Daily Prelims Notes 6 October 2020

October 6, 2020
Posted by: OptimizeIAS Team
Category: DPN

No Comments

Table Of Contents

1. Adjuvant in a vaccine

Subject: Science and tech

Context:

Coronavirus vaccine Covaxin will use adjuvant Alhydroxiquim-II to boost immune response and longer lasting immunity.

Concept:

An adjuvant is a substance that is co-injected with antigen in order to help stimulate and enhance the adaptive immune system into producing antibodies against the antigen.
Adjuvants affect the immune response in various ways:
- To increase the immunogenicity of weak antigens
- To enhance speed and duration of immune response
- To stimulate and modulate humoral responses, including antibody isotype
- To stimulate cell-mediated immunity
- To improve induction of mucosal immunity
- Enhance immune responses in immunologically immature patients, particularly infants
- To decrease the dose of antigen required; reducing costs and eliminating inconvenient requirements for booster shots
Many molecules have been considered for use as an adjuvant, including mineral compounds (e.g. Alum), water-in-oil or oil-in-water emulsions (e.g. Freund’s adjuvant), as well as natural and synthetic toxins derived from bacteria (e.g. cholera toxin, CT and lymphotoxin, LT).
Based on their mechanism of action, adjuvants have been categorised into two broad groups; the particulate vaccine-delivery systems that target antigen to antigen presenting cells (APCs) and the immunostimulatory adjuvants that directly activate such cells through specific receptors e.g. toll-like receptors (TLRs) resulting in inflammatory responses that amplify the innate immune response.
The ultimate aim is to activate the innate immune system to respond more rapidly to infection and for the adaptive immune response to become more specific.

2. Hepatitis C

Subject: Science and tech

Context:

Three scientists who discovered the virus Hepatitis C have won the 2020 Nobel Prize in Medicine or Physiology.

Concept:

Hepatitis is an inflammation of the liver. The condition can be self-limiting or can progress to fibrosis (scarring), cirrhosis or liver cancer.
Hepatitis viruses are the most common cause of hepatitis in the world but other infections, toxic substances (e.g. alcohol, certain drugs), and autoimmune diseases can also cause hepatitis.
There are 5 main hepatitis viruses, referred to as types A, B, C, D and E. These 5 types are of greatest concern because of the burden of illness and death they cause and the potential for outbreaks and epidemic spread.
In particular, types B and C lead to chronic disease in hundreds of millions of people and, together, are the most common cause of liver cirrhosis and cancer.
Scientists have identified 5 unique hepatitis viruses, identified by the letters A, B, C, D, and E. While all cause liver disease, they vary in important ways.
- Hepatitis A virus (HAV) is present in the faeces of infected persons and is most often transmitted through consumption of contaminated water or food. Certain sex practices can also spread HAV. Infections are in many cases mild, with most people making a full recovery and remaining immune from further HAV infections. However, HAV infections can also be severe and life threatening. Most people in areas of the world with poor sanitation have been infected with this virus. Safe and effective vaccines are available to prevent HAV.
- Hepatitis B virus (HBV)is transmitted through exposure to infective blood, semen, and other body fluids. HBV can be transmitted from infected mothers to infants at the time of birth or from family member to infant in early childhood. Transmission may also occur through transfusions of HBV-contaminated blood and blood products, contaminated injections during medical procedures, and through injection drug use. HBV also poses a risk to healthcare workers who sustain accidental needle stick injuries while caring for infected-HBV patients. Safe and effective vaccines are available to prevent HBV.
- Hepatitis C virus (HCV) is mostly transmitted through exposure to infective blood. This may happen through transfusions of HCV-contaminated blood and blood products, contaminated injections during medical procedures, and through injection drug use. Sexual transmission is also possible, but is much less common. There is no vaccine for HCV.
- Hepatitis D virus (HDV) infections occur only in those who are infected with HBV. The dual infection of HDV and HBV can result in a more serious disease and worse outcome. Hepatitis B vaccines provide protection from HDV infection.
- Hepatitis E virus (HEV) is mostly transmitted through consumption of contaminated water or food. HEV is a common cause of hepatitis outbreaks in developing parts of the world and is increasingly recognized as an important cause of disease in developed countries. Safe and effective vaccines to prevent HEV infection have been developed but are not widely available.

3. RRBs

Subject: Economy

Context:

As of March-end 2019, 11 RRBs had a collective accumulated loss of ₹2,887 crore.

Concept:

Regional Rural Banks (RRBs) were formed under the RRB Act, 1976 with an objective to provide credit and other facilities to small farmers, agricultural labourers and artisans in rural areas.
Regional Rural Banks were set up on the basis of the recommendations of the Narasimham Working Group (1975), and after the legislations of the Regional Rural Banks Act, 1976.
The first Regional Rural Bank “Prathama Grameen Bank” was set up on October 2, 1975.
As per the law, the Centre holds 50 per cent stake in RRBs, while 35 per cent and 15 per cent are with the concerned sponsor banks and state governments, respectively.

4. SMART

Subject: Science and tech

Context:

India successfully tests ‘game changer’ SMART torpedo system for anti-submarine warfare

Concept:

Supersonic Missile Assisted Release of Torpedo (SMART) is a missile assisted release of lightweight anti-submarine torpedo system for anti-submarine warfare (ASW) operations far beyond the torpedo range.
All the mission objectives (of SMART) including missile flight upto the range and altitude, separation of the nose cone, release of torpedo and deployment of velocity reduction mechanism (VRM) have been met perfectly
SMART, when launched from warship or a truck-based coastal battery, takes off like a regular supersonic missile.
It covers most of its flight in the air at lower altitudes with two-way data link from the warship or an airborne submarine target detection system and provides the exact location of the hostile submarine to correct its flight path midway.
Just when it approaches close enough to the submerged submarine, the missile will eject the torpedo system into the water and the autonomous torpedo will start moving towards its target to take out the submarine.

5. Buy Back

Subject: Economy

Context:

TCS company plans for a buy back

Concept:

A buyback, also known as a share repurchase, is when a company buys its own outstanding shares to reduce the number of shares available on the open market.
Since companies raise equity capital through the sale of common and preferred shares, it may seem counter-intuitive that a business might choose to give that money back.
However, there are numerous reasons why it may be beneficial to a company to repurchase its shares, including ownership consolidation, undervaluation, and boosting its key financial ratios.

6. Amazon to become savannah

Subject: Environment

Context:

Amazon could be on the verge of losing its distinct nature and switching from rainforest to an open savana as resulting climate change.

Concept:

The Amazon forest in Brazil has experienced 74,155 fires since January 2019 and it became worst in a decade with the 60% increase in fire hotspot compared with last year.
Rainforest support vastly greater number of species than a savannah and play a much greater role in absorbing carbon dioxide from the atmosphere.
Rainforest are highly sensitive to changes in rainfall and moisture levels, fires and prolonged droughts can result in areas to Savana like mix of woodland and grassland.
The continued destruction of human activities (fire and loggers) would bring the region closer to a tipping point where rainforest could turn to savannah.

Advantages of rainforest:-

It is the most biologically diversified forest on the earth which is efficient to produce their own self – sustaining rainfall in the region.
The trees like mahogany, rosewood, mangroves are found in the forest and also different species of mammals, reptiles found in the forest.

Effects of savannah climate on Amazon forest:-

Lost of large area of the rainforest will drastically reduce the rainfall level in the region.
About 40% of the forest is now reduced to the level could be expected to as savannah instead.
Drier condition make it harder for the forest to recover and increase the inflammability of the eco system, worst scenario is that it will take decade long to return to their original state.

7. Keto diet

Subject: Science and tech

Context:

There is fear of kidney failure in following a ketogenic diet.

Concept:

The ketogenic diet is one of the most popular weight loss diets the world over.
It is a high-fat, moderate-protein and low-carb diet that helps in weight loss by achieving ketosis — a metabolic state where the liver burns body fat and provides fuel for the body, as there is limited access to glucose.
A classic keto requires that 90 per cent of a person’s calories come from fat, six per cent from protein and four per cent from carbs.

8. Vaccine nationalism

Subject: IR

Context:

Even as the novel coronavirus vaccine is still a few months away, several wealthier countries like Britain, France, Germany and the US have entered into pre-purchase agreements with Covid-19 vaccine manufacturers

Concept:

When a country manages to secure doses of vaccines for its own citizens or residents and prioritises its own domestic markets before they are made available in other countries it is known as ‘vaccine nationalism’.
This is done through pre-purchase agreements between a government and a vaccine manufacturer.
In order to bring about equitable and broad access, WHO, the Coalition for Epidemic Preparedness Innovations, and Gavi have come up with an initiative known as “Covax Facility”.
The facility aims to procure at least two billion doses of Covid-19 vaccines by the end of next year for deployment and distribution mainly in the low- and middle-income countries