Indian-origin woman doctor held for female circumcision in US

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.

Jakarta, Mar 15: Indonesia's transport minister is in intensive care after testing positive for the novel coronavirus, an official has said, as schools and tourist attractions were ordered to close over the health threat.

Transportation Minister Budi Karya Sumadi was receiving treatment at an army hospital in Jakarta, State Secretary Pratikno said on Saturday.

A hospital spokesman said Sumadi was encountering difficulty breathing but that his condition was improving.

Pratikno said Sumadi was involved in virus mitigation efforts, particularly the evacuation of Indonesians from epicenters of the outbreak, and that President Joko Widodo had called for tests to be carried out on other ministers.

Cases of the virus in Indonesia, the world's fourth most populous country, have jumped from zero two weeks ago to 96, with five deaths, according to government spokesperson Achmad Yurianto.

He also said the virus has spread outside Greater Jakarta to Bandung in West Java, Solo in Central Java, Manado in North Sulawesi, Pontianak in West Kalimantan, as well as holiday havens Yogyakarta and Bali.

Following the increase, the government on Saturday established a task force on COVID-19 mitigation.

Jakarta's Governor Anies Baswedan announced that schools would close for two weeks starting Monday, and ordered the closure of city-owned tourist attractions, such as Ragunan Zoo and Ancol beach.

He emphasized that Jakarta would not be locked down but urged people "to be responsible" and called for social distancing when possible.

Similarly, the administration of Solo, Central Java, Friday announced that schools and tourist attractions would close after a coronavirus patient died in the region.

The World Health Organization has said it is particularly concerned about high-risk nations with weaker health systems, which who may lack the facilities to identify cases.

A day after declaring the coronavirus outbreak to be pandemic this week, WHO chief Tedros Adhanom Ghebreyesus called Indonesia's president Widodo and both agreed to "scale up cooperation."

Beijing, May 24: The Chinese virology institute in the city where COVID-19 first emerged has three live strains of bat coronavirus on-site, but none match the new contagion wreaking chaos across the world, its director has said.

Scientists think COVID-19 -- which first emerged in Wuhan and has killed some 340,000 people worldwide -- originated in bats and could have been transmitted to people via another mammal.

But the director of the Wuhan Institute of Virology told state broadcaster CGTN that claims made by US President Donald Trump and others that the virus could have leaked from the facility were "pure fabrication".

"Now we have three strains of live viruses... But their highest similarity to SARS-CoV-2 only reaches 79.8 percent," she said, referring to the coronavirus strain that causes COVID-19.

US demands immediate start to WHO review

The United States called on the World Health Organisation on Friday to begin working immediately on investigating the source of the novel coronavirus, as well as its handling of the response to the pandemic.

One of their research teams, led by Professor Shi Zhengli, has been researching bat coronaviruses since 2004 and focused on the "source tracing of SARS", the strain behind another virus outbreak nearly two decades ago.

"We know that the whole genome of SARS-CoV-2 is only 80 percent similar to that of SARS. It's an obvious difference," she said.

"So, in Professor Shi's past research, they didn't pay attention to such viruses which are less similar to the SARS virus."

Conspiracy rumours that the biosafety lab was involved in the outbreak swirled online for months before Trump and US Secretary of State Mike Pompeo brought the theory into the mainstream by claiming that there is evidence the pathogen came from the institute.

The lab has said it received samples of the then-unknown virus on December 30, determined the viral genome sequence on January 2 and submitted information on the pathogen to the WHO on January 11.

Wang said in the interview that before it received samples in December, their team had never "encountered, researched or kept the virus."

"In fact, like everyone else, we didn't even know the virus existed," she said. "How could it have leaked from our lab when we never had it?"

The World Health Organization said Washington had offered no evidence to support the "speculative" claims.

In an interview with Scientific American, Shi said the SARS-CoV-2 genome sequence did not match any of the bat coronaviruses her laboratory had previously collected and studied.