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Comment by Dr. Krishna Kumari Challa on April 8, 2017 at 6:45am

Turbulence strong enough to injure airline passengers and crew could become twice as common because of climate change, a study has found.

Thousands of people are hurt during flights each year as turbulence causes aircraft to rise or fall rapidly without warning. Most cases are minor but there are hundreds of serious injuries and dozens of deaths, mainly on small planes.

Rising carbon dioxide emissions are increasing the temperature difference between bands of air at cruising altitude, according to research by the University of Reading. This strengthens the jet stream, the ribbon of strong winds which flows from west to east around the planet.

The acceleration of the jet stream is causing it to become less stable. Layers of air within it move at different speeds and this difference is increasing as the planet warms, producing more turbulence for aircraft.

The researchers found that the growth in the amount of CO2 in the atmosphere expected by 2050 could increase severe turbulence by at least 85 per cent.

During such severe turbulence, an aircraft’s altitude can deviate suddenly by around 100ft up or down, causing anyone unbuckled and any unsecured object to be thrown around the cabin.

The study, published in the journal Advances in Atmospheric Sciences, said that increased turbulence might not result in a rise in injuries if airlines became better at forecasting it and taking avoiding action.

Comment by Dr. Krishna Kumari Challa on April 7, 2017 at 7:13am

Chemical weapons - how they work - video

Comment by Dr. Krishna Kumari Challa on April 6, 2017 at 6:36am

A Graphene-Based Sieve That Turns Seawater Into Drinking Water

We need drinking water but with the ever shrinking drinkable water sources, we have to make do with saline water available abundantly in seas and oceans across the world. Scientists now have found a way to convert sea water to pure water.
The invention of a graphene-oxide membrane that sieves salt right out of seawater is unique.

At this stage, the technique is still limited to the lab, but it's a demonstration of how we could one day quickly and easily turn one of our most abundant resources, seawater, into one of our most scarce - clean drinking water.

The team, led by Rahul Nair from the University of Manchester in the UK, has shown that the sieve can efficiently filter out salts, and now the next step is to test this against existing desalination membranes.
Graphene-oxide membranes have long been considered a promising candidate for filtration and desalination, but although many teams have developed membranes that could sieve large particles out of water, getting rid of salt requires even smaller sieves that scientists have struggled to create.

One big issue is that, when graphene-oxide membranes are immersed in water, they swell up, allowing salt particles to flow through the engorged pores.

The Manchester team overcame this by building walls of epoxy resin on either side of the graphene oxide membrane, stopping it from swelling up in water.
This allowed them to precisely control the pore size in the membrane, creating holes tiny enough to filter out all common salts from seawater.

The key to this is the fact that when common salts are dissolved in water, they form a 'shell' of water molecules around themselves.

"Water molecules can go through individually, but sodium chloride cannot. It always needs the help of the water molecules," Nair said.

"The size of the shell of water around the salt is larger than the channel size, so it cannot go through."

Not only did this leave seawater fresh to drink, it also made the water molecules flow way faster through the membrane barrier, which is perfect for use in desalination.

"When the capillary size is around one nanometre, which is very close to the size of the water molecule, those molecules form a nice interconnected arrangement like a train," Nair explained .

"That makes the movement of water faster: if you push harder on one side, the molecules all move on the other side because of the hydrogen bonds between them. You can only get that situation if the channel size is very small."

Graphene oxide is also a lot easier and cheaper to make in the lab than single-layers of graphene, which means the technology will be affordable and easy to produce.
http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2017.2...

Comment by Dr. Krishna Kumari Challa on March 31, 2017 at 6:58am

Particles that cover the surface of Saturn's largest moon, Titan, are "electrically charged" and can cling together for months, scientists have found for the first time.

When the wind blows hard enough, Titan's non-silicate granules get kicked up and start to hop in a motion referred to as saltation. As they collide, they become frictionally charged, like a balloon rubbing against your hair, and clump together in a way not observed for sand dune grains on Earth - they become resistant to further motion. They maintain that charge for days or months at a time and attach to other hydrocarbon substances, much like packing peanuts used in shipping boxes here on Earth.

"If you grabbed piles of grains and built a sand castle on Titan, it would perhaps stay together for weeks due to their electrostatic properties," said Josef Dufek, from Georgia Institute of Technology in the US.

"Any spacecraft that lands in regions of granular material on Titan is going to have a tough time staying clean. Think of putting a cat in a box of packing peanuts," Dufek. The electrification findings may help explain an odd phenomenon. Prevailing winds on Titan blow from east to west across the moon's surface, but sandy dunes nearly 300 feet tall seem to form in the opposite direction.

"These electrostatic forces increase frictional thresholds," said Josh Mendez Harper, a doctoral student at Georgia Tech. "This makes the grains so sticky and cohesive that only heavy winds can move them. The prevailing winds aren't strong enough to shape the dunes," said Mendez Harper.

The findings have just been published in the journal Nature Geoscience.

Comment by Dr. Krishna Kumari Challa on March 15, 2017 at 8:20am

Good news for people who dye their hair...Safer Hair Dye

You no more need to worry about allergic reactions while dying your hair. Because Researchers from Gyeongsang National University have mimicked melanin to produce a dye that is less allergenic than the existing chemical used to dye hair black. Their report appears in the journal ACS Biomaterials Science & Engineering. 

Scientists have recently developed a potentially safer alternative by mimicking the hair's natural color molecule: melanin. The permanent hair dye ingredient p-phenylenediamine (PPD) has been associated, although rarely, with allergic reactions including facial swelling and rashes. Coloring hair with natural melanin would be an intuitive alternative to PPD. 

Polydopamine with iron ions transformed gray hairs into black and lasted through three wash cycles. Lighter shades could also be achieved with polydopamine by pairing it with copper and aluminum ions. Toxicity tests showed that mice treated with the colorant didn't have noticeable side effects, while those that received a PPD-based dye developed bald spots. 

http://pubs.acs.org/doi/abs/10.1021/acsbiomaterials.7b00031

Comment by Dr. Krishna Kumari Challa on March 15, 2017 at 8:12am

Synthetic yeast is about to become a reality

Scientists have constructed five more yeast chromosomes from scratch. The new work, reported online March 9 in Science, brings researchers closer to completely lab-built yeast. 

scientists might also be able to tinker with a synthetic yeast cell more efficiently than a natural one, allowing more precise engineering of everything from antiviral drugs to biofuels.

Boeke was part of a team that reported the first synthetic yeast chromosome in 2014. Now, several hundred scientists in five countries are working to make all 16 Saccharomyces cerevisiae yeast chromosomes and integrate them into living cells. With six chromosomes finished, Boeke hopes the remaining 10 will be built by the end of 2017.

Each synthetic chromosome is based on one of S. cerevisiae’s, but with tweaks for efficiency. Researchers cut out stretches of DNA that can jump around and cause mutations, as well as parts that code for the same information multiple times.  

When the researchers put chunks of synthetic DNA into yeast cells, the cells swapped out parts of their original DNA for the matching engineered snippets.

Yeast is a eukaryote — it stores its DNA in a nucleus, like human cells do. Eventually, this research could produce synthetic chromosomes for more complicated organisms.

http://science.sciencemag.org/content/355/6329/1040

http://science.sciencemag.org/content/355/6329/eaaf4597

Comment by Dr. Krishna Kumari Challa on March 15, 2017 at 7:55am

Nutrition deficiency caused by climate change

Evidence builds for lessening of certain micronutrients, protein in plants

A dinner plate piled high with food from plants might not deliver the same nutrition toward the end of this century as it does today. Climate change could shrink the mineral and protein content of wheat, rice and other staple crops, mounting evidence suggests.

Selenium, a trace element essential for human health, already falls short in diets of one in seven people worldwide. Studies link low selenium with such troubles as weak immune systems and cognitive decline. And in severely selenium-starved spots in China, children’s bones don’t grow to normal size or shape. This vital element could become sparser in soils of major agricultural regions as the climate changes, an international research group announced online February 21 in Proceedings of the National Academy of Sciences.

Likewise, zinc and iron deficiencies could grow as micronutrients dwindle in major crops worldwide, Harvard University colleagues Samuel Myers and Peter Huybers and collaborators warned in a paper published online January 6 in the Annual Review of Public Health. Futuristic field experiments on wheat and other major crops predict that more people will slip into nutritional deficits late in this century because of dips in protein content, Myers reported February 16 at the Climate and Health Meeting held in Atlanta.

G.D. Jones et al. Selenium deficiency risk predicted to increase under future climate.... Proceedings of the National Academy of Sciences. Published online February 21, 2017. doi: 10.1073/pnas.1611576114.

S.S. Myers et al. Climate change and global food systems: Potential impacts on food s.... Annual Review of Public Health. Published online January 6, 2017. doi: 10.1146/annurev-publhealth-031816-044356.

S.S. Myers et al. Increasing CO2 threatens human nutrition. Nature. Vol. 510, June 5, 2014, p. 139. doi: 10.1038/nature13179.

Comment by Dr. Krishna Kumari Challa on March 15, 2017 at 7:36am

In a remote West African village, a revolutionary genetic experiment is on its way — if residents agree to it...

Scientists in Burkina Faso are engaged in what could be the most promising, and perhaps one of the most frightening, biological experiments of our time. They are preparing for the possible release of swarms of mosquitoes that, until now, have been locked away in a research lab behind double metal doors and guarded 24/7.

The goal: to nearly eradicate the population of one species of mosquito, and with it, the heavy burden of malaria across Africa.

These scientists are planning to release mosquitoes equipped with “gene drives,” a technology that overrides nature’s genetic rules to give every baby mosquito a certain trait that normally only half would acquire. Once such an insect gets out into the wild, it will move indiscriminately and spread its modified trait without respect for political borders.

No living thing — no mammal, insect, or plant — with a gene drive has ever been set free. But if all goes as planned, it might happen here, in a remote village of about a thousand people, where the residents don’t even have a word for “gene.”

Despite such barriers, this is in some ways the most logical place to carry out the experiment. Nowhere does malaria exact a higher toll than here in sub-Saharan Africa, where hundreds of thousands die from the disease every year. And Burkina Faso already houses one of Africa’s highest-profile malaria research laboratories.

scientists still face a challenge: making sure that people understand and accept the newfangled genetic technology behind it all. That means building trust and doing basic education — explaining not only the impact of genetically engineered insects arriving in their homes, but also what genetics is in the first place.

Source: https://www.statnews.com/2017/03/14/malaria-mosquitoes-burkina-faso/

Comment by Dr. Krishna Kumari Challa on March 11, 2017 at 9:15am

Time crystals: New form of matter...

We have heard about three dimensional crystals such as salt, snow flakes etc. Now two groups of scientists have created a new kind of crystals, whose existence was first suggested by Wilczek who proposed time crystals in 2012, while wondering whether certain properties changing in time, rather than in space, could yield new phases of matter,  repeats a pattern across the fourth dimension—time.

Harvard scientists created time crystals from synthetic diamond while a University of Maryland team used charged atoms of the element ytterbium.  Two groups of scientists report that they’ve observed exotic time crystals, systems of atoms whose properties arrange themselves, or “crystallize” in time like the way solids can crystallize in space. The two groups’ vastly different atomic arrangements aren’t perpetual motion machines, weapons, or time travel devices—but their strange behavior sheds light on a whole new class of materials with properties different from any solid, liquid or gas you’ve ever encountered.

An appropriately tuned laser would flip the spins by 180 degrees. A second, identical laser burst would return the spins to their original position.

Any slight shifts to the frequency of the laser pulses would cause the ions spins to rotate by an amount different from 180 degrees. So they would not reach their starting orientation after two bursts from the spin-flip laser.

In a time crystal, the additional laser pulses introduce disorder and interactions, which make the system resilient to shifts in the frequency of the spin-flip laser. So the system cycles through a repeating pattern.

The researcher also verified that the time crystals were a closed system, and thus no energy is lost outside to the world. Also, the matter appears to have property similar to supercomputers.

http://www.nature.com/news/the-quest-to-crystallize-time-1.21595

Comment by Dr. Krishna Kumari Challa on March 7, 2017 at 8:07am

Malaria parasites make human hosts attract mosquitoes...

Malaria parasites produce a chemical that causes infected people to emit odours attractive to mosquitoes. The chemical, HMBPP, stimulates red blood vessels to produce carbon dioxide and volatile compounds. The discovery of the chemical’s role could be key to controlling malaria, a major disease.

The malaria parasite Plasmodium falciparum produces a molecule which makes infected humans emit carbon dioxide and other volatile compounds that attract mosquitoes and help them spread the disease more efficiently, a study has found. 

The molecule, HMBPP, works by stimulating red blood cells, says Ingrid Faye, researcher at the Department of Molecular Bioscience, Stockholm University (SU) and corresponding author of the study, published in Science  (February 9, 2017). 

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