Trump praises Chinese president Xi Jinping extending tenure 'for life'

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 11: The total death toll in the US from the novel coronavirus pandemic could hit the grim figure of 200,000 by September and expecting a dramatic decrease in COVID-19 cases in the country will be a "wishful thinking , an eminent Indian-American professor has warned.

Ashish Jha, the head of Harvard's Global Health Institute, told CNN on Wednesday that he is not trying to scare people to stay at home rather urged everyone to wear masks, adhere to the social distancing rules and called for ramping up testing and tracing infrastructure.

Anybody who's expecting a dramatic decrease in cases is almost surely engaging in wishful thinking. And if it (COVID numbers) stays just flat for the next three months, we're going to hit 200,000 deaths sometime in September and that is just awful, Jha said.

Jha said the 200,000 death toll is not just a guess . Currently 800-1000 people are dying daily in America from the virus and all data suggest that the situation is going to get worse.

We're gonna have increases, but even if we assume that it's going to be flat all summer, that nothing is going to get worse... even if we pick that low number of 800 a day, that is 25,000 (deaths) a month in three and a half months. We're going to add another 88,000 people and we will hit 200,000 sometime in September, Jha said.

The United States is by far the hardest-hit country in the global pandemic, in terms of both confirmed infections and deaths.

According to data by the Johns Hopkins University, the number of coronavirus cases in the US currently is nearly two million and about 112,900 people have died in the country, the most in the world.

When asked about an improvement in states like New York, which had been the epicenter of the COVID19 pandemic in the US, Jha said while coronavirus cases are declining in New York, New Jersey, Connecticut and Massachusetts, the numbers are increasing in states such as Arizona, Florida, Texas, North and South Carolina while the country as a whole is pretty flat.

He said, people should take measures as that will help suppress the virus and ensure people could get back outside safely but he voiced concern that this was not the situation in reality.

We're not doing that and so we're going to unfortunately have another 25,000 deaths a month until September, and then it'll keep going. It's not going to magically disappear. We've got a turn around. This is not the future I want, he said.

Jha said he had expected the situation to improve in the summer months but on the contrary the numbers have continued to rise even in the warm weather.

Summer was supposed to be our better months - warmer weather, people outside, a little less transmission. This is not the time (summer) I was expecting a lot more cases. We're seeing a lot more cases, especially in states like Arizona where the numbers look really scary, he said.

Jha added that he was hopeful that maybe the summer months would give us more of a break. I think I may have been too optimistic on that.

Beijing, Jun 11: Floods and mudslides in south China have uprooted hundreds of thousands of people and left dozens dead or missing, state media reported Thursday.

The bad weather has wreaked havoc on popular tourist areas that had already been battered by months of travel restrictions during the coronavirus outbreak.

Torrential downpours unleashed floods and mudslides that caused nearly 230,000 people to be relocated and destroyed more than 1,300 houses, official state news agency Xinhua reported, citing the Ministry of Emergency Management.

In southern Guangxi Zhuang Autonomous Region, six people were reported dead and one missing, Xinhua said.

Streets were waterlogged in popular tourist destination Yangshuo, forcing residents and visitors to evacuate on bamboo rafts.

The local government said more than 1,000 hotels had been flooded and more than 30 tourist sites damaged.

One owner of a family-run hotel told Xinhua that the guest rooms were submerged in one metre (three feet) of rainwater.

The extreme weather has dealt a hefty blow to the region's tourism sector, which is still reeling from the COVID-19 epidemic.

The emergency management ministry said there were direct economic losses of over 4 billion yuan (more than $550 million) from the flooding, Xinhua reported.

In Hunan Province, at least 13 people were killed in rain-triggered disasters, and another eight people are missing or killed in southwestern Guizhou province, according to the local emergency response departments, Xinhua said.

The heavy downpours began at the beginning of June and have led to "dangerously high water levels" in 110 rivers, Xinhua reported.

Further rainstorms are expected in the next few days across the south.