Pak downgrading ties attempt to present alarming picture to world: Modi govt

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.

New Delhi, April 4: With 355 new cases reported in the last 12 hours, India's tally of coronavirus positive cases rose to 2,902, said the ministry of Health and Family Welfare on Saturday.

Out of 2,902 cases, 2,650 are active cases and 184 have been cured or discharged or have migrated.

The total number of deaths reported due to the disease rose to 68 on Saturday.

According to the Ministry of Health and Family Welfare, Maharashtra is the worst-hit state with 423 cases. Tamil Nadu is the next most affected state with 411 cases.

The number of COVID-19 cases in Delhi also rose to 386.

The Tablighi Jamaat event in Delhi has emerged as a hotspot for COVID-19 after several positive cases from across India were linked to the gathering including deaths in Maharashtra, Karnataka, and Telangana.

An FIR was earlier registered against Tablighi Jamaat head Maulana Saad and others under the Epidemic Disease Act 1897, in the national capital.

Mumbai, Mar 29: Virologist Minal Dakhave Bhosale led from the front to create India's first coronavirus testing kit even when she was in the last stage of her pregnancy.

Bhosale's efforts paid the price with her team delivering the testing kit in a record time of six weeks.

Bhosale gave birth to a baby girl just a day before submitting the kit to the authorities for evaluation.

"It was like giving birth to two babies," Bhosale told PTI over the phone.

The virologist said both the journeys - that happened in parallel - were not without challenges.

"There were complications in the pregnancy while work on the test kit was on. The baby was delivered through cesarean," she said.

Bhosale said she felt that it was the right time to serve the people to help them in combating the coronavirus threat.

"I had been working for five years in this field and if I don't work in emergency situations when my services are needed the most, then what is the use?" she said.

Though Bhosale was not able to visit the office due to the pregnancy, she was guiding a team of 10 persons working on the project at Mylab Discovery in Pune.

The strong bonds forged with the team over the years and their support made it possible, she said.

Company's co-founder Shrikant Patole said just like drug discovery, test kits too go through a lot of quality checks to improve the precision.

He credited Bhosale for the success of the project.

The COVID-19 testing kit delivered by Bhosale's team will reduce the time taken for delivering a result to 2.5 hours from the prevalent practice of eight hours.

A pioneering approach to testing without compromising on the results was adopted, Bhosale said.

The Maylab test kit will cost Rs1,200, a quarter of Rs 4,500 per kit that the government has been spending on testing so far.

"I'm happy that I could do something for the country," Bhosale said.

As of Friday, only 27,000 of the 1.3 billion people were tested for the virus in the country.

According to experts, high scale testing is essential because it alone can ensure an early diagnosis of COVID-19 and lower down the fatalities.

The company is confident of ramping up the capacity at its plant in Lonavala to deliver 100,000 kits a week, Patole said.

He said the authorities are helping the company, including giving priority for shipping of the raw materials.