Pune man 'spots' alien object outside his window, writes to PMO

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.

With the scrapping of Mitron and Remove China Apps from its Play Store gaining a lot of attention in India, Google on Thursday said that it removed a video app "for a number of technical policy violations", while adding that it also does not allow an app that "encourages or incentivizes users into removing or disabling third-party apps".

Both the apps became immensely popular in India within a short span of time due to the prevailing anti-China sentiment amid border tensions between India and China in Ladakh and calls by Indian activists to boycott Chinese products.

Reports suggested that the Mitron app is a repackaged version of TicTic, which is a TikTok clone.

The Remove China Apps was designed to help users identify applications of Chinese origin.

Without naming the apps, Google hinted that the Mitron app may make a comeback on the Play Store once it fixes some technical issues, but the chances of the Remove China Apps are thin.

"We have an established process of working with developers to help them fix issues and resubmit their apps. We've given this developer (of the video app) some guidance and once they've addressed the issue the app can go back up on Play," Sameer Samat, Vice President, Android and Google Play, said in a statement.

Google said that its Android app store was designed to provide a safe and secure experience for the consumers while also giving developers the platform and tools they need to build sustainable businesses.

Samat said that Google Play recently suspended a number of apps for violating the policy that it does not allow an app that "encourages or incentivizes users into removing or disabling third-party apps or modifying device settings or features unless it is part of a verifiable security service".

"This is a longstanding rule designed to ensure a healthy, competitive environment where developers can succeed based upon design and innovation. When apps are allowed to specifically target other apps, it can lead to behaviour that we believe is not in the best interest of our community of developers and consumers," Samat said.

"We've enforced this policy against other apps in many countries consistently in the past - just as we did here," he added.

Citing the current dismal aviation scenario, Air India is terminating the services of trainee cabin crew and cabin crew by withdrawing the offer of employment of those who were under training.

As per sources, the new crew and trainee pilots might reduce contracts from five years to one year. Sources said Air India is terminating 1,200 crew and employees who are more than 55-yr-old including 190 trainee pilots.

In a letter reviewed by IANS, Air India has informed an applicant who had been selected as cabin crew in August 2019 subject to successful completion of training.

"On behalf of Air India we would like to thank you for the interest shown by you in joining our organization. However, in view of the current aviation scenario, it would not be possible for Air India to impart any further training to you for engaging your services," the company said.

"In view of the above reasons, which are beyond the control of the company, it has been decided to discontinue your training arrangements and dispense with the offer of engagement with immediate effect. The bank guarantee furnished by you at the time of joining is returned herewith," Air India told the cabin crew.

"Once again on behalf of Air India we thank you for your cooperation and trust that you will appreciate the circumstances under which we are constrained to discontinue the training arrangements," the carrier said.