Thailand Corals Getting Destroyed

• According to recent reports, Thailand's enormous tracts of the ocean floor are being destroyed by a condition known as yellow band disease that is fast spreading.
• The reefs may be more susceptible to yellow-band disease as a result of overfishing, pollution, and rising water temperatures brought on by climate change.

More on the news:

• The corals' colour changes to yellow just before they are killed.
• It was initially discovered decades ago, and the Caribbean reefs have suffered extensive damage as a result. The affected area of the sea is more than 600 acres.
• Corals that have been exposed to this yellow-band illness cannot survive. They'll pass away gradually.

Impact:

• The ecology may suffer greatly if coral populations decline.
• Massive numbers of life are supported by the reef, which is "like a forest," and its demise could someday affect humans as well.

About disease:

• A bacterial infection known as "yellow-band disease" affects coral, leaving behind discoloured bands of pale-yellow or white lesions on the colony's surface.
• The lesions are where the symbiotic photosynthetic algae, known as zooxanthellae, which are a significant source of energy for the coral, were killed by the bacteria.
• The coral starves as a result of this cellular damage and the loss of its primary energy supply, which typically results in coral death. There is proof that the sickness may be getting worse due to climate change.
• Coral and zooxanthellae live in symbiosis and exchange glucose, glycerol, and amino acids.
• Corals will appear stressed when the water's parameters are met, such as changing water temperatures and an increase in nitrogenous waste.
• Additionally, under these circumstances, bacteria can flourish inside coral and compete with zooxanthellae.
• By hindering the zooxanthellae's ability to undergo mitosis and perform photosynthesis, the bacteria finally kills the organism by causing the recognisable pale yellow lesions.

About corals:

• Corals are invertebrate animals that are part of the Cnidaria phylum, a diverse and intriguing group of colourful creatures. Jelly fish and sea anemones are further members of this group that you may have spotted in rock pools or on the beach.
• Each individual coral animal is known as a polyp, and the majority of them live in colonies made up of hundreds to thousands of genetically similar polyps.
• The original polyp physically produces copies of itself during a process known as budding, which is how the colony is created.
• Hard coral and soft coral are the two main categories of coral.
• Hard coral, commonly referred to as "reef building" corals, is one of the 800 or so types of known coral.
• Sea fans, sea feathers, and sea whips are examples of soft corals. Unlike the hard coral, which have calcareous skeletons that resemble rocks, soft corals develop fleshy rinds and wood-like cores for support.

About coral reefs:

• Coral reefs are formed by millions of microscopic polyps that build substantial carbonate structures.
• Coral reefs serve as the foundation and the habitat for hundreds of thousands, if not millions, of different species. The world's largest living structure and the only one that can be seen from space are coral reefs.

Coral reef characteristics:

• They can be found in shallow tropical locations with warm, clear, and clean seawater.
• With more than 800 different kinds of coral, coral reefs are one of the most diverse ecosystems on the planet, offering habitat and protection to almost 25% of all marine life.

Importance of coral reefs:

• They shield coasts from tropical storms, support 1 billion people with food and income, and bring in $9.6 billion in annual tourist and recreation.
• Functions of coral reefs include: providing substrate for mangroves, shelter for plants and fauna, and natural barriers against erosion and storm surge.

Circumstances for coral reef growth:

• The water shouldn't be any colder than 20°C. Between 23°C and 25°C is the ideal temperature for the development of coral reefs. No more than 35°C should be present.
• Only saline environments with an average salinity between 27% and 40% are suitable for coral survival.
• Coral reefs thrive in shallow water that is less than 50 metres deep. The water shouldn't be deeper than 20 feet.

How does a coral reef appear?

Atoll formation according to Darwin's three stages:

Coral reefs were first categorised by Charles Darwin according to their shape and structure, and were given the following descriptions:

• Near emerging land, there are Fringing reefs. They are relatively new, narrow, and shallow. A navigable waterway, which is sometimes wrongly called a "lagoon," might divide them from the coast.
• Barrier reefs are larger and are located further inland. A body of water that can be several miles broad and several tens of metres deep separates them from the coast. On top of a barrier reef, sandy islands with a distinctive pattern of vegetation have occasionally emerged. These islands' coastline is divided by passes that have taken over the former riverbeds.
• Atolls are sizable, ring-shaped offshore reefs with a lagoon in the centre. The most distinctive flora growing on these reefs is composed of coconut trees, and the emergent portion of the reef is frequently covered with accumulated sediments. On islands that are submerged in water or islands that sink, atolls grow close to the water's surface.

Green Comet

After 50,000 years, the Comet C/2022 E3 (ZTF), sometimes known as the "Green Comet," is now approaching Earth.

More on the news:

• The US-based Zwicky Transient Facility (ZTFwide-field )'s survey camera made the initial discovery of the comet in March 2022.
• Following its first discovery by the Zwicky Transient Facility (ZTF), the comet was named C/2022 E3 (ZTF).
• It is currently travelling away from the sun along its own orbit after coming close to it in the middle of January.
• Several locations across the world may now see the comet as it approaches Earth.
• The comet, which originates from the Oort cloud, is predicted to orbit the sun once every 50,000 years.
• "Home of the Comets" refers to the Oort cloud at the frontier of our solar system.

Coming close to Earth:

• Comets can be dragged out of their habitats in the Kuiper Belt or Oort Cloud by the gravitational attraction of a planet or star. A comet may be steered toward the Sun by this tug.
• These comets' rerouted courses resemble lengthy, stretched ovals. They become heated and erupt a luminous head that can reach the size of a planet, spewing gases and dust.
• When this dust burns off, it leaves behind what appears to us on Earth as a trail of light from a distance.
• As a result, comets are frequently observed emitting blue, white, or even green light.

Regarding Green Comet:

• Astronomers in the US just made the discovery of the Green Comet in March 2022.
• The comet's head, which glows green and radiates a whitish light behind it, is known as the "Green Comet" (often called the tail of the comet).
• The comet is presently departing from the Sun along its own orbit after having already contacted the Sun.
• Diatomic carbon, which are two carbon atoms bonded together, is assumed to be the source of the comet's head's green glow. When stimulated by sunlight UV energy, the molecule emits green light.
• According to reports, the green comet may be just 27 million miles away.
• According to NASA, the comet may be visible with binoculars and telescopes, and it may even be visible with the unaided eye in a clear night sky, from Earth at a distance of 2.5 light minutes.

About Comets

• The solar system formed 4.6 billion years ago, leaving behind these ancient objects.
• NASA estimates that 3,743 comets are currently known as of January 2023.

Composition:

• The Sun is orbited by comets, which are frozen rocky or gas-filled objects consisting of dust and ice. Scientists occasionally refer to comets as filthy snowballs or snowy dirtballs if the comet is composed primarily of ice material rather than stony fragments.
• Orbits: Comets have orbits, just as other celestial bodies.
• Comets with brief periods Most of them managed to escape the solar system. Some can be found in the Kuiper Belt, a vast disc that extends past Neptune's orbit (the eighth and final planet). They orbit the Sun for fewer than 200 years.
• Long-period comets are found in the Oort Cloud, the solar system's most remote region, which is around 50 times farther from the Sun.
• The Oort Cloud is formed like a sphere. The comet with the longest known orbit completes one round of the Sun in excess of 250,000 years.

Immune imprinting

• Recent research suggests that "immune imprinting" may reduce the effectiveness of bivalent boosters.

More on the news:

• With the aim that boosters would offer superior protection against the coronavirus infection compared to the original vaccine, nations like the UK and the US have introduced variant-specific or bivalent boosters.
• Studies have revealed that immunological imprinting, a characteristic of our body, maybe render these new boosters much less effective than anticipated.
• Bivalent energizers: To combat both the Omicron strains and the initial Covid-19 strain, bivalent boosters are created.

About Immune imprinting:

• When exposed to a newer or somewhat different form of the same pathogen, the body has a tendency to repeat its immune response depending on the initial variant it encountered through infection or vaccination. This process is known as immunological imprinting.
• According to a publication in the journal Nature, the phenomenon was first noticed in 1947 when researchers saw that "People who had previously had flu, and were then immunised against the current circulating strain, developed antibodies against the original type they had seen."
• Imprinting is now a common name for what was once called the "initial antigenic sin."
• Working: When our body is initially exposed to a virus, memory B cells are created. These cells circulate in the bloodstream and rapidly manufacture antibodies if the same viral strain re-infects.

How does it function?

• Scientists have come to understand that imprinting serves as the immune system's database throughout time.
• It enables a stronger defence against recurrent infections.
• When a virus enters our body for the first time, memory B cells are created. These cells circulate in the bloodstream and rapidly manufacture antibodies if the same viral strain re-infects.

Are the booster doses totally ineffective?

• There is some protection against the new strain provided by these cross-reactive antibodies.
• They are not as powerful, though, as the ones the B cells made when the body first encountered the original virus.

How may immunological imprinting be avoided?

• Several ongoing investigations are now looking for a solution to imprinting.
• Some scientists have suggested that nasal vaccines may be more effective than injection-based ones at preventing illnesses.
• Even if the mucous membranes have some remnants of previous exposure, they think they would provide stronger protection.
• Additionally, scientists are examining if giving annual intervals between coronavirus vaccinations could lessen the issue of imprinting.

Problem:

• When the body comes into contact with a comparable but distinct variant of the virus, a problem arises.
• In such circumstances, the immune system activates memory B cells instead of producing new B cells, which in turn make cross-reactive antibodies—antibodies that bind to characteristics shared by both the old and new strains.
• Although some defence against the new strain is provided by these cross-reactive antibodies, they are not as potent as the ones created by the B cells when the body first encountered the original virus.

Solutions for immunological imprinting:

• Nasal vaccines: According to some experts, nasal vaccines may be more effective than injection-based ones at preventing illnesses.
• Even if the mucous membranes have some remnants of previous exposure, they think they would provide stronger protection.
• The issue of imprinting may be resolved by spacing out vaccinations. For example, coronavirus vaccine injections may be spaced out annually.
• The development of so-called pan-sarbecovirus vaccines, which will provide protection against all COVID-causing variations and perhaps even more SARS and related viruses, is another area of intense research.

Risk of Switching to Clean Energy from Fossil Energy

• According to a study recently published in the journal Global Environmental Change, India's banking sector is extremely vulnerable to the risks associated with the country's economy shifting from being heavily dependent on fossil fuels to clean energy.

What has been discovered?

Change can have a negative impact on:

• As a result of its strong exposure to fossil fuel-related activities, India's banking sector will be negatively impacted by any switch to clean energy.
• The extraction of oil and gas accounts for 60% of credit to the mining industry.
• Petroleum refining and allied businesses account for 20% of the debt in the manufacturing sector.
• The main source of carbon emissions, which accounts for 5.2% of total outstanding credit, is electricity production.
• Experts are in short supply, making it difficult for India's financial institutions to give the institutions the proper advice on the switch from dirty to clean energy.
• Only four out of the ten largest financial institutions assessed gather data on environmental, social, and governance (ESG) issues and these companies do not consistently use that knowledge in financial planning.

Reduced Ability to React to Shocks and Stress:

• 10% of the total debt owed to Indian financial institutions is from high-carbon businesses like power generating, chemicals, iron and steel, and aviation.
• These industries have less financial capacity to respond to shocks and stressors since they are also deeply indebted.
• This will increase the risk that the transformation poses to India's financial sector.

More Polluting and More Expensive Energy Supply:

• The financial decisions of Indian banks and institutional investors are locking the country into a more polluting, more expensive energy supply.
• For example, only 17.5% of bank lending to the power sector has been to pure-play renewables.
• Consequently, India has much higher electricity from carbon sources than the world average.
• Coal currently accounts for 44% of India’s primary energy sources and 70% of its power(electricity).
• The country’s coal-fired power plants have an average age of 13 years and India has 91,000 MW of new proposed coal capacity in the works, second only to China.
• According to the Draft National Electricity Plan 2022, coal’s share in the electricity generation mix will decrease to 50% by 2030.
• It is possible that India's financial industry is significantly exposed to potential transition risks based on present lending and investment patterns.
• The enormous possibility to direct financial resources toward sustainable assets and activities, on the other hand, is the flip side of dangers.

India pledged to achieve net-zero emissions by 2070 in 2021.

• India has also stated that it intends to meet 50% of its electricity demands using non-fossil fuel sources by the year 2030.
• To satisfy these obligations, finance in the range of at least a trillion dollars will be needed.

M1 Abrams & Leopard 2 tanks

About M1 Abrams:

The US President recently declared that he would dispatch M1 Abrams tanks to Ukraine.

The M1 is the best tank in the world because it combines four essential characteristics:

• more mobility to reach targets and avoid attacks
• better controllers and sensors to find and attack targets
• more firepower to obliterate targets
• superior defences to fend off attacks.

Naming:

• The M1 Abrams is named in honour of the late General Creighton W. Abrams, who oversaw the 37th Armored Battalion and served as Army Chief of Staff.
• Because of its powerful firepower and stealthy operation, the M1 is sometimes referred to informally as "The Beast," "Dracula," and "Whispering Death."
• General Dynamics provided the U.S. Army with the first M1 Abrams combat tanks in 1980, but it wasn't until 1991's Operation Desert Storm that the world truly understood the potential of the weapon.
• All but 18 of the almost 2,000 M1s that the American Army and Marine Corps sent to the Persian Gulf were recovered in operational condition.

About Leopard 2 tank:

The German government announced that 14 Leopard 2 tanks will be sent to Ukraine.

• The Leopard 2, which is deployed by many European nations, is less fuel-intensive and easier to maintain than certain western equivalents.

• Beginning in 1970, the Leopard 2 Main Battle Tank (MBT) was developed.
• Leopard 2's initial prototypes were finished in 1972.
• The Leopard 2 was adopted by the West German army in 1979 when the first batch of 30 tanks in production was finished.
• A Rheinmetall RH-M-120 120 mm smoothbore cannon has been mounted on the Leopard 2 main battle tank.
• The Leopard 2 tank's composite armour is comparable to British Chobham. It provides effective defence against anti-tank-guided weapons and bullets that penetrate armour.
• Two 7.62 mm machine guns make up the secondary armament. Another is installed on the top of the roof, while one is coaxial.
• Four people work on the Leopard-2: the commander, the gunner, the loader, and the driver.