20 September, 2020
- Tata Group to unveil India first CRISPR test - (Science &Technology)
- Protection against SARS-CoV-2 may be short-lived - (Science &Technology)
- Tracking cases through sewage analysis - (Science &Technology)
- Rusty Moon - (Science &Technology)
- External debt increases almost 3% to $559 billion at March-end - (Indian Economy)
- Question of the day (Science & Technology)
UPSC Current Affairs: Tata Group to unveil India’s first CRISPR test - Page 09
UPSC Syllabus: Prelims: GS Paper I | Science & Technology | Mains:|GS Paper III | Bio-Technology
Sub Theme: CRISPR Test (Feluda)) | UPSC
- The Tata Group has announced that the Tata CRISPR test, developed by CSIR-IGIB, ‘Feluda’ (Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology) had received regulatory approvals on Saturday from the Drug Controller General of India (DCGI) for commercial roll-out in accordance with the Indian Council of Medical Research (ICMR) guidelines.
- In this regard we will understand the CRISPR and then we will talk about This new test.
How COVID-19 is tested – UPSC
- Rapid anti-body test - These tests are designed to detect a specific protein in the virus that elicits the body’s immune response. In the case of Covid-19, it is the ‘spike protein’ present on the surface of the coronavirus that facilitates its entry into the human cell.
- RT-PCR test – copies of a segment of DNA (deoxyribonucleic acid) are created using an enzyme called Polymerase. The 'chain reaction' signifies how the DNA fragments are copied, exponentially - one is copied into two, the two are copied into four, and so on. However, coronavirus is made of RNA (ribonucleic acid). Therefore to detect coronavirus, RNA is converted into DNA using a technique called reverse transcription.
CRISPR-Cas based test has opened new possibility of Coronavirus testing and will rapidly replace RT-PCR tests.
What is CRISPR - Cas9 technology-UPSC?
- CRISPR – Clustered, regularly interspaced, short palindromic repeats, is the technology and Cas9 is the protein that acts like a scissor.
- CRISPR technology is basically a gene-editing technology that can be used for the purpose of altering genetic expression or changing the genome of an organism.
- This technique is based on the natural defense mechanism found in some bacteria.
- It uses a specific enzyme — Cas9 — to identify and eliminate predetermined genes and DNA sequences.
- The technology can be used for targeting specific stretches of an entire genetic code or editing the DNA at particular locations.
- Its many potential applications include correcting genetic defects, treating and preventing the spread of diseases and improving crops.
- It is a cheaper, more effective, and endlessly adaptable form of gene manipulation, and it seems to work in every model organism.
How CRISPR - Cas9 technology works-UPSC?
- In bacteria, Cas9 carries crRNA — the genetic information of viruses to identify where to make their cuts.
- The specific location of the genetic codes that need to be changed, or “edited”, is identified on the DNA strand, and then, using the Cas9 protein, which acts like a pair of scissors, that location is cut off from the strand. A DNA strand, when broken, has a natural tendency to repair itself.
- If Cas9 is assigned a specific RNA sequence and delivered to cells, it will hunt down corresponding sequences in the cellular DNA housed in the nuclei and perform a double-strand cut, severing the entire helix at a predetermined point.
- Scientists intervene during this auto-repair process, supplying the desired sequence of genetic codes that binds itself with the broken DNA strand.
Why is FELUDA (COVID-19 Test) important?
- High detection rates:
- The test has met high benchmarks, with 96% sensitivity and 98% specificity for detecting the novel coronavirus.
- As good as RTPCR (current Gold Standard)
- The Tata CRISPR test achieves the accuracy levels of the traditional RT-PCR (real-time polymerase chain reaction) tests
- More effective (Time and Money)
- It has quicker turnaround time, less expensive equipment, and better ease of use.
- First Covid-19 test to use CRISPR technology
- The Tata CRISPR test is the world’s first diagnostic test to deploy a specially adapted Cas9 protein to successfully detect the virus causing COVID-19.
- A step towards indigenization
- This marks a significant achievement for the Indian scientific community, moving from R&D to a high-accuracy, scalable and reliable test in less than 100 days.
- It uses indigenously developed CRISPR technology for the detection of the genomic sequence of the SARS-CoV-2 virus.
UPSC Current Affairs: Protection against SARS-CoV-2 may be short-lived Page 09
UPSC Syllabus: Prelims: Science and Technology |Mains: GS Paper III | Science and Technology
Sub Theme: Bio Technology | Treatment of COVID-19 | UPSC
What is CORONA VIRUS-UPSC?
Coronaviruses are a group of RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal.
It is generally known that protective immunity against the four species of common cold coronaviruses does not last for more than year.
This observation suggests that the duration of protection against SARS-CoV-2 reinfection, too, may not be for long.
Reinfection is a common feature of all human coronaviruses.
The researchers measured the antibodies to the nucleocapsid protein — an abundant coronavirus protein — for each seasonal coronavirus. An increase in antibodies was considered a new infection.
With over a dozen cases of reinfection with SARS-CoV-2, first reported from Hong Kong and then from the U.S and recently from India and other countries, as confirmed through genetic sequences, the key question centres around the duration of protection following an infection by SARS-CoV-2 virus.
Sequencing the virus’s genome also helps distinguish between reinfection, where the virus enters the body a second time and infects the person, and reactivation, where the virus remains in an inactive state in the body and later becomes active again.
One way to confirm reinfection is to test whether viral strains from the two infections are different. This is useful because as the virus mutates, different strains of the virus circulate in different regions at different times. Reinfection has been confirmed in many cases as nucleotides present at specific places of the viral RNA from the first infection were different in the viral RNA from the second infection.
Since reinfection can occur, herd immunity by natural infection is unlikely to eliminate SARS-CoV-2. The only safe and effective way to achieve herd immunity is through vaccination.
Observation regarding coronavirus reinfection
- Sustained broadly recognising antibodies did not provide broad protection from subsequent infections
- The researchers were not able to identify strain variation among seasonal coronaviruses that could play a role in susceptibility to reinfection.
Since there is only slightly varying circulating SARS-CoV-2 strains, increased susceptibility to reinfection by divergent virus strains of SARS-CoV-2 is most likely not the case.
Reinfection has implications for vaccine development
- If COVID-19 reinfections are common, it would imply that vaccines might not completely protect against the virus.
- Even those who have been infected with the virus would have to get vaccinated to protect themselves from reinfections.
- We might have to design and use seasonal shots – like with the flu – as a new ‘variant’ of the virus takes over from an older one in the population.
- Choosing the antigen – the component of the virus used in the vaccine to prepare our immune system – is key. Careful mutation studies are required. Analysing the virus’s genome could help us understand which parts of proteins in the virus haven’t changed much. And researchers could use these so called ‘conserved immunodominant areas’ to make vaccines.
UPSC Current Affairs: Tracking cases through sewage analysis – Page-12
UPSC Syllabus: Prelims: Science and Technology |
Sub Theme: Bio Technology |RNA and SARS-CoV-2| UPSC
- Viral RNA monitoring of municipal wastewater is useful for SARS-CoV-2 surveillance at a population-wide level.
- Based on the RNA concentrations in the sludge, the researchers were able to know the swing in cases up to two days before samples could be collected, one–four days before hospital admissions and six–eight days before positive results were reported. The results were published in the journal Nature Biotechnology.
- In communities facing a delay between specimen collection and the reporting of test results, immediate wastewater results can provide considerable advance notice of infection dynamics.
- There are evidences that SARS-CoV-2 RNA is present in the stools of COVID-19 patients and hence in sewage, and of increased RNA concentrations in sewage being correlated with increased number of cases reported days later. Besides delay in seeking a test and reporting of test results, symptoms may take a few days to present once infection sets in.
UPSC Current Affairs: Rusty moon (Page 12)
UPSC Syllabus: Prelims: Science & Technology |
Sub Theme: Space | Chandrayaan and Moon | UPSC
- As per the analysis of the data acquired by the Moon Mineralogy Mapper onboard Chandrayaan-1, there are oxidised iron mineral called hematite (Fe2O3) at high latitudes on the Moon.
- The researchers say that this lunar hematite is formed through oxidation of the iron on the Moon's surface by the oxygen from Earth's upper atmosphere, as more hematite on the lunar nearside has been observed. (Moon is tidally locked with earth, meaning always the same side of the moon face the earth)
- Along with the oxygen, water on the lunar surface and heat from interplanetary dust also helped in the oxidation process.
- Hematite is not absolutely absent on the lunar farside. There, a small amount of iron oxides “might be formed under the presence of water and energies induced by interplanetary dust impacts and then be decomposed to hematite.”
- Hematite formed at lunar craters of different ages may help understand the oxygen of Earth’s atmosphere in the past 2.4 billion years and reveal facts about the evolution of Earth’s atmosphere in the past billions of years.
- Researchers hopes that NASA's ARTEMIS missions can bring some hematite samples, and detailed chemical studies can confirm if the lunar hematite was indeed oxidised by Earth’s oxygen.
UPSC Current Affairs: External debt increases almost 3% to $559 billion at March-end (Page 11)
UPSC Syllabus: Prelims: Indian Economy |Mains: GS Paper III |
Sub Theme: Indian Economy-Debt| UPSC
India’s External Debt: A Status Report: 2019-20-UPSC
The Department of Economic Affairs under the Ministry of Finance has recently published the report " ‘India’s External Debt: A Status Report: 2019-2020’. In this regard, let us look at some of the important highlights of the report.
External Debt of India-UPSC
The External debt includes the total money owed by the Government, Corporations or Indian Citizens to foreign creditors. The Foreign Creditors could be Foreign Government, Multilateral Institutions (World Bank, IMF etc), private commercial banks etc.
Categorisation of External Debt
· Duration of loan- Short-term (less than 1 year) and long-term (more than 1 year)
· Sovereign Debt (Government) and Non-Sovereign Debt ( Other than Government, including private sector)
Major Heads under External Debt
· Multilateral Debt: Debt from the multilateral institutions such as World Bank, IMF, ADB etc.
· Bilateral Debt: Debt from sovereign countries such as Japan, Germany etc.
· Trade Credits/Export Credits: Loans and credits extended for imports directly by overseas supplier, bank and financial institutions
· External Commercial Borrowings: loans from commercial banks, other commercial financial institutions
· Non-Resident Deposits in Banks and Financial Institutions
Present status of External Debt
· Cumulative External Debt: At end of March 2020, India’s external debt was placed at US$ 558 billion (20.6% of the GDP). This is $ 15bn higher as compared to India's external debt of $ 543 bn at the end of March 2019.
· Composition of Debt: Non-Sovereign Debt (Non-Government Debt) : 17% of the GDP; Sovereign Debt (Government Debt): 3.6% of the GDP.
· Components of Debt: External Commercial Borrowings (ECBs) accounting for 40% of external debt remains the largest source of External Debt followed by Non-resident deposits.
· Duration of Debt: Long term debt (maturity of more than 1 year) accounts for 81% of external debt; Short-term debt ( (maturity of less than 1 year) accounts for 19% of external debt
· Denomination of Debt: US dollar (53%); remaining in Rupee, Yen, SDR and Euro.