Current Affairs 5th December 2021

Using superconducting fault current limiters (SFCL).

  • This device uses a superconductor, which allows a dissipation less passage of current under normal circumstances, as it offers zero resistance to current flow in the superconducting state.
  • However, if the current flowing through it increases beyond a threshold value, as during a fault, its resistance increases sharply
  • The array of Hall sensors placed around the SFCL constantly “measure and monitor as well as map” the current flowing inside the superconductor.


Earth Dynamo

  • For long, scientists have built into their theories, the concept of the Earth’s dynamo a wind-driven, electrical generator that spans the space up to nearly a hundred kilometers above the Earth’s surface.
  • Now, using observations from NASA’s ICON mission, scientists have actually measured it.
  • They find that the dynamo churns in the ionosphere and it is powered by tidal winds faster than cyclones. The study, published in Nature Geosciences, can help us better understand space weather.
  • The Earth’s global magnetic field is generated in its metallic core, located nearly 3,000 kilometers beneath the planet’s surface.
  • The field has existed on Earth for at least 3.5 billion years and offers clues about how other planets, stars and celestial bodies may have formed.
  • Dynamo theory the idea that a large dynamo, or magnetic field generator, exists within Earth’s outer core, where liquid iron constantly moves as the planet cools.
  • This continuous motion creates electric currents as electrons move through the liquid.
  • Through this process, the energy of the moving fluid is converted into a magnetic field that can be sustained for billions of years.


NASA ICON mission

  • The Ionospheric Connection Explorer studies the frontier of space: the dynamic zone high in our atmosphere where terrestrial weather from below meets space weather above.
  • In this region, the tenuous gases are anything but quiet, as a mix of neutral and charged particles travel through in giant winds.
  • These winds can change on a wide variety of time scales due to Earth’s seasons, the day’s heating and cooling, and incoming bursts of radiation from the sun.
  • This region of space and its changes have practical repercussions, given our ever-increasing reliance on technology this is the area through which radio communications and GPS signals travel.
  • Variations there can result in distortions or even complete disruption of signals.
  • In order to understand this complicated region of near-Earth space, called the ionosphere, NASA has developed the ICON mission.
  • To understand what drives variability in the ionosphere requires a careful look at a complicated system that is driven by both terrestrial and space weather.
  • ICON helps determine the physics of our space environment and pave the way for mitigating its effects on our technology, communications systems and society.


Bacterium Helicobacter hepaticus

  • A new study by University of Pittsburgh researchers finds that fine-tuning the gut microbiome can help fight colon cancer in mice.
  • In the study, published in Immunity, the researchers added the bacterium Helicobacter hepaticus, a bacterium that inhabits the thick mucous in the gut lining and evokes a strong immune response, to the gut microbiome of mice.
  • They found that it boosted the adaptive immune response, caused a selective activation of helper T cells and B cells leading to a shrinking of colon tumors in the mice.


Naming of omicron

  • On November 26, the World Health Organization designated the newly identified SARS-CoV-2 lineage B.1.1.529 with a whooping 32 mutations in the spike protein alone a variant of concern and named it ‘Omicron’, making it the 13th lineage to receive a Greek letter under its nomenclature system.
  • The Greek letter nomenclature of variants was introduced by the WHO in 2021 as a uniform system of naming variants of interest and concern.
  • This nomenclature system unifies the different systems of nomenclature that have existed since the beginning of the COVID-19 pandemic.
  • These largely include the scientific names assigned by GISAID, the largest open access global database of genome sequences and related data of SARS-CoV-2,

Bypassing stages

  • With the designation of Omicron as a variant under monitoring and further as a variant of concern (VOC) within a short span of two days
  • The WHO bypassed the stage of initially designating it as a variant of interest (VOI), which is a significant departure from the precedence followed for other variants of concern in the past.
  • The rapid pace at which WHO designated Omicron a VOC was a decision that did not come out of haste but was based on concrete scientific evidence which came early from Africa
  • Typically, a variant is designated a VOC if it has evidence that supports one of the three possible factors.
  • Increase in transmissibility or a detrimental change in COVID-19 epidemiology,
  • Increase in virulence or change in clinical disease presentation or decrease in effectiveness of public health and social measures including vaccines, therapeutics and diagnostics.


Thrombocytopenia syndrome (TTS)

  • A multi-institutional study published on December 1 in the journal Science Advances has revealed for the first time the mechanism responsible for blood clots arising from thrombosis with thrombocytopenia syndrome (TTS) following vaccination with AstraZeneca vaccine.
  • Thrombocytopenia syndrome causes low platelet count.
  • A low number of platelets blood cells that help prevent blood loss when vessels are damaged can result in no symptoms or can lead to an increased risk of bleeding or, in some cases, clotting.
  • Thrombosis with thrombocytopenia syndrome is a very rare serious adverse effect following vaccination using chimpanzee adenovirus Y25 (ChAdOx1), human adenovirus type 26 (HAdV-D26), and human adenovirus type 5 (HAdV-C5).
  • The researchers found that all three adenoviruses used in a few COVID-19 vaccines as vectors bind to platelet factor 4 (PF4). They found that adenoviruses form stable complexes with PF4.
  • In very rare cases, the viral vector may enter the bloodstream and bind to PF4, where the immune system then views this complex as foreign.
  • The scientists believe this misplaced immunity could result in the release of antibodies against PF4, which bind to and activate platelets, causing them to cluster together and triggering blood clots in a very small number of people after the vaccine is administered
  • Heparin may inhibit the proposed interaction between ChAdOx1 and PF4, it does not provide any insights as to the effect of heparin on patients after they develop symptoms or its behavior in the wider biological context.
  • Heparin is an anticoagulant (blood thinner) that prevents the formation of blood clots. Heparin is used to treat and prevent blood clots caused by certain medical conditions or medical procedures. It is also used before surgery to reduce the risk of blood clots.