(FREE) UPSC Current Affairs 2024 PDF

(Current Affairs) Science & Technology, Defence, Environment | May : 2017

Science & Technology, Defense, Environment

IISC developed molecules to reduce survivability of Mycobacterium tuberculosis (Free Available)
Oxytocin hormone is involved in a broader range of social interactions (Free Available)
Geologists searching for an efficient and cheap way to remove carbon dioxide (Free Available)
IMD says the country is on an average 0.6 degree Celsius hotter than a century ago (Free Available)
A relatively large near-Earth asteroid will fly safely past Earth (Only for Online Coaching Members)
Researchers found a novel way to recycle the mounting pile of electronic waste (Only for Online Coaching Members)
Coastal States of India may not suffer from the massive Arabian Sea algal bloom (Only for Online Coaching Members)
SpaceX successfully launched and then retrieved its first recycled rocket (Only for Online Coaching Members)

IISC developed molecules to reduce survivability of Mycobacterium tuberculosis

Scientists at the Indian Institute of Science (IISc) Bengaluru have developed two new, potent molecules that can severely impact the survival of mycobacteria, including Mycobacterium tuberculosis that causes TB.
The results were published in the journal Antimicrobial Agents and Chemotherapy.
Unlike most antibiotics that target the bacterial metabolism by aiming at the cellular components, the novel molecules inhibit the stress response pathway of mycobacteria.
The stress response pathway is crucial for bacteria to survive during hostile conditions such as lack of nutrients and the presence of antibiotics, to name a few. So any inhibition of this pathway will lead to its death.
The master regulator of stress pathway in the case of mycobacteria is (p)ppGpp (Guanosine pentaphospahte or Guanosine tetraphosphate). Though a molecule that inhibits the (p)ppGpp formation has already been synthesised, the efficacy is not much.
Earlier studies have shown that when the rel gene is deleted, the long-term survival ability under stress was lost; the M. tuberculosis bacteria was unable to persist in mice and unable to form tubercle lesions in guinea pigs.
The major reason for prolonged treatment of TB is the bacterium’s ability to persist in dormant form, which is tolerant to most antibiotics used in the treatment regimen.
So inhibition of (p)ppGpp-mediated persistence could help in shortening the treatment regime, dealing with the emergence of multiple drug resistance and treatment of chronic infections.
Under hostile conditions, bacteria tend to form biofilms, which protect the bacteria from stress and induce tolerance to antibiotics. Both M. tuberculosis and M. smegmatis that do have the Rel gene cannot form a biofilm.
Since there are very few antibiotics that target the stress response pathway of the bacteria, the two molecules offer great promise.

Geologists searching for an efficient and cheap way to remove carbon dioxide

Deep in the jagged red mountains of Oman, geologists are searching for an efficient and cheap way to remove carbon dioxide from the air and oceans and perhaps begin to reverse climate change.
They are coring samples from one of the world’s only exposed sections of the Earth’s mantle to uncover how a spontaneous natural process millions of years ago transformed carbon dioxide into limestone and marble.
As the world mobilises to confront climate change, the main focus has been on reducing emissions through fuel efficient cars and cleaner power plants.
But some researchers are also testing ways to remove or recycle carbon already in the seas and sky.
The Hellisheidi geothermal plant in Iceland injects carbon into volcanic rock. At the massive Sinopec fertiliser plant in China, carbon is filtered and reused as fuel.
In all, 16 industrial projects currently capture and store around 27 million tons of carbon, according to the International Energy Agency.
That’s less than 0.1% of global emissions human activity is estimated to pump about 40 billion tons a year into the atmosphere but the technology has shown promise.
The sultanate boasts the largest exposed sections of the Earth’s mantle, thrust up by plate tectonics millions of years ago. The mantle contains peridotite, a rock that reacts with the carbon in air and water to form marble and limestone.
Rain and springs pull carbon from the exposed mantle to form stalactites and stalagmites in mountain caves.
Carbon dioxide is the primary greenhouse gas driving climate change, which threatens political instability, severe weather and food insecurity worldwide, according to the United Nations climate body.
Natural carbon levels have risen from 280 to 405 parts per million since the Industrial Revolution, and current estimates hold that the world will be 6°C hotter by 2100.
In 2015, 196 nations signed the Paris climate accords, agreeing to curb greenhouse gas emissions to levels that would keep the rise in the Earth’s temperature to under 2°C.
Around 13 tons of core samples from four different sites will be sent to the Chikyu, a state-of-the-art research vessel off the coast of Japan, where Prof. Keleman and other geologists will analyse them in round-the-clock shifts.
Just like in Oman’s mountains, the submerged rock would chemically absorb carbon from the water. The water could then be cycled back to the surface to absorb more carbon from the atmosphere, in a sort of conveyor belt.

A relatively large near-Earth asteroid will fly safely past Earth

A relatively large near-Earth asteroid will fly safely past our planet on April 19 at a distance of about 1.8 million kilometres — over four times the distance from Earth to the Moon, NASA said.
Although there is no possibility for the asteroid to collide with Earth, this will be a very close approach for an asteroid of this size.
The asteroid, known as 2014 JO25, was discovered in May 2014 by astronomers at the Catalina Sky Survey in Arizona, US.
Contemporary measurements by NASA’s NEOWISE mission indicate that the asteroid is roughly 650 meters in size, and that its surface is about twice as reflective as that of the Moon.
At this time very little else is known about the object’s physical properties, even though its trajectory is well known.
The asteroid will approach Earth from the direction of the Sun and will become visible in the night sky after April 19.
It is predicted to brighten to about magnitude 11, when it could be visible in small optical telescopes for one or two nights before it fades as the distance from Earth rapidly increases, NASA said.
Small asteroids pass within this distance of Earth several times each week, but the upcoming close approach is the closest by any known asteroid of this size, or larger, since asteroid Toutatis, a five-kilometre asteroid, which approached within about four lunar distances in 2004.
The next known encounter of an asteroid of comparable size will occur in 2027 when the 800-metre-wide asteroid 1999 AN10 will fly by at one lunar distance, about 380,000 kilometres.
The encounter on April 19 is the closest this asteroid has come to Earth for at least the last 400 years and will be its closest approach for at least the next 500 years.
Also on April 19, the comet PanSTARRS (C/2015 ER61) will make its closest approach to Earth, at a very safe distance of 175 million kilometres, NASA said.

Coastal States of India may not suffer from the massive Arabian Sea algal bloom

The coastal States of India may not suffer from the massive algal bloom that has been reported from the Arabian Sea.
Ocean-watchers had earlier reported that a bloom of the size of Mexico, which originated in the Gulf of Oman, had reached the Arabian Sea and feared that it could reach Indian shores.
Indian National Centre for Ocean Information Services, (INCOIS), confirmed that the algal species green Noctiluca scintillans had bloomed. The presence of the green algae gives deep green colour to the ocean in the areas of spread.
Researchers at INCOIS say that the current bloom was unlikely to impact the coastal States of the country.
The researchers use remote sensing technique for the identification of the bloom species. In-situ studies were also carried out earlier by deploying research vessels to understand the various phases of the algal bloom.
Analysis of the satellite imageries of the bloom areas indicated that it extended from Oman to Gujarat.
Though the extension of the bloom towards Gujarat coast varies annually, typically it remains about 15 km away from the shore.
The decomposition reduces dissolved oxygen from the water column and causes adverse effect on fish. Secondly, degrading Noctiluca cells release ammonia in the water increasing toxic level and it causes fish mortality.
Earlier studies in the bloom area had indicated that there was no significant increase in ammonia or decrease in dissolved oxygen during degrading stage of the bloom in the off shore waters of Gujarat.
Cool dry continental air from the northeast causes an increase in surface density of the sea water due to evaporative cooling and increased salinity.

SpaceX successfully launched and then retrieved its first recycled rocket

SpaceX successfully launched and then retrieved its first recycled rocket, a historic feat and the biggest leap yet in its bid to drive down costs and speed up flights.
It was the first time SpaceX founder Elon Musk tried to fly a booster that soared before an orbital mission.
He was at a loss for words after the Falcon 9 core landed on the bull’s-eye of the ocean platform following lift-off with a broadcasting satellite.
Mr. Musk foresees dozens, if not hundreds of repeat flights, for a booster and rocket turnarounds of as little as 24 hours, perhaps by next year.
Land, refuel and then back up again, with everything leading to one day putting humanity “out there among the stars.”
This particular first stage landed on an ocean platform almost exactly a year ago after a space station launch for NASA.
SpaceX refurbished and tested the 15-story booster, still sporting its nine original engines. It nailed another vertical landing at sea once it was finished boosting the satellite for the SES company of Luxembourg.
SpaceX employees outside jammed Mission Control at the Hawthorne, California, company headquarters cheered loudly every step of the way and again when the satellite reached its proper orbit.