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Comment by Dr. Krishna Kumari Challa on January 21, 2015 at 2:06pm

Speed of light not so constant after all
Pulse structure can slow photons, even in a vacuum
Photons that travel in free space slower than the speed of light
That the speed of light in free space is constant is a cornerstone of modern physics. However, light beams have finite transverse size, which leads to a modification of their wavevectors resulting in a change to their phase and group velocities. We study the group velocity of single photons by measuring a change in their arrival time that results from changing the beam's transverse spatial structure. Using time-correlated photon pairs we show a reduction of the group velocity of photons in both a Bessel beam and photons in a focused Gaussian beam. In both cases, the delay is several microns over a propagation distance of the order of 1 m. Our work highlights that, even in free space, the invariance of the speed of light only applies to plane waves. Introducing spatial structure to an optical beam, even for a single photon, reduces the group velocity of the light by a readily measurable amount.
http://arxiv.org/abs/1411.3987

Comment by Dr. Krishna Kumari Challa on January 21, 2015 at 1:07pm

New light on tectonic plate movement:

A Yale University-led study may have solved one of the biggest mysteries in geology - why do tectonic plates beneath the Earth's surface sometimes move abruptly.

Traditionally, scientists believed that all tectonic plates are pulled by subducting slabs which result from the colder, top boundary layer of the Earth's rocky surface becoming heavy and sinking slowly into the deeper mantle.

Yet that process does not account for sudden plate shifts.

Such abrupt movement requires that slabs detach from their plates but doing this quickly is difficult since the slabs should be too cold and stiff to detach.

According to the Yale study, there are additional factors at work.

Thick crust from continents or oceanic plateaux is swept into the subduction zone, plugging it up and prompting the slab to break off.

The detachment process is then accelerated when mineral grains in the necking slab start to shrink, causing the slab to weaken rapidly.

The result is tectonic plates that abruptly shift horizontally or continents suddenly bobbing up.

"Understanding this helps us understand how the tectonic plates change through the Earth's history. It adds to our knowledge of the evolution of our planet, including its climate and biosphere," said Yale geophysicist David Bercovici.

The study was published in the journal Proceedings of the National Academy of Sciences.

Comment by Dr. Krishna Kumari Challa on January 20, 2015 at 9:06am

Promising antibiotic discovered in microbial ‘dark matter’

Potential drug kills pathogens such as MRSA — and was discovered by mining 'unculturable' bacteria.
http://www.nature.com/news/promising-antibiotic-discovered-in-micro...

Comment by Dr. Krishna Kumari Challa on January 20, 2015 at 8:54am

India launches “Pracheen Nek Puraskar,” an “Ancient Nobel Prize” for Ancient Indian Science!
Indian government has now launched Pracheen Nek Puraskar, an award to recognize the brilliance of ancient Indian minds.
http://www.fakingnews.firstpost.com/2015/01/india-launches-pracheen...

Comment by Dr. Krishna Kumari Challa on January 20, 2015 at 7:24am

'At least two more planets' beyond Pluto, scientists think
At least two as-yet undiscovered planets as big as Earth or larger may be hiding in the outer fringes of the Solar System, according to space scientists

The secret worlds are thought to exist beyond the orbits of Neptune, the furthest true planet from the Sun, and the even more distant tiny ''dwarf planet'' Pluto.

The evidence comes from observations of a belt of space rocks known as ''extreme trans-Neptunion objects'' (Etnos).

Orbiting the Sun beyond Neptune, Etnos should be distributed randomly with paths that have certain defined characteristics.

But a dozen of the bodies have completely unexpected orbital values consistent with them being influenced by the gravitational pull of something unseen.
According to the scientists, this excess of objects with unexpected orbital parameters makes them believe that some invisible forces are altering the distribution of the orbital elements of the Etno, and they consider that the most probable explanation is that other unknown planets exist beyond Neptune and Pluto.
The new research, published in the journal Monthly Notices of the Royal Astronomical Society Letters, is based on analysis of an effect called the ''Kozai mechanism'', by which a large body disturbs the orbit of a smaller and more distant object.

The scientists wrote: ''In this scenario, a population of stable asteroids may be shepherded by a distant, undiscovered planet larger than the Earth ... ''

Comment by Dr. Krishna Kumari Challa on January 18, 2015 at 7:15am

Iron overload disease causes rapid growth of potentially deadly bacteria
Every summer, the news reports on a bacterium called Vibrio vulnificus found in warm saltwater that causes people to get sick, or die, after they eat raw tainted shellfish or when an open wound comes in contact with seawater.

People with a weakened immune system, chronic liver disease or iron overload disease are most at risk for severe illness. Vibrio vulnificus infections in high-risk individuals are fatal 50 percent of the time.

Now, researchers at UCLA have figured out why those with iron overload disease are so vulnerable. People with the common genetic iron overload disease called hereditary hemochromatosis have a deficiency of the iron-regulating hormone hepcidin and thus develop excess iron in their blood and tissue, providing prime growth conditions for Vibrio vulnificus.

The study also found that minihepcidin, a medicinal form of the hormone hepcidin that lowers iron levels in blood, could cure the infection by restricting bacterial growth.

The early findings were reported online Jan. 14 in the journal Cell Host and Microbe.
http://www.cell.com/cell-host-microbe/abstract/S1931-3128%2814%2900...

Comment by Dr. Krishna Kumari Challa on January 16, 2015 at 6:17am

Comment by Dr. Krishna Kumari Challa on January 15, 2015 at 8:27am

Comment by Dr. Krishna Kumari Challa on January 15, 2015 at 8:27am

Global mobility: Science on the move

The big picture of global migration shows that scientists usually follow the research money — but culture can skew this pattern.

http://www.nature.com/news/global-mobility-science-on-the-move-1.11602

Comment by Dr. Krishna Kumari Challa on January 13, 2015 at 7:13am

Easter Island Extinction Blamed on Environment
Variation in Rapa Nui (Easter Island) land use indicates production and population peaks prior to European contact

Abstract

Many researchers believe that prehistoric Rapa Nui society collapsed because of centuries of unchecked population growth within a fragile environment. Recently, the notion of societal collapse has been questioned with the suggestion that extreme societal and demographic change occurred only after European contact in AD 1722. Establishing the veracity of demographic dynamics has been hindered by the lack of empirical evidence and the inability to establish a precise chronological framework. We use chronometric dates from hydrated obsidian artifacts recovered from habitation sites in regional study areas to evaluate regional land-use within Rapa Nui. The analysis suggests region-specific dynamics including precontact land use decline in some near-coastal and upland areas and postcontact increases and subsequent declines in other coastal locations. These temporal land-use patterns correlate with rainfall variation and soil quality, with poorer environmental locations declining earlier. This analysis confirms that the intensity of land use decreased substantially in some areas of the island before European contact.
http://www.pnas.org/content/early/2015/01/02/1420712112

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