25 killed, deputy chairman Senate injured in blast in Pak

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.

Islamabad, Jun 24: A plane crash which killed 97 people in Pakistan last month was because of human error by the pilot and air traffic control, according to an initial report into the disaster released Wednesday.

The Pakistan International Airlines (PIA) plane came down among houses on May 22 after both engines failed as it approached Karachi airport, killing all but two people on board.

"The pilot as well as the controller didn't follow the standard rules," the country's aviation minister Ghulam Sarwar Khan said, announcing the findings in parliament.

He said the pilots had been discussing the coronavirus pandemic as they attempted to land the Airbus A320.

"The pilot and co-pilot were not focused and throughout the conversation was about coronavirus," Khan said.

The Pakistani investigation team, which included officials from the French government and the aviation industry, analysed data and voice recorders.

The minister said the plane was "100 percent fit for flying, there was no technical fault".

The county's deadliest aviation accident in eight years came days after domestic commercial flights resumed following a two-month coronavirus lockdown.

Many passengers were on their way to spend the Muslim holiday of Eid al-Fitr with loved ones.

Italian researchers have claimed that they have successfully developed a vaccine to contain coronavirus (COVID-19) which is likely to work on humans, a report said.

Luigi Aurisicchio, CEO of Takis, the firm developing the medication, said that a coronavirus candidate vaccine has neutralised the virus in human cells for the first time, the Arab News reported.

"This is the most advanced stage of testing of a candidate vaccine created in Italy. Human tests are expected after this summer," Aurisicchio was quoted as saying to Italian news agency ANSA.

"According to the Spallanzani Hospital, as far as we know we are the first in the world so far to have demonstrated neutralisation of the coronavirus by a vaccine. We expect this to happen in humans too," he added.

The researchers experimented with the vaccine on mice that had successfully developed antibodies that blocked the virus from infecting the cells. They further observed that the five vaccine candidates generated a large number of antibodies, and selected two with the best results.

All of the vaccine candidates currently being developed are based on the genetic material of DNA protein "spike", the molecular tip used by the coronavirus to enter human cells.

They are injected with the so-called "electroporation" technique, which consists of an intramuscular injection followed by a brief electrical impulse, helping the vaccine break into the cells and activating the immune system, the report said.

Researchers believe that this makes their vaccine particularly effective for generating functional antibodies against the "spike" protein, in particular in the lung cells, which are the most vulnerable to coronavirus.

"We are working hard for a vaccine coming from Italian research, with an all-Italian and innovative technology, tested in Italy and made available to everyone," Aurisicchio was quoted by the Arab News report.

"In order to reach this goal, we need the support of national and international institutions and partners who may help us speed up the process," he noted.

The total number of COVID-19 infections, fatalities and recoveries since the pandemic began has risen to 213,013 in the country.