You think good cholesterol or HDL cholesterol is good for your heart and go for it. You did a wise thing ... unless you have a rare mutation in a protein called SR-BI that binds to HDL cholesterol and triggers its movement from the blood into the liver.

Those who carried the mutations tended to have high HDL cholesterol levels in the blood. But they were also, paradoxically, at higher risk for coronary heart disease!

A study published on March 10 in Science, brought his to light.

The difference between correlation and causation makes for a more complicated conversation. 

Why do we change our decisions after taking them?

There are two schools of thought on this problem. One suggestion is that changes of mind happen because we continue to weigh evidence after a choice has been made . This process is called post-decision evidence accumulation. An alternative idea is that the brain uses additional mechanisms to detect and correct previous errors. Support for this theory comes from findings that show that error-related signals are produced in the medial frontal cortex of the human brain. People who have damage to the frontal regions of the brain are also unable to “self-monitor” and identify errors they have made without external feedback. Now a pair of studies in eLife provides the most detailed account yet of the mechanisms underpinning changes of mind – and together, they indicate that both ideas could be right.

Read about the studies here: http://elifesciences.org/content/5/e14790v1?utm_source=content_aler...

An Australian artist is the only confirmed tetrachromat in the world.

What does tetrachromat mean?

The human eye is packed with millions of cone-shaped cells that allow for color to be perceived. For those with normal vision, the three types of cones allow vision of about one million distinctive colors. Some animal species including certain birds, insects, fish, and reptiles, have a fourth type of cone cell that extends color perception into the UV range. Though evolution has mostly scrubbed that fourth cone from the mammalian lineage, there is evidence that a small group of humans may have a genetic variant that allows for tetrachromacy.

So, a tetrachromat would be able to see, roughly 100 times more colours than the average human!!

Quoting Concetta, "It’s shocking to me how little color people are seeing."

The fact she is the only person (or one of a few) who sees the world totally differently makes her amazingperson. When she looks at a leaf, she sees much more than just green. “Around the edge I’ll see orange or red or purple in the shadow; you might see dark green but I’ll see violet, turquoise, blue,” she said. “It’s like a mosaic of color.”
She paints what she sees exactly. http://concettaantico.com/

where Concetta shows the world what she sees.

She conjures masterpieces in one sitting. All her paintings are insanely colorful,and feature shades you wouldn't expect to see."
The fact that we may never be able to see the world the way she does is saddening in a way.

Tetrachromacy is the condition of possessing four independent channels for conveying color information, or possessing four types of cone cells in the eye. Organisms with tetrachromacy are called tetrachromats.

In tetrachromatic organisms, the sensory color space is four-dimensional, meaning that to match the sensory effect of arbitrarily chosen spectra of light within their visible spectrum requires mixtures of at least four primary colors.

Tetrachromacy is demonstrated among several species of birds, fish, amphibians, reptiles and insects. It was also the normal condition of most mammals in the past; a genetic change made the majority of species of this class eventually lose two of their four cones.

Using flashes of blue light, scientists have pulled forgotten memories out of the foggy brains of mice engineered to have signs of early Alzheimer’s disease. This memory rehab feat, described online March 16 in Nature, offers new clues about how the brain handles memories, and how that process can go awry.
To recover a lost memory, scientists first had to mark it. Neuroscientist Susumu Tonegawa of MIT and colleagues devised a system that tagged the specific nerve cells that stored a memory — in this case, an association between a particular cage and a shock. A virus delivered a gene for a protein that allowed researchers to control this collection of memory-holding nerve cells. The genetic tweak caused these cells to fire off signals in response to blue laser light, letting Tonegawa and colleagues call up the memory with light delivered by an optic fiber implanted in the brain.

A day after receiving a shock in a particular cage, mice carrying two genes associated with Alzheimer’s seemed to have forgotten their ordeal; when put back in that cage, these mice didn’t seem as frightened as mice without the Alzheimer’s-related genes. But when the researchers used light to restore this frightening memory, it caused the mice to freeze in place in a different cage. (Freezing in a new venue showed that laser activation of the memory cells, and not environmental cues, caused the fear reaction.)

The fact that this memory could be pulled out with light helps clarify the source of memory trouble for people with Alzheimer’s. People in the early stages of the disease seem able to create new memories, but then rapidly forget them, he says. Memories can sometimes be strengthened with reminders and clues from the environment, suggesting that they are “somewhere in there,” but not retrievable.
Further experiments with the mice showed that the fear memory could be strengthened by forcing it to appear multiple times. This memory boot camp worked because it boosted the number of docking sites on memory-holding nerve cells in the mice with Alzheimer’s-related genes. Usually, these docking sites — knobs called dendritic spines that receive messages from other nerve cells — become scarcer with age. To counter that, Tonegawa and colleagues used light to repeatedly activate nerve cells that in turn activate the memory-holding cells. Compared with mice that didn’t get this strengthening treatment, mice with the Alzheimer’s genes that underwent this process were more fearful of the cage where they had received a shock, even six days later.
The results are only experimental but several insights have been gained on how memory works.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature17172...

A parallel realm of carbon-polluting activity - ranging from email exchanges to social network chatter (tweets, posts etc) to streaming movies on smartphones - has slipped largely unnoticed under the climate change radar. In isolation, these discrete units of our virtual existence seem weightless and without cost.
A short email, for example, is estimated to add about four grams of CO2-equivalent (CO2e) into the atmosphere.
By comparison, humanity emits some 40 billion tonnes of CO2 every year.
But as the digital era deepens, the accumulated volume of virtual messages has become a significant part of humanity's carbon footprint.
"Electricity consumption related to the growth of digital technologies is exploding," notes Alain Anglade of the French Environment and Energy Management Agency. In France it already accounts for more than 10% of total electricity use, he said, a percentage that holds for many developed countries. To see the big picture, it helps to break it down.
Sending five dozen of those four-gram emails in a day from your smartphone or laptop, for example, is the equivalent of driving an average-size car a kilometre. AFP

Role of bacteria in platinum formation...
Australian scientists have uncovered the important role of specialist bacteria in the formation and movement of platinum and related metals in surface environments. Published in the journal Nature Geoscience, the research has important implications for the future exploration of platinum group metals.
These platinum group elements are strategically important metals, but finding new deposits is becoming increasingly difficult due to our limited understanding of the processes that affect the way they are cycled through surface environments.
This research reveals the key role of bacteria in these processes. This improved bio geochemical understanding is not only important from a scientific perspective but scientists hope will also lead to new and better ways of exploring for these metal.
Traditionally it was thought that these platinum group metals only formed under high pressure and temperature systems deep underground, and that when they were brought to the surface through weathering and uplift, they just sat there and nothing further happened to them.

Now scientists have shown that that is far from the case. They have linked specialised bacterial communities, found in biofilms on the grains of platinum group minerals at three separate locations around the world, with the dispersion and re-concentration of these elements in surface environments.

They've shown that nuggets of platinum and related metals can be reformed at the surface through bacterial processes.
Source: University of Adelaide

If you have a very small circle of friends and you are happy about it, then it might be a sign that you are intelligent as a new study has revealed that loners tend to be more intellectual than others.
The research is published in the British Journal of Psychology.

Scientists find ancient viral strands hiding in human DNA
"This is a thrilling discovery"
Researchers have discovered 19 unique fragments and stands of viral DNA in the genomes of modern humans.

Scientists analyzed the genomes of some 2,500 people from around the world. The viral fragments were identified by comparing the genomes to a "reference" human genome, an average of sorts. The comparative analysis allowed researchers to hone in on unique segments and locate foreign code.

Human endogenous retroviruses, or HERVs, are ancient viruses that succeeded in depositing DNA-based copies of their RNA genetic material into the genomes of early humans.
"Discovery of unfixed endogenous retrovirus insertions in diverse human populations"
http://www.pnas.org/content/early/2016/03/16/1602336113
The scientists say...this is because...

The human endogenous retrovirus (HERV) group HERV-K contains nearly intact and insertionally polymorphic integrations among humans, many of which code for viral proteins. Expression of such HERV-K proviruses occurs in tissues associated with cancers and autoimmune diseases, and in HIV-infected individuals, suggesting possible pathogenic effects. Proper characterization of these elements necessitates the discrimination of individual HERV-K loci; such studies are hampered by our incomplete catalog of HERV-K insertions, motivating the identification of additional HERV-K copies in humans. By examining >2,500 sequenced genomes, they have discovered 19 previously unidentified HERV-K insertions, including an intact provirus without apparent substitutions that would alter viral function, only the second such provirus described. Their results provide a basis for future studies of HERV evolution and implication for disease.

AI to Devise Unthinkable Experiments
Quantum mechanics predicts a number of, at first sight, counterintuitive phenomena. It therefore remains a question whether our intuition is the best way to find new experiments. Here, we report the development of the computer algorithm Melvin which is able to find new experimental implementations for the creation and manipulation of complex quantum states. Indeed, the discovered experiments extensively use unfamiliar and asymmetric techniques which are challenging to understand intuitively. The results range from the first implementation of a high-dimensional Greenberger-Horne-Zeilinger state, to a vast variety of experiments for asymmetrically entangled quantum states—a feature that can only exist when both the number of involved parties and dimensions is larger than 2. Additionally, new types of high-dimensional transformations are found that perform cyclic operations. Melvin autonomously learns from solutions for simpler systems, which significantly speeds up the discovery rate of more complex experiments. The ability to automate the design of a quantum experiment can be applied to many quantum systems and allows the physical realization of quantum states previously thought of only on paper.
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.090405

A Korean research team has engineered gut bacteria to create non-natural polymers in a biorefinery—allowing various plastics to be made in an environmentally-friendly and sustainable manner. The research was published in Nature Biotechnology.
biorefineries which transform non-edible biomass into fuel, heat, power, chemicals and materials have received a great deal of attention as a sustainable alternative to decreasing the reliance on fossil fuels. Renewable non-food biomass could potentially replace petrochemical raw materials to produce energy sources, useful chemicals, or a vast array of petroleum-based end products such as plastics, lubricants, paints, fertilizers and vitamin capsules. In the present study, a team headed by Distinguished Professor Lee Sang Yup of the Korea Advanced Institute of Science and Technology (KAIST) adopted a systems metabolic engineering approach to develop a microorganism that can produce various non-natural polymers which have biomedical applications. According to the researchers, this approach is the first successful example of biological production of poly(lactate-co-glycolate) (PLGA) and several novel copolymers from renewable biomass by one-step direct fermentation of metabolically engineered Escherichia coli (E. coli) bacteria. The researchers drew inspiration from the biosynthesis process for polyhydroxyalkanoates, biologically-derived polyesters produced in nature by the bacterial fermentation of sugar or lipid. From there, they designed a metabolic pathway for the biosynthesis of PLGA through microbial fermentation directly from carbohydrates in E. coli strains. PLGA is a biodegradable, biocompatible and non-toxic polymer. PLGA has been widely used in biomedical and therapeutic applications such as surgical sutures, prosthetic devices, drug delivery, and tissue engineering. In order to produce PLGA by microbial fermentation directly from carbohydrates, the team incorporated external and engineered enzymes as catalysts to co-polymerize PLGA while establishing a few additional metabolic pathways for the biosynthesis to produce a range of different non-natural polymers. This bio-based synthetic process for PLGA and other polymers could substitute for existing complicated chemical production methods. Lee and his team has also managed to produce a variety of PLGA copolymers with different monomer compositions such as the US Food and Drug Administration-approved monomers 3-hydroxyburate, 4-hydroxyburate, and 6-hydroxyhexanoate. Newly applied bioplastics such as 5-hydroxyvalerate and 2-hydroxyisovalerate were also made.http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt.3485.html

South Asians share ancestry with a mysterious population...
Many bloodlines around the world, particularly of South Asian descent, may actually be a bit more Denisovan- a mysterious population of hominids.
Denisovans lived around the same time as the Neanderthals - scientists have revealed. The team from Harvard Medical School and University of California-Los Angeles (UCLA) has created a world map and also used comparative genomics to make predictions about where Denisovan and Neanderthal genes may be impacting modern human biology. The analysis also proposes that modern humans interbred with Denisovans about 100 generations after their trysts with the Neanderthals.
Denisovan genes can potentially be linked to a more subtle sense of smell in Papua New Guineans and high-altitude adoptions in Tibetans.
Meanwhile, Neanderthal genes found in people around the world most likely contribute to tougher skin and hair. Most non-Africans possess at least a little bit Neanderthal DNA.
There was also negative selection to systematically remove ancestry that may have been problematic from modern humans. We can document this removal over the 40,000 years since these admixtures occurred.
They found evidence that both Denisovan and Neanderthal ancestry has been lost from the X chromosome as well as genes expressed in the male testes.
The team theorises that this has contributed to reduced fertility in males, which is commonly observed in other hybrids between two highly divergent groups of the same species.
The researchers collected their data by comparing known Neanderthal and Denisovan gene sequences across more than 250 genomes from 120 non-African populations publicly available through the Simons Genome Diversity Project.
The new map of archaic ancestry was published in the journal Current Biology.

Scientists have built a bacterium that contains the minimal genetic ingredients needed for free living.

This bacterium’s entire set of genetic blueprints, its genome, consists of only 473 genes, including 149 whose precise biological function is unknown, researchers report in the March 25 Science.

The newly-created bacterium contains a minimalist version of the genome of Mycoplasma mycoides. Mycoplasma already have some of the smallest known genomes. M. mycoides used in the experiments started with 901 genes. In comparison, other bacteria, including E. coli, may have 4,000 to 5,000 genes. Humans have more than 22,000 genes, although not all are necessary.

In 2010, researchers at the J. Craig Venter Institute in La Jolla, Calif., replicated the entire genome of M. mycoides and popped it into a cell of a different species, Mycoplasma capricolum, creating what some people called the first synthetic organism. The new work strips the M. mycoides genome down to its essential elements before transplanting it to the M. capricolum shell, producing a minimal bacteria dubbed syn3.0.

Researchers hope syn3.0’s uncluttered genome will teach them more about the basics of biology. Such minimal genome bacteria also may be chassis on which to build custom-made microbes for producing drugs or chemicals.

Somebody asked this Q...Would scientists go off into panic if something unusual happens like stars alongside everything else except the Sun mysteriously vanished without reason?
A: On the contrary, scientists would be the last ones to panic, because they would have something to do. Which would be to grab every appropriate instrument they could find, and science the hell out of the problem while everybody else fan around panicking.
in general scientists would not see this as a panic event. There's a tendency for scientists to ignore personal risk when faced with mystery, and this would be a large mystery. The phenomenun is similar to that of photographers faced with disasters or riots; they act as though the camera makes them immune to whatever is on the other side of the lens.
Scientists would probably be one of the few NOT going into a panic.

Most people would be like "What the hell is going on? It's the apocalypse repent your sins satan is upon us ahhrghhhg!"

A scientists would be like "Whoa, that's interesting. Let's try to figure out what just happened!"
Not all of them. A good number will be busy trying to take measurements of the darkness surrounding us and figure out what is causing it. I myself can already think of several hypotheses for explaining the phenomenon you described.

Then they would use their data to figure out if this darkness is dangerous to us, and what we can do to protect ourselves from it, or how we can use it to our benefit. Meanwhile they will continue to study it and collect more data. Eventually they will be able to make pretty good predictions about what the darkness will do in the next few years, or whether it will stay around or go away.

Good scientists don't have the time to freak out and panic. There's always something better to do or think about.

On the other hand, what would superstitious people do?

It's a rhetorical question, I don't really need to know.
No, it could have a very simple reason.

It could be something like a nebula we are passing through that blotted the Stars out and was charged and the charge damaged the spacecraft and satellites.

Until we found out what exactly happened most scientists would be busy trying to understand it and would not make any announcements.

Most scientists, however not creationists or ID supporters who would probably reinterpret one of the biblical prophecies of signs for Armageddon. It states the stars will fall to Earth. Obviously that is impossible but the ignorant power crazed priests were not aware that stars are Suns (they thought they were decorations or lights in the 'Dome of the sky' that is supposed to separate water on Earth and water above the Earth letting God make rain (they didn't know about evaporation and condensation), it's why they are called stars and not Suns by the general population.

Other possibilities:
A super dense concentration of dark matter.
If the sun was also gone, a possible effect on the upper atmosphere that made it opaque (not see through).
I don't think there would be "panic" exactly - but you can bet that a lot of scientists would be dropping everything to investigate it. Scientists love nothing more than to find things that don't fit with current theory because it's an opportunity to learn more and fix whatever problem that theory has. So generally, "excitement" would probably be the first emotion.

How scientists can reduce their carbon footprint
Cutting down on long-distance air travel is the best way to reduce the emission of greenhouse gases by the scientific community.
http://elifesciences.org/content/5/e15928v1?utm_source=content_aler...

New state of matter detected in a two-dimensional material

A team of quantum physicists has discovered a mysterious new state of matter in a two-dimensional material. Scientists are calling the state "quantum spin liquid."

The novel state was predicted 40 years ago. Now, researchers have direct evidence.

Quantum spin liquid is characterized by the breaking apart of electrons. The electron fragments are called Majorana fermions. While observing particle behavior inside a graphene-like 2D material, scientists at the University of Cambridge recorded the signatures of these fractional particles.

What they saw matched the predictions of theoretical models for a quantum spin liquid.

The mysterious state explains anomalies inside magnetic materials. Electrons in magnetic materials each behave like miniature bar magnets. As a material is cooled, the electrons each line up in accordance with magnetic north -- all pointing the same direction.

This doesn't happen in magnetic materials boasting quantum spin liquid, where electrons refuse to align. Instead, their quantum fluctuations result in a soup of entangled electrons.
This is a new addition to a short list of known quantum states of matter.
http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4604.html

Stop wasting food to manage climate change to good levels - scientists

Reducing food waste around the world would help curb emissions of planet-warming gases, lessening some of the impacts of climate change such as more extreme weather and rising seas, scientists said on 7th April, 2016.
Up to 14 percent of emissions from agriculture in 2050 could be avoided by managing food use and distribution better, according to a new study from the Potsdam Institute for Climate Impact Research (PIK).
"Agriculture is a major driver of climate change, accounting for more than 20 percent of overall global greenhouse gas emissions in 2010".
"Avoiding food loss and waste would therefore avoid unnecessary greenhouse gas emissions and help mitigate climate change."
Between 30 and 40 percent of food produced around the world is never eaten, because it is spoiled after harvest and during transportation, or thrown away by shops and consumers.
The share of food wasted is expected to increase drastically if emerging economies like China and India adopt Western food habits, including a shift to eating more meat, the researchers warned.
Richer countries tend to consume more food than is healthy or simply waste it, they noted.

Food loss and waste hurts people, costs money and harms the planet. Cutting (it) is a no-brainer, according to these scientists.

Melanesians are the only people known to have DNA from two ancient human ‘cousins’ - i.e., they got a double dose of Stone Age DNA!
Unlike people in the rest of world, some modern-day Pacific Islanders have inherited genes from two different groups of Stone Age relatives. That’s the conclusion of new research. And the ancient DNA they carry still affects their health and well-being — in a good way.

Melanesians live in a group of islands northeast of Papua New Guinea. Their ancestors mated with Neandertals, the new data show. They also mated with mysterious Neandertal relatives, known as Denisovans.

Population geneticist Benjamin Vernot and his colleagues made the discovery. At the time, Vernot was working at the University of Washington in Seattle. His group published its findings online March 17 in Science.

The new study looked at DNA that both parents pass to their children. (Other DNA is typically passed down only by moms.) As earlier studies had shown, non-African people have a little bit of Neandertal DNA.

This includes the Melanesians. On average, they inherited 1.5 to 4 percent of their DNA from Neandertals. But Melanesians have DNA from Denisovans too. This makes up 1.9 to 3.4 percent of their DNA, the new study finds. (Today’s Africans have little to no Neandertal or Denisovan DNA.)

In modern Melanesians, the bits of Neandertal and Denisovan DNA include genes involved in metabolism and immunity. That means mating with other hominids — other species of human ancestors — may have helped ancient humans thrive, the scientists say.

Scientists blast comet-like ice with radiation like that in space, creating RNA - a key building block for life!
Scientists have produced the first formation of a key sugar required for life as we know it. By creating ices similar to those detected by the European Space Agency's Rosetta mission, which made the first landing on a comet, scientists were able to produce ribose, a sugar that serves as an important ingredient in RNA, an essential ingredient for life.
Cornelia Meinert, an associate scientist at the University Nice Sophia Antipolis led experiments that dosed icy materials produced in a laboratory with radiation similar to what comets would have received in the early life of the solar system, resulting in the creation of ribose.
Meinert and her colleagues recreated ices detected by Rosetta's Philae lander when it touched down on Comet 67P in 2014. In a lab, they created interstellar ices under what Meinert called "realistic astrophysical conditions" — in other words, within a vacuum, surrounded by low temperatures. Then, they blasted the samples with radiation simulating energy from the young sun, which was far more active than today's star, along with cosmic rays from the rest of the galaxy. Some of the material from the ices evaporated, while the leftover material created an organic residue. Sampling this residue revealed not only sugars but also amino acids, alcohols and other material.

The research was published online today (April 7) in the journal Science. - 
Source: http://www.space.com

Plan to Send Probes to the Nearest Star
Funded by Russian entrepreneur Yuri Milner and with the blessing of Stephen Hawking, Breakthrough Starshot aims to send probes to Alpha Centauri in a generation
For Yuri Milner, the Russian Internet entrepreneur and billionaire philanthropist who funds the world’s richest science prizes and searches for extraterrestrial intelligence, the sky is not the limit—and neither is the solar system. Flanked by physicist Stephen Hawking and other high-profile supporters today in New York, Milner announced his most ambitious investment yet: $100 million toward a research program to send robotic probes to nearby stars within a generation.
- Scientific American

The sugar, cyclodextrin, removed cholesterol that had built up in the arteries of mice fed a high-fat diet, researchers report April 6 in Science Translational Medicine. The sugar enhances a natural cholesterol-removal process and persuades immune cells to soothe inflammation instead of provoking it, say immunologist Eicke Latz and colleagues.

Cyclodextrin, more formally known as 2-hydroxypropyl-beta-cyclodextrin, is the active ingredient in the air freshener Febreze. It is also used in a wide variety of drugs; it helps make hormones, antifungal chemicals, steroids and other compounds soluble. If the new results hold up in human studies, the sugar may also one day be used to liquefy cholesterol that clogs arteries.

Other researchers say the approach is promising, but must be tested in clinical trials. The sweet molecule is generally considered safe, but injecting it may raise the risk of liver damage or hearing loss.
http://stm.sciencemag.org/content/8/333/333ra50

A new particle?!

Why can anyone easily shot down a helicopter?
The reason they are so prone to being shot down according to experts is two fold... they rely on the tail rotor (or boom in the case of a NOTAR design) to produce the anti-torque to counter act the torque that needs to be applied to the main rotor. Take out that tail rotor and you can no longer power or even generate lift at all from the main rotor without spinning out of control (due to induced drag of the rotor blades). This is of course not applicable to co-axial helicopters which use two main rotor blades counter spinning to counteract torque. A shrouded tail rotor is less likely to strike objects and suffer catastrophic failure but is still susceptible to bullets and other projectiles hitting it. A NOTAR design using the Coanda effect has an extremely resilient anti torque mechanism but gives up maneuverability.

Secondly, the main rotor hub is an extremely complex piece of machinery. It must control collective pitch, cyclical pitch, spin extremely fast ( typically around 5 - 10 revs per second) which causing huge forces pulling it apart and essentially hold the weight plus maneuvering load of the helicopter. A great number of things can go wrong.

Losing power to the main rotor means certain death, but it is actually fairly easy to recover from and helicopter pilots actually practice it pretty regularly. They perform what's called an autorotation in which they immediately (upon sensing engine failure) lower the collective pitch to maintain rotor momentum, which will cause the helicopter to start to descent. They then push the nose forward to gain a forward momentum and start picking out a place to land (or crash depending on the rest of how the scenario plays out). The forward momentum allows the rotor to continue generating lift and the rotational momentum of the rotor will be used as a last second flare to slow descent and hopefully land smoothly. The most dangerous thing for a helicopter to do is to hover (no horizontal movement) at a low height above ground because there will be little that can be done to recover from a loss of power to the main rotor.

Also - 

1. They can't fly that fast, or at least not as fast as airplanes. This makes it easier to engage them with all kinds of AA weapons, even including small weapon fire.
2. They have to fly low, especially when they are supposed to give ground support, unload troop, or extract them from the battlefield. Once again, this makes them vulnerable to all kinds of weapons.
3. They have to be stationary during critical moments, such as unloading and loading personnel, or once again proving air support (sometimes). Not only are they easier to shoot at, but they also have less "energy" to perform evasive maneuvers, or get out of there.

To summarise it all together, helicopters have less "energy" when they are being shot at, in the sense that they are lower in altitude, and usually slower, if not standing perfectly still. This makes them vulnerable to small weapons fire, and basically does not allow the pilot to perform any kind of evasive maneuver.

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.

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

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...

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

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.  

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

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.

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;...

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.

Biomechanics of the Peacock’s Display: How Feather Structure and Resonance Influence Multimodal Signaling
Courtship displays may serve as signals of the quality of motor performance, but little is known about the underlying biomechanics that determines both their signal content and costs. Peacocks (Pavo cristatus) perform a complex, multimodal “train-rattling” display in which they court females by vibrating the iridescent feathers in their elaborate train ornament. Here we study how feather biomechanics influences the performance of this display using a combination of field recordings and laboratory experiments. Using high-speed video, we find that train-rattling peacocks stridulate their tail feathers against the train at 25.6 Hz, on average, generating a broadband, pulsating mechanical sound at that frequency. Laboratory measurements demonstrate that arrays of peacock tail and train feathers have a broad resonant peak in their vibrational spectra at the range of frequencies used for train-rattling during the display, and the motion of feathers is just as expected for feathers shaking near resonance. This indicates that peacocks are able to drive feather vibrations energetically efficiently over a relatively broad range of frequencies, enabling them to modulate the feather vibration frequency of their displays. Using our field data, we show that peacocks with longer trains use slightly higher vibration frequencies on average, even though longer train feathers are heavier and have lower resonant frequencies. Based on these results, we propose hypotheses for future studies of the function and energetics of this display that ask why its dynamic elements might attract and maintain female attention. Finally, we demonstrate how the mechanical structure of the train feathers affects the peacock’s visual display by allowing the colorful iridescent eyespots–which strongly influence female mate choice–to remain nearly stationary against a dynamic iridescent background.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.01...

Plastics in Food - Bisphenol A and food safety: Lessons from developed to developing countries

BPA is used to make certain plastics or resins. It can seep into food or drinks from food containers or the protective linings of cans -  
Modern lifestyles and changes in the socio-economic characteristics of households have stimulated current developments in food technology, processing and packaging. Chemicals such as bisphenol A (BPA) are known to migrate from food packaging into the food, resulting in human exposure to these chemicals. Similarly, BPA can migrate from baby feeding bottles into milk. BPA has been associated with adverse effects attributed to its estrogenic properties in various animal models. This review analyzed peer-reviewed publications in the English literature on human BPA exposure and regulations in developing countries compared to developed countries. BPA has been reduced or eliminated from food packaging and contact materials such as baby bottles in developed countries either voluntarily or by legislation. The meager data from developing countries shows that human BPA exposure in developing countries is similar to that in developed countries. With minor exceptions, BPA restriction, voluntary or legal, is virtually absent in developing countries of Africa, SE Asia, and South and Central America.

http://www.sciencedirect.com/science/article/pii/S0278691516300898

Why are Itches contagious? 

Itching can be "caught" just by watching someone else having a good scratch, scientists have confirmed.

Itching becomes contagious because the brain becomes hypersensitive when someone nearby scratches and so misinterprets any kind of physical sensation on our skin as an itch.

The researchers found empathy (a willingness to take another's viewpoint) did not correlate with the phenomenon. Participants who scored high on neuroticism were significantly more likely than others to experience itch contagion, the researchers found. 

There is an evolutionary basis for this mundane behavior.
The world of our Paleolithic ancestors was a pruritogenic wilderness, full of plants and bugs that posed more of a threat than mere skin irritation. So a scratch is a preemptive strike against the more noxious aftereffects if that relatively innocuous warning signal is ignored.

Growing sensitive to itching when one member of the group is scratching could help to identify parasite infestations early and help to stop them spreading.

Medical error—the third leading cause of death! That too in developed countries!
Medical errors the third leading cause of death, only after heart disease and cancer.

Lab test failures contribute to delayed or wrong diagnoses and unnecessary costs and care. Most people will experience at least one diagnostic error in their life. Errors related to lab tests are more common than you might think.

Misperceptions that diagnostic laboratory tests are always correct and useful exist even though experts say ‘no test performs perfectly’.

Whether due to misuse or a failure mode, all lab tests have limitations. Some of the most common reasons include mistakes in ordering lab tests—meaning the right tests are not ordered at the right time—and problems with the accuracy, availability, and interpretation of their results.

From a patient’s perspective the best thing you can do to overcome lab test-related errors is be informed about the possible problems that could arise and what to ask to try to avoid them.

http://www.bmj.com/content/bmj/353/bmj.i2139.full.pdf

                                         0099--0099

The cost of poor blood specimen quality and errors in preanalytical processes

Preanalytical phase errors may account for 75% of total laboratory errors.

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One failure can affect patient treatment and multiply into significant costs.

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A model can estimate the cost of poor specimen quality on total operating costs.

http://www.sciencedirect.com/science/article/pii/S0009912013002786

Climate change may contribute to rising rates of chronic kidney disease
Chronic kidney disease that is not associated with traditional risk factors appears to be increasing in rural hot communities as worldwide temperature progressively rises. The condition has likely increased due to global warming and an increase in extreme heat waves, and it is having a disproportionate impact on vulnerable populations, say investigators.
Climate change may be accelerating rates of chronic kidney disease caused by dehydration and heat stress, according to research appearing in an upcoming issue of the Clinical Journal of the American Society of Nephrology (CJASN). The findings suggest that a condition called heat stress nephropathy may represent a disease of neglected populations, but one that may emerge as a major cause of poor kidney health in the near future.
Over the next century, climate change and resulting water shortages are likely to affect a wide variety of health issues related to dehydration and heat stress -- with risks increasing for cognitive dysfunction, malnutrition, water-borne infectious diseases, chronic kidney disease, and other conditions.
Reports of heat stress nephropathy -- or chronic kidney disease consistent with heat stress -- that are already occurring throughout the world.

The investigators found that chronic kidney disease that is not associated with traditional risk factors appears to be increasing in rural hot communities as worldwide temperature progressively rises. They believe the risk for heat stress nephropathy has increased due to global warming and an increase in extreme heat waves, and it is having a disproportionate impact on vulnerable populations, such as agricultural workers. Decreasing precipitation exacerbates this epidemic by reducing the water supply and water quality as temperatures climbs.

The researchers recommend that governments and scientists work together to conduct epidemiological and clinical studies to document the presence of these epidemics and their magnitude. Interventions are also needed to improve worksite conditions and ensure adequate hydration.

Climate change has led to significant rise of 0.8°C–0.9°C in global mean temperature over the last century and has been linked with significant increases in the frequency and severity of heat waves (extreme heat events). Climate change has also been increasingly connected to detrimental human health. One of the consequences of climate-related extreme heat exposure is dehydration and volume loss, leading to acute mortality from exacerbations of pre-existing chronic disease, as well as from outright heat exhaustion and heat stroke. Recent studies have also shown that recurrent heat exposure with physical exertion and inadequate hydration can lead to CKD that is distinct from that caused by diabetes, hypertension, or GN. Epidemics of CKD consistent with heat stress nephropathy are now occurring across the world. Here, we describe this disease, discuss the locations where it appears to be manifesting, link it with increasing temperatures, and discuss ongoing attempts to prevent the disease. Heat stress nephropathy may represent one of the first epidemics due to global warming. Government, industry, and health policy makers in the impacted regions should place greater emphasis on occupational and community interventions.
http://cjasn.asnjournals.org/content/early/2016/05/04/CJN.13841215

Dust storms: Dust is a powerful, but invisible, force. It shapes Earth’s environment in ways that few people realize. Every year, three to four billion tons of dust is lifted into the air around the world by wind. That’s enough to cover a city of moderate area to a depth of 5 meters (16 feet).
Once airborne, this dust can travel thousands of kilometers. It nourishes some of our planet’s largest and lushest forests — allowing them to grow where otherwise they could not. It triggers rain and snowfall. It may even ferry diseases across oceans.

British and American Scientists have been trying to figure this out for half a century, ever since someone accidentally discovered how far dust can travel. Researchers are finding tiny amounts of several elements — sodium, potassium and calcium — in the air just above the ocean. They thought it came from tiny bits of salt lofted up from seawater as bubbles burst on the ocean’s surface.

But soon discovered the elements didn’t come from salt.The mud was from the bottom of the ocean, often from a depth of more than 3,000 meters (about 10,000 feet). Some samples had come from parts of the ocean that were thousands of kilometers from land. They were all cluttered with tiny flecks of crystals — minerals known as quartz and mica. These minerals were known to form on land, not in the sea. The minerals on the sea floor and the sodium, potassium and calcium in the air above the water were coming from the same source: tiny grains of dust. That dust might ride the winds for thousands of kilometers before finally settling down onto the ocean. If true, it would mean that 30 to 80 percent of the mud on the sea floor actually came from distant lands!

And they found that this dust is coming from deserts like Sahara! Around 30 billion kilograms (33 million tons) of Saharan dust flew over the Atlantic Ocean toward Barbados each year. For much of the year, dust from the Sahara drifts toward the Caribbean and southeastern United States. But winds shift during the winter. Then they began carrying Bodélé dust a different way over the Atlantic Ocean. When it reaches South America, on the other side, it does something truly amazing.

Attention deficit hyperactivity disorder (ADHD), usually diagnosed in children, may show up for the first time in adulthood, two recent studies suggest.
And not only can ADHD appear for the first time after childhood, but the symptoms for adult-onset ADHD may be different from symptoms experienced by kids, the researchers found.
Although the nature of symptoms differs somewhat between children and adults, all age groups show impairments in multiple domains – school, family and friendships for kids and school, occupation, marriage and driving for adults.
However, some newly diagnosed adults might have had undetected ADHD as children. Support from parents and teachers or high intelligence, for example, might prevent ADHD symptoms from emerging earlier in life.

And these people should take immediate medical assistance to alleviate their problems.

According to new calculations, Earth’s center is more than two years younger than its surface!
How is this possible?
In Einstein’s general theory of relativity, massive objects warp the fabric of spacetime, creating a gravitational pull and slowing time nearby. So a clock placed at Earth’s center will tick ever-so-slightly slower than a clock at its surface. Such time shifts are determined by the gravitational potential, a measure of the amount of work it would take to move an object from one place to another. Since climbing up from Earth’s center would be a struggle against gravity, clocks down deep would run slow relative to surface timepieces.

Over the 4.5 billion years of Earth’s history, the gradual shaving off of fractions of a second adds up to a core that’s 2.5 years younger than the planet’s crust, researchers estimate in the May European Journal of Physics.

The new calculation neglects geological processes, which have a larger impact on the planet’s age. For example, Earth’s core probably formed earlier than its crust. Instead, says study author Ulrik Uggerhøj of Aarhus University in Denmark, the calculation serves as an illustration of gravity’s influence on time — very close to home.

U. I. Uggerhoj, R. E. Mikkelsen, and J. Faye. The young centre of the Earth. European Journal of Physics. Vol. 37 May 2016, p. 035602. doi: 10.1088/0143-0807/37/3/035602.

The young centre of the Earth

http://iopscience.iop.org/article/10.1088/0143-0807/37/3/035602

A Fifth Force of Nature?
A laboratory experiment in Hungary has spotted an anomaly in radioactive decay that could be the signature of a previously unknown fifth fundamental force of nature, physicists say—if the finding holds up.
Attila Krasznahorkay at the Hungarian Academy of Sciences’s Institute for Nuclear Research in Debrecen, Hungary, and his colleagues reported their surprising result in 2015 on the arXiv preprint server, and this January in the journal Physical Review Letters. But the report – which posited the existence of a new, light boson only 34 times heavier than the electron—was largely overlooked.
Again on April 25, a group of US theoretical physicists brought the finding to wider attention by publishing its own analysis of the result on arXiv. The theorists showed that the data didn’t conflict with any previous experiments—and concluded that it could be evidence for a fifth fundamental force. Researchers there were sceptical but excited about the idea.
Gravity, electromagnetism and the strong and weak nuclear forces are the four fundamental forces known to physics—but researchers have made many as-yet unsubstantiated claims of a fifth. Over the past decade, the search for new forces has ramped up because of the inability of the standard model of particle physics to explain dark matter—an invisible substance thought to make up more than 80% of the Universe’s mass. Theorists have proposed various exotic-matter particles and force-carriers, including “dark photons”, by analogy to conventional photons that carry the electromagnetic force.
Krasznahorkay says his group was searching for evidence of just such a dark photon – but Feng’s team think they found something different. The Hungarian team fired protons at thin targets of lithium-7, which created unstable beryllium-8 nuclei that then decayed and spat out pairs of electrons and positrons. According to the standard model, physicists should see that the number of observed pairs drops as the angle separating the trajectory of the electron and positron increases. But the team reported that at about 140º, the number of such emissions jumps—creating a ‘bump’ when the number of pairs are plotted against the angle—before dropping off again at higher angles.

Krasznahorkay says that the bump is strong evidence that a minute fraction of the unstable beryllium-8 nuclei shed their excess energy in the form of a new particle, which then decays into an electron–positron pair. He and his colleagues calculate the particle’s mass to be about 17 megaelectronvolts (MeV).

 https://arxiv.org/abs/1504.01527

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.042501