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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.

Jun 2: A new female billionaire has emerged from one of Asia's most-expensive breakups.

Du Weimin, the chairman of Shenzhen Kangtai Biological Products Co., transferred 161.3 million shares of the vaccine maker to his ex-wife, Yuan Liping, according to a May 29 filing, immediately catapulting her into the ranks of the world's richest.

The stock was worth $3.2 billion as of Monday's close.

Yuan, 49 this year, owns the shares directly, but signed an agreement delegating the voting rights to her ex-husband, the filing shows. The Canadian citizen, who resides in Shenzhen, served as a director of Kangtai between May 2011 and August 2018. She's now the vice general manager of subsidiary Beijing Minhai Biotechnology Co. Yuan holds a bachelor's degree in economics from Beijing's University of International Business and Economics.

Kangtai shares have more than doubled in the past year and have continued their ascent since February, when the company announced a plan to develop a vaccine to fight the coronavirus. They slipped for a second day Tuesday following news of the divorce terms, losing 3.1% as of 9:43 a.m. in Hong Kong and bringing the company's market value to $12.9 billion.

Du's net worth has now dropped to about $3.1 billion from $6.5 billion before the split, excluding his pledged shares.

The 56-year-old was born into a farming family in China's Jiangxi province. After studying chemistry in college, he began working in a clinic in 1987 and became a sales manager for a biotech company in 1995, according to the prospectus of Kangtai's 2017 initial public offering. In 2009, Kangtai acquired Minhai, the company Du founded in 2004, and he became the chairman of the combined entity.

China's rapidly growing economy has been an engine for the country's richest, and Du is not the only tycoon who's had to pay a steep price for a divorce. In 2012, Wu Yajun, at one point the nation's richest woman, transferred a stake worth about $2.3 billion to her ex-husband, Cai Kui, who co-founded developer Longfor Group Holdings Ltd. In 2016, tech billionaire Zhou Yahui gave $1.1 billion of shares in his online gaming company, Beijing Kunlun Tech Co., to ex-wife Li Qiong after a civil court settlement.

Sometimes, a goodbye can be time-consuming too. South Korean tycoon Chey Tae-won's wife filed a lawsuit in December asking for a 42.3% stake in SK Holdings Co. valued at $1.2 billion. That would make her the second-largest shareholder of the company should she win the case, which is still ongoing.

The most expensive divorce in history is that of Jeff and MacKenzie Bezos. The Amazon.com Inc. founder gave 4% of the online retailer to Mackenzie, who now has a $48 billion fortune and is the world's fourth-richest woman.

Jan 15: Uttar Pradesh Chief Minister Yogi Adityanath said on Tuesday that the Muslim population in India increased manifold since the partition because they were given special rights and facilities, according to a report by The Indian Express.

"The Muslim population in India has increased manifold since 1947, it has gone up by seven to eight times. No one has any objection. If they, as citizens of the country, work for development, they are welcome. Their population has increased because they have been given special rights and facilities. All possible steps were taken to ensure their growth," Adityanath said while addressing a rally in Gaya organised by the BJP in support of the Citizenship (Amendment) Act.

He asked the audience, "But what happened in Pakistan?" Claiming that the Hindu population in Pakistan had decreased since 1947, he asked why it was so.

Yogi said that the countrywide anti-CAA protests are a "conspiracy" hatched from afar by those resentful of a united and grand India and these are being aided by a "crooked" opposition. He further charged that those opposing the legislation were committing the "paap" (sin) of working against national interests.

"For taking such a step, Prime Minister Narendra Modi and Home Minister Amit Shah deserve acclaim. Instead, they are being attacked", Yogi lamented.