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New eDNA technique may reduce pathogens in international aquatic animal trade

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June 24 (UPI) — A Washington State University researcher has developed new ways to detect the genetic signatures of disease in the international aquatic animal trade.

The methods call for the screening of environmental DNA, or eDNA — genetic material collected from the environment — not an animal’s cells, according to a study published Wednesday in the journal Scientific Reports.

Bats and livestock aren’t the only animals carrying potentially harmful diseases — fish and amphibians can also carry zoonotic pathogens.

With aquaculture now the fastest growing sector of animal protein production, the international trade of aquatic animals could pose a growing threat to human health. Diseases transported through the international pet trade can also threaten native fish and amphibian populations.

Every year, 225 million live animals are imported into the United States. Screening all of these animals individually would be cost and labor prohibitive, researchers say.

To tackle the problem, researcher Jesse Brunner, a professor of disease ecology at Washington State, developed a pair of more efficient screening methods.

According to Brunner, test samples could be batched before analysis. Scientists could also survey water samples from animal tanks for the presence of dangerous pathogens.

“The best way to prevent the emergence of these pathogens, and the diseases that come from them, is to keep them from getting here in the first place,” Brunner said in a news release. “It’s an important goal but a really hard one because of the scale of the problem. With the eDNA method, you are theoretically sampling an entire population at once, so you are more likely to detect whatever is there, and you can do that much more efficiently than with traditional approaches.”

Like humans, animals infected with pathogens shed pieces of the virus or invading bacteria. These DNA fragments will end up in the water in which they’re living.

Batrachochochytrium salamandrivorans, or Bsal, is one of the pathogens that scientists could use eDNA screening methods to detect, researchers say.

The fungus is a major threat to amphibian species. It was recently introduced to native salamander populations in Europe by pets imported from Southeast Asia. In 2016, the U.S. Fish and Wildlife Service banned the importation of 201 species of salamanders into the United States.

In her paper, Brunner used statistical formulas to determine the volume of samples that would need to be analyzed in order to be confident that imported animals were free of harmful pathogens.

Researchers are currently using real samples to test the efficacy and efficiency of Brunner’s screening methods.

“The problem that we’re having with amphibians is also the same problem that we’re having with all sorts of wildlife and with human disease,” said Brunner. “I think if we can solve this problem, we’ll be in much better shape to solve others.”



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Evidence of biodiversity losses found deep inside the rainforest

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Oct. 26 (UPI) — After decades of studying Amazonian ecosystems, scientists at Louisiana State University realized they were seeing fewer and fewer birds that forage on and near the forest floor.

“What we think is happening is an erosion of biodiversity, a loss of some of the richness in a place where we would hope biodiversity can be maintained,” Philip Stouffer, professor of conservation biology at LSU, said in a news release.

Since 1991, Stouffer has been leading research expeditions into some of the most remote parts of the Amazon rainforest, north of Manaus, Brazil. Around 2008, he and his graduate students started noticing that some of the birds they used to see in abundance were becoming hard to find.

Researchers set out to quantify their observations, collecting detailed observation data from 55 test sites. With the help of computer models, researchers compared their observations to datasets spanning 35 years.

Stouffer and company detailed their analysis in a new paper published Monday in the journal Ecology Letters.

“It’s a very robust dataset from a variety of places collected over many years. It’s not just some fluke,” said study co-author Stephen Midway.

“It looks like there’s a real pattern and it looks like it could be linked to things we know are happening with global climate change that are affecting even this pristine place,” said Midway, an assistant professor at LSU and an expert in computation biology.

The data showed the decline of floor-foraging birds has been slow but steady — and could have been easily overlooked.

“Our nostalgia was correct — certain birds are much less common than they used to be,” Stouffer said. “If animal patterns are changing in the absence of landscape change, it signals a sobering warning that simply preserving forests will not maintain rainforest biodiversity.”

Researchers found that bird species that have declined the most are those living and foraging near the forest floor, birds that feed on insects and small invertebrates — species like the wing-banded antbird, or Myrmornis torquata. The new data showed one of the Amazon’s most adept singers, the musician wren, or Cyphorinus arada, has suffered steady declines over the last three decades.

The white-plumed antbird, or Pithys albifrons, is one of the few floor foragers that remains easy to find. Scientists suspect its ingenious foraging technique has aided the species’ resiliency.

The white-plumed antbird follows colonies of marauding ants as they scare up other insects from soil, and it can adapt to different parts of the forest and eat a variety of insects.

Scientists also observed increases in the number of frugivores, or birds that eat fruit and insects, which suggests species with more diverse diets are better able to adapt to ecological shifts.

Stouffer plans to continue investigating the hidden signs of biodiversity loss in seemingly pristine portions of the Amazon.

“The idea that things are changing, even in the most pristine parts of our planet yet we don’t even know it, illustrates the need for us to pay more attention,” Stouffer said.



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NASA announces discovery of water on moon’s sunlit surface

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Oct. 26 (UPI) — Lunar water isn’t relegated to the dark side of the moon. On Monday, NASA announced that scientists had discovered water molecules inside Clavius Crater, a massive lunar depression visible from Earth.

The discovery, detailed in the journal Nature Astronomy, was made possible by NASA’s research aircraft SOFIA, short for Stratospheric Observatory for Infrared Astronomy.

Researchers previously found concentrations of hydrogen on the moon’s sunlit surface, but were unable to determine their origin.

“Today, we’re announcing the previously detected hydrogen found on the surface of the moon is located in water molecules,” Paul Hertz, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters, told reporters Monday during a teleconference.

SOFIA measured water concentrations of 100 to 412 parts per million. For comparison, the Sahara Desert hosts water concentrations 100 times greater.

But the discovery raises new questions about the abundance and distribution of water on the moon, which scientists previously believed to be exclusively locked up in polar ice caps and at the bottom of only the moon’s deepest craters.

Because the moon has such a thin atmosphere, any unprotected water on the sunlit surface of the moon should be quickly lost to space, and yet, scientists have not found irrefutable evidence that the water molecules are there.

How it gets there and what keeps it there remain open questions, researchers said.

NASA’s announcement was made in conjunction with the publication of a second study in Nature Astronomy, showing tiny permanently shadowed cold traps may house small patches of water ice all over the moon’s surface.

NASA scientists are keen to understand the moon’s hydrological dynamics as they prepare for human missions to the moon. Astronauts need water to drink, of course, but water can also be used to synthesize oxygen, make fuel, water plants and more.

If there is a sustainable source of water on the moon, that makes packing for long stays on the moon a lot easier.

“It’s far easier to travel when don’t have to carry everything with you that you might need once you’re there,” Jacob Bleacher, chief exploration scientist for NASA’s Human Exploration and Operations Mission Directorate, said during the teleconference. “You can be much more efficient with what you pack.”

“Water is heavy, therefore is expensive to launch from the surface if we don’t have take water with us,” Bleacher said. “We have an opportunity to take other things with us, for instance, payloads to do more science.”

NASA plans to continue using SOFIA’s instruments to look for water on sunlight portions of the lunar surface, but to solve the mysteries of the moon’s water supply, it’s likely more direct lunar exploration will be necessary, the scientists said.



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Moon’s smallest shadows may be hiding tiny patches of water ice

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Oct. 26 (UPI) — Water ice may be more abundant on the moon’s surface than previously thought.

New research, published Monday in the journal Nature Astronomy, suggests tiny patches of ice may be hiding inside lunar shadows as a small as a penny.

“If you can imagine standing on the surface of the moon near one of its poles, you would see shadows all over the place,” Paul Hayne, an assistant professor of astrophysical and planetary sciences at the University of Colorado, said in a news release. “Many of those tiny shadows could be full of ice.”

Hayne and his colleagues suggest many of the moon’s smallest shadows are permanent. Scientists predict many of these darkened pockets of the lunar surface, or “cold traps,” haven’t been hit with a ray of sunlight in billions of years.

“If we’re right, water is going to be more accessible for drinking water, for rocket fuel, everything that NASA needs water for,” said Hayne.

For a bigger example of a cold trap, the study’s authors looked to Shackleton Crater, a massive depression on the moon’s southern pole. Because much of crater remains permanently darkened, temperatures inside the 13-mile-wide depression remain a steady minus 300 degrees Fahrenheit all year long.

“The temperatures are so low in cold traps that ice would behave like a rock,” Hayne said. “If water gets in there, it’s not going anywhere for a billion years.”

To see how common cold traps are, researchers collected a wealth of data on the contours of the lunar surface and used models to simulate what the moon looks like at small scales. Their analysis showed the lunar surface is a lot like a golf ball, covered in tiny dimples.

The models showed many of these tiny bumps, ridges and crests are capable of keeping small portions of the lunar surface in permanent shadow. Though simulations suggest most of the moon’s cold traps measure no more than a centimeter wide, they combine to create 7,000 square miles of permanent shadow.

Scientists can’t be sure that these tiny cold traps hold water ice. To find out, a lunar mission will be necessary.

The finding was announced the same day NASA confirmed water molecules on the sunlit surface of the moon.

The discovery, researchers said, needs to be confirmed — the atmosphere of the moon is so thin that water molecules should be quickly lost to space, so how they would remain on the surface is unknown.

But finding water resources will be essential to establishing a human presence on the moon, they said.

If the cold traps identified by Hayne and his colleagues do indeed hold water, and water molecules are found across the sunlit side of the moon, NASA may have more flexibility in where they can base their human missions.



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