Chennai boy bags NASA prize for his proposal on connecting Earth with Moon via elevator

Washington DC, Jun 8: Astronomers acting on a hunch have likely resolved a mystery about young, still-forming stars and regions rich in organic molecules closely surrounding some of them.

They used the National Science Foundation's Karl G Jansky Very Large Array (VLA) to reveal one such region that previously had eluded detection and that revelation answered a longstanding question.

The regions around the young protostars contain complex organic molecules which can further combine into prebiotic molecules that are the first steps on the road to life.

The regions, dubbed "hot corinos" by astronomers, are typically about the size of our solar system and are much warmer than their surroundings, though still quite cold by terrestrial standards.

The first hot corino was discovered in 2003 and only about a dozen have been found so far. Most of these are in binary systems, with two protostars forming simultaneously.

Astronomers have been puzzled by the fact that, in some of these binary systems, they found evidence for a hot corino around one of the protostars but not the other.

"Since the two stars are forming from the same molecular cloud and at the same time, it seemed strange that one would be surrounded by a dense region of complex organic molecules and the other wouldn't," said Cecilia Ceccarelli, of the Institute for Planetary Sciences and Astrophysics at the University of Grenoble (IPAG) in France.

The complex organic molecules were found by detecting specific radio frequencies, called spectral lines, emitted by the molecules. Those characteristic radio frequencies serve as "fingerprints" to identify the chemicals.

The astronomers noted that all the chemicals found in hot corinos had been found by detecting these "fingerprints" at radio frequencies corresponding to wavelengths of only a few millimetres.

"We know that dust blocks those wavelengths, so we decided to look for evidence of these chemicals at longer wavelengths that can easily pass through dust," said Claire Chandler of the National Radio Astronomy Observatory, and principal investigator on the project.

"It struck us that dust might be what was preventing us from detecting the molecules in one of the twin protostars," added Chandler.

The astronomers used the VLA to observe a pair of protostars called IRAS 4A, in a star-forming region about 1,000 light-years from Earth. They observed the pair at wavelengths of centimetres.

At those wavelengths, they sought radio emissions from methanol, CH3OH (wood alcohol, not for drinking). This was a pair in which one protostar clearly had a hot corino and the other did not, as seen using the much shorter wavelengths.

The result confirmed their hunch. "With the VLA, both protostars showed strong evidence of methanol surrounding them. This means that both protostars have hot corinos. The reason we did not see the one at shorter wavelengths was because of dust," said Marta de Simone, a graduate student at IPAG who led the data analysis for this object.

The astronomers cautioned that while both hot corinos now are known to contain methanol, there still may be some chemical differences between them. That, they said, can be settled by looking for other molecules at wavelengths not obscured by dust.

"This result tells us that using centimetre radio wavelengths is necessary to properly study hot corinos," Claudio Codella of Arcetri Astrophysical Observatory in Florence, Italy, said.

"In the future, planned new telescopes such as the next-generation VLA and SKA, will be very important to understanding these objects," added Codella.

In an unprecedented crisis despite Prime Minister Narendra Modi assuring the continuation of essential services like food and groceries, online marketplaces like Flipkart and Amazon along with delivery platforms like Bigbasket, Grofers and FreshToHomes hit a major blockade on Wednesday as local authorities shut warehouses and sent delivery boys back, even harassed them.

Millions of people across cities were left helpless at homes as essential items like fruits and vegetables, dairy and milk, meat and fish etc did not reach their doors despite placing orders well in advance. Later, the orders went dry.

While Grofers' warehouse in Faridabad was closed by the local law enforcement agencies, Bigbasket complained that the police stopped its delivery partners and "some of them were even beaten up by for no fault of theirs".

"We are not operational due to restrictions imposed by local authorities on movement of goods in spite of clear guidelines provided by central authorities to enable essential services. We are working with the authorities to be back soon,' Bigbasket tweeted.

In a statement to IANS, Bigbasket said that it will help to have better coordination between the Centre and state, and between the state and local police to "ensure that our delivery vans and bikes don't get stopped by the police. Bigbasket and bb daily are not taking new orders".

Furious people stormed the social media platforms, writing their plight to NITI Aayog CEO Amitabh Kant on Twitter.

"Sir, all e-commerce are down. Believe me I tried everything (Grofers, Bigbasket, Flipkart, Amazon, Big Bazaar), no delivery till 31st March or Server Down or No Service. Need to think how we can enable them through digital India," tweeted one user.

Kant tweeted back to Bigbasket: "They should give me specifics - State & location. I will act on it by getting in touch with concerned authorities & sorting it out. Govt guidelines exempt them. We will ensure that citizens are not impacted".

Kant also responded to Grofers: "Cold storages & Warehouses as well as delivery of all essentials goods including food, pharma thru E-Commerce are exempted under MHA order. I have spoken to CS & DGP, Haryana . They have taken immediate action to ensure that supply chains efficiently function for the citizens".

The subscription-based hyperlocal delivery startup FreshToHome sent messages to its customers, saying that despite the government declaring food delivery as essential, "we are facing hardships in continuing our operations".

"Please bear with us as we are working hard to unblock local authority hurdles," said the FreshToHome team.

Reports later surfaced that the Department for Promotion of Industry and Internal Trade (DPIIT) has initiated talks with the state Chief Secretaries asking them not to restrict movement of people engaged in home delivery of essential items, mentioned in the list of exempted items circulated by the Home Ministry.

Meanwhile, Flipkart said it has temporarily suspended its operations and services - including grocery items. The marketplace has decided to halt all orders from March 25 for all three supply chains -- groceries, non-large goods and large items.

"Flipkart has temporarily suspended orders as we assess the possibilities of operating in the lockdown. We are prioritising the safety of our delivery executives and seeking the support of the local governments and police authorities to meet the needs of our customers as they stay home during this lockdown," Rajneesh Kumar, Chief Corporate Affairs Officer, Flipkart, said in a statement.

E-commerce giant Amazon said the company has to "temporarily stop taking orders and disable shipments for lower-priority products.

"For all pending customer orders on lower-priority products, we are reaching out to customers and giving them a choice to cancel their orders, and receive a refund for prepaid items," said the company.

Witnessing a surge in demand, supermarket chain Biz Bazaar entered the fray, with launching doorstep delivery services in major cities like Delhi, Mumbai, Bengaluru and Gurugram.

However, within no time, Big Bazaar was flooded with calls, forcing the company to issue a statement, saying that "In light of the recent announcement, we are receiving an unprecedented number of requests for doorstep delivery. There could be a delay due to the restrictions on movements".

Already battling massive surge in demand, the online delivery platforms faced other issues too, including zero access to several high-rises across the country which have gone under complete lockdown with all entry and exit gates locked.

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.