At least 10 dead, several injured in Lahore blast

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, May 28: US President Donald Trump has warned social media giants that his government could "strongly regulate" or "close them down" after Twitter fact-checked one of his tweets for the first time.

"Republicans feel that Social Media Platforms totally silence conservatives voices," Xinhua news agency reported citing Trump as saying in a tweet to his 80 million followers on Wednesday.

"We will strongly regulate, or close them down, before we can ever allow this to happen."

Later in the day, he said that Twitter "has now shown everything we have been saying about them... is correct" and vowed "big action to follow".

The President's remarks came after Twitter slapped a warning label on one of his tweets on Tuesday, cautioning readers "Trump makes unsubstantiated claim that mail-in ballots will lead to voter fraud".

It was in response to Trump's tweet, without providing evidence, said: "There is NO WAY (ZERO!) that Mail-In Ballots will be anything less than substantially fraudulent."

Also Read: Obama was ‘grossly incompetent president’, says Donald Trump
It is unclear what regulatory steps the president could take without new laws passed by Congress, the BBC reported.

The White House is yet to offer further details.

Earlier, Trump has accused Twitter of interfering in this year's US presidential election scheduled for November, saying the company was "completely stifling free speech, and I, as president, will not allow it to happen".

With more than 52,000 tweets currently to his name, Trump is a prolific tweeter and relies on the platform to disseminate his views to millions of people.

He has used Twitter to launch attacks on opponents, with targets ranging from North Korean leader Kim Jong-un to his political rivals in the US.

In 2017 he used anti-Muslim tweets aimed at London Mayor Sadiq Khan to serve a domestic political purpose of warning about immigration.

New York, Mar 6: A 23-year-old Indian with a student visa in the US has pleaded guilty to sexual enticement of a minor girl, prosecutors have said.

Sachin Aji Bhaskar faces a maximum penalty of life in prison.

He pleaded guilty before Senior US District Judge William M Skretny to sexual enticement of a minor.

The charge carries a minimum penalty of 10 years in prison, a maximum penalty of life in prison, a fine of USD 250,000 or both, US Attorney James P Kennedy said.

Prosecutors alleged that Bhaskar communicated by text and email with an 11-year-old girl for the purpose of engaging in sexual activity.

Through those communications, Bhaskar enticed the victim to engage in a sexual activity with him in August, 2018, they said.

The sentencing in the case is scheduled for June 17.