jaw bones in reptiles and ear bones in humans.

The latest discovery is, however, a reminder of the evolutionary efficiency of the arthropod, a group that’s adapted to land, water and air. Setton and Sharma believe arthropods hold many of the secrets of genetic evolution and adaptation.

“We study spiders, scorpions and others to help build a more complete evolutionary story and look at what’s going on in the complex world of arthropods,” said Setton.

The researchers hope more of their genetic tricks will be revealed by the phylum’s many unusual members.

“We work with really difficult animals to study,” Sharma said. “A big question of the lab is how is diversity built genetically, evolutionarily? How are ancient lineages related, and what are the genetic mechanisms that underlie the differences between them?”

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'Invisible' display: Cal researchers design atomically-thin, light-emitting device

March 26 (UPI) — Engineers have developed a light-emitting display so thin it disappears when turned off.

The device, designed by scientists at the University of California, Berkeley, was built using a monolayer semiconductor and measures just three-atoms thick.

“The materials are so thin and flexible that the device can be made transparent and can conform to curved surfaces,” Der-Hsien Lien, a postdoctoral fellow at Cal, said in a news release.

In 2015, Ali Javey, a professor of electrical engineering and computer sciences at Berkeley, published research showing monolayer semiconductors are capable of emitting bright light. The latest research, published this week in the journal Nature Communications, expands on Javey’s work.

Scientists working in Javey’s lab were able to overcome a number of technological barriers and scale-up monolayer semiconductor technology described in 2015 by several orders of magnitude. By scaling-up the technology, researchers were able to stretch the semiconductor’s lateral dimensions enough to create a display capable of emitting bright light.

Light-emitting semiconductors require a pair of “contacts,” or inputs, to deliver a negative and positive charge. This necessity has limited the ability of engineers to shrink the thickness of semiconductor displays.

The new ultra thin device designed by Berkeley researchers features only a single contact. By laying the semiconductor monolayer on an insulator embedded with electrodes, engineers were able to deliver an AC current that switches from positive to negative. The two charges move simultaneously through the semiconductor, causing the device to emit light.

The proof-of-concept device is not very energy efficient, but with future improvements, scientists hope the technology could pave the way for an invisible smart display that could be installed on walls and windows — or even used to create light-up tattoos.

“A lot of work remains to be done and a number of challenges need to be overcome to further advance the technology for practical applications,” Javey said. “However, this is one step forward by presenting a device architecture for easy injection of both charges into monolayer semiconductors.”

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Researchers investigate if Hurricane Harvey helped fire ants spread in Texas

March 26 (UPI) — Scientists at Rice University are trying to measure the impact of Hurricane Harvey on fire ant populations, an invasive species common throughout the South.

Previous studies suggest invasive species take over and thrive in damaged ecosystems. Hurricane Harvey offered ecologists another chance to test the theory.

“Hurricane Harvey was, among other things, a grand ecological experiment,” Rice ecologist Tom Millersaid in a news release. “It offers a unique opportunity to explore whether a single extreme-weather event can re-shuffle an entire community of organisms.”

With support from the National Science Foundation’s Rapid Response Research, Miller and his colleagues are conducting monthly surveys of fire ant and tawny crazy ant populations in Big Thicket, a heavily forested national preserve in southeast Texas. Scientists at Rice had been monitoring research sites in Big Thicket for three years prior to the arrival of Hurricane Harvey, noting the steady encroachment of the two invasive ant species.

“We now want to know whether Harvey accelerated this invasion process,” said researcher Sarah Bengston.

In addition to measuring species’ abundance and distribution, researchers will also collect and analyze genetic samples to determine whether Hurricane Harvey proved advantageous for certain traits.

“There are dozens of native ant species in the preserve that provide valuable ecosystem services like decomposition and pest control,” ecologist Scott Solomon said. “Fire ants and crazy ants, which are each native to South America, are noxious invasive pests that tend to overwhelm and drive out almost all native ant species. If the floods cleaned the slate by drowning all the native ant colonies in the area, our hypothesis is that this may provide a competitive advantage to invaders.”

There wasn’t much ant activity during this year’s cold winter, but as temperatures warm, the insects will reemerge.

The research is similar to work being carried out by scientists at the University of Oklahoma. Researchers there continue to monitor the impacts of historic flooding on insect and invertebrate communities in south-central Oklahoma. The early results of their efforts showed the flood caused a sharp decrease in abundance, as well as declines in species presence, biomass and diversity.

As extreme weather evens become more common due to climate change, it is important for scientists to understand how local ecosystems will be affected.

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