THE HIDDEN RIVER

The worlds largest underground 'ocean'- a water body about the size of the artic ocean and located 700-1400 km below the ground and extending from Indonesia to the northern tip of Russia-has found its match. Scientists have discovered in Brazil the longest underground river-running for a length of 6000 km at a depth of nearly 4 km. It flows all the way from the andean foothills to the Atlantic coast in a nearly west-to-east direction like the mighty Amazon river. The river 'HAMZA' named after the discoverer, an indian born scientist Valiya mannathal Hamza who is working with the Nationa Observatory at Rio, makes it the first and geologically unusual instance of a twin-river system flowing at different levels of earths crust in Brazil. Unlike thn Hamza, the 153 km long underground river in Mexico's Yucatan peninsula and the 8.2 km long Cabayugan River in the puerto princesa subterranean river National park in the philippines have come into being thanks to the karst topography. Water in these places drills its way downward by dissolving the carbonate rock to form an extensive underground river system.

THINNESS LIES IN OUR GENES, FINDS A NEW STUDY

A study that examined DNA of 95,000 people shows that individuals that stay extremely thin all their lives might have extra copies of genes on chromosome 16. This genitic condition seen in one in 2000 people makes men 23 times more likely to be very skinny. "The genome is full of holes where genes are lost, and in other places. We have extra copies of genes. In many cases, duplications and deletions have no effect, but occasionaly they can lead to disease," says professor philippe froguel from imperial college london, lead author of study. Half of the children found to have this duplication were diagnosed with reduced appetites indicating that unwillingness to eat might be "genetically driven". A quarter of people with the duplication have microcephaly, a condition in which the head and brain are abnormally small, which is associated with neurological defects and shorter life expectancy. The same gene when missing a copy, was found to greatly increase the chance of obesity. "It's also the first example of deletion and a duplication of one part of genome having opposite effects. At the moment we don't know anything about the genes in this region. If we can work out why gene duplication in this region causes thinness, it might throw up new potential treatments for obesity and appetite disorders. We now plan to sequence these genes and find out what they do, so we can get an idea of which ones are involved in regulating appetite," says professor Froguel.