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Comment by Dr. Krishna Kumari Challa on December 30, 2016 at 9:55am

Vera Rubin Didn't Discover Dark Matter

https://blogs.scientificamerican.com/guest-blog/vera-rubin-didnt-di...

Comment by Dr. Krishna Kumari Challa on December 29, 2016 at 10:32am

Scientists face Intimidation and death threats in the US!

Troubling Signs for Science under Trump

The next four years are looking grim for science in America

https://blogs.scientificamerican.com/rosetta-stones/troubling-signs...

Comment by Dr. Krishna Kumari Challa on December 28, 2016 at 11:31am

The Postmortem Skin Microbiome to Estimate the Postmortem Interval

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.01...

Necrobiome. Heard about it before? It is the microbiological ecology of dead bodies. The genetic signatures of that microbial community as it waned and waxed after death can be used to build an algorithm that could pinpoint a corpse's time of death, to an accuracy of just two summertime days and can be used in forensic science.

Comment by Dr. Krishna Kumari Challa on December 28, 2016 at 11:18am

China's pollution is causing millions of premature deaths.

A team of researchers led by Professor Zhu Tong from Peking university used PM2.5 data from over 500 ground observation stations in China, re-analyzing them using a newly developed integrated exposure-response (IER) model to estimate the risk of premature death due to exposure to PM2.5. They found that 84 percent of China’s population live in areas where the yearly average PM2.5 exceeded 35 micrograms per cubic meter, the upper limit set in ambient air quality standards by the World Health Organization. Their model predicted that this exposure to high PM2.5 levels resulted in 1.37 million premature deaths, of which 50 percent, 28 percent and 12 percent were due to cerebrovascular disease, ischemic heart disease and chronic obstructive pulmonary disease respectively. The study also points out that if the concentration of PM2.5 meets the WHO standards, the risk of premature death can decrease by 39 percent, 23 percent and 66 percent respectively, revealing the non-linear relationship between the decrease of PM2.5 and the improvement of different health conditions. 

Estimating adult mortality attributable to PM_2.5 exposure in China with assimilated PM_2.5 concentrations based on a ground monitoring network

http://www.sciencedirect.com/science/article/pii/S0048969716310956

Comment by Dr. Krishna Kumari Challa on December 20, 2016 at 11:31am

Earth’s surface is shattered by roads into over 600,000 fragments – more than half of which are smaller that one square kilometre – severely reducing the ability of ecosystems to function effectively, a new study has found.

Roads have made it possible for humans to access almost every region but this comes at a very high cost ecologically to the planet’s natural world. Despite substantial efforts to conserve the world’s natural heritage, large tracts of valuable roadless areas remain unprotected, researchers said.

The researchers from the Eberswalde University for Sustainable Development in Germany used a dataset of 36 million kilometres of roads across the landscapes of the earth. They are dividing them into more than 600,000 pieces that are not directly affected by roads.

Of these remaining roadless areas only seven per cent are larger than 100 square kilometres. The largest tracts are to be found in the tundra and the boreal forests of North America and Eurasia, as well as some tropical areas of Africa, South America and Southeast Asia. Only nine per cent of these areas undisturbed by roads are protected.

Roads introduce many problems to nature. For instance, they interrupt gene flow in animal populations,facilitate the spread of pests and diseases, and increase soil erosion and the contamination of rivers and wetlands.

Then there is the free movement of people made possible by road development in previously remote areas, which has opened these areas up to severe problems such as illegal logging, poaching and deforestation.

Most importantly, roads trigger the construction of further roads and the subsequent conversion of natural landscapes, a phenomenon the study labels “contagious development.”

“Our global map provides guidance on the location of the most valuable roadless areas,” said Pierre Ibisch, from the Eberswalde University. In many cases they represent remaining tracks of extensive functional ecosystems, and are of key significance to ecological processes, such as regulating the hydrological cycle and the climate,” said Ibisch.

The researchers used a large data base generated through crowd-sourcing platform to produce a global map for roadless.

All roads affect the environment in some shape or form including timber extraction tracks and minor dirt roads, and the impacts can be felt far beyond the road edge.

Comment by Dr. Krishna Kumari Challa on December 17, 2016 at 8:33am

Comment by Dr. Krishna Kumari Challa on December 17, 2016 at 6:51am

A “crater” in Antarctica once thought to be the work of a meteorite impact is actually the result of ice melt, new research finds.

The hole, which is in the Roi Baudouin ice shelf in East Antarctica, is a collapsed lake — a cavity formed when a lake of meltwater drained — with a “moulin,” a nearly vertical drainage passage through the ice, beneath it, researchers found on a field trip to the area in January 2016.

Combining their fieldwork with satellite data and climate modeling, the researchers found that East Antarctica is more vulnerable to melt than was previously realized. Warm winds to the region blow away the snow cover, which darkens the surface of the ice, the team reported Dec. 12 in the journal Nature Climate Change. Darker surfaces absorb more heat from the sun than lighter surfaces, so they are more prone to melt. These floating ice sheets don’t contribute much to sea level rise ­— as they’re already in the ocean — but they provide an important backstop against the flowing of land-based ice from continental Antarctica into the ocean.

Comment by Dr. Krishna Kumari Challa on December 15, 2016 at 7:38am

A funny and scientific way of explaining Father Christmas:

The mystery of how Father Christmas can deliver presents to 700 million children in one night, fit down the chimney and arrive without being seen or heard has been explained in a scientific way by a physicist at the University of Exeter.

Santa and his reindeer zoom around the world at such speed that - according to relativity theory - they would shrink, enabling Father Christmas and a huge sack of presents to fit down chimneys.

Dr Katy Sheen, a physicist in the Geography department at the University of Exeter, has also found a scientific explanation for why Santa is not heard arriving by children, and why they rarely catch a glimpse of him on Christmas eve.

Santa's stealth delivery is partly explained by special relativity theory devised by Albert Einstein, whom Dr Sheen thinks bares a passing resemblance to Santa.

Relativity theory explains how Father Christmas can fit down the chimney. At the speeds he needs to travel to deliver presents to every child, Father Christmas shrinks - or gets thinner - in the direction he is travelling. And he has to be careful not to stop for a mince pie in a chimney, or he could grow back to full size!

Relativity also explains why Father Christmas appears not to have aged throughout the ages, because relativity can slow down clocks.

The physicist has calculated that Santa and his reindeer would have to travel at about 10 million kilometres per hour to deliver presents to every child expected to celebrate Christmas in 31 hours (taking into account world time zones).

If millions of children have been good, and deserve bigger stockings, he may need to travel even faster. Such speed would make him change from red to green and, at greater speeds, he would disappear! Children would not be able to recognise him as he would appear as a rainbow-coloured blur, eventually disappearing to the human eye.

Travelling at more than 200,000 times faster than Usain Bolt, the world's fastest man, the laws of physics explain why Father Christmas is rarely seen by children while delivering presents.

The Doppler effect would make Santa change colour because the light waves he releases would get squashed at such a high speed.

The Doppler effect also explains why children cannot hear Father Christmas arrive. As Santa and his sleigh approach, the sound of bells and his deep 'ho, ho, ho' would get higher and higher (like when an ambulance siren whizzes by) and then become completely silent, because he would move beyond human hearing range. Even the sound of Santa urging on Rudolph would become unrecognisable, and then inaudible to the human ear.

If children hear a bang on Christmas night, it may not be the sound of Santa dropping his presents, landing on their roof in his sleigh, or sliding down the chimney with a plop. Santa's reindeer could have broken the speed of sound, resulting in a 'sonic boom.'

Dr Sheen, a physicist working in the University of Exeter's Geography department, is not planning to present her research to a peer-reviewed journal (it's prepared with the festive spirit in mind), and has done the calculations in her own time to interest children in science and physics.

-Eureka Alert

Comment by Dr. Krishna Kumari Challa on December 13, 2016 at 10:41am

Researchers from Egypt and Saudi Arabia have developed a simple way to manufacture an eco-friendly and affordable membrane that can efficiently adsorb oils spills from sea or waste water.

The membrane can recover quickly and easily for reuse — it can be applied at least 10 times with the same efficiency, according to a study published in Marine Pollution Bulletin.

The nanostructured polymer blend adsorbs oil and can be reused at least 10 times.It is made from natural materials friendly to the environment and aquatic organisms. Its capacity to work on a large scale, with oil spills at sea, has yet to be tested.

the study published last September tested blends of nanoscale polyvinyl alcohol polymers, considered to be among the most dissolvable and non-toxic biopolymers. They can also be manufactured relatively cheaply from biodegradable and biocompatible polymers.

Comment by Dr. Krishna Kumari Challa on December 12, 2016 at 8:43am

Effects of c- section births on evolution

Caesarean section (or C-section) deliveries can save lives when babies are too large to be born naturally - or if there are other health complications - but they also appear to be affecting how humans are evolving, scientists report.

In the past, larger babies and mothers with narrow pelvis sizes might both have died in labour.  Thanks to C-sections, that's now a lot less likely, but it also means that those 'at risk' genes from mothers with narrow pelvises are being carried into future generations.

Cases where a baby can't fit through the birth canal have increased from 30 in 1,000 births in the 1960s to 36 in 1,000 today because of this C-section effect, according to estimates from researchers at the University of Vienna in Austria.  That's a significant shift in just half a century.

"Without modern medical intervention, such problems often were lethal and this is, from an evolutionary perspective, selection.

The team used a mathematical model based on obstructed child birth data to reach their estimates.

More detailed studies would be required to actually confirm the link between C-sections and evolution, as all we have now is a hypothesis based on the birth data. But Mitteroecker and his colleagues say it's important to consider the effect the rise in these procedures is having.

There are already a few conflicting evolutionary forces at work here, scientists think, in what's known as the obstetrical dilemma.

The 'dilemma' is that the larger a baby is when it's born, the more likely its chances of survival. At the same time, women have evolved with smaller pelvic sizes to aid upright walking and to limit the chances of premature births.

Both evolutionary pressures are working to try and keep babies healthy... but they're also working against each other.

"One side of this selective force - namely the trend towards smaller babies - has vanished due to caesarean sections.

This evolutionary trend will continue but perhaps only slightly and slowly.

Cliff-edge model of obstetric selection in humans

http://www.pnas.org/content/early/2016/11/29/1612410113

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