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# Wikipedia-size maths proof too big for humans to check

If no human can check a proof of a theorem, does it really count as mathematics? That's the intriguing question raised by the latest computer-assisted proof. It is as large as the entire content of Wikipedia, making it unlikely that will ever be checked by a human being.

"It might be that somehow we have hit statements which are essentially non-human mathematics," says Alexei Lisitsa of the University of Liverpool, UK, who came up with the proof together with colleague Boris Konev.

The proof is a significant step towards solving a long-standing puzzle known as the Erdős discrepancy problem. It was proposed in the 1930s by the Hungarian mathematician Paul Erdős, who offered \$500 for its solution.

Imagine a random, infinite sequence of numbers containing nothing but +1s and -1s. Erdos was fascinated by the extent to which such sequences contain internal patterns. One way to measure that is to cut the infinite sequence off at a certain point, and then create finite sub-sequences within that part of the sequence, such as considering only every third number or every fourth. Adding up the numbers in a sub-sequence gives a figure called the discrepancy, which acts as a measure of the structure of the sub-sequence and in turn the infinite sequence, as compared with a uniform ideal.

Erdős thought that for any infinite sequence, it would always be possible to find a finite sub-sequence summing to a number larger than any you choose - but couldn't prove it. It is relatively easy to show by hand that any way you arrange 12 pluses and minuses always has a sub-sequence whose sum exceeds 1. That means that anything longer – including any infinite sequence – must also have a discrepancy of 1 or more. But extending this method to showing that higher discrepancies must always exist is tough as the number of possible sub-sequences to test quickly balloons.

Now Konev and Lisitsa have used a computer to move things on. They have shown that an infinite sequence will always have a discrepancy larger than 2. In this case the cut-off was a sequence of length 1161, rather than 12. Establishing this took a computer nearly 6 hours and generated a 13-gigabyte file detailing its working. The pair compare this to the size of Wikipedia, the text of which is a 10-gigabyte download. It is probably the longest proof ever: it dwarfs another famously huge proof, which involves 15,000 pages of calculations.

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## Nanospiked bacteria are the brightest hard X-ray emitters discovered, 10,000 fold amplification effect

In a step that overturns traditional assumptions and practice, researchers at the Tata Institute of Fundamental Research, Mumbai and Institute for Plasma Research, Gandhi Nagar have fashioned bacteria to emit intense, hard x-ray radiation.

When one thinks of hard x-rays and bacteria it is usually that the bacteria are at the receiving end of the x-ray source - being imaged, irradiated for some modification or simply assessed for radiation damage. One hardly thinks of using bacteria as a source of x-rays, far from turning them into the brightest among such sources.

The experiment consists of a femtosecond, infrared, high intensity laser irradiating a glass slide coated with E. coli bacterial cells, turning the cell material into a hot, dense plasma. Laser driven plasmas have been known to be very useful table top x-ray sources and efforts are constantly being made to improve their brightness.

One such effort, an important one, has been to create plasmas on a nanostructured surface where the nanostructure amplifies the incident intensity by electromagnetic local field enhancement. The present advance has been made possible by the insight the researchers had when they realized that natural micro and nanostructures in the bacteria can be readily used for such intensity enhancement leading to hotter, brighter plasma. They showed that the bacterial cells increased the x-ray flux by a factor of 100 in the 50 - 300 keV x-ray region [1]. Further they grow the bacterial cells in a silver chloride solution whereby the silver atoms aggregated as nanoparticles inside the cell. They could then use these bacteria spiked with nanoparticles to boost the emission another 100 times, leading to an overall enhancement of 10,000 times from the flux emitted by plain glass slides without the bacterial coating [1]. This is the highest conversion of laser light to hard x-rays ever achieved.

This lateral stride could potentially lead to biologically inspired plasma physics and high energy density science with myriad applications among novel particle sources, creation of extreme excited states and related areas.

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## A fleet of autonomous taxis could dramatically slash vehicle emissions, study suggests

Whenever we hear the latest buzz about driverless vehicles — like the ones currently in development by Google — one of the first benefits brought up is safety. The gist is that the vast majority of car accidents are the result of human error, and taking the human out of the equation would thus make streets a lot safer.

But that’s hardly the only benefit, suggests a new study in Nature Climate Change by Jeffrey Greenblatt and Samveg Saxena of the Lawrence Berkeley National Laboratory. The researchers model a future in which electric-powered driverless cabs or “autonomous taxis” roam the streets, in a range of sizes and specifically tasked to pick up a matching number of passengers for a given ride.

Autonomous taxis are anticipated to be deployed according to each trip’s occupancy need (‘right-sizing’) because it is cost-effective for owners (capital and operating costs are lower) and passengers (who pay only for needed seats and storage),” the authors write. Smaller vehicles will save energy, and moreover, the authors project, there will be additional efficiency gains from two sources. These vehicles will be more likely to be electric, and thus powered from an increasingly renewable energy source; and they will travel considerably more miles per year,  meaning that more miles will be clean-powered.

It all adds up to a strong business case, meaning the vehicles would be “likely to gain rapid early market share.” The result is that by the year 2030, autonomous taxis could be dramatically cleaner not only than current cars, but also than projected hybrids in that year. The emissions reduction over cars we currently drive would be 87 to 94 percent, Greenblatt and Saxena find, and over future hybrids would be 63 to 82 percent.

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## Quantification of aging in young adults - Aging rates vary widely, study shows

A study of people born within a year of each other has uncovered a huge gulf in the speed at which their bodies age. The report, in Proceedings of the National Academy of Sciences, tracked traits such as weight, kidney function and gum health. Some of the 38-year-olds were ageing so badly that their "biological age" was on the cusp of retirement. The team said the next step was to discover what was affecting the pace of aging.

The international research group followed 954 people from the same town in New Zealand who were all born in 1972-73. The scientists looked at 18 different ageing-related traits when the group turned 26, 32 and 38 years old. The analysis showed that at the age of 38, the people's biological ages ranged from the late-20s to those who were nearly 60.

"They look rough, they look lacking in vitality," said Prof Terrie Moffitt from Duke University in the US. The study said some people had almost stopped aging during the period of the study, while others were gaining nearly three years of biological age for every twelve months that passed. People with older biological ages tended to do worse in tests of brain function and had a weaker grip. Most people's biological age was within a few years of their chronological age. It is unclear how the pace of biological ageing changes through life with these measures.

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## Dengue Fever Virus is Rapidly Evolving

Scientists have been looking at dengue fever and they have concluded that the virus that causes the disease is capable of rapid evolution. This means finding ways to kill the virus is a very challenging task.

Dengue virus is prevalent in some 100 countries worldwide and the signs are that the disease is spreading to more territories. By spreading the genetic diversity of the virus has increased, meaning that the hunt for effective counter drugs becomes more difficult.

Dengue fever is a disease, spread by mosquitoes, that affects over 50 million people a year. The disease manifests as fever, headache, muscle and joint pains, accompanied by a skin rash. In some cases fatal dengue hemorrhagic fever can result, causing internal bleeding.

A researcher at Duke-NUS called Eng Eong Ooi has recently found a new strain of dengue, called serotype 2 virus (DENV-2). This stain has evolved from and replaced another form of the virus that was common during the 1990s, in Puerto Rico. The dengue virus has four known serotypes (DENV1-4) circulating in nature.

The virus was able to make this genetic transformation due to three mutations that have been discovered in the tail of the dengue viral genome. Through these mutations the viral strain was able to suppress the human antiviral response. This allowed the newly emerging strain to spread, infect more mosquitoes and thus infect more people.

The study is important because it provides a new understanding as to how the virus mutates and this insight might offer ways to combat the virus. Studying the virus at the genetic level also provides information about which stains of the virus are most likely to trigger epidemics. This information is useful in dengue surveillance.

The research has been published in the journal Science (“Dengue subgenomic RNA binds TRIM25 to inhibit interferon expression for epidemiological fitness.”)

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## Mortality Gap: Have Women Always Lived Longer than Men?

In every single country on the planet, women live longer than men. In response to this unpleasant fact, men are fond of replying, "That's because we have to put up with women." Humorous though it may be, that's not the actual reason women live longer than men. In fact, it wasn't until the beginning of the 20th Century that the "mortality gap" between men and women became so striking.

To investigate the underlying reason for the gender gap in life expectancy, a team of researchers examined mortality data for people born between 1800 and 1935 in 13 developed countries. Using this data, they were able to determine changes in the male-female mortality ratio, as well as determine when and why women began to outlive men.

In the figure above, each birth cohort is represented by a single colored line. For example, people born between 1800 and 1819 are represented by 20 different lines, each of which is colored black; people born between 1920 and 1935 are represented by 16 colored lines, each of which is colored red. The chart plots age on the X-axis (i.e., "age at time of death") against the male-female mortality rate ratio on the Y-axis.

The figure shows that the relative mortality rate for men gets worse in subsequent years. Compare the mortality rates at age 60, for instance. The mortality rate ratio for people born between 1800 and 1839 (black and gray lines) hovers roughly around 1.2; that means that about 120 men died for every 100 women who died at age 60. Just a few decades later, a dramatic shift occurs: the male-female mortality rate ratio for people born between 1880 and 1899 (green lines) skyrockets to 1.6, meaning that 160 men died for every 100 women who died at age 60. Then it goes from bad to worse. For the 1920-1935 birth cohort, the ratio is a shocking 2.1 at age 60, meaning that 210 men died for every 100 women.

Why is this the case? The authors' analysis suggests two major factors: The first is smoking, which is more common among men. (With smoking factored out, the pattern of an increasing male-female mortality ratio still persists but to a lesser extent, as shown above.) The second is cardiovascular disease, a condition to which men seem to be more vulnerable than women. This may be due to gender differences in diet, lifestyle, and even genetics. Indeed, the researchers found that cardiovascular disease was the major factor causing excess deaths among men as compared to women.

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## Better, Stronger, Faster: The Future of the Bionic Body

In the future, a woman with a spinal cord injury could make a full recovery; a baby with a weak heart could pump his own blood. How close are we today to the bold promise of bionics—and could this technology be used to improve normal human functions, as well as to repair us? Join Bill Blakemore, John Donoghue, Jennifer French, Joseph J. Fins, and P. Hunter Peckham at "Better, Stronger, Faster," part of the Big Ideas Series, as they explore the unfolding future of embedded technology.
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## The U.S. just recorded its first confirmed measles death in 12 years

[Everything you need to know about measles]

Health officials on Thursday confirmed the country's first measles death since 2003, and they believe the victim was most likely exposed to the virus in a health facility in Washington state during an outbreak there.

The woman died in the spring; a later autopsy confirmed that she had an undetected measles infection, the Washington State Department of Health said in a statement. The official cause of death was announced as "pneumonia due to measles."

The woman was at a Clallam County health facility "at the same time as a person who later developed a rash and was contagious for measles," the health department statement read. "The woman had several other health conditions and was on medications that contributed to a suppressed immune system. She didn’t have some of the common symptoms of measles such as a rash, so the infection wasn’t discovered until after her death."

The release did not provide any other identifying details, including the woman’s age. According to the U.S. Centers for Disease Control and Prevention, 178 people from 24 states and the District were reported to have measles from Jan. 1 through June 26 of this year. Two-thirds of the cases, the CDC noted, were "part of a large multi-state outbreak linked to an amusement park in California."

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## Human eye-like structure discovered in single-celled plankton: Mitochondria, plastids evolved together

Scientists have peered into the eye-like structure of single-celled marine plankton called warnowiids and found it contains many of the components of a complex eye.

The single-cell marine plankton, a predatory microbe, bears a dark purple spot known as an ocelloid. It resembles the multicellular eye of animals so much that it was originally mistaken for part of an animal the warnowiids had eaten.

Canadian Institute for Advanced Research senior fellows Brian Leander and Patrick Keeling supervised lead author Greg Gavelis at the University of British Columbia and, in collaboration with senior fellow Curtis Suttle, showed that this eye-like structure contains a collection of sub-cellular organelles that look very much like the lens, cornea, iris and retina of multicellular eyes that can detect objects -- known as camera eyes -- that are found in humans and other larger animals.

The researchers gathered single cells of warnowiids off the coasts of B.C. and Japan, sequenced their genomes, and analyzed how the eyes are built using new methods in electron microscopy that allow the reconstruction of three dimensional structures at the subcellular level.

They found that a layer of interconnected mitochondria, organelles that supply energy to cells, surrounds a robust lens and makes up the warnowiids's equivalent of a cornea. In addition, a network of interconnected plastids that originated from an ancient symbiosis with red alga radiate from the retinal body.

Plastids have their own genome and are responsible for harvesting energy from light in photosynthetic plants and algae. The scientists determined that the retinal body contains a plastid genome suggesting components of the light-harvesting machinery may have been adapted to use in detecting light for sensory functions rather than to acquire energy.

Scientists still don't know exactly how warnowiids use the eye-like structure, but clues about the way they live have fuelled compelling speculation. warnowiids hunt other dinoflagellates, many of which are transparent. They have large nematocysts, which Leander describes as "little harpoons," for catching prey. And some have a piston -- a tentacle that can extend and retract very quickly -- with an unknown function that might be used for escape or feeding.
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## Bristol researchers gain new insight into a human visual supersense

An experiment originally designed to test the visual abilities of octopuses and cuttlefish has given University of Bristol researchers an unprecedented insight into the human ability to perceive polarized light – the supersense that most of us don’t even know we have.

We are all familiar with colour and brightness, but there is a third property of light, the ‘polarization’, which tells us the orientation in which the light waves are oscillating. Dr Shelby Temple, a Research Associate from the Ecology of Vision Group in Bristol’s School of Biological Sciences and one of the study’s lead authors said: “Imagine a skipping rope represents a light wave travelling through space.  If you move the rope from side to side, the wave you make is horizontally polarized.  If you shake the rope up and down you create a vertically polarized wave. Generally, light is a mixture of polarizations, but sometimes – for example in parts of the sky, on your computer screen and in reflections from water or glass – a large percentage of the waves are oscillating in the same orientation and the light is strongly polarized.”

Animals, like bees and ants, use polarization patterns in the sky as a navigation aid.  But few, even in the scientific community, are aware that humans can perceive the polarization of light with the naked eye too.  We do so using ‘Haidinger’s brushes’, a subtle visual effect, which appears like a yellow bow tie at right angles to the polarization angle.

In the present study, the researchers developed special filters to vary the percentage of polarized light from 0 to 100 per cent and tested the minimum percentage polarization at which Haidinger’s brushes could be detected.  Among 24 people, the average polarization sensitivity threshold was 56 per cent.  Some people could still see Haidinger’s brushes when the light was less than 25 per cent polarized – not quite as good as cuttlefish but still better than any other vertebrate tested to date.

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## Three year clinical trial has recently been completed for bionic eye retinal implants

The experimental device, known as the Argus II, functions to improve the vision in people blinded by retinitis pigmentosa. RP is an inherited, degenerative eye disease that causes severe vision impairment. The Argus II restores low levels of vision in functionally blind patients.

The device works by using a microscopic video camera, located in the glasses of the patient. The device sends collected information to a special processing unit. The unit then converts the signals to an electronic device implanted into the patient’s retina.

Trials were conducted on 30 subjects in 10 centers in the United States and Europe. Tests showed that 89 percent of the subjects in a trial reported that they received strong images when using the device. Further tests are continuing, based on the very promising results. The Argus II has a unit cost of around \$100,000.

The experimental device, known as the Argus II, functions to improve the vision in people blinded by retinitis pigmentosa. RP is an inherited, degenerative eye disease that causes severe vision impairment. The Argus II restores low levels of vision in functionally blind patients.

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## Fairy Lights in Femtoseconds: Scientists have created a hologram that can be touched

Hologram technology already exists. Whatever is not yet sufficiently advanced, however, we have witnessed some progress in this area as: hologram created in mid air by laser, 3D hologram displays, holograms in the toy industry and the like. Unfortunately Hologram display can not be touched and interaction with it would feel more natural.

That at least was true till now when a Japanese team of scientists from Digital Nature Group managed to create a hologram display that you can touch. The concept is similar to the hologram which was created in mid air (also in Japan). Namely, the laser is used to create display emits superfast and supershort radiation (measured in femtoseconds). These radiations wiggle molecules of air, while helping to ionize (resulting in their lighting). As we know, a set of ionized particles to a place called plasma, which is generated by the laser.

The very fact that the molecules are forced to move in the air is causing the ability to touch them. Namely, when you put a finger in the hologram air, molecules are hitting your skin and you feel like it you touched something. According to lead author of the study it feels like you're touching sand paper or electrostatic shock. Additionally, by using a camera which is placed under the display you can recognize when you touched the display and where, and to convey the command somewhere in the software.

Scientists say that they have chosen femtosecond display nanoseconds because it is safer for the skin because there is not enough time to warm up and damage. This will allow interactive 3D holograms that can be touched, which will contribute to significant progress in hologram technology. The projection of such holograms may allow upgrading of our reality in the case if these kind of devices are placed all around us and project images and objects that we could touch.

This femtosecond laser-based volumetric display will be demonstrated to the public as a part of the Siggraph 2015 exhibition in August.

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## Inside a Lizard's Regenerating Tail

Researchers created visual and DNA analysis of how anoles regenerate their tails.

ANOLES ARE CURIOUS little lizards capable of ditching their tails when they feel threatened. This self-amputation, called autotomy, takes about 25 days for the tail to regrow. A paper published today in the open-access online journal PLOS ONE describes the genetic process anoles use to regenerate. The researchers created the above graphic as a visual aid in their genetic sequencing. These ultra-thin slices of tail were taken from euthanized anoles at progressive stages of regeneration. This is very sad, but their sacrifices may someday help humans learn how to regenerate, too.

For the first 10 days, the lizard’s tail heals similarly to any other wound—new blood vessels form, and epithelial tissue (the soft, white skin under a scab) closes the gap over raw flesh. Then the tail starts to regrow, beginning with nerve tissue from the spinal cord (days 10-15), soft muscle, and tissue for transporting fluids. By day 20, the muscular tissue is starting to firm up around a cartilaginous tube that will eventually harden, and segment into tail bones. The far right of the image shows a 25-day-old tail. The lower-case ‘m’ indicates strong muscle fibers capable of quick motor control—the anole can flick its new tail. Interestingly, regeneration is very different from the way embryonic anoles grow their tails, where segments of bone and muscle are formed early.

The main thrust of the paper was figuring out which genes anoles uses to regenerate. DNA is a library of an organisms genes contained in every cell, and RNA is the enzyme that activates those genes when and where they are needed. The researchers used a technique called transcriptomic analysis to figure out which genes the anoles were using at different parts of the tail during different times in the regeneration process. In all, they identified 326 genes.

Most other regenerating animals, like zebrafish and newts, inherited their ability from an ancestor they don’t share with mammals. Anoles though, are more closely related to us than fish and amphibians. In fact, 302 of the 326 genes the researchers identified have homologs (similar genes) in mammal DNA. These genes could put scientists closer figuring out how to regrow limbs in humans.

LEONARDO WILD's curator insight,

Truth is like a lizard, the moment you have it in your hands, it will run away and grow a new one in a twinkling. (Paraphrasing words that  Ivan Turgenev wrote to Leo Tolstoy (1856)).

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## Stanford high-speed video reveals how parrots keep a clear line of sight during acrobatic flight

Engineers looking for inspiration for better drone camera design might want to set their gaze toward lovebirds. Lovebirds are famous for their ability to quickly maneuver through densely cluttered airspace, and Stanford engineers now show that this is likely made possible by the birds' ability to turn their heads at a speed that is tops in the animal world.

"During rapid flight through densely cluttered forests every split second counts. Having more time to see and react to your environment gives you an edge in making the right decision," said David Lentink, an assistant professor of mechanical engineering at Stanford. "Clearly, there are evolutionary benefits for behaviors that help avoid crashing in complex environments."

Lentink and his colleagues used stereo high-speed cameras to film the birds as they took off and performed a rapid turning maneuver before landing on the initial perch. Analysis of the stereo videos showed that the birds could turn their heads at speeds reaching 2,700 degrees per second, as fast as insects, and orient to a new target with incredible accuracy.

"They are almost four times faster than humans at solving a similar visual task," said Daniel Kress, a postdoctoral fellow in Lentink's lab and first author on the research paper. "Basically, if lovebirds could spin their head a full 360 degrees, they could do it so fast that it would go unnoted by a blinking human."

The work could inform the design of drone vision systems in a couple of ways. The researchers noticed that the birds only began turning their heads during the end of the wing downstroke, maximizing the length of time that their line of sight would be unobscured. The research suggests that rotating the camera gimbal on a drone faster during a turn could improve visual quality.

"If drone gimbals would be as fast as the neck of a lovebird, making a saccade of 60 degrees in about 40 milliseconds, they would be able to reorient the camera in a single frame, since typical drone cameras operate at about 30 frames per second," Lentink said. "With only one frame blurred, the videos would essentially be free from blur due to camera movement, even during dramatic maneuvers."

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## Ocean acidification study calls for 'immediate and substantial' reduction of CO2 emissions

The oceans play a key role in absorbing carbon dioxide, but international climate talks have only "minimally considered" the impact the gas is having as it turns these bodies of water acidic, scientists say in a new study.

More than 20 marine scientists worked to analyze two potential futures.

One involves meeting the target set out by the UN-established Intergovernmental Panel on Climate Change (IPCC) of limiting the rise in global warming to 2 C through CO2 cuts (the RCP2.6 scenario). The other (RCP8.5) reflects the current trajectory of business-as-usual CO2 emissions.

The study, published last week in the journal Science, calls for negotiators at climate talks to stress the impact CO2 is having on ocean acidification.

They say their goal is to speak directly to policymakers, adding the study has the backing of the Oceans 2015 Initiative.

That group of experts says that each day, more than a quarter of the carbon dioxide emitted by human activity is absorbed by the oceans. Without this dynamic, the effects of climate change would be far greater.

By 2100, scientists predict that the oceans' pH level will have fallen by 0.4 units — or an increase of 150 per cent in ocean acidity — compared to its mid-19th-century level. That corresponds to a three-fold increase in the water's acidity.

Acidification makes it more difficult for marine animals to produce skeletons and shells, and puts the essential ocean habitat, coral reefs, at risk of eroding faster than they can be rebuilt.

pdeppisch's comment, Today, 1:23 PM
I don't think meaningful CO2 reduction will happen any time soon! We are headed for "big time" trouble! Humanity usually only acts after catastrophe! It will be the same here. The planet will survive! Humanity will survive! And humanity will be back in the stone age!
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## Brain Imaging Shows How Children Inherit Their Parents' Anxiety

In rhesus monkey families – just as in their human cousins – anxious parents are more likely to have anxious offspring. And a new study in an extended family of monkeys provides important insights into how the risk of developing anxiety and depression is passed from parents to children.

The study from the Department of Psychiatry and the HealthEmotions Research Institute at the University of Wisconsin-Madison shows how an over-active brain circuit involving three brain areas inherited from generation to generation may set the stage for developing anxiety and depressive disorders.

The study is being published today in the Proceedings of the National Academy of Sciences (PNAS). It shows that elevated activity in this prefrontal- limbic -midbrain circuit is likely involved in mediating the in-born risk for extreme anxiety, anxious temperament that can be observed in early childhood.

“Over-activity of these three brain regions are inherited brain alterations that are directly linked to the later life risk to develop anxiety and depression,” says senior author Dr. Ned Kalin, chair of psychiatry at the UW School of Medicine and Public Health. “This is a big step in understanding the neural underpinnings of inherited anxiety and begins to give us more selective targets for treatment.”

Previous research by Kalin’s group has shown that anxious temperament is inherited, and explained the brain circuits involved. About half of children who show extreme anxiety go on to develop stress-related psychiatric disorders later in life.

Monkeys, like humans, can be temperamentally anxious and pass their anxiety-related genes on to the next generation. By studying nearly 600 young rhesus monkeys from a large multi-generational family, Drs. Andrew Fox, Kalin, and colleagues found that about 35 percent of variation in anxiety-like tendencies is explained by family history.

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## Rescuing memory: Blocking beta2-microglobulin could stop memory loss at old age

There might be a way to stave off the memory loss people experience as they get older. As people age, a protein that disrupts brain cell repair gradually builds up in the blood and cerebrospinal fluid. The offending protein, called beta2-microglobulin (B2M), has now been shown to affect how mice perform in memory tests. Work is already under way to identify drugs that mop up or destroy B2M which will allow the researchers to test if the same applies to humans. If so, the same drug could offer a solution.

"Right now, the idea is to develop antibodies or small molecules that can either block the effects of the protein or help to remove it from old blood," says Saul Villeda of the University of California at San Francisco. Villeda's discovery is the first detailed investigation of a so-called "anti-elixir" factor, in other words one that builds up with age and causes brain degeneration. Most research aimed at reversing ageing so far has focused on "elixir" factors – agents that bring back lost youth. For example, when the the blood of young mice is injected into old mice, it halts brain and muscle degeneration, helps fractured bones heal and prevents heart damage.

B2M's main job is to help the immune system tell the difference between foreign cells and those from the body, but it also plays a role in development of the nervous system. When Villeda's team injected B2M into the brains or blood of young mice, they performed almost as badly as elderly mice on two kinds of memory test. When the molecule had been naturally eliminated from their bodies – around 30 days later - the animals' performances returned to normal, suggesting the effect of B2M is reversible.

Some mice had been genetically engineered so that they couldn't make B2M. These animals performed equally well regardless of age. "It may not be this factor alone that causes the memory loss," says Benjamin Alman of the Hospital for Sick Children in Toronto, Canada, who is trying to find molecules in young blood that heal bones faster. "But it does raise the possibility that failing memory can be rescued by drugs that interfere with these circulating factors," he says. "The concept is very exciting, and would have been unthinkable a few years ago."

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## The First Evidence for STDs in Honeybees

One of the most common parasites infecting honeybees is sexually-transmitted, a new study published to Scientific Reports finds. Nosema is a unicellular fungus that causes nosemosis, the most widespread disease of honeybees. Diseased bees are often afflicted with dysentery, disjointed wings, and an absent sting reflex, among many other symptoms.

The most common way Nosema is passed is via spore-ridden fecal matter. Bees swallow the spores, which make their way to the insects' guts and germinate. But it turns out that spores can also get into the semen of male bees, and when these bees copulate with the queen, she can also become infected.

Researchers primarily based out of the University of Leeds collected sexually mature male bees from 39 colonies infested by Nosema. They then harvested the insects' semen (very delicately, as one would surmise) and inseminated a group of queens. One out of every five of the queens developed nosemosis.

Luckily for the colony, infected queens do not pass Nosema onto their young. None of the 400 eggs laid by queens in the experiment carried the parasite. However, unluckily for parasite-ridden queens, their days are usually numbered once they take on the parasite. An infected queen's ovaries quickly degenerate, severely reducing her egg-laying capacity. Sensing the queen's infertility, workers then set about rearing replacement queens. When one is ready to take the throne, workers encircle the old queen and sting her to death.

"The results provide the first quantitative evidence of a sexually transmitted disease (STD) in social insects," the researchers said of the study. STDs have been found in insects before, though, unlike vertebrate STDs, which are commonly caused by bacteria or viruses, insect STDS are usually caused by parasites -- mites, nematodes, fungi, and protists.

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 Rescooped by Dr. Stefan Gruenwald from Melanoma BRAF Inhibitors Review

## New Treatment for Melanoma Uses a Form of the Herpes Virus

The American Cancer Society estimates that about 74,000 Americans will be diagnosed with melanoma this year and almost 10,000 will die from this deadliest form of skin cancer. Over the past several years, treatment of advanced cases of melanoma has been transformed as new FDA-approved therapies developed by several different companies have come onto the market. An FDA advisory committee recently approved a therapy that takes a totally novel approach that involves injecting a live attenuated virus directly into regionally or distant metastatic melanoma tumors.

HSV-1 infections cause cold sores and sometimes genital herpes, although infection with human simplex virus 2 is more often the cause of genital herpes. Researchers have characterized the virulence genes of the virus. Talimogene laherparepvec, sometimes shortened to T-VEC, is made by depleting those virulence genes and inserting sequences that generate GM-CSF. It’s believed that removal of the virulence genes decreases the chances that the virus will infect nerve cells and will instead home in on tumor cells. By delivering GM-CSF, the genetically engineered virus enhances tumor antigen presentation to the immune system and induction of immune system attack on the malignancy.

Encouraging durable response results

Talimogene laherparepvec was studied in a randomized, open label phase 3 study to compare the new therapy with GM-CSF injections in subjects with unresectable stage IIIB, IIIC, and IV melanoma. A total of 437 subjects were randomized into the study at 64 study sites. The study was designed to demonstrate an improvement in durable response rate, which was defined as a complete response or partial response maintained for at least six months. Subjects were to receive therapy until Week 24, even if their melanoma was progressing. GM-CSF was used for comparison purposes because at the time that this study was designed, it was also in clinical studies as a treatment for melanoma. It is unclear, though, if GM-CSF by itself has any therapeutic value.

To be enrolled in the study, people had to be age 18 or older, have a histologically confirmed malignant melanoma of the stages listed in the previous paragraph, measurable disease of at least 1 cm, injectable disease (either on the surface of the skin or through the use of ultrasound guidance), ECOG performance of 0 or 1, and a life expectancy greater than four months from date of randomization. The study exclusions included active cerebral disease, any bone metastases, history of secondary cancer unless disease-free for at least five years, open herpetic skin lesions, and primary ocular or mucosal melanoma.

Via Krishan Maggon
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## Babies Can Form Abstract Relations Before They Even Learn Words

According to a new study published in the journal Child Development, infants are capable of understanding abstract relations like ‘same’ and ‘different.’

“This suggests that a skill key to human intelligence is present very early in human development, and that language skills are not necessary for learning abstract relations,” said Dr Alissa Ferry of the Scuola Internazionale Superiore di Studi Avanzati in Italy, lead author of the study.

To trace the origins of relational thinking in infants, Dr Ferry and her colleagues from Northwestern University tested whether 7-month-old infants could understand the simplest and most basic abstract relation – the same-different relation.

Infants were shown pairs of items that were either the same (two Elmo dolls) or different (Elmo doll and a toy camel) until their looking time declined.

In the test phase, the infants looked longer at pairs showing the novel relation, even when the test pairs were composed of new objects. That is, infants who had learned the same relation looked longer at test pairs showing the different relation during test, and vice versa.

This suggests that the infants had encoded the abstract relation and detected when the relation changed. “We found that infants are capable of learning these relations. Additionally, infants exhibit the same patterns of learning as older children and adults – relational learning benefits from seeing multiple examples of the relation and is impeded when attention is drawn to the individual objects composing the relation,” Dr Ferry said.

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## Nationwide study measures short-term spike in July 4 particulate matter due to fireworks

From our nation's founding, the Fourth of July has been synonymous with fireworks. While many grew up learning that fireworks can be dangerous to the eyes and hands if not handled properly, fireworks also produce air pollutants, including particulate matter, that are linked to short-term or long-term health effects.

NOAA scientist Dian Seidel and Abigail Birnbaum, a student intern at NOAA, have authored a new study appearing in the journal Atmospheric Environment that quantifies the surge in fine particulate matter -particles that are two and one half microns in diameter (PM2.5) -on July 4, using observations from the 315 U.S. air quality monitoring sites that operated from 1999 to 2013. While scientists have known that fireworks displays produce a surge in fine particulates, the new study is the first nationwide quantitative analysis of the effects.

"We chose the holiday, not to put a damper on celebrations of America's independence, but because it is the best way to do a nationwide study of the effects of fireworks on air quality," said Seidel, a senior scientist at NOAA's Air Resources Laboratory in College Park, Maryland. "These results will help improve air quality predictions, which currently don't account for fireworks as a source of air pollution. The study is also another wake up call for those who may be particularly sensitive to the effects of fine particulate matter."

PM2.5 are microscopic particles that can affect health because they travel deep into a person's respiratory tract, entering the lungs. Both long- and short-term exposures to fine particles are linked to a range of health effects - from coughing, wheezing and shortness of breath, to asthma attacks, heart attack and stroke, and premature death in people with heart or lung disease. People with heart or lung disease, older adults, and children are among those most at risk from particle pollution exposure. For more information on risks, go online to the Environmental Protection Agency at: http://www.epa.gov/airquality/particlepollution/2012/decfshealth.pdf

The new research shows that hourly concentrations of fine particulate matter typically reach their highest levels, when compared to the days before and after July 4, on the evening of July 4. Levels drop back down by noon on July 5, according to the research. On average, the increases are largest from 9-10 p.m. on the holiday. Average concentrations over the 24-hour period starting at 8 p.m. on July 4 are 42 percent greater than on the days preceding and following the holiday.

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## First trial of gene therapy for cystic fibrosis to show beneficial effect on lung function

For the first time gene therapy for cystic fibrosis has shown a significant benefit in lung function compared with placebo, in a phase 2 randomised trial published in The Lancet Respiratory Medicine journal. The technique replaces the defective gene response for cystic fibrosis by using inhaled molecules of DNA to deliver a normal working copy of the gene to lung cells.

“Patients who received the gene therapy showed a significant, if modest, benefit in tests of lung function compared with the placebo group and there were no safety concerns,” said senior author Professor Eric Alton from the National Heart and Lung Institute at Imperial College London. “Whilst the effect was inconsistent, with some patients responding better than others, the results are encouraging.” [1]

Cystic fibrosis is a rare inherited disease caused by mutations in a single gene called cystic fibrosis transmembrane conductance regulator (CFTR) and affects 1 in every 2500 newborns in the UK and over 90000 people worldwide. Scientists have discovered around 2000 CFTR mutations so far. These mutations make the lining of the lungs secrete unusually thick mucus. This leads to recurrent life-threatening lung infections, which result in lung damage that causes 90% of deaths in people with cystic fibrosis.

Since the discovery of the genetic basis for cystic fibrosis in 1989, scientists have developed a variety of viral and non-viral vector systems for delivering a corrected CFTR gene back into lung cells.  Despite expectations of a rapid breakthrough, no cystic fibrosis gene therapy trial so far has been able to show long-term clinical improvement.

Coordinated by the UK Cystic Fibrosis Gene Therapy Consortium [2], the two-year study involved 136 CF patients aged 12 years or older from across the UK. Participants were randomly assigned to either 5ml of nebulised (inhaled) pGM169/GL67A (gene therapy) or saline (placebo) at monthly intervals over 1 year. Lung function was evaluated using a common clinical measure of the volume of air forcibly exhaled in one second (FEV1).

After a year of treatment, in the 62 patients who received the gene therapy, FEV1 was 3.7% greater compared to placebo [3]. This was a result of stabilisation of respiratory function rather than an improvement. However, the effects were inconsistent, with some patients responding better than others. In particular, in the half of patients with the worst lung function at the start of the study, there was a doubling of the treatment effect, with changes in FEV1 of 6.4%.
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## A colloidal quantum dot spectrometer that fits on your cell phone and let you scan for skin cancer

We use them to spy on exoplanets, diagnose skin-cancer, and ID the makeup of unknown chemicals. They're on NASA spacecraft flying around Saturn's moons right now. Yes, right alongside the microscope, the optical spectrometer—an instrument that breaks down the light that something reflects or emits, telling you what its made of—is one of the most ubiquitous tools in all of science. Today, Jie Bao, a physicist at Tsinghua University in Beijing, China, has just discovered a fascinating way to make them smaller, lighter, and less expensive than we ever thought possible.

By using tiny amounts of strange, light-sensitive inks, Bao and his colleague Moungi Bawendi—a chemist at MIT—have designed a working spectrometer that's small enough to fit on your smartphone. Because of the tool's simple design and its need for only an incredibly small amount of the inks, Bao says, his spectrometer only requires a few dollars worth of materials to make. They report the research today in the journal Nature.

"Of course we still have a lot of room for improvement. But performance-wise, even at this preliminary stage, our spectrometer works very close to what's currently being sold in the market," Bao says. "I think that's one of the most attractive results of our research: This spectrometer is already so close to a real product."

As if making micro-sized stained glass windows, Bao prints a tiny grid of 195 different-colored liquid inks directly onto a flat sensor. (That sensor, called a CCD sensor, is what your phone's camera uses to pick up light.) Each of the 195 windows is made of a material called colloidal quantum dots, and each "absorbs certain wavelengths of light, and lets others go," says Bao. When light hits each window and travels through, the underlying sensor records how the light changed. Later, a computer can compare the data from all of the windows and reconstruct what wavelengths made up the original light.

Right now, Bao's spectrometer is about the size of a quarter, and he says the underlying CCD sensors he uses can be bought online for less than a dollar a pop. Because he's using just a tiny drop of each of the colloidal quantum dot inks (which have only recently been developed) the cost all 195 drops is only on the order of a few dollars.

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## Underwater farmers grow strawberries in balloon gardens

This is a snapshot of life at one of the world's strangest farms. In the eerie blue light, a diver drifts between underwater greenhouses, where the first seeds of the year – basil, strawberry, lettuce and beans – were planted last week. The transparent "biospheres" beneath the Bay of Noli, in Savona, Italy, are part of the three-year-old Nemo's Garden project, which aims to find innovative ways of growing crops in places that lack freshwater or fertile soil.

Resembling large balloons, the air-filled structures are anchored to the sea floor and float between 5 and 10 meters below the surface. Inside, water condenses on the roof of the spheres, dripping back down to keep the plants watered, while the warm, near-constant sea temperature nurtures the plants.

The site is equipped with four cameras that stream back live video, allowing the unusual farmers to be watched in action online. Sensors collecting live data can also be monitored from a website, revealing for example the humidity and air temperature in the greenhouses. It's not the only unlikely garden around. An island of green was built in the middle of a sea of garbage in Djenné, Mali.

Lorraine Chaffer's curator insight,
Innovative ideas for future food production?
Eric Larson's curator insight,

One way to grow strawberries.

 Scooped by Dr. Stefan Gruenwald

## Why human egg cells don't age well

When egg cells form with an incorrect number of chromosomes--a problem that increases with age--the result is usually a miscarriage or a genetic disease such as Down syndrome. Now, researchers at the RIKEN Center for Developmental Biology in Japan have used a novel imaging technique to pinpoint a significant event that leads to these types of age-related chromosomal errors. Published in Nature Communications, the study shows that as egg cells mature in older women, paired copies of matching chromosomes often separate from each other at the wrong time, leading to early division of chromosomes and their incorrect segregation into mature egg cells.

Most cells have two copies of each chromosome--one from each parent. Immature egg cells begin this way, but are transformed through a process called meiosis into mature egg cells that only have one copy of each chromosome. At the beginning of meiosis each chromosome copies itself and joins with its matching pair to form a group of four chromosomes that swap genetic material.

These groups of four chromosomes--called bivalents--then split apart into single pairs, and the cell divides. One part continues as the egg cell and the other part degrades. In the second stage of meiosis, the single pairs of chromosomes--two sister chromatids joined in the middle--separate and the egg cell divides again in the same way, leaving a single mature egg cell with one copy of each chromosome.

"What we found," explains team leader Tomoya Kitajima, "is that in older cells, the bivalents sometimes separate early, and this leads to division of sister chromatids in the first stage of meiosis, rather than in the second stage."

To determine the most common type of age-related segregation errors, the researchers first used a novel high resolution imaging technique to visualize chromosomes in live mouse egg cells throughout the whole first stage of meiosis. They found that chromosomes were always distributed correctly in young egg cells, but that a little less than 10% of older cells suffered from segregation errors. Closer examination of the chromosome-tracking data showed that the dominant type of error was predivision of sister chromatids, and not movement of intact chromosome pairs to only one of the new cells.

The tracking data also allowed researchers to go back in time and look at what was happening to chromosomes that eventually segregated incorrectly. They found that a large majority of them had been part of bivalents whose connection between paired chromosome copies had become hyperstretched and then snapped earlier in meiosis, leaving single pairs.
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## External magnetic field controlled, nanoscale bacteria-like robots could replace stents and angioplasty balloons

Swarms of microscopic, magnetic, robotic beads could be used within five years by vascular surgeons to clear blocked arteries. These minimally invasive microrobots, which look and move like corkscrew-shaped bacteria, are being developed by an \$18-million, 11-institution research initiative headed by the Korea Evaluation Institute of Industrial Technologies (KEIT).

These “microswimmers” are driven and controlled by external magnetic fields, similar to how nanowires from Purdue University and ETH Zurich/Technion (recently covered on KurzweilAI) work, but based on a different design. Instead of wires, they’re made from chains of three or more iron oxide beads, rigidly linked together via chemical bonds and magnetic force. The beads are put in motion by an external magnetic field that causes each of them to rotate. Because they are linked together, their individual rotations cause the chain to twist like a corkscrew and this movement propels the microswimmer. The chains are small enough­­ — the nanoparticles are 50–100 nanometers in diameter — that they can navigate in the bloodstream like a tiny boat, Fantastic Voyage movie style (but without the microscopic humans) via a catheter to navigate directly to the blocked artery, where a drill would clear it completely.

Drilling through plaque:

The inspiration for using the robotic swimmers as tiny drills came from the Borrelia burgdorferi bacteria (shown above), which causes Lyme’s Disease and wreaks havoc inside the body by burrowing through healthy tissue. Its spiral shape enables both its movement and the resultant cellular destruction. By controlling the magnetic field, a surgeon could direct the speed and direction of the microswimmers. The magnetism also allows for joining separate strands of microswimmers together to make longer strings, which can then be propelled with greater force.

Once flow is restored in the artery, the microswimmer chains could disperse and be used to deliver anti-coagulant medication directly to the effected area to prevent future blockage. This procedure could supplant the two most common methods for treating blocked arteries: stenting and angioplasty. Stenting is a way of creating a bypass for blood to flow around the block by inserting a series of tubes into the artery, while angioplasty balloons out the blockage by expanding the artery with help from an inflatable probe.

“Current treatments for chronic total occlusion are only about 60 percent successful,” said MinJun Kim, PhD, a professor in the College of Engineering and director of the Biological Actuation, Sensing & Transport Laboratory (BASTLab) at Drexel University. “We believe that the method we are developing could be as high as 80–90 percent successful and possibly shorten recovery time. The microswimmers are composed of inorganic biodegradable beads so they will not trigger an immune response in the body. We can adjust their size and surface properties to accurately deal with any type of arterial occlusion.” Kim’s research was recently reported in the Journal of Nanoparticle Research.

Mechanical engineers at Drexel University are using these microswimmers as a part of a surgical toolkit being assembled by the Daegu Gyeongbuk Institute of Science and Technology (DGIST)Researchers from other institutions on the project include ETH ZurichSeoul National UniversityHanyang UniversityKorea Institute of Science and Technology, and Samsung Medical Center.

DGIST anticipates testing the technology in lab and clinical settings within the next four years.

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