International Current Affairs - 2019
Latest International Current Affairs 2019 with news summaries and current events in International developments, geopolitical, organizations, groupings and fora related updates for India and world with all important national news updates and events for the year 2019.
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Fossil creature Archaeopteryx that lived about 150 million years ago is back on its perch. It has again been brought in the class of Birds.
- Archaeopteryx fossil was discovered in 1861 in Germany.
- It possessed part-bird, part-reptile traits with broad wings and feathers like a bird, but it also had three-fingered claws, sharp teeth and a long bony tail similar to a dinosaur.
- Classified as most primitive bird and as a transition b/w feathered dinosaurs and modern birds.
- Some fossil discoveries of feathered dinosaurs in northeastern China over the past two decades have challenged Archaeopteryx’s place in bird evolution.
- In July 2012, Chinese scientists excavated Xiaotingia zhengi, a previously unknown chicken-sized dinosaur. They carried out a statistical analysis of its anatomical traits that placed it in a group of bird-like dinosaurs called deinonychosaurs.
- Recently an international team led by the Royal Belgian Institute of Natural Sciences used more sophisticated statistical method to confirm the creature as Bird.
Scientists improve Yamanaka’s invention to make iPSCs
Scientists at the Guangzhou Institutes of Biomedicine and Health, China have claimed that they have improved the efficiency of Shinya Yamanaka’s invention of producing induced Pluripotent Stem Cells (iPSC) which won Nobel Prize in Medicine.
What are iPSCs and how they are produced?
- iPSCs are body (somatic) cells which have been reprogrammed to function like embryonic stem cells, thereby sidestepping the controversial use of killing the embryos while harvesting the stem cells.
- This is done by introducing four regulatory factors (pieces of DNA) into the cells.
What are the four regulatory factors?
- The four regulatory factors which are also called Yamanaka’s factors are Oct4, Klf4, c-Myc and Sox2.
- These factors when when introduced in somatic cells activate or repress target genes. Expressed together they can, at low- frequency, convert cells to a relatively stable state of gene-expression similar to that seen in embryonic stem cells.
What is the problem with Yamanaka’s method?
- The challenge is the success rate of conversion of somatic cells into iPSCs which is just 0.01%.
What is the current finding?
- As per the latest studies, it has been found that the same Yamanaka’s factors when introduced in a specific sequence and timing enhances the efficiency of formation of iPSCs.
What is the importance of research on stem cells?
- The fundamental importance lies in understanding how humans develop and in understanding and treatment of disease and in regeneration.