India 'misleading the public' on Sikkim stand-off, says China

Bueno Aires, Apr 25: Dozens of prisoners at a jail in Argentina's capital Buenos Aires rioted on Friday demanding urgent health measures after confirmation of a coronavirus case inside the facility.

Police surrounded the prison, which holds around 2,200 inmates, as explosions were heard, news agency reporters at the scene said.

A group of prisoners managed to climb onto a roof, burn mattresses and throw objects at security guards trying to quell the uprising.

Authorities have yet to comment on the riot or whether there are any injuries.

Inmates could be heard shouting demands for a judge to hear their case and for better protection against the pandemic, just a few days after a warden at the Villa Devoto prison was confirmed to have contracted the novel coronavirus.

"COVID-19 in Devoto, genocidal judges," read a banner hung from the prison roof. "We refuse to die in prison," read another.

The inmates are demanding, among other things, that releases that were pending before the pandemic be processed.

Several other riots broke out in prisons last week, including in Florencio Varela in Buenos Aires province where one inmate died and 20 were injured.

Argentina has been in lockdown since March 20 and has recorded more than 3,400 coronavirus cases and 167 deaths.

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.

Kabul, May 11: Four back-to-back roadside bombs exploded in a northern district of Afghanistan's capital Kabul on Monday, wounding four civilians including a child, police said. Kabul police spokesman Ferdaws Faramarz said a clearance team was at the site of the attacks.

Militants have carried out several roadside bombings and rocket attacks in Kabul and other parts of the country in recent weeks, but Monday's four consecutive explosions appeared to be the first coordinated effort for some months.

The Taliban has not carried out any large attacks in the city since they signed a landmark withdrawal deal with the US in February, meant to pave the way for peace in the country. No group has claimed the attacks. The explosions come as authorities are trying to impose a lockdown in the capital to curb the spread of coronavirus in the country.