No evidence of terrorism in Las Vegas shooting, says FBI

Beijing, Apr 17: China denied Friday it had covered up the extent of its coronavirus outbreak, as it responded to growing questions from Western powers led by the United States.

A foreign ministry spokesman acknowledged that the virus's rapid spread had contributed to undercounting that resulted in China raising its death toll earlier Friday, but he added "there has never been any concealment, and we'll never allow any concealment."

The allegations China is too close to the World Health Organization (WHO), were an attempt at "smearing" Beijing, Zhao said.

US President Donald Trump has questioned China's handling of the pandemic and whether it had been completely transparent since the virus emerged in the central city of Wuhan late last year.

On Thursday, British Foreign Secretary Dominic Raab and French President Emmanuel Macron also expressed doubts about China's virus response.

These doubts were spotlighted again on Friday when authorities in Wuhan, which has borne the brunt of Chinese deaths, abruptly raised its death toll by 50 percent -- or 1,290 deaths -- to a new total of 3,869.

That also pushed the nationwide death toll up sharply to 4,632, based on official national data released earlier in the day.

Wuhan authorities cited several reasons for the missed cases, including that the city's medical staff were overwhelmed in the early days as infections climbed, leading to "late reporting, omissions or mis-reporting".

Zhao said such miscounting was to be expected in the initial stages of a major disease outbreak.

US President Donald Trump -- under fire himself for initially denying the seriousness of the pandemic -- has accused the WHO of doing the same and being too trusting of China's assurances over the outbreak.

On Tuesday he announced a suspension of US funding to the world body.

Asked about the US allegations, Zhao defended the WHO and China.

"I think they are all smearing China and cooking up stories about China," he said, without specifying which countries he was referring to.

China has largely brought the contagion under control domestically via tough measures including the unprecedented lockdown of Wuhan and tens of millions of people in surrounding areas, but not before it spread worldwide.

China is aggressively pursuing a diverse range of tactics -- from cyber-attacks to recruiting insiders for economic espionage, Indian security agencies have warned. The specific alert circulated among key stakeholders suggests that Chinese operatives are not only planning to steal classified cutting-edge defense technology but also eyeing to recruit best academicians and researchers around the globe, especially from the US.

Sources said they have noticed that China has authorized an "aggressive program of stealing US science and technology information by recruiting Americans in the technology sector with access to trade secrets".

In the technology sector of the US, many Indians scientists are working at the forefront. "This is a serious matter for Indian government and security establishments," said a top source further adding that Chinese always pursue economic espionage because it suits their low cost manufacturing sector on the basis of stolen research and costly design developed by top companies across the globe.

"An alert was also issued in early January about Chinese cyber intrusion attempts at several companies where Indian researchers are working. The espionage attempt was to target UAV technology and certain top-end military equipment designs. After stealing the techniques and design, China starts producing these equipment domestically and sells at a cheaper rate, inflicting irreparable damage to the original equipment manufacturers," the sources in the security establishment observed.

Recently, the US accused China for targeting academia by sending researchers to American labs and using talent recruitment programme to steal scientific analysis. The US has also found that young recruits of the People's Liberation Army posing as students are entering into various universities across the globe to get research papers and recruit academia.

Earlier this year, the US charged a former Boston University student of visa fraud for failing to disclose the status as a lieutenant in the China's People's Liberation Army.

The US intelligence agencies have found that their "universities have become a soft target in the global espionage war with China".

In January this year, the US Department of Justice charged a leading academician at the Harvard University for hiding his alleged role in a Chinese government programme.

In July last year, the Federal Bureau of Investigation (FBI) Director Christopher Wray had revealed that the FBI is probing nearly 1,000 cases of economic espionage and attempted intellectual property theft, nearly all of them leading back to China.

Accordingly, Indian Missions have been informed about the threats being posed by Chinese spies and attempts to recruit Indian scientists and technologists working in the US and other parts of the world.

Sources further stated that security establishments in India have informed the scientist fraternity to be on alert amid threat posed by Chinese spies.

The Chinese had earlier recruited a personnel, Dongfan Chung, working at Boeing for economic espionage. Chung had stolen secret technology to benefit Chinese government and during the raid at his house more than 2.5 lakh classified pages related to Boeing were recovered.

"There has been intense debate on the international platforms regarding Chinese-sponsored theft of intellectual property. American agencies have gone on record to say that China was targeting trade secrets. In the backdrop of pandemic and global health crisis, Indian establishments in defence and technology sectors have been told to be extra cautious as China is planning to become the most advanced economy while the other countries are crippled by the highly contagious virus," the sources further added.

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.