Canadian Prime Minister Justin Trudeau’s wife tests COVID-19 positive

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.

Mumbai, Jan 17: A 68-year-old convict of the 1993 Mumbai serial blasts case, Jalees Ansari, went missing on Thursday morning while being on parole, officials said.

Ansari, a resident of Mominpura in Agripada here who is serving a life term, is suspected to be involved in many bomb blast cases across the country, an official said.

He was on parole for 21 days from the Ajmer Central Prison, Rajasthan, and was expected to surrender before prison authorities on Friday, he said.

During the parole period, he was ordered to visit the Agripada Police Station everyday between 10.30 am and 12 pm to mark his attendance, he said.

However, Ansari did not visit the police station on Thursday during the designated time, the official said.

In the afternoon, his 35-year-old son Jaid Ansari approached the police station with a complaint about his “missing” father, he said.

According to the complaint, Jalees Ansari woke up in the early hoursand told family members he is going to offer namaz, but did not return home.

On his complaint, the Agripada Police registered a missing case, he said.

The Crime Branch of the Mumbai Police and the Maharashtra ATS have launched a massive manhunt to trace him, he said.

Jalees, who is known as Doctor Bomb, was allegedly connected with terror outfits like SIMI and Indian Mujahidin and taught terror groups how to make bombs, he said.

He was also questioned by the NIA in 2011 in connection with the 2008 bomb blast in Mumbai, he said.

New Delhi, Jun 15: On Monday, petrol and diesel prices across the country were raised for the ninth consecutive day by 48 paise and 59 paise, respectively.

Petrol price per litre was raised to Rs 76.26 in New Delhi, Rs 83.17 in Mumbai, Rs 79.96 in Chennai, Rs 79.17 in Hyderabad, Rs 78.73 in Bengaluru and Rs 78.10 in Kolkata.

Diesel price per litre was hiked to Rs 74.62 in New Delhi, Rs 73.21 in Mumbai, Rs 72.69 in Chennai, Rs 72.93 in Hyderabad, Rs 70.95 in Bengaluru and Rs 70.33 in Kolkata.

Since 7 June, after ending their 82-day hiatus in daily revision, state-owned oil marketing companies have increased petrol price by Rs 5 per litre and diesel by Rs 5.23 per litre.

These prices are close to levels last seen in October-November 2018 when international oil prices had spiked close to $80 per barrel. In October 2018, petrol price in Mumbai had crossed Rs 90-mark and in Delhi, it was around Rs 83 per litre.

Comparatively, on Monday, Brent crude, the international benchmark for crude oil prices, fell 2.3 percent to $37.84 a barrel over concerns of subdued demand for fuel as new coronavirus infections were reported in China and the US.

The present spike in fuel prices in India could be attributed to the fact that central and state governments, along with oil marketing companies are looking to make up for their loss in revenues due to the lockdown.

Last month, the central government had increased the excise duty on per litre of petrol by Rs 10 and per litre of diesel by Rs 13. Several state governments have also hiked their VAT or cess on fuel in the last month. In fact, now around 70 percent of the retail price of fuel is just some form of tax.