US virus cases surpass 850,000 mark

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, Jul 2: Former US Ambassador to the UN, Nikki Haley, on Wednesday (local time) hailed India's action to ban 59 apps linked to Chinese firms including Tik Tok and said New Delhi is continuing to show it will not back down from China's aggression.

"Good to see India banning 59 popular apps owned by Chinese firms, including TikTok, which counts India as one of its largest markets. India is continuing to show it won't back down from China's aggression," Haley tweeted.

The Indian government on Monday announced that it had decided to block 59 apps in view of the information available that "they are engaged in activities which are prejudicial to sovereignty and integrity of India, defence of India, the security of the state and public order".

Information Technology Minister, Ravi Shankar Prasad said that the government has banned the apps for the safety, security, defense, sovereignty, and integrity of India.

Haley'='s remarks come after US Secretary of State Mike Pompeo welcomed India''s ban on the Chinese apps and stressed that the move would "boost India''s integrity and national security".

"We welcome India''s ban on certain mobile apps. India''s clean app approach will boost India's sovereignty and boost integrity and national security," Pompeo said.

New Delhi, May 28: Twitter CEO Jack Dorsey today reinforced his stance on pointing out "incorrect or disputed information about elections globally", a day after US President Donald Trump threatened to shutter social media over Twitter's actions on his posts.

Mr Dorsey appealed to "leave our employees out of this" as the face-off with Mr Trump is likely to escalate.

"Fact check: there is someone ultimately accountable for our actions as a company, and that's me. Please leave our employees out of this. We'll continue to point out incorrect or disputed information about elections globally. And we will admit to and own any mistakes we make," Mr Dorsey tweeted.

"This does not make us an 'arbiter of truth.' Our intention is to connect the dots of conflicting statements and show the information in dispute so people can judge for themselves. More transparency from us is critical so folks can clearly see the why behind our actions," said the Twitter CEO.

Fact check: there is someone ultimately accountable for our actions as a company, and that's me. Please leave our employees out of this. We'll continue to point out incorrect or disputed information about elections globally. And we will admit to and own any mistakes we make.

— jack (@jack) May 28, 2020

"Per our Civic Integrity policy (https://help.twitter.com/en/rules-and-policies/election-integrity-policy), the tweets yesterday may mislead people into thinking they don't need to register to get a ballot (only registered voters receive ballots). We're updating the link on

@realDonaldTrump tweet to make this more clear," Mr Dorsey tweeted.

Twitter had tagged two of Mr Trump's tweets in which he claimed that more mail-in voting would lead to what he called a "rigged election" this November. There is no evidence that attempts are being made to rig the election, and under the tweets Twitter posted a link which read: "Get the facts about mail-in ballots."

Five states in the US already conduct elections primarily by mail-in vote: Utah, Colorado, Hawaii, Washington and Oregon.

For years, Twitter has been accused of ignoring the US President's violation of platform rules with his daily, often hourly barrages of personal insults and inaccurate information sent to more than 80 million followers, news agency AFP reported.

But Twitter's slap on the wrist was enough to drive Mr Trump into a tirade - on Twitter - in which "Republicans feel that Social Media Platforms totally silence conservatives voices. We will strongly regulate, or close them down, before we can ever allow this to happen," Mr Trump said.

He said that an increase in mail-in ballots - seen in some states as vital for allowing people to avoid crowds during the COVID-19 pandemic - will undermine the election.

"It would be a free for all on cheating, forgery and the theft of Ballots," wrote Mr Trump, whose re-election campaign has been knocked off track by the coronavirus crisis. His torrent of angry tweets earned a top-10 trending hashtag: #TrumpMeltdown.

Facebook chief Mark Zuckerberg also waded in to the row, telling Fox News that his social network - still the biggest in the world - has a different policy. "I just believe strongly that Facebook should not be the arbiter of truth of everything that people say online," Mr Zuckerberg said in a snippet of the interview posted online Wednesday by Fox.

"I think, in general, private companies, especially these platform companies, shouldn't be in the position of doing that," he said.

 he claimed that the political right in the US is being censored.

"Republicans feel that Social Media Platforms totally silence conservatives voices. We will strongly regulate, or close them down, before we can ever allow this to happen," Mr Trump said.

He said that an increase in mail-in ballots - seen in some states as vital for allowing people to avoid crowds during the COVID-19 pandemic - will undermine the election.

"It would be a free for all on cheating, forgery and the theft of Ballots," wrote Mr Trump, whose re-election campaign has been knocked off track by the coronavirus crisis. His torrent of angry tweets earned a top-10 trending hashtag: #TrumpMeltdown.

Facebook chief Mark Zuckerberg also waded in to the row, telling Fox News that his social network - still the biggest in the world - has a different policy. "I just believe strongly that Facebook should not be the arbiter of truth of everything that people say online," Mr Zuckerberg said in a snippet of the interview posted online Wednesday by Fox.

"I think, in general, private companies, especially these platform companies, shouldn't be in the position of doing that," he said.