Iraq presses counter-offensive, ISIL declares 'caliphate'

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 6: US President Donald Trump has said that countries like India and China would have much more coronavirus cases than America, the worst-hit country in the world, if they conduct more tests.

Trump, in his remarks at Puritan Medical Products in Maine, said that the US has carried out 20 million tests.

Compared to the US, Germany is at four million and much talked about South Korea is about three million tests, he said on Friday.

According to Johns Hopkins Coronavirus Resource Center, the US has reported nearly 1.9 million cases and over 1,09,000 deaths, making America the worst affected country, while the total number of coronavirus cases in India and China stand at 2,36,184 and 84,177 respectively.

India has so far conducted over 4 million coronavirus tests, according to the health ministry.

Commenting on the COVID-19 tests in the US, Trump said: "We will be well over 20 million tests. Remember this, when you test more, you have more cases.

"I say to my people every time we test; you find cases because we do more testing. If we have more cases, if we wanted to do testing in China or in India or other places, I promise you there would be more cases... you are doing a fantastic job in getting out the swabs".

Puritan is one of the only manufacturers in the world producing the high-quality medical swabs that are crucial for rapid testing.

"And every swab you make at Puritan is proudly stamped with the beautiful phrase made in the USA."

"Thanks to the testing capacity that you are making possible, our country is reopening and our economy is recovering like nobody would've thought possible," he said.

Referring to the latest monthly employment numbers, Trump said that the economy is now back on track.

"We absolutely shattered expectations, and this is the largest monthly jobs increase in American history, think of that; that's a long time.

"I think it's more than double or about double of what our highest was before so this is the largest monthly job increase in American history. And we're going to have a phenomenal next year. We're going to have a tremendous couple of months prior to the election on November 3 very, very important date," the president said.

Seeking re-election for his second consecutive term, Trump is pitted against Democratic presidential nominee Joe Biden in November 3 presidential elections. Most of the opinion polls shows that Biden is several points ahead of Trump.

"It's going to be a very important election because the only thing that can screw it up is if you get the wrong president and they raise your taxes, and they open up your borders so that everybody pours into our country," Trump said.

Reiterating that he has built a strong economy in the last three years, Trump vowed to bring the economy back on track, which has been badly hit by the coronavirus pandemic.

Describing the fight against coronavirus as the greatest national and industrial mobilisation since the World War II, Trump said that his administration has marshaled the full power of the US government and US industry to defeat the invisible enemy.

"It is indeed an enemy. It came from China, should have been stopped in China. They didn't do that," he alleged.

The administration, he said, has delivered over 1.5 billion pieces of personal protective equipment to doctors and nurses on the front lines. "We slashed the red tape to speed up the development of vaccines. And vaccines are coming along incredibly well, wait till you see, and therapeutics. And we partnered at private sector leaders such as Puritan to build the largest and most advanced testing capacity on the face of the earth, like this one," he said.

The Puritan factory in Maine, he said, quickly ramped up the production to produce nearly 20 million foam tipped swabs each month.

"Then in April, my administration invoked the Defence Production Act to help you scale up even more. Under a USD 75 million public-private partnership, Puritan will soon double production to 40 million swabs per month," Trump added.

Washington, Jul 14: The United States has the biggest Covid-19 testing programme in the world, better than big countries like Russia, China, India and Brazil, President Donald Trump said on Monday, asserting that America has "just about the lowest mortality rate" due to the disease in the world.

"We have one of the lowest mortality rates anywhere," Trump said at a White House roundtable. More than 34 lakh Americans have tested positive for Covid-19 so far and over 1,37,000 have died due to the disease, both of which are the largest numbers among all the countries.

The huge number of positive cases, the president said, is due to the massive testing efforts undertaken by his administration, more extensive than any other country.

"We test more than anybody by far. And when you test, you create cases. So we have created cases. I can tell you that some countries, they test when somebody walks into a hospital sick or walks into maybe a doctor's office, but usually a hospital. That is the testing they do, so they do not have cases, whereas we have all these cases. So, it is a double-edged sword," he said.

At the same time, the United States has the lowest mortality rate or just about the lowest mortality rate due to the disease in the world, Trump added. "We are doing a great job. We are doing very well with vaccines and we are doing very, very well with therapeutics. I think we are going to have some very good information coming out soon," he said in response to a question.

"But we have the best and certainly, by far, the biggest testing programme anywhere in the world. If you tested China or Russia or any of the larger countries, if you just tested India, as an example, the way we test, you would see numbers that would be very surprising. Brazil too. You know, Brazil is going through a big problem, but they do not do testing like we do," Trump said.

"So we do the testing and by doing the testing, we have tremendous numbers of cases. As an example, we have done 45 million tests. If we did half that number, you would have half the cases probably -- around that number. If we did another half of that, you would have half the numbers. Everyone would be saying, 'Oh, we are doing so well on cases'," he added.

Responding to a question, Trump said what China did to the world should not be forgotten.

"I think what China has done to the world with what took place -- the China plague -- you can call it the China virus, you can call it whatever you want to call it. It has about 20 different names. What they did to the world should not be forgotten," he said.

The trade deal with China that was signed early this year remains intact, the president said. "It is intact, they (China) are buying. Whether they buy or not, that is up to them. They are buying," he said.