Sheep can recognise Baaaa-Rack Obama’s face: study

Melbourne, Jul 24: Home-made cloth face masks may need a minimum of two layers, and preferably three, to prevent the dispersal of viral droplets associated with Covid-19, according to a study.

Researchers, including those from the University of New South Wales in Australia, noted that viral droplets are generated by those infected with the novel coronavirus when they cough, sneeze, or speak.

As face masks have been proven to protect healthy people from inhaling infectious droplets as well as reducing the spread from those who are already infected, several types of material have been suggested for these, but based on little or no evidence of how well they work, the scientists said.

In the current study, published in the journal Thorax, the researchers compared the effectiveness of single and double-layer cloth face coverings with a surgical face mask (Bao Thach) at reducing droplet spread.

They said the single layer covering was made from a folded piece of cotton T shirt and hair ties, and the double layer covering was made using the sew method described by the US Centers for Disease Control and Prevention (CDC).

The scientists used a tailored LED lighting system and a high-speed camera to film the dispersal of airborne droplets produced by a healthy person with no respiratory infection, during speaking, coughing, and sneezing while wearing each type of mask.

Their analysis showed that the surgical face mask was the most effective at reducing airborne droplet dispersal, although even a single layer cloth face covering reduced the droplet spread from speaking.

But the study noted that a double layer covering was better than a single layer in reducing the droplet spread from coughing and sneezing.

According to the researchers, the effectiveness of cloth face masks is dependent on the number of layers of the covering, the type of material used, design, fit as well as the frequency of washing.

Based on their observations, they said a home made cloth mask with at least two layers is preferable to a single layer mask.

"Guidelines on home-made cloth masks should stipulate multiple layers," the scientists said, adding that there is a need for more research to inform safer cloth mask design.

Social media platform WhatsApp assured the Supreme Court on Wednesday that it will not roll out its payment services without complying with all payment regulations and norms in the country.

A bench headed by Chief Justice S.A. Bobde and comprising Justices Indu Malhotra and Hrishikesh Roy took up the matter through video conferencing. Senior advocate Kapil Sibal, representing the social media platform, said "WhatsApp Inc makes a statement on behalf of his client that they will not go ahead with the payments' scheme without complying with all the regulations in force."

The statement was made during the hearing of a petition seeking a ban on payment through WhatsApp, as it does not conform to the data localization norms. The top court took the assurance made by WhatsApp on record.

WhatsApp made the statement during the hearing of a plea seeking a ban on its payment service, for not being in line with data localization norms.

In 2018, WhatsApp was granted a beta licence to launch its payment service, but a dedicated and separate app is yet to be launched. A petition was moved in the apex court that WhatsApp's existing model for its payments service should be declared inconsistent with the Unified Payment Interface (UPI) Scheme, as a separate dedicated app has not been offered by the company.

The petitioner NGO, Good Governance Chambers, argued that the National Payments Corporation of India (NPCI) and the Reserve Bank of India (RBI) must change its model on the lines of the UPI payment scheme, and its operations may be suspended until these conditions are met.

The apex court today asked the Centre, Facebook and WhatsApp to file their replies within three weeks and it will take up the matter thereafter. The court noted that the government may process the applications filed by WhatsApp in accordance with the law and there is no stay on the same. Facebook was represented by senior advocate Arvind Datar.

The petitioner argued that lapses have been found in relation to WhatsApp's claims of having a secure and safe technological interface for securing sensitive user data.