Luminous galaxy reionizing surroundings 13 billion years ago

Bengaluru, Jan 17: India’s latest communication satellite GSAT-30 was successfully launched from the Spaceport in French Guiana during the early hours on Friday.

In a press release, ISRO, has stated that the launch vehicle 'Ariane-5 VA-251' was blasted off from Kourou Launch Base, French Ginana at 0230 hours, carrying India’s GSA-30 and EUTELSAT KONNECT for Eutelasat, as per schedule.

The Ariane 5 upper stage in an elliptical Geosynchronous Transfer Orbit.

With a lift-off mass of 3,357 kg, GSAT-30 will provide continuity to operational services on some of the in-orbit satellites.

GSAT-30 derives its heritage from ISRO’s earlier INSAT/GSAT satellite series and will replace INSAT-4A in orbit.

“GSAT-30 has a unique configuration of providing flexible frequency segments and flexible coverage. The satellite will provide communication services to Indian mainland and islands through Ku-band and wide coverage covering Gulf countries, a large number of Asian countries and Australia through C-band," ISRO Chairman Dr K Sivan said.

Dr Sivan also said that “GSAT-30 will provide DTH Television Services, connectivity to VSATs for ATM, Stock-exchange, Television uplinking and teleport Services, Digital Satellite News Gathering (DSNG) and e-governance applications. The satellite will also be used for bulk data transfer for a host of emerging telecommunication applications.”

ISRO’s Master Control Facility (MCF) at Hassan in Karnataka took over the command and control of GSAT-30 immediately after its separation from the launch vehicle. Preliminary health checks of the satellite revealed its normal health.

In the days ahead, orbit-raising maneuvers will be performed to place the satellite in Geostationary Orbit (36,000 km above the equator) by using its onboard propulsion system.

During the final stages of its orbit raising operations, the two solar arrays and the antenna reflectors of GSAT-30 will be deployed. Following this, the satellite will be put in its final orbital configuration.

The satellite will be operational after the successful completion of all in-orbit tests.

Thiruvananthapuram, Mar 18: To raise awareness about protective measures against coronavirus, Kerala Police released a dance video on the State Police Media Centre's Facebook page promoting the washing of hands, here on Tuesday.

In the video, the police officers were seen dancing to the tunes of Kalakkatha from the Malayalam action-drama thriller Ayyappanum Koshiyum while demonstrating the right technique for washing hands.

The video gained over 27,000 likes and over 2,400 comments and more than 33,000 netizens shared the video.

The video has received a positive response with users congratulating Kerala Police for the initiative.

"Congrats Kerala police media for this kind of initiative," one user commented on Facebook. Another user thanked the police in the comments section saying, "Super super thanks to KL (Kerala) police."

The number of people who have tested positive for the coronavirus in Kerala is 25.

The total number of confirmed COVID-19 cases in India has reached 147, including 122 Indians and 25 foreign nationals, said the Ministry of Health and Family Welfare earlier today.

Globally, the virus has infected more than 184,000 people and killed more than 7500, as per the data available on the World Health Organisation website.

Paris, Apr 17: Even as virologists zero in on the virus that causes COVID-19, a very basic question remains unanswered: do those who recover from the disease have immunity?

There is no clear answer to this question, experts say, even if many have assumed that contracting the potentially deadly disease confers immunity, at least for a while.

"Being immunised means that you have developed an immune response against a virus such that you can repulse it," explained Eric Vivier, a professor of immunology in the public hospital system in Marseilles.

"Our immune systems remember, which normally prevents you from being infected by the same virus later on."

For some viral diseases such a measles, overcoming the sickness confers immunity for life.

But for RNA-based viruses such as Sars-Cov-2 -- the scientific name for the bug that causes the COVID-19 disease -- it takes about three weeks to build up a sufficient quantity of antibodies, and even then they may provide protection for only a few months, Vivier told AFP.

At least that is the theory. In reality, the new coronavirus has thrown up one surprise after another, to the point where virologists and epidemiologists are sure of very little.

"We do not have the answers to that -- it's an unknown," Michael Ryan, executive director of the World Health Organization's Emergencies Programme said in a press conference this week when asked how long a recovered COVID-19 patient would have immunity.

"We would expect that to be a reasonable period of protection, but it is very difficult to say with a new virus -- we can only extrapolate from other coronaviruses, and even that data is quite limited."

For SARS, which killed about 800 people across the world in 2002 and 2003, recovered patients remained protected "for about three years, on average," Francois Balloux director of the Genetics Institute at University College London, said.

"One can certainly get reinfected, but after how much time? We'll only know retroactively."

A recent study from China that has not gone through peer review reported on rhesus monkeys that recovered from Sars-Cov-2 and did not get reinfected when exposed once again to the virus.

"But that doesn't really reveal anything," said Pasteur Institute researcher Frederic Tangy, noting that the experiment unfolded over only a month.

Indeed,several cases from South Korea -- one of the first countries hit by the new coronavirus -- found that patients who recovered from COVID-19 later tested positive for the virus.

But there are several ways to explain that outcome, scientists cautioned.

While it is not impossible that these individuals became infected a second time, there is little evidence this is what happened.

More likely, said Balloux, is that the virus never completely disappeared in the first place and remains -- dormant and asymptomatic -- as a "chronic infection", like herpes.

As tests for live virus and antibodies have not yet been perfected, it is also possible that these patients at some point tested "false negative" when in fact they had not rid themselves of the pathogen.

"That suggests that people remain infected for a long time -- several weeks," Balloux added. "That is not ideal."

Another pre-publication study that looked at 175 recovered patients in Shanghai showed different concentrations of protective antibodies 10 to 15 days after the onset of symptoms.

"But whether that antibody response actually means immunity is a separate question," commented Maria Van Kerhove, Technical Lead of the WHO Emergencies Programme.

"That's something we really need to better understand -- what does that antibody response look like in terms of immunity."

Indeed, a host of questions remain.

"We are at the stage of asking whether someone who has overcome COVID-19 is really that protected," said Jean-Francois Delfraissy, president of France's official science advisory board.

For Tangy, an even grimmer reality cannot be excluded.

"It is possible that the antibodies that someone develops against the virus could actually increase the risk of the disease becoming worse," he said, noting that the most serious symptoms come later, after the patient had formed antibodies.

For the moment, it is also unclear whose antibodies are more potent in beating back the disease: someone who nearly died, or someone with only light symptoms or even no symptoms at all. And does age make a difference?

Faced with all these uncertainties, some experts have doubts about the wisdom of persuing a "herd immunity" strategy such that the virus -- unable to find new victims -- peters out by itself when a majority of the population is immune.

"The only real solution for now is a vaccine," Archie Clements, a professor at Curtin University in Perth Australia, told AFP.

At the same time, laboratories are developing a slew of antibody tests to see what proportion of the population in different countries and regions have been contaminated.

Such an approach has been favoured in Britain and Finland, while in Germany some experts have floated the idea of an "immunity passport" that would allow people to go back to work.

"It's too premature at this point," said Saad Omer, a professor of infectious diseases at the Yale School of Medicine.

"We should be able to get clearer data very quickly -- in a couple of months -- when there will be reliable antibody tests with sensitivity and specificity."

One concern is "false positives" caused by the tests detecting antibodies unrelated to COVID-19.

The idea of immunity passports or certificates also raises ethical questions, researchers say.

"People who absolutely need to work -- to feed their families, for example -- could try to get infected," Balloux.