India ranks 110th on Sustainable Development index

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.

New Delhi, Apr 17: The Indian Railways turned 167 years old on Thursday and for the first time ever, its trains did not carry any passengers on its birthday and instead stood idle in the yards waiting for the nationwide lockdown to end.

On this day 167 years ago, the wheels of the first passenger train in the country from Mumbai to Thane started rolling.

In 1974, Indians experienced life without trains for the first time. In May 1974 during the strike of the railways that lasted for around three weeks, drivers, station masters, guards, track staff and many others went on 'chakka jam' demanding fixed working hours for train drivers and an across-the-board pay hike.

"I can recall those times vividly. I remember that our leader George Fernandes had almost secured a deal with the then railway minister, but it fell through when it was taken to the then Prime Minister Indira Gandhi," All India Railwaymens Federation General Secretary Shiv Gopal Mishra, who was an apprentice in the railways at that time, told PTI.

"Fernandes was arrested in Lucknow. The workers went through a lot at that time. But those were days that angry workers had refused to give in and took great risks to get their demands met," he said.

However, just like this time, four decades ago too freight trains carrying essential supplies were run and the unions agreed to let some passenger trains run on the trunk routes like the Kalka Mail from Howrah to Delhi.

"Never ever in its history, there has been such a long interruption of services. Not during the World Wars, not during the 1974 railway strike, or any other national calamity or natural disaster," a railway spokesperson said.

The first Indian Railways passenger train was flagged off on April 16, 1853, from Mumbai to nearby Thane.

On Thursday, the Railway Ministry wished the railways a happy birthday on Twitter - "Today, 167 years ago with the zeal of 'never to stop' the wheels of the first passenger train from Mumbai to Thane started rolling. For the first time, passenger services are stopped for your safety. Stay indoors & make the nation victorious," it said.

Railway has suspended all passenger services since March 25 till May 3 due to the coronavirus outbreak. Around 15,523 trains run by the railways have been affected including 9,000 passenger trains and 3,000 mail express services which are run daily. It caters to over 20 million passengers every day.

According to the Union health ministry, the death toll due to coronavirus rose to 414 and the number of cases to 12,380 in the country on Thursday.

Washington D.C., Feb 6: An international team of astronomers has found an unusual monster galaxy that existed about 12 billion years ago when the universe was only 1.8 billion years old.

The team of astronomers was led by scientists at the University of California, Riverside.

Dubbed XMM-2599, the galaxy formed stars at a high rate and then died. Why it suddenly stopped forming stars is unclear.

"Even before the universe was 2 billion years old, XMM-2599 had already formed a mass of more than 300 billion suns, making it an ultra massive galaxy," said Benjamin Forrest, a postdoctoral researcher in the UC Riverside Department of Physics and Astronomy and the study's lead author.

"More remarkably, we show that XMM-2599 formed most of its stars in a huge frenzy when the universe was less than 1 billion years old and then became inactive by the time the universe was only 1.8 billion years old," Forrest added.

The team used spectroscopic observations from the W. M. Keck Observatory's powerful Multi-Object Spectrograph for Infrared Exploration or MOSFIRE, to make detailed measurements of XMM-2599 and precisely quantify its distance.

The study results appear in the Astrophysical Journal.

"In this epoch, very few galaxies have stopped forming stars, and none are as massive as XMM-2599," said Gillian Wilson, a professor of physics and astronomy at UCR in whose lab Forrest works.

"The mere existence of ultramassive galaxies like XMM-2599 proves quite a challenge to numerical models. Even though such massive galaxies are incredibly rare at this epoch, the models do predict them."

"The predicted galaxies, however, are expected to be actively forming stars. What makes XMM-2599 so interesting, unusual, and surprising is that it is no longer forming stars, perhaps because it stopped getting fuel or its black hole began to turn on. Our results call for changes in how models turn off star formation in early galaxies," the professor stated.

The research team found XMM-2599 formed more than 1,000 solar masses a year in stars at its peak of activity -- an extremely high rate of star formation. In contrast, the Milky Way forms about one new star a year.

"XMM-2599 may be a descendant of a population of highly star-forming dusty galaxies in the very early universe that new infrared telescopes have recently discovered," said Danilo Marchesini, an associate professor of astronomy at Tufts University and a co-author on the study.

"We have caught XMM-2599 in its inactive phase," Wilson said, who led the W. M. Keck Observatory data acquisition
Co-author Michael Cooper, a professor of astronomy at UC Irvine, said this outcome is a strong possibility.

"Perhaps during the following 11.7 billion years of cosmic history, XMM-2599 will become the central member of one of the brightest and most massive clusters of galaxies in the local universe," he said.

"Alternatively, it could continue to exist in isolation. Or we could have a scenario that lies between these two outcomes," he stated.

The study was supported by grants from the National Science Foundation and NASA.