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Subject: Basic Sciences

  • FELUDA test for Covid-19

    Union Health Ministry will soon roll out the FELUDA paper strip test for SARS-CoV-2 diagnosis.

    Try this PYQ:

    Q.What is Cas9 protein that is often mentioned in news?

    (a) A molecular scissors used in targeted gene editing

    (b) A biosensor used in the accurate detection of pathogens in patients

    (c) A gene that makes plants pest-resistant

    (d) A herbicidal substance synthesized in genetically modified crops

    FELUDA test

    • FELUDA is the acronym for FNCAS9 Editor Linked Uniform Detection Assay.
    • It uses indigenously developed CRISPR gene-editing technology to identify and target the genetic material of SARS-CoV2, the virus that causes Covid-19.
    • According to CSIR, the test matches accuracy levels of RT-PCR tests, considered the gold standard in the diagnosis of Covid-19, has a quicker turnaround time and requires less expensive equipment.
    • It is also the world’s first diagnostic test to deploy a specially adapted Cas9 protein to successfully detect the virus.

    How does it work?

    • The Feluda test is similar to a pregnancy test strip that will just change colour upon detection of the virus and can be used in a simple pathological lab.
    • The Cas9 protein is bar-coded to interact with the SARS-CoV2 sequence in the patient’s genetic material.
    • The Cas9-SARS-CoV2 complex is then put on the paper strip, where using two lines (one control, one test) makes it possible to determine if the test sample was infected.

    Back2Basics: CRISPR technology

    • CRISPR is a short form for Clustered Regularly Interspaced Short Palindromic Repeats.
    • It is a gene-editing technology and finds its use in correcting genetic defects and treating and preventing the spread of diseases.
    • The technology can detect specific sequences of DNA within a gene and uses an enzyme functioning as molecular scissors to snip it.
    • It also allows researchers to easily alter DNA sequences and modify gene function.
    • Moreover, the technology can also be configured for detection of multiple other pathogens in the future.

  • What is Raychaudhuri Equation?

    The Raychaudhuri Equation in General Relativity, derived by Raychaudhuri is in the spotlight after 2020 Physics Nobel was awarded to Penrose for throwing light on Black Holes.

    Try this MCQ:

    Q.The Raychaudhuri Equation is sometimes seen in news is related to:

    Artificial Intelligence/Cloud Computing/Quantum Mechanics/Space Sciences

    What is Raychaudhuri Equation?

    • Raychaudhuri (1923–2005) was an Indian physicist, known for his research in general relativity and cosmology.
    • In general relativity, the Raychaudhuri equation is a fundamental result describing the motion of nearby bits of matter.
    • It was discovered independently by the Indian physicist Amal Kumar Raychaudhuri and the Soviet physicist Lev Landau.
    • The equation offers a simple and general validation of our intuitive expectation that gravitation should be a universal attractive force between any two bits of mass-energy in general relativity, as it is in Newton’s theory of gravitation.

  • Nobel Prize in Chemistry for CRISPR Technology

    French-American duo Emmanuelle Charpentier and Jennifer Doudna have been awarded the 2020 Nobel Prize for the chemistry of CRISPR, which allows scientists to ‘cut-paste’ inside a genetic sequence.

    Try this PYQ:

    Q.What is Cas9 protein that is often mentioned in news?

    (a) A molecular scissors used in targeted gene editing

    (b) A biosensor used in the accurate detection of pathogens in patients

    (c) A gene that makes plants pest-resistant

    (d) A herbicidal substance synthesized in genetically modified crops

    The CRISPR technology

    • The CRISPR is an acronym for Clustered Regularly Interspaced Short Palindromic Repeats, developed in the year 2012
    • CRISPR has made gene editing very easy and simple, and at the same time extremely efficient.
    • The technology works in a simple way — it locates the specific area in the genetic sequence which has been diagnosed to be the cause of the problem, cuts it out, and replaces it with a new and correct sequence that no longer causes the problem.
    • The technology replicates a natural defence mechanism in some bacteria that use a similar method to protect itself from virus attacks.

    Working of CRISPR

    • An RNA molecule is programmed to locate the particular problematic sequence on the DNA strand.
    • A special protein called Cas9, often described in popular literature as ‘genetic scissor’, is used to break and remove the problematic sequence.
    • A DNA strand, when broken, has a natural tendency to repair itself. But the auto-repair mechanism can lead to the re-growth of a problematic sequence.
    • Scientists intervene during this auto-repair process by supplying the desired sequence of genetic codes, which replaces the original sequence.
    • It is like cutting a portion of a long zipper somewhere in between and replacing that portion with a fresh segment.
    • Because the entire process is programmable, it has a remarkable efficiency and has already brought almost miraculous results.

    Uses of CRISPR

    • There are a whole lot of diseases and disorders, including some forms of cancer, that are caused by an undesired genetic mutation.
    • These can all be fixed with this technology. There are vast applications elsewhere as well. Genetic sequences of disease-causing organisms can be altered to make them ineffective.
    • Genes of plants can be edited to make them withstand pests, or improve their tolerance to drought or temperature.

    Ethical concerns

    • In November 2018, a Chinese researcher in Shenzen created an international sensation with his claim that he had altered the genes of a human embryo that eventually resulted in the birth of twin baby girls.
    • This was the first documented case of a ‘designer babies’ being produced using the new gene-editing tools like CRISPR.
    • What made matters worse was that the gene-editing was probably done without any regulatory permission or oversight.

  • What is CBD Oil?

    These days, there are diverse opinions rising regarding the legalization of CBD oil in India after recent controversy rose after the alleged suicide of an actor.

    What is CBD oil?

    • CBD oil is an extract from the cannabis plant.
    • The two main active substances in it are cannabidiol or CBD and delta-9 tetrahydrocannabinol, or THC.
    • The high that is caused by the consumption of cannabis is due to THC.
    • CBD, however, does not cause a “high” or any form of intoxication.
    • CBD oil is made by extracting CBD from the cannabis plant, then diluting it with a carrier oil like coconut or hemp seed oil.

    What are the effects of Cannabidiol?

    • Cannabidiol has effects on the brain, preventing the breakdown of a chemical that aggravates the pain and affects mood, and mental function. It can reduce pain and anxiety.
    • It also reduces psychotic symptoms associated with conditions such as schizophrenia as well as epilepsy.

    Is it legal in India?

    • The Narcotic Drugs and Psychotropic Substances Act, 1985 (NDPS Act) outlaws the recreational use of cannabis.
    • The NDPS Act, however, does not apply to the leaves and seeds of cannabis plants. In case the CBD is extracted from the leaves of the cannabis, then technically it is not illegal.
    • CBD oil manufactured under a licence issued by the Drugs and Cosmetics Act, 1940 can be legally used.
    • However, the use of cannabis as a medicine is not much prevalent in India.

    Now try this PYQ:

    Q. Widespread resistance of malarial parasite to drugs like chloroquine has prompted attempts to develop a malarial vaccine to combat malaria. Why is it difficult to develop an effective malaria vaccine?

    A) Malaria is caused by several species of Plasmodium

    B) Man does not develop immunity to malaria during natural infection

    C) Vaccines can be developed only against bacteria

    D) Man is only an intermediate host and not the definitive host

  • Cat Que Virus

    In a study published in the Indian Journal of Medical Research, scientists have noted the presence of antibodies against the Cat Que virus (CQV) in two human serum samples.

    Try this PYQ:

    Q.Which one of the following statements is not correct?

    (a) Hepatitis B virus is transmitted much like HIV.

    (b) Hepatitis B, unlike Hepatitis C, does not have a vaccine.

    (c) Globally, the number of people infected with Hepatitis B and C viruses is several times more than those infected with HIV.

    (d) Some of those infected with Hepatitis B and C viruses do not show the symptoms for many years.

    What is the Cat Que Virus?

    • For CQV, domestic pigs are considered to be the primary mammalian hosts.
    • Antibodies against the virus indicate that the virus has formed a “natural cycle” in the local area and has the ability to spread in pigs and other animal populations through mosquitoes.
    • CQV belongs to the Simbu serogroup and infects both humans and economically important livestock species.
    • It was first isolated in 2004 from mosquitoes during the surveillance of arbovirus activity in northern Vietnam.
    • In this study, researchers reported a CQV strain (SC0806), which was isolated from mosquito samples collected in China in 2006 and 2008.

    Impact on humans

    • Humans can get infected through mosquitoes as well.
    • In the study, scientists note that because of positivity in human serum samples and the replication capability of CQV in mosquitoes, there is only a “possible disease-causing potential” of CQV in the Indian scenario.

  • [pib] 20 years of Himalayan Chandra Telescope (HCT)

    In the cold, dry desert of Ladakh, 4500 meters above the mean sea level, for two decades, the 2-m diameter optical-infrared Himalayan Chandra Telescope (HCT) at the Indian Astronomical Observatory (IAO) has been scanning the night sky for 20 years in search of stellar explosions, comets, asteroids, and exo-planets.

    Chandra X-Ray observatory and now, it is Himalayan Chandra Telescope. Do you the key difference? The former is a NASA project while the HCT is the Indian one.

    Himalayan Chandra Telescope

    • The HCT is a 2.01 meters (6.5 feet) diameter optical-infrared telescope named after India-born Nobel laureate Subrahmanyam Chandrasekhar.
    • It contains a modified Ritchey-Chretien system with a primary mirror made of ULE ceramic which is designed to withstand low temperatures it experiences.
    • The telescope was manufactured by Electo-Optical System Technologies Inc. at Tucson, Arizona, USA.
    • It is mounted with 3 science instruments called Himalaya Faint Object Spectrograph (HFOSC), the near-IR imager and the optical CCD imager.
    • It is remotely operated from Hosakote, about 35 km northeast of Bangalore via an INSAT-3B satellite link which allows operation even in sub-zero temperatures in winter.

    Significant feats

    • The telescope has been used in many coordinated international campaigns to monitor stellar explosions, comets, and exo-planets, and has contributed significantly to these studies.
    • Some of the thrust research areas are the study of solar system bodies like; comets, asteroids, the study of star formation processes and young stellar objects, the study of open and globular clusters and variable stars in them.
    • It has helped in analysis of elements in the atmosphere of evolved stars, star formation in external galaxies, Active Galactic Nuclei, stellar explosions like novae, supernovae, gamma-ray bursts and so on.

  • Ocean Services, Modelling, Applications, Resources and Technology (O-SMART) SCHEME

    The Union Ministry of Earth Sciences has informed about the progress of O-SMART Scheme.

    Do you know?

    India’s ambitious Deep Ocean Mission is an umbrella scheme under O-SMART initiative. Bottom of Form

    O-SMART Scheme

    • The services rendered under the O-SMART will provide economic benefits to a number of user communities in the coastal and ocean sectors, namely, fisheries, offshore industry, coastal states, Defence, Shipping, Ports etc.
    • It seeks to address issues relating to SDG-14, which aims to conserve the use of oceans, marine resources for sustainable development.
    • It also provides the necessary scientific and technological background required for the implementation of various aspects of Blue Economy.
    • The State of Art Early Warning Systems established Scheme will help in effectively dealing with ocean disasters like Tsunami, storm surges.
    • The technologies being developed will help in harnessing the vast ocean resources of both living and non-living resources from the seas around India.
    • A fleet of research vessels viz., Technology Demonstration vessel SagarNidhi, Oceanographic Research Vessel SagarKanya, Fisheries and Oceanographic Research Vessel SagarSampada and Coastal Research Vessel SagarPurvi have been acquired to provide required research support.

    Some of the modified objective

    The objectives of O-SMART are:

    • To generate and regularly update information on Marine Living Resources and their relationship with the physical environment in the Indian Exclusive Economic Zone (EEZ),
    • To periodically monitor levels of seawater pollutants for health assessment of coastal waters of India, to develop shoreline change maps for assessment of coastal erosion due to natural and anthropogenic activities,
    • To develop a wide range of state-of-the-art ocean observation systems for the acquisition of real-time data from the seas around India,
    • To generate and disseminate a suite of user-oriented ocean information, advisories, warnings, data and data products for the benefit of society,
    • To develop high-resolution models for ocean forecast and reanalysis system,
    • To develop algorithms for validation of satellite data for coastal research and to monitor changes in the coastal research,
    • Acquisition of 2 Coastal Research Vessels (CRVs) as replacement of 2 old CRVs for coastal pollution monitoring, testing of various underwater components and technology demonstration,
    • To carry out exploration of Polymetallic Nodules (MPN) from a water depth of 5500 m in the site of 75000 sq.km allotted to India by United Nations in Central Indian Ocean Basin, to carry out investigations of gas hydrates,
    • Exploration of polymetallic sulphides near Rodrigues Triple junction in 10000 sq. km of the area allotted to India in International waters by International Seabed Authority/UN and,
    • Submission of India’s claim over continental shelf extending beyond the Exclusive Economic Zone supported by scientific data, and Topographic survey of EEZ of India.

    Also read:

    https://www.civilsdaily.com/news/explained-indias-deep-ocean-mission/

  • Hypersonic Technology Demonstrator Vehicle (HSTDV)

    The DRDO has successfully demonstrated the hypersonic air-breathing scramjet technology with the flight test of the Hypersonic Technology Demonstration Vehicle (HSTDV).

    Take note of close dissimilarities between Ramjet and Scramjet engines.

    About HSTDV

    • HSTDV is an unmanned scramjet vehicle with a capability to travel at six times the speed of sound.
    • The scramjets are a variant of a category of jet engines called the air-breathing engines.
    • The ability of engines to handle airflows of speeds in multiples of the speed of sound gives it a capability of operating at those speeds.
    • Hypersonic speeds are those which are five times or more than the speed of sound.
    • The unit tested by the DRDO can achieve upto six times the speed of sound or Mach 6, which is well over 7000 km per hour or around two km per second.

    Its development

    • The DRDO started on the development of the engine in the early 2010s.
    • The ISRO has also worked on the development of the technology and has successfully tested a system in 2016. DRDO too has conducted a test of this system in June 2019.
    • The special project of the DRDO consisted of contributions from its multiple facilities including the Pune headquartered Armament and Combat Engineering Cluster.

    Back2Basics: Ramjet V. Scramjet

    • A ramjet is a form of air-breathing jet engine that uses the vehicle’s forward motion to compress incoming air for combustion without a rotating compressor.
    • Fuel is injected in the combustion chamber where it mixes with the hot compressed air and ignites.
    • A ramjet-powered vehicle requires an assisted take-off like a rocket assist to accelerate it to a speed where it begins to produce thrust.
    • Ramjets work most efficiently at supersonic speeds around Mach 3 (three times the speed of sound) and can operate up to speeds of Mach 6.
    • However, the ramjet efficiency starts to drop when the vehicle reaches hypersonic speeds.
    • A scramjet engine is an improvement over the ramjet engine as it efficiently operates at hypersonic speeds and allows supersonic combustion. Thus it is known as Supersonic Combustion Ramjet or Scramjet.

  • Vitamin-D Deficiency

    The pandemic-induced lockdown has confined people to their houses for five months now. The resultant lack of sunlight, followed by rains, has brought down the vitamin D levels to the lowest.

    Try this PYQ from CSP 2014:

    Q.Consider the following pairs:

    Vitamin Deficiency:: Disease

    1. Vitamin C::Scurvy
    2. Vitamin D:: Rickets
    3. Vitamin E:: Night blindness

    Which of the pairs given above is/are correctly matched?

    (a) 1 and 2 only

    (b) 3 only

    (c) 1, 2 and 3

    (d) None

    What is Vitamin-D?

    • Vitamin D is an essential vitamin that has myriad positive effects on several systems in the body.
    • Unlike other vitamins, it functions like a hormone and every cell in your body has a receptor for it.
    • It is sparsely found in certain fatty fish and fortified dairy products, and it is extremely difficult to get the Recommended Daily Intake (RDI) of 600-800 IU from diet alone.

    There are two main forms of vitamin D in the diet:

    – Vitamin D2 (Ergocalciferol) — found in plant foods like mushrooms.
    – Vitamin D3 (Cholecalciferol) — found in animal foods like salmon, cod and egg yolks.

    Common signs and symptoms of the deficiency

    Vitamin D deficiency is incredibly common and most people are unaware of it, as the symptoms are subtle and nonspecific.

    – Getting sick or infected often with common cold and flu, because of a weak immune system.
    – Fatigue and tiredness
    – Bone and muscle pains
    – Depression
    – Impaired wound healing
    – Bone loss and osteoporosis

    Sources of Vit. D

    • Sunlight is the best natural source of vitamin D. Sunlight synthesizes cholesterol into Vitamin D3.
    • Usually, 20 to 30 minutes of sun exposure between 10 am and 3 pm is adequate to meet daily requirements, in places with minimum pollution levels.

  • What is Carbon-14 (C14) Battery?

    A California-based company has made a self-charging battery, which can run for 28,000 years on a single charge, by trapping carbon-14 (C14) nuclear waste in artificial diamond-case.

    Try this PYQ:

    Q.The known forces of nature can be divided into four classes, viz. gravity, electromagnetism, weak nuclear force and strong nuclear force. With reference to them, which one of the following statements is not correct?

    (a) Gravity is the strongest of the four

    (b) Electromagnetism act only on particles with an electric charge

    (c) Weak nuclear force causes radioactivity

    (d) Strong nuclear force holds protons and neutrons inside the nuclear of an atom.

    What is C14?

    • Carbon-14 (14C), or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.
    • There are three naturally occurring isotopes of carbon on Earth: carbon-12, which makes up 99% of all carbon on Earth; carbon-13, which makes up 1%; and carbon-14, which occurs in trace amounts.
    • Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples.

    C14 battery

    • The battery works by generating electricity on its own from a shower of electrons as a result of radioactive decay scattered and deposited in the artificial diamond-case.
    • The battery can be used in electric vehicles, mobile phones, laptops, tablets, drones, watches, cameras, health monitors and even sensors.
    • It is also said to be extremely safe and tamper-proof as it is coated with a non-radioactive diamond which prevents radiation leaks.

    Best example of nuke waste recycling

    • It is estimated that 33 million cubic metres of global nuclear waste will cost over $100 billion to manage and dispose of.
    • And a lot of this waste is graphite that is one of the higher risks of radioactive waste and one of the most expensive and problematic waste to store.

    Its applications

    • The company says its battery can be used to powerhouses, and that any excess electricity generated can be sold to the grid.
    • As the new battery need not be replaced, it can be installed in hard to reach places like pacemakers and implants, where a regular change of battery is not possible.
    • Another area of use is space electronics. The battery is said to power space equipment in rockets.
    • It can power the electrical needs of space crafts, like providing power to cockpits and assisting launch into the upper atmosphere.