July 2014

Kiran Musunuru Vaccination against heart attacks: Harvard Stem Cell Institute (HSCI) scientists collaborating with researchers at the University of Pennsylvania have developed a "genome-editing" approach for permanently reducing cholesterol levels in mice through a single injection, a development that could reduce the risk of heart attacks in humans by 40 to 90 percent. Read more ....

Electric eel 'Shocking' truth: Scientists have found how the electric fish evolved its jolt. Writing in the journal Science, a team of researchers led by Michael Sussman of the University of Wisconsin-Madison, Harold Zakon of the University of Texas at Austin and Manoj Samanta of the Systemix Institute in Redmond, Washington identifies the regulatory molecules involved in the genetic and developmental pathways that electric fish have used to convert a simple muscle into an organ capable of generating a potent electrical field. Read more ....

Football Football physics: It happens every four years: The World Cup begins and some of the world's most skilled players carefully line up free kicks, take aim - and shoot way over the goal. The players are all trying to bend the ball into a top corner of the goal, often over a wall of defensive players and away from the reach of a lunging goalkeeper. Yet when such shots go awry in the World Cup, a blame game usually sets in. Players, fans, and pundits all suggest that the new official tournament ball, introduced every four years, is the cause. Read more .....

Penguins Warming and penguins: A study of how penguin populations have changed over the last 30,000 years has shown that between the last ice age and up to around 1,000 years ago penguin populations benefitted from climate warming and retreating ice. This suggests that recent declines in penguins may be because ice is now retreating too far or too fast. Read more ....

Football Splendid kick-off: On June 12, during the opening of the FIFA 2014 World Cup in Brazil, a paralyzed person wearing a brain-controlled robotic exoskeleton made the first kick of the football championship. For those who were watching the opening ceremony on television sets, it was a fleeting glimpse. Read more ....

Rise and fall of prehistoric penguin populations charted


(Photo credit: University of Southampton)

A study of how penguin populations have changed over the last 30,000 years has shown that between the last ice age and up to around 1,000 years ago penguin populations benefitted from climate warming and retreating ice. This suggests that recent declines in penguins may be because ice is now retreating too far or too fast.

An international team, led by scientists from the Universities of Southampton and Oxford, has used a genetic technique to estimate when current genetic diversity arose in penguins and to recreate past population sizes. Looking at the 30,000 years before human activity impacted the climate, as Antarctica gradually warmed, they found that three species of penguin; Chinstrap, Adelie and southern populations of Gentoo penguins increased in numbers. In contrast, Gentoo penguins on the Falkland Islands were relatively stable, as they were not affected by large changes in ice extent.

A report of the research is published in the journal Scientific Reports. Lead author of the paper, Gemma Clucas, from Ocean and Earth Sciences at the University of Southampton comments: "Whereas we typically think of penguins as relying on ice, this research shows that during the last ice age there was probably too much ice around Antarctica to support the large populations we see today. The penguins we studied need ice-free ground to breed on and they need to be able to access the ocean to feed. The extensive ice-sheets and sea ice around Antarctica would have made it inhospitable for them.

"What is particularly interesting is that after the ice age, all of these penguin populations were climate change 'winners', that is to say the warming climate allowed them to expand and increase in number. However, this is not the pattern we're seeing today. Adelie and Chinstrap penguins appear to be declining due to climate change around the Antarctic Peninsula, so they've become 'losers'. Only the Gentoo penguin has continued to be a 'winner' and is expanding its range southward.

Dr Tom Hart of the University of Oxford's Department of Zoology, an author of the paper, continues: "We are not saying that today's warming climate is good for penguins, in fact the current decline of some penguin species suggests that the warming climate has gone too far for most penguins.

"What we have found is that over the last 30,000 years different penguin species have responded very differently to a gradually warming world, not something we might expect given the damage current rapid warming seems to be doing to penguins' prospects."

To estimate changes in penguin genetic diversity, the researchers collected feathers and blood samples from 537 penguins in colonies around the Antarctic Peninsula. The scientists then sequenced a region of mitochondrial DNA that evolves relatively quickly. Using the rate of mutation of this region of DNA as a calibration point, the researchers were able to chart how the size of these populations has varied over time. The team working on the project included scientists from the British Antarctic Survey and also US scientists from Oceanites Inc, Woods Hole Oceanographic Institution, and the University of North Carolina, Wilmington.

"During the last ice age Antarctica was encircled by 100 per cent more winter sea ice than today," says Dr Tom Hart. "As ice retreated, these penguins had access to more breeding sites and more open ocean to feed."

Gemma Clucas, who is based at the National Oceanography Centre, Southampton, says: "Despite historic warming clearly opening up new opportunities for penguins, we should not assume that current rapid warming caused by human activity is good for penguins as a whole. Evidence from other studies shows that climate change today is creating lots of losers and few winners -- with chinstrap and Adelie populations around the Antarctic Peninsula declining fast. This is probably as a result of reductions in sea ice causing stocks of the krill they feed on to shrink, whilst populations of Gentoo penguins, which don't rely on krill as much, grow and expand."

Gentoo, chinstrap and Adelie penguins are all closely related to one another, being the only living members of the Pygoscelis genus. Adelie penguins diverged from the ancestors of gentoos and chinstraps 19 million years ago, while gentoos and chinstraps diverged 14 million years ago.

Gentoo penguins are the third largest of the penguins overall, and the biggest of the Pygoscelis penguins weighing in at 5 - 8 kilograms. There are estimated to be 387,000 breeding pairs and the global population appears to have increased over the last 20-30 years. Chinstrap penguins are the smallest of the Pygoscelis penguins, weighing from 3.5 - 5.5 kilograms. They breed further south than gentoo penguins and the global population is in decline due to declines of their primary food source, Antarctic krill. Population estimates are uncertain, but there are thought to be around 5 - 7 million pairs. Adelie penguins are slightly larger than chinstrap penguins weighing 3.7-6 kilograms. They breed the furthest south of the Pygoscelis penguins and their global population, which is estimated to be least 2-3 million breeding pairs, is thought to be stable, although trends vary regionally. In the Antarctic Peninsula region, they are declining rapidly as sea ice declines. They feed mainly on Antarctic krill.

(Source: University of Southampton news release)

Some useful links for
your career:

  • Union Public Service Commission - www.upsc.gov.in
  • IIT-Kharagpur - www.iitkgp.ac.in
  • Indian Statistical Institute - www.isical.ac.in
  • Indian Institute of Technology Madras - www.iitm.ac.in
  • Indian Institute of Management, Ahmedabad - www.iimahd.ernet.in
  • Indian Institute of Mass Commission - www.iimc.nic.in
  • IIT Bombay - www.iitb.ac.in
  • Indian School of Mines, Dhanbad - www.ismdhanbad.ac.in
  • Birla Institute of Technology, Ranchi - www.bitmesra.ac.in
  • Central Institute of Fisheries Nautical and Engineering Training - www.cifnet.nic.in
  • Indian Institute of Information Technology, Allahabad (Deemed University) - www.iiita.ac.in
  • Central Marine Fisheries Research Institute, Kochi - www.cmfri.com
  • Tata Institute of Social Sciences, Mumbai - www.tiss.edu

DISCLAIMER: The contents of this website are for informational purposes only. Although due care is taken, the correctness and accuracy cannot be guaranteed. The science and medical research articles are for informational purposes only, aimed at kindling an interest in science. They are not intended to provide any kind of advice.