US lost eight jets in worst air loss in one day since Vietnam war

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.

Jan 30: The death toll rose to 170 in the new virus outbreak in China on Thursday as foreign evacuees from the worst-hit region begin returning home under close observation and world health officials expressed “great concern” that the disease is starting to spread between people outside of China.

Thursday’s figures cover the previous 24 hours and represent an increase of 38 deaths and 1,737 cases for a total of 7,711. Of the new deaths, 37 were in the epicenter of the outbreak in Hubei province and one in the southwestern province of Sichuan.

The news comes as the 195 Americans evacuated from Wuhan, the Hubei province city of 11 million where the outbreak originated, are undergoing three days of testing and monitoring at a Southern California military base to make sure they do not show signs of the virus.

A group of 210 Japanese evacuees from Wuhan landed Thursday at Tokyo’s Haneda airport on a second government chartered flight, according to the foreign ministry. Reports said nine of those aboard the flight showed signs of cough and fever. Three of the 206 Japanese who returned on Wednesday tested positive for the new coronavirus, Prime Minister Shinzo Abe said during a parliamentary session. Two of them showed no symptoms of the disease.

France, New Zealand, Australia and other countries are also pulling out their citizens or making plans to do so.

The World Health Organization emergencies chief said the few cases of human-to-human spread of the virus outside China — in Japan, Germany, Canada and Vietnam — were of “great concern” and were part of the reason the U.N. health agency’s director-general was reconvening a committee of experts on Thursday to assess whether the outbreak should be declared a global emergency.

The new virus has now infected more people in China than were sickened there during the 2002-2003 SARS outbreak.

Dr. Michael Ryan spoke at a news conference in Geneva on Wednesday after returning from a trip to Beijing to meet with Chinese President Xi Jinping and other senior government leaders. He said China was taking “extraordinary measures in the face of an extraordinary challenge” posed by the outbreak.

To date, about 99% of the cases are in China. Ryan estimated the death rate of the new virus at 2%, but said the figure was very preliminary. With fluctuating numbers of cases and deaths, scientists are only able to produce a rough estimate of the fatality rate and it’s likely many milder cases of the virus are being missed.

In comparison, the SARS virus killed about 10% of people who caught it. The new virus is from the coronavirus family, which includes those that can cause the common cold as well as more serious illnesses such as SARS and MERS.

Scientists say there are many questions to be answered about the new virus, including just how easily it spreads and how severe it is.

In a report published Wednesday, Chinese researchers suggested that person-to-person spread among close contacts occurred as early as mid-December.

“Considerable efforts” will be needed to control the spread if this ratio holds up elsewhere, researchers wrote in the report, published in the New England Journal of Medicine.

More than half of the cases in which symptoms began before Jan. 1 were tied to a seafood market, but only 8% of cases after that have been, researchers found. They reported the average incubation period was five days.

Washington, Jun 18: US Defence officials are concerned over China's use of COVID-19 situation to gain stakes in strategically important companies of United States as the impact of novel coronavirus has left several companies in dire need of capital.

Amid the pandemic, it getting hard for the defence department to keep an eye on national security and help protect smaller companies down the chain, CNN reported.

"We are paying close attention to any indicators that China is leveraging Covid-19 to take advantage of a situation where defence companies need capital more than ever," a defence official told CNN.

In April, Ellen Lord, undersecretary of defence for acquisition and sustainment said it is paying close attention to 'adversaries' against the 'economic warfare' with the United States.

"We have to be very, very careful about the focused efforts some of our adversaries have to really undergo sort of economic warfare with us, which has been going on for some time," Ellen Lord, undersecretary of defence for acquisition and sustainment was quoted as saying by CNN.

US Committee on Foreign Investment protects its interest against hostile countries gaining ownership in strategically important companies. But the pandemic is changing the definition of national security concerns to include drugs, protective gear and medical supplies.

"These are now national security needs and we probably should have been thinking about it a long time ago in terms of biowarfare that we should have a trusted industrial base or a set of trusted allies -- the UK, or NATO allies or Japan or Korea -- who are trusted in that regard," Bill Greenwalt, a former Pentagon official.

Give the threat posed by foreign acquisition, Pentagon has been offering tools to help small US businesses defend themselves against adversarial investment and conducting background checks with other government agencies to ensure transparency.

US President Donald Trump's trade adviser Peter Navarro recently told CNN if Trump wins reelection, Washington DC will likely take offshore supply chains as national security priorities.

"If we fail to do that in the face of this crisis, we will have failed this country and all future generations of Americans," Navarro said.

The US State Department has also warned US allies to "avoid economic overreliance on China" and "guard their critical infrastructure" from China's influence.

Chad P Bown, a senior fellow at the Peterson Institute for International Economics, pointed to recent China's economic coercion of Australia on the political matter saying, "this is how China operates and everybody knows it."