Note ban: Russia protests on cash shortage for diplomats

Geneva, Apr 23: The World Health Organisation (WHO) on Wednesday (local time) said that the COVID-19 crisis will not end any time soon, with several countries only in the initial stages of the fight against the virus.

"Make no mistake, we have a long way to go. Coronavirus will be with us for a long time. There is no question that stay at home orders and other physical distancing measures have successfully suppressed transmission in many countries," WHO chief Tedros Adhanom Ghebreyesus said in a press conference.

"Most countries are in the early stages of their epidemics. And some, which were affected early in the pandemic, are now starting to see a resurgence in the number of cases," he added.

COVID-19 has infected more than 2.6 million people around the world and a total of 1,83,027 people have died due to coronavirus, according to data from US-based Johns Hopkins University.

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.

President Donald Trump gave a new justification for killing Qassim Suleimani, telling a gathering of Republican donors that the top Iranian general was "saying bad things about our country" before the strike, which led to his decision to authorise his killing. "How much are we going to listen to?" Trump said on Friday, according to remarks from a fundraiser obtained by CNN.

With his typical dramatic flourish, Trump recounted the scene as he monitored the strikes from the White House Situation Room when Suleimani was killed. The president spoke in a ballroom at his Mar-a-Lago club in Palm Beach, Florida, at a Republican event that raised $10 million for Trump's 2020 campaign.

The January 3 killing of Suleimani prompted Iran to retaliate with missile strikes against US forces in Iraq days later and almost triggered a broad war between the two countries. "They're together sir," Trump said military officials told him. "Sir, they have two minutes and 11 seconds. No emotion. Two minutes and 11 seconds to live, sir. They're in the car, they're in an armoured vehicle. Sir, they have approximately one minute to live, sir. Thirty seconds. Ten, 9, 8 ...'"

"Then all of a sudden, boom," he said. "They're gone, sir. Cutting off, I said, where is this guy?" Trump continued. "That was the last I heard from him". It was the most detailed account that Trump has given of the drone strike, which has drawn criticism from some US lawmakers because neither the president nor his advisers have provided public information to back up their statements that Suleimani presented an "imminent" threat to US.

Trump's comments came a day after he warned Iran's supreme leader Ayatollah Ali Khamenei to be "very careful with his words". According to Trump, Khamenei's speech on Friday, in which he attacked the "vicious" US and described UK, France and Germany as "America's lackeys", was a mistake.