Mexico deports 311 Indians

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.

Hubei, Feb 10: The death toll in the deadly coronavirus outbreak in China and other parts of the world has reached 904, CNN reported citing Chinese authorities on Monday.

The number of infected people globally has now hit the 40,000 mark.

According to the country's health officials, the number of people, who died from coronavirus in the Hubei Province, has risen to 871.

"As of 24:00 on February 9, Hubei Province reported a total of 29,631 cases of new coronavirus pneumonia, including 16,902 cases in Wuhan. 22,160 patients are still being treated in hospitals. 73,127 people remain under medical observation," read the statement from the Chinese Regional Health Committee.

The novel coronavirus was first detected in China's Wuhan city in late December and has since spread to more than 25 countries.

On Sunday, the new coronavirus even surpassed the fatalities caused by the SARS epidemic in 2003.

The World Health Organisation (WHO) has declared a global health emergency in the wake of the outbreak.

Meanwhile, WHO's international expert mission led by Dr Bruce Aylward embarked for China.

Washington, Jul 9: The United States recorded 55,000 new coronavirus cases in 24 hours on Wednesday (Thursday in Malaysia), a tally by Johns Hopkins University showed, bringing its total to 3,046,351 recorded infections since the pandemic began.

The country, the hardest-hit in the world, had earlier on Wednesday passed the grim milestone of three million infections. The actual number is likely far higher due to issues over getting tested in March and April.

The US also added an additional 833 virus deaths, bringing the death toll to 132,195, the Baltimore-based institution showed at 8.30pm (0030 GMT Thursday).

US President Donald Trump regularly downplays the numbers, attributing them to an increase in testing capacity during the month of June.

Coronavirus cases are surging in several southern hotspots including Texas, Florida, Louisiana and Arizona, but the pandemic has almost entirely receded from its former epicentre in New York and the north-east.

Several states have been forced to suspend their reopening processes or even reverse course, with some ordering bars to close again.

On Wednesday morning, Trump called on schools throughout the country to reopen in the fall, lashing out at his own top health agency to ease health and safety requirements aimed at slowing the spread of the virus, such as social distancing.