Former minister, statesman B A Mohideen no more

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.

Mangaluru, May 23: In order to ensure that students do not miss out on their studies due to educational institutions being shut owing to the coronavirus lockdown, Dakshina Kannada Pre-university College Principles Association (DKPUCPA) is conducting online classes on YouTube for pre-university students.

The online lessons are shot by lecturers at St Aloysius College and the lectures are then uploaded on YouTube enabling students to watch them online.

"The whole world is currently in a crucial situation because of COVID-19, and because of the lockdown, all are forced to stay indoors. Usually, we used to conduct lectures in a class full of students, but now it is a new experience that we are providing the same information to students in their absence," Rajaram Rao, a lecturer said while speaking to news agency.

He said at present these classes are being conducted for second year pre-university students.

If any student has a doubt on any concept, he said they can contact the teachers. "At present, students also are getting information about the teachers who have uploaded the videos. All the information about the teachers is already being uploaded on the system so that they can contact the teacher," he said.

Dhanya, a student, hailed the DKPUCPA for the setting up of the online classes despite the prevailing situation.

"The teachers who have taught in these classes have taught very well, as if they are teaching right in front of us. It has been very useful for me during this time," she said.

The nationwide lockdown imposed to combat the threat posed by the coronavirus pandemic has been extended to May 31.

Mangaluru, Mar 14: Following the avian flu outbreak in neighboring Kerala, authorities at Pilikula Biological Park in Moodushedde, on the outskirts of the city, have taken all precautionary measures to prevent the death of birds in the park.

Park Director H J Jayaprakash Bhandari said that "the behaviour of the birds is being monitored near open water sources on the premises'.

Though no deaths were reported in the Zoo or on lake premises, the staff continue to maintain a strict vigil on open water sources like lakes. He said the Park was being sanitized.