💥Mains Ready By December. Smash Mains & Smash PYQ Admissions Open
Talk to Mentor

Civilsdaily

Login

Subject: Basic Sciences

  • Vitamin D and its health benefits

    There have been considerable discussions in scientific circles on the importance of vitamin D in these days of the COVID-19 pandemic.

    Try this question from CSP 2017:

    Q.Regular intake of fresh fruits and vegetables is recommended in the diet since they are a good source of antioxidants. How do antioxidants help a person maintain health and promote longevity?

    (a) They activate the enzymes necessary for vitamin synthesis in the body and help prevent vitamin deficiency.

    (b) They prevent excessive oxidation of carbohydrates, fats and proteins in the body and help avoid unnecessary wastage of energy.

    (c) They neutralize the free radicals produced in the body during metabolism.

    (d) They activate certain genes in the cells of the body and help delay the ageing process.

    Vitamin D and its prevalence

    • It is produced when sunlight (or artificial light, particularly in the ultraviolet region of 190-400 nm wavelength) falls on the skin.
    • Light triggers a chemical reaction to a cholesterol-based molecule and converts it into calcidiol in the liver and into calcitriol in the kidney.
    • It is these two molecules that are physiologically active.
    • Since sunlight is important for the generation of vitamin D, tropical countries have an advantage over the northern countries.
    • India, being a tropical country, one would expect naturally derived vitamin D levels to be good.

    Why Vitamin D is important?

    • Vitamin D deficiency can affect COVID-19 high-risk patients, particularly those who are diabetic, have heart conditions, pneumonia, obesity and those who smoke.
    • It is also associated with infections in the respiratory tract and lung injury.
    • Besides, vitamin D is known to help in having the right amount of calcium in the bones, catalyse the process of protecting cell membranes from damage, preventing the inflammation of tissues.
    • Moreover, it helps stop tissues from forming fibres and weakening bones from becoming brittle, leading to osteoporosis.

  • Trending in news: 5G Technology

    One of India’s business tycoon recently announced that his company’s telecom venture has designed and developed from scratch, a complete indigenous 5G solution ready for deployment.

    Try this question from CSP 2019:

    Q.With reference to communication technologies, what is/are the difference/differences between LTE (Long-Term Evolution) and VoLTE (Voice over Long-Term Evolution)?

    1. LTE ‘is commonly marketed as 3G and VoLTE is commonly marketed as advanced 3G.
    2. LTE is data-only technology and VoLTE is voice-only technology.

    Select the correct answer using the code given below.

    (a) 1 only

    (b) 2 only

    (c) Both 1 and 2

    (d) Neither 1 nor 2

    What is 5G?

    • 5G or fifth generation is the latest upgrade in the long term evolution (LTE) mobile broadband networks.
    • The first generation of networks allowed only mobile voice calls to be made, while the second generation allowed mobile voice calls as well as sending of short text messages.
    • It was the third generation or 3G network which allowed web browsing on mobile devices, the speed and latency of which improved with fourth-generation or 4G networks.
    • The 5G networks will have even faster speeds with latency down to between 1-10 milliseconds.

    (Note: Latency is the time a device takes to communicate with the network, which stands at an average of up to 50 milliseconds for 4G networks across the world.)

    How does 5G work?

    All 5G networks chiefly operate on three spectrum bands.

    • The low-band spectrum has been proven to have great coverage and works fast even in underground conditions. However, the maximum speed limit on this band is 100 Mbps (Megabits per second).
    • In the mid-band spectrum, though the speeds are higher, telcos across the world have registered limitations when it comes to coverage area and penetration of telephone signals into buildings.
    • The high-band spectrum offers the highest speed but has extremely limited network coverage area and penetration capabilities.

    The telcos using this band rely on the existing LTE networks and will need to install a number of smaller towers to ensure adequate coverage and high-speed performance.

    What does it mean to be 5G ready?

    • Globally many companies have been deploying 5G networks across their service areas as early as 2018.
    • Not only the network, but the devices will also have to be 5G ready for customers to be able to enjoy the maximum benefits of the latest upgrade in mobile broadband.
    • One of the major improvements in 5G is the use of beam tracking to follow all devices on the network to ensure consistent connection in real-time for the device.
    • 5G networks are also designed to multiple-input multiple-output (MIMO) efficient which improves signal throughput for all devices on the network.

    Where does India stand on the deployment of 5G?

    • Companies, both telecom service providers and their equipment vendors, have completed lab trials of 5G network components but are yet to commence field trials, which were initially scheduled to happen last year.
    • For the same, telecom companies are awaiting allocation of test spectrum from the Department of Telecommunications (DoT).
    • The service providers have already tied up with equipment makers like Nokia, Ericsson, etc for deploying their 5G networks.

  • What is T Cells Immunity?

    A recent study has shown that people unexposed to and not infected with novel coronavirus may still exhibit T cell responses specific to this virus. It is thought that Coronavirus specific T cell responses seen in healthy people might arise from memory T cells derived from exposure to ‘common cold’ coronaviruses.

    Try this question from CSP 2010:

    Q. Widespread resistance of malaria parasite to drugs like chloroquine has prompted attempts to develop a malaria 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

    What are T Cells?

    • T Cells also called T lymphocyte, type of leukocyte (white blood cell) that is an essential part of the immune system.
    • T cells are one of two primary types of lymphocytes—B cells being the second type—that determine the specificity of the immune response to antigens (foreign substances) in the body.
    • T cells originate in the bone marrow and mature in the thymus.

    Why are they called memory cells?

    • In the thymus, T cells multiply and differentiate into helper, regulatory, or cytotoxic T cells or become memory T cells.
    • They are then sent to peripheral tissues or circulate in the blood or lymphatic system.
    • Once stimulated by the appropriate antigen, helper T cells secrete chemical messengers called cytokines, which stimulate the differentiation of B cells into plasma cells (antibody-producing cells).

    How do they control immunity?

    • Regulatory T cells act to control immune reactions, hence their name.
    • Cytotoxic T cells, which are activated by various cytokines, bind to and kill infected cells and cancer cells.
    • Because the body contains millions of T and B cells, many of which carry unique receptors, it can respond to virtually any antigen.

    Vaccination outcomes on T cells

    • There is a possibility that pre-existing T cell memory might influence vaccination outcomes.
    • Pre-existing immunity could help elicit better immune responses against novel coronavirus, and these responses can manifest faster.
    • Meanwhile, pre-existing immunity could be mistaken as an enhanced efficacy of the vaccine in eliciting immune responses.
    • This could be particularly confusing in Phase-1 trials where the vaccine is tested on a small group of healthy participants.

    Its drawbacks

    • The pre-existing immunity can reduce the immune responses that the vaccine causes through a mechanism called the “original antigenic sin”.
    • It can also lead to antibody-mediated disease enhancement, where antibodies present at sub-neutralizing concentrations can actually augment virus infection and cause more severe disease.
    • This was seen in the case of chikungunya and dengue.

  • Explaining Lithium increase in the Universe

    In a study recently published in Nature Astronomy scientists from Indian Institute of Astrophysics (IIA) along with their international collaborators have provided a robust observational evidence for the first time that Li production is common among low mass Sun-like stars during their He-core burning phase.

    Importance of lithium in our life

    • Light inflammable, metal lithium (Li) has brought about transformation in modern communication devices and transportation.
    • A great deal of today’s technology is powered by lithium in its various shades [remember Li-ion battery!].
    • But where does the element come from?
    • The origin of much of the Li can be traced to a single event, the Big-Bang that happened about 13.7 Billion years ago, from which the present-day Universe was also born.

    Why lithium was thought to be different?

    • Li content in the physical Universe has increased by about a factor of four over the life of the Universe.
    • However, the rest of the elements carbon, nitrogen, oxygen, iron, nickel and so on which grew about a million times over the lifetime of the Universe.
    • Li, however, understood to be an exemption!
    • Current understanding is that lithium in stars like our Sun only gets destroyed over their lifetime.
    • As a matter of fact, the composition of all the elements in the Sun and the Earth is similar.
    • But, the measured content of Li in the Sun is a factor of 100 lower than that of the Earth, though both are known to have formed together.

    So, what the new finding suggests?

    • This discovery challenges the long-held idea that stars only destroy lithium during their lifetime.
    • It implies that the Sun itself will manufacture lithium in the future.
    • This is not predicted by models, indicating that there is some physical process missing in stellar theory.
    • Further, the authors identified “He flash”.
    • “He flash” is an on-set of He-ignition at the star’s core via violent eruption at the end of the star’s core hydrogen-burning phase, as the source of Li production.
    • Our Sun will reach this phase in about 6-7 billion years.

  • What is Raman Spectroscopy?

    Mumbai-based researchers have turned to Raman Spectroscopy to detect RNA viruses present in saliva samples.

    Try this question from CSP 2017
    Q.Which Indian astrophysicist and Nobel laureate predicted rapidly rotating stars emit polarized light?
    (a) Subrahmanyan Chandrasekhar
    (b) CV Raman
    (c) Ramanujan
    (d) Amartya Sen

    The Raman Spectroscopy

    • Raman spectroscopy is an analytical technique where scattered light is used to measure the vibrational energy modes of a sample.
    • In 1928, Raman discovered that when a stream of light passes through a liquid, a fraction of the light scattered by the liquid is of a different colour.
    • While Raman was returning from London in a 15-day voyage, he started thinking about the colour of the deep blue Mediterranean.
    • He wasn’t convinced by the explanation that the colour of the sea was blue due to the reflection of the sky.
    • As the ship docked in Bombay, he sent a letter to the editor of the journal Nature, in which he penned down his thoughts on this.
      Subsequently, Raman was able to show that the blue colour of the water was due to the scattering of the sunlight by water molecules.
    • By this time he was obsessed with the phenomenon of light scattering.

    How does it work?

    • The Raman Effect is when the change in the energy of the light is affected by the vibrations of the molecule or material under observation, leading to a change in its wavelength.
    • Significantly, it notes that the Raman effect is “very weak” — this is because when the object in question is small (smaller than a few nanometres), the light will pass through it undisturbed.
    • But a few times in a billion, light waves may interact with the particle. This could also explain why it was not discovered before.
    • In general, when light interacts with an object, it can either be reflected, refracted or transmitted.
    • One of the things that scientists look at when light is scattered is if the particle it interacts with is able to change its energy.

    Applications

    • Raman spectroscopy is used in many varied fields – in fact, any application where non-destructive, microscopic, chemical analysis and imaging is required.
    • Whether the goal is qualitative or quantitative data, Raman analysis can provide key information easily and quickly.
    • It can be used to rapidly characterize the chemical composition and structure of a sample, whether solid, liquid, gas, gel, slurry or powder.

  • Phobos: The closest and biggest moon of Mars

    The Mars Colour Camera (MCC) onboard ISRO’s Mars Orbiter Mission (MOM) has captured the image of Phobos, the closest and biggest moon of Mars.

    Try this question from CSP 2017:

    Q.Which region of Mars has a densely packed river deposit indicating this planet had water 3.5 billion years ago?

    (a) Aeolis Dorsa (b) Tharsis (c) Olympus Mons (d) Hellas

    About Phobos

    • Phobos is the innermost and larger of the two natural satellites of Mars, the other being Deimos.
    • Both moons were discovered in 1877 by American astronomer Asaph Hall.
    • Phobos is a small, irregularly shaped object with a mean radius of 11 km and is seven times as massive as the outer moon, Deimos.
    • Phobos is largely believed to be made up of carbonaceous chondrites.
    • The violent phase that Phobos has encountered is seen in the large section gouged out from a past collision (Stickney crater) and bouncing ejecta.

    Back2Basics: Mars Orbiter Mission (MOM)

    • The MOM also called Mangalyaan is a space probe orbiting Mars since 24 September 2014. It was launched on 5 November 2013 by the Indian Space Research Organisation (ISRO).
    • It aims at studying the Martian surface and mineral composition as well as scans its atmosphere for methane (an indicator of life on Mars).
    • It is India’s first interplanetary mission and it made it the fourth space agency to reach Mars, after Roscosmos, NASA, and the European Space Agency.
    • It made India the first Asian nation to reach Martian orbit and the first nation in the world to do so on its maiden attempt.
    • It was initially meant to last six months, but subsequently, ISRO had said it had enough fuel for it to last “many years.”

  • ‘Accelerate Vigyan’ Scheme

    To provide a single platform for research internships, capacity building programs and workshops across the country, the Science and Engineering Research Board (SERB) has launched a new scheme called ‘Accelerate Vigyan’ (AV).

    Note the following things about the ‘Accelerate Vigyan’ Scheme:

    1) Implementing agency/ Nodal Ministry

    2) Primary objective

    3) Target beneficiaries

    4) Its components

    ‘Accelerate Vigyan’ Scheme

    • Accelerate Vigyan (AV) strives to provide a big push to high-end scientific research and prepare scientific manpower which can venture into research careers and knowledge-based economy.
    • The primary objective of this scheme is to give more thrust on encouraging high-end scientific research and preparing scientific manpower, which can lead to research careers and knowledge-based economy.
    • AV will initiate and strengthen mechanisms of identifying research potential, mentoring, training and hands-on workshop on a national scale.
    • The aim is to expand the research base in the country, with three broad goals – consolidation / aggregation of all scientific training programs, initiating High-end Orientation Workshops and creating opportunities for Research Internships.

    Components of AV

    1) ABHYAAS

    • It is an attempt to boost research and development in the country by enabling and grooming potential PG/PhD students by means of developing their research skills in selected areas across different disciplines or fields.
    • It has two components: High-End Workshops (‘KARYASHALA’) and Research Internships (‘VRITIKA’).
    • This is especially important for those researchers who have limited opportunities to access such learning capacities/facilities/infrastructure.

    2) SAMOOHAN

    • Mission ‘SAMOOHAN’ marks the beginning of Accelerate Vigyan.
    • It aims to encourage, aggregate and consolidate all scientific interactions in the country under one common roof.
    • It has been sub-divided into ‘SAYONJIKA’ and ‘SANGOSHTI’.
    • SAYONJIKA is an open-ended program to catalogue the capacity building activities in science and technology supported by all government funding agencies in the country.
    • SANGOSHTI is a pre-existing program of SERB.

  • Gold Nanoparticles and their applications

    Indian researchers have successfully synthesized gold nanoparticles (GNPs) using psychrotolerant Antarctic bacteria through a non-toxic, low-cost, and eco-friendly way.

    Nanotechnology is a pathbreaking technology which can create many new materials and devices with a wide range of applications, such as in nanomedicine, nanoelectronics etc.   GNPs are another distinct development.

    What are Gold Nanoparticles?

    • Metallic NPs have been efficiently exploited for biomedical applications and among them, GNPs are found to be effective in biomedical research.
    • And NPs are those materials that are at least one dimension smaller than 100 nanometers.
    • NPs have a high surface-to-volume ratio and they can provide the tremendous driving force for diffusion, especially at elevated temperatures.
    • GNPs are melted at much lower temperatures (300 °C) than bulk gold (1064 °C).
    • NPs have been found to impart various desirable properties to different day-to-day products.
    • For example, GNPs are found to have greater solar radiation absorbing ability than the conventional bulk gold, which makes them a better candidate for use in the photovoltaic cell manufacturing industry.

    Properties of GNP

    1) Biomedical

    • Genotoxicity describes the property of a chemical agent that is capable of damaging the genetic information of DNA and thus causing the mutation of the cell, which can lead to cancer.
    • The study revealed the genotoxic effect of GNPs on a sulphate reducing bacteria (SRB).
    • These GNPs can be used as composite therapeutic agent clinical trials, especially in anti-cancer, anti-viral, anti-diabetic, and cholesterol-lowering drugs.

    2) Optical

    • GNPs have unique optical properties too. For example, particles above 100 nm show blue or violet colour in the water, while the colour becomes wine red in 100 nm gold colloidal particles.
    • They can thus be used for therapeutic imaging.

    3) Electronics

    • GNPs are also found to be useful in the electronics industry.
    • Scientists have constructed a transistor known as NOMFET (Nanoparticles Organic Memory Field-Effect Transistor) by embedding GNPs in a porous manganese oxide.
    • NOMFETs can mimic the feature of the human synapse known as plasticity or the variation of the speed and strength of the signal going from neuron to neuron.
    • These novel transistors can now facilitate better recreation of certain types of human cognitive processes, such as recognition and image processing and have their application in AI.

  • What is Gynandromorphism?

    Recently, a rare biological phenomenon called Gynandromorphism was observed in dragonflies at Kole wetlands of Kerala.

    Gynandromorphism is a core biology concept. We can expect a prelims question in a rare scenario.

    Try this question from CSP 2013:

    Q.Improper handling and storage of cereal grains and oilseeds result in the production of toxins known as aflatoxins which are not generally destroyed by normal cooking process. Aflatoxins are produced by

    (a) Bacteria (b) Protozoa (c) Moulds (d) Viruses

    Gynandromorphism

    • Gynandromorphs are individual animals that have both genetically male and female tissues and often have observable male and female characteristics.
    • They may be bilateral, appearing to divide down the middle into male and female sides, or they may be mosaic, with patches characteristic of one sex appearing in a body part characteristic of the other sex.
    • Gynandromorphs occur in insects, spiders, crustaceans, and other arthropods as well as in birds, but they are extremely rare, and discovering one in the field or in the laboratory is a major event.
    • Estimating how frequently they occur is difficult because they usually go unnoticed in species where sexual dimorphism is less pronounced.
    • Gynandromorphs have been reported in mosquitoes, fruit flies, and in other insects, but they are most dramatic in those butterfly species in which the male and female wing colours and patterns are dramatically different.

  • Statistics Day and P.C. Mahalanobis

    Statistics Day will be celebrated today on 29th June 2020 to popularize the use of Statistics in everyday life and sensitize the public as to how Statistics helps in shaping and framing policies.

    Try this question from CSP 2016:

    A recent movie titled The Man Who Knew Infinity is based on the biography of-

    (a) S. Ramanujan
    (b) S. Chandrasekhar
    (c) S. N. Bose
    (d) C. V. Raman

    Who was P.C. Mahalanobis?

    • Prasanta Chandra Mahalanobis (29 June 1893 – 28 June 1972) was an Indian scientist and statistician.
    • He is best remembered for the Mahalanobis distance, a statistical measure, and for being one of the members of the first Planning Commission of free India.
    • He made pioneering studies in anthropometry (the science of obtaining systematic measurements of the human body) in India.
    • He founded the Indian Statistical Institute and contributed to the design of large-scale sample surveys.
    • For his contributions, Mahalanobis has been considered the father of modern statistics in India.