UP govt preparing plan to open shelters for stray cows: Yogi

London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.

Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.

In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.

"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.

According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.

They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.

These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.

In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.

The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.

Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.

The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.

"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.

However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.

They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.

This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.

Washington, Mar 8: An attendee at last week's Conservative Political Action Conference (CPAC), which also saw the participation of US President Donald Trump, has tested positive for COVID-19, the American Conservative Union (ACU) said.

The exposure occurred prior to the conference held in National Harbor, Maryland, just south of Washington D.C., Xinhua news agency quoted the ACU as saying in a statement on Saturday.

A New Jersey hospital tested the person, and the Centers for Disease Control and Prevention (CDC) confirmed the positive result, said the statement.

"The individual is under the care of medical professionals in the state of New Jersey, and has been quarantined," it said.

Trump and Vice President Mike Pence spoke at the gathering, which took place from February 26-29.

Also present at the event were a number of administration and cabinet officials, including Secretary of State Mike Pompeo, Health and Human Services Secretary Alex Azar, and newly-appointed White House Chief of Staff Mark Meadows.

White House Press Secretary Stephanie Grisham said in a statement Saturday that the White House was aware of the development.

"At this time there is no indication that either President Trump or Vice President Pence met with or were in close proximity to the attendee," Grisham said in a statement.

"The President's physician and US Secret Service have been working closely with White House Staff and various agencies to ensure every precaution is taken to keep the First Family and the entire White House Complex safe and healthy."

The news emerged as Washington D.C. and neighbouring state of Virginia respectively confirmed their first cases of COVID-19 on Saturday.

In a press conference on Saturday night, Washington D.C. Mayor Muriel Bowser said a resident in his 50s showed symptoms of a respiratory virus in February. He was admitted to a hospital in the District on March 5.

The patient had no history of recent international travel, nor had he been exposed to anyone who was confirmed to be infected, according to Bowser.

The Mayor said D.C. health authorities were investigating the man's contact with other people before he went to the hospital.

A US Marine assigned to Fort Belvoir in Fairfax County, Virginia, tested positive on Saturday for COVID-19 and is currently being treated at Fort Belvoir Community Hospital, according to a Pentagon spokesman.

"The Marine recently returned from overseas where he was on official business," tweeted Jonathan Rath Hoffman, adding that Secretary of Defence Mark Esper and the White House have been briefed.

As of Saturday night, more than 420 cases of COVID-19 were reported in the US with 17 deaths, according to the Center for Systems Science and Engineering at Johns Hopkins University.

New Delhi, Apr 19: With 1,334 fresh cases of coronavirus reported in the last 24 hours, the total number of confirmed cases of COVID-19 in India has reached 15,712 including 507 deaths, said Lav Aggarwal, Joint Secretary, Health and Family Welfare, here on Sunday.

As many as 2,231 people have recovered from the disease so far, said Aggarwal during the daily media briefing on the coronavirus. "This equals 14.1 per cent of the total cases," he added.

"A total of 15,712 confirmed cases have been reported in India including 507 deaths and 2,231 people, who were COVID-19 positive, have recovered. Out of the total deaths, 27 deaths have been reported in the last 24 hours," said Aggarwal.

The Joint Secretary said that no new case was reported in Mahe in Puducherry and Karnataka's Kodagu in the last 28 days.

"A total of 54 other districts beside these two in 23 States/Union Territories did not report any cases in the last 14 days," he said.

He informed that there are 755 dedicated COVID-19 hospitals and 1,389 dedicated health care centres in the country, which takes the total dedicated facilities where severe or critical patients can be treated to 2,144.