Trump praises Chinese president Xi Jinping extending tenure 'for life'

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.

Washington, Mar 1: The US Federal Communications Commission (FCC) has proposed a fine of over $200 million for all major US mobile carriers for selling the location data of customers to some agencies.

The Federal Communications Commission today proposed fines against the nation's four largest wireless carriers for apparently selling access to their customers' location information without taking reasonable measures to protect against unauthorised access to that information. As a result, T-Mobile faces a proposed fine of more than $91 million, AT&T faces a proposed fine of more than $57 million, Verizon faces a proposed fine of more than $48 million, and Sprint faces a proposed fine of more than $12 million, the FCC said in a statement on Friday.

The Enforcement Bureau of FCC opened this investigation after reports surfaced that a Missouri Sheriff, Cory Hutcheson, used a "location-finding service" operated by Securus, a provider of communications services to correctional facilities, to access the location information of the wireless carriers' customers without their consent between 2014 and 2017.

"American consumers take their wireless phones with them wherever they go. And information about a wireless customer's location is highly personal and sensitive. The FCC has long had clear rules on the books requiring all phone companies to protect their customers' personal information. And since 2007, these companies have been on notice that they must take reasonable precautions to safeguard this data and that the FCC will take strong enforcement action if they don't. Today, we do just that," said FCC Chairman Ajit Pai.

"This FCC will not tolerate phone companies putting Americans' privacy at risk."

The FCC also admonished these carriers for apparently disclosing their customers' location information, without their authorisation, to a third party

The four major US carriers mentioned sold access to their customers' location information to "aggregators," who then resold access to such information to third-party location-based service providers (like Securus).

Although their exact practices varied, each carrier relied heavily on contract-based assurances that the location-based services providers (acting on the carriers' behalf) would obtain consent from the wireless carrier's customer before accessing that customer's location information.