US lawmakers hail Trump for Afghan bombing

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.

Beijing, June 30: China said on Tuesday it was concerned about India’s decision to ban Chinese mobile apps such as Bytedance’s TikTok and Tencent’s WeChat and was making checks to verify the situation.

Chinese foreign ministry spokesman Zhao Lijian told reporters during a daily briefing that (the Prime Minister Narendra Modi-led government of) India has a responsibility to uphold the rights of Chinese businesses.

India on Monday banned 59, mostly Chinese, mobile apps in its strongest move yet targeting China in the online space since a border crisis erupted between the two countries this month.

The apps are “prejudicial to the sovereignty and integrity of India, the defence of India, the security of state and public order", the ministry of information technology said in a statement, which came two weeks after 20 Indian Army personnel were killed in a violent clash on the India-China border in Ladakh.

The companies have been invited to offer clarifications before a government panel, which will decide whether the ban can be removed or will stay.

The move also came ahead of military and diplomatic talks between India and China scheduled this week.

The dollar's dominance will slowly melt away over the coming year on weakening global demand and a sombre U.S. economic outlook, according to a Reuters poll of currency forecasters whose views depend on there being no second coronavirus shock.

Despite fears a surge in new Covid-19 cases would delay economies reopening and stymie a tentative recovery, world stocks have rallied - with the S&P 500 finishing higher in June, marking its biggest quarterly percentage gain since the height of the technology boom in 1998.

Caught between bets in favour of riskier investments, weak U.S. economic prospects as well as an easing in the thirst for dollars after the Federal Reserve flooded markets with liquidity, the greenback fell nearly 1.0 per cent last month. It was its worst monthly performance since December.

While there was a dire prognosis from the top U.S. medical expert on the coronavirus' spread, the June 25-July 1 poll of over 70 analysts showed weak dollar projections as Fed Chair Jerome Powell on Monday reiterated the economic outlook for the world's largest economy was uncertain.

"The dollar rises in two instances: when you see risk off or when there is a situation where the U.S. is leading the global recovery, and we don't think that's going to be the case anytime soon," said Gavin Friend, senior FX strategist at NAB Group in London.

"The U.S. is playing fast and loose with the virus, and chronologically they're behind the rest of the world."

Currency speculators, who had built up trades against the dollar to the highest in two years during May, increased their out-of-favour dollar bets further last week, the latest positioning data showed.

About 80 per cent of analysts, 53 of 66, said the likely path for the dollar over the next six months was to trade around current levels, alternating between slight gains and losses in a range. That suggests the greenback may be at a crucial crossroad as more currency strategists have turned bearish.

But more than 90 per cent, or 63 of 68, said a second shock from the pandemic would push the dollar higher. Five said it would push the U.S. currency lower.

Much will also depend on debt servicing and repayments by Asian, European and other international borrowers in U.S. dollars.

While an early shortage of dollars in March from the pandemic's first shock pushed the Fed to open currency swap lines with major central banks, international funding strains have eased significantly since. In recent weeks, usage of the facility has reduced dramatically.

That trend is expected to continue over the next six months with major central banks' usage of swap lines to "stay around current levels", according to 32 of 46 analysts. While 13 predicted a sharp drop, only one respondent said use of them would "rise sharply".

The dollar index, which measures the greenback's strength against six other major currencies, has slipped over 5 per cent since touching a more than three-year high in March.

When asked which currencies would perform better against the dollar by end-December, a touch over half of 49 respondents said major developed market ones, with the remaining almost split between commodity-linked and emerging market currencies.

"The dollar is so overvalued, and has been overvalued for a long time, it's time now for it to come back down again, as we head towards the (U.S.) election," added NAB's Friend.

Over the last quarter, the euro has staged a 1.8 per cent comeback after falling by a similar margin during the first three months of the year. For the month of June, the euro was up 1.2 per cent against the dollar.

The single currency was now expected to gain about 2.5 per cent to trade at $1.15 in a year from around $1.12 on Wednesday, slightly stronger than $1.14 predicted last month. While those findings are similar to what analysts have been predicting for nearly two years, there was a clear shift in their outlook for the euro, with the range of forecasts showing higher highs and higher lows from last month.

"In comparison to even a month or two ago, the outlook in Europe has improved significantly," said Lee Hardman, currency strategist at MUFG.

"I think that makes the euro look relatively more attractive and cheap against the likes of the dollar. We're not arguing strongly for the euro to surge higher, we're just saying, after the weakness we have seen in recent years, there is the potential for that weakness to start to reverse."