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Comment by Dr. Krishna Kumari Challa on January 29, 2015 at 7:16am

Climate, vocal folds, and tonal languages: Connecting the physiological and geographic dots
http://www.pnas.org/content/early/2015/01/14/1417413112.abstract
The sound systems of human languages are not generally thought to be ecologically adaptive. We offer the most extensive evidence to date that such systems are in fact adaptive and can be influenced, at least in some respects, by climatic factors. Based on a survey of laryngology data demonstrating the deleterious effects of aridity on vocal cord movement, we predict that complex tone patterns should be relatively unlikely to evolve in arid climates. This prediction is supported by careful statistical sampling of climatic and phonological data pertaining to over half of the world’s languages. We conclude that human sound systems, like those of some other species, are influenced by environmental variables.
Extensive research on human physiology suggests that really dry air makes it hard for us to use our vocal cords very precisely.
Dry-throat-phenomenon in regards to complex tonal languages, like Cantonese <>, where various combinations of rising and falling tones can actually change the meaning of a word—as opposed to non-tonal languages, like English or Italian.
By mapping the distribution of more than 3,700 tonal and non-tonal languages, Everett and his colleagues found that tonal languages tend to cluster in warm, humid areas. And they're 10 times less prevalent in dry, sub-freezing climes, like Siberia, compared with non-tonal languages.
According to the researchers, language evolves in relation to where it’s spoken. It is not impervious to the effects of environment. Just as ecologies impact human behavior and the adaptive processes of human cultures in myriad ways, they seem to also influence the ways in which languages develop.

Comment by Dr. Krishna Kumari Challa on January 28, 2015 at 9:32am

Immune response: new light
Recognition of rare “foreign” peptides by the alpha-beta T-cell receptor (TCR) on T lymphocytes is critical for the adaptive immune response that protects our bodies. T cell motions during immune surveillance generate forces that are detected by the mechanosensing action of the TCR.

Using single-molecule and single-cell optical tweezer assays, Matthew Lang, Ph.D., and colleagues at Vanderbilt and at the Dana-Farber Cancer Institute in Boston demonstrate that the TCR uses force to enhance binding to foreign peptides and transitions to an extended conformation to release. They found that another part of the TCR complex controls the bond strength and extension transition in this “catch-and-release” model for TCR function.

The findings, reported this week in the Proceedings of the National Academy of Sciences, explain how T-cell receptors are able to seek out and bind to rare foreign peptides among many irrelevant interactions, all with low apparent binding affinity. The research sheds light on how T cells recognize their targets and on strategies for immunotherapies.

Force-dependent transition in the T-cell receptor β-subunit allosterically regulates peptide discrimination and pMHC bond lifetime. Dibyendu Kumar Das et al. PNAS, 2015.

Force-dependent transition in the T-cell receptor β-subunit allosterically regulates peptide discrimination and pMHC bond lifetime. Dibyendu Kumar Das et al. PNAS, 2015. doi:10.1073/pnas.1424829112

Comment by Dr. Krishna Kumari Challa on January 28, 2015 at 9:29am

Beating the clock: Researchers develop new treatment for rabies
Successfully treating rabies can be a race against the clock. Those who suffer a bite from a rabid animal have a brief window of time to seek medical help before the virus takes root in the central nervous system, at which point the disease is almost invariably fatal.

Now, researchers at the University of Georgia have successfully tested a new treatment on mice that cures the disease even after the virus has spread to the brain. They published their findings recently in the Journal of Virology.

"Basically, the best way to deal with rabies right now is simple: Don't get rabies," said study co-author Biao He, a professor of infectious diseases in the UGA College of Veterinary Medicine. "We have vaccines that can prevent the disease, and we use the same vaccine as a kind of treatment after a bite, but it only works if the virus hasn't progressed too far.

"Our team has developed a new vaccine that rescues mice much longer after infection than what was traditionally thought possible."

In their mouse experiments, the animals were exposed to a strain of the rabies virus that generally reaches the brain of infected mice within three days. By day six, mice begin to exhibit the telltale physical symptoms that indicate the infection has become fatal.

However, 50 percent of mice treated with the new vaccine were saved, even after the onset of physical symptoms on day six.

"This is the most effective treatment that has reported in the scientific literature till date"
The researchers developed their vaccine by inserting a protein from the rabies virus into another virus known as parainfluenza virus 5, or PIV5, which is thought to contribute to upper respiratory infections in dogs but is completely harmless to humans.

PIV5 acts as a delivery vehicle that carries the rabies protein to the immune system so it may create the antibodies necessary to fight off the virus.
Apart from being very effective in saving the infected mice, the researchers emphasized that their vaccine is much safer when compared to the best current treatment in mice, which uses a weakened version of the rabies virus.
http://jvi.asm.org/content/early/2014/12/26/JVI.03656-14.full.pdf+html
Parainfluenza virus 5 expressing the G protein of rabies virus protected mice after rabies virus infection J. Virol. JVI.03656-14

Comment by Dr. Krishna Kumari Challa on January 28, 2015 at 9:23am

Cancer uses a little-understood element of cell signaling to hijack the communication process and spread, according to Rice University researchers.

A new computational study by researchers at the Rice-based Center for Theoretical Biological Physics shows how cancer cells take advantage of the system by which cells communicate with their neighbors as they pass messages to “be like me” or “be not like me.”

Led by Rice biophysicists Eshel Ben-Jacob and José Onuchic, the researchers decode how cancer uses a cell-cell interaction mechanism known as notch signaling to promote metastasis. This mechanism plays a crucial role in embryonic development and wound healing and is activated when a delta or jagged ligand of one cell interacts with the notch receptor on an adjacent one.
Cancer cells have the ability to hijack the notch-signaling mechanism that cells use to communicate with each other, especially when “jagged” ligands allow for two-way signaling, according to Rice University scientists. Signals pass between cells when delta or jagged ligands on one bind to external notch proteins on the other.
http://news.rice.edu/2015/01/26/how-cancer-turns-good-cells-to-the-...

At the heart of our new understanding is that the primary agents of metastasis are clusters of hybrid epithelial (nonmobile) and mesenchymal (migrating) cells,” Ben-Jacob said. “These, and not the fully mesenchymal cells, are the ‘bad actors’ of cancer progression that pose the highest risk. By acting together, these hybrid cancer cells have a better chance to evade the immune system during migration and can better survive while circulating in blood vessels.”

The multifaceted mechanism by which notch-delta-jagged signaling promotes cancer progression has been a mystery until now, Ben-Jacob said, but recent experimental studies have revealed the jagged ligand plays a critical role in tumor progression.

The new study provides a fresh theoretical framework for scientists who study the fates of cells. It shows the presence of jagged ligands can give rise to sender/receiver hybrid cells that send a signal — “be like me” — that is useful for embryonic development and healing, but can also be hijacked by cancer cells.

Comment by Dr. Krishna Kumari Challa on January 27, 2015 at 9:31am

The 50 most critical scientific & technological breakthroughs required for sustainable global development
https://www.ligtt.org/50-breakthroughs

Comment by Dr. Krishna Kumari Challa on January 27, 2015 at 7:01am

Why light rain brings sweet aromas:

MIT scientists have identified the mechanism that releases an earthy smell in the air after a light rain.

Using high-speed cameras, the researchers at the Massachusetts Institute of Technology observed that when a raindrop hits a porous surface, it traps tiny air bubbles at the point of contact.

As in a glass of champagne, the bubbles then shoot upward, ultimately bursting from the drop in a fizz of aerosols.

The team was also able to predict the amount of aerosols released, based on the velocity of the raindrop and the permeability of the contact surface.

The researchers suspect that in natural environments, aerosols may carry aromatic elements, along with bacteria and viruses stored in soil. These aerosols may be released during light or moderate rainfall, and then spread via gusts of wind.

This can help in identifying how soil-borne diseases spread.

Comment by Dr. Krishna Kumari Challa on January 24, 2015 at 8:32am

The myths about glass was shattered by scientists:
There was a myth that glass not being a real solid. Old church windows, the story went, had become thicker on the bottom over time, as the glass, though appearing solid, continued to very, very slowly flow with gravity. It turns out the variation in the thickness of old windows was due to a quirk of how large panes were made in medieval times, and glass is, in fact, a true solid, although it takes a little time to get all the way there.

During solidification, the molecules in most substances settle into a crystalline structure. But under a microscope, scientists noticed that glass, when cooling from a malleable, heated state, never quite achieves this crystallization, and seems to keep flowing, albeit extremely slowly. For years, this puzzled researchers, and glass was referred to as an “amorphous solid.” While the “glass-never-truly-solidifies” concept has apparently been challenged for decades, a paper just published in Nature Communications journal combined research from the University of Bristol and Kyoto University to finally settle the issue.
Though under  a microscope, glass appears to keep moving even after it cools and feels solid to the touch, the atoms are actually very slowly arranging themselves into geometric shapes, like icosahedra, increasing the solid regions of the material over time.
http://www.nature.com/ncomms/2015/150122/ncomms7089/full/ncomms7089...

Comment by Dr. Krishna Kumari Challa on January 22, 2015 at 9:48am

In a Cell Perspectives paper published in December, Deborah Muoio, PhD, a Duke University researcher investigating the impact of diet and exercise on metabolic health, explains how overeating can be detrimental to our health by contributing to cellular traffic jams—and ultimately to obesity and metabolic disease.
http://www.sciencedirect.com/science/article/pii/S0092867414015116

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.

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