5 women accuse Donald Trump of groping, sexual harassment

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.

Jun 24: The coronavirus tally in Pakistan reached 188,926 with the detection of 3,892 new cases in the last 24 hours, the health ministry said on Wednesday.

Sixty more people died due to the viral infection, taking the death toll to 3,755.

As many as 3,337 patients are in critical condition across the country, the ministry said.

With the detection of 3,892 new cases in the last 24 hours, the coronavirus tally in the country now stands at 188,926, it said.

Sindh reported the maximum number of 72,656 cases, followed by 69,536 in Punjab, 23,388 in Khyber-Pakhtunkhwa, 11,483 in Islamabad, 9,634 in Balochistan, 1,337 in Gilgit-Baltistan and 892 in Pakistan-occupied Kashmir (Pok).

Health authorities have so far conducted 1,150,141 coronavirus tests, including 23,380 in the last 24 hours.

A total of 77,754 patients have recovered so far from the disease.

Hundreds of thousands of people across the world are joining the anti-racism demonstrations days after the killing of George Floyd in United Sates. 

The protests are being held in cities including London, Manchester, Cardiff, Leicester and Sheffield.

Demonstrators attached ropes to the statue of Edward Colston before pulling it down to cheers and roars of approval from the crowd. Images on social media show the statue was eventually rolled into the city's harbour. 

It was not the only statue targeted on Sunday. In Brussels, protesters clambered onto the statue of former King Leopold II and chanted "reparations".

The word "shame" was also graffitied on the monument, reference perhaps to the fact that Leopold is said to have reigned over the mass death of 10 million Congolese.

In London, thousands of people congregated around the US embassy for the second day running.

While protests were mainly peaceful, there were some scuffles near the office of Prime Minister Boris Johnson and outside the Parliament gates.

In Hong Kong, about 20 people staged a rally in solidarity with the Black Lives Matter movement on Sunday outside the US consulate in the semi-autonomous Chinese city.

"It's a global issue," Quinland Anderson, a 28-year-old British citizen living in Hong Kong, told The Associated Press news agency.

"We have to remind ourselves despite all we see going on in the US and in the other parts of the world, Black lives do indeed matter."

Several dozen demonstrators took part in a Black Lives Matter protest held in Tel Aviv's central Rabin Square.

A rally in Rome's sprawling People's Square was noisy but peaceful, with the majority of protesters wearing masks to protect against coronavirus. Participants listened to speeches and held up handmade placards saying "Black Lives Matter" and "It's a White Problem".

In Spain, several thousand people gathered on the streets of Barcelona and at the US embassy in Madrid.

Many in Madrid carried homemade signs reading "Black Lives Matter", "Human rights for all" and "Silence is pro-racist".

"We are not only doing this for our brother George Floyd," said Thimbo Samb, a spokesman for the group that organised the events in Spain mainly through social media. "Here in Europe, in Spain, where we live, we work, we sleep and pay taxes, we also suffer racism."