Science & Technology

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What is the Internet Archive?

Context: Internet Archive (IA) is embroiled in a major legal challenge as it faces off against traditional publishers accusing it of copyright violations. The free digital library is fighting the forced removal of around half a million books from its platform, which it argues functions like a library.

Internet Archive

It is an American nonprofit digital library founded in 1996 by Brewster Kahle.
It provides free access to collections of digitized materials including websites, software applications, music, audiovisual, and print materials.
The Archive also advocates for a free and open Internet.
Its mission is to provide ‘universal access to all knowledge’.
The Internet Archive allows the public to upload and download digital material to its data cluster, but the bulk of its data is collected automatically by its web crawlers, which work to preserve as much of the public web as possible.
Its web archive, the Wayback Machine, contains hundreds of billions of web captures.
The Archive provides specialized services relating to the information access needs of the print-disabled. Publicly accessible books were made available in a protected Digital Accessible Information System (DAISY) format.
DAISY is designed as a complete audio substitute for print material.

Case against Internet Archive:

Many traditional publishers have alleged that Internet Archive violated their copyrights and illegally made their books available to the public, by scanning physical copies and distributing the digital files.
Traditional publishers were against IA’s temporary ‘National Emergency Library’ (NEL) initiative that it launched during the COVID-19 pandemic. This was to allow more users to access the e-books in its collection while physical libraries were locked down.
- During the NEL, IA lifted the technical controls enforcing its one-to-one owned-to-loaned ratio and allowed up to ten thousand patrons at a time to borrow each e-book on the Website.
- In general, IA uses a system known as ‘controlled digital lending’ to limit the number of people who can access an ebook.
- It ended its emergency library system after being hit with the lawsuit.
- Internet Archive used the doctrine of fair use to defend itself in the case, but this did not hold up.
Hachette vs Internet Archive Case (2020):
- Traditional publishers Hachette, HarperCollins, Wiley, and Penguin Random House sued Internet Archive.
- In 2023, an order was issued in favour of the publishers.
- The order stated: IA’s Website includes millions of public domain e-books that users can download for free and read without restrictions. However, the Website also includes 3.6 million books protected by valid copyrights.

Why are books being removed?

As a result of the lawsuit, IA was forced to remove over half a million books from its database.
While IA identifies itself as a library, it has been compared to a shadow library or a piracy database by traditional publishers, who disagree with its ‘controlled digital lending’ approach.
Despite the removal, however, the Internet Archive is still home to a rich collection.
- It still contains 835 billion web pages, 44 million books and texts, 15 million audio recordings, 10.6 million videos, 4.8 million images, and 1 million software programs.
- Live concerts and television programs also make up part of this collection.

Wayback Machine:

The Wayback Machine is a digital archive of the World Wide Web founded by the Internet Archive in 1996 and launched to the public in 2001, it allows the user to go ‘back in time’ to see how websites looked in the past.
The Wayback Machine was created as a joint effort between Alexa Internet (owned by Amazon.com) and the Internet Archive.
Hundreds of billions of web sites and their associated data (images, source code, documents, etc.) are saved in a database.
There is a good chance of finding content such as old websites that no longer exist today, earlier versions of existing websites, deleted social media posts, archived versions of paywalled articles, and archived versions of content that is blocked or censored in some jurisdictions.
Wayback Machine is useful for personal research or to access information sources, but users should be cautious about relying on the data obtained through such sources, as the saved information can sometimes be outdated or inaccurate.
This has created more than 28 years of web history accessible through the Wayback Machine.
The platform claims users can explore over 866 billion saved web pages through its own search service.
‘Archive-It’ program identifies important web pages on the Internet Archive’s website.
- Archive-It: Created in early 2006, Archive-It is a web archiving subscription service that allows institutions and individuals to build and preserve collections of digital content and create digital archives.
- Archive-It allows the user to customize their capture or exclusion of web content they want to preserve for cultural heritage reasons.
- Through a web application, Archive-It partners can search, catalogue, manage, browse, and view their archived collections.
- Periodically, the data captured through Archive-It is indexed into the Internet Archive's general archive.
Not all web sites are available because many web site owners choose to exclude their sites.

Dengue

Context: With the onset of monsoon and flooding in Delhi-NCR, the city has reported more dengue cases in 2024 as compared to the previous five years. However, the figure can be attributed to better reporting, including from private laboratories.

Dengue disease:

Dengue is a viral illness caused by the dengue virus, which is an RNA virus from the Flavivirus genus.
Dengue is more common in tropical and subtropical regions.
Transmission:
- The virus is primarily transmitted to humans through the bites of infected Aedes aegypti mosquitoes.
- There is no evidence that dengue can be transmitted directly from person to person through casual contact, coughing/sneezing, or sexual contact.
- Rare cases of vertical transmission (from mother to child during pregnancy or childbirth) have been reported, but this is not a common mode of spread.
Symptoms: Fever, headache, nausea, muscle/joint pain, rash, and potentially hemorrhagic complications.
Treatment: There is no specific treatment or vaccines available for dengue, only supportive care. The primary public health focus for controlling dengue is on mosquito population control and preventing mosquito bites.

Zika Virus

Context: In response to reported cases of the Zika virus in parts of Maharashtra, the Union Health Ministry issued a nationwide advisory, emphasizing the importance of continuous vigilance. The advisory urges states to prioritize screening pregnant women for the Zika virus and to closely monitor the fetal development of those who test positive for the infection.

About Zika Virus:

Zika virus is a mosquito-borne virus first identified in Uganda in 1947 in a Rhesus macaque monkey followed by evidence of infection and disease in humans in other African countries in the 1950s.
Since 2007 outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific.
In outbreaks over the last decade Zika virus was found to be associated with increased incidence of Guillain-Barré syndrome.
- It is a serious autoimmune disorder that affects the peripheral nervous system.
- It initially presents weakness, tingling, and numbness in the limbs, which can progress to paralysis lasting 6-12 months or longer.
- The syndrome affects the nerves responsible for muscle movement, pain, temperature, and touch sensations.
- While more common in adults and males, it can occur in individuals of all ages.

Outbreaks of Zika virus disease were identified throughout most of the Americas and in other regions with established Aedes Aegypti mosquitoes.
Sexual transmission has been confirmed as an alternate route of Zika virus infection.
There is no specific treatment available for Zika virus infection or disease.
In 2016 WHO declared the Zika virus and microcephaly as Public Health Emergency of International Concern (PHEIC).

Structure of the Virus:

A team led by Dr. Richard Kuhn and Michael Rossmann examined the structure of a mature Zika virus particle at near-atomic resolution.
They used a technique called cryo-electron microscopy.

Cryogenic electron microscopy (cryo-EM) is a microscopy technique where samples are cooled to cryogenic temperatures.
For biological specimens, this involves preserving the structure by embedding it in vitreous ice.
Recent improvements in detector technology and software algorithms have enabled the determination of biomolecular structures at near-atomic resolution.
These advancements have made cryo-EM a popular alternative to X-ray crystallography and NMR spectroscopy for determining macromolecular structures without requiring crystallization.
In 2017, Jacques Dubochet, Joachim Frank, and Richard Henderson were awarded the Nobel Prize in Chemistry for their work in developing cryo-electron microscopy for high-resolution biomolecular structure determination in solution.

The Zika virus, a single-stranded RNA virus from the Flaviviridae family.
- Flaviviridae is a family of enveloped positive-strand RNA viruses that primarily infect mammals and birds.
- These viruses are mainly transmitted through arthropod vectors, particularly ticks and mosquitoes.
The virus has two major lineages: Asian and African, which are geographically distinct.
- The African lineage primarily infects monkeys and apes, with humans as secondary hosts.
- The Asian lineage primarily affects humans.
The RNA of the Zika virus translates into a single polyprotein:
- Encoding three structural proteins, which are capsid (C), membrane (M), and envelope (E). The structural proteins form the viral particle.
- Along with seven non-structural proteins. Non-structural proteins assist in genome replication, packaging, and manipulating host processes to benefit the virus.

Complications:

Zika virus infection during pregnancy is a cause of microcephaly and other congenital malformations in the infant, including limb contractures, high muscle tone, eye abnormalities and hearing loss. These clinical features are collectively referred to as congenital Zika syndrome.
- Microcephaly is a birth defect in which babies are born with a smaller than usual head and underdeveloped brain
Congenital malformations occur following both symptomatic and asymptomatic infection.
Zika infection in pregnancy can also cause complications such as fetal loss, stillbirth and preterm birth.
Zika virus infection can also cause Guillain-Barré syndrome, neuropathy and myelitis, particularly in adults and older children.

Transmission

Zika virus is primarily transmitted by infected mosquitoes of the Aedes (Stegomyia) genus, mainly Aedes aegypti, in tropical and subtropical regions. Aedes mosquitoes usually bite during the day.
These mosquitoes also transmit dengue, chikungunya and urban yellow fever.
Zika virus is also transmitted from mother to fetus during pregnancy, as well as through sexual contact, transfusion of blood and blood products, and possibly through organ transplantation.

Activated Carbon

Context: Indian researchers have devised a method to produce activated carbon from coconut husks which are a major agricultural residue in Kerala, suitable for supercapacitor fabrication.

Activated Carbon Explained:

Activated carbon or activated charcoal is a form of carbon processed to have small, low-volume pores that increase its surface area for adsorption or chemical reactions.
It is produced from carbonaceous materials such as wood, coal, or coconut shells, primarily through a two-step process involving carbonisation and activation.
- Carbonisation is the process of converting raw carbonaceous materials into a charred material by heating them (temperatures between 400-700°C) in the absence of air in an inert atmosphere (often nitrogen) to prevent combustion. This process removes volatile components (such as tar, methane, and other gases) and leaves behind a solid char (carbon-rich material).
- Activation enhances the porous structure of the char, increasing its surface area and making it highly effective for adsorption. Here, the char is exposed to oxidising gases such as steam or carbon dioxide at high temperatures (600-1200°C), which creates a network of pores.

Properties:

High Surface Area allows for a high capacity of adsorption.
Porosity: Numerous micro and macropores enhance its ability to trap and hold molecules from gases and liquids. Hence, it can adsorb a wide variety of substances, including organic compounds, chlorine, and some heavy metals, due to its high porosity and surface area.

Note:

Adsorption is a surface phenomenon where molecules, atoms, or ions from a gas, liquid, or dissolved solid adhere to the surface of a solid or liquid material. This process is different from absorption.
In absorption, the absorbate (the substance being absorbed) penetrates into the interior of the absorbent material.

Potential Uses:

Water Purification: Activated carbon is widely used in water treatment plants to remove organic compounds, chlorine, and other contaminants from drinking water.
Air Purification: It is used in air filters to capture volatile organic compounds (VOCs), odours, and pollutants in both industrial and residential settings.
Chemical Purification: Activated carbon is used to purify chemicals and solvents in the pharmaceutical and chemical industries.
Food and Beverage Industry: It is used for decolourisation and purification in the production of food and beverages, such as sugar refining and wine purification.
Medical Uses: Activated carbon is used in medical applications for treating poisonings and overdoses by adsorbing toxins in the gastrointestinal tract.
Gold Recovery: In the mining industry, activated carbon is used to extract gold from cyanide leach solutions.
Energy storage: Can be used to manufacture sustainable and efficient green solutions for energy storage like supercapacitors.

Capacitors:

A capacitor is an electronic device that stores electrical energy by accumulating electric charges on two closely placed conductive plates (electrodes) that are insulated from each other.
Supercapacitors with significantly higher capacitance and energy storage capacity than conventional capacitors are vital in the quest for sustainable energy storage solutions. But, the search for an ideal supercapacitor electrode material has been a challenge.
- Ideal supercapacitor should have:
  - High Surface Area: To maximise the amount of charge stored.
  - Good Electrical Conductivity: To ensure efficient charge transfer.
  - Chemical Stability: To maintain performance over many charge and discharge cycles.
  - Mechanical Stability: To withstand physical stress during operation.
  - Cost-Effectiveness: To be commercially viable for large-scale production.
  - Environmental Friendliness: To minimise environmental impact.

Latest development:

The prototype supercapacitors made of the coconut husk-derived activated carbon have been found to be four-times more efficient than the existing supercapacitors.
Further, the supercapacitors are sustainable and efficient green solutions for energy storage owing to the availability, low cost, and eco-friendly nature of coconut biowaste or biomass.

"ABHYAS" - High Speed Expendable Aerial Target

Context: Defence Research and Development Organisation (DRDO) under Ministry of Defence has successfully completed the developmental trials of High-Speed Expendable Aerial Target (HEAT) 'ABHYAS' with improved booster configuration from the Integrated Test Range, Chandipur, Odisha. 10 developmental trials for the ABHYAS have been successfully conducted which demonstrates the reliability of the system.

About ABHYAS

ABHYAS aims to provide a realistic threat scenario for weapon systems practice.
This indigenous system is designed for autonomous flying with the help of an auto pilot, a laptop-based Ground Control System for aircraft integration, pre-flight checks, and autonomous flight. It also has a feature to record data during flight for post-flight analysis.
ABHYAS has been designed by DRDO's Aeronautical Development Establishment, Bengaluru and developed through production agencies - Hindustan Aeronautics Limited (HAL) and Larsen & Toubro.

Potassium Cyanide

How does potassium cyanide cause sudden death?

Potassium cyanide when consumed causes death by gradually arresting the supply of oxygen to our body’s cells by forming complexes with haemoglobin and cytochrome (a protein which helps in the respiration of cells), depriving them of their capacity to transport or exchange oxygen.
Normally, oxygen is carried to different parts of the body from the lungs by the blood using haemoglobin, which is the iron-containing, oxygen-carrying molecule of the red blood cells.
Haemoglobin is made up of a globular protein and four heme groups. The iron (in ferrous state) present in these heme complexes can bond to either an oxygen molecule or a water molecule or exchange one for the other without much difficulty. It is because of this ability that haemoglobin is able to pick up oxygen from the lungs, carry it to the cells, and bring water in return.
Cells respire oxygen with the help of myoglobin (haemoglobin-like proteins present in the cells) and cytochrome, which carries electrons.
Specific forms of cytochrome and haemoglobin also cause sudden death when poisoned by cyanide.
- When potassium cyanide is consumed, it splits into a potassium ion and a cyanide ion.
- The cyanide ion has a greater affinity for the ferrous ion.
- As a result it occupies the site meant for oxygen in haemoglobin. This process is irreversible and prevents the transfer of oxygen.

One form of cytochrome, designated cytochrome-a, also binds with the cyanide ion and stabilises the iron to such an extent that it does not take part in the electron transfer to the cell. This prevents oxygen intake by the cell.
The symptoms of cyanide poisoning are giddiness, headache, and bluish tinge of the skin. If not treated immediately, unconsciousness and death will follow.

Potassium Cyanide:

It is a compound with the formula KCN.
It is characterized as a white crystalline solid.
Potassium cyanide is highly soluble in water.
It is a reducing agent and reacts with acids of all kinds to generate poisonous hydrogen cyanide gas.
- A reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an electron recipient (called the oxidizing agent or electron acceptor).

KCN is produced by treating hydrogen cyanide with an aqueous solution of potassium hydroxide, followed by evaporation of the solution in a vacuum: HCN + KOH → KCN + H2O.
Potassium cyanide is highly toxic, and a dose of 200 to 300 milligrams will kill nearly any human.

Applications:

Most KCN is used in gold mining, organic synthesis, and electroplating.
KCN is widely used in organic synthesis for the preparation of nitriles and carboxylic acids.
It also finds use for the synthesis of hydantoins, which can be useful synthetic intermediate.
Within the chemicals industry, potassium cyanide is most often used to help prepare chemicals for use in sectors such as manufacturing, pharmaceutical, and plastics. It is a powerful reagent for which the applications are growing alongside the demand for industrially manufactured products.
KCN is used as a photographic fixer in the wet plate collodion process.
- The KCN dissolves silver where it has not been made insoluble by the developer.
- This reveals and stabilizes the image, making it no longer sensitive to light.
- Modern wet plate photographers may prefer less toxic fixers, often opting for sodium thiosulfate, but KCN is still used.
- In the 19th century, cyanogen soap, a preparation containing potassium cyanide, was used by photographers to remove silver stains from their hands.

Why is the success of China’s sample return lunar mission significant?

Context: China’s Chang’e-6 became the first spacecraft to bring back samples from the far side of the Moon to the Earth.

Timeline of Chang’e-6:

The Chang'e-6 probe was successfully launched from China on a Long March-5 rocket on May 3, 2024.
The lander descended on the Moon’s surface on June 1 and spent two days collecting rocks and soil from one of the oldest and largest of lunar craters — the 2,500 km-wide South Pole-Aitken (SPA) basin — using a robotic arm and drill.
- The lander then launched an ascent module that transferred the samples to the Chang’e-6 orbiter that was orbiting the Moon.
On June 21, the orbiter released a service module that brought back the samples to Earth. The Chang'e-6 probe returned to Earth on June 25, bringing back the first-ever samples from the far side of the moon.
Aim: The sample return mission aims to collect and return samples from the far side of the Moon to Earth for analysis. The sample can be rocks or soil or even some molecules.

Is this the first time a spacecraft has brought lunar samples to Earth?

Back in July 1969, the US Apollo 11 mission brought 22 kg of lunar surface material, including 50 rocks, to Earth.
In September 1970, the Soviet Luna 16 mission — the first robotic sample return mission — too, brought pieces of the Moon to Earth.
In December 2020, China’s Chang’e-5 brought back 2 kg of lunar soil.

All these samples came from the near side of the Moon.

Note:
- China is the only country to achieve a soft-landing on the far side of the Moon. In 2019, its Chang’e-4 mission landed on the far side and explored the Moon’s Von Karman crater with the help of a rover.
- Difficult terrain, giant craters, and the difficulty in communicating with ground control made it technically challenging to land a spacecraft on the far side that never faces the Earth.

Facts about the Moon:

The Moon is tidally locked to Earth, meaning that the same side of the Moon always faces Earth. This side is known as the near side, while the opposite side is called the far side or the "dark" side (although it does receive sunlight).
- The Moon takes roughly the same amount of time to complete one full orbit around the Earth as the Moon takes to complete one full rotation on its axis.
- As a result, one side of the Moon always faces the Earth, while the other side (far side) faces away from Earth. Thus, we can see only one side of the Moon.

Near side and Far side of the Moon have strikingly different appearances:

Near side:

The near side is characterised by large, dark basaltic plains called maria (dark spots), which are believed to have formed from ancient volcanic eruptions. These maria cover about 31% of the near side and are less common on the far side.
The near side also has fewer impact craters compared to the far side.

Far side:

The far side is more heavily cratered and lacks the extensive maria (dark spots) found on the near side.
The far side has a thicker crust and is more mountainous, with the highest elevations on the Moon. It has a thicker crust by almost 20 km.
One of the most prominent features on the far side is the South Pole-Aitken basin, which is the largest known impact crater in the Solar System.

Why are sample return missions significant?

Lunar missions are exploring ways to stay for long on the Moon and to use its resources in situ.

Detailed analysis of samples:
- In situ robotic explorations — in which landers, orbiters, and rovers carry out experiments in space or on heavenly bodies — can carry only miniature instruments that are not very sophisticated or accurate and have limitations. For example, they cannot determine the origin or age of a rock.
- If the samples can be brought to Earth, the scientists can examine them using extremely sensitive laboratory instruments. They can study the chemical, isotopic, mineralogical, structural, and physical properties of extraterrestrial samples from the macroscopic level down to the atomic scale.
- The returned samples can be preserved for decades and can be examined by future generations using ever more advanced technology.
Insights into Moon:
- Samples collected from the SPA basin can reveal the timeframe for lunar cratering. The collision that created the basin may have excavated enough material from the Moon’s lower crust and upper mantle, which could give insights into the Moon’s history and its origin.
- An examination of the Chang’e-6 samples could throw up some answers on why the lunar far side is geologically different from the near side.
Lunar Resources:
- Far side might hold resources like water ice trapped in permanently shadowed craters. Ice can be harvested for water, oxygen and hydrogen — and the latter two can be used in a rocket propellant. These resources could be vital for future lunar settlements or exploration efforts.
- The samples can suggest ways to use lunar resources for future lunar and space exploration. For instance, lunar soil could be used to produce bricks to build future lunar research bases through 3D printing.
- Moon can be used in the near future as a launch pad to travel deeper into space and to other extraterrestrial bodies.

Note:

India’s Chandrayaan-4 mission, which is currently under development by the Indian Space Research Organisation (ISRO), will also be a sample return mission.
Chandrayaan-3 landed about 600 km from the South Pole of the Moon in August 2023.

Methanol Poisoning

Context: At least 47 people have died and nearly 100 others are battling for their lives after consuming a methanol-spiked alcohol in Tamil Nadu.

What is the alcohol in liquor?

Liquor is differentiated by its alcohol content – from the 5% or so of beer to the 12% or so of wine to the 40% or so of distilled spirits (all by volume).
In the beverages consumed for recreational purposes, the alcohol used is ethanol.

Ethanol:

Ethanol: Ethanol (C2H5OH), in low doses, is a psychoactive drug that reduces the level of neurotransmission in the body leading to its typical intoxicating effects.
- The World Health Organisation has found that no level of alcohol consumption is safe for our health.
- Long-term use leads to dependence, heightens the risk of some cancers and heart disease, and may eventually cause death.
Inside the body, it is metabolised in the liver and the stomach by alcohol dehydrogenase (ADH) enzymes to acetaldehyde. Then, aldehyde dehydrogenase (ALDH) enzymes transform the acetaldehyde into acetate. The adverse effects of alcohol consumption, from the hangover to cancer, are due to acetaldehyde.

What is spurious liquor?

Spurious liquor is characterised by the liquid mixture containing methanol as well. Such liquors are typically homemade to which methanol is added to strengthen the intoxicating effects (in colloquial parlance, its kick) and/or to increase its bulk volume.
The Food Safety and Standards (Alcoholic Beverages) Regulations 2018 stipulate the maximum permissible quantity of methanol in different liquors. These values span a wide range, including “absent” in coconut fenny, 50 grams per 100 litres of country liquor, and 300 grams per 100 litres of pot-distilled spirits.

Methanol:

The methanol molecule (CH3OH) consists of one carbon atom bonded with three hydrogen atoms and one hydroxyl group.
Methanol is a toxic industrial chemical mentioned in the Schedule I of the Manufacture, Storage and Import of Hazardous Chemical Rules 1989.
The most common way to produce methanol is to combine carbon monoxide and hydrogen in the presence of copper and zinc oxides as catalysts at 50-100 atm of pressure and 250° C.

Applications of Methanol:

Methanol has several industrial applications:

Production of chemicals: Methanol is a basic building block for the production of many chemicals, including formaldehyde, acetic acid, MTBE (methyl tert-butyl ether) and other aromatic hydrocarbons.
Fuel: Methanol is a clean-burning fuel that can be blended with petrol or used in pure form in specially designed engines.
Solvent: Methanol is a good solvent and is used in various industrial and commercial applications, such as in the production of paints, coatings, inks, and cleaning agents.
Antifreeze: Methanol is used as an antifreeze because it has a low freezing point. It is often mixed with water to create a coolant for engines.

How does spurious liquor kill?

The deadliness of spurious liquor arises from methanol. The human body contains infinitesimal quantities of methanol (4.5 ppm in the breath of healthy individuals) as a result of eating some fruits. But even for an adult, more than 0.1 ml of pure methanol per kilogram of body-weight can be devastating.
Once ingested, methanol is metabolised in the liver by ADH enzymes to form formaldehyde (H-CHO). Then, ALDH enzymes convert formaldehyde to formic acid (HCOOH). The accumulation of formic acid over time leads to a baneful condition called metabolic acidosis. Acidosis can lead to acidemia: when the blood’s pH drops below its normal value of 7.35, becoming increasingly acidic.
Formic acid also interferes with an enzyme called cytochrome oxidase, which in turn disrupts cells’ ability to use oxygen and leads to the build-up of lactic acid, contributing to acidosis.
Further, consuming methanol also leads to “methanol-induced optic neuropathy”- a serious condition that may result in long-term or irreversible visual impairment or even blindness due to damage and loss of function of the optic nerve and retina.
Eventually, Methanol-poisoning can cause swelling in the brain, haemorrhage, and death.

Immediate ways to treat Methanol poisoning:

One is to administer ethanol (of a pharmaceutical grade, by healthcare workers). This may sound counterintuitive but ethanol competes very well with methanol for the ADH enzymes, which metabolise ethanol around 10x faster. As a result, the methanol is kept from being metabolised to formaldehyde.
Second option is to administer an antidote called fomepizole, which has a similar mechanism: it slows the action of the ADH enzymes, causing the body to produce formaldehyde at a rate that the body can quickly excrete, preventing the deadlier effects from kicking in.
Other options include:
- Undertaking a dialysis to remove methanol and formic acid salts from the blood, and mitigating damage to the kidneys and the retina.
- Administering folinic acid which encourages the formic acid to break up into carbon dioxide and water.

KAVACH System

Context: The recent railway accident in Darjeeling, West Bengal has highlighted the need for installation of the KAVACH system to prevent such tragedies.

What is KAVACH?

KAVACH is an indigenously developed Automatic Train Protection System (ATPS) by the Research Design and Standards Organisation in collaboration with Indian industry.
It is a state-of-the-art electronic system with Safety Integrity Level-4 standards with the probability of an error being one in 10,000 years.

Features of KAVACH:

It gives information to the locopilots on the permissible speeds to be maintained and prevents the collision between two locomotives equipped with functional KAVACH systems.
It activates the train’s braking system automatically if the driver fails to control the train as per speed restrictions.
- If a red signal is jumped (which marks danger) and two trains come face to face on the same line, the technology automatically takes over and applies sudden brakes.
- Additionally, the hooter activates by itself when approaching a level crossing which serves as a big boon to loco-pilots during fog conditions when visibility is low.
The system also relays SoS messages during emergency situations. An added feature is the centralised live monitoring of train movements through the Network Monitor System.

How does KAVACH work on Railway Systems?

Traffic Collision Avoidance System (TCAS) helps in two-way communication between the station master and loco-pilot to convey any emergency message, using GPS and RFID technology.
- GPS Integration:
  - KAVACH relies on GPS to continuously track the location and speed of trains. The onboard unit in each train receives GPS signals, which are used to determine the train's precise position, direction, and speed.
  - This real-time location data is then communicated to the central control system and other trackside equipment.
- RFID Implementation:
  - A set of electronic devices and Radio Frequency Identification (RFID) devices are installed in locomotives, in the signalling system as well as the tracks.
  - As the train passes over these RFID tags, the onboard RFID reader in the train detects the tag and communicates the information to the onboard unit.
  - They connect using ultra-high radio frequencies to control the brakes of trains and also alert drivers, all based on the logic programmed into them.
  - Hence, it allows KAVACH to accurately identify the train's location and trigger the appropriate safety actions, such as automatic braking, if necessary.

Integrated Functionality:

The combination of GPS and RFID technologies in KAVACH provides a comprehensive system for train tracking, collision avoidance, and overall railway safety.
The GPS data gives a broad, continuous overview of the train's position and movement, while the RFID tags offer precise location references at specific points along the track.

Using firewall to block Internet access

Context: Pakistani media outlets reported that the country is planning to implement a Chinese-style firewall to block users from accessing social media platforms. Even those using Virtual Private Networks (VPN) to access the Internet are likely to be hit by this firewall.

Digital firewall

A digital firewall is a network security system that monitors and controls incoming and outgoing network traffic based on a set of predefined security rules.
- The security tools can stop online traffic from reaching certain sites. They can prevent malicious actors from targeting individual users’ computer systems or home networks, and even thwart cyber threats on specific websites.
- Large firewalls (like the Great Firewall of China) can be used to prevent people from accessing large sections of the Internet i.e, websites, social media sites or information gathering platforms.
Firewalls can be implemented as hardware devices, software running on a computer, or as a cloud-based service.

How does a digital firewall work?

Packet Inspection: The firewall examines each data packet (a unit of data transmitted over a network) that passes through it. It looks at the header information of the packet, which includes the source and destination IP addresses, port numbers, and protocol type (e.g., TCP, UDP).
Access Control Lists (ACLs): The firewall compares the packet information against a set of predefined rules known as an Access Control List. These rules specify which traffic is allowed to pass through the firewall and which traffic should be blocked.
Filtering Decisions: Based on the ACL rules, the firewall makes a decision on whether to allow the packet to pass through or to block it.

Why is it used?

Firewall presents a viable alternative to authoritarian nation states who wish to replace a larger free Internet with a controlled intranet.
- When used by nation-states, a firewall restricts activists, journalists, dissidents, and regime critics from obtaining information critical of the government.
- Internet shutdowns and social media blocks also prevent governments or military authorities from being held accountable during periods of civil unrest and violence.
However, setting up and maintaining a firewall is expensive. The firewalls require constant monitoring to thwart bad actors and fix security vulnerabilities.

Right to Internet in India:

In the Anuradha Bhasin v/s Union of India 2020, the Supreme Court ruled that the right to freedom of speech and expression and the freedom to practise any profession or carry on any occupation, trade or business over the internet are protected under Article 19 (1) (a) and Article 19 (1) (g) of the Indian Constitution, respectively.
This essentially means that the court recognised internet access as a fundamental right, integral to a democratic society for its proper functioning.

Progress towards long-awaited HIV vaccine

Context: Researchers at the Scripps Research Institute and the Massachusetts Institute of Technology have outlined two nanoparticle-based vaccine candidates: N332-GT5 and eOD-GT8. These novel vaccines could help the body make two classes of broadly neutralising antibodies to attack HIV.

HIV and AIDS:

HIV (human immunodeficiency virus) is an RNA virus. It belongs to the retrovirus family, which is characterised by the presence of RNA as its genetic material.
HIV damages the immune system and attacks cells that help the body fight infection, making a person more vulnerable to other infections and diseases. If left untreated, HIV can lead to the disease AIDS (acquired immunodeficiency syndrome).
HIV primarily targets CD4 cells, which are a type of white blood cell essential for the proper functioning of the immune system.
Transmission:
- Contact with certain bodily fluids (infected blood, semen, or vaginal fluids) of a person with HIV, most commonly during unprotected sex or sharing injection drug equipment.
- Can also transmit from an HIV-positive mother to her child during childbirth, breastfeeding, or pregnancy.
- Mosquitoes or any other insect vector cannot transmit HIV, unlike malaria (HIV can only survive in human blood).
Treatment: Human body cannot get rid of HIV and no effective HIV cure exists. Medications like antiretroviral therapy or ART can control the infection and prevent disease progression.

No vaccine for AIDS:

AIDS still has no vaccine or cure. The reason is that the replication of the human immunodeficiency virus (HIV) is an incredibly error-prone process that results in multiple variants of the virus circulating.
- HIV has more variants circulating in a single patient at any given point of time than influenza cumulatively generates in one year in all influenza patients around the world combined. And influenza is the second-best virus in terms of genetic variation.

Starring role for B-cells:

When the immune system encounters a virus, one of its responses is to produce antibodies highly specific to proteins on the virions’ surface.
The immune system does this with the help of a pool of specialised cells (B-cells) that produce antibodies. Each B-cell produces an antibody unique to one protein fragment.
These antibodies then bind to corresponding proteins on the viral surface, rendering them incapable of further infection.
- The body then retains some of these specific antibody-producing cells in case of a future infection.
A vaccine aims to generate these antibodies prior to viral infection so that whenever a virus enters the body, the antibodies can neutralise the virus and prevent it from initiating an infection.

Broadly neutralising antibodies (bNAb):

However, when multiple variants of the same virus exist, generating antibodies against all the different variants simultaneously becomes very difficult.
- Incase of HIV, the sheer volume of different variants of the virus circulating overwhelms the immune system’s ability to generate new antibodies.
- Additionally, by the time the immune system makes antibodies against a few strains, the virus will have produced hundreds more variants.
Broadly neutralising antibodies (bNAb) are a kind of antibody that can neutralise a large number of circulating viral strains. These antibodies (bNAb) worked by targeting areas of the viral proteins that the virus could not afford to change, since doing so would make it lose infectivity. Scientists have discovered many bNAbs, and they are classified into different groups based on the region of HIV they target.

The challenge and the way forward:

A body usually takes years to make bNAbs, and by then the virus has already evolved to escape them. It takes years because the parental B-cells that make the bNAbs are incredibly rare.
The immune system can produce these bNAbs in large numbers in response to a vaccine by germline targeting. It has three steps.
- In the first step, those B-cells that can mature into cells that can produce bNAb are identified and engaged to increase their population.
- In the second-step, a booster dose will guide these cells into generating stronger bNAbs against HIV.
- The final step is to refine these bNAbs such that they can neutralise a wide range of HIV strains.

Progress:

Researchers have developed two promising nanoparticle-based vaccine candidates: N332-GT5 and eOD-GT8. Using these novel vaccines, it may be possible to engage B-cells to make two different classes of bNAbs.
The antibodies generated in response to the vaccines bind to the HIV proteins in a manner similar to that of established bNAbs. The candidate vaccines are currently being evaluated in a phase-1 clinical trial to assess their performance in humans.

Optical Atomic Clock

Context: Researchers have developed an miniaturised Optical Atomic Clock which can be placed in a ship. This Optical Atomic Clock is considered to be more accurate as compared to Caesium based Atomic clocks.

About Atomic Clock

Optical atomic clocks are a cutting-edge technology in precise timekeeping, offering superior accuracy compared to traditional atomic clocks.
They utilize optical frequencies (visible, ultraviolet, and infrared light) for time measurement, leading to higher precision.

Principle of Operation

Atomic Transitions: Operate on the same principle as traditional atomic clocks, but with transitions stimulated by lasers.
- Resonance Frequency: In the optical range, leading to more precise and stable measurements.
Lasers: Coherent light sources used to stimulate atomic transitions with high precision.
- Coherent Light: Emitted light waves have the same frequency and stable wavelength relationships.
Higher Frequency: Optical clocks operate at much higher frequencies than microwave-based atomic clocks, enabling finer time resolution.

Common Atoms Used

Strontium (Sr): Preferred for its stable optical transitions and narrow linewidths.
Ytterbium (Yb): Also used for its similar properties to strontium.
Iodine (I2): Used in the new portable optical atomic clock for its robustness and relatively high accuracy.
Caesium (Cs-133): Traditional atomic clocks often use caesium for its stability and natural occurrence.

Advantages of Optical Atomic Clocks

Accuracy: Optical atomic clocks can lose or gain only one second over 300 billion years, compared to traditional atomic clocks' 1.4 million years.
Stability: Higher operating frequencies and narrower linewidths lead to exceptional long-term stability.
Precision: Ability to measure smaller time increments more accurately.

Development and Application of a New Portable Optical Atomic Clock

New Portable Design: Recent study published in Nature introduces a portable optical atomic clock that uses molecular iodine as the frequency standard.
Miniaturization: The clock's components were miniaturized to fit within a standardized rack (35 liters, 26 kg, 85 W power consumption).
- Spectrometer: Volume reduced to 2.5 liters.
- Laser System: Constructed using optical fibers, reducing volume to 1 liter.
- Frequency Comb: Occupies 0.5 liters.
Autonomous Operation: Equipped with a software control system for autonomous initialization and monitoring.
Testing and Performance: Conducted initial tests at the U.S. National Institute of Standards and Technology (NIST), operating autonomously for 34 days.
- Accuracy: Outperformed NIST’s hydrogen maser ST05 in short-term accuracy and had 10x lower long-term drift compared to rubidium atomic clocks.
Field Tests: Deployed on a ship at Pearl Harbor, Hawaii, maintaining stability despite environmental fluctuations (motion, temperature, humidity).

Applications

Maritime and Navigation: Enhances navigation and communication at sea.
Scientific Research: Facilitates precise monitoring of underwater seismic and volcanic activity.
Space Exploration: Aids in conducting experiments on the theories of relativity and can potentially reduce satellite-based navigation costs.

Challenges and Future Prospects

Portability: Continued efforts to make optical atomic clocks more portable without compromising accuracy.
Cost: Reducing the cost of optical atomic clocks to make them more accessible for widespread use.
Integration: Integrating optical atomic clocks into existing infrastructure for navigation, communication, and scientific applications.

Conclusion

Optical atomic clocks represent a significant advancement in timekeeping technology, offering unparalleled accuracy and stability.
The development of portable optical atomic clocks opens up new possibilities for practical applications in navigation, scientific research, and space exploration.
Ongoing research and development aim to further enhance their portability, reduce costs, and expand their applications, making them a vital tool for the future.