1. NITI Aayog vision for Great Nicobar ignores tribal, ecological concerns
Wildlife Board denotifies Galathea bay sanctuary to build port, trade zone
In what appears to a re-run of recent developments in Little Andaman Island (A bullet through an island’s heart, The Hindu, February 1), more than 150 sq. km. of land is being made available for Phase I of a NITI Aayog-piloted ‘holistic’ and ‘sustainable’ vision for Great Nicobar Island, the southernmost in the Andaman and Nicobar group. This amounts to nearly 18% of the 910 sq. km. island, and will cover nearly a quarter of its coastline. The overall plan envisages the use of about 244 sq. km. — a major portion being pristine forest and coastal systems.
Projects to be executed in Phase I include a 22 sq. km. airport complex, a transshipment port (TSP) at South Bay at an estimated cost of ₹12,000 crore, a parallel-to-the-coast mass rapid transport system and a free trade zone and warehousing complex on the south western coast.
What stands out prominently in the whole process, starting with the designation in mid-2020 of the Andaman and Nicobar Islands Integrated Development Corporation (ANIIDCO) as the nodal agency, is the speed and co-ordination with which it has all unfolded. The other is the centrality of the NITI Aayog. First, on September 4, 2020, the Director, Tribal Welfare, A&N Islands, constituted an empowered committee to examine NITI Aayog’s proposals for various projects in Little Andaman and Great Nicobar Islands. A copy of the 2015 ‘Policy on Shompen Tribe of Great Nicobar Island’ was part of the communication sent out, giving an indication of the aims of the committee.
Significant changes have also been effected to the legal regimes for wildlife and forest conservation.
In its meeting on January 5, 2021, the Standing Committee of the National Board for Wildlife (NBWL) denotified the entire Galathea Bay Wildlife Sanctuary to allow for the port there.
The NBWL committee seemed unaware that India’s National Marine Turtle Action Plan that was under preparation then (it was released on February 1, 2021) had listed Galathea Bay as one of the ‘Important Coastal and Marine Biodiversity Areas’ and ‘Important Marine Turtle Habitats’ in the country. It is included in Coastal Regulation Zone (CRZ)-I, the zone with maximum protection.
Then, on January 18, another Environment Ministry expert committee approved a “zero extent” Ecologically Sensitive Zone (ESZ) for the Galathea NP to allow use of land in the south-eastern and south-western part of the island for the NITI Aayog plan. The October 2020 draft notification for this zero extent ESZ had ironically listed out in great detail the park’s ecological uniqueness — that it is part of a UNESCO World Heritage Site, houses a range of forest types, has one of the best preserved tropical rainforests in the world, is home to 648 species of flora and hosts 330 species of fauna including rare and endemic ones such as the Nicobar wild pig, Nicobar tree shrew, the Great Nicobar crested serpent eagle, Nicobar paradise flycatcher and the Nicobar megapode. It also notes that the park is home to the indigenous Shompen community.
The notification says that an ESZ is needed to protect the park from an ecological, environmental and biodiversity point of view, but goes on in the very next para to propose a zero extent ESZ for nearly 70% of the periphery of the park.
It is almost as if the unique diversity of life just listed suddenly disappeared because of an arbitrary line drawn to allow a slew of high value projects.
This is illustrated in the case of the Giant leatherback turtle and the Nicobar megapode, two charismatic species for whom Great Nicobar is very important. The beaches here, like at the mouth of the river Galathea in South Bay are among the most prominent nesting sites globally of the Giant leatherback. It for this reason that the bay was declared a wildlife sanctuary in 1997, but has now been denotified to allow for the transhipment port.
In his 2007 study of the Nicobar megapode, the globally endangered bird unique to the Nicobars, K. Sivakumar of the Wildlife Institute of India documented 90% of this ground nesting bird’s nests to be within a distance of 30 m from the shore. He notes that the existing protected area network in Great Nicobar is not designed for the protection of the megapode and recommends that the entire west and southern coast of Great Nicobar – precisely the area sought for the NITI Aayog proposals – be protected for the megapode and other wildlife like nesting marine turtles. This is also in stark contrast to the current move to create a zero extent ESZ for the Galathea National Park.
Threat to Shompen
Similar concerns exist about the impact on the Shompen community. The proposed project areas are important foraging grounds for this hunter-gatherer nomadic community and the official Shompen Policy of 2015 specifically noted that the welfare and integrity of these people should be given priority “with regard to large-scale development proposals in the future for Great Nicobar Island (such as trans-shipment port/container terminal etc.)”. Now, large forest areas here could become inaccessible and useless for the Shompen.
Available evidence suggests that issues of the geological volatility of these islands are also not being factored in. The December 26, 2019, tender document by WAPCOS Limited for a ‘Traffic Study for Creating Transshipment port at South Bay, Great Nicobar Island’ justifies the port here by noting that “the topography of the island is best suited, which has not been damaged much even by the tsunami on 26.11.2004 (sic)”.
Yet, a 2005 Earthquake Engineering Research Institute (EERI) Special Earthquake Report by a multi-disciplinary team from the Indian Institute of Technology (IIT) Kanpur, recorded witness accounts of 8-metre-high tsunami waves hitting the Great Nicobar coast on December 26, 2004. “The lighthouse at Indira Point, the southernmost tip of the Great Nicobar Island, which was on high ground before the earthquake,” the report notes, “is now under water, indicating a land subsidence of about 3-4 m.”
Loss of life and property then was limited because the Great Nicobar coast is largely uninhabited. This raises questions over safety of life, property and the investments in this zone and that too without accounting for the complex ecological, social and geological vulnerabilities here. Little, if anything, is also known of the NITI Aayog vision document itself – What is its rationale? What was the process of its creation? Which agencies/individuals were involved? What impact assessments, if any, have been done at all?
Neither the NITI Aayog nor the agencies that are facilitating it with zeal have made this available.
(Pankaj Sekhsaria has been researching issues of the Andaman and Nicobar Islands for over two decades. He is also author of five books on the islands.)
Demographics of Andaman and Nicobar islands
- The Andaman Island has dived into four different regions namely North, Middle, South and Little Andaman.
- The four major tribes of Andaman are as follows
- Great Andamanese –Strait Island is the part of North and Middle Andaman district which is the home to Great Andamanese tribe, Fewer than 50 Great Andamanese are alive today.
- Jarawa – South Andaman and Middle Andaman Islands is inhabited by the Jarawa tribes, there are only 300-400 people of this community alive today.
- Sentinelese –North Sentinel Island is part of North Andaman region which is home to the Sentinelese tribe, only 50-100 tribes are alive today.
- Onge – The Little Andaman Island is home to Ongetribes, these tribes are fewer than 100.
- Apart from there are nine Nicobar Islands that are home to Particularly Vulnerable Tribal Groups (PVTGs).
What are the characteristic features of Andaman and Nicobar tribes?
- Race – The Andaman tribes including the Sentinelese are Negrito, where the Nicobar tribes are Mongoloid.
- The A&N tribes are short staturepossibly due to the “island effect” that causes genetic limitation over time.
- Habitat –The Sentinelese are a pre-Neolithic people who have inhabited North Sentinel Island for an estimated 55,000 years without contact with the outside world.
- The reclusive Sentinelese still hold their tiny fort and all remain animistic in faith.
- What makes these tribes special is that they are protected by coral reefs that make landing on their island dangerous, and by the tribe’s unwavering hostility towards outsiders.
- Occupation – Seafaring, Hunting, Forest dwelling are the predominant occupation of these tribes.
- In recent times most tribes have abandoned hunting-gathering and depend entirely on government help.
What are the problems faced by Andaman and Nicobar tribes so far?
- Intrusion – Missionaries had greater success on the Nicobar Islands to the south, which lie on the ancient marine trade route between Europe and the Far East.
- But missionaries have been historically unwelcome in the Andamans, and the tribes of the Islands have resisted every occupation force with bows and arrows.
- Even recently an American missionary was killed by Sentinelese tribes in north sentinel Island when he violated the law and tried to contact the tribes.
- Diseases – Due to their isolation it is unlikely the Sentinelese have immunity against even common diseases.
- A large chunk of the population of the 10 Great Andamanese tribes was wiped out after the indigenous peoples caught syphilis, measles, and influenza on an epidemic scale following contact with the early settlers.
- Natural Disasters – The habitats of the A&N tribes are prone to natural disasters like tsunami and earth quakes.
- Global warming has a high toll on this poor tribes, who are less resilient to recent climatic changes.
- Developmental Projects – When NH 223 was being built in the 1980s, the Jarawa repeatedly attacked workers, the state power-fenced the construction site, and several tribal were electrocuted.
- In recent times local touts and policemen conducting human safaris on NH 223 that cuts through the Jarawa reserve.
- The highway continues to bring the world and sexual exploitation, substance abuse and disease into their shrinking sanctuary.
What are the measures taken by government in this regard?
- The Sentinelese and other aboriginal tribes of the archipelago are protected under The Andaman and Nicobar (Protection of Aboriginal Tribes) Regulation, 1956.
- According to the regulations,
- Traditional areas occupied by the tribes are declared as Reserves.
- It prohibited entry of all persons to reserves except those with authorization.
- Photographing or filming the tribe members is also an offence.
- Under the Foreigners (Restricted Areas) Order, 1963, the Andaman & Nicobar Islands are a “Restricted Area” in which foreigners with a restricted area permit (RAP) can stay on 13 islands, and make day visits to another 11.
- The government gave up in the mid-1990s, and in order to safeguard their health and sovereignty, decided that no one could enter a 5-km buffer zone around their island, which was already out of bounds.
- Between 1998 and 2004, when the Jarawa started to respond to the state, all government hospitals bordering their reserve opened special wards to treat them for infections.
- In 2014, the A&N administration announced a change of policy from “hands off” to “hands off but eyes on” to protect the Sentinelese.
What are the issues with government’s measure?
- In recent years, the Andaman Chamber of Commerce and Industry and the Andaman Association of Tour Operators have pressed to have the RAP restrictions relaxed.
- In 2018, the Home Ministry dropped the RAP requirement for visiting 29 inhabited islands until 2022.
- Even though “separate approvals continue to be required for visiting Reserve Forests, Wildlife Sanctuaries and Tribal Reserves.
- But this move compromised the safety of the tribes and ecology of the islands.
- Following this the UT Administration clarified that Indian nationals would continue to require a pass issued by the Deputy Commissioner for entering a tribal reserve.
- Apart from this foreigners would need prior approval from the Principal Secretary (Tribal Welfare), from various instances it is found that these rules are being compromised.
2. Detecting the unified call of black holes
Gravitational waves from distant events may form a constant background signal
Since the first detection of the merger of black holes dated September 14, 2014, by the two gravitational wave detectors at LIGO in the U.S., the field has witnessed important developments. The LIGO detectors have been joined in their search for gravitational waves from various sources by the VIRGO detector in Italy and the KAGRA detector in Japan. The Indian detector LIGO India is being developed and is expected to join these in their search. In the meantime, Indian scientists have been involved in many aspects of the research and data analysis, especially in gravitational wave radiometry, which is a way to measure gravitational waves from hitherto unknown sources and detect their presence in the sky.
Until now, the number of mergers detected by LIGO, VIRGO and KAGRA detectors is minuscule compared with the number of mergers actually taking place in the sky. The idea that the gravitational waves arising from the collection of all these mergers should be present like a background signal has been around for some time. As suggested by Sanjit Mitra of IUCAA Pune, who has worked in this area, take the analogy of people watching a football game: When you observe individual members among the spectators, you can see their actions, hear their comments etc. But when you look at the crowd as a whole, you may observe the roaring sound of the applause and the cheering which is quite different from observing individuals. The background gravitational waves are like watching the stadium from far, while detections made by the detectors so far has been like observing individuals. Dr. Mitra and a team of researchers have contributed significantly to building up an algorithm that is geared to detect such a so called stochastic gravitational wave background. Their recent work has been published in Physical Review D.
Just as studying the cosmic microwave background tells us about the early universe, its formation, the stochastic gravitational wave background would reveal the structure of the universe around us. Detections till now have been of events that were relatively close to us. Distant binary coalescences, milli-second pulsars, etc are expected to produce a background, and detecting any of this would be a great breakthrough.
The radiometer algorithm which Indian researchers played a key role in developing, comes in useful as a tool for detecting hitherto unknown sources: with recent algorithms developed in India, the radiometer analysis has been made hundreds of times faster and they are now being used by the international collaboration for the official analysis.
The gravitational wave background consists of an isotropic component and an anisotropic component. The isotropic component is constant when you look in different directions and the anisotropic component depends on the direction.
The present results are not that the isotropic component has been detected, we are still far from that, but that the group has successfully shown that it must be below a certain level as otherwise it would have been detected. Future improved versions of the detectors will have to work below this level to detect the background.
“If the gravitational wave background is discovered, it will be a major discovery in astronomy, probably one of the most celebrated ones,” says Dr.Mitra.
- A black hole is an object in space that is so dense and has such strong gravity that no matter or light can escape its pull. Because no light can escape, it is black and invisible.
- There’s a boundary at the edge of a black hole called the event horizon, which is the point of no return — any light or matter that crosses that boundary is sucked into the black hole. It would need to travel faster than the speed of light to escape, which is impossible.
- Anything that crosses the event horizon is destined to fall to the very centre of the black hole and be squished into a single point with infinite density, called the singularity.
If black holes are invisible, how can we detect or photograph them?
- By looking for the effects of their extreme gravity, which pulls stars and gases toward them.
- Also, while anything past the event horizon is invisible, outside that boundary there is sometimes a spiral disk of gas that the black hole has pulled toward — but not yet into — itself.
- The gases in that accretion disk are heated up as they accelerate toward the black hole, causing them to glow extremely brightly. The colours they glow are invisible to us, but are detectable with an X-ray telescope.
- Scientists have also detected the gravitational waves generated when two black holes collide. light surrounding the black hole right to the edge of the event horizon, which is the goal of the Event Horizon Telescope.
How big are black holes?
Small black holes are called stellar-mass black holes. They have masses similar to those of larger stars — about five to 20 times the mass of the sun. The other kind is supermassive black holes, which are millions to billions of times more massive than the sun. That’s the kind the Event Horizon Telescope has been trying to photograph, as bigger objects ought to be easier to see. There is some evidence that black holes between these two sizes exist, but that has yet to be confirmed.
While black holes are very massive, that doesn’t mean they take up a lot of space. Because they’re so dense, they’re actually quite small. According to NASA, a black hole 20 times the mass of the sun could fit inside a ball 16 kilometres wide — the width of the Island of Montreal at its widest point.
Where are black holes found?
Supermassive black holes are found at the centre of most galaxies, including our own Milky Way. The one in our galaxy is called Sagittarius A* and is one of those the Event Horizon Telescope has been attempting to photograph.
Sagittarius A* isn’t the only black hole in our galaxy, though. Earlier this year, astronomers discovered another 12 within three light-years of it, suggesting there could be upwards of 10,000 black holes around the galactic centre.
Where do black holes come from?
Supermassive black holes are believed to form at the same time as the galaxy that surrounds them, but astronomers aren’t sure exactly how.
Stellar mass black holes form when a star with a mass greater than three times that of our sun runs out of fuel. It explodes into a supernova and collapses into an extremely dense core that we know as a black hole — something predicted by Albert Einstein’s general theory of relativity.
Einstein’s theory also predicts the size and shape of the black holes that the Event Horizon Telescope is trying to photograph.
3. Indian monsoon 25 million years ago resembled present day Australia’s
Four fossil assemblages helped to study the climate during 65, 57, 54, and 25 mya
About 180 million years ago, India separated from the supercontinent Gondwana and took a long northward journey of about 9,000 km to join Eurasia. The subcontinent moved from the southern hemisphere, crossed the Equator to reach its current position. Due to these changing latitudes, it experienced different climatic conditions, and a new study has now tried to map these variations using leaf fossils.
“The evolution of the monsoonal climate in India is still debatable and not fully understood. Though recent data indicates that the monsoon system we experience now dates back to about 25 million years, it is still unclear how the climate was during its long voyage,” says Gaurav Srivastava from Birbal Sahni Institute of Palaeosciences, Lucknow, corresponding author of the paper published in Gondwana Research.
The team analysed the morphological characters of fossil leaves collected from Deccan Volcanic Province, East Garo Hills of Meghalaya, Gurha mine in Rajasthan and Makum Coalfield in Assam. The four fossil assemblages were found to be from different geological ages and helped to study the climate during 65, 57, 54, and 25 million years ago. “It has been observed from across the globe that plant leaf morphological characters such as apex, base and shape are ecologically tuned with the prevailing climatic conditions to adapt for all the seasons throughout the year. We applied this model to characterise the past monsoon from fossil leaves,” explains Dr. Srivastava.
The results indicated that the fossil leaves from India were adapted to an Australian type of monsoon and not the current Indian monsoon system during its voyage. The reconstructed temperature data show that the climate was warm (tropical to subtropical) at all the studied fossil sites with temperatures varying from 16.3–21.3 degrees C. All the fossil sites experienced high rainfall, which varied from 191.6 cm to 232 cm.
Dr. Srivastava explains that since India was the only subcontinent to have crossed from the southern hemisphere to the northern hemisphere, it is a laboratory to study biogeo changes and understand how the flora and fauna changed accordingly.
“Our future plan is to better understand the evolutionary history of Indian monsoon and its role in the evolution of biodiversity hot spots in South and Southeast Asia. This will help in the conservation of modern biodiversity hot spots. Understanding the past dynamics of Indian monsoon will also help in climate modelling for future monsoon prediction,” he adds.
- Continents cover 29 per cent of the surface of the earth.
- Observe the shape of the coastline of the Atlantic Ocean. You will be surprised by the symmetry of the coastlines on either side of the ocean. No wonder, many scientists thought of this similarity and considered the possibility of the two Americas, Europe and Africa, to be once joined together.
- It was Alfred Wegener – a German meteorologist who put forth a comprehensive argument in the form of “the continental drift theory” in 1912.
- This was regarding the distribution of the oceans and the continents.
- According to Wegener, all the continents formed a single continental mass and Mega Ocean surrounded the same.
- The super continent was named Pangaea, which meant all earth.
- The mega-ocean was called Panthalassa, meaning all water.
- He argued that, around 200 million years ago, the super continent, Pangaea, began to split.
- Pangaea first broke into two large continental masses as Laurasia and Gondwanaland forming the northern and southern components respectively.
- Subse-quently, Laurasia and Gondwanaland continued to break into various smaller continents that exist today.
- A variety of evidence was offered in support of the continental drift. Some of these are given below.
Evidence in Support of the Continental Drift
The Matching of Continents (Jig-Saw-Fit)
- The shorelines of Africa and South America facing each other have a remarkable and unmistakable match.
- It may be noted that a map produced using a computer programme to find the best fit of the Atlantic margin was presented by Bullard in 1964.
- It proved to be quite perfect. The match was tried at 1,000-fathom line instead of the present shoreline.
Rocks of Same Age across the Oceans
- The radiometric dating methods developed in the recent period have facilitated correlating the rock formation from different continents across the vast ocean.
- The belt of ancient rocks of 2,000 million years from Brazil coast matches with those from western Africa.
- The earliest marine deposits along the coastline of South America and Africa are of the me Jurassic age.
- This suggests that the ocean did not exist prior to that time.
- It is the sedimentary rock formed out of deposits of glaciers.
- The Gondawana system of sediments from India is known to have its counter parts in six different landmasses of the Southern Hemisphere.
- At the base the system has thick tillite indicating extensive and prolonged glaciation.
- Counterparts of this succession are found in Africa, Falkland Island, Madagascar, Antarctica and Australia besides India,
- Overall tesemblance of the Gondawana type Sediments clearly demonstrate that these landmasses had remarkably similar histories.
- The glacial tillite provides unambiguous evidence of palaeoclimates and also of drifting of drifting of continents.
- The occurrence of rich placer deposits of gold in the Ghana coast and the absolute absence of source rock in the region is an amazing fact.
- The gold bearing veins are in Brazil and it is obvious that the gold deposits of the Ghana are derived from the Brazil plateau when the two continents lay side.
Distribution of Fossils
- When identical species of plants and animals adapted to living on land or in fresh water are found on either side of the marine barriers, a problem arises regarding accounting for such distribution.
- The observations that Lemurs occur in India, Madagascar and Africa led some to consider a contiguous landmass “Lemuria” linking these three landmasses,
- Mesosaurus was a small reptile adapted to shallow brackish water.
- The skeletons of these are found only in two localities: the Southern Cape Province of South Africa and Iraver formations of Brazil.
- The two localities presently are 4,800 km apart with an ocean in between them.
4. The emerging crisis of obtaining helium in India
Every year, India imports helium worth ₹55,000 crore from the U.S.
Helium is colourless, odourless, tasteless, inert and a noble gas. Yet, it finds many applications, mainly in magnetic resonance imaging (MRI) scans, in rockets and in nuclear reactors. India imports helium for its needs, and with the U.S. appearing set to cut off exports of helium since 2021, Indian industry stands to lose out heavily. What is the solution? Can India become self-reliant towards its needs of helium gas?
Helium on Earth
Dutch physicist Kamerlingh Onnes liquefied Helium by cooling the gas to -270 degrees Celsius. It is known that Kamerlingh Onnes collected helium gas from the springs of Bath in Baden Baden, Germany for his liquefaction experiment.
Some scientists and geologists started looking for helium underground – they guessed it may be present there by analysing debris from volcanic eruptions. From the oil drilling operation in Dexter, Kansas, in the U.S., chemists Hamilton Cady and David McFarland discovered the presence of helium in natural gas. They further went on to discover that despite its overall rarity, helium was concentrated in large quantities under the American Great Plains.
The U.S. became the most important exporter of helium across the world. It was soon realised that U.S. was also the biggest store house of helium.
The U.S., now, is planning to switch off export of helium from 2021. Qatar is a possible exporter but acute political and diplomatic wrangles have made Qatar unreliable.
Every year, India imports helium worth Rs 55,000 crores from the U.S. to meet its needs.
Around 1956, as vice chancellor of Viswabharati University, Professor Satyendranath Bose once visited a village called Bakreswar (near Santiniketan) where he found water boiling naturally in a small tank. Satyen Bose was keen to analyse the natural gas that came out of the tank.
Satyen Bose asked his student Shyamadas Chatterjee to look into this. What Shyamadas Chatterjee found out was stunning: 1.8% of the natural gas emanating from the boiling water was helium. After further experiments, this result was established.
Shyamadas Chatterjee’s hunch was that the area called Rajmahal volcanic basin around Bakreswar and nearby Tantloi, now in Jharkhand, were floating on an ocean of helium.
He and his student Debasis Ghose started exploring Tantloi, which is populated by tribal people. The village is situated next to a stream, with naturally hot water with natural gas emanating from it. Preliminary investigations of the stream indicated there was around 1.6% of helium in the emanating gas, a little less than that in Bakreswar. This was around (1965-66).
Homi Sethna, then the Chairman of the Atomic Energy Commission arranged for the project to be part of the newly started Variable Energy Cyclotron Centre (VECC) project of Kolkata.
When I came over to Kolkata around 1984 to VECC from BARC, Bombay the helium project did not show much activity. The adventure of it all attracted me. I persuaded Dr. Divatia then the director of VECC to take a trip to Bakreswar along with Professor Chatterjee and Dr. Ghose.
It should be mentioned that Bhabha Atomic Research Centre under the leadership of R. K. Garg, head of the Chemical and Engineering Division, in the 1970s made an effort to extract helium from monazite sand. Unfortunately, this project was doomed, and BARC did not push it any further.
When we took over the project in late 1980s we got very busy with other research and development projects. We all thought collection of helium on a large scale is a semi-commercial operation and nothing very much to do with research or development. Besides which, we just did not have the adequate man power.
So, this vast reservoir of helium in the Rajmahal volcanic belt remained untapped.
Extracting helium on a large scale did not seem to be of great importance to our scientific fraternity. After I stepped down from my official job in 2009, the possibility of helium extraction looked even more bleak. Then, I found a very understanding and enthusiastic person in the present chairman of Atomic Energy Commission, Dr. K. N. Vyas, who readily agreed to give the project a push with all the might of the Department of Atomic Energy (DAE).
Work has started in right earnest in collaboration with Atomic Mineral Division of DAE. Preliminary measurements and survey have already started.
Our target is to at least meet India’s requirement of helium. India consumes about 70 million cubic metres per year. But the reserve of helium by far exceeds this.
So, this effort although somewhat late is not too late yet!
India’s Rajmahal volcanic basin is the store house of helium trapped for billions years, since the very birth of our Earth from the Sun. At present, we are mapping the Rajmahal basin extensively for future exploration and harnessing of helium.
In conclusion, helium is not just for ballons but it is the key ingredient for India’s high technology and the most sophisticated medical diagnosis.
(Dr Bikash Sinha is an
INSA senior scientist and former director of Saha Institute of Nuclear Physics and Variable Energy Cyclotron Centre, Kolkata)
Helium, the lightest of the noble gases, had actually been detected and helium is the only element in the periodic table that was discovered by an astronomer.
- Helium is the element which you can find on the upper right side of the periodic table with atomic number 2. It comes first amongst the family of the noble gases.
- It holds one atomic orbital and was named by Lockyer and Frankland. Its name is derived from the Greek word “Helios” meaning Sun. Scientists knew there is an enormous amount of helium in the Sun before it was discovered.
- Helium falls under inert gas since its outermost electron orbital is full of two electrons. Helium can also be found in lasers, compressed air tanks and coolant in nuclear reactors.
- It holds the lowest boiling and melting points amongst the all other elements. The Nuclear fusion of hydrogen in stars generates a significant amount of helium.
Helium has two known stable isotopes – 3He and 4He. The abundance of helium-3 and helium-4 corresponds to 0.0002% and 99.9998% respectively. This difference in abundances can be observed in the Earth’s atmosphere, where the ratio of 4He atoms to 3He atoms is approximately 1000000:1.
Physical Properties of Helium
|Helium (He)||Physical Properties|
|Melting Point||0.95 K (or -272.2oC)|
|Boiling Point||4.222 K (or -268.928oC)|
|Density||0.1786 g/L at STP; 0.145 g.cm-3 at its melting point|
|Critical Temperature and Pressure||5.195 K; 0.227 MPa|
|Triple Point||2.177 K; 5.043 kPa|
|Appearance (at STP)||Colourless gas|
Chemical Properties of Helium
|Helium (He)||Chemical Properties|
|First Ionization Energy||2372.3 kilojoules per mole|
|Second Ionization Energy||5250.5 kilojoules per mole|
|Van der Waals Radius||140 picometers|
|Enthalpy of Fusion||0.0138 kilojoules/mole|
Uses of Helium
- The primary use of Helium goes in altitudes research and meteorological balloons.
- It is utilized as an inert protective gas in autogenous welding.
- It is the only cooler capable of declining temperature lower than 15K (-434ºF).
- Helium is also used in the production of germanium crystals and silicon crystals.
- Since it has the ability to diffuse through solids much faster than air, helium is used industrially for pipeline leak detection.
- This element is also used in gas chromatography as a carrier gas.
- Owing to its low melting point, liquid helium has numerous applications in cryogenics, magnetic resonance imaging (MRI), and superconducting magnets.
5. ‘Both vaccines are effective, but a comparison is months away’
AIIMS Director says they could provide protection for ‘eight months to one year’
The government held an emergency meeting on Friday amid reports of clotting of blood in some patients in Europe who had received shots of the Oxford-AstraZeneca vaccine, and it was concluded that no such problem had been reported in India, said N.K Arora, head of the operations research group of the Indian Council of Medical Research’s National Task Force for COVID-19, in an online interaction with Indian Police Service (IPS) officers on Saturday.
Dr. Arora said that the finding from India had been shared with the World Health Organization (WHO), and that most European countries had restarted their vaccination programme. He claimed that, overall, if 10,000 people were vaccinated, then adverse symptoms such as fever, swelling, redness and pain were reported only in 40.
“Yesterday [Friday], 97.5% of the people who developed symptoms (post vaccination), had these adverse effects. So overall, among 10,000, only 40 were having significant symptoms… I am using these figures as I am talking to an illustrious group. Adverse symptoms are uncommon. We have given 4 crore injections, [and] have not lost individuals because of severe events,” Dr. Arora said.
V.K. Paul, Member, NITI Aayog, who participated in the interaction, said that the incidence of AEFI (adverse events following immunisation) was minimum, at 0.05% . The virtual meeting on COVID-19 vaccination was organised by the IPS (Central) Association and moderated by senior IPS officer Aditya Mishra.
At least two IPS officers sought to know which of the two vaccines was more effective. Randeep Guleria, Director, AIIMS, said that it would be months before a comparison could be made, but both vaccines were equally effective.
“Covaxin uses inactive platform and Covishield uses virus vector platform to put spike protein in [the] body. Currently, both [are] given through intramuscular route….both vaccines produce good amount of antibodies…We should take the vaccines available to us. It would be many months [before] we could compare A to B, but they are more or less equally effective. Considering we have to vaccinate large number of people, both have been approved,” Dr. Guleria said.
He said the vaccines could provide protection for “at least eight months-one year” and even longer, but it would depend on how the virus behaved and how the protection evolved for different populations.
Dr. Arora said that 30% of people infected by COVID-19 may not develop antibodies, and if they took the vaccines, it would act as a booster.
“Pregnant women and children below 18 years are not to be given the vaccines for lack of scientific study so far. Individuals suffering from hypertension, diabetes, cancer, heart disease, or those who are on blood thinners, can get the vaccine…those who are taking cancer drugs and suffering from auto immune disorder, even they can take it.Take the vaccine at topmost priority,” Dr. Arora said.
Dr. Paul said the supply of vaccines was limited and they had to be given to people who need them the most. “78% deaths are among people above 50 years,” he said, adding that the police could play a role in enforcing COVID-19 appropriate behaviour.
Antibodies are not found at a place as such, but whenever our immune system encounters antigen or a pathogen, B cells get activated immediately releasing antibodies into the bloodstream. These immunoglobulins undergo mitosis resulting in cell division and continuously produce antibodies as a result of producing more cells. These antibodies remain in the blood for some time but B cells remember these antigens and repeat the same course of action whenever they reappear in our body.
What are Antibodies?
Antibody (Ab) is also known as an immunoglobulin(Ig). These are large, Y-shaped blood proteins produced by plasma cells. They bind to foreign particles and invade them. These particles are foreign bodies that get attacked by Antibody.
Antigens are foreign pathogens that invade the body and have the capability to give rise to a response from our immunity system either by grouping up with a larger molecule or alone after binding with antibodies for a particular immune response. Hence, antigens stimulate the production of antibodies by the immune system.
An antibody has a Y-shaped structure, made up of four polypeptide subunits. Each subunit has two identical light and heavy chains.
The N-terminus of each heavy chain forms an antigen-binding domain with a light chain. There are two antigen-binding domains forming the arms of the “Y” shape. They are known as ‘fragment antigen-binding’ (Fab) domains.
The C-terminus of the heavy chains forms ‘fragment crystallization’ (Fc) domain, which helps in the interaction with the effector cells.
All four polypeptide subunits are held together by disulfide and non-covalent bonds.
The heavy chains of the antibodies contain a variable region and three constant regions. Each antibody has two identical antigen-binding sites and they differ in the antibodies.
Types of Antibodies
Antibodies or immunoglobulins (Ig) are of five different isotypes. This classification is on the basis of their H chains. The different types of antibodies are:
- IgM is the first antibody produced in response to a microbial attack by B cells.
- It is the largest antibody and is found in a pentameric form.
- It circulates in the blood and lymph and constitutes 6% of the total antibody content in the serum.
- It is involved in agglutination and opsonization.
- It has a large number of antigenic sites on its surface and therefore facilitates efficient activation of the immune system.
- Most abundant isotype in the plasma, and comprises 80% of the total antibody content in the serum. It detoxifies substances that are harmful and recognizes the antibody-antigen complex.
- It is transferred to the placenta through the foetus and protects the infant until its birth.
- IgG is divided into four subclasses- IgG1, IgG2, IgG3, and IgG4. Among these, only IgG3 and IgG4 possess the ability to cross the placenta.
- The heavy chains of IgG have two antigen-binding sites and are of the sub-class gamma.
- It facilitates the process of phagocytosis and provides immunity to the developing foetus. It neutralizes the toxins and pathogens and offers protection to the body.
- Usually found in liquids such as breast milk, serum, saliva, fluids of the intestine. IgA in breast milk protects an infant’s gastrointestinal tract from microbial activity.
- It constitutes 13% of the total antibody content in the serum and is divided into 2 sub-classes- IgA1 and IgA2. Among these, IgA1 is highly found in the secretions and is also called the secretory immunoglobulin.
- It exists in both monomeric as well as dimeric forms.
- It provides the first line of defence against the pathogens and limits inflammation. It also activates the complement pathway and participates in the immune response.
- It is involved in the production of the antibody by B cells.
- It is present as a monomer and weighs around 1,80,000 dalton.
- It comprises less than 1% of the total antibody content in serum.
- It acts as a receptor on B cell surface and participates in B cell activation and differentiation.
- IgE is present in the least amounts, around 0.02% of the antibody content in the serum.
- These are present in the linings of the respiratory and intestinal tracts and respond to allergic reactions.
- This is found as a monomer in the body and weighs about 200,000 Dalton.
Functions of Antibody
Following are some of the key functions of antibody:
- Binds to pathogens
- Activates the immune system in case of bacterial pathogens
- Directly attacks viral pathogens
- Assists in phagocytosis
- Antibody provides long-term protection against pathogens because it persists for years after the presence of the antigen.
- It neutralizes the bacterial toxins and binds the antigen to enhance its efficiency.
- They also act as the first line of defence for mucosal surfaces.
- They ingest cells by phagocytosis.
- Few antibodies bind the antigen present on the pathogens. These aggregates the pathogen and they remain in secretions. When the secretion is expelled out, the antigen is also expelled.
Production and Mechanism Of Antibody
Whenever an organism’s immune system encounters a foreign particle for the first time, macrophages interfere and capture to break them down so as to pass them to B cells. Once these antigens are presented, B cells begin production of a new antibody which would contain a unique paratope (site at which antibody binds with antigen) to bind with a specific epitope (site in the antigen that binds with antibody). Each lymphocyte of B cells generates a unique antibody against a unique epitope. Once the encoding is done by B cells, it releases antibodies which then bind with specific pathogens resulting in their elimination from our bodies.
This is achieved either by direct attack of antibody on pathogens (usually when pathogens are viruses) or by binding to pathogen’s surface (when the pathogen is a bacteria) and sending signals to the rest of the immune system to eliminate the pathogen. These cells remain in the body forever, ready to attack, should they re-enter the body.
Difference between Antigen and Antibody
|These molecules interact with antibodies or by T-cell receptors when complexed with major histocompatibility complex||Synthesized by plasma cells of B cells that react with antigens who invoked their production|
|Includes components of viral proteins, cell walls, capsules, and other microbes||Consists of 4 polypeptide chains, two light chains(L chain) and two heavy chains(H chain) forming a Y shape|
|These are proteins but can be nucleic acids, carbohydrates and lipids||These are glycoproteins made up of carbohydrates and amino acids|
|Highly complex in structure and composition||Simpler in structure|
|Causes diseases or allergic reactions||Protects the body against diseases|
|The pathogen has many epitopes. Epitopes are regions on antigens that interact with antibodies||The region of an antibody that binds with an epitope is called a paratope. Typically, a Y shaped antibody has 2 identical paratopes|