US confirms 1,069,534 coronavirus cases, death toll at 63,001

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 12: US President Donald Trump is considering suspending a number of employment visas including the H-1B, most sought-after among Indian IT professionals, in view of the massive unemployment in America due to the coronavirus pandemic, according to a media report.

The proposed suspension could extend into the government’s new fiscal year beginning October 1, when many new visas are issued, The Wall Street Journal reported on Thursday, quoting unnamed administration officials.

“That could bar any new H-1B holder outside the country from coming to work until the suspension is lifted, though visa holders already in the country are unlikely to be affected,” the daily reported.

H-1B is the most coveted foreign work visas for technology professionals from India.

Such a decision by the Trump administration is likely to have an adverse impact on thousands of Indian IT professionals. Already a large number of Indians on the H-1B visas have lost their jobs and are headed back home during the coronavirus pandemic.

The White House, however, said that no final decision has been made and the administration is considering various proposals.

“The administration is currently evaluating a wide range of options, formulated by career experts, to protect American workers and job seekers especially disadvantaged and underserved citizens — but no decisions of any kind have been made,” White House spokesman Hogan Gidley said in a statement.

In addition to the H-1B visas, the suspension could apply to the H-2B visa for short-term seasonal workers, the J-1 visa for short-term workers including camp counselors and au pairs and the L-1 visa for internal company transfers, the financial daily reported.

Meanwhile, the US Chambers of Commerce CEO Thomas Donohue on Thursday wrote a letter to Trump, expressing concern over his reported move on temporary work visas.

“As the economy rebounds, American businesses will need assurances that they can meet all their workforce needs. To that end, it is crucial that they have access to talent both domestically and from around the world,” Donohue wrote in a letter to Trump.

According to The Hill newspaper, Donohue said that American businesses need L-1 visa holders, who have a work visa valid for a relatively short amount of time, for necessary expertise.

He noted the importance of H-1B visa holders, who have a work visa valid for multiple years, for various industries, including technology, accounting and manufacturers, the newspaper said.

“Policies that would, for example, impose wide-ranging bans on the entry of nonimmigrant workers or impose burdensome new regulatory requirements on businesses that employ foreign nationals would undermine that access to talent and in the process, undercut our economy’s ability to grow and create jobs,” Donohue added.

The new visa regulations requiring international students in the US with an F-1 visa to take at least one in-person course or face the prospect of deportation is likely to "cause uncertainties and difficulties" for some students, the Indian Embassy has said.

"These new modifications at a time when many of the US universities and colleges are yet to announce their plans for the new academic year are likely to cause uncertainties and difficulties for some Indian students wishing to pursue their studies in the US," said a spokesperson of the Indian Embassy.

Responding to media queries, the spokesperson said the Indian government has taken up the matter with concerned US officials.

At the India US Foreign Office Consultations held on July 7, Foreign Secretary Harsh Vardhan Shringla conveyed India's concerns on the matter to Under Secretary of State for Political Affairs David Hale.

According to a recent report of Student and Exchange Visitor Program (SEVP), there were 1,94,556 Indian students enrolled in various academic institutions of the US in January this year. Of these 1,26,132 were males and 68,405 were females.

Noting that partnership in higher education is a key component of the strong people-to-people ties between India and the US, the spokesperson said in the last two decades Indian students in American universities and colleges have been the harbingers of a strong partnership between technology and innovation sectors between the two countries.

The spokesperson hoped that the US authorities would provide adequate flexibility in their visa rule, keeping in mind the extraordinary circumstances created by the COVID-19 pandemic for the Indian students community.

We continue to engage all the stakeholders in the matters, including the US administration officials, Congressional leaders, universities and colleges as well as the Indian students community in the US as we move forward towards the 2020-21 academic year to further strengthen our bilateral partnership in higher education, the spokesperson said.

Announced by the SEVP on July 6, the new rules provide temporary exemptions for nonimmigrant students on F-1 and M-1 visas taking online classes due to the COVID-19 pandemic for the fall semester of the 2020 academic year.

While these modifications do provide some flexibility for US universities and colleges to adopt a hybrid model -- that is a mixture of online and in person classes -- they also restrict international students on F-1 and M-1 visas from taking courses entirely online, the spokesperson said.