Rapid urbanisation, loss of wetlands, and concretisation disrupt natural drainage in Indian cities.

About Hydrological Hysteresis and Landscape Memory

• Hydrological Hysteresis: It describes how a landscape’s response to rainfall depends on the current volume of rainfall as well as on past events.
• Landscape Memory: Landscapes do not absorb rain instantly or dry up immediately. They retain a memory of past precipitation, dictating current soil saturation levels.
• Urban Flooding Context: Prolonged waterlogging in Indian cities isn't solely a drainage failure. 
• Because of hysteresis, previously saturated landscapes cannot absorb new rainfall, leaving surface water trapped on city streets.

The current account deficit has moderated to 30.1 billion dollars in the period of April-December 2025 from 36.6 billion dollars in the same period a year ago.

About CAD

• CAD refers to the situation where a country's total imports of goods, services, and transfers exceed its total exports and transfers out.
• It encompasses: Goods and services and also income received from investments abroad and unilateral transfers, such as remittances and foreign aid.
• CAD is part of the broader balance of payments framework, which tracks all financial transactions between a country and the rest of the world.

India has renewed its Bilateral Swap Arrangement BSA (Currency Swap Arrangement) with Japan with effect from 28th February, 2026.

• The BSA is a two-way arrangement where both authorities can swap their local currencies in exchange for the US Dollar.
  • A currency swap is a broader term defined as an agreement between two central banks to exchange a cash flow in one currency against a cash flow in another currency according to predetermined conditions.
• The size of the India-Japan BSA: Remains unchanged at 75 billion US Dollars. 
• Other CSAs by India: SAARC CSA (2024-27),India-UAE CSA, India-Sri Lanka CSA, etc. 

A new study overturns a model of bacterial gene regulation based on the so-called “σ (sigma) cycle” and unveils new paths for understanding bacterial gene regulation and its evolution.

σ (sigma) cycle

• sigma (σ) cycle” was considered as a universal mechanism governing bacterial gene activation. 
• According to this long-accepted model, sigma factors bind to RNA polymerase to initiate transcription, the process by which genetic information is copied into RNA and then detached to allow the transcription process to continue. 
• The theory was largely based on studies of the bacterium Escherichia coli and its sigma factor, known as σ70.

The Supreme Court has decided to look into whether blood banks should compulsorily conduct the Nucleic Acid Test (NAT) for identification of diseases.

About NAT

• NAT is a highly sensitive molecular technique that detects the genetic material for viruses such as HIV, Hepatitis in the blood.
• It is based on amplification of targeted regions of viral ribonucleic acid or deoxyribonucleic acid (DNA).
• It can be an alternative to commonly used Enzyme-Linked Immunosorbent Assay (ELISA) test.

IAEA held an emer­gency meeting in Vienna to address the fallout of US-Israel military strikes.

About IAEA:       

• Formed: in 1957.
• Overview: It is the world's central intergovernmental forum for scientific and technical cooperation in the nuclear field. 
• Function: It works for the safe, secure and peaceful uses of nuclear science and technology, contributing to international peace and security and the United Nations' Sustainable Development Goals.
• Headquarters: Vienna(Austria).
• Award: Nobel Peace Prize in 2005.

The Union Finance Minister met the President of the AIIB to discuss strengthening the India-AIIB partnership.

About AIIB:

• Established: in 2016
• Objective: it is a multilateral development bank that provides financing for infrastructure projects in Asia.
• Headquarters: Beijing, China
• Membership: Open to all members of the World Bank or Asian Development Bank.
• India is a founding member of AIIB.

India is set to witness a total lunar eclipse, confirms the Indian Meteorological Department.

About Total Lunar Eclipse:

• It occurs when the Moon passes entirely through Earth’s umbra (darkest part of its shadow), with the Earth, Sun, and Moon perfectly aligned, completely blocking direct sunlight.

About Blood Moon:

• Meaning: A Blood Moon refers to the reddish appearance of the Moon.
• Occurs: During total lunar eclipses,
• Cause of Formation:This happens because of the Earth's atmosphere.