New US Prez should meet Modi in 100 days: US think tank

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.

Beijing, Mar 12: The number of fresh infections at the epicentre of China's coronavirus epidemic dropped to a new low on Thursday but the country imported more cases from abroad.

Another 11 people died, the lowest daily increase since late January, bringing the toll in China to 3,169 deaths, according to the National Health Commission.

There were only eight new cases in Wuhan, the city where the virus first emerged in December before growing into a national crisis and a pandemic.

It is the first time that new cases in Wuhan, the capital of Hubei province, have fallen to single-digits since figures started to be reported in January.

With cases falling dramatically in recent weeks, authorities this week began to loosen some restrictions on Hubei's 56 million people, who have been under quarantine since late January.

Healthy people living in low-risk areas of the province can now travel within Hubei. While Wuhan is not included, some of the city's companies were told they could resume work.

Only one other non-imported case was recorded elsewhere in the country.

But as global hotspots emerge elsewhere, China fears that cases arriving from abroad could undermine its progress.

On Thursday there were six more imported cases reported, bringing the total of infections from overseas to 85, health officials said.

Beijing has ordered a 14-day quarantine for everyone arriving in the city from any country.

Travellers flying into Beijing Capital International Airport from high-risk countries are now handled separately from other passengers.

A total of 80,793 people have now been infected in China.

President Xi Jinping said this week during his first visit to Wuhan since the crisis erupted that the spread of the disease has been "basically curbed" in China.

Apr 26: The remarkable story of an airman who overcame prejudice to become one of only a handful of Indian fighter pilots in the First World War has emerged in newly-released archive files by the UK's Commonwealth War Graves Commission (CWGC).

Lieutenant Shri Krishna Chanda Welinkar is one of the thousands of moving stories from the war preserved in family correspondence and being brought alive as part of a digitisation project.

The never-before-published files contain thousands of letters, pictures and other papers sent between the Commission and the next of the kin of First World War dead.

Among them is the story of Welinkar, who hailed from Bombay in colonial India. After much hardship and discrimination, he eventually became a pilot and went missing while on patrol over the skies above the Western Front in June 1918.

His family had to wait nearly three years before they finally knew for certain that he had died, and his grave was located.

“For everyone who died in the First World War, there was inevitably a partner, parent or child back home who had questions. The heartbreaking letters in CWGC's archive give us an insight into what it was like for those families trying to come to terms with their loss,” said Andrew Fetherston, chief archivist for CWGC.

“They are stories that show desperate searches for closure, former enemies uniting and, on many occasions, the sad realisation that a missing loved one would always remain so. We are pleased to be able to make this invaluable piece of World War history accessible to a new generation and help deepen our understanding of how the First World War impacted those who were left behind,” he said.

Welinkar was one of the 1.3 million Indians who answered the call to fight for the British Empire. Nearly 74,000 never saw their homeland again and are remembered today in cemeteries and memorials throughout the world, including France, Belgium, the Middle East and Africa.

Welinkar was a well-educated man studying at Cambridge University. He trained to become an aviator in Middlesex and wished to join the Royal Flying Corps, later known as the Royal Air Force.

Upon attempting to enlist, Welinkar encountered the same prejudices as his other fellow Indian airmen and was encouraged to become an air mechanic instead.

He was eventually given a commission in the Royal Flying Corps as an Officer. In 1918, he was posted to France and patrolled the skies above the Western Front.

In June 1918, Lieutenant Welinkar embarked on what would be his final patrol; he did not return and was reported missing. His fate remained unknown for many months afterwards.

The newly-released e-files chronicle the remarkable discovery of Welinkar and his final resting place long after the war had ended. Colonel Barton, who knew Welinkar, acted on behalf of his mother and helped find her missing son. They spoke to former enemies and honed their search to the grave of an unidentified man, buried by the Germans as “Oberleutnant S.C. Wumkar” in a grave in Rouvroy, Belgium.

The body was later moved and reinterred in Hangard Communal Cemetery Extension but it wasn't until the vital clue, found in the original German burial records in February 1921, that it was confirmed beyond doubt this grave was of Welinkar's.

In May 1921, Colonel Barton, on behalf of Welinkar's mother, requested that a Commission headstone be placed on the grave with the following personal inscription: “To the Honoured Memory of One of the Empire's Bravest Sons”.

This records – known as Enquiry Files – are part of a collection of nearly 3,000 files which have never been made available to the public before. Nearly half have been digitised so far, alongside a previously unreleased collection of more than 16,000 photographs held in negatives in the Commission's archive.

The files, internally referred to simply as E-Files, contain correspondence between the CWGC and the next of kin of the war dead. They often contain letters, typed memos between Commission staff and on occasion photos, maps and diagrams.

CWGC only holds an enquiry file for a small proportion of the 1.7 million people it commemorates from the Commonwealth. Today it is only possible to release those surviving records from the First World War because correspondence with families of Second World War casualties often involves people still alive today and cannot be made public for many years, due to the UK's data protection rules.

To date, more than 1,300 of the surviving 3,000 First World War enquiry files have been digitised.

The CWGC commemorates the 1.7 million Commonwealth servicemen and women who died during the two World Wars. It also holds and updates an extensive and accessible records archive, while operating over 23,000 locations in more than 150 countries and territories.