Godhra tragedy: Guj HC reduces death sentence of 11 to life term

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.

Bengaluru, Jun 19: COVID-19 cases in Karnataka has breached the 8,000 mark, as the state on Friday reported 337 new cases and ten related fatalities, taking the total number of infections to 8,281 and death toll to 124.

Also, total discharges in the state breached 5,000 mark, with 230 patients getting discharged in a day after recovery.

As of June 19 evening, cumulatively 8,281 COVID-19 positive cases have been confirmed in the state, which includes 124 deaths and 5,210 discharges, the health department said in its bulletin.

It said out of 2,943 active cases, 2,865 patients are in isolation at designated hospitals and are stable, while 78 are in ICU.

The ten dead include- seven from Bengaluru urban, two from Bidar and one from Vijayapura.

Out of the 337 new cases, 93 are returnees from other states, majority of them from neighboring Maharashtra,while 11 are those who returned from other countries.

The remaining cases include contacts of patients earlier tested positive, those with history of SARI and ILI, among others.

Among the districts where the new cases were reported, Bengaluru accounted for 138 cases, followed by Kalaburagi 52, Ballari 37, Hassan 18, Dakshina Kannada 13, Davangere 12, Udupi 11; Bidar 10, six each from Mysuru and Koppal, four each from Yadgir, Kolar and Bengaluru rural, three each from Mandya, Dharwad, Chikkaballapura, Bagalkote and Ramanagara, two each from Tumakuru and Chikkamagaluru, and one each from Belagavi, Uttara Kannada and Shivamogga.

Kalaburagi district tops the list of positive cases, with 1,126 infections, followed by Udupi 1,050 and Bengaluru urban 982.

Among discharges Udupi tops the list with 944 discharges, followed by Kalaburagi 646 and Yadgir 477.

A total of 4,84,060 samples were tested so far, out of which 10,553 were tested on Thursday alone.

According to the bulletin,4,64,338 samples have been reported as negative, and out of them 9,862 were reported negative today.

Bengaluru, Apr 28:  Karnataka Chief Minister B S Yediyurappa today launched a Helpline service for Kannadigas residing outside Karnataka.

On April 24, Dakshina Kannada district in-charge Minister Kota Srinivas Poojary in a letter to the Chief Minister requested a helpline for stranded Kannadigas in Mumbai, other States and other countries.

The helpline will help resolve the problem of stranded Kannadigas across the country. After a request is made, local authorities of the caller will be contacted to provide the required help. The helpline will be operated from Bengaluru and staffed with 50 employees in three shifts.