The Science & Technology Weekly – 29 May – 4 May, 2016

Starting 4th April, 2016 we have a started a new initiative to post Science and Technology Compilation of all articles coming in leading news daily on a weekly basis. We look forward to simplify the preparation of aspirants by easing out their task in one of the most vague topics in UPSC preparation. The compilation will make aspirants aware with day to day happenings in the field of science and technology as well list out basics in brief.
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1. A big boost for public health
2. Enter the superbug?
3. Water sensing from the skies in pipeline
4. How the body turns a toxin into nutrient
5. What defines a monsoon?
6. Australia’s Great Barrier Reef , a third of coral killed due to bleaching
7. An app to keep track of planted saplings
8. New method to create 3D nanoparticles from DNA
9. NASA spots giant coronal hole on Sun
10. Step into your paintings with Google’s Tilt Brush
11. Bad blood: 2,234 get HIV after transfusion
12. Fresh method developed to deal with jet lag
13. TRAI makes its easier to get rid of telemarketers
14. Universe is expanding faster than expected
15. Two foot-long bug declared world’s longest insect
16. Scientists trick body’s viral response to combat cancer
17. Harappa: older than we thought’
18. Walnuts may shield you from colon cancer
19. Scorpenes to become Navy’s mainstay
20. Get ready for plain packaging of tobacco products
21. Thermal stress impacts corals in Indian waters
22. Chemicals of life in comet’s halo
23. Rare ‘Einstein ring’ discovered 

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[1] A big boost for public health

Issue

• Maternal and neonatal tetanus (MNT) is no longer a major public health problem in the World Health Organisation (WHO) South-East Asia region.

Analysis

• The WHO South-East Asia Region has eliminated MNT as a major public health problem.
• As immunisation coverage and access to maternal and newborn health care has increased, the number of mothers and newborns suffering agonising deaths on account of the disease has declined to below one in every 1,000 live births at the district level.
• Unhygienic conditions during delivery and inadequate umbilical cord care saw to it that these toxins could infect mother and child, causing muscle spasms, lockjaw, and often death.

Is it permanently eliminated

• Unlike the situation with diseases such as polio and smallpox, the risk of MNT will always exist. Tetanus spores are always a permanent part of the environment, meaning public health setbacks could once again compromise mothers and their newborns. In relation to MNT, “elimination” must be seen as an enduring pursuit.
• Strengthening measures that facilitated elimination in the first instance can best guarantee the ongoing safety of mothers and their newborns.

Innovative strategies

• Sustaining and enhancing access to quality maternal and newborn health care is critical. By providing expectant mothers the ability to access quality antenatal and safe-birthing services, health systems throughout the region diminish the risk of tetanus infection, as well as other potentially lethal complications.
• There must be innovative strategies deployed to reach those ‘unreached’, such as increased training of skilled birth attendants at community-level facilities, or providing cash transfers to every mother who has an institutional delivery, for example.
• Immunisation coverage must be maintained and enhanced. Expectant mothers must receive the necessary tetanus toxoid vaccine, or combination vaccine, as a matter of priority and at the appropriate stages of pregnancy.
• As Indonesia’s campaign to vaccinate brides-to-be demonstrates that positive initiatives need not be confined to the pregnancy or neonatal periods. Just as newborns receive tetanus immunisations as part of their routine immunisation schedule, children must receive booster doses as and when appropriate. A good place for this to happen is at school.
• Effective engagement with communities is essential. Communities that have difficulties accessing care or which lack experience doing so must be further encouraged to avail themselves of the benefits maternal and newborn health care brings. Messages related to tetanus immunisation and safe-birthing must remain integrated with other outreach activities, and disseminated among the most vulnerable. Harmful traditional practices should be discouraged.

Tracking progress

• A robust and effective surveillance system is vital to tracking progress in these key areas. By closely monitoring incidences of MNT, authorities can evaluate the impact of their efforts, and, if found lacking, better calibrate them in future. In-depth knowledge of the causes of every case of maternal or neonatal tetanus, combined with a resolve to ensure it is not repeated, can be the only appropriate response.

[2] Enter the superbug?

Issue  

• A woman in the U.S. was detected with bacteria resistant to a last-resort antibiotic.

 

What is an antibiotic?

• Antibiotics are medicines used to treat infections or diseases caused by bacteria.

 

Analysis

• The woman was carrying E. coli bearing a new gene, mcr-1, which is resistant to even colistin, the last available antibiotic that works against strains that have acquired protection against all other medication.
• This is the first reported case of the mcr-1 gene in an E. coli strain found in a person living in America.
• Though resistance to colistin has been detected for about 10 years in several countries, the danger from this has been somewhat played down since such resistance was brought about by gene mutations that cannot spread easily between bacteria.
• But mcr-1 poses a threat of an entirely different order; in this case a small piece of DNA (plasmid) found outside the chromosome carries a gene responsible for antibiotic resistance. Since the gene is found outside the chromosome, it can spread easily among different types of bacteria, as well as among patients.

Main Fear about it

• In the case of E.coli , the colistin resistance is not insurmountable as it is still treatable by other known drugs. But were the gene to spread to bugs treatable by only last-resort antibiotics, we could be facing the dreaded — and indeed, long-anticipated — superbug.
• Thus, the discovery of mcr-1 in more countries and settings increases the chances of the emergence and spread of resistance against all available antibiotics. It could well lead to an era without effective drugs to treat bacterial infections — the post-antibiotic age, as it were.

Main Reason for this

• The unchecked use of antibiotics in livestock is a major reason for the development of drug resistance.
• Given the widespread use of colistin in animals, the connection to the drug-resistant mcr-1 gene appears quite clear.
• Besides being administered for veterinary purposes, colistin is used in agriculture.

[3] Water sensing from the skies in pipeline

Issue

• The CSIR-National Geophysical Research Institute (NGRI) is working on a plan to map India’s groundwater reserves by a helicopter-based electromagnetic survey.

How the technology works

• The heliborne transient electromagnetic technique, as it is called, involves sending electromagnetic pulses to the ground — in timed bursts — and analysing the unique pattern that these waves make as they bounce off the freshwater or saline water reserves.

Analysis

• This approach would be less cumbersome than the manual methods now being used to map the groundwater.
• The helicopter-based assessment was used for mineral exploration surveys and would require coordination with the Ministry of Water Resources

[4] How the body turns a toxin into nutrient

Issue

• A pinch of poison is good for a body, at least if it is heme, and researchers have now found how the body turns this toxin into a nutrient known for its role at the core of haemoglobin, the component of red blood cells responsible for transporting oxygen.

Analysis

• In minuscule amounts, heme works in cells as an essential catalyst and as a signalling molecule to trigger other processes.
• Poor heme management can cause things like Alzheimer’s, heart disease, and some types of cancers, so cells have to do a good job of managing how much heme is available
• The labile heme serves as a nutrient instead of a poison. But to make sure things stay that way, heme needs to be trafficked through the cell.
• By having biosensors that can monitor heme in cells, we have this new window into how cells make this essential toxin available in carefully sparse concentrations

[5] What defines a monsoon?

The India Meteorological Department (IMD), the official weather agency, laid down a set of criteria in 2005 to define the monsoon onset in Kerala.

• According to that, at least 8 of 14 meteorological stations Minicoy, Amini, Thiruvananthapuram, Punalur, Kollam, Alappuzha, Kottayam, Kochi, Thrissur, Kozhikode, Thalassery, Kannur, Kasargode and Mangalore ought to report rainfall of 2.5 mm or more for two consecutive days.
• Along with that there ought to be minimum range of wind speed and characteristic heat waves, called Outgoing Longwave Radiation, as well as a steady pattern of monsoon winds at specified height in the atmosphere.
• Only when all of this is satisfied for two days continuously does it count as monsoon.

[6] Australia’s Great Barrier Reef , a third of coral killed due to bleaching

Issue

• Mass bleaching has killed more than a third of the coral in the northern and central parts of Australia’s Great Barrier Reef, though corals to the south have escaped with little damage.

What is Coral Bleeching

• Coral bleaching takes place when the symbiotic relationship between algae (zooxanthellae) and their host corals breaks down under certain environmental stresses. This results in the host expelling their zooxanthellae. In the absence of symbiotic algae, the corals expose their white underlying calcium carbonate coral skeleton and the affected coral colony becomes pale in colour. Coral bleaching can be activated and persist during varied environmental stresses.

Analysis

• Some parts of the reef had lost more than half of the coral to bleaching.
• Though bleached corals that haven’t died can recover if the water temperature drops, older corals take longer to bounce back and likely won’t have a chance to recover before the next bleaching event occurs.
• Coral that has died is gone for good, which affects other creatures that rely on it for food and shelter.

Cause of this

• Experts say the bleaching has been triggered by global warming and El Nino, a warming of parts of the Pacific Ocean that changes weather worldwide.
• Hot water puts stress on coral, causing it to turn white and become vulnerable to disease. Other reefs have suffered even more severely from the recent bleaching; Some Pacific islands, for example, have reported over 80 per cent coral death rates.
• This is the third and most extreme mass bleaching event in 18 years to strike the Great Barrier Reef, and in each case, the areas that suffered the worst bleaching were the areas where the water was hottest for the longest period of time.
• This time, the southern half of the reef was spared largely due to a lucky break that arrived in the form of a tropical cyclone. The remnants of the storm which had lashed the South Pacific brought cloud cover and heavy rains to the region, cooling the ocean enough to stop bleaching that had just begun in the south. About 95 per cent of the coral in the southern portion of the reef has survived.

[7] An app to keep track of planted saplings

Issue

• Treeism, an  app has been developed by the Vata Foundation with an aim to keep track of the saplings that they will start distributing between June and August this year.

How it works

• At the time of handing over the sapling, the details of the person will be taken along with the picture of the sapling and uploaded on the app. The monthly progress of the sapling will also be up for everyone to track.

[8] New method to create 3D nanoparticles from DNA

Issue

• Scientists have developed an algorithm that uses DNA strands to automatically build 3D nanoparticles, which may be used in a range of applications such as vaccines, gene editing tools and memory storage.

Analysis

• Researchers can build complex, nanometre-scale structures of almost any shape and form, using strands of DNA. However, these particles must be designed by hand, in a complex and laborious process. This has limited the technique, known as DNA origami, to just a small group of experts in the field.
• Unlike traditional DNA origami, in which the structure is built up manually by hand, the algorithm starts with a simple, 3D geometric representation of the final shape of the object, and then decides how it should be assembled from DNA.
• The technique may be used to develop nanoparticles for a much broader range of applications, including scaffolds for vaccines, carriers for gene editing tools, and in archival memory storage.

How it works

• The algorithm first represents the object as a perfectly smooth, continuous outline of its surface. It then breaks the surface up into a series of polygonal shapes.
• Next, it routes a long, single strand of DNA, called the scaffold, which acts like a piece of thread, throughout the entire structure to hold it together.
• The algorithm weaves the scaffold in one fast and efficient step, which can be used for any shape of 3D object.

[9] NASA spots giant coronal hole on Sun

Issue

• NASA’s Solar Dynamics Observatory has spotted a giant dark area on the upper half of the Sun known as a coronal hole.

What is coronal hole?

• Coronal holes are areas on the Sun where the solar magnetic field extends up and out into interplanetary space, sending solar material speeding out in a high-speed stream of solar wind.

Analysis

• Scientists study these fast solar wind streams because they sometimes interact with Earth’s magnetic field, creating what is called a geomagnetic storm, which can expose satellites to radiation and interfere with communications signals.
• Coronal holes are low-density regions of the Sun’s atmosphere, known as the corona. They contain little solar material and have lower temperatures, thus appearing much darker than their surroundings.
• Coronal holes are visible in certain types of extreme ultraviolet light, which is typically invisible to our eyes.
• These coronal holes are important to understand the space environment around Earth through which technology and astronauts travel.
• Coronal holes are the source of a high-speed wind of solar particles that streams off the Sun around three times faster than the slower wind elsewhere.
• While it is unclear what causes coronal holes, they correlate to areas on the Sun where magnetic fields soar up and away, without looping back down to the surface, as they do elsewhere.

[10] Step into your paintings with Google’s Tilt Brush

Issue

• With each passing day, bigger steps in virtual reality is being realised. The Google Tilt Brush software helps create 3D art in a room-size virtual space.

How it works

• Tilt Brush probably is creativity at its best. A painter can move around and create art of any kind in the virtual space, change the colour palette, texture, draw suns and stars or water or fire.
• The console that enables all this is the HTC Vive.
• The VR simulator comes with a headset, two wireless controllers and two base stations.
• The wireless controllers become the brush and palette for Tilt Brush and then the possibilities are endless.
• One can set up HTC Vive console, install the games and applications platform Steam and launch Tilt Brush.

[11] Bad blood: 2,234 get HIV after transfusion

Issue

• In the last 17 months alone, 2,234 persons across India have been infected with human immunodeficiency virus (HIV) while getting blood transfusions.

Analysis

• The data was revealed by National AIDS Control Organization (NACO) in response to a Right to Information query.
• The maximum number of such cases — 361 — was reported from Uttar Pradesh due to unsafe blood transfusion practices in hospitals. Gujarat with 292 cases, Maharashtra with 276 and Delhi with 264 cases are the other leading States where patients have been transfused unsafe blood.
• In India, NACO has been primarily responsible for ensuring provision of safe blood. According to law, it is mandatory to screen donors/donated blood for transmissible infections of HIV, HBV and hepatitis C, malaria and syphilis.
• NACO’s total blood collection was around 30 lakh units. Nearly 84 per cent of the donated blood units came from Voluntary Blood Donation, which seem to be the source of the problem.
• In some cases, the donor may be in a window period — before his HIV viral load can be detected — when he donates the blood. In such cases, when screened, the blood sample shows a false negative.
• Children less than 15 years of age accounted for 7 per cent or 1.45 lakh of all infections in 2011 while 39 per cent (8.16 lakh) were among women.

[12] Fresh method developed to deal with jet lag

Issue

 

• Scientists have designed new molecules that can modify the sleep/wake cycle, paving the way for improved treatments for jet lag and sleep disorders.

What is jet lag?

• Extreme tiredness and other physical effects felt by a person after a long flight across different time zones.

Analysis

• The negative impacts of jet lag and shift work could be significantly reduced if it were possible to reset our 24-hour natural circadian or sleep/wake cycle.
• Scientists have synthesised molecules that can shorten the circadian period. These molecules act directly on one of our “clock proteins

Biological clock

• Most living organisms have a biological clock that resets every 24 hours, regulating functions such as sleep/wake cycles and metabolism. When this cycle is disrupted, like in jet lag, sleep disorders occur, they said. Long-term sleep loss may affect the cardiovascular, endocrine, immune and nervous systems with severe consequences including hypertension, obesity and mental health disorders, among others.

[13] TRAI makes its easier to get rid of telemarketers

Issue

• Telecom regulator TRAI has rolled out ‘DND (do not call) Services’ mobile application for easier management of unsolicited calls and messages by the cell phone users.

Analysis

• TRAI has developed a mobile App for easy registration of UCC complaints to the service providers. With this App, the consumer can also check the status of his complaint. The app is available in the Google App store and Mobile Seva App store.
• TRAI issued ‘The Telecom Commercial Communications Customer Preference Regulations (TCCCPR),2010’ in December 2010 with the objective to provide an effective mechanism for curbing Unsolicited Commercial Communications (UCC).
• The regulations have been framed keeping in view the interest of the customers and telemarketers while ensuring effective implementation

[14] Universe is expanding faster than expected

Issue

 

• The universe is expanding 5 to 9 per cent faster than thought, astronomers using NASA’s Hubble Space Telescope have discovered.

Importance of this finding

• This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95 per cent of everything and don’t emit light, such as dark energy, dark matter, and dark radiation.

How it was done

• Researchers made the discovery by refining the universe’s current expansion rate to unprecedented accuracy, reducing the uncertainty to only 2.4 per cent.The team made the refinements by developing innovative techniques that improved the precision of distance measurements to faraway galaxies.
• They looked for galaxies containing both Cepheid stars and Type Ia supernovae. Cepheid stars pulsate at rates that correspond to their true brightness, which can be compared with their apparent brightness as seen from Earth to accurately determine their distance.
• Type Ia supernovae, another commonly used cosmic yardstick, are exploding stars that flare with the same brightness and are brilliant enough to be seen from relatively longer distances.
• By measuring about 2,400 Cepheid stars in 19 galaxies and comparing the observed brightness of both types of stars, researchers accurately calculated distances to roughly 300 Type Ia supernovae in far—flung galaxies.
• They compared those distances with the expansion of space as measured by the stretching of light from receding galaxies.
• The team used these two values to calculate how fast the universe expands with time, or the Hubble constant.

[15] Two foot-long bug declared world’s longest insect

Issue

• A bug, measuring over half-a-metre long, discovered in southern China has been declared the world’s longest insect.
• A stick insect measuring 62.4 centimetres found two years ago in the southern province of Guangxi has broken the record for length amongst the world’s 807,625 known insects.

Analysis

• The previous record-holder was a Malaysian 56.7-centimetre-long stick insect discovered in 2008 and now on display in London’s Natural History Museum.

[16] Scientists trick body’s viral response to combat cancer

Issue

• German researchers presented a Trojan horse method of attacking cancer, sneaking virus impersonators into the human body to unleash an anti-tumour immune offensive.

How it works

• Tested in only three people so far, the treatment claims to be the latest advance in immunotherapy, which aims to rouse the body’s own immune army against disease.
• Made in the lab, this Trojan horse is composed of nanoparticles containing cancer RNA — a form of genetic coding — enclosed by a fatty acid membrane.
• The particles are injected into patients to simulate a virus invasion, and infiltrate specialised immune cells.
• These so-called dendritic cells decode the RNA imbedded in the nanoparticles — triggering, in turn, the production of cancer antigens.
• The antigens then activate cancer-fighting T-cells, and thus prime the body for an all-out, anti-tumour assault.
• The new treatment is called an RNA vaccine — it works just like a preventive vaccine by mimicking an infectious agent and training the body to respond to it.

About Cancer

• Unlike viruses, bacteria or fungi which can be targeted with drugs, cancer cells are not intruders but our own cells gone haywire due to DNA damage.
• This explains why they mostly circulate undisturbed by the body’s immune system.
• Finding drugs that can kill diseased cells without harming healthy ones has proven very difficult.
• Chemotherapy, for example, targets fast-dividing cells — good and bad alike. Immunotherapy seeks to activate the body’s own immune response without killing healthy cells.

[17] Harappa: older than we thought’

Findings

• Climate change was probably not the sole cause for the collapse of the Harappan civilisation in the Indus-Ghaggar-Hakra river valleys, say Indian scientists, highlighting that the the Harappans “did not give up” despite the decline in the monsoon.
• The recent research by a team of researchers from IIT Kharagpur, Institute of Archaeology, Deccan College Pune, Physical Research Laboratory and Archaeological survey of India (ASI) also shows that the civilisation itself was much older than thought — it is at least 8,000 years old.

After Monsoon decline how farming practice was changed

• They switched from water-intensive crops when monsoon was stronger to drought-resistant crops when it was weaker.
• Their study suggests that other causes, like change in subsistence strategy, by shifting crop patterns rather than climate change was responsible for the Harappan collapse.
• These people shifted their crop patterns from the large-grained cereals like wheat and barley during the early part of intensified monsoon to drought-resistant species of small millets and rice in the later part of declining monsoon, and thereby changed their subsistence strategy.
• The findings come from a major excavated site of Bhirrana in Haryana that shows preservation of all cultural levels of this ancient civilisation from the pre-Harappan Hakra phase through the Early Mature Harappan to the Mature Harappan time.
• Bhirrana was part of a high concentration of settlements along the now dried up mythical Vedic river ‘Saraswati’, an extension of Ghaggar river in the Thar desert.
• To find out how old the civilisation is, the researchers dated pottery of the Early Mature Harappan time — by a technique called optically stimulated luminescence (OSL) — and found it to be nearly 6,000 years old, the oldest known pottery so far. The levels of pre-Harappan Hakra phase have been dated as old as 8,000 years.

Way forward

• It is very interesting to investigate how these ancient people coped with the then climate change and can be a lesson for today’s impending disaster of climate change.

[18] Walnuts may shield you from colon cancer

Issue

• Eating 28 grams of walnuts everyday may change gut bacteria in a way that suppresses colon cancer, a new research has found.

Findings

• Results show for the first time that walnut consumption may reduce colon tumour development.
• There is accumulating evidence that eating walnuts may offer a variety of benefits related to health issues like cancer. This study shows that walnuts may also act as a probiotic to make the colon healthy, which in turn offers protection against colon tumours.
• Walnuts are packed with compounds known to be important nutritionally. They have the most polyunsaturated fatty acids of all the commonly eaten tree nuts, as well as the highest ratio of omega-3 to omega-6 fatty acids, and high levels of a form of Vitamin E with anti-cancer properties.
• But walnuts are not merely the sum of their chemical parts, and it may be as a whole food that they pack the most significant anti-cancer punch against colon cancer, the third most common cancer in the world.
• To figure out why walnuts were beneficial, the team took fecal samples from the mice and analysed the communities of bacteria living in their digestive tracts.
• They found that walnut consumption tended to push the gut microbiome toward an ecology that was potentially protective against cancer.
• Because the studies were done only in mice, more testing needs to be done in humans before walnuts can be unequivocally recommended as a cancer-prevention agent.

[19] Scorpenes to become Navy’s mainstay

Issue

• French Scorpenes will replace Russian Kilo class vessels as the mainstay of the Navy’s conventional submarine fleet in a few years.

Analysis

• Mazgaon Dock Ltd., Mumbai, commissioned a second submarine assembly workshop. Six Scorpenes are under construction in the first one.
• This second workshop will cater to building additional submarines as and when the government takes a decision.
• Having once abandoned the German HDW submarine line in the past, government sources said they were determined not to lose the technical expertise and skilled manpower gained from construction of the six Scorpenes.
• The new assembly workshop built at a cost of Rs.153 crore is a pre-engineered building structure to handle construction of five submarines simultaneously, MDL officials said. It can be used to construct additional Scorpenes or the new line of submarines under Project-75I as and when it is selected.
• But the Request for Proposal (RFP) for P-75I is held up for want of clarity on Strategic Partnerships under the new Defence Procurement Procedure. The proposal from the Ministry intended to promote domestic manufacturing capabilities in critical areas has generated a mixed response and consultations are on to get a consensus. With current platforms fast ageing, Scorpenes will play a major role in ensuring fleet strength.

[20] Get ready for plain packaging of tobacco products

Issue

• Following Australia’s example, for this year’s World No Tobacco Day on May 31 the World Health Organisation is calling on countries to “get ready for plain packaging of tobacco products.

What is  plain packaging?

• Plain packaging refers to “measures to restrict or prohibit the use of logos, colours, brand images or promotional information on packaging other than brand names and product names displayed in a standard colour and font style (plain packaging)”.

Analysis

• Against all odds, Australia was the first country to successfully introduce plain packaging in 2012 and has since seen a decline in smoking.
• During the first week of May 2016, the tobacco companies lost a long-run legal challenge against the European Union rules that force them to print graphic images on both sides that cover two-thirds of a cigarette packet. The Court said that the 28 member states can go beyond the requirements of the European directive and introduce plain packaging.
• France, Ireland, and the U.K. have passed legislation that makes plain packaging mandatory from May 20 this year.
• Experimental studies, surveys and focus group studies have also found that plain packaging achieves its objectives — deter young people from taking up smoking in the first place than making smokers to quit.
• According to WHO tobacco packaging is a mobile billboard promoting consumption of tobacco products. Tobacco packaging makes products more attractive, advertises and promotes tobacco consumption, distracts from health warnings and deceives people into thinking that some products are less harmful than others. Plain packaging helps reveal the grim reality of tobacco products.
• Although some countries have successfully taken on the Big Tobacco by introducing plain packaging, globally tobacco control has been very uneven. The “least compliant countries are often the ones with the highest rates of tobacco use.

Way Forward

• Despite tremendous pressure from tobacco companies India stood its ground by introducing pictorial warning covering 85 per cent of the front and back sides of all tobacco products. The next step for India should be to go in for plain packaging.
• There is every reason for India to introduce plain packaging as nearly 1 million people die each year due to tobacco-related diseases. And like Australia, the taxes should be raised steeply to deter young people from smoking and chewing tobacco products.

[21] Thermal stress impacts corals in Indian waters

Issue

• Coral ecosystem thriving in the Indian waters has come under severe stress with instances of coral bleaching being reported from islands of Lakshadweep and some parts of Andaman.

Finding

• It is the thermal stress in the form of increase in Sea Surface Temperature (SST) during April that has proved disastrous for the corals.
• While bleaching has been widely reported in the coral islands of Lakshadweep, some isolated incidents were reported from Andaman.
• During the last couple of months, an increase in the Sea Surface Temperature was observed in the waters around the Andaman Islands, the Gulf of Mannar, and the Lakshadweep Islands. Following the observations, warning was sounded in these areas for coral bleaching. The in-situ observations carried out at North Bay, South Andaman revealed the primary signs of bleaching.

What is coral bleaching?

• Coral bleaching takes place when the symbiotic relationship between algae (zooxanthellae) and their host corals breaks down under certain environmental stresses. This results in the host expelling their zooxanthellae. In the absence of symbiotic algae, the corals expose their white underlying calcium carbonate coral skeleton and the affected coral colony becomes pale in colour. Coral bleaching can be activated and persist during varied environmental stresses.

Coral regeneration

• Amidst growing concern about the impact of coral bleaching, scientists have also brought out some good news from the ocean depths of Andaman. The branching corals that were destructed during the 2004 South Asian tsunami have started regenerating in the region. The impact of bleaching would be different in different species and some may take 10 years or longer to regenerate.

[22] Chemicals of life in comet’s halo

Issue

• Scientists have found further evidence supporting the theory that some of the building blocks for life may have come to Earth from outer space.

Analysis

• Using instruments aboard the European space probe Rosetta, researchers detected glycine and phosphorus in the dusty halo around a comet.
• Glycine is an amino acid, one of the molecules needed to make proteins, while phosphorus is essential for DNA and cells.
• Their presence in the coma enveloping comet 67P/Churyumov—Gerasimenko “supports the idea that comets delivered key molecules for prebiotic chemistry throughout the solar system and, in particular, to the early Earth.
• Scientists say adding a high concentration of those molecules to a body of water could have produced the “primordial soup” that gave birth to life on our planet more than 4 billion years ago.
• The beauty of it is that the material in the comet was formed before the Sun and planets formed, in the cold environment of the star forming region (known as the) molecular cloud. That means what has happened a long time ago in the cloud from which our solar system emerged could happen in all clouds

[23] Rare ‘Einstein ring’ discovered

News:

• An international team of astrophysicists has stumbled upon an unusual astronomical object — an Einstein ring which is a distorted image of a very distant galaxy termed as “the source”.
• The distortion is produced by the bending of the light rays from the source due to a massive galaxy, termed “the lens”, lying between it and the observer.