Bengaluru abattoir raid: What’s the truth behind attack on Nandini?

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.

Hassan, Jul 16: In fresh incident of cast killing, a Dalit youth in Alur taluk of Hassan district was shot dead yesterday by the relatives of the girl with whom he was in love. 

The deceased identified as Madhu, a 30-year-old resident of Soppinahalli village. He had taken a 25-year-old girl with him and was planning to marry her after taking her family into confidence.  

The relatives of the girl, who belong to upper caste, claimed that Madhu had kidnapped the daughter of one Ramesh of the same village. The girl's uncle Rupesh had waylaid Madhu when he was on the way to the field and shot at him. 

The body of the deceased as been shifted to a mortuary. The accused Rupesh has gone absconding. Sources said that the family of Ramesh has strongly opposed the inter-caste marriage.

Bengaluru, Feb 28: Historian S. Shettar, 85, breathed his last early on February 28 in Bengaluru. He was suffering from respiratory problems and was hospitalised for over a week.

Shettar was known for his multi-disciplinary work, encompassing linguistics, epigraphy, anthropology, the study of religions and art history. He had extensively worked on the Jain practice of ritual death in Karnataka and Asoka edicts. He had studied and compiled early edicts in Kannada and worked extensively on the growth of Kannada language down the ages.

Born in 1935 at Hampasagara, Ballari district, he went on to study at Cambridge University and started his career as a Professor of History at Karnatak University, Dharwad, his alma mater. He later headed the National Museum Institute of the History of Art, Conservation and Museology in 1978 and Indian Council for Historical Research in 1996. He was also a visiting professor at the National Institute of Advanced Studies, Bengaluru.

He was a bilingual historian who wrote in English for most of his career, but started writing in Kannada in later years. In the last two decades, he developed a keen interest in linguistics and wrote multiple books on classical Kannada and Prakrit. His 2007 book “Shangam Tamilagam” is considered a seminal work in the study of the early period of Dravidian languages. It won him Bhasha Samman from Central Sahitya Akademi. He later wrote two works on Halegannada, classical Kannada. His most recent work was “Prakrita Jagadvalaya” in 2018.