30 SEPTEMBER 2023

Topic 1: OSIRIS-REx and Bennu

Why in news: NASA’s OSIRIS-REx is a robotic spacecraft that has been on a seven-year mission to collect and return samples from an asteroid called Bennu — billions of kilometers from Earth.

About OSIRIS-Rex:

• NASA’s OSIRIS-REx is an ongoing mission that visited and collected a sample from asteroid 101955 Bennu.
• It returned the sample to Earth recently.
• The spacecraft is headed to a new target, the asteroid Apophis, which will also fly close to Earth in 2029.

What is asteroid Bennu?

• Asteroids are rocky objects that orbit the Sun, much smaller than planets.
• They are also called minor planets.
• Bennu is an asteroid about as tall as the Empire State Building, located about 200 million miles away from the Earth.
• Bennu is named after an Egyptian deity.
• The asteroid was discovered in 1999.
• So far, we know that Bennu is a B-type asteroid, implying that it contains significant amounts of carbon and various other minerals.
• Because of its high carbon content, the asteroid reflects about four per cent of the light that hits it, which is very low when compared with a planet like Venus, which reflects about 65 per cent of the light that hits it.
  • Earth reflects about 30 per cent.
• Around 20-40 percent of Bennu’s interior is empty space and scientists believe that it was formed in the first 10 million years of the solar system’s creation, implying that it is roughly 4.5 billion years old.
• There is a slight possibility that Bennu, which is classified as a Near Earth Object (NEO), might strike the Earth in the next century, between the years 2175 and 2199.
  • NEOs are comets and asteroids nudged by the gravitational attraction of nearby planets into orbits which allow them to enter the Earth’s neighbourhood.
• Bennu is believed to have been born in the Main Asteroid belt between Mars and Jupiter and because of gravitational tugs from other celestial objects and the slight push asteroids get when they release absorbed sunlight, the asteroid is coming closer to Earth.

What is a sample return mission?

• Sample return missions tend to be robotic.
• But we have in the past sent humans to collect rocks and soil from space — NASA’s Apollo missions did that between 1969 and 1972.
• Sample return missions send spacecraft to land on a celestial body — a moon, asteroid or planet — and collect samples of soil, minerals and rock.
• The samples are analyzed in laboratories on Earth.

Future missions:

• Japan’s Martian Moons eXploration (MMX) aims to be the first sample return mission to bring back rocks from the Mars region.
• Scheduled to launch in 2024, MMX aims to investigate the moons of Mars, Phobos and Deimos, and gather information on how they formed.

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Topic 2: Conocarpus plants

Why in news: The Gujarat government has banned the planting of ornamental Conocarpus trees in forest or non-forest areas, citing their adverse impacts on environment and human health.

About the plant:

• Conocarpus is a fast-growing exotic mangrove species.
• Conocarpus is a genus of two species of flowering plants in the family Combretaceae, native to tropical regions of the world.
• One of the species is a widespread mangrove species, and the other is restricted to a small area around the southern Red Sea coasts, where it grows alongside seasonal rivers.
• C. erectus is native to the coasts of tropical America from Bermuda.
• C. lancifolius is native to Somalia and Yemen, and is cultivated in eastern and northern Africa and the Arabian peninsula.

Why is it banned:

• Earlier, Telangana too had banned the plant species.
• Research reports have highlighted adverse impacts/ disadvantages of this species on environment and human health.
• Trees of this species flower in winter and spread pollen in nearby areas.
• It is learnt that this is causing diseases like cold, cough, asthma, allergy etc.
• Roots of this species go deep inside the soil and develop extensively, damaging telecommunication lines, drainage lines and freshwater systems.
• It also kills off competition.
  • Within a decade, it had taken over the Delhi Ridge, killing the native trees like acacia, dhak, kadamb, amaltas, flame-of-the-forest, etc.
  • Along with the trees disappeared the fauna — birds, butterflies, leopards, porcupines and jackals.
• The tree also depletes the water table of the area it is planted in.

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Topic 3: Matangini Hazra

Why in news: Recently homage was paid to the valiant Matangini Hazra on her Death Anniversary.

About Mantangini Hazra:

• Matangini Hazra was 73 when she fell to British bullets, leading a protest march in 1942 in Tamluk, Bengal.
• Her death made her a martyr, and one of the earliest casualties of the Quit India movement.
• Matangini Hazra was among the thousands who fell for the charisma and message of the Mahatma, and joined the freedom struggle whole-heartedly.
• At the age of 61, she was arrested for taking part in the Civil Disobedience Movement in 1930.
  • It was during this time that she became an active member of the Indian National Congress, and started spinning her own khadi in Gandhi’s footsteps.
• In 1977, the first statue in the Kolkata Maidan dedicated to a woman revolutionary was that of Matangini Hazra.

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Topic 4: MS Swaminathan and Green Revolution

Why in news: The legendary agricultural scientist Monkomb Sambasivan Swaminathan, 98, passed away recently.

About MS Swaminathan:

• Called the ‘Father of the Green Revolution’, he played a major role in the set of changes introduced in farming in the 1960s and ‘70s that helped India achieve food security.
• Early on in his career, he cleared the examination for the civil services but Swaminathan was interested in agriculture foremost and soon ended up pursuing research in the field.
• He would go on to serve at a number of institutions related to the sector in both India and abroad:
  • as an Independent Chairman of the Food and Agricultural Organisation Council (1981-85),
  • President of the International Union for the Conservation of Nature and Natural Resources (1984-90),
  • President of the World Wide Fund for Nature (India) from 1989-96 and the
  • Director General of Indian Council of Agricultural Research (ICAR).
• For his contributions, Swaminathan was awarded the first World Food Prize Laureate in 1987, for developing and spearheading the introduction of high-yielding wheat and rice varieties into India during the 1960s.

What was the Green Revolution?

• A period of rapid, scientific agricultural advancement in the mid-1960s that involved growing a high-yielding, disease-resistant variety of wheat, primarily in Punjab, was the beginning of India’s Green Revolution.
• Dr. Swaminathan was the key architect of this movement.
• Short-straw or dwarf varieties of crops like rice and wheat formed the basis of India’s Green Revolution.
• Dwarf strains have a higher Harvest Index, which means that the plant puts more of its energy resources into seeds rather than leaves or other plant structures.
  • Harvest Index quantifies the crop yield in comparison to the total biomass produced.

What are high-yielding varieties of crops?

• High-yielding varieties of crops, or HYVs, produced a higher yield of crop per hectare in comparison to traditional variants.
• These variants are produced using a combination of traditional breeding steps and biotechnology, which includes genetic diversity.
• The resulting HYVs are usually disease-resistant and have a higher tolerance to conditions like drought.
• IR8, a variety of rice developed by the International Rice Research Institute (IRRI) that could produce as much as seven tonnes of rice per hectare compared to traditional seeds that could produce only two tonnes per hectare, was one of the main HYVs grown during the Green Revolution.
• Other HYVs grown during the Green Revolution in India included Kalyan Sona and Sonalika varieties of wheat.

Need for Green Revolution and role of Swaminathan

• This was needed because post-independence, Indian agriculture was not very productive. \
• Years of colonial rule impacted its development and the nation lacked the resources to modernise the sector.
• As a result, crops necessary for staple foods also had to be imported from countries like the US.
• The problem with the traditional wheat and rice varieties was that they were tall and slender.
  • These ‘lodged’ – fell flat on the ground — when they grew and their earheads were heavy with well-filled grains produced in response to high fertiliser doses.
• Through Swaminathan’s research on rice, a reduction in plant height was sought to make them less lodging-prone.
• His strategy of developing semi-dwarf wheat varieties using mutagenesisdid not, however, work as the lowering of plant heights led to a simultaneous reduction in the size of the grain-bearing panicles or earheads.
  • Mutagenesis is the process of exposing plants to chemicals or radiation to introduce desirable modifications in their DNA.
• The search for an ideal variety led him to contact American scientist Orville Vogel.
  • He played a role in developing a ‘dwarf wheat’ called Gaines, which had a high yield.
  • It contained dwarfing genes from a dwarf wheat called the Norin-10.
• Swaminathan later approached Norman Borlaug, who had incorporated the same dwarfing genes through Vogel’s lines into his spring wheat varieties in Mexico that were better suited for India.
• Borlaug would also later visit India, after Swaminathan proposed so to the Indian Agricultural Research Institute, allowing for the wheat breeding programme to commence.

The side effects of the Green Revolution

• Pests and Pesticide
  • There has been a significant increase in the usage of pesticides, and India became one of the largest producers of pesticides in the whole of Asia.
  • It is reported that the presence of pesticides within freshwater is a costly concern with detected levels exceeding the set limits of pesticide presence.
  • Although the average amount of pesticide usage is far lower than in many other countries, there is high pesticide residue in India.
  • This causes a large amount of water pollution and damage to the soil.
  • Another major issue is the pest attack, which arises due to an imbalance in the pests.
    • Due to increased pesticide usage, the predator and prey pests are not in balance, and hence there is an overpopulation of one kind of pest that would attack certain crops.
    • This leads to an imbalance in the production of those kinds of crops.
    • This also has led to the disruption in the food chain.
• Water Consumption
  • India has the highest demand for freshwater usage globally, and 91% of water is used in the agricultural sector now.
  • Currently, many parts of India are experiencing water stress due to irrigated agriculture.
  • The crops introduced during the green revolution were water-intensive crops.
  • Punjab is a major wheat- and rice-cultivating area, and hence it is one of the highest water depleted regions in India.
  • Diminishing water resources and soil toxicity increased the pollution of underground water.
• Air Pollution
  • Air pollution introduced due to the burning of agricultural waste is a big issue these days.
  • In the heartland of the green revolution, Punjab, farmers are burning their land for sowing the crops for the next cycle instead of the traditionally practiced natural cycle.
  • The next crop cycle arrives very soon because the crop cycle is of short duration for the hybrid crops introduced in the green revolution.
  • This contributes to the high amount of pollution due to the burning of agricultural waste in parts of Punjab.
  • This kind of cultivation can lead to the release of many greenhouse gases, such as carbon dioxide, methane, nitrogen oxides, etc.
• Impacts on Soil and Crop Production
  • There was a repetition of the crop cycle for increased crop production and reduced crop failure, which depleted the soil’s nutrients.
  • Similarly, as there is no return of crop residues and organic matter to the soil, intensive cropping systems resulted in the loss of soil organic matter.
  • To meet the needs of new kinds of seeds, farmers used increasing fertilizers as and when the soil quality deteriorated.
  • The application of pesticides and fertilizers led to an increase in the level of heavy metals, especially Cd (cadmium), Pb (lead), and As (arsenic), in the soil.
  • Weedicides and herbicides also harm the environment.
  • The soil pH increased after the green revolution due to the usage of these alkaline chemicals.
  • The practice of monoculture (only wheat–rice cultivation) has a deleterious effect on many soil properties, which includes migration of silt from the surface to subsurface layers and a decrease in organic carbon content.
  • Toxic chemicals in the soil destroyed beneficial pathogens, which are essential for maintaining soil fertility.
  • There is a decrease in the yield due to a decline in the fertility of the soil.

• Extinction of Indigenous Varieties of Crops
  • Due to the green revolution, India lost almost 1 lakh varieties of indigenous rice.
  • Since the time of the green revolution, there was reduced cultivation of indigenous varieties of rice, millets, lentils, etc.
  • In turn, there was increased harvest of hybrid crops, which would grow faster. This
  • Traditionally grown and consumed crops, such as millets, grow easily in arid and semi-arid conditions because they have low water requirements.
  • However, there was the unavailability of high-yielding seeds of millets, and hence farmers moved to only rice and wheat.
• Food Consumption Pattern
  • Traditionally, Indians consumed a lot of millets, but this became mostly fodder after the green revolution.
  • The Food and Agriculture Organization (FAO) has recorded that over the years 1961–2017, there are a decrease in the production of millets and an increase in the production of rice.
  • Thus, rice became the staple diet of the country.
  • Though the green revolution made food available to many, it failed to provide a diverse diet but provided increased calorie consumption.
• Health-Related Impacts on the General Population
  • Most of the pesticides used belong to the class organophosphate, organochlorine, carbamate, and pyrethroid.
  • Indiscriminate pesticide usage has led to several health effects in human beings in the nervous, endocrine, reproductive, and immune systems.
  • Of all, the intake of food items with pesticide content is found to have high exposure, i.e., 103-105 times higher than that arising from contaminated drinking water or air.
• Impacts on Farmers
  • Most of the farmers who use pesticides do not use personal protective gear, such as safety masks, gloves, etc., as there is no awareness about the deleterious effects of pesticides.
  • Pesticides, applied over the plants, can directly enter the human body, and the concentration of nitrate in the blood can immobilize hemoglobin in the blood.
  • Organophosphates can also develop cancer if exposed for a longer period.
  • Dichlorodiphenyltrichloroethane (DDT) was a very common pesticide used in India, now banned internationally as it is found to bioaccumulate and cause severe harmful effects on human beings
  • owever, there is still illegal use of DDT in India.
  • It is proven that there is a significant correlation between agrochemical content in water and total birth defects.

Other Terms related to Green Revolution:

• Yield gap
  • The difference between the potential or maximum achievable yield of a crop and the actual realised yield for a given area is called the yield gap.
  • During the Green Revolution, one of the main areas of focus was the increase productivity from existing farmlands using HYVs in order to tackle the threat of famine.
• Cytogenetics
  • Cytogenetics is the study of chromosomes (DNA-carrying structures) and how they related to hereditary characteristics and traits.
  • Identifying traits such as resistance to diseases, drought, and pests in crops are applications of cytogenetics.
• Hexaploid wheat
  • Scientifically known as Triticum aestivum, hexaploid wheat contains six sets of chromosomes and is among the most widely cultivated cereal crops across the world.
  • It is also called “bread wheat”.
  • Dr. Swaminathan is associated with research on the cytogenetics of hexaploid wheat.
• Carbon fixation
  • Carbon fixation is the process by which crops capture carbon dioxide from the atmosphere and convert it into organic compounds like sugars and starches, mostly through photosynthesis.
  • Grass species either use C3 or C4 classes of photosynthetic pathway for carbon fixation.
    • The C3 pathway, also called the Calvin cycle, is slower in comparison to C4 – also called the Hatch and Slack pathway.
    • C3 cycle of fixation occurs when the tiny pores of surface of leaves (in the mesophyll cells) are open
    • While C4 occurs in both mesophyll cells and bundle sheath cells (that surround the veins of the plant), making photosynthesis more efficient.

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Topic 5: Jewar Airport gets ‘DXN’ code

Why in news: The upcoming Noida International Airport (NIA) in Jewar was awarded its own unique international three-letter code, ‘DXN’, by the International Air Transport Association (IATA).

What are airport codes?

• Airport codes are unique identifiers assigned to each airport.
• While most people are familiar only with the codes assigned by IATA, each airport actually has two unique codes:
  • The other assigned by International Civil Aviation Organization (ICAO), an arm of the United Nations.
• Both are used to accurately identify airports, but in different contexts.
  • The three-digit IATA codes are used for passenger facing operations — on tickets, boarding passes, signages, etc.
  • The four-digit codes assigned by the ICAO are used by industry professionals such as pilots, air traffic controllers, planners, etc.
• Airport coding first began in the 1930s, in the very early days of commercial aviation.

How does IATA assign airport codes?

• How the airport wishes to identify itself.
  • Lots of lobbying goes on behind the scenes by an airport authority to receive a code that is meaningful in some way.
  • City names, airport names, and location names are some common bases for codes.
• The availability of said code.
  • The codes are meaningful only because they are unique.
  • This means that no two airports can have the same IATA codes.
  • This is one of the reasons why the Ranchi airport is not RAN (taken by Ravenna, Italy).
• Certain common conventions, which depend on the country.
  • The other reason why the Ranchi airport is IXR is due to a convention followed in India where military airports extended for civilian traffic are assigned codes beginning with ‘IX’.
    • For instance, Agartala’s airport is IXA, Chandigarh’s airport is IXC, and Leh airport is IXL.
  • The assignment of these codes is governed by IATA Resolution 763 and are published twice each year in the IATA Airline Coding Directory.

About IATA:The International Air Transport Association (IATA) is a trade association of the world’s airlines founded in 1945.IATA has been described as a cartel since, in addition to setting technical standards for airlines, IATA also organized tariff conferences that served as a forum for price fixing.It consists of 300 airlines, representing 117 countriesThe IATA’s member airlines account for carrying approximately 83% of total available seat miles air traffic.IATA supports airline activity and helps formulate industry policy and standards.It is headquartered in Montreal, Canada.It is the successor to the International Air Traffic Association, which was formed in 1919 at The Hague, Netherlands.

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Topic 6: Sycamore Gap

Why in news: A 300-year-old tree in England that was famous for its beauty and unique location was cut down by a teenage boy, in what is being seen as a deliberate act of vandalism.

Key details:

• The sycamore tree was located in a dip between two hills, at a gap in the Hadrian Wall – an old stone structure that is close to the border between England and Scotland.
• The ‘gaps’ are essentially channels, which were naturally chipped away by vast amounts of meltwater flowing beneath the ice sheets that once covered the area, thousands of years ago.

Roots of Sycamore

• Sycamore trees can become extremely tall as they mature – reaching a height of up to 35 metres.
• They are commonly found in the UK and have leaves similar to that of a maple tree.
• A sycamore can live for as long as 400 years.
• Native to central, eastern and southern Europe, it is believed to have been introduced to the UK by the Romans or in the Tudor era around the 1500s.

UNESCO Heritage site

• The Hadrian Wall is part of a larger UNESCO World Heritage Site called the ‘Frontiers of the Roman Empire’ and is found in the UK and Germany.
• The Roman Empire, in its territorial extent, was one of the greatest empires history has known.
• Enclosing the Mediterranean world and surrounding areas, it was protected by a network of frontiers stretching from the Atlantic Coast in the west to the Black Sea in the east, from central Scotland in the north to the northern fringes of the Sahara Desert in the south.
• The larger frontier includes various sections, including the Hadrian Wall, which runs along 118 km.

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Topic 7: Digital world of cookies

Why in news: Platforms like Facebook and Google use cookies to track online behaviour, ensuring ads users encounter align with preferences.

What are cookies?

• Cookies (often known as internet cookies) are text files with small pieces of data — like a username and password — that are used to identify your computer as you use a network.
• Specific cookies are used to identify specific users and improve their web browsing experience.
• Data stored in a cookie is created by the server upon your connection.
• This data is labeled with an ID unique to your computer.
• When the cookie is exchanged between your computer and the network server, the server reads the ID and knows what information to specifically serve you.

How do cookies work?

• On websites like Amazon, cookies remember customer’s previous interactions; from products they have browsed to purchases they have made.
  • Armed with this knowledge, Amazon serves up tailored product recommendations and content, making the online shopping feel like a personalised boutique experience.
• Platforms like Facebook and Google use cookies to track online behaviour, ensuring the ads you encounter align with your preferences.

What are the types of cookies?

• Session cookies:
  • Session cookies are temporary cookies like post-it notes for websites.
  • They are stored in the computer’s memory only during the browsing session.
  • Once you close the browser, they vanish.
  • Session cookies help websites remember the actions as you navigate, like items in a shopping cart.
• Persistent cookies:
  • Persistent cookies are the digital equivalent of bookmarks.
  • They stay on the device after your browsing session ends.
  • Persistent cookies remember the login information, language preferences, and even the ads you have interacted with.
  • They are handy for a more personalised web experience.
• Secure cookies:
  • Secure cookies are only sent over encrypted connections, making them safer from prying eyes.
  • Secure cookies are often used for sensitive data like login credentials.
• Third-party cookies:
  • Third-party cookies are often used for tracking and advertising purposes, which can be both useful and, at times, intrusive.

Uses of cookies

• Firstly, they act as digital ID cards, aiding in user authentication by allowing websites to recognise and keep you logged in during the visit.
• Secondly, they foster a sense of personalisation, recalling your preferences such as language choice or website theme.
• Thirdly, they function as the digital equivalent of a persistent shopping cart, ensuring that items you have added online remain there when you return.
• Finally, cookies play a pivotal role in targeted advertising, as advertisers use them to display ads that align with a person’s interest and browsing history, making online shopping more enticing.

Challenges

• Privacy concerns:
  • Privacy concerns arise as cookies could track your online behaviour, which, while often harmless, can sometimes encroach upon your digital privacy.
• Security risks:
  • Security risks loom when cookies are inadequately secured, opening doors for cybercriminals to pilfer the personal information.
• User consent:
  • The era of user consent has dawned.
  • India’s newly enacted Digital Personal Data Protection Act 2023 now necessitates websites to acquire explicit consent from users prior to collecting or processing their personal data via cookies.
• Third party cookies:
  • Third-party cookies have sparked debates, prompting many web browsers to curb their usage to safeguard user privacy.
• Slow web experience:
  • The data deluge generated by the multitude of cookies can potentially clog the browser, leading to a sluggish web experience.

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Topic 8: Monoclonal antibodies

Why in news: Recently, India reached out to Australia to procure monoclonal antibody doses to combat the Nipah virus outbreak in Kerala.

What is a monoclonal antibody?

• Monoclonal antibodies are laboratory-made proteins that mimic the behaviour of antibodies produced by the immune system to protect against diseases and foreign substances.
• An antibodyattaches itself to an antigen.
  • Antigen is a foreign substance, usually a disease-causing molecule – and helps the immune system eliminate it from the body.
• Monoclonal antibodies are specifically designed to target certain antigens.
• Niels K. Jerne, Georges J.F. Köhler and César Milstein were awarded the medicine Nobel Prize in 1984 for their work on the the principle for production of monoclonal antibodies.

What is m102.4?

• m102.4 is a potent, fully human monoclonal antibody that neutralises Hendra and Nipah viruses, both outside and inside of living organisms.
  • Both Hendra and Nipah viruses are bat-borne Paramyxoviridae – a family of viruses that contain a single-strand RNA of negative-sense genome, similar to the ones that cause diseases like measles, influenza etc., and replicate within infected cells.
  • Hendra virus is on the World Health Organisation’s list of priority diseases requiring urgent attention for research and development of therapeutics — as is the Nipah virus.
• As of now, the drug is used on a ‘compassionate use’ basis — a treatment option that allows the use of an unauthorised medicine under strict conditions among people where no other alternative and/or satisfactory authorised treatment is known to be possible and where patients cannot enter clinical trials for various reasons.

How do monoclonal antibodies work?

• Monoclonal antibodies are specifically engineered and generated to target a disease.
• They are meant to attach themselves to the specific disease-causing antigen.
  • An antigen is most likely to be a protein.
  • For instance, most successful monoclonal antibodies during the pandemic were engineered to bind to the spike protein of the SARS-CoV-2 virus.
  • The binding prevented the protein from exercising its regular functions, including its ability to infect other cells.
• Glycoproteins are one of the major components of viruses that cause diseases in humans.
  • The m102.4 monoclonal antibody binds itself to the immunodominant receptor-binding glycoprotein of the Nipah virus, potentially neutralising it.