Like Bajrang Dal, many Muslims have sacrificed lives for cow protection: RSS chief

The coronavirus can stay aloft for hours in tiny droplets in stagnant air, infecting people as they inhale, mounting scientific evidence suggests.

This risk is highest in crowded indoor spaces with poor ventilation, and may help explain superspreading events reported in meatpacking plants, churches and restaurants.

It’s unclear how often the virus is spread via these tiny droplets, or aerosols, compared with larger droplets that are expelled when a sick person coughs or sneezes, or transmitted through contact with contaminated surfaces, said Linsey Marr, an aerosol expert at Virginia Tech.

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Aerosols are released even when a person without symptoms exhales, talks or sings, according to Marr and more than 200 other experts, who have outlined the evidence in an open letter to the World Health Organization.

What is clear, they said, is that people should consider minimizing time indoors with people outside their families. Schools, nursing homes and businesses should consider adding powerful new air filters and ultraviolet lights that can kill airborne viruses.

What does it mean for a virus to be airborne?

For a virus to be airborne means that it can be carried through the air in a viable form. For most pathogens, this is a yes-no scenario. HIV, too delicate to survive outside the body, is not airborne. Measles is airborne, and dangerously so: It can survive in the air for up to two hours.

For the coronavirus, the definition has been more complicated. Experts agree that the virus does not travel long distances or remain viable outdoors. But evidence suggests it can traverse the length of a room and, in one set of experimental conditions, remain viable for perhaps three hours.

How are aerosols different from droplets?

Aerosols are droplets, droplets are aerosols — they do not differ except in size. Scientists sometimes refer to droplets fewer than 5 microns in diameter as aerosols. (By comparison, a red blood cell is about 5 microns in diameter; a human hair is about 50 microns wide.)

From the start of the pandemic, the WHO and other public health organizations have focused on the virus’s ability to spread through large droplets that are expelled when a symptomatic person coughs or sneezes.

These droplets are heavy, relatively speaking, and fall quickly to the floor or onto a surface that others might touch. This is why public health agencies have recommended maintaining a distance of at least 6 feet from others, and frequent hand washing.

But some experts have said for months that infected people also are releasing aerosols when they cough and sneeze. More important, they expel aerosols even when they breathe, talk or sing, especially with some exertion.

Scientists know now that people can spread the virus even in the absence of symptoms — without coughing or sneezing — and aerosols might explain that phenomenon.

Because aerosols are smaller, they contain much less virus than droplets do. But because they are lighter, they can linger in the air for hours, especially in the absence of fresh air. In a crowded indoor space, a single infected person can release enough aerosolized virus over time to infect many people, perhaps seeding a superspreader event.

For droplets to be responsible for that kind of spread, a single person would have to be within a few feet of all the other people, or to have contaminated an object that everyone else touched. All that seems unlikely to many experts: “I have to do too many mental gymnastics to explain those other routes of transmission compared to aerosol transmission, which is much simpler,” Marr said.

Can I stop worrying about physical distancing and washing my hands?

Physical distancing is still very important. The closer you are to an infected person, the more aerosols and droplets you may be exposed to. Washing your hands often is still a good idea.

What’s new is that those two things may not be enough. “We should be placing as much emphasis on masks and ventilation as we do with hand washing,” Marr said. “As far as we can tell, this is equally important, if not more important.”

Should I begin wearing a hospital-grade mask indoors? And how long is too long to stay indoors?

Health care workers may all need to wear N95 masks, which filter out most aerosols. At the moment, they are advised to do so only when engaged in certain medical procedures that are thought to produce aerosols.

For the rest of us, cloth face masks will still greatly reduce risk, as long as most people wear them. At home, when you’re with your own family or with roommates you know to be careful, masks are still not necessary. But it is a good idea to wear them in other indoor spaces, experts said.

As for how long is safe, that is frustratingly tough to answer. A lot depends on whether the room is too crowded to allow for a safe distance from others and whether there is fresh air circulating through the room.

What does airborne transmission mean for reopening schools and colleges?

This is a matter of intense debate. Many schools are poorly ventilated and are too poorly funded to invest in new filtration systems. “There is a huge vulnerability to infection transmission via aerosols in schools,” said Don Milton, an aerosol expert at the University of Maryland.

Most children younger than 12 seem to have only mild symptoms, if any, so elementary schools may get by. “So far, we don’t have evidence that elementary schools will be a problem, but the upper grades, I think, would be more likely to be a problem,” Milton said.

College dorms and classrooms are also cause for concern.

Milton said the government should think of long-term solutions for these problems. Having public schools closed “clogs up the whole economy, and it’s a major vulnerability,” he said.

“Until we understand how this is part of our national defense, and fund it appropriately, we’re going to remain extremely vulnerable to these kinds of biological threats.”

What are some things I can do to minimize the risks?

Do as much as you can outdoors. Despite the many photos of people at beaches, even a somewhat crowded beach, especially on a breezy day, is likely to be safer than a pub or an indoor restaurant with recycled air.

But even outdoors, wear a mask if you are likely to be close to others for an extended period.

When indoors, one simple thing people can do is to “open their windows and doors whenever possible,” Marr said. You can also upgrade the filters in your home air-conditioning systems, or adjust the settings to use more outdoor air rather than recirculated air.

Public buildings and businesses may want to invest in air purifiers and ultraviolet lights that can kill the virus. Despite their reputation, elevators may not be a big risk, Milton said, compared with public bathrooms or offices with stagnant air where you may spend a long time.

If none of those things are possible, try to minimize the time you spend in an indoor space, especially without a mask. The longer you spend inside, the greater the dose of virus you might inhale.

Bengaluru, Feb 13: Veteran freedom fighter and advisor to the Karnataka Government in Education Reforms HS Doreswamy on Thursday has recommended Chief Minister BS Yediyurappa to make it mandatory for MLA and MLCs to adopt at least three govt Schools in their respective constituencies.

Mr Doreswamy appealed to the Chief Minister to implement the suggestion in the State budget for 2020-21 to be presented by him on March 5.

Addressing a press conference here, Mr Doreswamy, on the higher education sector, stressed the need to appoint highly qualified candidates for Vice Chancellor posts. There is no dearth of talent and eligibility in the State and authorities concerned must ensure that the right person is appointed by taking extreme care".

Mangaluru, Apr 23: An astronomical phenomenon, ‘Zero Shadow Day', will be observed in Mangaluru on April 24 and in Udupi on April 25. 

According to a press release from Poornaprajna Amateur Astronomers’ Club, the wonder will commence and people will see their shadows disappear for a few moments at 12:28 pm.

The phenomenon is called as Zero Shadow Day. If a person takes a candle in a dark room and use it to create a shadow of one’s palm on the wall, the hand will cast shadow on the wall as one moves the hand. But when one places the palm on the wall, there will be no shadow.

In the phenomenon, the sun at these times shines exactly above the heads on these days. In astronomy, this point is called as Zenith. The point in the sky directly above an observer at any given location. So it is quite clear now that on Zero Shadow Day, the sun passes through the Zenith as a result of which, all objects will have minimal or no shadow if they are on the ground.

The reason for this happens on some specific days is concerned with astronomy. The earth spins around on its own axis and causes days and nights. It also revolves around the sun causing a year. But the seasons are caused because the axis is tilted at an angle of 23.5 degrees. It is because of this tilt that the sun rises every day in the east gradually moving towards the north till June 21st and then slowly proceeding towards the south till December 21st every year. “We call these days solstice. This means the sun shines between the Tropic of Cancer and Tropic of Capricorn every day passing by the equator on the days we call equinox,” the release stated.

As the earth moves around the sun and revolves on its own axis, for all the people between Tropic of Cancer and Tropic of Capricorn, the Sun at noon moves father and closer to the zenith passing through zenith twice causing two Zero Shadow Days per year. People at Mangaluru will observe this on April 24 and August 18 every year and People in Udupi will observe this on April 25 and August 17 every year.

Places with same latitudes will observe the same days of Zero Shadow but the time would vary with longitude. For example, people of Bengaluru as they share the latitude with Mangaluru will also observe it on April 24. While the people of Mangaluru will observe their shadows disappear at 12.28pm, people of Bengaluru will observe this at 12:17pm. Places like Moodabidri, Bantwal, Sakleshpur and Hassan will also observe Zero Shadow on April 24.

Places like Brahmavar, Karkala, Sringeri, Kudremukha, Chikkamagaluru will observe the Zero Shadow Day on the same day as Udupi on April 25.