Twitter, Facebook accuse China of HK discord campaign

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, Jul 7: US Secretary of State Mike Pompeo on Monday (local time) confirmed that the White House is "looking at" banning the Chinese social media apps including TikTok.

"With respect to Chinese apps on people's cell phones, I can assure you the United States will get this one right too. I don't want to get out in front of the President [Donald Trump], but it's something we're looking at," Pompeo was quoted by CNN during an interview with Fox News.

He said people should only download the app, "if you want your private information in the hands of the Chinese Communist Party."

Responding to his comments, a TikTok spokesperson said, "TikTok is led by an American CEO, with hundreds of employees and key leaders across safety, security, product and public policy here in the US."

"We have no higher priority than promoting a safe and secure app experience for our users.  We have never provided user data to the Chinese government, nor would we do so if asked," the spokesperson added.

The US politicians have repeatedly criticised TikTok, owned by Beijing-based startup ByteDance, of being a threat to national security because of its ties to China.

Recently, India banned 59 Chinese apps including TikTok following a violent standoff with Chinese troops. This move was lauded by the US officials.

Jul 3: China under President Xi Jinping has stepped up its "aggressive" foreign policy toward India and "resisted" efforts to clarify the Line of Actual Control that prevented a lasting peace from being realised, according to a report released by a US Congress appointed commission.

The armies of India and China have been locked in a bitter standoff at multiple locations in eastern Ladakh for the last seven weeks, and the tension escalated after 20 Indian soldiers were killed in a violent clash in the Galwan Valley on June 15.

“Under General Secretary of the Chinese Communist Party (CCP) Xi Jinping, Beijing has stepped up its aggressive foreign policy toward New Delhi. Since 2013, China has engaged in five major altercations with India along the Line of Actual Control (LAC),” said a brief issued by US-China Economic and Security Review Commission.

"Beijing and New Delhi have signed a series of agreements and committed to confidence-building measures to stabilise their border, but China has resisted efforts to clarify the LAC, preventing a lasting peace from being realised,” said the report and was prepared at the request of the Commission to support its deliberations.

Authored by Will Green, a Policy Analyst on the Security and Foreign Affairs Team at the Commission, the report says that the Chinese government is particularly fearful of India’s growing relationship with the United States and its allies and partners.

“The latest border clash is part of a broader pattern in which Beijing seeks to warn New Delhi against aligning with Washington,” it said.

After Xi assumed power in 2012, there was a significant increase in clashes, despite the fact that he met Prime Minister Narendra Modi several times and Beijing and New Delhi have agreed to a series of confidence-building mechanisms designed to mitigate tensions.

Prior to 2013, the last major border clash was in 1987. The 1950s and 1960s were a particularly tense period, culminating in 1962 with a war that left thousands of soldiers dead on both sides, according to the records of China's People's Liberation Army, the report said.

“The 2020 skirmish is in line with Beijing’s increasingly assertive foreign policy. The clash came as Beijing was aggressively pressing its other expansive sovereignty claims in the Indo-Pacific region, such as over Taiwan and in the South and East China seas,” it said.

China is engaged in hotly contested territorial disputes in both the South China Sea and the East China Sea. Beijing has built up and militarised many of the islands and reefs it controls in the region. Both areas are stated to be rich in minerals, oil and other natural resources and are vital to global trade.

China claims almost all of the South China Sea. Vietnam, the Philippines, Malaysia, Brunei and Taiwan have counter claims over the area.

Several weeks before the clash in the Galwan Valley, Chinese Defence Minister Wei Fenghe called on Beijing to “use fighting to promote stability” as the country’s external security environment worsened, a potential indication of China’s intent to proactively initiate military tensions with its neighbours to project an image of strength, the report said.