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How children are spoofing Covid-19 tests with soft drinks – BBC News

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Some children have found a devious method to get out of school – using cola to create false positive Covid tests. How does it work?

Children are always going to find cunning ways to bunk off school, and the latest trick is to fake a positive Covid-19 lateral flow test (LFT) using soft drinks. [Videos of the trick have been circulating on TikTok since December and a school in Liverpool, UK, recently wrote to parents to warn them about it.] So how are fruit juices, cola and devious kids fooling the tests, and is there a way to tell a fake positive result from a real one? I’ve tried to find out.

First, I thought it best to check the claims, so I cracked open bottles of cola and orange juice, then deposited a few drops directly onto LFTs. Sure enough, a few minutes later, two lines appeared on each test, supposedly indicating the presence of the virus that causes Covid-19.

It’s worth understanding how the tests work. If you open up an LFT device, you’ll find a strip of paper-like material, called nitrocellulose, and a small red pad, hidden under the plastic casing below the T-line. Absorbed on the red pad are antibodies that bind to the Covid-19 virus. They are also attached to gold nanoparticles (tiny particles of gold actually appear red), which allow us to see where the antibodies are on the device. When you do a test, you mix your sample with a liquid buffer solution, ensuring the sample stays at an optimum pH, before dripping it on the strip.

The fluid wicks up the nitrocellulose strip and picks up the gold and antibodies. The latter also bind to the virus, if present. Further up the strip, next to the T (for test), are more antibodies that bind the virus. But these antibodies are not free to move – they are stuck to the nitrocellulose. As the red smear of gold-labelled antibodies pass this second set of antibodies, these also grab hold of the virus. The virus is then bound to both sets of antibodies – leaving everything, including the gold, immobilised on a line next to the T on the device, indicating a positive test.

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Gold antibodies that haven’t bound to the virus carry on up the strip where they meet a third set of antibodies, not designed to pick up Covid-19, stuck at the C (for control) line. These trap the remaining gold particles, without having to do so via the virus. This final line is used to indicate the test has worked.

The acidity of many soft drinks and fruit juices can lead to false positives in the Covid-19 lateral flow test but still be negative with a PCR test (Credit: Mark Lorch)

So, how can a soft drink cause the appearance of a red T line? One possibility is that the drinks contain something that the antibodies recognise and bind to, just as they do to the virus. But this is rather unlikely. The reason antibodies are used in tests like these is that they are incredibly fussy about what they bind to. There’s all sorts of stuff in the snot and saliva collected by the swabs you take from the nose and mouth, and the antibodies totally ignore this mess of protein, other viruses and remains of your breakfast. So they aren’t going to react to the ingredients of a soft drink.

A much more likely explanation is that something in the drinks is affecting the function of the antibodies. A range of fluids, from fruit juice to cola, have been used to fool the tests, but they all have one thing in common – they are highly acidic. The citric acid in orange juice, phosphoric acid in cola and malic acid in apple juice give these beverages a pH between 2.5 and 4. These are pretty harsh conditions for antibodies, which have evolved to work largely within the bloodstream, with its almost neutral pH of about 7.4.

Maintaining an ideal pH for the antibodies is key to the correct function of the test, and that’s the job of the liquid buffer solution that you mix your sample with, provided with the test. The critical role of the buffer is highlighted by the fact that if you mix cola with the buffer – as shown in this debunking of an Australian politician’s claim that mass testing is worthless – then the LFTs behave exactly as you’d expect: negative for Covid-19.

So without the buffer, the antibodies in the test are fully exposed to the acidic pH of the beverages. And this has a dramatic effect on their structure and function. Antibodies are proteins, which are comprised of amino acid building blocks, attached together to form long, linear chains. These chains fold up into very specific structures. Even a small change to the chains can dramatically impact a protein’s function. These structures are maintained by a network of many thousands of interactions between the various parts of the protein. For example, negatively charged parts of a protein will be attracted to positively charged areas.

Many schools in the UK have used regular lateral flow testing to check whether pupils might be carrying the Covid-19 virus (Credit: Oli Scarff/AFP/Getty Images)

Many schools in the UK have used regular lateral flow testing to check whether pupils might be carrying the Covid-19 virus (Credit: Oli Scarff/AFP/Getty Images)

But in acidic conditions, the protein becomes increasingly positively charged. As a result, many of the interactions that hold the protein together are disrupted, the delicate structure of the protein is affected and it no longer functions correctly. In this case, the antibodies’ sensitivity to the virus is lost.

Given this, you might expect that the acidic drinks would result in completely blank tests. But denatured proteins are sticky beasts. All of those perfectly evolved interactions that would normally hold the protein together are now orphaned and looking for something to bind to. A likely explanation is that the immobilised antibodies at the T-line stick directly to the gold particles as they pass by, producing the notorious cola-induced false positive result.

Is there then a way to spot a fake positive test? The antibodies (like most proteins) are capable of refolding and regaining their function when they are returned to more favourable conditions. So I tried washing a test that had been dripped with cola with buffer solution, and sure enough the immobilised antibodies at the T-line regained normal function and released the gold particles, revealing the true negative result on the test.

Children, I applaud your ingenuity, but now that I’ve found a way to uncover your trickery I suggest you use your cunning to devise a set of experiments and test my hypothesis. Then we can publish your results in a peer-reviewed journal.

* Mark Lorch is a professor of chemistry and science communication at the University of Hull, UK.

This article originally appeared on The Conversation, and is republished under a Creative Commons licence. 

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Facial Recognition—Now for Seals – Hakai Magazine

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Have you ever looked at a seal and thought, Is that the same seal I saw yesterday? Well, there could soon be an app for that based on new seal facial recognition technology. Known as SealNet, this seal face-finding system was developed by a team of undergraduate students from Colgate University in New York.

Taking inspiration from other technology adapted for recognizing primates and bears, Krista Ingram, a biologist at Colgate University, led the students in developing software that uses deep learning and a convolutional neural network to tell one seal face from another. SealNet is tailored to identify the harbor seal, a species with a penchant for posing on coasts in haulouts.

The team had to train their software to identify seal faces. “I give it a photograph, it finds the face, [and] clips it to a standard size,” says Ingram. But then she and her students would manually identify the nose, the mouth, and the center of the eyes.

For the project, team members snapped more than 2,000 pictures of seals around Casco Bay, Maine, during a two-year period. They tested the software using 406 different seals and found that SealNet could correctly identify the seals’ faces 85 percent of the time. The team has since expanded its database to include around 1,500 seal faces. As the number of seals logged in the database goes up, so too should the accuracy of the identification, Ingram says.

The developers of SealNet trained a neural network to tell harbor seals apart using photos of 406 different seals. Photo courtesy of Birenbaum et al.

As with all tech, however, SealNet is not infallible. The software saw seal faces in other body parts, vegetation, and even rocks. In one case, Ingram and her students did a double take at the uncanny resemblance between a rock and a seal face. “[The rock] did look like a seal face,” Ingram says. “The darker parts were about the same distance as the eyes … so you can understand why the software found a face.” Consequently, she says it’s always best to manually check that seal faces identified by the software belong to a real seal.

Like a weary seal hauling itself onto a beach for an involuntary photo shoot, the question of why this is all necessary raises itself. Ingram believes SealNet could be a useful, noninvasive tool for researchers.

Of the world’s pinnipeds—a group that includes seals, walruses, and sea lions—harbor seals are considered the most widely dispersed. Yet knowledge gaps do exist. Other techniques to track seals, such as tagging and aerial monitoring, have their limitations and can be highly invasive or expensive.

Ingram points to site fidelity as an aspect of seal behavior that SealNet could shed more light on. The team’s trials indicated that some harbor seals return to the same haulout sites year after year. Other seals, however, such as two animals the team nicknamed Clove and Petal, appeared at two different sites together. Increasing scientists’ understanding of how seals move around could strengthen arguments for protecting specific areas, says Anders Galatius, an ecologist at Aarhus University in Denmark who was not involved in the project.

Galatius, who is responsible for monitoring Denmark’s seal populations, says the software “shows a lot of promise.” If the identification rates are improved, it could be paired with another photo identification method that identifies seals by distinctive markings on their pelage, he says.

In the future, after further testing, Ingram hopes to develop an app based on SealNet. The app, she says, could possibly allow citizen scientists to contribute to logging seal faces. The program could also be adapted for other pinnipeds and possibly even for cetaceans.

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NASA launches nanosatellite in preparation for lunar 'Gateway' station – Yahoo News Canada

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The rocket carrying the Capstone satellite lifts off. (NASA)

Nasa has launched a tiny CubeSat this week to test and orbit which will soon be used by Gateway, a lunar space station.

It’s all part of the space agency’s plan to put a woman on the moon by 2025.

The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (Capstone) mission launched from New Zealand on Tuesday.

Jim Reuter, associate administrator for the Space Technology Mission Directorate, said: “Capstone is an example of how working with commercial partners is key for Nasa’s ambitious plans to explore the moon and beyond.

“We’re thrilled with a successful start to the mission and looking forward to what Capstone will do once it arrives at the Moon.”

Read more: Astronomers find closest black hole to Earth

The satellite is currently in low-Earth orbit, and it will take the spacecraft about four months to reach its targeted lunar orbit.

Capstone is attached to Rocket Lab’s Lunar Photon, an interplanetary third stage that will send it on its way to deep space.

Over the next six days, Photon’s engine will periodically ignite to accelerate it beyond low-Earth orbit, where Photon will release the CubeSat on a trajectory to the moon.

Capstone will then use its own propulsion and the sun’s gravity to navigate the rest of the way to the Moon.

The gravity-driven track will dramatically reduce the amount of fuel the CubeSat needs to get to the Moon.

Read more: There might once have been life on the moon

Bradley Cheetham, principal investigator for CAPSTONE and chief executive officer of Advanced Space, “Our team is now preparing for separation and initial acquisition for the spacecraft in six days.

“We have already learned a tremendous amount getting to this point, and we are passionate about the importance of returning humans to the Moon, this time to stay!”

At the moon, Capstone will enter an elongated orbit called a near rectilinear halo orbit, or NRHO.

Once in the NRHO, Capstone will fly within 1,000 miles of the moon’s north pole on its near pass and 43,500 miles from the south pole at its farthest.

It will repeat the cycle every six-and-a-half days and maintain this orbit for at least six months to study dynamics.

“Capstone is a pathfinder in many ways, and it will demonstrate several technology capabilities during its mission timeframe while navigating a never-before-flown orbit around the Moon,” said Elwood Agasid, project manager for Capstone at Nasa’s Ames Research Center in California’s Silicon Valley.

“Capstone is laying a foundation for Artemis, Gateway, and commercial support for future lunar operations.”

Nasa estimates the cost of the whole Artemis mission at $28bn.

It would be the first time people have walked on the moon since the last Apollo moon mission in 1972.

Just 12 people have walked on the moon – all men.

Nasa flew six manned missions to the surface of the moon, beginning with Neil Armstrong and Buzz Aldrin in July 1969, up to Gene Cernan and Jack Schmitt in December 1972.

The mission will use Nasa’s powerful new rocket, the Space Launch System (SLS), and the Orion spacecraft.

Watch: NASA launch paves way for moon orbit station

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The year’s biggest and brightest supermoon will appear in July & here’s when you’ll … – Curiocity

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Summer is here and with it? Sunshine – and some serious moonshine (of the visible variety, of course). This upcoming month, look up in anticipation of the biggest and brightest event of the year, the July Buck supermoon – which will hover over North America on July 13th.

Appearing 7% larger and lower in the sky, this particular event will be one well worth keeping an eye on when it rises above the horizon.

This will be the closest we’ll get to our celestial neighbour in 2022 (357,418 km) and while North America won’t get to see it when it reaches peak illumination at 2:38 pm ETC., it’ll still look pretty dang impressive after the sunsets.

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Not sure when the moon rises in your area? Here’s the earliest that you’ll be able to see the moon in various cities across the continent according to the Farmer’s Almanac.

  • Seattle, Washington  – 9:50 pm PDT
  • Vancouver, British Columbia – 10:02 pm PDT
  • Calgary, Alberta – 10:35 pm MST
  • Edmonton, Alberta – 10:49 pm MST
  • Toronto, Ontario – 9:34 pm MST
  • Montreal, Quebec – 9:18 pm MST

Until then, cross your fingers for a clear sky, friends! It’s going to be incredible.

Happy viewing.

JULY BUCK SUPERMOON 

When: Wednesday, July 13th

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