Science Simplified!

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Comment by Dr. Krishna Kumari Challa on April 30, 2016 at 6:07am

Recent research by scientists at University of Florida and Union College in Lincoln, found that bed bugs strongly prefer harbourages (places of shelter) that are red and black, and they seemed to avoid colours like green and yellow. The researchers also found that the bed bugs prefer different colours depending on their sex, appetite and whether they were alone or not. These colour preferences could potentially be used in the future to help to develop more intricate and effective traps.

Chromophobia is the fear of, or aversion to, certain colours.
http://jme.oxfordjournals.org/content/early/2016/04/20/jme.tjw033

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The standard model of particle physics, the quantum-theory-based melange that bundles up our knowledge of all the forces of nature besides gravity. One of its revelations is that every fundamental matter particle has an antimatter twin – a particle identical in every way apart from having the opposite electric charge. For the familiar negatively charged electron there is a positively charged “positron”, and so on.

The big bang should have made equal amounts of matter and antimatter. But here’s the thing: when matter and antimatter meet, they annihilate in a puff of energy. So neither should have survived the early days of the universe.

Yet one of them did. Various experiments have tried to find some mismatch between processes involving matter and antimatter to explain this. The latest is LHCb at the CERN particle physics lab, which is looking for an imbalance in decays of particles known as mesons, made up of a quark and an antiquark.

Comment by Dr. Krishna Kumari Challa on April 29, 2016 at 10:16am

Reasons for dry mouth feeling
The origin of astringent mouthfeel when we eat unripe fruits, drink coffee or tea, from the perspective of lubrication by simulating the dynamic weak interaction on the tongue with model protein (mucoprotein, MP) and polyphenolic compounds (tannic acid, TA). Astringency was due to the protein-mediated lubrication failure when encountering polyphenolic molecules that normally exist, for example in unripe fruits, coffee, tea. The underlying molecular mechanism of oral tribology is widely present in nature and enables us to engineer a tongue-like polyacrylamide composite hydrogel that exhibits high TA sensitivity and to develop a scientific strategy for catching slippery fish using TA-containing gloves. These results provide novel and useful insights into the failure of biological boundary lubrication on soft tissue surface with the adsorbed proteins.
( That strange feeling in the mouth after a sip of red wine or tea, or a bite of unripe fruit. It has been described as dry, leathery or even furry. This astringent effect is caused by tannins or polyphenolic compounds that bind to mucins, lubricating proteins in the mucus membranes of the mouth. Now, in the journal Angewandte Chemie, a Chinese and Korean research team has described the relationship between astringency and this disrupted oral lubrication. Mucins consist of a central protein chain with side chains made of sugar compounds that can bind a large amount of water. Mucins form a barrier and protect sensitive mucus membranes from drying out and from chemical and mechanical interactions. They provide adequate lubrication and correspondingly low friction. This lubricating film in the oral cavity fails when tannins come in: a sip of wine causes the tongue to feel less slippery).
They found that when the tannic acid binds to the mucin, their interactions reduce the solubility of the protein in water. The mucins consequently aggregate and may precipitate, leading to a failure of the mucin lubrication film. Under a miscroscope, a substrate coated in mucin showed a flat, dense, film. After addition of tannic acid, many “defects” could be seen in the film and the surface was significantly rougher. In comparison to a glass surface coated only with water, mucin-coated glass had much lower friction when coming into contact with a soft plastic ball. Addition of tannic acid caused the friction to rise substantially. An extract of coffee beans, which also contain tannins, had a similar effect. Finally, in order to mimic a tongue, the scientists produced a mucin-containing plastic hydrogel. When wet, this elastic but barely tear-resistant material had very low friction, slipping easily through the fingers. A weight placed on an inclined surface of this hydrogel slides right off. Addition of a tannic acid solution makes the gel sticky and it begins to shrink as a result of losing water. The mechanical strength increases significantly and the elasticity decreases; the weight no longer slides off.
This finding may guide people to change their eating habits. For example, protein-rich and polyphenol-rich foods can’t be eaten together.
Astringent Mouthfeel as a Consequence of Lubrication Failure
http://onlinelibrary.wiley.com/doi/10.1002/anie.201601667/abstract;...

Comment by Dr. Krishna Kumari Challa on April 29, 2016 at 9:14am

Q: Why can't we send the satellites whose tenure is over into deep space instead of burning them up in the atmosphere?

A: Climbing out of a gravity well is tough.  It takes a lot of energy and that means it takes a lot of propellant.

It took about 40 Space Shuttle flights and several Russian Proton rockets to lift all of the hardware of ISS into low Earth orbit.  Lifting the assembled stack from LEO to beyond geosynchronous orbit would require about half as much energy again.

That much energy cannot be stored within the ISS.  It would have to be provided by a series of Russian Progress vehicles.  The problem with that is that each mile or kilometer the ISS rises makes it harder for a Progress to get to the ISS.  The Progress is only certified to fly to an altitude of 460 km (286 miles).

That means we simply don't have the technology, today, to move the ISS that high.

And if we did move it that high, it would become an out of control hunk of metal.  The ISS was designed for low Earth orbit.  Its  communication and navigation equipment  depend on being able to look up at satellites.  It would serve no value other than being preserved so that people a few hundred years from now could visit it.

The cost to develop the technology to accomplish the move and the cost of executing the move would be great.  It is not realistic to expect our legislatures to pay for such a thing.  And if they did, it would likely be in lieu of going to Mars or returning to the Moon or whatever the next great adventure will be.  Preserving the past would prevent the future.

Comment by Dr. Krishna Kumari Challa on April 29, 2016 at 6:28am

A New State of the Water Molecule found

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.
Researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of water molecules confined in hexagonal ultra-small channels - 5 angstrom across - of the mineral beryl. An angstrom is 1/10-billionth of a meter, and individual atoms are typically about 1 angstrom in diameter.

The discovery, made possible with experiments at ORNL's Spallation Neutron Source and the Rutherford Appleton Laboratory in the United Kingdom, demonstrates features of water under ultra confinement in rocks, soil and cell walls, which scientists predict will be of interest across many disciplines.

At low temperatures, this tunneling water exhibits quantum motion through the separating potential walls, which is forbidden in the classical world, according to the scientists. This means that the oxygen and hydrogen atoms of the water molecule are 'delocalized' and therefore simultaneously present in all six symmetrically equivalent positions in the channel at the same time. It's one of those phenomena that only occur in quantum mechanics and has no parallel in our everyday experience.

The existence of the tunneling state of water shown in ORNL's study should help scientists better describe the thermodynamic properties and behavior of water in highly confined environments such as water diffusion and transport in the channels of cell membranes, in carbon nanotubes and along grain boundaries and at mineral interfaces in a host of geological environments.

This discovery represents a new fundamental understanding of the behavior of water and the way water utilizes energy.

The experiments showed that, in the tunneling state, the water molecules are delocalized around a ring so the water molecule assumes an unusual double top-like shape.

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.167802

Comment by Dr. Krishna Kumari Challa on April 26, 2016 at 6:45am

Scientists have succeeded in decoding one of the secrets related to breast cells. According to science, breast cells develop two nuclei as the lactation process to nurture the newborn begins, uncovering one of the secrets to rich milk production. This change begins to occur in late pregnancy with the generation of vast numbers of cells with two nuclei, researchers have said.
Using unique three-dimensional (3-D) imaging technology, they found huge numbers of cells became binucleated (developed a second nucleus) - a process that is critical to milk production. The process - which lasts only for the duration of lactation - is important for the newborn to thrive when breast milk was the sole nutrient.
“We know that these cells are milk-producing factories. What is interesting to find is they change according to a very tightly regulated regime - they develop two nuclei, not three or four and then return to one nucleus after lactation".
Presumably this is important to avoid mishaps. The study showed how mammals, including humans, wallabies and seals, were primed to adapt to pregnancy in ways that best supported the survival of their babies, researchers said.
Based on their presence in five different species, these findings suggest that this process has evolved in mammals as a mechanism to maximise milk production, which is essential for nourishing the newborn and the survival of mammalian species. The findings were published in the journal Nature Communications.  

Comment by Dr. Krishna Kumari Challa on April 24, 2016 at 8:49am

Comment by Dr. Krishna Kumari Challa on April 23, 2016 at 7:14am

Ice-nucleating bacteria control the order and dynamics of interfacial water
Scientists recently have uncovered how tiny bacteria — nature’s ice machines — create ice crystals. Though the new study, published today in the journal Science Advances, doesn’t confirm whether these are rain-making bacteria, it points to how exactly they turn water into ice.

The bacteria, Pseudomonas syringae, have equipped themselves to cause the cold with proteins that create ice crystals at temperatures that don't normally freeze water. P. syringae live on agricultural crops, plants, and trees and use their ice-making abilities to cause frost damage. The ice crystals they produce basically shatter plants’ tissues so the bacteria can access the plants’ nutrients. We’ve even harnessed these organisms for our own purposes: P. syringae are routinely used to make artificial snow in ski resorts around the world.
In past decades, P. syringae have been found in the atmosphere, as well as in (real) snow from all over the world, from the US to Europe and even Antarctica. This study now study is the first one to show in an experiment how the ice-making mechanism actually works.
Pure water doesn’t freeze at 32 degrees Fahrenheit (0 degrees Celsius). It actually stays liquid until about - 40 degrees Fahrenheit (- 40 degrees Celsius). To freeze at higher temperatures, water needs a fleck of dust, soot, or sea salt — something to serve as a center that water molecules can latch onto. Most scientists believe that P. syringae are swept by wind from the ground to the sky. In the atmosphere, these high-flying, ice-making bacteria lower the freezing temperature to around 25 to 18 degrees Fahrenheit (- 4 to - 8 degrees Celsius) and form ice crystals. That creates clouds, which are basically agglomerations of water droplets and ice crystals.
To make rain, your clouds have to form first an ice crystal, even in the Sahara desert. As the ice crystals fall down, they turn into rain if it’s warm and snow if it’s cold. The theory that bacteria like P. syringae have a role in causing precipitation, however, has never been proved. "Intuitively it feels right, circumstantial evidence says yes, but that final link has not been done yet.
http://advances.sciencemag.org/content/2/4/e1501630

Comment by Dr. Krishna Kumari Challa on April 21, 2016 at 9:22am

Explosive cell lysis as a mechanism for the biogenesis of bacterial membrane vesicles and biofilms
A recent study by an international team of researchers has identified a phenomenon called explosive cell lysis as crucial to the production of membrane vesicles and biofilm formation, two processes that are key to how bacteria form and attack healthy cells. The study was published in Nature Communications. Membrane vesicles are tiny spheres that develop from bacterial membranes and contain a mixture of proteins, DNA, and RNA. They are important to bacteria’s ability to cause disease as they play vital roles in invasion, secretion, and signaling. They also contribute to the formation of biofilms, the slimy three-dimensional structures that form when bacteria adhere to moist surfaces such as teeth or wounds. Extracellular DNA (eDNA) is key to the structural organization of biofilms, yet it was not previously known how certain structural proteins or eDNA are released. To answer this question, the researchers used live cell microscopy of the pathogenic bacterium Pseudomonas aeruginosa to reveal that bacterial cells quickly changed from rod- to round-shaped, and then explode.
Using super-resolution microscopy to follow the explosions, they found a surprising observation. The membrane fragments produced by exploding bacteria curled up to form membrane vesicles that captured eDNA and other cellular components released by the explosion.
The team found that the explosions are caused by an enzyme (Lys) used by bacteria-infecting viruses (phages) and phage-like elements to disrupt the cell wall of their hosts. Using a mutant bacterial strain incapable of producing Lys, they discovered that the enzyme was needed to produce eDNA and membrane vesicles. Through a range of experiments, the team also demonstrated that exposure of cells to different forms of stress, such as antibiotics or DNA damaging agents, stimulated expression of the gene encoding Lys and induced explosive cell lysis. This shows that the bacterial ‘SOS’ response triggers explosive cell lysis in response to unfavorable environmental conditions, according to the researchers. This mechanism may enable bacteria to release important cellular factors for use by bacterial communities as public goods, and knowledge of its control could be used to interfere with biofilm formation of pathogenic bacteria.
http://www.nature.com/ncomms/2016/160414/ncomms11220/full/ncomms112...

Comment by Dr. Krishna Kumari Challa on April 21, 2016 at 8:44am

In a study published this week in Proceedings of the National Academy of Sciences, a pair of researchers at the INSERM–CEA Cognitive Neuroimaging Unit in France reported that the brain areas involved in math are different from those engaged in equally complex nonmathematical thinking.
The team used functional magnetic resonance imaging (fMRI) to scan the brains of 15 professional mathematicians and 15 nonmathematicians of the same academic standing. While in the scanner the subjects listened to a series of 72 high-level mathematical statements, divided evenly among algebra, analysis, geometry and topology, as well as 18 high-level nonmathematical (mostly historical) statements. They had four seconds to reflect on each proposition and determine whether it was true, false or meaningless.
The researchers found that in the mathematicians only, listening to math-related statements activated a network involving bilateral intraparietal, dorsal prefrontal, and inferior temporal regions of the brain. This circuitry is usually not associated with areas involved in language processing and semantics, which were activated in both mathematicians and nonmathematicians when they were presented with the nonmathematical statements. “On the contrary,” says study co-author and graduate student Marie Amalric, “our results show that high-level mathematical reflection recycles brain regions associated with an evolutionarily ancient knowledge of number and space.”
How Does a Mathematician's Brain Differ from That of a Mere Mortal?
Processing high-level math concepts uses the same neural networks as the basic math skills a child is born with

Comment by Dr. Krishna Kumari Challa on April 19, 2016 at 6:41am

These trained African Giant Pouched Rats can detect TB in a short span of time! It takes about nine months to fully train a TB detection rat, but once trained they can screen thousands of sputum samples every month. The idea was spurred by the superb sense of smell of these rats which had been used to detect land mines after the Mozambican civil war.

The rats pick up in their smell a group of chemicals collectively called volatile organic compounds (VOCs) and the rats alert an observer that there are TB-associated VOCs in a sample.

The same principle has been used to develop machines called electronic noses.

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