H3N2
1. Context
According to ICMR, the recent uptick in the cases of intense cough lasting for over a week coupled with fever, in several parts of India, can be linked to the Influenza A subtype H3N2 virus. India has recorded the deaths of two people, one each in Karnataka and Haryana, due to the Influenza A subtype H3N2 virus.
2. H3N2 Virus
- Influenza viruses, which cause the infectious disease known as flu, are of four different types: A, B, C, and D.
- Influenza A is further classified into different subtypes and one of them is H3N2.
- According to the United States Centers for Disease Control and Prevention (CDC), H3N2 caused the 1968 flu pandemic that led to the death of around one million people globally and about 100,000 in the US.
- A 2020 study, published in the journal Nature Communications, found that the strains of the virus have dramatically evolved in the past five decades as people born in the late 1960s and 1970s got infected by it as children.
3. Symptoms of H3N2
- Its symptoms are similar to that of any other flu.
- They include cough, fever, body ache and headache, sore throat, a runny or stuffy nose, and extreme fatigue.
- Nausea, vomiting, and diarrhoea have been seen in very few cases.
- According to the Indian Medical Association (IMA), an infection caused by H2N2 generally lasts for five to seven days and the fever starts going away after three days.
- However, the coughing can persist for up to three weeks.
4. Which age group is more vulnerable to this virus?
- As per the IMA, this virus usually preys on individuals below the age of 15 years or above 50 years of age.
- Children and those with co-morbidities like asthma, diabetes, heart disease, weakened immune systems, and neurological or neurodevelopmental conditions are at a higher risk.
5. Preventive Measures
- Self-hygiene is the best way to thwart the spread of H3N2.
- Washing hands before eating or touching your face, nose, or mouth, carrying pocket sanitizer, and avoiding people already infected with the virus or any other seasonal flu are some of the steps one can take to make sure they don't fall sick due to the H3N2 infection.
- Moreover, a healthy diet that includes plenty of fruits and vegetables can also play a significant role in improving immunity.
- Drinking a lot of fluids, and eating home-cooked, low-spice, and low-fat food can also help.
Previous year Question
|
1. Viruses can infect (UPSC 2016)
1. Bacteria
2. Fungi
3. Plants
Select the correct answer using the code given below.
A. 1 and 2 only
B. 3 only
C. 1 and 3 only
D. 1, 2 and 3
Answer: D
2. H1N1 virus is sometimes mentioned in the news with reference to which one of the following diseases? (UPSC 2015)
A. AIDS
B. Bird flu
C. Dengue
D. Swine flu
Answer: D
|
For Prelims
| For Prelims: H3N2 Virus, Indian Medical Association (IMA), Centers for Disease Control and Prevention (CDC), Influenza viruses A, B, C, and D. |
Source: The Indian Express
MACQUARIE ISLAND
1.Background
Macquarie Island, around 1,500km southeast of Tasmania, is more than just a remote rocky outcrop. In fact, it’s the only piece of land on the planet formed completely from ocean floor, which rises above the waves to form peaks that teem with penguins and other bird species, some of them found nowhere else on Earth
These are just some of the reasons this unique island and the seas surrounding it have globally significant conservation values.
2.Protecting the Island
- Macquarie Island and its surrounding seas (to a distance of 5.5km) are already protected as a Tasmanian reserve and the area (this time including seas to a distance of 22km) is also a World Heritage Area
- A Commonwealth marine park also covers most of the southeast quadrant of the island’s “economic exclusion zone”, including a sanctuary zone and two seafloor management zones
- The federal government’s proposed expansion of the marine park would cover the island’s entire economic exclusion zone, increasing the area of Australia’s marine sanctuaries by more than 388,000 square kilometres, an increase larger than the area of Germany
3. Uniqueness of Macquarie Island
- Macquarie Island is the exposed crest of the 1,600km-long undersea Macquarie Ridge, which makes Macquarie Island the only piece of land in the world formed entirely of oceanic crust
- Macquarie Ridge is one of only three such ridges that impede the eastward flow of a current called the Antarctic Circumpolar Circulation, resulting in distinct differences between the west and east sides of the ridge, which are used in different ways by different species
- The oceanography is further divided north to south by two major ocean fronts, the Sub-Antarctic Front and the Polar Front, creating three distinct bodies of water
- They are closer here than anywhere else in the Southern Ocean and as they interact with the Macquarie Ridge create at least six different large-scale oceanographic habitats
- This creates an outstanding spectacle of wild, natural beauty and a diverse set of habitats supporting vast congregations of wildlife, including penguins and seals
- Fifty-seven seabird species, including four species of penguins and four species of albatross, have been recorded on Macquarie Island and 25 of these species have been observed breeding there. The royal penguin and the Macquarie Island imperial shag live nowhere else on Earth
- The ridge includes a series of undersea mountains that act as “stepping stones” linking subantarctic and polar animals on the sea floor, such as brittlestars
- Direct human impacts in the area are predominantly due to fishing and marine debris, although climate change is an ever-present threat too
- The fishery targets the deepwater Patagonian toothfish using bottom longlines, mostly in the central zone of the Macquarie Ridge
- This fishery is generally well regarded for its best-practice fishing methods and commitment to positive environmental outcomes and this fishing activity would continue under the new plans
- But if new fisheries were allowed to develop targeting midwater species, or new industries such as seabed mining were permitted, these could directly impact the seabirds, marine mammals and other species that live in these areas
- Restrictions on potential future fisheries would be determined by the distribution of “sanctuary zones” precluding fishing and “habitat/species zones”, which could accommodate sustainable fishing. Mining would be precluded under either category of protection
4.Way forward
The government’s proposal signals a clear priority for protection over development in this area. A period of public consultation on the proposal will commence in March
Any future development of the marine park would need to be orderly and careful, including prior consideration of environmental impacts
Any changes to the current fishery management arrangements should ensure that the changes maintain or enhance conditions for a long-term sustainable fishery
Source:DownToEarth
GENE EDITING EMBRYOS
1. Context
A Chinese scientist stirred up a hornet’s nest by announcing the birth of gene-edited twins in 2018. A new study warns of the consequences of deploying a technology that is still less understood.
Deleting harmful disease-causing mutations by gene editing could be counterproductive. It could create more problems than it solves
2.Important Observations
- CRISPR can target and edit DNA at precise locations. CRISPR to make the embryos resistant to the human immunodeficiency virus
- Gene editing can be divided into two classes. One involves changing genes in human cells. This method does not alter reproductive cells, such as sperms or eggs. It can be used to treat diseases caused by mutations.
- The second method alters the genome of human embryos. These altered genes can be passed on to future descendants, raising ethical concerns
- The break sites are repaired by human embryos. They do so by copying genetic information from the normal copy of the gene onto the altered strand of the DNA
- CRISPR could lead to extensive gene copying from one parent to the other
- Humans possess two versions of a particular gene received from each parent
- If a child gets a recessive disease-causing gene from one parent and a dominant healthy version of the same gene from the other, they could still be protected.
- The extensive copying of genetic information from one parent to another due to CRISPR could give rise to two mutant copies of the disease-causing gene in the embryo.This significantly increased the risk of diseases
3.Misdiagnosis
The gene-edited embryo should be tested before it is transferred into the uterus. Scientists do this by collecting a small sample from a few or even a single cell
It is then multiplied millions of times using whole genome amplification
Whole genome amplification is a technology that helps increase the amount of DNA samples
The researchers proposed an alternative method that uses stem cells from gene-edited embryos
Stem cells can develop into any functional cells, such as skin cells, muscle cells, liver cells or brain cells
As these stem cells grow indefinitely, they can provide ample DNA material for testing
Source: DownToEarth
CONTROLLED RE-ENTRY OF SATELLITE
1. Context
The Indian Space Research Organisation brought down a satellite in a controlled manner after its end of life, for the first time earlier this week. The weather satellite Megha Tropiques -1, which was developed as a joint mission by Indian and French space agencies, entered the atmosphere after the final two maneuvers and burnt up over the Pacific Ocean.
2. About Megha Tropiques
- Megha- Tropiques is an Indo-French Joint Satellite Mission that studies the water cycle and energy exchanges in the tropics.
- Its objective is to comprehend the life cycle of convective systems that influence tropical weather and climate, as well as their role in the associated energy and moisture budget of the tropical atmosphere.
- It provides scientific data on the contribution of the water cycle to the tropical atmosphere, including information on condensed water in clouds, water vapor in the atmosphere, precipitation, and evaporation.
.png)
Image Source: The Indian Express3. What is the Re-entry of satellite?
- Due to the increasing number of objects in space (Space debris), the international aerospace community has adopted guidelines and assessment procedures to reduce the number of non-operational spacecraft and spent rocket upper stages orbiting the Earth.
- One method of post-mission disposal is to allow the re-entry of these spacecraft, either from natural orbital decay (uncontrolled) or controlled entry.
4. How was the satellite brought down?
- The Megha Tropiques satellite was launched aboard a PSLV by the space agency in 2011. And, although the planned mission life of the satellite was only three years, it continued providing data on the water cycle and energy exchanges in the tropics for nearly a decade.
- With over 120kgs of fuel remaining in the satellite even after being decommissioned, the space agency determined that there was enough to attempt a controlled re-entry, where a series of 20 maneuvers over eight months lowered the orbit of the satellite such that it re-entered the dense atmosphere and burned up.
- This was the first time that the space agency attempted such a maneuver to clear out space debris despite the satellite not being built to do so.
- The re-entry was not really planned as part of the mission; there was fuel left so Isro attempted it. Usually, satellites are left in their orbit and because of the gravitational pull of the earth, they come down to the atmosphere over years and years.
- When the satellites re-enter the atmosphere, the friction causes them to heat up to extremely high temperatures of thousands of degrees Celsius.
- Without a heat shield, 99% of a satellite gets burnt up whether in a controlled re-entry or an uncontrolled one.
5. Why did ISRO attempt a controlled Re-entry?
- Other than extra fuel conveniently remaining in the satellite after the mission life ended, ISRO attempted the controlled re-entry to demonstrate and understand the process of doing so.
- With several space-fairing nations and private entities launching satellites, mostly in low earth orbits, it has become imperative to keep space clean.
- There are thousands of objects flying around in these orbits; not just old satellites and their parts but also the last stages of the rockets that take them there.
- Moving at extremely high speeds even the smallest debris can destroy active satellites.
- In fact, the space agency set up a department last year to monitor space debris and mitigate the risks posed.
- The space agency was also following the guidelines of the UN and the Inter-Agency Space Debris Coordination Committee (IADC) that say satellites should be deorbited after mission life either through controlled entry over a safe impact zone as was attempted by ISRO with Megh Tropiques-1 or by bringing it down to reduce the orbital lifetime to less than 25 years.
6. Space Debris
- Space Debris encompasses both natural meteoroid and artificial (human-made) orbital debris. Meteoroids are in orbit about the sun, while most artificial debris is in orbit about the Earth (hence the term "orbital" debris).
- Orbital debris is any human-made object in orbit about the Earth that no longer serves a useful function. Such debris includes nonfunctional spacecraft, abandoned launch vehicle stages, mission-related debris, and fragmentation debris.
Image Source: NASA7. What happens to satellites usually?
- A controlled re-entry like the one attempted by ISRO earlier this week is possible only for satellites in the low-earth orbit at about 1,000 km over the surface of the earth.
- These maneuvers, however, are not usually attempted because fuel reserves have to be maintained in the satellite after mission life is over.
8. What happens to satellites in these higher orbits?
- They are usually moved to what is known as graveyard orbit. Instead of bringing them down, they are shot upwards at the end of life.
- These orbits are like parking lots in space where all old satellites are put in.
- Sometimes a satellite might escape to deep space as well. A satellite escapes to deep space when its velocity increases enough to get away from the gravitational pull of the earth.
9. Threats due to Debris formation
- Even tiny paint flecks can damage a spacecraft when traveling at these velocities. In fact, millimeter-sized orbital debris represents the highest mission-ending risk to most robotic spacecraft operating in low earth orbit.
- In 1996, a French satellite was hit and damaged by debris from a French rocket that had exploded a decade earlier.
- In the year 2009, a defunct Russian Spacecraft collided with and destroyed a functioning U.S. Iridium commercial spacecraft.
- The collision added more than 2,300 pieces of large, trackable debris and many more smaller debris to the inventory of space junk.
-
China's 2007 anti-satellite test, which used a missile to destroy an old weather satellite, added more than 3,500 pieces of large, trackable debris and much more smaller debris to the debris problem.
Previous year question
| 1. Satellites used for telecommunication relays are kept in a geostationary orbit. A satellite is said to be in such an orbit when: (UPSC 2011)
1. The orbit is geosynchronous. Select the correct answer using the codes given below: A. 1, 2, and 3 only Answer: A 2. Which of the following pair is/are correctly matched? (UPSC 2014) Spacecraft Purpose 1. Cassini-Huygens Orbiting Venus and transmitting data to the Earth 2. Messenger Mapping and investigating the Mercury 3. Voyager 1 and 2 Exploring the outer solar system Select the correct answer using the code given below. A. 1 only
B. 2 and 3 only
C. 1 and 3 only
D. 1, 2 and 3
Answer: B
|
For Prelims & Mains
|
For Prelims: Megha Tropiques, Indian Space Research Organisation (ISRO), International aerospace community, Pacific Ocean, Polar satellite launch vehicle (PSLV), Inter-Agency Space Debris Coordination Committee (IADC), Space Debris.
For Mains: 1. What is the Megha Torpiques- 1 satellite and explain why has ISRO brought down the Megha Torpiques- 1 satellite.
|
Source: The Indian Express
MEASLES AND RUBELLA
1.Context
As the new year dawned, so did a crucial target for India. India had set a target to eliminate measles and rubella (MR) by 2023, having missed the earlier deadline of 2020, due to a variety of reasons, exacerbated by disruptions due to the pandemic
2.Measles and Rubella
2.1.Measles
The measles virus is one of the world’s most contagious human viruses that kills more than 1,00,000 children every year globally, and rubella is a leading vaccine-preventable cause of birth defects, according to the World Health Organization (WHO)
Measles is caused by a single-stranded, enveloped RNA virus with 1 serotype
It is classified as a member of the genus Morbillivirus in the Paramyxoviridae family.
Humans are the only natural hosts of measles virus.
Over the past two decades, the measles vaccine is estimated to have averted more than 30 million deaths globally, as per the WHO’s statistics.
2.2.Rubella
Rubella is a contagious disease caused by a virus
Rubella can cause a miscarriage or serious birth defects in a developing baby if a woman is infected while she is pregnant
A rubella infection is mild for most people, but can cause death or birth defects in an unborn baby
The rubella vaccine is available in combined vaccines that also contain vaccines against other serious and potentially fatal diseases
3.Global Scenario of Measles and Rubella
The measles virus is one of the world’s most contagious human viruses that kills more than 1,00,000 children every year globally, and rubella is a leading vaccine-preventable cause of birth defects, according to the World Health Organization (WHO)
During 2010–2013, India conducted a phased measles catch-up immunisation for children aged 9 months–10 years in 14 States, vaccinating approximately 119 million children
Mission Indradhanush was launched in 2014 to ramp up vaccinating the unvaccinated populationDuring 2017–2021, India adopted a national strategic plan for measles and rubella elimination, and introduced rubella-containing vaccine (RCV) into the routine immunisation programme
As of December 2021, five countries have been verified and have sustained measles elimination - Bhutan, DPR Korea, Maldives, Sri Lanka, Timor-Leste. In addition, Maldives and Sri Lanka have sustained their rubella elimination status in 2022
4. Vaccination
The MMR vaccine is a vaccine against measles, mumps, and rubella, abbreviated as MMR
The first dose is generally given to children around 9 months to 15 months of age, with a second dose at 15 months to 6 years of age, with at least four weeks between the doses
MMR vaccine can prevent measles, mumps, and rubella.
- MEASLES (M) causes fever, cough, runny nose, and red, watery eyes, commonly followed by a rash that covers the whole body. It can lead to seizures (often associated with fever), ear infections, diarrhea, and pneumonia. Rarely, measles can cause brain damage or death.
- MUMPS (M) causes fever, headache, muscle aches, tiredness, loss of appetite, and swollen and tender salivary glands under the ears. It can lead to deafness, swelling of the brain and/or spinal cord covering, painful swelling of the testicles or ovaries, and, very rarely, death.
- RUBELLA (R) causes fever, sore throat, rash, headache, and eye irritation. It can cause arthritis in up to half of teenage and adult women. If a person gets rubella while they are pregnant, they could have a miscarriage or the baby could be born with serious birth defects.
|
Previous Year Questions:
1.Consider the following statements:
Which of the statements given above is/are correct? A. 1 only Answer (B)
2.‘Mission Indradhanush’ launched by the Government of India pertains to (2016) A. immunization of children and pregnant women Answer (A) |
Source:Cdc.gov
