Rahul Gandhi accuses govt of asking soldiers to buy their clothes, shoes

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.

Six months since the new coronavirus outbreak, the pandemic is still far from over, the World Health Organization said Monday, warning that "the worst is yet to come".

Reaching the half-year milestone just as the death toll surpassed 500,000 and the number of confirmed infections topped 10 million, the WHO said it was a moment to recommit to the fight to save lives.

"Six months ago, none of us could have imagined how our world -- and our lives -- would be thrown into turmoil by this new virus," WHO chief Tedros Adhanom Ghebreyesus told a virtual briefing.

"We all want this to be over. We all want to get on with our lives. But the hard reality is this is not even close to being over.

"Although many countries have made some progress, globally the pandemic is actually speeding up.

"We're all in this together, and we're all in this for the long haul.

"We will need even greater stores of resilience, patience, humility and generosity in the months ahead.

"We have already lost so much -- but we cannot lose hope."

Tedros also said that the pandemic had brought out the best and worst humanity, citing acts of kindness and solidarity, but also misinformation and the politicisation of the virus.

In an atmosphere of global political division and fractures on a national level, "the worst is yet to come. I'm sorry to say that," he said.

"With this kind of environment and condition, we fear the worst."

New Delhi, Feb 9: Calling India a "long-standing friend", Sri Lankan Prime Minister Mahinda Rajapaksa on Saturday thanked Prime Minister Narendra Modi for visiting his country in the aftermath of last year's Easter Sunday terror attacks and outlined that New Delhi has always helped Colombo in its fight against terrorism.

In a joint press briefing with PM Modi, Mahinda Rajapaksa said he hopes that India will continue to help Sri Lanka fight terrorism.

Mahinda Rajapaksa expressed his gratitude to PM Modi for the neighbourhood first policy and the priority India gives to Sri Lanka.

"We had agreed that our cooperation is multifaceted and priority is given to a number of areas including security, economy, culture and social sectors. Part of our discussions centered on cooperation with regard to the security of the two countries. India has always assisted Sri Lanka to enhance our capacity, capabilities in intelligence and counter-terrorism. We look forward to getting continued support in this regard," he said.

"I thank the Prime Minister for visiting Sri Lanka in the aftermath of the Easter Sunday terror attacks that provided us with immense strength to come to terms with the tragedy. We also appreciate Prime Minister Modi's $400 million line of credit to enhance the economy of Sri Lanka and another $50 million line of credit for fighting terrorism," he added.

The Sri Lankan president urged PM Modi to consider further assistance to expand housing projectS all over Sri Lanka to benefit people from rural areas.

"The Prime Minister and I discussed how Sri Lanka and India can work together in the field of economy. India is among the world's fastest growing economies. I discussed with PM Modi how Sri Lanka could benefit from certain economic sectors where India is in a strong position," he said.

Concluding his statement, Mahinda Rajapaksa said, "India is our closest neighbour and a long-standing friend. The close historical links...provided a solid foundation to our ties."