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Three scientists give their best advice on how to protect yourself from COVID-19 – CBS News

Scientists flag airborne coronavirus spread


Scientists flag airborne coronavirus spread

03:39

Over the past several months, there has been controversy over the way SARS-CoV-2, the virus that causes COVID-19, travels from an infected person to others. While official guidance has often been unclear, some aerosol scientists and public health experts have maintained that the spread of the virus in aerosols traveling through the air at distances both less than and greater than 6 feet has been playing a more significant role than appreciated. 

In July, 239 scientists from 32 countries urged the World Health Organization (WHO) to acknowledge the possible role of airborne transmission in the spread of SARS-CoV-2. 

Three days later, WHO did so, stating that under certain conditions, “short-range aerosol transmission, particularly in specific indoor locations, such as crowded and inadequately ventilated spaces over a prolonged period of time with infected persons cannot be ruled out.”

Many scientists rejoiced on social media when the CDC appeared to agree, acknowledging for the first time in a September 18 website update that aerosols play a meaningful role in the spread of the virus. The update stated that COVID-19 can spread “through respiratory droplets or small particles, such as those in aerosols, produced when an infected person coughs, sneezes, sings, talks or breathes. These particles can be inhaled into the nose, mouth, airways and lungs and cause infection. This is thought to be the main way the virus spreads.” 

However, controversy arose again when, three days later, the CDC took down that guidance, saying it had been posted by mistake, without proper review. 

Right now, the CDC website does not acknowledge that aerosols typically spread SARS-CoV-2 beyond 6 feet, instead saying: “COVID-19 spreads mainly among people who are in close contact (within about 6 feet) for a prolonged period. Spread happens when an infected person coughs, sneezes or talks, and droplets from their mouth or nose are launched into the air and land in the mouths or noses of people nearby. The droplets can also be inhaled into the lungs.”

The site says that respiratory droplets can land on various surfaces, and people can become infected from touching those surfaces and then touching their eyes, nose or mouth. It goes on to say, “Current data do not support long range aerosol transmission of SARS-CoV-2, such as seen with measles or tuberculosis. Short-range inhalation of aerosols is a possibility for COVID-19, as with many respiratory pathogens. However, this cannot easily be distinguished from ‘droplet’ transmission based on epidemiologic patterns. Short-range transmission is a possibility particularly in crowded medical wards and inadequately ventilated spaces.”


Professor Kimberly Prather, PhD, Distinguished Chair in Atmospheric Chemistry at UC San Diego by
Jonathan LaPook on
YouTube

Confusion has surrounded the use of words like “aerosols” and “droplets” because they have not been consistently defined. And the word “airborne” takes on special meaning for infectious disease experts and public health officials because of the question of whether infection can be readily spread by “airborne transmission.” If SARS-CoV-2 is readily spread by airborne transmission, then more stringent infection control measures would need to be adopted, as is done with airborne diseases such as measles and tuberculosis. But the CDC has told CBS News chief medical correspondent Dr. Jonathan LaPook that even if airborne spread is playing a role with SARS-CoV-2, the role does not appear to be nearly as important as with airborne infections like measles and tuberculosis.

All this may sound like wonky scientific discussion that is deep in the weeds — and it is — but it has big implications as people try to figure out how to stay safe during the pandemic. Some pieces of advice are intuitively obvious: wear a mask, wash your hands, avoid crowds, keep your distance from others, outdoors is safer than indoors. But what about that “6 foot” rule for maintaining social distance? If the virus can travel indoors for distances greater than 6 feet, isn’t it logical to wear a mask indoors whenever you are with people who are not part of your “pod” or “bubble?” 

Understanding the basic science behind how SARS-CoV-2 travels through the air should help give us strategies for staying safe. Unfortunately, there are still many open questions. For example, even if aerosols produced by an infected person can float across a room, and even if the aerosols contain some viable virus, how do we know how significant a role that possible mode of transmission is playing in the pandemic? 

As we await answers from ongoing research, Dr. LaPook turned to three leading scientists to try to clear the air. Acknowledging that the science is still not set in stone, they have generously agreed to give us their best advice on how to think about protecting ourselves, based on their current understanding of the way SARS-CoV-2 can spread. Below, atmospheric chemist Kimberly Prather, airborne virus expert Linsey Marr and environmental health professor Donald Milton discuss the best precautions you can take to reduce your risk of infection.

Clearing the air

In contrast to early thinking about the importance of transmission by contact with large respiratory droplets, it turns out that a major way people become infected is by breathing in the virus. This is most common when someone stands within 6 feet of a person who has COVID-19 (with or without symptoms), but it can also happen from more than 6 feet away.

Viruses in small, airborne particles called aerosols can infect people at both close and long range. Aerosols can be thought of as cigarette smoke. While they are most concentrated close to someone who has the infection, they can travel farther than 6 feet, linger, build up in the air and remain infectious for hours. As a consequence, to lessen the chance of inhaling this virus, it is vital to take all of the following steps:

Indoors:

  • Practice physical distancing — the farther the better.

  • Wear a face mask when you are with others, even when you can maintain physical distancing. Face masks not only lessen the amount of virus coming from people who have the infection, but also lessen the chance of you inhaling the virus.

  • Improve ventilation by opening windows. Learn how to clean the air effectively with methods such as filtration.

Outdoors:

  • Wear a face mask if you cannot physically distance by at least 6 feet or, ideally, more. 

  • Whenever possible, move group activities outside. 

Whether you are indoors or outdoors, remember that your risk increases with the duration of your exposure to others.

With the question of transmission, it’s not just the public that has been confused. There’s also been confusion among scientists, medical professionals and public health officials, in part because they have often used the words “droplets” and “aerosols” differently. To address the confusion, participants in an August workshop on airborne transmission of SARS-CoV-2 at the National Academies of Sciences, Engineering, and Medicine unanimously agreed on these definitions for respiratory droplets and aerosols:

  • Droplets are larger than 100 microns and fall to the ground within 6 feet, traveling like tiny cannonballs.

  • Aerosols are smaller than 100 microns, are highly concentrated close to a person, can travel farther than 6 feet and can linger and build up in the air, especially in rooms with poor ventilation. 

All respiratory activities, including breathing, talking and singing, produce far more aerosols than droplets. A person is far more likely to inhale aerosols than to be sprayed by a droplet, even at short range. The exact percentage of transmission by droplets versus aerosols is still to be determined. But we know from epidemiologic and other data, especially superspreading events, that infection does occur through inhalation of aerosols. 

In short, how are we getting infected by SARS-CoV-2? The answer is: In the air. Once we acknowledge this, we can use tools we already have to help end this pandemic.


Kimberly A. Prather, PhD, Distinguished Chair in Atmospheric Chemistry, Scripps Institution of Oceanography, UC San Diego.

Linsey C Marr, PhD, Charles P. Lunsford Professor of Civil and Environmental Engineering, Virginia Tech.

Donald K Milton, MD, DrPH, Professor of Environment Health at The University of Maryland School of Public Health.



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COVID scientists

Covid Scientists Find a Turning Point in Life-Threatening Cases – Bloomberg QuickTake: Now


Covid Scientists Find a Turning Point in Life-Threatening Cases – YouTube

























































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scientists shine

Scientists shine light on tiny crystals behind unexpected violent eruptions – Phys.org

Bristol scientists shine light on tiny crystals behind unexpected violent eruptions
Nanolite ‘snow’ surrounding an iron oxide microlite ‘Christmas tree’. Even these small 50 nm spheres are actually made up of even smaller nanolites aggregated into clumps. Christmas has come early this year for these researchers. Credit: Brooker/Griffiths/Heard/Cherns

In a new study of volcanic processes, Bristol scientists have demonstrated the role nanolites play in the creation of violent eruptions at otherwise ‘calm’ and predictable volcanoes.

The study, published in Science Advances, describes how nano-sized crystals (nanolites), 10,000 times smaller than the width of a human hair, can have a significant impact of the viscosity of erupting , resulting in previously unexplained and .

“This discovery provides an eloquent explanation for violent eruptions at volcanos that are generally well behaved but occasionally present us with a deadly surprise, such as the 122 BC of Mount Etna,” said Dr. Danilo Di Genova from the University of Bristol’s School of Earth Sciences.

“Volcanoes with low silica magma compositions have very low viscosity, which usually allows the gas to gently escape. However, we’ve shown that nanolites can increase the viscosity for a limited time, which would trap gas in the sticky liquid, leading to a sudden switch in behavior that was previously difficult to explain.”

Dr. Richard Brooker also from Earth Sciences, said: “We demonstrated the surprising effect of nanolites on magma viscosity, and thereby , using cutting-edge nano-imaging and Raman spectroscopy to hunt for evidence of these almost invisible particles in ash erupted during very violent eruptions.”

Bristol scientists shine light on tiny crystals behind unexpected violent eruptions
The erupted Etna rock is melted in a wire furnace on the synchrotron beamline at Diamond Light Source. Credit: Richard Brooker

“The next stage was to re-melt these rocks in the laboratory and recreate the correct cooling rate to produce nanolites in the molten magma. Using the scattering of extremely bright synchrotron source radiation (10 billion times brighter than the sun) we were able to document nanolite growth.”

“We then produced a nanolite-bearing basaltic foam (pumice) under laboratory conditions, also demonstrating how these nanolites can be produced by undercooling as volatiles are exsolved from magma, lowering the liquidus.”

Professor Heidy Mader added: “By conducting new experiments on analog synthetic materials, at low shear rates relative to volcanic systems, we were able to demonstrate the possibility of extreme viscosities for nanolite-bearing magma, extending our understanding of the unusual (non-Newtonian) behavior of nanofluids, which have remained enigmatic since the term was coined 25 years ago.”

Bristol scientists shine light on tiny crystals behind unexpected violent eruptions
Usual gentle effusive eruption typical of Mt Etna (Italy). Credit: Boccia Pasquale from Pixabay

The next stage for this research is to model this dangerous, unpredictable volcanic behavior in actual volcanic situations. This is the focus of a Natural Environment Research Council (UK) and National Science Foundation (US) grant ‘Quantifying Disequilibrium Processes in Basaltic Volcanism’ awarded to Bristol and a consortium of colleagues in Manchester, Durham, Cambridge and Arizona State University.



More information:
“In situ observation of nanolite growth in volcanic melt: A driving force for explosive eruptions” Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abb0413

Citation:
Scientists shine light on tiny crystals behind unexpected violent eruptions (2020, September 23)
retrieved 23 September 2020
from https://phys.org/news/2020-09-scientists-tiny-crystals-unexpected-violent.html

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discover scientists

Scientists Discover Sugar Molecules in SARS-CoV-2 Coronavirus Spike Protein Play Active Role in Infection – SciTechDaily

SARS-CoV-2 Spike Protein Glycans

In this illustration, glycans (dark blue) coat the SARS-CoV-2 spike protein (light blue), which is anchored in the viral envelope (colorful bilayer on bottom). Credit: Adapted from ACS Central Science 2020, DOI: 10.1021/acscentsci.0c01056

As the COVID-19 pandemic rages on, researchers are working overtime to develop vaccines and therapies to thwart SARS-CoV-2, the virus responsible for the disease Many efforts focus on the coronavirus spike protein, which binds the angiotensin-converting enzyme 2 (ACE2) on human cells to allow viral entry. Now, researchers reporting in ACS Central Science have uncovered an active role for glycans — sugar molecules that can decorate proteins — in this process, suggesting targets for vaccines and therapies.

Before the SARS-CoV-2 spike protein can interact with ACE2 on a human cell, it changes shape to expose its receptor binding domain (RBD), the part of the protein that interacts with ACE2. Like many viral proteins, the SARS-CoV-2 spike protein has a thick coat of glycans on its surface. These glycans, which are attached at specific sites, help shield the viral proteins from the host immune system. Rommie Amaro and colleagues at University of California San Diego, Maynooth University (Ireland) and the University of Texas at Austin wondered whether certain glycans in the SARS-CoV-2 spike protein might also be active players in the process leading to infection.

To find out, the researchers used structural and glycomic data to build molecular dynamics simulations of the SARS-CoV-2 spike protein embedded in the viral membrane. The computer models, which presented a detailed snapshot of every atom in the spike glycoprotein, revealed that N-glycans linked to the spike protein at certain sites (N165 and N234) helped stabilize the shape change that exposes the RBD, which could help promote infection. The simulations also identified regions of the spike protein that weren’t coated by glycans and thus could be vulnerable to antibodies, especially after the shape change. In laboratory experiments using biolayer interferometry, the team showed that mutating the spike protein so that it no longer had glycans at N165 and N234 reduced binding to ACE2. These results lay the foundation for new strategies to fight the pandemic threat, the researchers say.

Reference: 23 September 2020, ACS Central Science.

DOI: 10.1021/acscentsci.0c01056

The authors acknowledge funding from the National Institutes of Health, the National Science Foundation, the Research Corporation for Science Advancement, UC San Diego Moores Cancer Center, the Irish Research Council, and the Visible Molecular Cell Consortium.

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Climate scientists

Scientists: Climate change bacteria killed 300 African elephants – Quartz Africa

Veterinary scientists have confirmed that a bacterial toxin other scientists say is thriving more because of warming temperatures in water bodies as a result of climate change is the cause of massive elephant deaths in Botswana this year.

The death toll of elephants in the southern Africa country has subsequently risen to 330, with Monday’s announcement by its Department of National Parks and Wildlife confirming the elephants drank water contaminated by cyanobacteria. The research findings, building on tests conducted in laboratories in Zimbabwe, South Africa, the US, and Canada, represents a ground-breaking and until now elusive scientific explanation that could also provide answers to the yet to be explained deaths of more elephants in neighboring Zimbabwe.

Botswana first discovered carcasses of elephants along the wildlife rich Okavango Delta in May and June but was authorities were uncertain as to the cause of the mass deaths, leaving scientists and conservationists puzzled. Only last month, Zimbabwe’s Parks and Wildlife Authority said more than 20 elephants had also died in its massive Hwange National Park although this time there was a clue that the deaths could have been caused by bacterial infection after ruling out anthrax and poisoning by poachers.

REUTERS/Handout

Dead elephants in Okavango Delta, Botswana May-June, 2020.

Tests detected “cyanobacterial neurotoxins” in the waters of the Okavango Delta within the areas where the elephants were found dead. Climate scientists have been warning about the impact of heating up temperatures on earth including creating environments conducive for the presence of cyanobacteria which favors warmer water temperatures.

Temperatures have been rising in sub-Saharan Africa, with countries in the Southern African region suffering prolonged droughts in recent years. Botswana’s research findings into the deaths of 300 of its elephants could be useful for scientists and conservationists as they re-think their approach and strategies to wildlife conservation and environmental management.

Botswana holds nearly a third of Africa’s elephant population while Zimbabwe’s elephant population, decimated by poachers, has been described as unsustainable as it outstrips available habitat, further risking any conservation interventions.

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Discovered scientists

Scientists discovered phosphine gas, a sign of life, on Venus. What might life look like there? – Vox.com

The search for life in our solar system got a lot more exciting this week. On Monday, a team of scientists announced its members had detected phosphine gas in the caustic, hot atmosphere of Venus. So what? The gas — which you’d recognize by its fishy odor — is thought to be a byproduct of life.

“We did exhaustively search through all known chemistry … and we didn’t find anything that could produce more than the tiniest amount of phosphine in Venus’s atmosphere,” says MIT planetary scientist Sara Seager, who was one of the co-authors on the discovery published in Nature Astronomy, says. That leaves us two possibilities: The gas was created by life or by some chemical interaction scientists don’t yet know about.

Seager is one of the leading dreamers and thinkers in astronomy, looking for life beyond our planet. She studies planets orbiting stars many light-years away and thinks about how to detect life on them and others closer to home, like Venus.

She’s also thinking creatively about the microscopic life forms that could potentially survive there. This summer, before the phosphine announcement, she and her co-authors published a speculative, hypothetical sketch of what life on Venus could look like. The vision is beautiful: a living rain of microbes floating, cyclically, in the clouds, blooming and desiccating continually for millions of years.

I wanted to hear more about this vision of life in a world so very different from our own, so I called her up.

This conversation has been edited for length and clarity.

Evidence for life on the planet next door

Brian Resnick

To start off: What’s the gist of the discovery that you and the team announced this week?

Sara Seager

We aren’t claiming we found signs of life. We are claiming we have a robust detection of the gas phosphine in the atmosphere.

[After searching] all the known chemistry — volcanoes, photochemistry, lightning — we didn’t find anything that could produce more than the tiniest amount of phosphine in Venus’s atmosphere. So we’re left with two possibilities. One is that there is some kind of unknown chemistry, which seems unlikely. And the other possibility is that there’s some kind of life, which seems even more unlikely. So that’s where we’re at. It took a long time to accept it.

Brian Resnick

Okay, so it’s very unlikely. Has Venus historically been thought of as a place life might exist in the solar system?

Sara Seager

It’s been fringe pretty much the whole time that it’s been a topic. Carl Sagan first proposed there could be life in [Venus’s] clouds. There is a small group [of scientists] that writes about this topic. A lot of people love it. It’s like a closeted love because a lot of people are enthusiastic about it, but they either didn’t want to say so or they never had a reason to say so.

Brian Resnick

What do they love about it?

Sara Seager

I think it’s just the intrigue that there could be life so close to home.

[Venus is closer to Earth than Mars. It’s also the second-brightest object in our night sky, other than the moon.]

Why life would have to exist in Venus’s clouds, not on the surface

An artist’s concept of active volcanoes on Venus.
NASA/JPL-Caltech/Peter Rubin

Brian Resnick

As I understand it, if life exists on Venus, it wouldn’t be on the surface of the planet, but in its sulfuric acid clouds?

Sara Seager

It’s always been the theory because the surface is too hot for complex molecules.

Brian Resnick

What is too hot? What happens there?

Sara Seager

Molecules break apart. If you took a protein or an amino acid, or anything, and put it in high temperature, it would come apart into smaller fragments and atoms.

Brian Resnick

Why, then, is the atmosphere a better place to look for life?

Sara Seager

It has the things that astrobiologists think life needs. It needs a liquid of some kind. And there is liquid in the atmosphere, although it is liquid sulfuric acid.

Life needs an energy source. So there’s definitely the sun, at least as an energy source. Life needs the right temperature. In the atmosphere, there is the right temperature. And life needs a changing environment to promote Darwinian evolution. So if you want to break it down like that, that’s why. To simplify, it’s mostly the temperature argument. Temperature and liquid.

Brian Resnick

Do we know of any life form on Earth that can exist in liquid sulfuric acid?

Sara Seager

No, we don’t.

Brian Resnick

What makes it seem possible for life to exist in sulfuric acid?

Sara Seager

We simply don’t know. I think your questions are the next decades of research, basically.

Brian Resnick

How do you even begin to imagine life in such a different world — life that has to live in conditions that would be deadly for any life on Earth?

Sara Seager

It has to be made up of different building blocks than our life is made up of. Our building blocks — like proteins, and amino acids, and DNA — wouldn’t survive in sulfuric acid. Or life has to have found a way to have a protective shell, made of materials that are resistant to sulfuric acid.

The dance of (potential) life on Venus

The surface of Venus, stitched together in a composite image.
NASA/JPL-Caltech

Brian Resnick

Over the summer, you and your colleagues published a paper speculating on what life on Venus could look like. You describe that it could basically dance in the atmosphere, alternating between an active phase up high and a dormant phase down low. I found it to be kind of beautiful. Can you describe how you came up with this?

Sara Seager

I had to help plug a hole in the concept of life in the atmosphere. That’s where it came from. Life has to live inside the liquid droplets, to be protected from the outside.

But in these droplets — where life is living, reproducing, metabolizing — the droplets would collide and grow.

Over time, like four months or a year or so, the droplets get big enough, so they start settling out of the atmosphere, like rain, but really slowly.

And so my colleagues told me I had to figure out how life could survive. If it all just rains out, it couldn’t stay in the atmosphere for billions of years, or hundreds of millions of years.

Brian Resnick

How did you solve this?

Sara Seager

So I came up with this life cycle idea: as the droplets fall, they evaporate, and we’re left with a dried, spore-like life form. Now that’s not very massive; it stops falling and becomes suspended in a haze layer [lower down in the atmosphere]. And this haze layer is known to exist beneath the clouds of Venus. It’s very stable and long-lived. So the concept is that this haze layer is populated by dried-out spores, which can stay there for days, weeks, months years — and eventually they get updrafted back up to the region that has the right temperature for life, where it can attract liquid, hydrate it, and start their life cycle again.

Brian Resnick

It’s like a living rain, of sorts.

Sara Seager

Right.

Brian Resnick

Why wouldn’t the spore die suspended in that lower layer?

Sara Seager

It’s pretty warm there, so some might die. And this is all just a hypothesis, so it’s not a proven theory or anything, but for this to work, some of them have to live. We have examples on Earth of dried-out spore living a long time.

What it would mean to discover life on Venus

Brian Resnick

Why is it important to do this type of exercise, to be so speculative, and imagine life in a world so seemingly hostile to life?

Sara Seager

If we think about it and couldn’t find any possible way for life to be in the atmosphere indefinitely, that would be bad news for the enthusiasts for life on Venus. Does that make sense?

Brian Resnick

Yeah, if you can’t think of any hypothetical that allows life to survive, it’s hard to make a case to go look for it. Does the life you imagined fit in with in the new discovery of the phosphine gas?

Sara Seager

Yes. Well, it was motivated by the phosphine work.

Brian Resnick

What would it mean to find life on Venus?

Sara Seager

I think it would mean that if there’s life there, it has to be so different from Earth, and that we could show that it had a unique origin. It would just give us confidence that life can originate almost anywhere. And that would mean that our galaxy would be teeming with life. All the planets around other stars. It just sort of ups our thinking that there could be life everywhere.

Brian Resnick

Are you talking about a second genesis of life happening separately on Venus? Or would we have to figure out if there’s a common origin of life in our solar system? That something seeded life on both Earth and Venus?

Sara Seager

We’d have to figure it out.

How to find life on Venus, once and for all

Brian Resnick

What are the next steps, ideally?

Sara Seager

Our ideal next step would be to send a spacecraft or spacecrafts, plural, to Venus, that could involve a probe going into the atmosphere and measuring gases confirming phosphine, looking for other gases, looking for complex molecules that might indicate life, and maybe even searching for life itself.

Brian Resnick

Anyone working on that?

Sara Seager

Rocket Lab had mentioned about a month ago that they were planning to send a rocket to Venus. There are two NASA discovery class missions under a phase A competition [meaning they’re just mission proposals and need to be greenlit]. if they get selected for launch, they will get to go. Russia and India are planning to send something there. And I’ve started to lead a privately funded study. It’s not a mission. It’s just a study of what it would really take.

Brian Resnick

Can we answer this question — is there life on Venus — in our lifetimes?

Sara Seager

I think it is answerable in a human lifetime.

Brian Resnick

Is too much time and money spent on finding life on Mars? Venus seems to be neglected in terms of big NASA missions.

Sara Seager

Well, we don’t have infinite resources, unfortunately, but it sure would be nice to see more spent on Venus. We haven’t explored Venus for a very long time. You’d have to look up when the last time the US went to Venus. [It was the Magellan mission that launched in 1989.]

Brian Resnick

What would you love the public to think about and dwell on with this topic?

Sara Seager

Our solar system, our galaxy, our universe is full of mysteries. We’d like to solve them, but some end up being unsolvable and they just leave us in limbo. So hopefully that’s not going to be the case here.


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Coronavirus scientists

Scientists may know where coronavirus originated, study says – Fox News

Months into the coronavirus pandemic, researchers are still investigating the actual event where the crossover of the novel coronavirus from animals to humans occurred. A team of scientists may have discovered the answer to the question many have been asking for months, according to a study published in Nature Microbiology.

The group of scientists from the United States, China, and Europe compared mutation patterns of SARS-CoV-2, the virus that causes COVID-19, to other viruses, and created an evolutionary history of the related viruses. They discovered the lineage responsible for producing the virus that created the COVID-19 pandemic has been present in bats, according to the study.

Scientists discovered the lineage responsible for producing the virus that created the COVID-19 pandemic has been present in bats, according to the study. 

Scientists discovered the lineage responsible for producing the virus that created the COVID-19 pandemic has been present in bats, according to the study. 
(iStock)

“Collectively our analyses point to bats being the primary reservoir for the SARS-CoV-2 lineage. While it is possible that pangolins, or another hitherto undiscovered species, may have acted as an intermediate host facilitating transmission to humans, current evidence is consistent with the virus having evolved in bats resulting in bat sarbecoviruses that can replicate in the upper respiratory tract of both humans and pangolins,” the study authors said in the published report.

The novel coronavirus evolved from other bat viruses from 40-70 years ago, the team of researchers said.

‘NO SILVER BULLET’ AGAINST CORONAVIRUS, WARNS WORLD HEALTH ORGANIZATION CHIEF

“The lineage giving rise to SARS-CoV-2 has been circulating unnoticed in bats for decades,” the authors wrote.

In a news release provided to Fox News, the researchers said that SARS-CoV-2 is similar genetically (about 96%) to the RaTG13 coronavirus found in a sample of the Rhinolophus affinis horseshoe bat in 2013 in Yunnan province, China, but it diverged from RaTG13 back in 1969.

“The ability to estimate divergence times after disentangling recombination histories, which is something we developed in this collaboration, may lead to insights into the origins of many different viral pathogens,” Principal investigator, Philippe Lemey, with the Department of Evolutionary and Computational Virology, KE Leuven, said in the release.

The novel coronavirus shares a trait with older members of its lineage regarding the receptor-binding domain (RBD) on its spike protein, which allows it to bind with human receptor cells, the authors said.

“Its receptor-binding motif, important for specificity to human ACE2 receptors, appears to be an ancestral trait shared with bat viruses and not one acquired recently via recombination,” according to the study.

“This means that other viruses that are capable of infecting humans are circulating in horseshoe bats in China,” co-author of the study, David Robertson, who is a professor of computational virology at MRC-University of Glasgow Centre for Virus Research, explained in the release.

The authors of the study said other groups of researchers were incorrect in suggesting that evolutionary changes that occurred in pangolins allowed the novel coronavirus to be transmitted to humans. Robertson said, “SARS-CoV-2’s RBD sequence has so far only been found in a few pangolin viruses.

CORONAVIRUS MAY HELP RESEARCHERS IN FIGHTING CANCER, ACCORDING TO SCIENTIST

“While it is possible that pangolins may have acted as an intermediate host facilitating transmission of SARS-CoV-2 to humans, no evidence exists to suggest that pangolin infection is a requirement for bat viruses to cross into humans,” Robertson also stated in the report. “Instead, our research suggests that SARS-CoV-2 likely evolved the ability to replicate in the upper respiratory tract of both humans and pangolins.”

Implementing systems to monitor human diseases in real-time and better sampling of bats are needed to detect new infectious microorganisms and prevent future pandemics, the authors said in the release.

“The key to successful surveillance,” Robertson said, “is knowing which viruses to look for and prioritizing those that can readily infect humans. We should have been better prepared for a second SARS virus.”

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confounded scientists

Scientists confounded by new findings on universe’s mysterious dark matter – Yahoo News

By Will Dunham

WASHINGTON (Reuters) – Dark matter, mysterious invisible stuff that makes up most of the mass of galaxies including our own Milky Way, is confounding scientists again, with new observations of distant galaxies conflicting with the current understanding of its nature.

Research published this week revealed an unexpected discrepancy between observations of dark matter concentrations in three massive clusters of galaxies encompassing trillions of stars and theoretical computer simulations of how dark matter should be distributed.

“Either there is a missing ingredient in the simulations or we have made a fundamental incorrect assumption about the nature of dark matter,” Yale University astrophysicist Priyamvada Natarajan, a co-author of the study published in the journal Science, said on Friday.

Dark matter is the invisible glue that holds stars together inside a galaxy. It also creates an invisible scaffold that enables galaxies to form clusters. But it has very peculiar properties. It does not emit, absorb or reflect light and does not interact with any known particles.

The bulk of the matter in the universe, about 96%, is thought to be dark matter, with ordinary matter – the visible stuff that makes up stars, planets and people – a mere 4%.

Dark matter’s presence is known only through its gravitational pull on visible matter in space. It differs from the similarly enigmatic and unseen dark energy, which is considered a property of space and is driving the universe’s accelerated expansion. Dark energy is repulsive. Dark matter attracts through gravity.

The new study involved observations from the Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope in Chile.

When the light from distant sources like faraway galaxies travels through matter such as another galaxy or a cluster of them, the light is deflected and bends – a phenomenon called “gravitational lensing,” said astrophysicist and study lead author Massimo Meneghetti of the Observatory of Astrophysics and Space Science in Bologna and National Institute for Astrophysics in Italy.

The new observations showed that gravitational lensing effects produced by galaxies residing inside the huge galaxy clusters were far stronger than current dark matter theory envisioned, suggesting an unexpectedly large concentration of dark matter in these galaxies.

“This is quite surprising,” Meneghetti said.

(Reporting by Will Dunham; Editing by Sandra Maler)

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Scientists Detect New Kind of Black Hole After Massive Collision – ExtremeTech

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We still don’t understand a lot of things about black holes, which hover at the very edge of our scientific knowledge. We do know that black holes seem to fall into two categories; those that result from the collapse of a single large star and supermassive black holes that have millions of billions of solar masses. So-called intermediate-mass black holes (IMBH) between the two extremes have been elusive — until now. Scientists with the LIGO and VIRGO Scientific Collaboration report spotting an IMBH billions of light-years away thanks to peculiar gravitational waves

We have a reasonably good understanding of how stellar-mass black holes form. When a star several times larger than the sun runs out of nuclear fuel, its own mass compresses it into a singularity from which not even light can escape. Supermassive black holes are less well-understood, but the leading theory is that they grow from smaller black holes by pulling in matter and merging with other black holes over many eons. These objects are 100,000 solar masses or more with such strong gravity they can anchor a galaxy. Our galaxy has a supermassive black hole in the center known as Sagittarius A* (pronounced Sagittarius A Star). 

Scientists have spotted several candidate IMBHs, but the LIGO and VIRGO projects provide the best evidence yet. These instruments use laser interferometry to detect gravitational waves from catastrophic events like the collisions of neutron stars and black holes. Scientists can also trace the waves back to the objects that produced them. Recently, the team detected gravitational wave GW190521, which began its journey toward Earth 7 billion years ago when two mid-sized black holes collided. 

Simulated view of a black hole in front of the Large Magellanic Cloud. Credit: Alain R./Wikimedia Commons

According to the study, those black holes were about 85 and 65 times the sun’s mass. That puts them well past the limit for a stellar black hole but far short of a supermassive black hole — they were smack in the middle of no man’s land. The new black hole is about 142 times the sun’s mass, and that’s still an IMBH. By comparison, the supermassive Sagittarius A* is about 4 million solar masses. 

This discovery raises a few interesting lines of investigation. Since both of the colliding black holes were larger than a stellar-mass black hole, where did they come from? Could they be the result of past collisions? Will this new IMBH continue growing now that it has enough gravity to vacuum up more material? All we can say right now is these “impossible” black holes do exist. We just don’t know why yet.

Top photo credit: Mark Myers/OzGrav

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Scientists discover way to make quantum states last 10,000 times longer – Phys.org

UChicago scientists discover way to make quantum states last 1src,srcsrcsrc times longer
A team of scientists at the University of Chicago’s Pritzker School of Molecular Engineering announced the discovery of a simple modification that allows quantum systems to stay operational—or “coherent”—10,000 times longer than before. Credit: University of Chicago

If we can harness it, quantum technology promises fantastic new possibilities. But first, scientists need to coax quantum systems to stay yoked for longer than a few millionths of a second.

A team of scientists at the University of Chicago’s Pritzker School of Molecular Engineering announced the discovery of a simple modification that allows to stay operational—or “coherent”—10,000 times longer than before. Though the scientists tested their technique on a particular class of quantum systems called solid-state qubits, they think it should be applicable to many other kinds of quantum systems and could thus revolutionize quantum communication, computing and sensing.

The study was published Aug. 13 in Science.

“This breakthrough lays the groundwork for exciting new avenues of research in quantum science,” said study lead author David Awschalom, the Liew Family Professor in Molecular Engineering, senior scientist at Argonne National Laboratory and director of the Chicago Quantum Exchange. “The broad applicability of this discovery, coupled with a remarkably simple implementation, allows this robust coherence to impact many aspects of quantum engineering. It enables new research opportunities previously thought impractical.”

Down at the level of atoms, the world operates according to the rules of quantum mechanics—very different from what we see around us in our daily lives. These different rules could translate into technology like virtually unhackable networks or extremely powerful computers; the U.S. Department of Energy released a blueprint for the future quantum internet in an event at UChicago on July 23. But fundamental engineering challenges remain: Quantum states need an extremely quiet, stable space to operate, as they are easily disturbed by coming from vibrations, temperature changes or stray .

Thus, scientists try to find ways to keep the system coherent as long as possible. One common approach is physically isolating the system from the noisy surroundings, but this can be unwieldy and complex. Another technique involves making all of the materials as pure as possible, which can be costly. The scientists at UChicago took a different tack.

“With this approach, we don’t try to eliminate noise in the surroundings; instead, we “trick” the system into thinking it doesn’t experience the noise,” said postdoctoral researcher Kevin Miao, the first author of the paper.

UChicago scientists discover way to make quantum states last 1src,srcsrcsrc times longer
A team of scientists at the University of Chicago’s Pritzker School of Molecular Engineering announced the discovery of a simple modification that allows quantum systems to stay operational—or “coherent”—10,000 times longer than before. Credit: University of Chicago

In tandem with the usual electromagnetic pulses used to control quantum systems, the team applied an additional continuous alternating magnetic field. By precisely tuning this field, the scientists could rapidly rotate the electron spins and allow the system to “tune out” the rest of the noise.

“To get a sense of the principle, it’s like sitting on a merry-go-round with people yelling all around you,” Miao explained. “When the ride is still, you can hear them perfectly, but if you’re rapidly spinning, the noise blurs into a background.”

This small change allowed the system to stay coherent up to 22 milliseconds, four orders of magnitude higher than without the modification—and far longer than any previously reported electron spin system. (For comparison, a blink of an eye takes about 350 milliseconds). The system is able to almost completely tune out some forms of temperature fluctuations, physical vibrations, and electromagnetic noise, all of which usually destroy quantum coherence.

The simple fix could unlock discoveries in virtually every area of quantum technology, the scientists said.

“This approach creates a pathway to scalability,” said Awschalom. “It should make storing quantum information in electron spin practical. Extended storage times will enable more complex operations in quantum computers and allow quantum information transmitted from spin-based devices to travel longer distances in networks.”

Though their tests were run in a solid-state quantum system using , the scientists believe the technique should have similar effects in other types of quantum systems, such as superconducting quantum bits and molecular quantum systems. This level of versatility is unusual for such an engineering breakthrough.

“There are a lot of candidates for quantum technology that were pushed aside because they couldn’t maintain quantum coherence for long periods of time,” Miao said. “Those could be re-evaluated now that we have this way to massively improve coherence.

“The best part is, it’s incredibly easy to do,” he added. “The science behind it is intricate, but the logistics of adding an alternating magnetic field are very straightforward.”



More information:
K. C. Miao et al, “Universal coherence protection in a solid-state qubit,” Science, Aug. 13, 2020. DOI: 10.1126/science.abc5186

Citation:
Scientists discover way to make quantum states last 10,000 times longer (2020, August 13)
retrieved 14 August 2020
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