51 children, three teachers hurt in chemical attack on kindergarten in China

Beijing, Jun 11: Floods and mudslides in south China have uprooted hundreds of thousands of people and left dozens dead or missing, state media reported Thursday.

The bad weather has wreaked havoc on popular tourist areas that had already been battered by months of travel restrictions during the coronavirus outbreak.

Torrential downpours unleashed floods and mudslides that caused nearly 230,000 people to be relocated and destroyed more than 1,300 houses, official state news agency Xinhua reported, citing the Ministry of Emergency Management.

In southern Guangxi Zhuang Autonomous Region, six people were reported dead and one missing, Xinhua said.

Streets were waterlogged in popular tourist destination Yangshuo, forcing residents and visitors to evacuate on bamboo rafts.

The local government said more than 1,000 hotels had been flooded and more than 30 tourist sites damaged.

One owner of a family-run hotel told Xinhua that the guest rooms were submerged in one metre (three feet) of rainwater.

The extreme weather has dealt a hefty blow to the region's tourism sector, which is still reeling from the COVID-19 epidemic.

The emergency management ministry said there were direct economic losses of over 4 billion yuan (more than $550 million) from the flooding, Xinhua reported.

In Hunan Province, at least 13 people were killed in rain-triggered disasters, and another eight people are missing or killed in southwestern Guizhou province, according to the local emergency response departments, Xinhua said.

The heavy downpours began at the beginning of June and have led to "dangerously high water levels" in 110 rivers, Xinhua reported.

Further rainstorms are expected in the next few days across the south.

Sydney, Jan 8:  Authorities in Australia will begin five-day campaign to kill thousands of camels in the country as they drink too much water amid the wildfires.  The government will send helicopters to kill up to 10,000 camels in a five-day campaign starting Wednesday, The Hill reported citing The Australian.

Marita Baker, an Anangu Pitjantjatjara Yankunytjatjara (APY) (large, sparsely-populated local government area for Aboriginal Australians) executive board member, said that the camels were causing problems in her community of Kanypi.

"We have been stuck in stinking hot and uncomfortable conditions, feeling unwell, because the camels are coming in and knocking down fences, getting in around the houses and trying to get to water through air conditioners,'' she said.

The planned killing of the camels comes at a time the country is ravaged by wildfires since November. The disaster has killed more than a dozen people and caused the displacement or deaths of 480 million animals, according to University of Sydney researchers.

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.