Muslim women form human chain after Westminster terror attack

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.

Fifty-six journalists were killed in 2019 and most of them died outside conflict zones, a United Nations spokesperson said.

The number dropped by nearly half from the year 2018, but perpetrators enjoyed almost total impunity, Xinhua news agency quoted Stephane Dujarric, spokesperson for UN Secretary-General Antonio Guterres, as saying on Monday citing Unesco figures.

The figure was published in the 'Unesco Observatory of Killed Journalists' on Monday.

In total, Unesco recorded 894 journalist killings in the decade from 2010 to 2019, an average of almost 90 per year. The number in 2019 was 99.

Journalists were murdered in all regions of the world, with Latin America and the Caribbean recording 22 killings, the highest number, followed by 15 in Asia-Pacific, and 10 in Arab States.

"The figures show that journalists not only suffer extreme risks when covering violent conflict, but that they are also targeted when reporting on local politics, corruption and crime - often in their hometowns," the Unesco said.

Almost two thirds (61 per cent) of the cases in 2019 occurred in countries not experiencing armed conflict, a notable spike in a wider trend in recent years, and a reversal of the situation of 2014, when this figure was one third.

More than 90 per cent of cases recorded in 2019 concerned local journalists, consistent with previous years, it added.

In response to these figures, Audrey Azoulay, the Director-General of Unesco, said: "Unesco remains deeply troubled by the hostility and violence directed at all too many journalists around the world.

"As long as this situation lasts, it will undermine democratic debate."

Washington, Jun 2: There is no place for hate and racism in the society, Microsoft CEO Satya Nadella has said, asserting that empathy and shared understanding are a start, but more needs to be done. Nadella’s remarks come in the wake of the custodial death of George Floyd, a 46-year-old African-American man who was pinned to the ground in Minneapolis on May 25 by a white police officer who kneeled on his neck as he gasped for breath.

“There is no place for hate and racism in our society. Empathy and shared understanding are a start, but we must do more,” Nadella said in a tweet on Monday.

“I stand with the Black and African American community and we are committed to building on this work in our company and in our communities,” Nadella said.

A day earlier, Google CEO Sunder Pichai expressed solidarity with the African-American community.

“Today on US Google & YouTube homepages we share our support for racial equality in solidarity with the Black community and in memory of George Floyd, Breonna Taylor, Ahmaud Arbery & others who don’t have a voice,” Pichai wrote on Twitter on Sunday.

“For those feeling grief, anger, sadness & fear, you are not alone,” Pichai said, sharing a screenshot of the Google search home page which said, “We stand in support of racial equality, and all those who search for it.”

Nadella’s Microsoft also said they will be using the platform to amplify voices from the Black and African American community at the company.

Nadella had also spoken out a few months ago about the discriminatory Citizenship Amendment Act passed in his native country. Talking to BuzzFeed’s editor-in-chief, Ben Smith, in Manhattan, Nadella said what’s happening in the country is “sad.”

“I think what is happening is sad. I feel, and in fact quite frankly, now being informed (and) shaped by the two amazing American things that I’ve observed which is both, it’s technology reaching me where I was growing up and its immigration policy and even a story like mine being possible in a country like this.

“I think, it’s just bad, if anything, I would love to see a Bangladeshi immigrant who comes to India and creates the next unicorn in India or becomes the CEO of Infosys. That should be the aspiration. If I had to sort of mirror what happened to me in the US, I hope that’s what happens in India,” Microsoft’s India-born CEO was quoted as saying by BuzzFeed.