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Comment by Dr. Krishna Kumari Challa on March 28, 2021 at 10:00am

Scientists Discover Deep-Sea Microbes That Are Invisible to Our Immune System

Bacteria collected from more than a mile below the surface of the Pacific Ocean may have just blown one of immunology's longest-held assumptions clean out of the water.

The bacteria are so alien to humans that our immune cells do not even register that they exist, making them completely invisible to our immune systems.

This totally contradicts one of the classic tenets of immunology – that the human immune system evolved to be able to sense every single microbe so it could catch the infectious ones.

"The idea was that the immune system is a generalist, it doesn't care if something was a threat or not, it just got rid of it. But no one had really pressure tested that assumption until now.

To test this, the researchers had to find bacteria that were unlikely to have ever had previous contact with mammalian immune systems. They chose a spot deep in the central Pacific Ocean, in the Phoenix Islands Protected Area in Kiribati, 1,650 miles (2,655 kilometers) southwest of Hawaii.

"It's not just the deep ocean, but the most deep, ancient, remote, and protected part of the ocean. It's 4,000 meters (13,100 feet) deep; there are no resident mammals; and it's on the equatorial space where there wouldn't even be any whales for there to be any whale falls. 

Once there, researchers used a remote submarine to collect marine bacteria from samples of water, sponge, sea star, and sediment, before growing them into 117 culturable species.

After identifying the features of their bacteria, the researchers introduced 50 of the strains to mouse and human immune cells. To their surprise, they found that 80 percent of the microbes, mostly belonging to the genus Moritella, escaped detection. The receptors on the mammalian bone marrow immune cells used in the study were incapable of seeing them.

To try to narrow down which features of the marine bacteria made them invisible to our immune receptors, the team also exposed the mouse and human cells to just one specific part of the bacterial cell wall, called the lipopolysaccharide (LPS). Mammalian immune systems are known to use this outermost part of the bacterial cell wall to recognize so-called gram-negative bacteria and put up a fight.

The researchers found that the mammal cells' receptors were blind to the LPS on its own, too.

"The LPS molecules looked similar to what you'd find in bacteria on land, but many of them were completely silent," Kagan said. "This is because the lipid chains on the LPS turned out to be much longer than the ones we're used to on land, but we still don't know why that means they can go undetected."

Despite their spooky ability to evade detection, the researchers said that deep-sea bacteria don't pose any risk of infecting people. 

Firstly, they haven't evolved to evade mammalian immune systems, so if there was any pathogenicity it would be accidental. The second reason it's highly unlikely is that the temperatures, pressures, and the chemical environments inside our bodies are so different to what you'd find at the bottom of the ocean. These bacteria aren't happy for more than a few minutes outside of their normal habitat.

https://immunology.sciencemag.org/content/6/57/eabe0531

https://www.sciencealert.com/scientists-discover-deep-sea-microbes-...

Comment by Dr. Krishna Kumari Challa on March 28, 2021 at 9:53am

Corals may need their predators' poop

How Scientists Are Restoring The Great Barrier Reef

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:58pm

First Report of Horizontal Gene Transfer Between Plant and Animal

Whiteflies overcome a toxin in plants they eat through the use of the plant’s own genetic protection, likely ferried from plant to insect millions of years ago by a virus.

In the first known example of horizontal gene transfer between a plant and an animal, a common pest known as the whitefly (Bemisia tabaci) acquired a gene from the one of the various plants it feeds on, researchers reported today (March 25) in Cell. The gene, BtPMaT1, protects the insects from phenolic glycosides, toxins that many plants produce to defend themselves against such pests, thus allowing the whiteflies to feast.

J. Xia et al., “Whitefly hijacks a plant detoxification gene that neutralizes plant toxins,” Cell, doi:10.1016/j.cell.2021.02.014, 2021.

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:49pm

It's snowing plastic

The snow may be melting, but it is leaving pollution behind in the form of micro- and nano-plastics according to a McGill study that was recently published in Environmental Pollution. The pollution is largely due to the relatively soluble plastics found in antifreeze products (polyethylene glycols) that can become airborne and picked up by the snow.

The researchers used a new technique that they have developed to analyze snow samples collected in April 2019 in Montreal for both micro- and nano-sized particles of various plastics. The McGill technique is orders of magnitude more sensitive than any of the other current methods used for tracing plastic in the environment. It allows scientists to detect ultra-trace quantities of many of the most common soluble and insoluble plastics in snow, water, rainfall, and even in soil samples once they have been separated – down to the level of a picogram (or one trillionth of a gram). It is based on using nano-structured mass spectrometry and, unlike other techniques currently in use, the new technique is both recyclable and based on sustainable practices.

https://researchnews.cc/news/5835/It-s-snowing-plastic#.YF7xN68zbIU

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:47pm

Testing the Best Bomb Detectors

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:45pm

Excess blood sugar promotes clogging of arteries: study

Excess sugar in the blood, the central feature of diabetes, can react with immune proteins to cause myriad changes in the immune system, including inflammatory changes that promote atherosclerosis, according to a new study from scientists at Weill Cornell Medicine and University of Massachusetts Medical School. The study, published March 15 in the journal Immunity, advances the field of diabetes research by revealing molecular pathways through which the disorder may cause other serious health problems for patients. In principle, these newly revealed pathways could be targeted with future diabetes drugs.

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:41pm

The physics of the stuck Suez ship

High winds combined with ship–bank interaction effects might have sent the huge container ship Ever Given into a spin in the shallow waters of the Suez Canal, suggests hydrodynamicist Evert Lataire. The boat has been wedged fast in the essential shipping route since Tuesday. Bank effects occur in restricted navigation areas, where water displaced by a ship has nowhere to go. As a ship passes close to the side of a shallow channel, the water in the gap must speed up, causing the stern to pull into the bank and the bow to be pushed away. In the case of the Ever Given, the effect could have caused the ship to veer into the opposite bank, as shown in this VesselFinder video.

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:36pm

Octopuses, like humans, sleep in two stages

When researchers filmed captive Octopus insularis octopuses sleeping in their tanks, they recorded alternating phases of “quiet sleep”, in which the creatures were pale and still, followed by short spurts of “active sleep”, in which their skin turned darker and stiffened, they moved their eyes, and muscular twitches contracted their suckers. In mammals, birds and perhaps in reptiles, this two-stage sleep pattern is thought to help consolidate memories and clear waste from the brain. Because our last common ancestor with octopuses lived more than 500 million years ago, it seems that the molluscs evolved this sleeping pattern separately, so its function remains unclear.

https://www.sciencemag.org/news/2021/03/octopuses-humans-sleep-two-...

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:29pm

Molecule attacks coronavirus in a novel way

Scientists at the University of Bonn and the caesar research center have isolated a molecule that might open new avenues in the fight against SARS coronavirus 2. The active ingredient binds to the spike protein that the virus uses to dock to the cells it infects. This prevents them from entering the respective cell, at least in the case of model viruses. It appears to do this by using a different mechanism than previously known inhibitors. The researchers therefore suspect that it may also help against viral mutations. The study will be published in the journal Angewandte Chemie but is already available online.

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Differences in snake venom composition raise questions about treatment

Snakebite kills around 58,000 Indians annually, and a majority of snakebites that lead to death or disability are attributed to the 'big four' of Indian snakes—the Russell's viper (Daboia russelii), one of the deadliest snake species in the world, the spectacled cobra (Naja naja), the common krait (Bungarus caeruleus) and the saw-scaled viper (Echis carinatus). Commercial antivenom treatment for snakebite does not always prove effective, and despite the severity of the problem in India, few efforts have been made to understand why this is so.

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:22pm

Cooling homes without warming the planet

As global temperatures are increasing, demand for air conditioners is expected to triple by 2050. The surge will multiply what is already a major source of greenhouse gas emissions: Air conditioning is currently responsible for almost 20 percent of electricity use in buildings around the world.

Now the startup Transaera is working to curb those energy demands with a more efficient air conditioner that uses safer refrigerants to cool homes. The company believes its machine could have one-fifth the impact on the climate when compared to traditional ACs. 

The thing about air conditioning is the basic technology hasn't changed much since it was invented 100 years ago. 

That will change rapidly if Transaera's small team is successful. The company is currently a finalist in a global competition to redesign the air conditioner. The winner of the competition, named the Global Cooling Prize, will get $1 million to commercialize their machines.

At the heart of Transaera's design is a class of highly porous materials called metal organic frameworks, or MOFs, that passively pull moisture from the air as the machine works. MOFs have a lot of potential applications, but the thing that's held them back is unit economics and the inability to make them in a cost-effective way at scale. What Transaera aims to do is be the first to commercialize MOFs at scale and lead the breakthrough that brings MOFs into the public domain.

Most people think air conditioners only cool the air in a space, but they also dry the air they're cooling. Traditional machines use something called an evaporator, a cold coil to pull water out of the air through condensation. The cold coil must be made much colder than the desired temperature in the room in order to collect moisture. Pulling moisture out of the air takes up about half of the electricity used by traditional air conditioners.

Transaera's MOFs passively collect moisture as air enters the system. The machine's waste heat is then used to dry the MOF material for continuous reuse.

https://news.mit.edu/2021/transaera-air-conditioner-0326

https://phys.org/news/2021-03-cooling-homes-planet.html?utm_source=...

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