UPSC current affairs, 19-25 Oct, 2026

Why in news

• Oil marketing companies have excluded ethanol made from sugarcane juice, sugar syrup and B-heavy molasses from their procurement tender for the 2026–27 ethanol supply year.
• The change seeks to protect domestic sugar availability following poor rainfall in important producing States.

What changes?

• The tender seeks approximately 11 billion litres of ethanol for the supply year beginning in November 2026.
• Ethanol from maize, broken rice, surplus Food Corporation of India rice and C-heavy molasses remains eligible.
• The procurement price for maize-based ethanol falls from ₹71.86 to ₹68.86 per litre, following a reduction in its incentive.

Understanding the feedstocks

Significance and concerns

• E20 means petrol containing 20% ethanol by volume.
• Blending replaces part of petrol consumption and can reduce dependence on imported crude oil.
• Diverting agricultural produce towards fuel can compete with food, animal feed, land and water requirements.
• Greater reliance on grains makes their availability, procurement prices and distillery capacity increasingly important.
• The restriction concerns the specified procurement cycle; it should not be described as a permanent prohibition on all sugar-industry ethanol.

Why in news

• Researchers at the National Institute of Immunology, New Delhi, found that the protein RelB can produce contrasting effects on intestinal immunity, depending on where it acts.

Essential concepts

• Inflammatory bowel disease (IBD) includes Crohn’s disease and ulcerative colitis, which involve persistent intestinal inflammation.
• Dendritic cells detect threats and coordinate immune responses.
• Interleukin-23 (IL-23) supports defence against microbes, but excessive activity can contribute to chronic inflammation.
• Regulatory T-cells restrain excessive immune responses and protect the body’s tissues.

Why RelB has contrasting effects

Significance

• Understanding these contrasting roles could help develop treatments that reduce harmful inflammation while preserving protective immunity.

Why in news

• Russia’s Cosmos-2612 reportedly changed its orbit repeatedly to approach ICEYE-X36, a commercial radar-imaging satellite registered in the United States.
• The manoeuvres raised concerns about interference and the security of commercial space infrastructure.

What are proximity operations?

• Rendezvous and proximity operations (RPO) involve bringing one spacecraft close to another.
• They can support inspection, maintenance, refuelling and repair.
• An unexplained approach without the other operator’s agreement can create uncertainty about intentions.

Important facts

• The satellites operate approximately 550 kilometres above Earth.
• An assessment placed them roughly 1–2 kilometres apart during the reported approach.
• ICEYE-X36 was launched in March 2024 and weighs approximately 90 kilograms.
• Its synthetic aperture radar uses transmitted radio signals and spacecraft movement to produce detailed images, including through clouds and darkness.
• ICEYE supplies imagery to Ukraine, but the specific military use of ICEYE-X36 had not been publicly established.

Risks and legal questions

• Close approaches can create collision risks, force fuel-consuming avoidance manoeuvres or disrupt imaging.
• Jamming or physical interference are possible concerns; the reported manoeuvres do not establish that either occurred.
• Article IX of the Outer Space Treaty, 1967, requires due regard for other States’ activities and provides for consultations over potentially harmful interference.
• No universally agreed minimum separation distance applies to all satellites.
• Damage could raise questions of responsibility and liability, including under the Liability Convention, 1972.

Why in news

• An analysis of labour-survey data shows that increasing female participation has been uneven across northeastern States and Union Territories.

Understanding the indicators

• Labour-force participation rate (LFPR) measures the proportion of a population that is working or seeking or available for work.
• Female LFPR applies this measure to women.
• The worker-population ratio counts those actually employed.
• The unemployment rate measures unemployed people as a proportion of the labour force.

What the comparison shows

• Between 2019–20 and 2025, rural female participation increased from 33% to 45.9%.
• Urban female participation increased from 23.3% to 27.7%.
• Arunachal Pradesh showed strong improvement in both rural and urban participation.
• Several northeastern States improved, while Union Territories displayed more varied trends, including declines in some cases.

Why the starting point matters

• The level of participation and the pace of improvement answer different questions.
• A State starting with low participation may improve rapidly while remaining below another State.
• A State starting at a relatively high level may record slower improvement while retaining stronger participation.
• Comparisons should therefore examine both the initial level and subsequent change.

What higher participation does—and does not—show

• Rising participation does not automatically establish growth in secure, well-paid employment.
• Women may enter self-employment, casual work or unpaid work in household enterprises.
• Assessment must also consider earnings, working conditions, hours, social protection and unpaid care responsibilities.

Why in news

• Renewed attention to Pattanam has highlighted the need to revive sustained archaeological research, conservation and community participation.

Location and historical setting

• Pattanam lies near North Paravur in Kerala’s Ernakulam district, within the Periyar delta landscape.
• Archaeological evidence broadly dates from 300 BCE to 300 CE, with substantial material from 100 BCE to 300 CE.
• The settlement participated in networks connecting South Asia with West Asia, the Red Sea, Africa and the Mediterranean.

Important discoveries

• Excavations between 2006 and 2023 covered 67 trenches.
• They yielded approximately 1.3 lakh registered artefacts and 45 lakh pottery fragments.
• Finds include pottery, beads, coins, metals, wells, workshop remains and evidence of a harbour.
• A wooden canoe has been dated approximately between 100 BCE and 100 CE.
• Less than 1% of the archaeological mound, extending over more than 100 acres, has been excavated.

Connection with Muziris

• The discoveries place Pattanam within the maritime trading world associated with Muziris, also known as Muciri Pattinam.
• Identifying the entire ancient port definitively with present-day Pattanam remains an open archaeological question.
• Its significance extends beyond Roman trade: it reveals wider exchanges of people, goods, technologies and ideas.

Conservation concerns

• Modern habitation and infrastructure overlap the archaeological landscape.
• Conservation requires sustained research, protection of important plots and cooperation with residents.
• Heritage management should combine scientific investigation with education and local livelihoods.

Why in news

• A study examined children’s online experiences, while concerns about artificial intelligence have renewed debate over how digital tools affect learning and independent thinking.

What the study highlighted

• The study covered over 2,000 children aged 9–14 years in Delhi and approximately 500 parents.
• Around 97.6% of the children accessed the Internet from home, primarily through smartphones.
• Children reportedly spent approximately 4.5 hours daily online, using it for studying, gaming, watching videos and communicating.
• Nearly 47% reported communicating with unknown people during the previous six months.

Understanding the cognitive effects

• Cognitive offloading means transferring mental tasks to an external tool, such as using a calculator or asking artificial intelligence to summarise a passage.
• Such assistance can support learning. However, repeatedly obtaining ready-made answers can reduce opportunities to practise reasoning, recall and problem-solving.
• Neuroplasticity is the brain’s ability to change through experience. Activities repeatedly practised during childhood help shape attention, memory and emotional regulation.

Significance and concerns

• Digital tools can improve access to information, creativity and collaborative learning.
• Excessive or poorly supervised use can interfere with sleep, physical activity and sustained attention.
• Schools should preserve independent reading, discussion and problem-solving while teaching children to question digital outputs.
• The survey identifies reported experiences and associations; it does not establish that Internet use alone caused developmental problems.

Why in news

• India’s developing carbon market has prompted discussion about joining the Open Coalition on Compliance Carbon Markets (OCCCM).
• The coalition adopted its work plan at a meeting in Wuhan on 14 September 2026. India has not joined.

What is a compliance carbon market?

• It is a government-regulated system in which covered businesses must meet specified emissions requirements.
• Under India’s Carbon Credit Trading Scheme (CCTS), covered industrial units receive targets for emissions intensity, meaning greenhouse-gas emissions per unit of production.
• A unit performing better than its target can earn tradable certificates. A unit missing its target must obtain certificates to meet its obligation.
• This creates a financial incentive to reduce emissions where doing so is cheaper.

About the coalition

• The OCCCM is a voluntary international partnership supporting cooperation between government-regulated carbon-pricing systems.
• Its origins lie in a declaration at COP30 in November 2025. It was formally launched in Florence on 7 May 2026.
• Its members are Brazil, China, the European Union, Canada, France, Germany, New Zealand, Norway, Singapore, Türkiye and the United Kingdom.
• Observers include Monaco, Zimbabwe and organisations such as the United Nations Environment Programme and World Resources Institute. Observers are distinct from members.

Structure and functions

• Brazil chairs the coalition, while China and the European Union serve as co-chairs.
• High-Level and Executive Meetings guide its work. Working groups prepare technical recommendations, supported by a virtual secretariat.
• Cooperation covers carbon accounting, market design and measurement, reporting and verification, which establish whether emissions figures and reductions are reliable.

Why it matters for India

• Cooperation could improve India’s market rules, verification capacity and understanding of other countries’ systems.
• The Bureau of Energy Efficiency administers India’s scheme, the Grid Controller of India operates its registry, and the Central Electricity Regulatory Commission regulates trading.
• Reliable emissions accounting is also relevant to the European Union’s Carbon Border Adjustment Mechanism, which applies a carbon cost to specified imports.
• Coalition membership does not automatically link markets, recognise Indian credits abroad or exempt exports from border charges.
• Weak verification, double counting and unstable prices remain important risks.

Why in news

• The fifth edition of the India–Australia military exercise began on 19 October 2026.

Significance

• Interoperability means the ability of different armed forces to communicate, plan and operate effectively together.
• The exercise strengthens practical cooperation and mutual understanding between India and Australia in the Indo-Pacific.

Why in news

• A nationwide campaign will run from 21 October to 31 December 2026, covering approximately 2.70 lakh gram panchayats and urban local bodies.

Purpose and coverage

• The Department of Financial Services, Ministry of Finance, will coordinate the campaign through banks.
• Saturation means reaching all eligible people who remain outside the intended coverage of a service or scheme.

Significance

• Financial inclusion requires usable accounts, affordable insurance, access to credit and retirement protection.
• Updated records and nominations can help prevent interrupted services and difficulties in claiming funds.

Why in news

• The Food Safety and Standards Authority of India (FSSAI) has proposed maximum residue limits for two pesticides in tea through draft amendments published on 16 October 2026.

What is being proposed?

Understanding maximum residue limits

• Pesticide residues are traces remaining in food after pesticides have been used during cultivation.
• A maximum residue limit (MRL) is the highest legally permitted concentration of a specified pesticide residue in a particular food.
• It is a food-compliance standard, rather than a recommended pesticide application dose.
• Limits differ between pesticides and foods because their uses, residue behaviour and safety assessments differ.

Regulatory significance

• FSSAI is established under the Food Safety and Standards Act, 2006.
• Defined limits provide benchmarks for laboratory testing, inspections and enforcement.
• Exporters must also meet the standards applicable in destination markets.
• These remain proposed limits, subject to consultation and finalisation.

Why in news

• China announced export controls on tunnel-boring machines and certain other heavy construction equipment, effective from 18 November 2026.

What is being controlled?

• Tunnel-boring machines (TBMs) excavate underground tunnels used for metro systems, railways and other infrastructure.
• The restrictions also cover walking excavators and specialised machines that spray concrete to reinforce tunnels in mountainous terrain, including equipment used above 3,000 metres.
• These machines have dual-use applications, meaning they can support both civilian infrastructure and military construction.

How will the controls work?

• Exports to designated sensitive destinations and regions involved in disputes with China will require licences.
• Other destinations will face registration and certification requirements. Export controls therefore introduce official scrutiny and conditions rather than automatically prohibiting every shipment.

Why does this matter for India?

• India imports specialised tunnelling equipment for metro networks and strategically important infrastructure, including projects near its borders.
• Difficulties in obtaining Chinese export clearances have affected machinery supplies since 2024.
• Delayed deliveries can increase construction costs and postpone infrastructure projects.
• The development highlights the importance of diversifying suppliers, developing domestic manufacturing capabilities and maintaining access to specialised components and servicing.

Why in news

• Scientists have produced Doppler velocity images of the Sun’s corona using the Visible Emission Line Coronagraph (VELC) aboard Aditya-L1.

What do these terms mean?

• The corona is the Sun’s outer atmosphere, containing extremely hot plasma. Plasma is gas in which many atoms have lost electrons.
• A coronagraph blocks the Sun’s bright disc so that its much fainter surrounding atmosphere can be studied.
• The Doppler effect is a change in the observed wavelength caused by movement towards or away from an observer.
• Light shifts towards shorter wavelengths when material approaches and towards longer wavelengths when it moves away. These shifts help scientists calculate motion along the observer’s line of sight.

What is new?

• VELC, developed by the Indian Institute of Astrophysics, uses spectroscopy—the study of light separated into its wavelengths—to map plasma movement.
• These measurements help determine whether erupting material is moving towards or away from Earth.

Why is this significant?

• Coronal mass ejections (CMEs) are large expulsions of plasma and magnetic fields from the Sun.
• Earth-directed CMEs can disturb satellites, navigation, radio communications and electricity networks.
• Measuring their direction improves understanding of space weather. However, a Doppler image alone does not provide a complete prediction of an eruption’s effects on Earth.
• Their speed and magnetic-field strength influence how severely they may affect Earth.
• Early detection helps scientists issue warnings and prepare technologies that could be disrupted.

Why in news

• Researchers identified a naturally transmissible cancer in brown bullhead catfish (Ameiurus nebulosus) living in Lake Memphremagog, between Canada and the United States.

What was discovered?

• Around 30% of sampled fish were affected by melanoma, a cancer arising from pigment-producing cells called melanocytes.
• Genetic comparisons showed that tumours in different fish were more closely related to one another than to their respective hosts.
• This indicates that cancer cells themselves moved between fish and established new tumours, rather than each fish independently developing the same cancer.
• Differences in mitochondrial DNA—the genetic material inside cells’ energy-producing structures—helped establish the tumours’ foreign origin.

How is this unusual?

• Most cancers arise from an individual’s own cells and do not spread between individuals.
• This is the fourth documented major type of naturally occurring transmissible cancer, following examples in dogs, Tasmanian devils and bivalve molluscs such as clams.
• It is the first identified in fish and freshwater environments.

Significance and limitations

• The discovery could help explain how foreign cells escape immune rejection, a question relevant to organ transplantation.
• The exact transmission route remains uncertain; transfer through water or physical contact is being investigated.
• The finding does not mean that ordinary human cancers are contagious.

Why in news

• An analysis of hourly global temperatures since 1960 has used the term “heat storm” to describe exceptionally extensive heatwaves.

What is a heatwave?

• A heatwave is a spell of unusually high temperatures compared with the normal conditions for a place and season.
• It can develop when persistent high pressure causes air to sink, suppresses cloud formation and allows heat to accumulate.
• The same temperature can represent extreme heat in one region but normal weather in another. Definitions therefore consider local conditions.

Heatwave criteria in India

• The India Meteorological Department (IMD) considers both the actual maximum temperature and its departure from normal, meaning how much hotter it is than the expected temperature.

• For the departure-based criterion, the actual maximum temperature must reach at least 40°C in the plains or 30°C in hilly regions.
• At coastal stations, a heatwave may be declared when the maximum temperature reaches at least 37°C and is 4.5°C or more above normal.
• For a meteorological subdivision, qualifying conditions must occur at at least two stations for two consecutive days; the declaration is made on the second day.
• Example: If a plains station normally records 36°C but reaches 41°C, its departure is 5°C, meeting the station-level heatwave criterion.

What is a heat storm?

• The approach connects neighbouring areas experiencing unusually high temperatures into a single evolving event.
• Under this analytical definition, an event becomes a heat storm when it covers at least 1% of Earth’s surface at some point.
• The term describes widespread heat; it does not imply the winds or rainfall associated with a conventional storm.
• It is an analytical naming framework, rather than a universally adopted meteorological classification.

What are heat cascades?

• Heat cascades occur when large heat events follow one another, overlap or occur simultaneously.
• Their average duration increased from roughly two months in the 1960s to nine months in the early 2000s.
• The event named Vera lasted 367 days during 2023–24, affecting nearly 85% of the globe cumulatively over its lifetime, rather than all at once.

Why does this matter?

• Connected heat events can affect agriculture, water availability, electricity demand and human health across several regions.
• Tracking their movement and overlap can improve early warnings and coordination when multiple countries face extreme heat together.
• They can strain healthcare systems by increasing heat-related illness, hospital admissions and mortality.
• Simultaneous heatwaves can reduce food production and disrupt supply chains across multiple agricultural regions.
• High temperatures can worsen drought conditions by increasing evaporation and water demand.
• Heat can damage roads, railways, power lines and other critical infrastructure.
• Rising electricity demand for cooling can increase the risk of power shortages and blackouts.
• Identifying connected events can help governments target resources, coordinate emergency responses and protect vulnerable communities.
• Understanding these patterns can improve climate models and support long-term adaptation planning.

Why in news

• Japan launched the Martian Moons eXploration (MMX) mission on 20 October 2026, aiming to return the first samples from a Martian moon.

Mission essentials

What will it investigate?

• Scientists want to establish whether the moons are captured asteroids or formed from debris produced by a major collision involving Mars.
• Regolith, the loose dust and broken rock covering a celestial body, preserves clues about its composition and history.
• Material blasted from Mars by past impacts may also have reached Phobos, potentially providing information about the planet.

Why is sample return important?

• Laboratories on Earth can conduct more detailed tests than instruments carried aboard a spacecraft.
• The mission will also develop technologies for operating and collecting samples in extremely weak gravity.

Why in news

• State Bank of India identified 3,897 customer records within a larger dataset of approximately 3.75 lakh records circulating on the dark web. The bank began examining the authenticity, origin and extent of the exposure.
• In a separate case, the Kerala High Court directed SBI to refund ₹3.73 lakh to a cyberfraud victim who had promptly reported the unauthorised transaction.

What makes a data breach dangerous?

• Personally identifiable information includes details that identify someone, such as their name, mobile number, address, date of birth and Permanent Account Number.
• Criminals can combine leaked information to impersonate a bank employee and make fraudulent calls or messages appear convincing.
• Phishing involves tricking people into revealing credentials or opening fraudulent websites and applications.
• The larger dataset’s size does not establish that every record belonged to an SBI customer.

Customer protection

• Prompt reporting, effective fraud monitoring and timely reversal of eligible transactions are essential. The court’s decision does not create an unconditional refund entitlement for every phishing case.

Why in news

• Eight private keys associated with eMudhra’s certificate infrastructure were exposed. A key is a piece of information used by cryptographic algorithms to encrypt, decrypt, sign, or verify data. Six affected certificates related to website security and were trusted through major browser and operating-system programmes.
• The company revoked affected certificates and began investigating the failure.

How do digital certificates work?

• A digital certificate is like a digital ID card for a website. It connects the website’s name with its public key.
• A trusted Certificate Authority (CA) checks the website and signs its certificate. When you visit the site, your browser checks this signature to make sure the certificate is trustworthy and has not been changed.
• The public key can be shared openly. The matching private key must be kept secret. The private key helps the website prove that it is the real owner of the certificate.
• Transport Layer Security (TLS), which is used by HTTPS, does two main things: it confirms that you are connected to the correct website, and it encrypts the information sent between your browser and the website.
• A root authority is the highest level of trust. It can approve intermediate authorities, which then issue certificates to websites. This creates a chain of trust from your browser to the website.

What went wrong?

• The system was supposed to create strong 384-bit private keys. Instead, it created very small numbers, ranging from 1 to 256. Because there were so few possible values, an attacker could easily guess the keys.
• Signing keys are used to prove that a certificate is genuine. If an attacker can guess or obtain these keys, they may be able to create fake certificates and pretend to be a trusted website or organization.
• eMudhra said that only one affected intermediate certificate authority was used in its live production system. It also said that this authority had not issued any certificates to end users, which limited the possible impact.

Significance

• There was no indication that the root certificates themselves were compromised.
• Domestic digital-signature and eSign services were reported unaffected. Their regulatory and technical arrangements must be distinguished from website-security certificates.
• Devices that rarely receive updates can remain vulnerable even after browsers remove trust in affected certificates.

Why in news

• Reported restrictions on Ukraine’s access to the Starshield satellite network have renewed concerns about foreign control over critical technological services.

Where does dependence arise?

Important concepts

• Technological sovereignty means having sufficient control over essential technology to maintain services despite external pressure.
• Data localisation means storing data within a country. It does not automatically provide control over the software or management infrastructure.
• Vendor lock-in occurs when switching suppliers becomes difficult because systems depend heavily on one provider’s technology.

India’s position

• A July 2026 assessment indicated that only three NavIC satellites could provide positioning, navigation and timing signals. Standard standalone satellite positioning requires at least four.
• By December 2025, 2,170 ministries and departments were hosting applications on the government’s MeghRaj cloud, although private providers also remained involved.
• The Unified Payments Interface provides domestic payment infrastructure. The closure of one payment application would not itself shut down UPI.

Way forward

• Reliable domestic alternatives, diversified suppliers, interoperable systems and open-source software can reduce dependence.
• Resilience also requires replacement components, maintenance capability and practical plans for continuing essential services during disruptions.

Why in news

• An assessment of 244 tribal districts identified substantial opportunities for expanding pulses and oilseeds on suitable lands recognised under the Forest Rights Act.

What does the Forest Rights Act provide?

• The Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006 addresses the historical non-recognition of forest communities’ rights. The Ministry of Tribal Affairs is its nodal ministry.

Agricultural potential

• The assessment identified 60 districts with major oilseed potential, 31 with strong pulse potential and 23 suitable for both.
• Suitable crops include groundnut, mustard, soybean, chickpea and lentil, depending on local soils, rainfall and farming practices.
• Pulses can improve soil fertility through biological nitrogen fixation. Appropriate crop diversification can also improve nutrition and reduce exposure to a single crop’s failure.

What support is needed?

• Land recognition must be accompanied by quality seeds, soil and water conservation, extension services, affordable credit and crop insurance.
• Farmer Producer Organisations, cooperatives and self-help groups can support storage, processing and collective marketing.
• Agricultural support programmes should converge around local requirements while preserving community rights, biodiversity and traditional knowledge.
• The central issue is converting secure land rights into sustainable livelihoods without encouraging unsuitable cultivation or ecological damage.

Why in news

• The Index of Core Industries grew 7.9% in September 2026, compared with the corresponding month a year earlier.
• August’s growth was revised from 4.8% to 5.9%, while cumulative growth during April–September reached 5.1%.

What does the index measure?

• The Office of the Economic Adviser, under the Department for Promotion of Industry and Internal Trade (DPIIT), Ministry of Commerce and Industry, compiles and releases the Index of Core Industries every month.
• The index tracks production in industries that supply important inputs to the wider economy.
• The revised series uses 2022–23 as its base year and covers nine industries, including iron ore.
• These are coal, crude oil, natural gas, refinery products, fertilisers, steel, cement, electricity and iron ore.
• Electricity has the largest weight, followed by refinery products and steel. Consequently, equal growth rates across industries do not contribute equally to the overall index.

September’s performance

• Iron ore grew 18.4%, electricity 11.4%, coal 10.7% and refinery products 10.3%.
• Fertilisers, natural gas and crude oil contracted.

Why does it matter?

• The index offers an early indication of activity in energy, construction and industrial supply chains.
• It measures production rather than prices, employment or the entire economy.
• Historical comparisons must account for changes in the base year, industry coverage and weights.

Why in news

• The Indo-Tibetan Border Police confirmed continuing confrontations at several locations in Arunachal Pradesh.
• Reports placed a stand-off near Asaphila and Taksing in Upper Subansiri district, where Chinese troops reportedly established tents around 6–7 kilometres inside India’s perception of the Line of Actual Control.

Understanding the dispute

• The Line of Actual Control (LAC) separates areas under Indian and Chinese control. Its alignment is not mutually agreed along the entire boundary.
• Different perceptions of the LAC create overlapping patrol areas, where troops can come face to face.
• India recognises the McMahon Line as its boundary in the eastern sector. China disputes this boundary and claims territory in Arunachal Pradesh.

Border-management mechanisms

• The Working Mechanism for Consultation and Coordination brings diplomatic and military officials together to address border issues.
• Special Representatives’ talks address the wider boundary question, while military commander meetings seek to resolve situations on the ground.
• Agreements signed in 1993 and 1996 established commitments to maintain peace and military confidence along the LAC.

Role of the ITBP

• The Indo-Tibetan Border Police (ITBP) is a Central Armed Police Force under the Ministry of Home Affairs.
• Its Shaurya commandos are being developed as a specialised force for high-altitude operations.
• The situation highlights the importance of surveillance, logistics, modern equipment and communication alongside diplomatic engagement.

Why in news

• A study examined whether consuming sugar-rich foods during antibiotic treatment could worsen disruption of the gut microbiome.

Essential concepts

• The gut microbiota consists of microorganisms living in the intestine. They assist digestion, metabolism and immune functions.
• Dysbiosis means disruption of this microbial community, including reduced diversity or excessive growth of particular organisms.
• Antibiotics may suppress helpful bacteria along with disease-causing bacteria, reducing competition within the gut.

What the study found

• Researchers recorded 9,419 meals consumed by 173 patients undergoing blood stem-cell transplantation.
• They analysed 1,009 stool samples from 158 patients with matching dietary and microbiome information.
• Higher consumption of sweets during broad-spectrum antibiotic exposure was associated with lower microbial diversity and greater abundance of Enterococcus faecium.
• In mice, sucrose combined with an antibiotic produced approximately 16-fold higher Enterococcus levels by day three and 33-fold higher levels by day six, compared with antibiotic treatment alone.

Significance and limitations

• The findings show how food, medicines and microorganisms interact during treatment.
• Enterococcus faecium can cause difficult-to-treat infections, particularly in vulnerable patients.
• The human findings were observational and involved seriously ill patients. They do not establish that the same effects occur in everyone taking antibiotics.
• Clinical trials are needed before translating these findings into routine dietary recommendations.

Why in news

• Advances in detecting chemical signatures are improving the identification of diseases, especially those affecting the brain and nervous system.

What are chemical signatures?

• They are measurable patterns of proteins, antibodies or other substances that provide clues about biological processes.
• A biomarker is a measurable indicator of a normal process, disease or response to treatment.
• Biomarkers can be detected in blood, tissues or cerebrospinal fluid, which surrounds the brain and spinal cord.

Why interpretation matters

• Sensitivity describes how well a test detects people who have a condition. Specificity describes how well it excludes those who do not.
• Age, kidney function, medicines and other illnesses can influence results.
• Biomarkers must be interpreted alongside symptoms, examination and other investigations. For example, an authorised Alzheimer’s blood test is intended to assist diagnosis rather than serve as a standalone screening test.

Significance

• Reliable biomarkers can support earlier diagnosis, distinguish similar conditions and guide treatment.
• Cost, laboratory quality and limited availability remain major barriers to wider access.

Why in news

• Preliminary rocket-motor tests of Jwala-Mk1 have drawn attention to indigenous counter-drone technology and the cost of air defence.

What is Jwala-Mk1?

• It is a short-range surface-to-air missile being developed by IG Defence, an Indian private defence company.
• Its intended purpose is to destroy hostile unmanned aerial vehicles, commonly called drones.
• Its stated engagement range is 2–5 kilometres, with an altitude envelope of 50–5,000 metres.
• It uses a dual-pulse solid rocket motor: separate thrust pulses support initial acceleration and additional energy during interception.

Why interception costs matter

• A relatively inexpensive drone can force a defender to launch a much more expensive missile.
• Repeated attacks can therefore exhaust both ammunition and financial resources.
• The relevant measure is the cost per successful interception, which includes detection, launch, reliability and maintenance.

Development status and significance

• On 3 October 2026, the company reported testing two solid rocket motors.
• These tests do not establish operational readiness. Full-system flight trials, guidance validation and realistic interception tests remain necessary.
• The project’s value will depend on reliable interception, affordable lifetime costs and production at sufficient scale.

Other air-defence systems of India

• Short-range: Akash; Quick Reaction Surface-to-Air Missile (QRSAM); Surface-to-air Python and Derby (SPYDER).
• Medium-range: Medium-Range Surface-to-Air Missile (MRSAM/Barak-8).
• Long-range: S-400 Triumf.

Why in news

• The fifth edition of Kashi Tamil Sangamam will take place from 28 November to 12 December 2026, with Thirukkural as its central theme.

About the programme

• It seeks to strengthen historical links between Tamil Nadu and Kashi, encouraging exchanges involving language, learning, arts and traditions.
• The first edition was held in 2022.
• The Department of Higher Education organises it with institutions including IIT Madras, Banaras Hindu University and the Central Institute of Classical Tamil.
• Around 1,400 participants, divided into seven groups, will visit Varanasi, Prayagraj and Ayodhya. Activities across 1,000 higher education institutions will promote engagement with Thirukkural.

About Thirukkural

• Thiruvalluvar composed this classical Tamil work, which contains 1,330 couplets in 133 chapters.
• Its three divisions address Aram, meaning virtue; Porul, covering wealth and public affairs; and Inbam, dealing with love.
• Its teachings include justice, responsible leadership, compassion, learning and ethical conduct.

Significance

• The programme connects classical literature with contemporary education and public life.
• Thirukkural’s discussion of ethical leadership and just governance is particularly relevant to administrative ethics.

Why in news

• The Supreme Court held that private citizens can file criminal complaints against electoral candidates who furnish false information or conceal required information in their nomination documents.

What the judgment establishes

• A complaint need not come exclusively from a public servant or election authority.
• The restriction under Section 195 of the Code of Criminal Procedure, which requires complaints by specified authorities for certain offences, does not prevent private complaints under Section 125-A of the Representation of the People Act, 1951.
• This gives voters a direct legal route to challenge dishonest electoral disclosures.

Relevant provisions

• Section 33-A requires candidates to disclose specified criminal antecedents.
• The prescribed election affidavit, commonly called Form 26, also contains information about assets, liabilities and educational qualifications.
• Section 125-A penalises specified failures to furnish information, knowingly false disclosures and concealment in nomination documents.
• The punishment may extend to six months’ imprisonment, a fine, or both. The offence is non-cognisable and bailable.

What does non-cognisable mean?

• For a non-cognisable offence, the police do not have authority to arrest a person without a warrant merely on the basis of that offence.
• In a case involving only non-cognisable offences, the police also require an order from a competent Magistrate before investigating.
• A person can approach the Magistrate with a complaint, after which the court follows the prescribed procedure.
• Bailable means the accused is entitled to bail on fulfilling the applicable legal conditions. It does not mean the allegation is dismissed or the accused is acquitted.

Constitutional significance

• Voters’ right to know relevant information about candidates supports informed choice under Article 19(1)(a).
• Disclosure requirements strengthen electoral transparency and accountability.
• Filing a complaint does not establish guilt; the allegations must be proved through the judicial process.

Why in news

• An enhanced National Mobile Monitoring System (NMMS) application was launched to strengthen attendance verification under the Viksit Bharat–Guarantee for Rozgar and Ajeevika Mission Gramin (VB-G RAM G) rural employment programme.

Why the upgrade was needed

• Face authentication was introduced in March 2026, but attempts to bypass it continued.
• Reported irregularities included photographing existing photographs, reusing images across attendance records and recording incorrect worker counts.

Important features

How wage verification works

• Attendance alone does not determine payment.
• Technical personnel measure completed work and record it in an electronic Measurement Book.
• Suspicious entries can trigger withholding of the wage list and Fund Transfer Order until verification is completed.
• Eligible payments are transferred to workers’ bank accounts through Direct Benefit Transfer.

Scale and concerns

• Nearly 46 crore person-days had been generated, with about 40 crore recorded through face authentication.
• Work covered more than 2.41 lakh Gram Panchayats.
• Reliable exception handling, timely grievance resolution and protection of personal data are essential to prevent genuine workers from losing wages.

Why in news

• The debate concerns whether to enlarge the Lok Sabha and how parliamentary seats should be distributed among States.
• A proposal for a House of up to 850 seats, compared with the present 543 elected seats, has raised questions about population-based representation and federal balance.

Understanding the three separate decisions

• Increasing the House’s size means creating additional parliamentary seats.
• Reallocating seats among States means changing how many representatives each State receives.
• Redrawing constituency boundaries means changing the geographical area represented by an individual MP or MLA.
• These decisions can have different consequences. Boundaries can be redrawn without increasing a State’s total seats, as happened in the previous nationwide exercise.

Why delimitation is needed

• Population growth and migration can leave constituencies with very different populations.
• If one MP represents substantially more people than another, citizens’ votes carry unequal representational weight.
• Delimitation seeks reasonably balanced representation while considering administrative boundaries, geographical features, communication facilities and public convenience.
• It also determines constituencies reserved for Scheduled Castes and Scheduled Tribes under the applicable population framework.

Constitutional framework

• Article 81 governs the composition of the Lok Sabha and population-based representation.
• Article 82 provides for readjustment following a Census.
• Article 170 contains corresponding provisions for State Legislative Assemblies.
• Parliament enacts the relevant law, and a Delimitation Commission carries out the exercise. Its final orders have the force of law.
• An expansion beyond the existing constitutional ceiling would require a constitutional amendment.

Previous nationwide exercises

Why are seat allocations still linked to 1971?

• The 42nd Constitutional Amendment, 1976, froze population-based seat readjustment until after 2000.
• The intention was to prevent States pursuing population control from being disadvantaged through reduced representation.
• The 84th Amendment, 2001, extended the freeze until the relevant figures of the first Census taken after 2026 are published.
• The 87th Amendment, 2003, enabled the use of 2001 Census figures for boundary readjustment without changing the frozen seat totals.
• Consequently, crossing the year 2026 does not automatically redistribute seats; the constitutional Census and readjustment process must follow.

Connection with women’s reservation

• The 106th Constitutional Amendment, 2023, provides for approximately one-third reservation for women in the Lok Sabha and State Assemblies.
• Articles 330-A and 332-A establish the reservation framework.
• Article 334-A links implementation to delimitation after publication of the relevant Census figures.
• Increasing the total number of seats is a separate proposal; women’s reservation does not itself require an 850-seat House.

The federal dilemma

• Faster-growing States could receive a larger share of seats under a fresh population-based allocation.
• States that reduced population growth fear losing relative influence over national decisions.
• Enlarging the House while preserving each State’s percentage share would retain relative representation but increase differences in absolute seat numbers.
• For example, a State holding 10% of a 500-seat House has 50 seats; in an 800-seat House, the same share gives it 80 seats. Its number rises, but its percentage influence remains unchanged.

Why in news

• A counter-intelligence investigation named Operation Firewall 2026 uncovered an alleged network attempting to obtain sensitive Indian naval information through online manipulation.

Important findings

• Investigators identified 18 key suspects, including 13 naval personnel, across 10 States.
• Two people had been arrested at the stage described.
• The investigation examined alleged attempts to obtain information about naval movements, vessels, submarines and sensitive installations.
• Investigators suspected that some fabricated online identities used AI-generated material; this remained under examination.

How the alleged network operated

• Social engineering manipulates people into revealing information or performing actions that compromise security.
• Operatives allegedly used fictitious profiles to establish trust, gradually move conversations towards sensitive subjects and offer financial inducements.
• Honey-trapping uses a fabricated romantic or sexual relationship to gain influence over a target.
• Compromising material can subsequently be used for coercion or blackmail.

Important concepts

• Open-source intelligence uses publicly accessible information to identify targets and understand their interests or vulnerabilities.
• Deepfakes are synthetic or manipulated images, audio or videos that can imitate real people.
• Human intelligence relies on information obtained through people, while technical intelligence uses electronic interception and other technological methods.

Security implications

• AI can make impersonation more convincing and allow fraudulent identities to be produced at scale.
• Operational security requires restrictions on sharing sensitive information, prompt reporting of suspicious contact and regular awareness training.
• Digital evidence and alleged links must be independently established before criminal responsibility is determined.

Why in news

• A low-pressure system over the Bay of Bengal was expected to intensify and approach the southern Odisha–northern Andhra Pradesh coast by 28 October.
• It developed on 23 October. Some forecasts indicated winds reaching around 145 km per hour and a possible 1–2 metre storm surge.
• Its precise landfall location and final intensity remained uncertain.

What is a cyclone?

• A cyclone is a large atmospheric system in which winds circulate around a low-pressure centre.
• Near the surface, air moves towards the centre and rises.
• Rotation is anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere, because of the Coriolis effect.

How a tropical cyclone develops

• Warm ocean water supplies heat and moisture to the atmosphere.
• Moist air rises and cools, causing water vapour to condense into clouds.
• Condensation releases latent heat, which warms the surrounding air and sustains further rising motion.
• Surface pressure falls, drawing in more moist air and strengthening the circulation.
• Sufficient moisture, adequate Coriolis force and low vertical wind shear, meaning limited changes in wind with height, favour development.

Structure of a mature tropical cyclone

• Eye: This is the relatively calm central region, where air sinks. It can have comparatively clear skies and light winds, although sea conditions may remain dangerous.
• Eyewall: This ring of towering thunderstorm clouds surrounds the eye. It contains the strongest winds, vigorous rising air and some of the heaviest rainfall.
• Spiral rainbands: These curved bands of clouds extend outward from the centre and bring bursts of rain, thunderstorms and strong winds.
• Surface inflow: Air near the ocean spirals inward towards the low-pressure centre.
• Upper-level outflow: Air that has risen through thunderstorms spreads outward high in the atmosphere, helping maintain the circulation.
• Warm core: The cyclone’s central atmospheric column is warmer than its surroundings, largely because of heat released during condensation.
• A clearly defined eye develops mainly in sufficiently strong, organised cyclones; weaker systems may lack one.
• A temporary lull as the eye passes can be followed by a rapid return of dangerous winds from the opposite direction.

Storm surge and landfall

• A storm surge is an abnormal rise of seawater above the predicted astronomical tide, caused mainly by strong winds pushing water towards the coast.
• Low-lying coasts and shallow coastal waters can experience severe inundation.
• Landfall occurs when the cyclone’s centre crosses the coastline. Dangerous weather can begin well before this happens.

What is a temperate cyclone?

• A temperate cyclone, also called a mid-latitude or extratropical cyclone, usually develops where contrasting warm and cold air masses interact.
• The boundary between these air masses is called a front.
• A disturbance along the front can develop into a low-pressure system, assisted by favourable conditions in the upper atmosphere.

Structure and development of a temperate cyclone

• A warm front forms where advancing warm air rises over colder air.
• A cold front forms where advancing cold air pushes beneath warmer air, forcing it upward.
• The warm sector is the region of relatively warm air between these fronts.
• As the system develops, the cold front can catch up with the warm front, lifting warm air away from the ground and forming an occluded front.
• Clouds and rainfall are distributed unevenly around the fronts, often producing a comma-shaped cloud pattern.
• These systems can bring rain, thunderstorms, snowfall and widespread strong winds. Western Disturbances affecting India are associated with extratropical weather systems.

Eight important differences

• These are typical characteristics. A tropical cyclone can transition into an extratropical system as its environment and energy source change.

Why in news

• An alleged breach exposed certification-related documents concerning more than 500 film titles submitted through the Central Board of Film Certification’s e-Cinepramaan portal.
• Separately, the government ordered a security audit of transport portals following reports that personal information about vehicle owners was being sold online.

Which information was involved?

• The film-related material included scripts, certification documents and instructions for cuts. The alleged exposure did not include the feature films themselves.
• The transport-related information reportedly included names, addresses, mobile numbers, registration certificates and driving-licence details. Some services offered information for as little as ₹5.
• The film-certification authority said its preliminary examination had not established the claimed unauthorised access. A forensic investigation and security audit were therefore important before determining responsibility.

What do the transport portals do?

• VAHAN provides services related to vehicle registration.
• SARATHI provides services related to driving licences.
• e-Challan records traffic violations and supports payment of fines.
• PUCC manages Pollution Under Control certificates for vehicles.

Important concepts

• A data breach involves unauthorised access to, disclosure of or loss of protected information.
• A forensic security audit examines technical records, access logs and system behaviour to establish how information may have been accessed.
• Access control limits what each user or organisation can view. Data minimisation restricts sharing to information genuinely required for a particular purpose.
• Authorised access can also be misused. An exposure need not always result from an external hacker breaking into a server.

Why it matters

• Transport-data access credentials had reportedly been issued to 25,314 private entities, through which approximately 1.708 crore queries were made over 33 months.
• Combining identity and contact information can enable impersonation, targeted fraud and unwanted surveillance.
• The Indian Computer Emergency Response Team (CERT-In) coordinates responses to cybersecurity incidents. Effective protection also requires monitoring authorised users, reviewing permissions and investigating unusual bulk searches.

Why in news

• Prolonged deployment for electoral-roll revision has disrupted teaching and anganwadi services in Karnataka.
• A proposed legislative safeguard would make teachers the last option for non-teaching assignments after other personnel have been considered.

Scale of the deployment

• Karnataka appointed 59,050 Booth Level Officers (BLOs) for the Special Intensive Revision of electoral rolls.
• The exercise began on 30 June, while publication of the final rolls was postponed from 7 October to 27 October.
• A teachers’ association estimated that around 70,000 personnel were engaged as BLOs and supervisors. This broader estimate should not be treated as the number of teachers deployed.
• Teachers and anganwadi workers reported difficulties maintaining classroom instruction, early-childhood activities and other welfare responsibilities.

What does a BLO do?

• A BLO assists with maintaining accurate electoral rolls within an assigned polling area.
• The work includes household verification, identifying eligible voters and helping process additions, corrections and deletions.
• Accurate rolls are essential, but prolonged assignments can reduce the time available for the employee’s regular public-service duties.

Constitutional and legal position

• Article 21A guarantees free and compulsory education to children aged 6–14 years.
• Section 27 of the Right to Education Act, 2009, generally prohibits deploying teachers for non-educational purposes. This means that teachers should ordinarily be engaged in teaching, lesson preparation, assessment, student support and other activities directly connected with education, rather than being assigned unrelated administrative or government duties.
• It permits exceptions for the decennial population census, disaster relief and elections to local authorities, State Legislatures and Parliament.
• Election work is therefore a permitted exception, but its organisation must still account for children’s educational needs. In practice, authorities should plan election-related duties in a way that minimises disruption to classes, avoids unnecessary teacher deployment and ensures that students continue to receive their education.

Proposed safeguard

• District administrations would first identify available non-teaching employees, retired personnel and trained volunteers.
• Deploying a teacher would require certification that suitable alternatives were unavailable.
• The proposal remains distinct from an enacted protection. Staffing shortages, replacement teachers and clear limits on deployment remain important implementation issues.

Why in news

• The government plans to strengthen a Civil Defence Network through specialised training supported by the Indian Army.
• The first phase proposes training 600 master trainers from 12 States and Union Territories, with 50 participants from each.

What is civil defence?

• Civil defence protects civilians, property and essential services against hostile attacks and emergencies.
• Its activities include warning people, organising evacuation, providing first aid, conducting rescue operations and supporting continuity of essential services.
• The Civil Defence Act, 1968, provides the legal framework. Its scope was subsequently expanded to include disaster-management responsibilities.
• Civil defence involves civilian protection and assistance; it does not turn volunteers into combat troops.

Training programme

• The three-day programme is planned by the second week of November at designated Army training establishments.
• Training will include chemical, biological, radiological and nuclear (CBRN) awareness, covering hazards such as toxic chemicals, infectious agents and radioactive contamination.

Significance

• Master trainers can pass their skills to larger civilian networks, improving local preparedness.
• Common procedures can reduce confusion when several agencies respond to the same emergency.
• Training must be supported by equipment, regular exercises, clear responsibilities and arrangements for protecting vulnerable people.

Why in news

• A study by scientists associated with the India Meteorological Department and Indian Institute of Tropical Meteorology examined changes in India’s climate zones.
• It linked some changes in northern India’s rainfall and moisture supply with the Victoria Mode, a Pacific Ocean temperature pattern.

What is the Victoria Mode?

• It is a recurring pattern of contrasting warm and cool sea-surface temperatures in the North Pacific.
• Such temperature patterns can influence atmospheric circulation far beyond their place of origin.
• This distant influence is called a teleconnection. Changes over an ocean can alter winds and moisture transport over another region.
• The Victoria Mode is distinct from El Niño, which develops in the tropical Pacific, and from the Pacific Decadal Oscillation, another pattern of Pacific variability.

Changes identified in the study

• In northwest India, the hot semi-arid steppe zone increased from 25.7% of the region in 1951–80 to 33.1% in 1991–2020.
• The temperate zone there declined from 25.8% to 18.7%.
• In peninsular India, the semi-arid steppe share fell from 30.3% to 16.4%, while tropical savannah increased from 61.6% to 75.7%.
• These findings show that climatic changes vary across regions rather than producing uniform drying throughout India.

Understanding the climate zones

• A steppe climate is semi-arid: rainfall is limited, but conditions are generally less dry than in a desert.
• A tropical savannah climate remains warm throughout the year and has a distinct dry season.
• Climate classification considers long-term temperature and rainfall patterns. A single unusually hot or dry year does not establish a permanent change of climate zone.

Why it matters

• Changing rainfall and moisture availability affect crop suitability, water demand and drought risk.
• Oceanic variability interacts with global warming and other influences. The study should not be read as establishing one exclusive cause of every regional change.

Why in news

• Exceptional warming in the central equatorial Pacific has raised concerns about a strong 2026–27 El Niño and its effects on heat, rainfall and water availability.
• Observations included a Niño 3.4 sea-surface temperature of 30.06°C on 5 October and a temperature anomaly of 3.48°C on 18 October.

What is El Niño?

• El Niño is the warm phase of the El Niño–Southern Oscillation (ENSO), a coupled ocean–atmosphere system.
• Normally, trade winds push warm surface water westwards across the tropical Pacific.
• During El Niño, these winds weaken, allowing warm water to spread towards the central and eastern Pacific.
• The resulting changes in ocean temperatures and atmospheric circulation shift rainfall and weather patterns across the world.

Understanding Niño 3.4

• Niño 3.4 is a monitoring region extending approximately from 5°N to 5°S and 170°W to 120°W.
• A temperature anomaly is the difference between an observed temperature and the long-term average for that period.
• An absolute temperature of 30°C and an anomaly of 3°C describe different things.
• El Niño identification requires persistent warming and a corresponding atmospheric response. One exceptionally warm day is insufficient.

Possible consequences

• El Niño usually transfers additional ocean heat into the atmosphere, temporarily increasing global temperatures.
• It often weakens India’s southwest monsoon, but the relationship is not identical in every event.
• Other oceanic patterns, regional circulation and global warming can strengthen or offset its effects.
• The event was projected to peak around December, with a seasonal anomaly of approximately 3.8°C. This is a forecast rather than an already observed seasonal value.

Preparedness

• Heat-action plans, reservoir management, crop advisories and reliable seasonal forecasts can reduce damage.
• The strength of El Niño alone does not determine the severity of every local impact.