56 journalists killed in 2019: UN

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.

Jun 23: US President Donald Trump has issued a proclamation to suspend issuing of H-1B visas, which is popular among Indian IT professionals, along with other foreign work visas for the rest of the year.

Trump said the step was essential to help millions of Americans who have lost their jobs due to the current economic crisis.

Issuing the proclamation ahead of the November presidential elections, Trump has ignored the mounting opposition to the order by various business organisations, lawmakers and human rights bodies.

The proclamation that comes into effect on June 24, is expected to impact a large number of Indian IT professionals and several American and Indian companies who were issued H-1B visas by the US government for the fiscal year 2021 beginning October 1.

They would now have to wait at least till the end of the current year before approaching the US diplomatic missions to get stamping. It would also impact a large number of Indian IT professionals who are seeking renewal of their H-1B visas.

“In the administration of our Nation's immigration system, we must remain mindful of the impact of foreign workers on the United States labour market, particularly in the current extraordinary environment of high domestic unemployment and depressed demand for labour,” said the proclamation issued by Trump.

In his proclamation, Trump said that the overall unemployment rate in the United States nearly quadrupled between February and May of 2020 -- producing some of the most extreme unemployment rates ever recorded by the Bureau of Labor Statistics.

While the May rate of 13.3 percent reflects a marked decline from April, millions of Americans remain out of work.

The proclamation also extends till the end of the year his previous executive order that had banned issuing of new green cards of lawful permanent residency.

Green card holders, once admitted pursuant to immigrant visas, are granted "open-market" employment authorisation documents, allowing them immediate eligibility to compete for almost any job, in any sector of the economy, he said.

“American workers compete against foreign nationals for jobs in every sector of our economy, including against millions of aliens who enter the United States to perform temporary work. Temporary workers are often accompanied by their spouses and children, many of whom also compete against American workers,” Trump said.

“Under ordinary circumstances, properly administered temporary worker programmes can provide benefits to the economy. But under the extraordinary circumstances of the economic contraction resulting from the COVID-19 outbreak, certain non-immigrant visa programmes authorising such employment pose an unusual threat to the employment of American workers,” he said.

For example, Trump said, between February and April of 2020, more than 17 million United States jobs were lost in industries in which employers are seeking to fill worker positions tied to H-2B nonimmigrant visas.

“During this same period, more than 20 million United States workers lost their jobs in key industries where employers are currently requesting H-1B and L workers to fill positions,” he said.

“Also, the May unemployment rate for young Americans, who compete with certain J non-immigrant visa applicants, has been particularly high -- 29.9 percent for 16-19-year-olds, and 23.2 percent for the 20-24-year-old group,” he said.

“The entry of additional workers through the H-1B, H-2B, J, and L non-immigrant visa programmes, therefore, presents a significant threat to employment opportunities for Americans affected by the extraordinary economic disruptions caused by the COVID-19 outbreak,” Trump said.

Trump observed that excess labour supply is particularly harmful to workers at the margin between employment and unemployment -- those who are typically "last in" during an economic expansion and "first out" during an economic contraction.

In recent years, these workers have been disproportionately represented by historically disadvantaged groups, including African Americans and other minorities, those without a college degree, and Americans with disabilities, he said.

The proclamation suspends and limits entry into the US of H-1B, H-2B and L visas and their dependents till December 31, 2020. It also includes certain categories of J visas like an intern, trainee, teacher, camp counselor, or summer work travel programme.

The new rule would apply only to those who are outside the US, do not have a valid non-immigrant visa and an official travel document other than a visa to enter the country.

According to the proclamation, it does not have an impact on lawful permanent residents of the United States and foreign nationals who are spouses or child of an American citizen.

Foreign nationals seeking to enter the US to provide temporary labour or services essential to the food supply chain are also exempted from the latest proclamation.

Islamabad, Jun 25: The coronavirus cases in Pakistan crossed the 192,000-mark after 4,044 new Covid-19 infections were detected in the last 24 hours, the health ministry said on Thursday.

According to the Ministry of National Health Services, 148 more people died due to the deadly virus in the country, taking the death toll to 3,903.

With the detection of 4,044 new cases in the last 24 hours, the coronavirus tally in the country now stands at 192,970, it said.

Sindh reported a maximum number of 74,070 infections, followed by 71,191 in Punjab, 23,887 in Khyber-Pakhtunkhwa, 11,710 in Islamabad, 9,817 in Balochistan, 1,365 in Gilgit-Baltistan and 930 in Pakistan-occupied Kashmir.

A total of 81,307 patients have recovered so far from the disease.

Health authorities have so far conducted 1,171,976 coronavirus tests, including 21,835 in the last 24 hours.