Global mobile phone shipments to decline 14.6% in 2020: Gartner

Toronto, May 7: Scientists have uncovered how bats can carry the MERS coronavirus without getting sick, shedding light on what triggers coronaviruses, including the one behind the COVID-19 pandemic, to jump to humans.

According to the study, published in the journal Scientific Reports, coronaviruses like the Middle East respiratory syndrome (MERS) virus, and the COVID19-causing SARS-CoV-2 virus, are thought to have originated in bats.

While these viruses can cause serious, and often fatal disease in people, bats seem unharmed, the researchers, including those from the University of Saskatchewan (USask) in Canada, said.

"The bats don't get rid of the virus and yet don't get sick. We wanted to understand why the MERS virus doesn't shut down the bat immune responses as it does in humans," said USask microbiologist Vikram Misra.

In the study, the scientists demonstrated that cells from an insect-eating brown bat can be persistently infected with MERS coronavirus for months, due to important adaptations from both the bat and the virus working together.

"Instead of killing bat cells as the virus does with human cells, the MERS coronavirus enters a long-term relationship with the host, maintained by the bat's unique 'super' immune system," said Misra, one of the study's co-authors.

"SARS-CoV-2 is thought to operate in the same way," he added.

Stresses on bats, such as wet markets, other diseases, and habitat loss, may have a role in coronavirus spilling over to other species, the study noted.

"When a bat experiences stress to their immune system, it disrupts this immune system-virus balance and allows the virus to multiply," Misra said.

The scientists, involved in the study, had earlier developed a potential treatment for MERS-CoV, and are currently working towards a vaccine against COVID-19.

While camels are the known intermediate hosts of MERS-CoV, they said bats are suspected to be the ancestral host.

There is no vaccine for either SARS-CoV-2 or MERS, the researchers noted.

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"We see that the MERS coronavirus can very quickly adapt itself to a particular niche, and although we do not completely understand what is going on, this demonstrates how coronaviruses are able to jump from species to species so effortlessly," said USask scientist Darryl Falzarano, who co-led the study.

According to Misra, coronaviruses rapidly adapt to the species they infect, but little is known on the molecular interactions of these viruses with their natural bat hosts.

An earlier study had shown that bat coronaviruses can persist in their natural bat host for at least four months of hibernation.

When exposed to the MERS virus, the researchers said, bat cells adapt, not by producing inflammation-causing proteins that are hallmarks of getting sick, but instead by maintaining a natural antiviral response.

On the contrary, they said this function shuts down in other species, including humans.

The MERS virus, the researchers said, also adapts to the bat host cells by very rapidly mutating one specific gene.

These adaptations, according to the study, result in the virus remaining long-term in the bat, but being rendered harmless until something like a disease, or other stressors, upsets this balance.

In future experiments, the scientists hope to understand how the bat-borne MERS virus adapts to infection and replication in human cells.

"This information may be critical for predicting the next bat virus that will cause a pandemic," Misra said.

Kolkata, May 15: Veteran Bengali author Debesh Roy, who was conferred the Sahitya Akademi award for his novel 'Teesta Parer Brittanto', died at a private hospital in Kolkata on Thursday, his family members said.

Roy was 84 and he is survived by his son. His wife had died earlier.

He was admitted to the hospital near his residence at Baguihati, in the eastern fringes of the city, on Wednesday after having symptoms like sodium potasium imbalance, sugar problem and breathing problem, his family members said.

He suffered a massive cardiac arrest and died at 10.50 PM.

A regular contributor to a number of Bengali dailies, he was a staunch critic of the attacks on liberals by in the country in recent times and attended protest meetings despite his failing health.

He was born in Pabna in present-day Bangladesh on December 17, 1936. He had five decades of career as a writer.

Besides Teesta Parer Britanta', he will be remembered for books like Borisaler Jogen Mondal , Manush Khun Kore Keno and Samay Asamayer Brittanto . His first book was Jajati.

His last rites will be performed tomorrow.

U.S. electric vehicle maker Tesla Inc is "very close" to achieving level 5 autonomous driving technology, Chief Executive Elon Musk said on Thursday, referring to the capability to navigate roads without any driver input.

"I'm extremely confident that level 5 or essentially complete autonomy will happen and I think will happen very quickly," Musk said in remarks made via a video message at the opening of Shanghai's annual World Artificial Intelligence Conference (WAIC).

"I remain confident that we will have the basic functionality for level 5 autonomy complete this year."

Automakers and tech companies including Alphabet Inc Waymo and Uber Technologies are investing billions in the autonomous driving industry.

However industry insiders have said it would take time for the technology to get ready and public to trust autonomous vehicles fully.

The California-based automaker currently builds cars with an Autopilot driver-assistance system.

Tesla is also developing new heat-projection or cooling systems to enable more advanced computers in cars, Musk said.

Industry data showed Tesla sold nearly 15,000 China-made Model 3 sedans last month.

Tesla has become the highest-valued automaker as its shares surged to record highs and its market capitalisation overtook that of former front-runner Toyota Motors Corp.