Li-Fi, or light fidelity, invented by German physicist and professor Harald Haas, is a wireless technology that makes use of visible light in place of radio waves to transmit data at terabits per second speeds—more than 100 times the speed of Wi-Fi. Li-Fi offers great promise to overcome the existing limitations of Wi-Fi by providing for data-heavy communication in short ranges. Li-Fi can also easily work underwater, where Wi-Fi fails completely, thereby throwing open endless opportunities for military and navigational operations.

Kala-azar or visceral leishmaniasis (VL) is a tropical disease characterised by irregular fever, weight loss, anaemia and swelling of the spleen and liver.

It is caused by a protozoan Leishmania parasite and is transmitted to humans by the bite of infected female sandflies.

According to the World Health Organisation (WHO), globally, about 7 to 10 lakh new cases occur annually.

India accounts for about two-thirds of the total global cases, and the disease is endemic to Bihar, Jharkhand, Uttar Pradesh and West Bengal.

An initiative was launched by WHO to eliminate VL as a public health problem from the South East Asia region by 2020.

The deadline has now been extended to 2023.

At a time when the world grapples with highly treatment-resistant tuberculosis, the recently approved three-drug regimen to tackle the condition has shown a 90 per cent favourable outcome, according to a new study.

Japan’s Hayabusa2 spacecraft left the asteroid Ryugu a year ago and is expected to reach Earth and drop a capsule containing the precious samples in southern Australia on December 6.

The soil samples and data from the asteroid could provide clues to the origins of the solar system.

 

Hayabusa2 project:

It is an asteroid sample-return mission operated by the Japanese space agency, JAXA.

In a rare complication, some patients infected with Covid-19 have been found suffering from Guillain Barre Syndrome (GBS).

In India, such cases have been reported since August.

 

What is Guillain Barre Syndrome?

It is a very rare autoimmune disorder.

The immune system, in an attempt to kill the coronavirus, accidentally starts attacking the peripheral nervous system.

GBS is caused by bacteria or viral infection.

In the past, patients of Middle East Respiratory Syndrome showed GBS symptoms, as did those infected with Zika, HIV, Herpes virus and Campylobacter jejuni.

At any time after the expiration of three years from the date of the grant of a patent, any person interested may make an application to the Controller for grant of compulsory licence on patent on any of the following grounds, namely

that the reasonable requirements of the public with respect to the patented invention have not been satisfied, or

that the patented invention is not available to the public at a reasonably affordable price, or

that the patented invention is not worked in the territory of India.

It is sometimes thought that everyone who is infected with a disease-causing virus, and recovers, becomes immune to the disease, because they build antibodies against it.

But that is not the case.

While the creation of antibodies is necessary for the recovery process, it does not guarantee immunity against a future attack from the same virus.

Immunity comes from what are known as “neutralising” or “protective” antibodies.

The neutralising antibodies become special because they have the ability to thwart the entry of the same virus inside human bodies in the future.

Serosurveys only look for the presence of antibodies in people.

Their purpose is to find out whether a person has been infected with the virus or not, and through random testing of people, estimate the extent of spread of the disease, or prevalence, in a population group.

Aditya – L1:

First Indian mission to study the Sun

The Aditya-1 mission was conceived as a 400kg class satellite carrying one payload, the Visible Emission Line Coronagraph (VELC) and was planned to launch in a 800 km low earth orbit.

A Satellite placed in the halo orbit around the Lagrangian point 1 (L1) of the Sun-Earth system has the major advantage of continuously viewing the Sun without any occultation/ eclipses.

Therefore, the Aditya-1 mission has now been revised to “Aditya-L1 mission” and will be inserted in a halo orbit around the L1, which is 1.5 million km from the Earth.

The satellite carries additional six payloads with enhanced science scope and objectives.

It is planned to be launched on the PSLV-C56 in December 2021 or January 2022.

Sunspots are temporary phenomena on the Sun’s photosphere that appear as spots darker than the surrounding areas.

They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection.