Zardari rules out any unilateral withdrawal from Siachen

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.

Naypyitaw, Jul 2: A landslide at a jade mine in northern Myanmar has killed at least 113 people, officials say, warning the death toll is likely to rise further.

The incident took place early on Thursday in the jade-rich Hpakant area of Kachin state after a bout of heavy rainfall, the Myanmar Fire Services Department said on Facebook.

"The jade miners were smothered by a wave of mud," the statement said. "A total of 113 bodies have been found so far," it added, raising the death toll from at least 50.

Photos posted on the Facebook page showed a search and rescue team wading through a valley apparently flooded by the mudslide.

'No one could help them'

Maung Khaing, a 38-year-old miner from the area, said he saw a towering pile of waste that looked on the verge of collapse and was about to take a picture when people began shouting "run, run!"

"Within a minute, all the people at the bottom [of the hill] just disappeared," he told Reuters news agency by phone.

"I feel empty in my heart. I still have goosebumps ... There were people stuck in the mud shouting for help, but no one could help them."

Tar Lin Maung, a local official with the information ministry, said authorities had recovered more than 100 bodies.

"Other bodies are in the mud. The numbers are going to rise," he told Reuters.

Fatal landslides are common in the poorly regulated mines of Hpakant, the victims often from impoverished communities who risk their lives hunting the translucent green gemstone.

The government of Myanmar leader Aung San Suu Kyi pledged to clean up the industry when it took power in 2016, but activists say little has changed.

Official sales of jade in Myanmar were worth $750.4m in 2016-2017, according to data published by the government as part of the Extractive Industries Transparency Initiative.

But experts believe the true value of the industry, which mainly exports to China, is much larger.

Northern Myanmar's abundant natural resources - including jade, timber, gold and amber - have also helped finance both sides of a decades-long conflict between ethnic Kachin and the military.

The fight to control the mines and the revenues they bring frequently traps local civilians in the middle.

Beijing, June 30: China said on Tuesday it was concerned about India’s decision to ban Chinese mobile apps such as Bytedance’s TikTok and Tencent’s WeChat and was making checks to verify the situation.

Chinese foreign ministry spokesman Zhao Lijian told reporters during a daily briefing that (the Prime Minister Narendra Modi-led government of) India has a responsibility to uphold the rights of Chinese businesses.

India on Monday banned 59, mostly Chinese, mobile apps in its strongest move yet targeting China in the online space since a border crisis erupted between the two countries this month.

The apps are “prejudicial to the sovereignty and integrity of India, the defence of India, the security of state and public order", the ministry of information technology said in a statement, which came two weeks after 20 Indian Army personnel were killed in a violent clash on the India-China border in Ladakh.

The companies have been invited to offer clarifications before a government panel, which will decide whether the ban can be removed or will stay.

The move also came ahead of military and diplomatic talks between India and China scheduled this week.