France's COVID-19 deaths nearing 18,000, cases tally over 108,000

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.

Kathmandu, June 18: Nepal's National Assembly on Thursday unanimously passed the Constitution Amendment Bill to update the country's political and administrative map incorporating three Indian territories. 

The new map also includes land controlled by India. It requires President Bidhya Devi Bhandari's approval.

India, which controls the region - a slice of land including Limpiyadhura, Lipulekh and Kalapani areas in the northwest - has rejected the map, saying it is not based on historical facts or evidence.

India has termed as untenable the "artificial enlargement" of territorial claims by Nepal after its lower house of parliament on Saturday unanimously approved the new political map of the country featuring areas which India maintains belong to it.

The National Assembly, or the upper house of the Nepalese parliament, unanimously passed the constitution amendment bill providing for inclusion of the country's new political map in its national emblem.

The bill was passed with all the 57 members present voting in its favour.

The dispute

The latest border dispute between the countries began last month after India inaugurated Himalayan link road built in a disputed region that lies at a strategic three-way junction with Tibet and China.

The 80km (50-mile) road, inaugurated by Indian Defence Minister Rajnath Singh, cuts through the Lipulekh Himalayan pass, considered one of the shortest and most feasible trade routes between India and China.

The road cuts the travel time and distance from India to Tibet's Mansarovar lake, considered holy by the Hindus.

But Nepal says about 19km of the road passes through its area and fiercely contested the inauguration of the road, viewing the alleged incursion as a stark example of bullying by its much larger neighbour.

Nepal, which was never under colonial rule, has long claimed the areas of Limpiyadhura, Kalapani and Lipulekh under the 1816 Sugauli treaty with the British East India Company, although these areas have remained under the control of Indian troops since India fought a war with China in 1962.

Geneva, Jul 2: The World Health Organization (WHO) has estimated the overall number of coronavirus cases globally at 10,357,662, with 508,055 people having died from the disease.

The UN health agency said in the situation report published on late Wednesday that 163,939 new cases had been recorded in the past day, while further 4,188 patients had died.

Americas continue to lead the count with over 5.2 million cases, followed by Europe with more than 2.7 million.

The WHO declared the COVID-19 outbreak a pandemic on March 11.