SnT - Last 18 months Current Affairs Part - I

By Dr. Roman Saini

1. Basic Science

Hydrogen Fuel cell train● Germany launched the world’s first hydrogen fuel cell powered trains

called Coradia iLint. It can reach speeds of up to 140 km per hour.

● It is manufactured by the French Company, Alstom

● Hydrogen trains are equipped with fuel cells that produce electricity through a combination of hydrogen and oxygen, a process that leaves steam and water as the only emissions.

● Excess energy is stored in ion lithium batteries on board the train.

● The Coradia iLint trains can run for about 600 miles (1,000km) on a single tank of hydrogen, similar to the range of diesel trains.

Benefits

● It a greener alternative to diesel for non-electrified railway lines.

● It has low levels of noise

● It is an efficient means to combat air pollution.

● It is cheaper to run the train

● It has high levels of performance

Disadvantages

● It is expensive

Micro-LED

● It was launched for the consumers for the first time by Samsung through Samsung 146-inch MicroLED TV, which the company called “The Wall.”

● LED TVs – Light Emitting Diode TVs

● They contain many Liquid Crystal Display panels with a bunch of LED lights behind them.

● A LCD panel does not have its own light and hence LEDs are used to provide light in an LED TV.

Organic LED TV (OLED)

● It uses emissive display technology.

● Each pixel in an OLED has its own light.

● Hence OLED TVs have deep contrast ratios and better per-pixel accuracy in the picture than any other display type on the market.

● It also has perfect black levels, excellent color, and near-perfect off-angle viewing.

Disadvantage – They are made with organic compounds. Hence, OLEDs are expensive, have limited brightness and can potentially suffer burn-in (discolouration/image retention).

Micro-LED

● It is also an emissive display. But it does not use organic compounds to make light.

● They not only offer perfect blacks, excellent color, and near-perfect off-angle viewing, like OLEDs but also are even brighter, very slim, immune to burn-in.

● It also has lower power consumption and longer life-span.

Artificial Moon

● It is a kind of large mirror that is being developed by China.

● It is intended to provide street lighting over one of the towns of China, Chengdu.

● A mirror will orbit Chengdu at a height of 500km which will reflect the Sun’s light at night to provide for street lighting.

● If found to be successful, more such moons would be launched by 2022.

Benefits

● It is estimated to have a brightness of around eight times that of the moon.

● The brightness would be a fifth of a streetlight’s.

● The moon would illuminate an area of diameter between 10-80 km.

● It will save electricity costs for China.

● It would prove useful during in disaster prone areas where streetlights would not function during disasters.

Challenges

● Accuracy of lighting is an important challenge considering the height and the diameter of lighting. The angle of reflection would play an important role in accuracy.

● There should be sufficient lighting to act as streetlight.

● It could affect the daily cycle of animals and plants and human circadian system- biological clock of humans.

● China is not the first country to deploy large mirror. Russia has launched such large mirrors but with negative results.

SI units● The International System of Units or SI is the modern form of the metric

system, and is the most widely used system of measurement.● SI units arose during the Eleventh General Conference of Weights and

Measures (CGPM) conducted by the International Bureau of Weights and Measures (BIPM) in Paris in 1960.

● The SI model has four major components.

○ Seven defining constants with exact values○ Seven dimensionally independent, base units○ A large number of derived units○ Prefixes

● Defining constants are universal constants which include Plancks constant h, Boltzmann constant k, speed of light c etc.

● Base units comprise seven basic units of measurement, namely,

○ Ampere for measurement of electric current

○ Kelvin for measurement of temperature

○ Second for measurement of time

○ Metre for measurement of length

○ Kilogram for measurement of weight

○ Candela for measurement of luminescence

○ Mole for measurement of amount of substance

● The base units are derived from invariant constants of nature, such as the speed of light in vacuum which can be observed and measured with great accuracy, and one physical artefact.

● Derived units comprise units such as lumen and watt used for other common physical quantities.

● Prefixes are added to unit names to produce multiples and sub-multiples of the original unit.

● For example, kilo- denotes a multiple of a thousand.

26th CGPM

● The 26th CGPM resulted in an overhaul of definitions of base units.

● Base units are defines in terms of physical artefacts.

● For instance, for kilogram, the physical artefact used is a cylinder of platinum-iridium which is kept at BIPM in Paris, which nominally has the same mass as one litre of water at freezing point.

● It is made of 90% platinum and 10% iridium.

● This object has served science and technology well for nearly 130 years, but its stability during this period could only be confirmed by comparisons with identical copies, which is a difficult process and potentially inaccurate.

New definitions of SI units

● The 26th CGPM voted to define SI units in terms of constants that describe the natural world.

● The new definitions will be implemented from May 2019 onwards. These include

● The kilogram – will be defined by the Planck constant (h)

● The ampere – will be defined by the elementary electrical charge (e)

● The kelvin – will be defined by the Boltzmann constant (k)

● The mole – will be defined by the Avogadro constant (NA)

Significance

● The size of the units will not change and will remain the same.

● The redefinition based on fundamental constants of nature will ensure a more stable basis for the accurate and safe measurement of quantities of food ingredients or contaminants.

● It will provide universal access to the SI base units.

● The new changes will have wide-reaching impact in science, technology, trade, health and the environment, among many other sectors.

Rydberg Polarons

● It is a new state of matter created by scientists in 2018

● Scientists have successfully created a “giant atom” and filled it with ordinary atoms, creating a new state of matter termed “Rydberg polarons”.

● These atoms are held together by a weak bond and is created at very cold temperatures.

● Two special fields of atomic physics, which can only be studied in extreme conditions, have been combined in this research project: Bose-Einstein condensates and Rydberg atoms.

● A Bose-Einstein condensate is a state of matter created by atoms at ultracold temperatures, close to absolute zero.

● Rydberg atoms are those in which one single electron is lifted into a highly excited state and orbits the nucleus at a very large distance.

How was it created?

● Scientists used strontium atoms to create a Bose-Einstein condensate.

● Then, it was converted into a Rydberg atom by transferring energy using laser. The resultant Rydberg atom has a huge atomic radius.

● So, the radius of the orbit in which the electron moves around the nucleus is much larger than the typical distance between two atoms in the condensate.

● Therefore, the electron orbits its own atomic nucleus, while numerous other atoms lie inside its orbit, too.

● Thus many Strontium atoms may be enclosed by the same electronic orbit.

● Though negligible the atoms influence the electron in the orbit scattering it but without making the electron leave its orbit.

● This kind of interaction can be observed only at very low temperatures as the bond would break if the electron moves faster.

● This new state of matter is called Rydberg Polaron.

● Use – study cosmology. Some theories say that the mysterious dark matter that exerts force on other matter could be a BEC.

Interstitium

● Scientists discovered the new organ, Interstitium, which consists of fluid-filled spaces, in the body's connective tissue, including in the skin's dermis.

● These fluid-filled spaces were discovered in connective tissues all over the body, including below the skin's surface; lining the digestive tract, lungs and urinary systems; and surrounding muscles.

● As they never showed up on standard microscopic slides, they were missed by eminent scientists.

● Also, the slide making process which involved treating the samples with chemicals, cutting them and dying them to highlight key features made interstitium to collapse.

● Scientists were already aware of the presence of fluid between individual cells, but, the idea of a larger, connected interstitium — in which there are fluid-filled spaces within tissues is new.

● A new technology called a "probe-based confocal laser endomicroscopy" or pCLE was used to view the interstitium. This tool combines an endoscope with a laser and sensors that analyze reflected fluorescent patterns and gives researchers a microscopic view of living tissues.

● The finding has not been officially designated as it requires more consent after further study.

Enhancing optoelectronic properties

● Recently, researchers have found a way to enhance the opto electronic properties of tungsten diselenide.

● Opto-electronics is a combination of optics and electronics.

● Optoelectronics concerns the study and application of light-emitting or light-detecting devices.

● Materials such as tungsten diselenide (WSe2) and molybdenum diselenide exhibit photoluminescence, in which the material absorbs light and re-emits it as a spectrum.

● Photoluminescence properties can be used in various devices such as quantum LEDs which can be used in communication and computation.

● Opto-electronic devices include those that emit light (LEDs and light bulbs), channel light (fiber optic cables), detect light (photodiodes and photoresistors), or are controlled by light (optoisolators and phototransistors).

Cloud Seeding● Cloud seeding is an artificial way of inducing moisture into the clouds

to make it rain.

● Cloud seeding makes use of the natural process of rainfall.

● Water molecules, at extremely low temperatures in the air, accumulate around naturally occuring particles in the air like dust to form ice.

● Such ice crystals grow further until the clouds become heavy to support them which then falls down as rain.

● Cloud seeding is a technique which speeds up this process by providing the particles around which the water particles can condense around.

● In cloud seeding, silver iodide, potassium iodide or silver chloride is sprayed into the atmosphere to act as the hygroscopic nuclei.

● It is used by more than 50 countries to alter the weather.

Benefits

● It can be used to control the weather.

● It can make regions like the deserts more hospitable.

● It can lead to economic development of the country given the fact that more than 60% of the population is dependent on agriculture which is mostly dependent on rains.

● As the technique can be used not only for creating artificial rains but also prevent rains, it can be used to control disasters like floods and other undesirable forms of rains like hail stones.

Concerns

● Though cloud seeding has been used by many countries, its effects, particularly in the long term, are not fully known.

● It may change the climatic patterns that exist in the world today, the effects of which may not be fully predictive.

● It is not known how the chemicals sprayed into the air would affect the plants, animals and birds.

● It is an expensive method.

Way forward

● Since the long term effects of cloud seeding are not fully known, the method should be used sparingly.

● Other natural methods of combating climate change should be tried like afforestation etc.

● Water intensive crops should be avoided in areas where rainwater is not abundantly available.

● Harvesting rainwater for later use and using water judiciously can go a long way in conservation of water.

2. Health and Diseases

Ban on antibiotics

● The manufacture, sale and distribution of the antibiotic colistin has been banned by the Health Ministry.

● Colistin is an antibiotic which is used in food-producing animals, poultry, aqua farming and animal feed supplements in India to boost the weight of poultry and to fight infections in animals.

● Colistin is the last resort drug against multidrug resistant gram-negative infections such as pneumonia and bacteremia in critically ill patients in intensive care units.

● Colistin has been banned under the under provisions of the Drugs and Cosmetics Act, 1940.

● The ban was recommended by India’s top drug advisory body, the Drugs Technical Advisory Board and the National Antimicrobial Resistance Action Plan committee.

● The manufacturer of the drug and its formulations have been asked by the ministry to label the packaged drug and mention clearly the words: Not to be used in food-producing animals, poultry, aqua farming and animal feed supplements.

● The indiscriminate use of colistin had resulted in patients showing resistance to the drug.

● India joins China, the EU, the United States and Brazil in banning the use of Colistin.

● The World Health Organization (WHO) recently released AWaRe, an online tool aimed to ensure safer antibiotic use and reduce antimicrobial resistance (AMR), a global public health threat.

● As part of this, colistin has been marked ‘Reserved’, meaning it should only be used as a last resort when all other antibiotics have failed.

● Apparently, colistin is also listed as a highest priority critically important antibiotic (HPCIA) in the WHO’s list of critically important antimicrobials for human medicine. But it is allowed to be used for non-therapeutic purposes in animals which includes its use for growth promotion as well as for preventing diseases in healthy animals.

National Action Plan on Antimicrobial Resistance(NAP-AMR) 2017 – 2021

● Indian National Action Plan on AMR aims to restrict and phase out non-therapeutic use of antimicrobials such as their use as growth promoters and disease prevention in animals.

● In May 2015, the sixty-eighth World Health Assembly endorsed the Global Action Plan on Antimicrobial Resistance (GAP-AMR) – including antibiotic resistance, the most urgent drug resistance trend.

● In addition to the 5 priorities of GAP-AMR, India added a sixth priority.

Six strategic priorities are

1. improving awareness and understanding of AMR through effective communication, education and training

2. strengthening knowledge and evidence through surveillance

3. reducing the incidence of infection through effective infection prevention and control

4. optimizing the use of antimicrobial agents in health, animals and food

5. promoting investments for AMR activities, research and innovations

6. strengthening India’s leadership on AMR

E-cigarettes

● An electronic cigarette or e-cigarette creates the feeling of tobacco smoking.

● It works by heating a liquid to generate an aerosol, commonly called a "vapor", that the user inhales.

● Using e-cigarettes is sometimes called vaping.

● It does not use tar as is used in normal cigarettes.

● It uses e-liquid which consists of nicotine, propylene glycol, glycerine, and flavorings.

Concerns:

● Adolescents are getting attracted towards e-cigarettes.

● Their efficacy as a replacement of tobacco smoking is still unproven.

● The use of formaldehyde and nicotine can adversely affect the health of users.

● In India, e-cigarettes do not come under Cigarettes and other Tobacco Products Act 2003 which prohibits all forms of advertisements (both direct and indirect) of tobacco products.

● Therefore its promotion and use should be regulated and restricted.

West Nile Virus

● It was recently detected in Kerala.

● It is most commonly spread to people by the bite of an infected mosquito.

● Birds are the natural hosts of West Nile virus.

● There are no vaccines to prevent or medications to treat WNV in people.

● Most people infected with WNV do not feel sick. About 1 in 5 people who are infected develop a fever and other symptoms.

India Trans Fat Free by 2020

● Trans fats are unsaturated fatty acids having at least one unsaturated, non-conjugated double bond in the trans configuration.

● Consumption of trans fats are associated with an increased risk of cardiovascular disease.

● They naturally occur through anaerobic fermentation in the gut of ruminant animals.

● Industrially produced trans fats are formed by modification of unsaturated fat during industrial processing methods, mainly through partial hydrogenation in the presence of a metal catalyst and high heat.

● Partial hydrogenation is the key mechanism where oil is hardened for commercial purposes to change its texture, prevent rancidity and tolerance to repeated high temperatures.

● The proportion of industrially produced trans fats in diets are usually much greater than ruminant trans fat.

● The FAO WHO Population Nutrient Intake Goals provide the following recommendations regarding trans and saturated.

○ Energy from trans fat should be less than 1% of total energy.

○ Energy from saturated fat should be less than 10% of total energy

● The World Health Organisation has warned the governments across the world to eliminate the use of trans fats from global food supplies by 2023 as the NCDs are showing unresistable growth.

● Accordingly, India has proposed to limit the maximum amount of trans fat content in vegetable oils, vegetable fat and hydrogenated vegetable oil to 2 per cent to make India trans fat-free by 2022.

● However, at present, the permitted level of trans fat in food products is 5 per cent in India.

● The Food Safety and Standards Authority of India (FSSAI) has also implemented mandatory labeling of trans fats and saturated fats on vanaspati packs, edible oils and food products containing vanaspati.

Moscow Declaration- Ending TB by 2035

● WHO End TB Strategy was implemented in the year of 2016 in the context of the United Nations Sustainable Development Goals Agenda 3 target to end the epidemic by 2030.

● The Moscow declaration were held in November 2017. It emphasized the need for fixing multisectoral responsibility towards ending TB by 2035 that is the global target.

● India is among the signatories to the declaration.

● The Declaration spells out the commitments from Member States and calls for action at global and regional levels on the part of WHO and a wide range of partners.

● The PM has set to eradicate TB from India five years ahead, by 2025.

UN High-level Meeting on TB

● The first ever UN High-level Meeting on TB was held in September 2018 in New York to review the report card of Moscow declaration.

● The United Nations (UN) General Assembly have committed to ensure that 40 million people with tuberculosis (TB) receive the care they need by end 2022.

● At the meeting, it was agreed to mobilize US$ 13 billion a year by 2022 to implement TB prevention and care, and US$ 2 billion for research by the world leaders.

● They committed to take firm action against drug-resistant forms of the disease, build accountability and to prioritize human rights issues such as the stigma that still prevails around TB in many parts of the world.

● The political declaration is the culmination of recent leadership commitments at global and regional level including the 2017 Moscow Declaration to End TB.

● The declaration is asserted to drive universal access, sufficient and sustainable financing, intensified research and innovation, and accountability across all sectors to eliminate the TB.

Program Towards Elimination of Tuberculosis

● Recently, India and the World Bank signed a $400 million dollar loan agreement for the programme.

● It covers 9 states and supports the National Strategic Plan to end TB in India by 2025.

● It also includes monitoring of drug resistant TB cases.

● It also supports Nikshay - the web enabled patient management system for TB control under the Revised National Tuberculosis Programme (RNTCP).

● India has the highest TB burden in the world.

Child screening programme

● Recently, Leprosy and TB have added to Rashtriya Bal Swasthya Karyakram (RBSK), or “Child Health Screening and Early Intervention Services”.

● The RBSK screen children under 18 years for a set of 30 health conditions.

● These conditions are broadly defects at birth, diseases in children, deficiency conditions and developmental delays including disabilities, together described as 4Ds.

● The programme began in 2013 under the National Health Mission.

Leprosy in India

● The National Leprosy Eradication Programme was launched in 1955.

● India was recently declared to be the “leprosy capital of the world”, housing around 66 percent of all the world’s cases.

● Leprosy was formally declared eliminated in 2005 in India but an estimated 135,485 new cases were detected in the 2016-17 period.

● In 2017, India had set a target of elimination of leprosy by 2018 but failed to keep up with the target.

RTS,S vaccine● The world's first malaria vaccine was launched in Malawi in Africa.

● It was launched after concerted efforts of over 30 years to protect children from the deadly disease that claims over 435,000 lives globally every year.

● It will be made available to children up to 2 years of age.

● The pilot programme is designed to generate evidence and experience to inform WHO policy recommendations on the broader use of the RTS,S malaria vaccine.

● It will look at

○ reductions in child deaths

○ vaccine uptake, including whether parents bring their children on time for the four required doses

○ vaccine safety in the context of routine use

● The vaccine is a complementary malaria control tool -- to be added to the core package of WHO-recommended measures for malaria prevention, including the routine use of insecticide-treated bed nets, indoor spraying with insecticides, and the timely use of malaria testing and treatment.

● Malaria remains one of the world's leading killers, claiming the life of one child every two minutes.

● Most of these deaths are in Africa, where more than 250,000 children die from the disease every year.

● WHO estimates that India accounts for 89 per cent malaria cases in South-East Asia.

● According to National Vector Borne Disease Control Programme (NVBDCP), 1,090,724 cases and 331 deaths due to malaria were reported during 2016 in the country.

● Children under five are at greatest risk of its life-threatening complications.

● Worldwide, malaria kills 435 000 people a year, most of them children.

Significance

● RTS,S/AS01 (RTS,S) is the world’s first malaria vaccine that has been shown to provide partial protection against malaria in young children.

● The vaccine acts against Plasmodium falciparum, the most deadly malaria parasite globally and the most prevalent in Africa.

● Beginning in 2019, it will be the first malaria vaccine provided to young children through routine immunization programmes.

Foot and Mouth Disease and Brucellosis

● The Union Cabinet recently approved an initiative to control Foot and Mouth Disease (FMD) and Brucellosis to support the livestock rearing farmers.

● The initiative pertains to fully control these diseases amongst the livestock in the country in the next five years and subsequently eradicate these diseases.

● These diseases are very common amongst the livestock – cow-bulls, buffaloes, sheep, goats, pigs etc.

● Both the diseases have a direct negative impact on the trade of milk and other livestock products.

Details of the initiative

● In case of FMD, the scheme envisages vaccination coverage to 30 crore bovines (cows-bulls and buffaloes) and 20 crore sheep/goat and 1 crore pigs at six months’ interval along with primary vaccination in bovine calves,

● The Brucellosis control programme shall extend to cover 100% vaccination coverage of 3.6 crore female calves.

● The programme had so far been implemented on cost sharing basis between the Central and State Governments. The Central Government has decided to now bear the entire cost of the programme.

Effect of FMD disease

If a cow/buffalo gets infected with FMD, the milk loss is upto 100% which could last for four to six months.

Effect of Brucellosis

● Further, in case of Brucellosis the milk output reduces by 30%, during the entire life cycle of animal.

● Brucellosis also causes infertility amongst the animals.

● The infection of brucellosis can also be transmitted to the farm workers and livestock owners.

National Action plan for Viral Hepatitis

● It was recently launched by the Ministry of Health and Family Welfare.

● The Plan provides a strategic framework, based on which National Viral Hepatitis Control Program was framed and launched in July, 2018 under National Health Mission by Ministry of Health & Family Welfare.

● This program is also in line with our global commitment towards achieving Sustainable development Goal (SDG). ( By 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases and combat hepatitis, water-borne diseases and other communicable diseases)

● India has affirmed this commitment at the 69th World Health Assembly.

Viral hepatitis

● Viral hepatitis is recognized as an important public health problem across the world.

● According to WHO estimates, viral hepatitis caused 1.34 million deaths globally in 2015, a number comparable to deaths due to tuberculosis, worldwide.

● In India, it is estimated that there are 4 crore people suffering from Hepatitis B and 0.6-1.2 crore people suffering from Hepatitis C.

● India is one of the few countries in the world to roll out management of Hepatitis B and hepatitis C in a public health approach and offer free diagnostics and drugs lifelong to its beneficiaries.

● The aim of the program is to

○ combat hepatitis and achieve countrywide elimination of Hepatitis C by 2030,

○ achieve significant reduction in the infected population, morbidity and mortality associated with Hepatitis B and C viz. Cirrhosis and Hepato-cellular carcinoma (liver cancer) and Hepatitis A and E.

● Integrating the interventions within the existing health systems framework under National Health Mission are further complementing the efforts of increasing access to testing and management of viral hepatitis.

● Coordination and collaboration with other national programs and schemes to provide a promotive, preventive and curative package of services will further augment the government of India’s determined efforts towards achieving the goal.

● Another important strategy adopted by the program is propagating the use of Re-use Prevention (RUP) syringes in the country.

Biotechnology

Preventing mitochondrial diseases

Mitochondria

● They are situated outside the nucleus of the cell

● They are called the power house of a cell.

● It is called so because they produce the energy required for cells to carry out their functions.

● A special feature of the mitochondria is that it has its own DNA called mitochondrial DNA (mDNA).

● It forms only 0.1% of an individual’s DNA.

● While an offspring inherits one set of chromosomes from both parents, it inherits mDNA only from the mother.

● As mitochondria is an important part of cells, diseases caused by mutations in mitochondrial DNA can cause seizures, developmental delays, blindness, and organ failure in children.

● Mitochondrial diseases are associated with many inheritable diseases.

● Such diseases become apparent in childhood and worsens with age.

● It may become fatal within the first few years of life.

● There is no cure for mitochondrial diseases.

● The mother passes on only a small number of mDNA to the offspring and the proportion of mutant mDNA transferred will vary.

● There is a minimum threshold of mutant mDNA that should be present in the offspring to cause mitochondrial disease.

● Detection of mitochondrial diseases also require a detailed study of maternal inheritances.

● Due to limitations of detectability and treatments available for the disease, the only option is to prevent the transmission of the same.

● Mitochondrial Replacement therapy is one such method which isolates the defective mDNA.

Mitochondrial Replacement therapy

● MRT is a therapy used to help couples have children without genetic mutations from parents.

● MRT involves replacing the mitochondrial DNA of an embryo that has a risk of mitochondrial disease with healthy mitochondrial DNA from a donor, or the “third parent.”

● The babies born using MRT therapy are hence called “three parent babies”.

● The United Kingdom became the first country to legalise MRT therapy in 2015.

● It is not legal in USA.

Arguments favouring MRT

● It enables mother with mitochondrial mutations to have healthy children.

● Scientists in favour of MRT say that nuclear DNA is not edited and the therapy is therefore similar to invitro fertilisation.

● It is applying the power of science to prevent devastating and potentially lethal diseases.

● Mitochondrial DNA is responsible only for metabolism. Hence, individual characteristics such as facial features and eye colour determined by nuclear DNA are not affected.

● Also, MRT would be regulated so that it will be allowed for women with serious defects.

Challenges

● It may prompt scientists to create “designer babies” in future.

● The compatibility between mother’s nuclear genes and donor’s mitochondrial genes is also not known. Experiments in mice have shown that such incompatibility may lead to obesity, metabolic disorders, accelerated ageing and other problems.

● The procedure involves harvesting many eggs from the mother and the donor to delineate healthy eggs which raises health risks for women.

● Also the unwanted embryos are discarded which is also unethical.

● It may also raise identity crisis of the child in future.

● The long term effects of the therapy are not known.

● The specific reason for mitochondrial mutation occurring at a lower rate than other DNA is not known.

● Scientists do not know how mitochondrial disease is inherited from the mother.

● Finally, scientists are not 100% sure of the efficiency of the therapy. Some argue that it may not be possible to make nuclear transfer completely free from the mother’s mitochondria. When a baby born of MRT therapy was tested, they found that less than 1% of the mitochondria from mother was present. Since, mitochondrial diseases require 18% of the mitochondria to be affected, scientists hope the therapy would work.

CRISPR-Cas9

● It is short for “clustered regularly-interspaced short palindromic repeats” and “CRISPR-associated protein 9”.

● It is a recently developed genome editing technology.

● It was adapted from a naturally occurring genome editing system in bacteria.

● These organisms use CRISPR-derived RNA and various Cas proteins, including Cas9, to foil attacks by viruses and other foreign bodies.

● They do so primarily by chopping up and destroying the DNA of a foreign invader.

Working of CRISPR-Cas9

● CRISPRs are specialized stretches of DNA.

● It has two characteristics:

○ Sequences of nucleotides (building blocks of DNA) repeated throughout

○ Spacers which are interspersed between the repeated sequences

● Spacers are formed from the viruses that attacked the organism previously.

● The DNA sequence of spacers are identical to that of the virus. It acts as memories which enables CRSIPR to remember the virus that attacked it.

● After each virus attack, new spacers are formed.

● Once a spacer is incorporated and the virus attacks again, a portion of the CRISPR is transcribed and processed into CRISPR RNA, or "crRNA.“

● The protein Cas9 (or "CRISPR-associated") is an enzyme that acts like a pair of molecular scissors, capable of cutting strands of DNA.

● It binds to two RNA molecules: crRNA and another called tracrRNA (or "trans-activating crRNA").

● These RNA molecules guide Cas9 to the target site to cut the double helix of DNA.

● Cas9 identifies the target using short DNA sequences known as PAMs ("protospacer adjacent motifs") which serve as tags and sit adjacent to the target DNA sequence.

● Cells then spring into action to repair the broken sequence.

● This may be done by sticking back both the ends of the cut helix or inserting a new sequence of nucleotides in place of the cut sequence.

● The former process may introduce errors.

● The latter process uses a template for insertion of the new sequence which can be supplied by the scientists.

● Hence, the mutated gene is rewritten which produces the desired result.

Applications

● CRISPR- Cas9 is being used in a variety of fields.

● It is used in food and agriculture industries improve yield, drought tolerance and nutritional properties.

● It can be used to create gene drives. These are genetic systems, which increase the chances of a particular trait passing on from parent to offspring.

● Gene drives can aid in controlling the spread of diseases such as malaria by enhancing sterility among the disease vector — female Anopheles gambiae mosquitoes.

● In addition, gene drives could also be used to eradicate invasive species and reverse pesticide and herbicide resistance.

Benefits

● Faster, cheaper, more accurate, and more efficient than other existing genome editing methods

● It allows for the introduction or removal of more than one gene at a time.

● It is not species-specific, so can be used on organisms previously resistant to genetic engineering.

Challenges

● It is not 100% efficient.

● Editing efficiencies can vary depending on the target.

● DNA may be cut at sites other than the intended target site which can give rise to unintended mutations.

● Even when the system cuts on target, there is a chance of not getting a precise edit.

● In gene drives, an introduced trait could spread beyond the target population to other organisms through crossbreeding. Gene drives could also reduce the genetic diversity of the target population.

● Germline editing (making genetic modifications to human embryos and reproductive cells such as sperm and eggs) can be passed on to subsequent generations raising ethical concerns.

● Germline editing may also cause unintended consequences for future generations.

● It is a process which is being studied. The extent upto which it can be spread is still not known to scientists.

Earth Bio-Genome Project

● The Earth Bio-Genome Project was officially launched in 2018.

● It is a global effort to sequence the genetic code of all the planet’s eukaryotes, including all plants, animals, protozoa and fungi.

● The initiative would produce an open DNA database of biological information.

● It can be used or scientific research and environmental and conservation initiatives.

● The initiative was inspired from Human Genome project.

Genome sequencing

● Human DNA is made of genomes which contains nucleotides or genes - As, Cs, Gs, and Ts in a specific order.

● Genome sequencing involves figuring out the order of these nucleotides.

● Genes account for less than 25 percent of the DNA in the genome.

Advantages of genome sequencing

● It will help scientists in finding genes more quickly.

● It will help scientists study the parts of the genome outside the genes which includes the regulatory regions that control how genes are turned on and off, as well as hitherto unidentified functions of genes.

● It will help in conservation of species at risk of being extinct.

● Scientists would be able to identify new drugs, crops, technologies and the like to adapt to the changing conditions on earth.

Challenges

● Genome sequencing comes with ethical concerns.

● It may not be practically possible to conduct genome sequencing for all species due to accessibility issues.

● Issues associated with intellectual property issues and sharing of benefits may also arise.

MANAV: Human Atlas Initiative

● The Department of Biotechnology recently launched the MANAV.

● It is a project that aims at creating a database network of all tissues in the human body from the available scientific literature.

● The aim of the project remains to understand and capture the human physiology in two stages – in a normal stage and while in a disease stage.

● The student community will be the backbone of the initiative for assimilating the information. They will be trained and imparted with necessary skills to curate the information.

● The teams will also study any potent elements or molecules that have never been used in the form of drugs, to target the specific cells or tissues.

● The programme will involve gaining better biological insights through physiological and molecular mapping, develop disease models through predictive computing and have a wholistic analysis and finally drug discovery.

Significance

● This platform will impart key skills to the student community to read classified scientific literature, on individual tissue-basis, and perform annotation and curation.

● This collated data can be useful for both future researchers and parallelly, to the clinicians and drug developers, who finally handle human bodies in disease conditions.

● Such a database on can come handy in tracing the causes of a disease, understanding specific pathways and ultimately decode the body’s disease stage linked to tissues and cells.

DNA Technology (Use and Application) Regulation Bill, 2019

● It was introduced in and passed by the Lok Sabha in January this year, but lapsed before it could be taken up by the Rajya Sabha.

● It was reintroduced in July 2019 and is now pending in the Lok Sabha.

● It is for the regulation of use and application of DNA technology for the purpose of establishing identity of missing persons, victims, offenders, under trials and unknown deceased persons.

● The primary intended purpose is for expanding the application of DNA-based forensic technologies to support and strengthen the justice delivery system of the country.

● It provides for the mandatory accreditation and regulation of DNA laboratories

○ to ensure that with the proposed expanded use of this technology in this country, there is also the assurance that the DNA test results are reliable, and

○ furthermore that the data remain protected from misuse or abuse in terms of the privacy rights of our citizens.

● It will give fillip to the development of uniform code of practices in all laboratories involved in DNA testing throughout the country.

● This will aid in scientific up gradation and streamlining of the DNA testing activities in the country with appropriate inputs from the DNA Regulatory Board which would be set up for the purpose.

● The proposed legislation will empower the criminal justice delivery system by enabling the application of DNA evidence, which is considered the gold standard in crime investigations.

● Establishment of the National and Regional DNA Data Banks, as envisaged in the Bill, will assist in forensic investigations.

Nobel Prizes

Physics

● The Nobel Prize in Physics 2018 was awarded "for groundbreaking inventions in the field of laser physics”.

● One half of the prize was awarded to Arthur Ashkin "for the optical tweezers and their application to biological systems”

● The the other half was awarded jointly to Gérard Mourou and Donna Strickland "for their method of generating high-intensity, ultra-short optical pulses."

● Strickland became the first woman to receive the award in 55 years after Marie Curie won it in 1903 and Maria Goeppert-Mayer in 1963.

Optical tweezers

● They use a tractor beam-like technology which enable them to grab particles, atoms, viruses and other living cells with their laser beam fingers.

● The tweezers can capture living bacteria without harming them.

● Optical tweezers find applications in biology, microbubbles manipulation, chiral optomechanics, nanotechnology, optical binding, spectroscopy etc.

Optical pulses

● The scientists created ultrashort high-intensity laser pulses without destroying the amplifying material, thus paving the way towards the shortest and most intense laser pulses ever created by mankind.

● Their innovative technique is known as 'chirped pulse amplification' (CPA).

● It has now become standard for high-intensity lasers.

● It is used in corrective eye surgeries.

Chemistry

● The Nobel Prize in Chemistry 2018 was awarded for harnessing the power of evolution.

● One half of the prize was awarded to Frances H. Arnold “for the directed evolution of enzymes”.

● The other half was jointly awarded to George P. Smith and Sir Gregory P. Winter “for the phage display of peptides and antibodies”.

Details

● Enzymes are proteins that catalyse chemical reactions.

● Enzymes produced through directed evolution are used to manufacture everything from biofuels to pharmaceuticals.

● Phage display is a method where a bacteriophage — a virus that infects bacteria — can be used to evolve new proteins

● Antibodies evolved using phage display can combat autoimmune diseases and in some cases cure metastatic cancer

Medicine

● The Nobel Prize 2018 in Medicine was awarded to James P. Allison and Tasuku Honjo “for their discovery of cancer therapy by inhibition of negative immune regulation”.

Details

● Cancer is one of the greatest challenges of mankind as it kills millions of people every year.

● Cancer is characterized by uncontrolled proliferation of abnormal cells with capacity for spread to healthy organs and tissues.

● Though different treatment methods are available, advanced cancer remains immensely difficult to treat.

● The scientists established a new principle for cancer therapy by stimulating the inherent ability of the immune system to attack tumor cells.

● They discovered proteins which function as brakes on the immune cells.

● These proteins prevented immune system from fighting with cancer cells.

● Both scientists showed different strategies for inhibiting the brakes on the immune system.