About Blaze Star:

• Blaze Star, officially known as T Coronae Borealis (T CrB), is a dim star located 3,000 light-years away from our solar system. 
• It is found in the constellation Corona Borealis (the “Northern Crown”).
• The Blaze Star is a rare example of a recurrent nova, occurring once in every 80 years.
• Stellar components: The nova involves a binary star system comprising a white dwarf and a red giant. 
  • The white dwarf draws material from the red giant, leading to periodic explosive increases in brightness.
  •  The explosion occurs when the red giant’s surface temperature escalates dramatically, causing it to shed material onto the white dwarf, which then ignites a thermonuclear explosion.
• The upcoming stellar explosion is expected to be visible with the naked eye and shine as brightly as Polaris, the North Star, for about a week. 
  • NASA predicts this event to occur sometime between now and September 2024.
• Past notable eruptions of T CrB were recorded in the years 1946 and 1866, with earlier documented observations dating back to 1787 and 1217.
• Frequency and Impact: Novae like T CrB occur once every few decades to a century, differing from supernovae in scale, frequency, and consequences. 
  • Unlike supernovae, novae do not destroy the star system but allow it to reset and repeat the cycle.

Q1. What is a Chandrasekhar limit?

The Chandrasekhar limit is the maximum mass of a stable white dwarf star, approximately 1.4 times the mass of the Sun, beyond which it collapses into a neutron star or black hole.

Source: A 'new star' could appear in the sky any night now. Here's how to see the Blaze Star ignite.

About Tmesipteris oblanceolate:

• It is a rare species of fern which grows primarily on the ground or atop fallen tree trunks on the island nation of New Caledonia (an overseas French territory situated in the Southwest Pacific), and on neighboring islands such as Vanuatu.
• It is a small plant, typically 10-15 centimeters (4-6 inches) in height.
• It has a record-breaking genome size of 160.45 billion base pairs (Gbp), the units that make up a strand of DNA, 11 billion more than the previous record holder, the Japanese flowering plant Paris japonica, and 50 times more than the human genome.
  • If stretched out like from a ball of yarn, the length of the DNA in each cell of this fern would extend nearly 350 feet (106 meters). The human genome would extend a mere 6-1/2 feet (2 meters).
• Tmesipteris is a small genus of ferns whose ancestors evolved about 350 million years ago — well before dinosaurs set foot on Earth.
• It is distinguished by its mainly epiphytic habit (it grows mainly on the trunks and branches of trees) and restricted distribution in Oceania and several Pacific Islands.

What are Ferns?

• Ferns are plants that do not have flowers.
• Similar to flowering plants, ferns have roots, stems, and leaves.
• However, unlike flowering plants, ferns do not have flowers or seeds; instead, they usually reproduce sexually by tiny spores or sometimes can reproduce vegetatively.

Q1: What is Genome?

A genome is the complete set of genetic information in an organism. It provides all of the information the organism requires to function. In living organisms, the genome is stored in long molecules of DNA called chromosomes. Small sections of DNA, called genes, code for the RNA and protein molecules required by the organism. In eukaryotes, each cell's genome is contained within a membrane-bound structure called the nucleus. Prokaryotes, which contain no inner membranes, store their genome in a region of the cytoplasm called the nucleoid. The full range of RNA molecules expressed by a genome is known as its transcriptome, and the full assortment of proteins produced by the genome is called its proteome.

Source: Humble fern from New Caledonia boasts world's largest genome

About Dnipro:

• Formerly referred to as Dnipropetrovsk, Dnipro is a city of regional significance located in the Dnipropetrovsk Oblast, in the eastern portion of Ukraine. 
• It covers an area of 409,718 sq. km and is situated along both the banks of the Dnieper River, close to its meeting point with the Samara River. 
  • The city center stands on the right bank, which forms a part of the Dnieper Upland, while the left bank forms a part of the Dnieper Lowland. 
• It is the country's fourth-biggest city after the cities of Kyiv, Kharkiv, and Odesa.
• As of 2021, the city of Dnipro had a population of 980,948 inhabitants.
• It is considered one of the principal industrial centers of Ukraine.
  • The city hosts several facilities devoted to heavy industries producing various products, including launch vehicles, rolled metal, cast iron, machinery, agricultural equipment, different chemicals, etc. 

Key Facts about Dnieper River:

• It is the fourth-longest river in Europe (after the Volga, the Danube, and the Ural). 
• In Russian, the river’s name is Dnepr. In Ukrainian, it is Dnipro, and in Belarusian, it is Dnyapro.
• Located in Eastern Europe, the Dnieper River and its tributaries drain much of Belarus and Ukraine.
• Course:
  • It originates in Russia, in the low Valday Hills, west of Moscow.
  • It runs a total length of 1,368 miles through western Russia, Belarus, and Ukraine before emptying into the Black Sea.
  • It passes through numerous urban centers, such as the Russian cities of Smolensk and Dorogobuzh, as well as Mogilevin Belarus and Kiev, Cherkasy, Dnipro, and Zaporizhia in Ukraine.
• Historically, the river was an important barrier dividing Ukraine into right and left banks.
• Tributaries: It has as many as 32,000 tributaries, including the Sozh, Desna, Trubizh, Bilozerka, Drut, Berezina, and Prypiat Rivers. 

Q1: Which all countries border Ukraine?

Ukraine shares the border with seven other countries: Poland, Slovakia, Hungary, Romania, Moldova, Russia, and Belarus.

Source: Russian missile attack on Ukraine’s Dnipro injures seven people, including two children

About Neo:

• Discovery of 'Neo': It was reported by researchers led by Stephen Tang and Samuel Sternberg in a 2023 preprint paper on bio Rxiv while working on Klebsiella pneumoniae. 
• Mechanism: Bacteria defend themselves from viral infection (against bacteriophages) using diverse immune systems, many of which sense and target foreign nucleic acids. Defense-associated reverse transcriptase (DRT) systems are one of them. 
• In the DRT-2 system, the bacteria undergo de novo gene synthesis via rolling-circle reverse transcription (RT) of a non-coding RNA (ncRNA). 
• In uninfected bacterial cells, the ncRNA and RT enzyme lead to the synthesis of a repetitive single-stranded cDNA. 
• The presence of phage triggers the second-strand cDNA synthesis, leading to the production of long double-stranded DNA. 
• This double-strand cDNA generates messenger RNAs that encode a stop codon-less, never-ending open-reading frame (neo) whose translation (neo protein) causes potent growth arrest (cell dormancy) of bacteria. It protects the larger bacterial population from the spread of phage.
• Significance in Biotechnology and Medicine:
  • It represents a potential biotechnological tool for controlling viral infections.
  • Retroelements in the human genome and bacterial reverse transcriptases have a common evolutionary history as well as share functional mechanisms. 
  • Bacterial reverse transcriptases, believed to be the precursors of their eukaryotic counterparts, exhibit analogous mechanisms.
• Reverse transcriptase: 
• The ability of cells to create DNA copies from RNA is called reverse transcription. It is performed by the enzyme called reverse transcriptase. 
• Reverse transcriptase, discovered by Howard Temin and David Baltimore in 1970, has revolutionised research methods in molecular biology and is crucial in studying and managing RNA viruses like HIV.
• Reverse transcriptase is used in molecular biology to clone genes, perform PCR, and analyse genomes. 

It is also used in diagnostics to detect and quantify viral loads, such as in the case of SARS-2. It also has helped track the virus’s spread, paving the way for surveillance, better public healthcare, and vaccine development.

Q1. What is a DNA?

DNA (Deoxyribonucleic Acid) is a molecule that carries genetic information, responsible for transmitting hereditary traits from parents to offspring. It is a double helix structure composed of nucleotides with four nitrogenous bases: adenine, cytosine, guanine, and thymine.

Source: The bacteria that write new genes to cope with infections

About Rhine River:

• It is the 12th longest river in Europe and the longest in Western and Central Europe.
• It is called different names depending on the country it flows through. It is called Rhein in Germany, Rhine in France, and Rijn in Netherlands.
• It runs for over 1,232 km (766 miles) from its source in the Swiss Alps (in Switzerland).
• It flows through six countries -Switzerland, Principality of Liechtenstein, Austria, Germany, France and the Netherlands before flowing into the North Sea at Rotterdam, Netherlands.
• The Rhine forms a natural border between Germany and France.
• The river drains an area of about 185,000 square kilometres.
• Tributaries: Some of the notable tributaries of the Rhine River include Aare, Tamina, Moselle, Erft, Rein da Tuma, Plessur, Rotach, and Wiese.
• It is Europe's most important commercial waterway, channeling the flow of trade among Switzerland, France, Germany, and the Netherlands.
• The major cities along the Rhine include Basel (Switzerland), Cologne, Bonn, Duisburg, Mainz, Leverkusen, and Neuss (Germany), Strasbourg (France), and Rotterdam and Utrecht (Netherlands).
• It facilitates industrial transportation and supports industrial production, with about 20% of the world’s chemical industries manufacturing along the river. 

Q1: Which countries border the North Sea?

The countries that surround the North Sea include the United Kingdom, France, Belgium, the Netherlands, Germany, Denmark, and Norway.

Source: River Rhine in Germany closed to shipping after rain raises water level

About Parengyodontium album:

• It is a marine fungus that can break down plastic polyethene (PE), the most common plastic in the ocean.
• It was discovered by Marine microbiologists from the Royal Netherlands Institute for Sea Research (NIOZ).
• In this bioremediation process, the PE-derived carbon is converted into the fungal biomass of P. album, serving as its energy source. 
• Initial photodegradation of PE by UV sunlight is crucial for this process. It makes the fungus useful to degrade the floating oceanic plastic litter. 
• Humans produce over 400 billion kilograms of plastic annually, much of which ends up in the ocean.

Considering fungi as the ‘masters of degradation’ that they utilise a plethora of digestive enzymes for plastic degradation, researchers expect that there could be more plastic-degrading fungi in the deeper parts of the ocean.

Q1. What is the bioremediation process?

Bioremediation is a process that uses microorganisms, fungi, or plants to break down pollutants in soil, water, or air, converting them into non-toxic substances through natural biological processes.

Source: Fungus Breaks Down Plastic Polyethylene in the Ocean