12 killed as lorry ploughs into Berlin Xmas market

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.

New York, Jan 30: Three Indian citizens were arrested by border patrol agents here for entering the US illegally.

US Border Patrol agents stopped a vehicle near Massena in New York state along the county's northern border on January 24. During the vehicle checking, the agents found that two of the passengers were Indian citizens who entered the US illegally and not at a designated port of entry.

Both the passengers were transported to the Border Patrol Station for processing and charged.

The vehicle driver, also an Indian citizen who originally entered illegally into the US in 2012 and was ordered removed from the country in absentia last December, was charged with alien smuggling, a felony, which carries a penalty of a fine and up to five years of imprisonment for each violation.

Washington D.C, Jun 4: A lawsuit has been filed against US President Donald Trump for signing an executive order on preventing online censorship that seems to violate the freedom of speech of individuals on social media platforms.

On Tuesday, the Center for Democracy and Technology filed the lawsuit against Trump's "Executive Order on Preventing Online Censorship," which was signed May 28, 2020. The suit argues that the Executive Order violates the First Amendment by curtailing and chilling the constitutionally protected speech of online platforms and individuals.

"CDT filed suit today because the President's actions are a direct attack on the freedom of speech protected by the First Amendment. The government cannot and should not force online intermediaries into moderating speech according to the President's whims. Blocking this order is crucial for protecting freedom of speech and continuing important work to ensure the integrity of the 2020 election," said CDT President and CEO Alexandra Givens.

The executive order is designed to deter social media services from fighting misinformation, voter suppression, and the stoking of violence on their platforms, the digital rights group said.

"Access to accurate information about the voting process and the security of our elections infrastructure is the lifeblood of our democracy. The President has made clear that his goal is to use threats of retaliation and future regulation to intimidate intermediaries into changing how they moderate content, essentially ensuring that the dangers of voter suppression and disinformation will grow unchecked in an election year," Givens said.

The law firm of Mayer Brown is representing CDT in this action.