Daily Prelims Notes 13 June 2024

Daily Prelims Notes

13 June 2024

1. Four new studies report progress towards long-awaited HIV vaccine

Sub: Science and tech

Sec: Health

Discovery of AIDS:

• 1981: Michael Gottlieb, an assistant professor at UCLA Medical Centre, aimed to teach immunology to a post-doctoral fellow. He published a paper on these cases in “Morbidity and Mortality Weekly” which was the first report of acquired immunodeficiency syndrome (AIDS).

HIV:

• HIV attacks CD4, a type of White Blood Cell (T cells)in the body’s immune system. T cells are those cells that move around the body detecting anomalies and infections in cells.
• After entering body, HIV multiplies itself and destroys CD4 cells, thus severely damaging the human immune system. Once this virus enters the body, it can never be removed.
• CD4 count of a person infected with HIV reduces significantly. In a healthy body, CD4 count is between 500- 1600, but in an infected body, it can go as low as 200.
• Weak immune system makes a person prone to opportunistic infections and cancer. It becomes difficult for a person infected with this virus to recover from even a minor injury or sickness.
• By receiving treatment, severe form of HIV can be prevented.

Transmission

• HIV is transmitted from person to person through bodily fluids including blood, semen, vaginal secretions, anal fluids and breast milk.
• To transmit HIV, bodily fluids must contain enough of the virus. A person with ‘Undetectable HIV’ cannot transfer HIV to another person even after transfer of fluids.
• ‘Undetectable HIV’ is when the amount of HIV in the body is so low that a blood test cannot detect it. Treatment can make this possible. But regular monitoring of the same through blood tests is also required.

Symptoms

• Around 80% of people infected with HIV develop a set of symptoms known as Acute Retroviral Syndrome, around 2-6 weeks after the virus enters into body.
• The early symptoms include fever, chills, joint pains, muscle aches, sore throat, sweats particularly at night, enlarged glands, a red rash, tiredness, weakness, unintentional weight loss and thrush.
• A person can carry HIV even without experiencing any symptoms for a long time. During this time, the virus continues to develop and causes immune system and organ damage.

Treatment

• Anti-Retroviral Therapy:
  • It is a combination of daily medications that stop the virus from reproducing.
  • The therapy helps in protecting CD4 cells thus keeping the immune system strong enough to fight off the disease.
  • It, besides reducing the risk of transmission of HIV, also helps in stopping its progression to AIDS (a spectrum of conditions caused by infection due to HIV).
• Stem Cell Transplant:
  • Under this, an infected person is treated with stem cell transplant from donors carrying a genetic mutation that prevents expression of an HIV receptor CCR5.
  • CCR5 is the most commonly used receptor by HIV-1. People who have mutated copies of CCR5 are resistant to HIV-1 virus strain.

Challenges in HIV Vaccine Development:

• Despite significant progress in tackling infectious diseases, AIDS remains without a vaccine or cure.
• HIV’s replication process is highly error-prone, leading to numerous variants.
• HIV has more variants in a single patient than influenza generates globally in a year.

Immune System Response:

• The immune system produces antibodies specific to viral proteins through B-cells.
• Each B-cell produces a unique antibody that binds to a specific protein fragment on a virus.
• Vaccines aim to generate these antibodies in advance to neutralize the virus upon infection.

Broadly Neutralizing Antibodies (bNAbs):

• In the early 1990s, some HIV-infected individuals produced bNAbs that could neutralize many HIV strains.
  • Some of these bNAbs can effectively neutralise more than 90% of circulating strains.
• bNAbs target critical viral protein regions that the virus cannot change without losing infectivity.
• Producing bNAbs takes years, by which time the virus may have evolved.

Germline Targeting Strategy:

• Goal: To induce the immune system to produce bNAbs quickly through a vaccine.
• Three Steps:

1. Identify and Engage B-cells: Increase the population of B-cells that can produce bNAbs.
2. Booster Dose: Guide these cells to generate stronger bNAbs.
3. Refinement: Enhance bNAbs to neutralize a wide range of HIV strains.

Recent Advances:

• Two promising nanoparticle-based vaccines, N332-GT5 and eOD-GT8, have been developed.
• Scripps Research Institute and MIT demonstrated efficacy in mice and macaques.
• These vaccines are undergoing phase-1 clinical trials in humans.
• A protein fragment, g28v2, is being studied as a potential candidate for step II of germline targeting.

Cautious Optimism:

• Recent studies show potential in B-cell-based vaccines for HIV.
• Past failures remind us to remain cautious until proven effective in humans.
• The strategies may also benefit vaccines for other RNA viruses like influenza, coronaviruses, and hepatitis C.

Source: TH

2. India is world’s second largest emitter of nitrous oxide

Sub: Environment

Section: Pollution

India’s Nitrous Oxide (N2O) Emissions:

• India is the second-largest emitter of N2O, contributing nearly 11% of global man-made emissions in 2020, behind China at 16%.
  • The top five country emitters by volume of anthropogenic N2O emissions in 2020 were China (16.7%), India (10.9%), the United States (5.7%), Brazil (5.3%), and Russia (4.6%).
• The primary source of N2O emissions in India is from the use of nitrogen fertilizers in agriculture.
• Factors Driving Emissions:
  • Increasing meat and dairy production leads to higher N2O emissions from manure and nitrogen fertilizers used in animal feed production.
  • Agricultural emissions continue to rise, whereas emissions from fossil fuels and the chemical industry are stabilizing or declining.

Atmospheric Concentrations:

• The atmospheric concentration of N2O reached 336 parts per billion in 2022, 25% above pre-industrial levels.
• In comparison, CO2 concentration was 417 parts per million in 2022.
• While CO2 reduction remains a major focus, the rapid increase and long atmospheric lifespan of N2O highlight the need for urgent mitigation efforts.

Impact of Nitrogen Fertilizers

• N2O emissions from human activities have surged by 40% over the past four decades, with a notable acceleration between 2020 and 2022.
• Agricultural activities, particularly the use of nitrogen fertilizers and animal manure, account for 74% of anthropogenic N2O emissions.
• N2O emissions are responsible for 6.4% of the effective radiative forcing of greenhouse gases, adding approximately 0.1°C to global warming.

Emission Trends and Projections

• IPCC Findings: Recent N2O concentration levels surpass the most pessimistic IPCC scenarios, potentially leading to global temperatures exceeding 3°C by century’s end.
• Paris Agreement Goals: To meet net-zero targets and stabilize global temperatures below 2°C, anthropogenic N2O emissions must decline by at least 20% from 2019 levels by 2050.

Environmental and Health Impact:

• N2O remains in the atmosphere for approximately 117 years, affecting climate and ozone.
• Inefficient use of synthetic nitrogen fertilizers and animal manure also pollutes groundwater, drinking water, and coastal waters.

Greenhouse gases:

• The major greenhouse gases are water vapour, which causes about 36–70% of the greenhouse effect; carbon dioxide (CO2), which causes 9–26%; methane (CH4), which causes 4–9%; nitrous oxide (N2O) that accounts for about 5.6 percent of greenhouse gas emissions from human activities and ozone (O3), which causes 3–7%.

Call to Action

• Report Insights: The report underscores the urgency for India to address N2O emissions from heavily subsidized nitrogen fertilizers.
• Policy Recommendation: Experts suggest repurposing fertilizer subsidies to support alternative agricultural practices and reduce N2O emissions.

Source: TH

3. World Will Amass ‘Major’ Oil Surplus by 2030: International Energy Agency

Sub: Economy

Sec: External Sector

Key Points:

• Forecast by IEA: The International Energy Agency (IEA) predicts a significant surplus of oil by 2030 due to increased production and tempered demand driven by the clean-energy transition.
• Demand and Supply Projections:
  • Global Demand: Expected to level off at 106 million barrels per day (bpd) by the end of the decade.
  • Supply Capacity: Anticipated to reach 114 million bpd.
  • Surplus: This will result in a surplus of 8 million bpd.
• Factors Influencing Demand:
  • Pandemic Rebound: As the effects of the pandemic rebound diminish.
  • Clean Energy Transition: Advancements in clean energy reducing the reliance on oil.
  • China’s Economic Structure: Changes in China’s economic structure impacting global oil demand.
• IEA’s Advice:
  • For Oil Companies: IEA Executive Director Fatih Birol advises oil companies to adjust their business strategies to prepare for the emerging supply surplus.
• OPEC+ Actions:
  • The forecast follows the OPEC+ group’s indication to unwind output cuts to support oil prices.
• Sector-Specific Demand:
  • Developing Asian Countries: Countries like China and India are expected to drive oil demand.
  • Aviation and Petrochemicals: These sectors will continue to contribute significantly to oil demand.
• Overall Demand Trends:
  • Current Demand: Stood at 102 million bpd in 2023.
  • Future Demand: Projected to increase by around 4% by 2030.
• Factors Limiting Demand Growth:
  • Electric Vehicles: The shift towards electric cars.
  • Fuel Efficiency Gains: Improvements in fuel efficiency for conventional vehicles.
  • Declining Use in West Asia: Reduced use of oil for electricity production in West Asia.

Implications:

• The anticipated surplus could impact global oil markets, pricing, and strategic planning for oil companies.
• The ongoing transition to cleaner energy sources underscores the need for adaptability within the oil industry.

Conclusion:

• The IEA’s forecast signals a transformative period for the global oil market, urging stakeholders to adapt to the evolving energy landscape.

International Energy Agency (IEA)

About:

• Establishment: The International Energy Agency (IEA) was established in 1974 in response to the 1973 oil crisis.
• Headquarters: Paris, France.
• Members: Initially founded by 16 OECD (Organisation for Economic Co-operation and Development) countries, the IEA has expanded to include 30 member countries and 8 association countries.
• Objective: The IEA aims to ensure reliable, affordable, and clean energy for its member countries and beyond. It focuses on energy security, economic development, environmental awareness, and global engagement.

4. Physical Research Laboratory Scientists Find Three New Craters on Mars Surface

Sub: Science and tech

Sec: Space sector

Key Points:

• Discovery:
  • Scientists from the Physical Research Laboratory (PRL) in Ahmedabad have discovered three new craters on Mars.
  • The craters are located in the Tharsis volcanic region on Mars.
• Approval and Naming:
  • The International Astronomical Union (IAU) Working Group for Planetary System Nomenclature approved the names for the three craters based on PRL’s recommendation.
• Details of the Craters:
  • Lal Crater:
    • Named after Devendra Lal, a renowned Indian geophysicist and former Director of PRL (1972-1983).
    • Size: 65 km wide.
    • Coordinates: Centered at -20.98° and 209.34°.
  • Mursan Crater:
    • Named after a town in Uttar Pradesh.
    • Size: 10 km wide.
    • Location: Superimposed on the eastern side of the rim of the Lal Crater.
  • Hilsa Crater:
    • Named after a town in Bihar.
    • Size: 10 km wide.
    • Location: Superimposed on the western side of the rim of the Lal Crater.
• Scientific Importance:
  • Lal Crater:
    • Located in the Tharsis volcanic region, the entire area of the Lal Crater is covered with lava.
    • Sedimentary Deposits:
      • Geophysical evidence indicates the presence of materials other than lava, including a 45-meter thick sedimentary deposit in the subsurface.
      • This provides compelling evidence of water movement, transporting large volumes of sediment into the Lal Crater.
    • Significance:
      • This discovery confirms that Mars was once wet, as water moved significant amounts of sediment, indicating past water activity on Mars.

Conclusion:

• The discovery of the three new craters and the evidence of past water activity in the Lal Crater enhances our understanding of Mars’ geological history and its potential to have harbored life. This significant finding highlights the contributions of Indian scientists to planetary science and the study of Mars.

Physical Research Laboratory (PRL)

About:

• Establishment: The Physical Research Laboratory (PRL) was founded in 1947 by Dr. Vikram Sarabhai, who is considered the father of India’s space program.
• Location: Ahmedabad, Gujarat, India.
• Affiliation: PRL operates under the Department of Space, Government of India.

Mission:

• PRL is dedicated to advanced research in space and allied sciences. It focuses on the fundamental aspects of physical sciences, including astronomy, space science, and atmospheric sciences.