Anti-racism protests continue across the world

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.

Canberra, May 21: Australian Prime Minister Scott Morrison and his Indian counterpart, Narendra Modi, are looking forward to deepening the countries' strategic relationship, with both sides expected to sign a range of pacts from defence to trade in strategic sectors amid heightened tensions with China over Beijing's response to coronavirus pandemic.

During a virtual summit, scheduled to take place on June 4, both leaders are expected to ramp up efforts to diversify Australia's export markets and find trusted suppliers of vital products and components, a local newspaper, The Australian reported on Tuesday.

The new agreements will focus on reliable supply chains in key strategic sectors, including medical goods, technology and critical minerals, amid heightened tensions with China over Beijing's response to coronavirus pandemic.

The leaders will seal a new defence agreement allowing reciprocal access to bases and co-operation on military technology projects, while a new education partnership will be on the table to help overcome Australian university reliance on Chinese students.

The talks in terms of strategic convergence, now have greater significance as COVID-19 exacerbates the strategic contest between the US and China, and forces like-minded countries to seek out reliable partners.

Australian farmers could also benefit, with talks underway on expanding agricultural exports to India, including barley, as China throws up new trade barriers, media reports stated.

The virtual summit follows the cancellation of Morrison's planned state visit to India in January due to the bushfires.

Morrison said last year, ahead of his planned visit, that India was "a natural partner for Australia", referring to the countries' "shared values" -- a point of differentiation with China.

Former Department of Foreign Affairs and Trade secretary Peter Varghese, who wrote a landmark report on the bilateral relationship in 2018, was quoted by the newspaper as saying that India would be even more important to Australia in the post-COVID world. "If one of the lessons from COVID is that countries need to spread their risk, then finding new markets or building up existing markets is a crucial part of that," he added.

Varghese noted that India, a member of the Quadrilateral Security Dialogue along with Australia, Japan and the US, was a vital strategic partner to Australia in helping "constrain China's ambitions to be the predominant power".

"That shared objective between Australia and India of not wanting to see the region dominated by China is a key component of building up our geopolitical relationship," he told The Australian.

The summit also follows recent talks between Australian Foreign Minister Marise Payne and Indian counterpart Subrahmanyam Jaishankar on the pandemic response and Australia's call for an independent inquiry, which was overwhelmingly backed at the World Health Assembly on Tuesday.

Australia wants to support India to develop a domestic critical minerals processing industry, which would provide Western nations with an alternative to sourcing the materials from China.

Meanwhile, India has strong expertise as a manufacturer of drugs and medical equipment, while Australia is a centre of biomedical research, opening the possibility for closer co-operation in the key sector, the media reported further.

Singapore, May 6: Oil prices slipped back Wednesday after two days of gains, although Brent crude remained above $30 a barrel, as renewed US-China tensions offset optimism about the easing of coronavirus lockdowns.

Brent, the international benchmark, fell 1.1 per cent to $30.63 a barrel in early Asian trade. On Tuesday, the contract surged 14 per cent and rose above $30 for the first time since mid-April.

US marker West Texas Intermediate slipped 1.9 per cent and was changing hands for $24.13 a barrel.

Oil markets have been battered as the virus strangled demand due to business closures and travel restrictions, with US crude falling into negative territory last month for the first time.

They started rallying strongly this week as countries from Europe to Asia ease curbs and economies start shuddering back to life.

But gains were capped Wednesday as dealers follow a brewing US-China row after Donald Trump hit out at Beijing over its handling of the outbreak, saying it began in a Wuhan lab, but so far offering no evidence.

"Traders are incredibly cautious this morning, weighing all the possible China responses," said Stephen Innes, chief global market strategist at AxiCorp.

"And the one that would hurt the most would be for China to reduce imports of US oil."

This week's rally was in part driven by a deal agreed between top producers to reduce output by almost 10 million barrels a day, which came into effect on May 1.

There have also been signs that the massive oversupply in the market is starting to ease as demand slowly comes back.

Energy data provider Genscape said earlier this week that stockpiles at the main US oil depot in Cushing, Oklahoma had increased by only 1.8 million barrels last week following weeks of major rises.