Recently, India was again declared free of the H5N1 virus, which causes ‘avian influenza’ or ‘Bird flu’ (earlier declaration in 2017).
WHO defines influenza as a contagious, acute respiratory illness caused by influenza viruses.
The many kinds of viruses causing influenza are identified by a standard nomenclature issued by the WHO in 1980.
It is of four types, A, B, C, and D.
According to the US Centers for Disease Control and Prevention (CDC), only ‘influenza A and B viruses’ are known to cause ‘epidemics’.
The ‘C type’ virus usually causes mild respiratory illness.
The ‘D type’ virus typically affects cattle and is not known to infect humans.
Influenza is known to kill 6.5 lakh people every year, especially young children, elderly, pregnant women or those with vulnerable immune systems.
Only the ‘Influenza A virus’ is divided into subtypes, based on two proteins on the surface of the virus,
Hemagglutinin (H) and Neuraminidase (N)
Hemagglutinin has 18 further subtypes while
Neuraminidase has 11.
They are named from H1 to H18 and N1 to N11 in a sequential system.
Humans can be infected with avian, swine and other zoonotic influenza viruses.
Avian influenza subtypes - A(H5N1), A(H7N9) and A(H9N2).
Swine influenza subtypesn- A(H1N1), A(H1N2) and A(H3N2).
Novel strains of the H1N1 virus have appeared in 1918, 1957, 1968 and most recently in 2009.
WHO designated global ‘bird flu’ outbreak in 2009 as ‘Pandemic’.
Epidemiological Terms to know
Endemic - A disease that exists permanently in a particular geographical region or population.
Epidemic - An infectious disease spreads rapidly to many people at about the same time.
Pandemic - An epidemic spreads throughout the world.
Outbreak - refers to the number of cases (disease) that exceeds what would be expected.
Vehicles Pollution test – PUC Test
Vehicles have to undergo a ‘Pollution Under Control’ (PUC) test, in which a vehicle is certified for a certain period of time.
The fine for PUC violations has now gone up to Rs 10,000 in the recently implemented ‘Motor Vehicles (Amendment) Act, 2019’.
According to the Transport Department, Delhi,
217.7 tonnes of carbon monoxide is emitted every day by vehicles in the city.
84.1 tonnes of nitrogen oxides and 66.7 tonnes of hydrocarbons per day from Vehicular pollution.
The PUC certificate is a document that any person driving a motor vehicle can be asked to produce by a police.
The certificates are issued by authorised pollution checking centres if a vehicle is found complying with the prescribed emission norms.
The test costs between Rs 60 and Rs 100.
The validity of the test is 1 year for BS IV vehicles and 3 months for others.
A PUC certificate contains information such as,
The vehicle’s license plate number,
PUC test reading,
The date on which the PUC test was conducted and
The expiry date of the certificate.
The computerised model for pollution check was developed by the ‘Society of Indian Automobile manufacturers’ (SIAM).
Chandrayaan-2 in perspective
The mission has not failed, although the attempt to land a spacecraft on the Moon certainly has.
The mission comprised an orbiter, a lander and rover, the orbiter part is functioning normally.
When ‘Vikram’ contact was lost, it was travelling at 50 to 60 m/s (180 to 200 km/hour).
But a speed of 2 m/s (7.2 km/hr) was required for a safe landing.
Vikram was designed to absorb the shock of an impact even at 5 m/s (18 km/hr).
At the rate it was decelerating, it could not even have attained a speed of 5m/s before touchdown.
It is likely to have hit the Moon at a far greater speed, possibly damaging itself and instruments on board.
The lander has been located. It was barely a few kilometres from its pre-programmed flight path.
ISRO eventually used the instruments on the orbiter to locate the lander.
The orbiter has only taken a thermal image, possibly because it passed over the site at a time when there was not enough sunlight and not a normal image, which too is possible.
The more difficult part is to restore contact with the lander.
It would depend on how much damage it has suffered, and whether its communication unit is intact.
Restoration of contact can be done only in the next two weeks.
After that, the Moon will enter its night (14 Earth days).
During which temperatures would be so cold.
The instruments are unlikely to behave normally.
It is possible that some of the instruments on the lander are functional.
The instruments, if they can be revived, can possibly take readings and communicate with the ground station.
As of now, it is unlikely that the lander is standing vertically.
The rover could have come out of the lander only when it was standing vertically.
It is therefore unlikely that the rover and the two instruments on it could be put to any use now.
However, ‘Orbiter’ is functioning normally, instruments onboard will conduct most of the mission’s scientific investigations.
Scientists insist that 80-90% of the science output of the mission have to come from orbiter.
