PM Boris Johnson back to work as UK coronavirus problems mount

Mexico City, Jun 13: The number of people, who have died of COVID-19 in Mexico, has risen by 544 to 16,448 within the past 24 hours, Jose Luis Alomia, the director of epidemiology at the Health Ministry, said.

He also said on late Friday that the number of confirmed coronavirus cases had increased by 5,222 to 139,196 within the same period of time.

A day earlier, the Latin American nation has recorded 4,790 new confirmed cases of the coronavirus, with 587 fatalities.

The World Health Organization declared the COVID-19 outbreak a pandemic on March 11. To date, more than 7.6 million people have been infected with the coronavirus worldwide, with over 425,000 fatalities, according to Johns Hopkins University.

Tokyo, April 6: Japan Prime Minister Shinzo Abe is planning to declare a state of emergency in view of the surging cases of coronavirus in the country, especially in Tokyo and other large cities, government sources said on Monday.

Pressure had been mounting on Abe to make the declaration amid a spurt in COVID-19 cases recently, with calls for the move from Tokyo Governor Yuriko Koike and the Japan Medical Association intensifying, Xinhua news agency reported.

The Tokyo metropolitan government, along with healthcare specialists, said that the number of hospital beds available for coronavirus patients will soon reach capacity, with the health ministry rapidly trying to secure more beds.

Adding to pressure on the government to demonstrably bolster its preventive and countermeasures to the spread of the virus, a panel of government experts warned recently that the country's healthcare system could collapse if coronavirus cases continue to spike.

The healthcare system in Tokyo and four other prefectures are under increased strain and "drastic countermeasures need to be taken as quickly as possible," the experts said.

As of Sunday, 143 new cases of COVID-19 were recorded in Tokyo, a record daily high for the capital, bringing the total to 1,034, with Japan's health ministry and local governments adding that nationwide cases rose to 3,531 as of Sunday afternoon.

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.