Pak Bans 1st Class Air Travel By Leaders, Officials, Work Hours Revised

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, Jun 17: The United States is closely monitoring the situation following a fierce clash between Indian and Chinese forces in eastern Ladakh and hopes that the differences will be resolved peacefully, officials said here.

Twenty Indian Army personnel including a colonel were killed in the clash with Chinese troops in the Galwan Valley in eastern Ladakh on Monday night, the biggest military confrontation in over five decades that has significantly escalated the already volatile border standoff in the region.

"We are closely monitoring the situation between Indian and Chinese forces along the Line of Actual Control," a State Department spokesperson said.

"We note the Indian military has announced that 20 soldiers have died, and we offer our condolences to their families," the official said.

Both India and China have expressed their desires to de-escalate and the US supports a peaceful resolution of the current situation, the spokesperson said.

"During their phone call on June 2, 2020, President Donald Trump and Prime Minister Narendra Modi had discussed the situation along the India-China border," the official added.

Kabul, Jun 12: A blast in a mosque during Friday prayers in the western part of capital Kabul has killed at least four people and wounded many more, Afghanistan's interior ministry said.

"Explosives placed inside the Sher Shah Suri Mosque exploded during Friday prayers," said a statement issued by the ministry, which added that the mosque's prayer leader Mofleh Frotan was among those killed.

Interior ministry spokesman Tariq Arian said police have cordoned off the area and helped move the wounded to ambulances and nearby hospitals.

No group immediately claimed responsibility for the attack but a mosque attack earlier this month was claimed by an ISIL (or ISIS) group affiliate, headquartered in eastern Afghanistan's Nangarhar province.

"Interestingly, every time you have the peace process gaining some momentum and pace, you have these kinds of attacks in the country," Habib Wardak, a national security analyst based in Kabul, told Al Jazeera.

"The Islamic State group claimed responsibility for the attack that happened last week on a mosque in Kabul, so despite the fact that you have these news and press conference from the government that they have eliminated ISIL, how can they conduct such sophisticated operations?"

Friday's blast had parallels to one earlier this month, when an explosion tore apart a famous Kabul mosque and led to the death of renowned Afghan cleric Maulvi Ayaz Niazi.

"In this attack, the imam seems to be the target, not the rest of the crowd. These are the imams who have supported the peace process with the Taliban movement," Wardak said.

"The other political aspect for these kinds of attacks is that there are peace spoilers trying to convey a message that peace with the Taliban will not eradicate violence in the country because you have ISIL."

Violence has spiked in recent weeks in Afghanistan with most of the attacks claimed by the ISIL affiliate.

The United States blamed the armed group for a horrific attack last month on a maternity hospital in the capital that killed 24 people, including two infants and several new mothers.

The ISIL affiliate also took responsibility for an attack on a bus carrying journalists in Kabul on May 30, killing two.

It also claimed credit for an attack on the funeral of a strongman loyal to the government last month that killed 35 people.

Meanwhile, the US is attempting to broker peace talks between the Afghan government and the Taliban to end 18 years of war.

Washington's peace envoy Zalmay Khalilzad was in the region earlier this week trying to resuscitate a US peace deal with the Taliban.

The peace deal signed in February calls for the withdrawal of the US and NATO troops from Afghanistan in return for a commitment by the Taliban to not launch attacks on the US or its allies.