Hunga Tonga-Hunga Ha’apai

• Hunga Tonga is the short form of Hunga Tonga-Hunga Ha’apai.
• It is an underwater volcano in Tonga Island which is located in Pacific Ocean.
• It erupted on January 2022, in the Pacific Kingdom of Tonga that created a tsunami.
• The tsunami triggered warnings across the entire Pacific basin, and sent sound waves around the globe multiple times.
• The eruption could have effects on the winter weather for years to come.
• Role of sulphur dioxide – Usually, the sulphur dioxide in the smoke of a volcano cools the earth’s surface for a short period.
• This didn’t happen for Hunga Tonga, because it was an underwater volcano.
• Effects of the volcano – Hunga Tonga produced little smoke, but a lot of water vapour.
• The enormous heat of the eruption transformed huge amounts of sea water into steam, which then shot high into the atmosphere with the force of the eruption.
• All that water ended up in the stratosphere layer of the earth.
• Water vapour in the stratosphere has 2 main effects:
  1. It helps in the chemical reactions which destroy the ozone layer
  2. It is a very potent greenhouse gas
• The large ozone hole from August to December 2023 was at least in part due to Hunga Tonga.

Mitral Valve Disease

In a first in Indian subcontinent, a dog with a complex heart condition successfully underwent a minimally invasive heart surgery at Delhi veterinary hospital.

• Mitral valve disease (MVD) is a common type of heart valve disease that occurs when the mitral valve doesn't open and close properly.
• The mitral valve is made of two flaps of tissue, called leaflets or cusps that control the flow of blood from the left atrium to the left ventricle.
• MVD can be classified into 2 types:
  1. Mitral regurgitation (MR)
  2. Mitral stenosis (MS)
• Mitral valve disease can affect all ages of humans.
• Mitral valve regurgitation is a condition where the mitral valve in the heart does not close properly, allowing blood to flow backward from the left ventricle to the left atrium.
• Mitral valve disease in dogs – It is the most common heart condition in dogs in India as well as in rest of the world.
• It accounts for 80% of all heart diseases in dogs in India and worldwide.
• This disease is amongst one of the major causes of deaths in dogs.
• The only treatment majorly available so far includes medicinal treatment which delays the onset of clinical signs and gives symptomatic relief for some time.
• Open heart mitral valve repair surgery is not a very viable option owing to the highly invasive nature of the procedure and because it is done at very few centres in the world.
• Transcatheter Edge-to-Edge Repair (TEER) – Is entirely an image guided procedure and is done under trans oesophageal 4D echocardiography and fluoroscopy guidance in a beating heart.
• It treats valve leakage and mitral regurgitation.
• The procedure is similar in concept to Mitra clip procedure in humans which has benefitted and saved many human lives so far.

Virus-like Particles (VLPs)

Scientists at the Institute of Advanced Virology in Thiruvananthapuram, Kerala, have developed a novel method to generate non-infectious virus-like particles (VLPs) that mimic the Nipah virus (NiV).

• Nipah virus (NiV) is a zoonotic disease that spreads primarily between animals and humans.
• Nipah is a highly pathogenic paramyxovirus, with a fatality rate of up to 80% in affected humans.
• The genome of the NiV encodes 6 major proteins:
  1. Glycoprotein (G)
  2. Fusion protein (F)
  3. Matrix (M)
  4. Nucleocapsid (N)
  5. Long polymerase (L)
  6. Phosphoprotein (P)
• Virus-like Particles (VLPs) – VLPs are molecules that closely resemble viruses, but are non-infectious because they contain no viral genetic material.
• VLPs carry most of the characteristics of the virus, except their ability to replicate (because it lacks the viral genome).
• The advent of NanoBiT technology and “HiBiT-tagged” VLP (HiBiT is an 11 amino acid peptide) makes it far more sophisticated.
• Scientists at the Institute of Advanced Virology (IAV) have generated “HiBiT-tagged” Nipah virus-like particles (NiV-VLPs).
• Highly sensitive and quantitative HiBiT-tagged Nipah virus-like particles is a platform for rapid antibody neutralisation studies.
• It was generated using plasmid-based expression systems, encoding the NiV structural proteins G, F, and M.
• The VLPs produced are morphologically and functionally identical to the native virus.
• The inclusion of a highly sensitive HiBiT tag on these VLPs accelerates their potential in antiviral drug screening and vaccine development.
• Virus neutralisation assays – Are critical for the development and evaluation of vaccines and immune-therapeutics,
• They are also used for conducting basic research into the immune response and pathogenesis of NiV.
• These tests, which traditionally require to be done in high security labs (BSL-4) with the infectious organism, can now be done safely in BSL-2 labs in the country using the NiV-VLPs.
• Biosafety level 4 (BSL-4) laboratories are designed to handle pathogens that are highly contagious and can cause fatal diseases.
• These pathogens are known as Risk Group 4 pathogens and include viruses like Ebola, Lassa, Nipah, Marburg and Crimean-Congo hemorrhagic fever.

Chollima-1

Recently a North Korea's military satellite launch has failed and rocket exploded in Yellow Sea.

• In this mission the North Korea have tried a new "liquid oxygen and petroleum engine" with the rocket which failed during its first stage.
• This rocket is different from the Chollima-1, which is used in previous successful launches by the North Korea.
• The Chollima-1 uses hypergolic fuels that ignite on contact and are typically used in North Korea's nuclear missiles, which do not use liquid oxygen due to storage temperature challenges.
• The new engine type may indicate Russian assistance, as Russia has previously vowed to help North Korea's satellite programme.
• Liquid oxygen engines, like those developed by Russia, require specialised storage and handling due to extremely low boiling points.

Mullaperiyar Dam

Kerala has been seeking a new Terms of Reference from the Ministry of Environment, Forest and Climate Change to conduct an Environment Impact Assessment for constructing a new dam at Mullaperiyar.

• The Mullaperiyar Dam was constructed between 1887-1895 under a 999-year lease agreement between the Maharaja of Travancore and the Secretary of State for India for Periyar irrigation works.
• British raj was the period of direct British rule over the Indian subcontinent from 1858 until the independence of India and Pakistan in 1947.
• In 1979, reports emerged about damage to the Periyar Dam, leading to measures for strengthening the dam and limiting the water level.
• It became a legal dispute, with Kerala passing an act in 2006 prohibiting raising the water level beyond 136 ft, while Tamil Nadu wanted to raise it to 142 ft after strengthening measures.
• The Supreme Court intervened and constituted an Empowered Committee in 2010 to study the dam's safety.
• The Committee concluded in 2012 that the dam is hydrologically safe.
• In 2014, the Supreme Court declared Kerala's 2006 act unconstitutional and directed setting up a Supervisory Committee to monitor the dam's safety after restoring the full reservoir level (FRL) to 142 ft.
• Recent issues – Kerala has been seeking a new Terms of Reference (ToR) from the Expert Appraisal Committee (EAC) of the Ministry of Environment, Forest and Climate Change (MoEF).
• The ToR deals with conducting an Environment Impact Assessment (EIA) for constructing a new dam at Mullaperiyar.
• The earlier ToR issued in 2018 for the same purpose had expired, prompting Kerala to seek a fresh one.
• However, the EAC meeting scheduled for May 28 to consider Kerala's request was cancelled abruptly.
• Tamil Nadu objected to Kerala's move, arguing that it violates the Supreme Court's order which stated that the court's permission is required for any such studies related to a new dam.
• Tamil Nadu maintains that the existing 128-year-old dam has been repeatedly found safe by expert committees and the Supreme Court.