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Comment by Dr. Krishna Kumari Challa on November 28, 2014 at 8:28am

Natural shield 11,000 km above Earth stops radiation
Researchers from Massachusetts Institute of Technology ( MIT) and University of Colorado in Boulder have discovered an invisible shield some 11,000 kms above Earth that works against the harmful radiation belt.
High above Earth's atmosphere, electrons whiz past at close to the speed of light.

Such ultra-relativistic electrons, which make up the outer band of the Van Allen radiation belt, can streak around the planet in a mere five minutes - bombarding anything in their path.
The Van Allen belts are a collection of charged particles - gathered in place by Earth's magnetic field.

Exposure to such high-energy radiation can wreak havoc on satellite electronics and pose serious health risks to astronauts. Rresearchers found no matter where these electrons are circling around the planet's equator, they can get no further than about 11,000 km from the Earth's surface - despite their intense energy. What is keeping this high-energy radiation at bay seems to be neither the Earth's magnetic field nor long-range radio waves but rather a phenomenon termed 'plasmaspheric hiss'.
The phenomenon is described as very low-frequency electromagnetic waves in the Earth's upper atmosphere that, when played through a speaker, resemble static or white noise.

The researchers believe that plasmaspheric hiss essentially deflects incoming electrons causing them to collide with neutral gas atoms in the Earth's upper atmosphere and ultimately disappear.
The paper on which this report is based was published in the journal Nature.

Comment by Dr. Krishna Kumari Challa on November 27, 2014 at 7:32am

Beetle behind breath test for bank notes
Simply breathing on money could soon reveal if it's the real deal or counterfeit thanks to a beetle-inspired ink that reversibly changes colour in response to humidity. The photonic crystal ink developed by Chinese researchers can produce unique colour changing patterns on surfaces with an inkjet printer system, which would be extremely hard for fraudsters to reproduce. The work also shows promise for other applications including displays and wearable sensors.

Ling Bai and Zhongze Gu and colleagues at Southeast University in Nanjing, China, have developed a photonic crystal ink that mimics the way Tmesisternus isabellae – a species of longhorn beetle – reversibly switches its color from gold to red according to the humidity in its environment.

This color shift is caused by the adsorption of water vapour in their hardened front wings, which alters the thickness and average refractive index of their multilayered scales. To emulate this, the team made their photonic crystal ink using mesoporous silica nanoparticles, which have a large surface area and strong vapour adsorption capabilities that can be precisely controlled.

Using the ink in an inkjet printer, the researchers produced complex patterns on rigid and flexible materials and showed that their colour can be reversibly and precisely controlled – shifting from green to red or yellow for example – in response to nitrogen and ethanol vapours. They even saw patterns change colour simply in response to breathing on them.

http://www.rsc.org/chemistryworld/2014/11/beetle-behind-breath-test...

Comment by Dr. Krishna Kumari Challa on November 27, 2014 at 6:47am

India is home to one of the highest proportions of threatened species in the world

http://www.livemint.com/Politics/V5SjMWmLe30Z1c9gr1iqxK/Indias-wild...

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Comment by Dr. Krishna Kumari Challa on November 27, 2014 at 6:36am

Asteroid impacts on Earth may give rise to rare, structurally bizarre diamonds on our planet, a new study suggests.

Scientists have settled a longstanding controversy over a purported rare form of diamond called lonsdaleite - formed by impact shock, but which lacks the three-dimensional regularity of ordinary diamond
A group of scientists has now shown that what has been called lonsdaleite is in fact a structurally disordered form of ordinary diamond.

"So-called lonsdaleite is actually the long-familiar cubic form of diamond, but it's full of defects," said Peter Nemeth, a former Arizona State University (ASU) visiting researcher.

These can occur, he said, due to shock metamorphism, plastic deformation or unequilibrated crystal growth

Scientists said that a large meteorite, called Canyon Diablo after the crater it formed on impact in northern Arizona, contained a new form of diamond with a hexagonal structure.

They described it as an impact-related mineral and called it lonsdaleite, after Dame Kathleen Lonsdale, a famous crystallographer.

Since then, "lonsdaleite" has been widely used by scientists as an indicator of ancient asteroidal impacts on Earth, including those linked to mass extinctions.

In addition, it has been thought to have mechanical properties superior to ordinary diamond, giving it high potential industrial significance.

All this focused much interest on the mineral, although pure crystals of it, even tiny ones, have never been found or synthesised.
Scientists re-examined Canyon Diablo diamonds and investigated laboratory samples prepared under conditions in which lonsdaleite has been reported.

Using the advanced electron microscopes, the team found, both in the Canyon Diablo and the synthetic samples, new types of diamond twins and nanometre-scale structural complexity. These give rise to features attributed to lonsdaleite

"Most crystals have regular repeating structures, much like the bricks in a well-built wall," said Peter Buseck, from the University of Bayreuth in Germany.

However, interruptions can occur in the regularity, and these are called defects.

"Defects are intermixed with the normal diamond structure, just as if the wall had an occasional half-brick or longer brick or row of bricks that's slightly displaced to one side or another," said Buseck.

The outcome of the new work is that so-called lonsdaleite is the same as the regular cubic form of diamond, but it has been subjected to shock or pressure that caused defects within the crystal structure.

The study was published in the journal Nature Communications.

Comment by Dr. Krishna Kumari Challa on November 26, 2014 at 9:20am

Hormone estrogen may shield the brain after an injury
Inflammation goes down when the sex hormone increases around an injury
Estrogen can protect the brain from harmful inflammation following traumatic injury, a new study in zebra finches suggests. Boosting levels of the sex hormone in the brain might help prevent the cell loss that occurs following damage from injuries such as stroke.

Estrogen levels quadrupled around the damaged area in both male and female zebra finches after researchers gave them experimental brain injuries, Colin Saldanha and colleagues at American University in Washington, D.C., reported November 17 at the annual meeting of the Society for Neuroscience. When the scientists prevented finch brains from making estrogen, inflammatory proteins at damaged sites increased.

The helpful estrogen didn’t come from gonads. It’s made within the brain by support cells called astrocytes close to the injury.

Injury inflames the brain. Initially, this inflammation recruits helpful cells to the damaged area and aids in recovery. But the long-term presence of inflammatory proteins can cause harm, killing off brain cells and reducing functions such as movement and memory. The researchers hope that by understanding how estrogen reduces inflammatory proteins, therapies might boost this natural estrogen production to keep harmful inflammation at bay.
- http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=6a2113dc...

Comment by Dr. Krishna Kumari Challa on November 26, 2014 at 8:03am

New light on heart disease:
Scientists now think that inflammation is a key factor in heart disease.

The older thinking was that plaque in coronary arteries caused heart attacks. Now the thinking is that it’s also due to some living tissue under plague that gets inflamed and that disrupts the plaque. We already knew statins ameliorate heart disease, and always thought it was through lipids, but here’s a new pathway.
And Statins May Protect People from Air Pollution
Statins, prescribed to lower cholesterol and reduce risks of heart attacks and strokes, seem to diminish inflammation that occurs after people breathe airborne particles.
http://www.environmentalhealthnews.org/ehs/news/2014/nov/statins-an...
The studies on these are still underway and we will report them when the results are published.

Comment by Dr. Krishna Kumari Challa on November 26, 2014 at 7:32am

How DNA Damage Leads To Cancer
Scientists have identified the protein Rad54B as a key regulator of genomic stability, making it a potential target for cancer therapy.
http://www.nature.com/ncomms/2014/141111/ncomms6426/full/ncomms6426...

Comment by Dr. Krishna Kumari Challa on November 26, 2014 at 7:19am

Horizontal gene transfer: Antibiotic genes spread far and wide
The genes responsible for antibiotics can spread between the three domains of life—Archaea, Bacteria and Eukaryotes.

The genes for proteins with antibacterial properties are capable of spreading across stunning evolutionary distances (Metcalf et al., 2014). Their results suggest that our search for new antibiotics needs to be broadened if we are to take full advantage of the variety of antibacterial compounds that exist in nature.
Genes are able to move between organisms in a process known as horizontal gene transfer. This happens most frequently between individuals of the same, or closely-related species (Andam and Gogarten 2011) and is thought to be responsible for the spread of antibiotic resistance genes between bacteria. However, genes can also occasionally move between distantly-related individuals, including from one domain of life, such as Bacteria, to either Archaea or Eukaryotes (Lundin et al., 2010). Whether a gene is successfully transferred depends on a number of constraints. For instance, if the organisms inhabit different environments, there are fewer opportunities to transfer genes. Once transferred, a gene may not be compatible with the recipient, or may not provide it with an advantage. Despite these constraints, some genes have spread, via horizontal transfer, to all three domains of life, and such transfer events may have been extensive during evolution .
http://elifesciences.org/content/3/e05244#sthash.ukduippX.dpuf

Comment by Dr. Krishna Kumari Challa on November 25, 2014 at 6:44am

Deceptive Practices in Drugs Research Could Become Harder
The proposed crack-down would close loopholes that allow researchers to hide negative findings and harmful side effects

US government cracks down on clinical-trials reporting

Proposed regulations would close loopholes that allow researchers to hide negative data.
http://www.nature.com/news/us-government-cracks-down-on-clinical-tr...

Comment by Dr. Krishna Kumari Challa on November 25, 2014 at 6:38am

Tufts Study Finds Big Rise In Cost Of Drug Development
Pharmaceuticals: Benchmark report sees the cost of bringing a drug to market approaching $3 billion
http://cen.acs.org/articles/92/web/2014/11/Tufts-Study-Finds-Big-Ri...

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