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New study strengthens link between Arctic sea-ice loss and extreme winters

New study strengthens link between Arctic sea-ice loss and extreme winters | Amazing Science | Scoop.it

Declining Arctic sea-ice has made severe winters across central Asia twice as likely, new research shows. The paper is the latest in a series linking very cold winters in the northern hemisphere to rapidly increasing temperatures in the Arctic. But the long-term picture suggests these cold winters might only be a temporary feature before further warming takes hold.


Temperatures in the Arctic are increasing almost twice as fast as the global average. This is known as  Arctic amplification. As Arctic sea-ice shrinks, energy from the sun that would have been reflected away by sea-ice is instead absorbed by the ocean.


Arctic amplification has been linked with very cold winters in mid-latitude regions of the northern hemisphere. The UK, the US and Canada have all experienced extreme winters in recent years. Just last year, for example, the UK had its second-coldest March since records began, prompting the Met Office to call a  rapid response meeting of experts to get to grips with whether melting Arctic sea-ice could be affecting British weather.


The new study, published in Nature Geoscience, suggests the likelihood of severe winters in central Asia has doubled over the past decade. This vast region includes southern Russia, Mongolia, Kazakhstan, and northern China. And it's the Arctic that's driving the changes once again, the authors say.

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Droplets made to order

Droplets made to order | Amazing Science | Scoop.it
New method allows microdroplets of any shape to form on a surface.


Understanding liquid dynamics on surfaces can provide insight into nature’s design and enable fine manipulation capability in biological, manufacturing, microfluidic and thermal management applications. Of particular interest is the ability to control the shape of the droplet contact area on the surface, which is typically circular on a smooth homogeneous surface. A research team now shows the ability to tailor various droplet contact area shapes ranging from squares, rectangles, hexagons, octagons, to dodecagons via the design of the structure or chemical heterogeneity on the surface. They simultaneously obtain the necessary physical insights to develop a universal model for the three-dimensional droplet shape by characterizing the droplet side and top profiles. Furthermore, arrays of droplets with controlled shapes and high spatial resolution can be achieved using this approach. This liquid-based patterning strategy promises low-cost fabrication of integrated circuits, conductive patterns and bio-microarrays for high-density information storage and miniaturized biochips and biosensors, among others.

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Treating Ebola: The Hunt for a Drug

Treating Ebola: The Hunt for a Drug | Amazing Science | Scoop.it

Although there are currently no drugs or vaccines approved in the United States to treat or prevent Ebola, health officials have used several experimental drugs in the recent epidemic.


The World Health Organization has said that it is ethical to use unproven drugs in the current epidemic. In the United States, the Food and Drug Administration has granted expanded access to several experimental drugs for use on Ebola patients. The drugs prevent replication of Ebola virus and the vaccines work by triggering an immune response. The drugs and vaccines listed here are in clinical trials and have received support for further development, according to the Centers for Disease Control and Prevention.


A dozen patients outside West Africa have been treated with experimental drugs. Because the sample size is small and many patients have received multiple treatments, it is difficult to determine whether a particular drug has been effective.


Doses of ZMapp were sent to Monrovia, Liberia, in August to treat three doctors who contracted Ebola. One doctor died. Currently, there are no doses of ZMapp available, and even a few months from now, there may only be a few hundred doses.

Because of the peril of the situation, W.H.O. officials agreed to prioritize convalescent blood and plasma therapies for treatment. Convalescent therapy, which injects blood from recovered patients into sick patients, has had promising results. But there are major questions about its safety and efficacy in countries with inefficient health systems and a shortage of medical staff. Several international and national agencies have announced plans to develop or distribute experimental treatments for Ebola, but no time frames have been announced.

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Biomedical Sensors That Dissolve in Your Body and Reduce Infection and Waste

Biomedical Sensors That Dissolve in Your Body and Reduce Infection and Waste | Amazing Science | Scoop.it

John Rogers, a professor of engineering at the University of Illinois at Urbana-Champaign, was the lead author on a recent study published in the journal Advanced Materials. This study tested biodegradable printed circuit boards, a very efficient type of sensor with a large surface area. In the study, Rogers and his team showed they had effectively created a sensor that both does its job and is fully dissolvable.


Rogers spearheads a lab that has been at the forefront of this technology since 2008. When they were first getting started in the field of biodegradable sensors, the researchers spent several years coming up with the materials and processes that worked, Rogers said in an email. “Our research now is focusing on systems and applications, in areas ranging from biomedicine to consumer electronics,” he added.


The semiconductor, the part of the device that does the sensing, is made of two materials. One is extremely thin silicon, which the researchers shave down to the nano scale. They combine the silicon with metals that are familiar components of food and vitamins, like magnesium, zinc, and iron. The sensor is encapsulated by and rests on a set of polymers that, Rogers said, “are already used, for other purposes, in the body.”


Rogers and his team are still perfecting the sensors, but they anticipate that they could even work wirelessly by transmitting information via radio waves back to doctors’ devices. Typically, the silicon dissolves in the body in a few weeks, Rogers said, but different substances could extend the device’s lifespan.


Devices like these have the potential to change medicine for the better. Currently, the infection rate for surgeries—including the procedure needed to implant a biomedical device—is 1 to 3 percent. Usually this happens because the wound gets contaminated.


The logic for Rogers’ devices is simple: when doctors have to cut a person open less often, there’s less chance of infection. And the devices could be used as more than sensors; they could administer programmed drug delivery for conditions that require daily injections, or reduce pain by stimulating stressed nerve endings.


There are also environmental implications. In an effort to decrease the chance of infection, the health industry has relied for years on disposable, one-use devices, from syringes to hospital gowns. The result is that medical facilities generate billions of tons of trash per year, although no one is sure exactly how much. And although much of this trash could be recycled with the proper treatment, almost all of it just ends up in landfills, where it biodegrades very slowly and could present potential health hazards if people are exposed to it. Dissolvable, biodegradable devices would mean less waste in a landfill, and if a device did end up there, it would decompose rapidly.


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Killer whales can engage in cross-species vocal learning and can learn to communicate like dolphins

Killer whales can engage in cross-species vocal learning and can learn to communicate like dolphins | Amazing Science | Scoop.it

Vocal learning has also been observed in bats, some birds, and cetaceans, a group that includes whales and dolphins. But while avian researchers have characterized vocal learning in songbirds down to specific neural pathways, studying the trait in large marine animals has presented more of a challenge.


Now, University of San Diego graduate student Whitney Musser and Hubbs-SeaWorld Research Institute senior research scientist Dr. Ann Bowles have found that killer whales (Orcinus orca) can engage in cross-species vocal learning: when socialized with bottlenose dolphins, they shifted the types of sounds they made to more closely match their social partners. The results, published in The Journal of the Acoustical Society of America, suggest that vocal imitation may facilitate social interactions in cetaceans.


Killer whales have complex vocal repertoires made up of clicks, whistles and pulsed calls -- repeated brief bursts of sound punctuated with silence. The acoustic features of these vocalizations, such as their duration, pitch and pulse pattern, vary across social groups. Whales that are closely related or live together produce similar pulsed calls that carry vocal characteristics distinct to the group, known as a dialect.


"There's been an idea for a long time that killer whales learn their dialect, but it isn't enough to say they all have different dialects so therefore they learn. There needs to be some experimental proof so you can say how well they learn and what context promotes learning," said Bowles.


Testing vocal learning ability in social mammals usually requires observing the animal in a novel social situation, one that might stimulate them to communicate in new ways. Bottlenose dolphins provide a useful comparison species in this respect: they make generally similar sounds but produce them in different proportions, relying more on clicks and whistles than the pulsed calls that dominate killer whale communication.


"We had a perfect opportunity because historically, some killer whales have been held with bottlenose dolphins," said Bowles. By comparing old recordings of vocalization patterns from the cross-socialized subjects with recordings of killer whales and bottlenose dolphins housed in same-species groups, Bowles and her team were able to evaluate the degree to which killer whales learned vocalization patterns from their cross-species social partners.


All three killer whales that had been housed with dolphins for several years shifted the proportions of different call types in their repertoire to more closely match the distribution found in dolphins -- they produced more clicks and whistles and fewer pulsed calls. The researchers also found evidence that killer whales can learn completely new sounds: one killer whale that was living with dolphins at the time of the experiment learned to produce a chirp sequence that human caretakers had taught to her dolphin pool-mates before she was introduced to them.


Vocal learning skills alone don't necessarily mean that killer whales have language in the same way that humans do. However, they do indicate a high level of neural plasticity, the ability to change circuits in the brain to incorporate new information. "Killer whales seem to be really motivated to match the features of their social partners," said Bowles, though the adaptive significance of the behavior is not yet known.

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Paper-based synthetic gene networks could enable rapid detection of Ebola and other viruses

Paper-based synthetic gene networks could enable rapid detection of Ebola and other viruses | Amazing Science | Scoop.it

Synthetic gene networks hold great potential for broad biotechnology and medical applications, but so far they have been limited to the lab. A study published by Cell Press October 23rd in the journal Cell reveals a new method for using engineered gene circuits beyond the lab, allowing researchers to safely activate the cell-free, paper-based system by simply adding water. The low-cost, easy-to-use platform could enable the rapid detection of different strains of deadly viruses such as Ebola.


"Our paper-based system could not only make tools currently only available in laboratory readily fieldable, but also improve the development of new tools and the accessibility of these molecular tools to educational programs for the next generation of practitioners," says senior study author James Collins of the Wyss Institute for Biological Inspired Engineering at Harvard University.


The field of synthetic biology aims to re-engineer the molecular components of the cell to harness the power of biology. To accomplish this goal, researchers have designed synthetic gene networks that can control the activity of genes and recognize nucleic acids and small molecules. However, this technology has been restricted to the lab, in part because of biosafety concerns associated with cell-based systems and because the reactions involved have not been practical for field use.


Collins and his team overcame these hurdles by developing a cell-free, paper-based system suitable for use outside the lab. To test the clinical relevance of their method, the researchers developed sensors capable of detecting RNA molecules made from genes that allow bacteria to survive antibiotics, as well as RNA molecules encoding proteins from two different strains of the highly deadly Ebola virus. When freeze-dried onto paper, the sensors quickly detected the presence of these RNA molecules, demonstrating the usefulness of the approach for diagnostic purposes.


"Considering the projected cost, reaction time, ease of use, and no requirement for laboratory infrastructure, we envision paper-based synthetic gene networks significantly expanding the role of synthetic biology in the clinic, global health, industry, research, and education," Collins says.

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Integrating laser diode and ultrasound transducer array to build compact medical imaging device

Integrating laser diode and ultrasound transducer array to build compact medical imaging device | Amazing Science | Scoop.it

Scientists at the MIRA research institute, in collaboration with various companies, have developed a prototype of a handy device that combines echoscopy (ultrasound) with photoacoustics. Combining these two medical imaging technologies in a compact device is designed, among other things, to enable the amount of inflammation in rheumatic patients' joints to be measured more simply and precisely. The researchers expect that the technology will eventually also be able to play a role in detecting the severity of burns, skin cancer and furring of the arteries. The prototype is presented in the scientific journal Optics Express.


Echoscopy and photoacoustics are complementary medical imaging technologies. Photoacoustics involves sending brief laser pulses into the patient's body. When the laser light hits a blood vessel, for example, it is locally converted into heat, which causes a minor rise in pressure. This propagates through the body like a sound wave and can then be measured on the skin. Echoscopy involves sending ultrasound waves into the body: different tissues reflect them in different ways, and they too can then be detected on the skin. Whereas echoscopy provides an image of structures, photoacoustics can provide an image containing more functional information, such as the presence of blood.

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High-speed evolution in the lab: Geneticists evaluate cost-effective pool genome analysis

High-speed evolution in the lab: Geneticists evaluate cost-effective pool genome analysis | Amazing Science | Scoop.it

Life implies change. And this holds true for genes as well. Organisms require a flexible genome in order to adapt to changes in the local environment. Christian Schlötterer and his team from the Institute for Population Genetics at the University of Veterinary Medicine, Vienna study the genomes of entire populations. The scientists want to know why individuals differ from each other and how these differences are encoded in the DNA. In two review papers published in the journals Nature Reviews Genetics and Heredity, they discuss why DNA sequencing of entire groups can be an efficient and cost-effective way to answer these questions.   

DNA analysis has become increasingly efficient and cost-effective since the human genome was first fully sequenced in the year 2001. Sequencing a complete genome, however, still costs around US$1,000. Sequencing the genetic code of hundreds of individuals would therefore be very expensive and time-consuming. In particular for non-human studies, researchers very quickly hit the limit of financial feasibility.  

The solution to this problem is pool sequencing (Pool-Seq). Schlötterer and his team sequence entire groups of fruit flies (Drosophila melanogaster) at once instead of carrying out many individual sequencing reactions. While the resulting genetic information cannot be attributed to a single individual, the complete data set still provides important genetic information about the entire population.


In order to understand how organisms react to changes in the local environment, the genomes of entire populations can be analysed using Pool-Seq, before and after changed conditions. To do so, the researchers use the method of evolve and resequence (E&R). Schlötterer received an ERC Advanced Grant for this approach in 2012. E&R is a method in which the DNA of a group of individuals is sequenced.  After exposing the descendents of this group for several generations to a certain stress, such as high temperature, extreme cold or UV radiation, and the evolved group is then sequenced again. A comparison of the two data sets uncovers genes that have changed in response to the selective stress. The approach makes it possible, for example, to filter out the genes that are involved in a darker pigmentation in response to UV radiation. 


“Using this principle, we can perform evolution experiments at high speed. We are using this method to address a broad range of questions, ranging from the identification of genes which influence aging, or genes protecting against diseases and finally to understand the genetic changes which reduce the impact of climate change,” Schlötterer explains.

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Siberian thighbone data adjust time of human and Neanderthal interbreeding to around 50,000 years ago

Siberian thighbone data adjust time of human and Neanderthal interbreeding to around 50,000 years ago | Amazing Science | Scoop.it

New research on a 45,000-year-old Siberian thighbone has narrowed the window of time when humans and Neanderthals interbred to between 50,000 and 60,000 years ago, and has shown that modern humans reached northern Eurasia substantially earlier than some scientists thought.


Qiaomei Fu, a postdoctoral fellow at Harvard Medical School (HMS) and first author of a paper describing the research, said the sample had a long history before making its way into her hands.


The bone was found eroding out of a Siberian riverbank, but no one knows precisely where. The bone changed hands several times before finding its way to the Max Planck Institute for Evolutionary Anthropology in Germany, where Fu was working with professors Janet Kelso and Svante Pääbo. Fu put the finishing touches on the research after she started in the laboratory of David Reich, HMS genetics professor.


Carbon dating and molecular analysis filled in many of the blanks about the sample. Testing determined that the sample was from an individual who lived 45,000 years ago on a diet that included plants or plant eaters and fish or other aquatic life.


Reich and Fu said the sample was remarkable because of the extraordinary preservation of its DNA, which allowed Fu, using the latest techniques for ancient DNA analysis, to extract a high-quality genome sequence. The sequence, Reich said, is significantly higher in quality than most genome sequences of present-day people generated for analysis of disease risk.


The sequence revealed that the bone came from a modern human, a man whose remains are the oldest ever found and carbon-dated outside of Africa and the Middle East. Comparison to diverse humans around the world today showed that the man was a member of one of the most ancient non-African populations.


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Extremely high-resolution MRI: New MRI method detects single hydrogen atom

Extremely high-resolution MRI: New MRI method detects single hydrogen atom | Amazing Science | Scoop.it

For the first time, researchers have succeeded to detect a single hydrogen atom using magnetic resonance imaging, which signifies a huge increase in the technology's spatial resolution. In the future, single-atom MRI could be used to shed new light on protein structures.


Conventional magnetic resonance imaging (MRI), well-known from its use in hospitals, can typically resolve details of up to one tenth of a millimeter, for example in cross-sectional images of the human body. Together with colleagues at the University of Leipzig, researchers of ETH Zurich are working on massively increasing the resolution of the technique, with the goal of eventually imaging at the level of single molecules – demanding an over one million times finer resolution. By detecting the signal from a single hydrogen atom, they have now reached an important milestone toward such single-atom MRI.


The research team led by Christian Degen, Professor at the Laboratory for Solid State Physics, developed a different and vastly more sensitive measurement technique for MRI signals. In standard hospital instruments, the magnetisation of the atomic nuclei in the human body is inductively measured using an electromagnetic coil. "MRI is nowadays a mature technology and its spatial resolution has remained largely the same over the last ten years. Physical constraints preclude increasing the resolution much further," explains Degen. In their experiments, the ETH researchers measured the MRI signal with a novel diamond sensor chip using an optical readout in a fluorescence microscope.


The sensor consisted of an impurity in diamond known as the nitrogen-vacancy centre. In this case, two carbon atoms are missing in the otherwise regular diamond lattice, while one of them is replaced by a nitrogen atom. The nitrogen-vacancy centre is both fluorescent and magnetic, making it suitable for extremely precise magnetic field measurements.


For their experiment, the researchers prepared an approximately 2x2 millimeter piece of diamond such that nitrogen-vacancy centers formed only a few nanometers below the surface. By an optical measurement of the magnetisation, they were in several cases able to confirm the presence of other magnetic atomic nuclei in the immediate vicinity. "Quantum mechanics then provides an elegant proof of whether one has detected an individual nucleus, or rather a cluster of several hydrogen atoms," states Degen. The researchers also used the measured data to localize the hydrogen nuclei with respect to the nitrogen-vacancy centre with an accuracy of better than one angstrom


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What does the next generation telescope need to detect life?

What does the next generation telescope need to detect life? | Amazing Science | Scoop.it

Almost 2,000 extrasolar planets have been discovered to date and this number is constantly increasing. Yet, we still know little about these alien worlds, especially their atmospheres. The atmospheres of terrestrial exoplanets could betray the presence of life on the planet, sparking NASA's interest in acquiring the spectra that appears as starlight shines through these planetary atmospheres.

A paper by Timothy Brandt and David Spiegel, exo-planetary scientists at the Institute for Advanced Study, Princeton, details what is needed in a next generation telescope for it to be capable of detecting signatures of life in the atmospheres of alien planets. The paper has been published in the September issue of the journal Proceedings of the National Academy of Sciences.

Astronomers employ several different methods to study the atmospheres of gas giants that orbit close to their host stars. One such method involves comparing the spectrum of a star when a planet is transiting across the surface to a spectrum when the planet is out of transit. By comparing the spectra, it is possible to see which elements exist in the planet's atmosphere.


Methods like this still can't be used for terrestrial planets, as the height of the atmosphere engulfing a rocky planet is miniscule compared to that of a gas giant. Earth-like planets also orbit their stars at a larger distance, making it even more difficult to observe their atmospheres.


Observations of terrestrial planet atmospheres will require a specialized space mission that will use a coronograph to block out the blinding light of the star. While the James Webb Space Telescope, due to launch in 2018, will be capable of detecting elements in planetary atmospheres, it will still be limited to more massive planets.


"Our paper is an attempt to better define the requirements for a mission capable of detecting oxygen and water," says Brandt. "This is NASA's target, assuming technology developments in coronagraphy and adaptive optics permit it."

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New 'smart' material improves removal of arsenic from drinking water

New 'smart' material improves removal of arsenic from drinking water | Amazing Science | Scoop.it

Scientists have created a new material that can remove double the amount of arsenic from water than the leading material for water treatment. Arsenic is a toxic element found naturally in groundwater. Long-term exposure over a number of years to elevated concentrations of arsenate, the chemical form of arsenic in water, is associated with debilitating, and potentially fatal, illnesses including cancer, heart and lung disease, gastrointestinal problems and neurological disorders.


Arsenic-contaminated drinking water has been identified in many countries across the globe, including Bangladesh, Chile, Mexico, Argentina, Australia, USA and parts of the UK. Recent estimates suggest that more than 200 million people are unknowingly exposed to unsafe levels of arsenic in their drinking water.  


In a new study published inChemistry - A European Journal, scientists at Imperial College London have designed, tested and patented a new zinc-based material that can selectively bind to arsenate with strong affinity. The scientists hope this material could ultimately be used to improve quality of domestic water filters and reduce the amount of arsenic that people are exposed to, in areas with known or suspected high arsenic content.


In 2006 the World Health Organization issued guidelines defining safe concentration levels of arsenic as 10 parts per billion but several countries affected by arsenic-contaminated groundwater have legal concentration limits above this guideline and recent evidence suggests that long-term exposure to smaller concentrations can be harmful.


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Brain barrier opened for first time to treat cancer

Brain barrier opened for first time to treat cancer | Amazing Science | Scoop.it

For the first time, doctors have opened and closed the brain's protector – the blood-brain barrier – on demand. The breakthrough will allow drugs to reach diseased areas of the brain that are otherwise out of bounds. Ultimately, it could make it easier to treat conditions such as Alzheimer's and brain cancer.


The blood-brain barrier (BBB) is a sheath of cells that wraps around blood vessels (in black) throughout the brain. It protects precious brain tissue from toxins in the bloodstream, but it is a major obstacle for treating brain disorders because it also blocks the passage of drugs.


Several teams have opened the barrier in animals to sneak drugs through. Now Michael Canney at Paris-based medical start-up CarThera, and his colleagues have managed it in people using an ultrasound brain implant and an injection of microbubbles.

When ultrasound waves meet microbubbles in the blood, they make the bubbles vibrate. This pushes apart the cells of the BBB.


With surgeon Alexandre Carpentier at Pitié-Salpêtrière Hospital in Paris, Canney tested the approach in people with a recurrence of glioblastoma, the most aggressive type of brain tumour. People with this cancer have surgery to remove the tumours and then chemotherapy drugs, such as Carboplatin, are used to try to kill any remaining tumour cells. Tumours make the BBB leaky, allowing in a tiny amount of chemo drugs: if more could get through, their impact would be greater, says Canney.


The team tested the idea on four patients by implanting an ultrasound transducer through a hole already made in their skulls during tumour-removal surgery. They were then given an injection of microbubbles and had the transducer switched on for 2 minutes. This sent low-intensity pulses of ultrasound into a region of the brain just 10 millimetres by 4 mm. Canney reckons this makes the BBB in this region more permeable for about 6 hours. In this time window, each person received normal chemotherapy.

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Warwick Raverty's curator insight, October 22, 2014 7:48 PM

Hope at last for people with inoperable brain tumours!

Nicole Masureik's curator insight, October 23, 2014 2:41 AM

What an amazing advance! This could open doors for all sorts of things. However, there is so much about the functioning of the brain that we don't understand, that we will need to watch the long term effects carefully.

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Human skin cells reprogrammed directly into brain cells with combination of microRNAs and transcription factors

Human skin cells reprogrammed directly into brain cells with combination of microRNAs and transcription factors | Amazing Science | Scoop.it

Scientists have described a way to convert human skin cells directly into a specific type of brain cell affected by Huntington’s disease, an ultimately fatal neurodegenerative disorder. Unlike other techniques that turn one cell type into another, this new process does not pass through a stem cell phase, avoiding the production of multiple cell types, the study’s authors report.


The researchers, at Washington University School of Medicine in St. Louis, demonstrated that these converted cells survived at least six months after injection into the brains of mice and behaved similarly to native cells in the brain.


“Not only did these transplanted cells survive in the mouse brain, they showed functional properties similar to those of native cells,” said senior author Andrew S. Yoo, PhD, assistant professor of developmental biology. “These cells are known to extend projections into certain brain regions. And we found the human transplanted cells also connected to these distant targets in the mouse brain. That’s a landmark point about this paper.”


The work appears Oct. 22 in the journal Neuron.


The investigators produced a specific type of brain cell called medium spiny neurons, which are important for controlling movement. They are the primary cells affected in Huntington’s disease, an inherited genetic disorder that causes involuntary muscle movements and cognitive decline usually beginning in middle-adulthood. Patients with the condition live about 20 years following the onset of symptoms, which steadily worsen over time. 

The research involved adult human skin cells, rather than more commonly studied mouse cells or even human cells at an earlier stage of development. In regard to potential future therapies, the ability to convert adult human cells presents the possibility of using a patient’s own skin cells, which are easily accessible and won’t be rejected by the immune system.


To reprogram these cells, Yoo and his colleagues put the skin cells in an environment that closely mimics the environment of brain cells. They knew from past work that exposure to two small molecules of RNA, a close chemical cousin of DNA, could turn skin cells into a mix of different types of neurons.


In a skin cell, the DNA instructions for how to be a brain cell, or any other type of cell, is neatly packed away, unused. In past research published in Nature, Yoo and his colleagues showed that exposure to two microRNAs called miR-9 and miR-124 altered the machinery that governs packaging of DNA. Though the investigators still are unraveling the details of this complex process, these microRNAs appear to be opening up the tightly packaged sections of DNA important for brain cells, allowing expression of genes governing development and function of neurons.

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Weeks after winning a Nobel Prize for his microscope, Eric Betzig just revolutionized microscopy again

Weeks after winning a Nobel Prize for his microscope, Eric Betzig just revolutionized microscopy again | Amazing Science | Scoop.it
The new technique allows high-speed, high-resolution shots of cells in action.


Earlier this month Eric Betzig shared the Nobel Prize in chemistry for his work on high-resolution microscopes -- specifically the one he'd designed and built on a friend's living room floorBut when Betzig, a researcher at the Howard Hughes Medical Institute's Janelia Research Campus in Ashburn, Virginia, got news of his win, his best work yet was still a few weeks away from being published.Thursday in Science, he and a team of his colleagues reported on a new microscopy technique that allows them to observe living cellular processes at groundbreaking resolution and speed. Betzig came up with his Nobel-winning microscope (PALM) when he'd grown frustrated with the limitations of other microscope technologies. The so-called lattice light-sheet microscopy that he describes in Thursday's paper was the result of his eventual boredom with PALM.


"Again, I just started to understand the limits of the technology," Betzig said. PALM was great at looking at living systems, but only when they moved slowly. It couldn't take  measurements quickly enough to get high-resolution pictures of fast cellular divisions.


Trying to understand biology using these microscopes is like piecing together a football game from high-resolution photos, Betzig said: You can see images of a pass, and a touchdown, and of the cheerleaders doing a pyramid. But the rules of the game would only become clear once you saw a game on video.


"I'd been looking at those pictures my whole life," Betzig said. "It was time to take a look at the living stuff in action." Until now, the best microscope for viewing living systems as they moved were confocal microscopes. They beam light down onto a sample of cells. The light penetrates the whole sample and bounces back.


But even though a scientist can only focus his lens on one small section of the sample, light is being blasted onto the cells from above and below. This causes two problems: It creates a sort of haze around the area being focused on, and it's also damaging to the cell sample. The light is toxic, and degrades the living system over time. Betzig's new microscope solves this by generating a sheet of light that comes in from the side of the sample, made up of a series of beams that harm the sample less than one solid cone of light. Scientists can now snap a high-res image of the entire section they're illuminating, without exposing the rest of the sample to any light at all.

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Alan Eustace, Google, Jumps From Top of Stratosphere, Falling Faster Than The Speed of Sound

Alan Eustace, Google, Jumps From Top of Stratosphere, Falling Faster Than The Speed of Sound | Amazing Science | Scoop.it

A well-known computer scientist parachuted from a balloon near the top of the stratosphere on Friday, falling faster than the speed of sound and breaking the world altitude record set just two years ago.


The jump was made by Alan Eustace, 57, a senior vice president at Google. At dawn he was lifted by a balloon filled with 35,000 cubic feet of helium, from an abandoned runway at the airport here.


For a little over two hours, the balloon ascended at speeds up to 1,600 feet per minute to an altitude of 135,908 feet, more than 25 miles. Mr. Eustace dangled underneath in a specially designed spacesuit with an elaborate life-support system. He returned to earth just 15 minutes after starting his fall.


“It was amazing,” he said. “It was beautiful. You could see the darkness of space and you could see the layers of atmosphere, which I had never seen before.”


Mr. Eustace cut himself loose from the balloon with the aid of a small explosive device and plummeted toward the earth at a speeds that peaked at more than 800 miles per hour, setting off a small sonic boom heard by observers on the ground.

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Marc Kneepkens's curator insight, October 24, 2014 2:39 PM

Some people dare to take a challenge. They prepare well, they calculate the risk and then they just do it. Awesome.

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Acoustic Metamaterial Superenhances Current Weak Sound Detection Limits By More Than 10 Fold

Acoustic Metamaterial Superenhances Current Weak Sound Detection Limits By More Than 10 Fold | Amazing Science | Scoop.it

Metamaterials are composite materials with exacting, repetitive subwavelength structural patterns that have properties not found in nature.  Thus far, they have been used to create novel optical materials with negative index of refraction, thus permitting “superlenses” that have enhanced optical resolution beyond conventional lenses, and “invisibility cloaks” that bend at least a narrow band of radiation around a cloaked object.


A group of researchers from the University of Maryland (UMD) have created, using a combination of theory, computation, and experimentation, a new acoustic metamaterial that dramatically amplifies acoustic signals, more than 10 times past the detection limit of conventional sensors.


The key property of the novel metamaterial is its “graded refractive index” or GRIN for short.  The ideal GRIN material has an increasing index of refraction along one axis, but constant along the other two axes. This is realized physically by a tapered slab made up of a regular stacked array of stainless steel plates, each one separated by a gap of air 1.4 mm wide.  The distance between plates is 3.4 mm. The height and thickness of the stainless steel plates are given by 40 mm and 2 mm respectively. The width of each increases from 0.5 to 50 mm with an increment of 0.5 mm.  Other ways of instantiating a GRIN material are possible.


Sounds waves projected along the axis perpendicular to the plates experience a compressive effect, causing an increase in the frequency of the sound and concentrating the energy into a smaller volume space mostly along the direction of travel.  The compression intensifies or amplifies the sound pressure wave, before reaching a sensor or detector at the end.  The sensor then detects the strongly amplified sound wave, which prior to its travel into the device may have been near or below the detection threshold with a signal-to-noise (SNR) ratio of less than or equal to 1.


The material has a number of other advantages.  In the electromagnetic domain it is immune to interference, possesses low intrinsic noise, and is highly sensitive.  In the acoustic domain it is amplifying in pressure waves and able to accept different frequencies in multiplex.  In an experiment the experimenters showed that a very weak signal, at only 27% the strength of ambient noise (SNR of 0.27), can be amplified substantially over 100-fold, bringing the SNR up to 32.7.  The metamaterial by virtue of its waveguide and pressure amplification overcomes the detection limit of conventional acoustic sensors.

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Gene therapy restores sense of smell in mice

Gene therapy restores sense of smell in mice | Amazing Science | Scoop.it

A groups of researchers, lead by the University of Michigan, looked at mice with a mutation in their Ift88 gene, which meant they struggled to produce cilia and could not smell. The group created a virus which was capable of infecting cells with a working version of the Ift88 gene. This was injected into the nose on three consecutive days. This was able to restore the cilia and a sense of smell.


Prof Philip Beales from University College London was involved in the study. He told the BBC: "It is a proof of concept that has shown we can get that gene back into these cells, produce the right protein, produce cilia and function as expected. He said the mice were then able to use their sense of smell to seek out food. However, it is hoped a similar approach could be used for other symptoms of the disorders.


Dr James Battey, director of the US National Institute on Deafness and Other Communications Disorders which part funded the research said: "These results could lead to one of the first therapeutic options for treating people with congenital anosmia. "They also set the stage for therapeutic approaches to treating diseases that involve cilia dysfunction in other organ systems, many of which can be fatal if left untreated."


The study is published in Nature Medicine.

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Lucky star escapes black hole with minor damage

Lucky star escapes black hole with minor damage | Amazing Science | Scoop.it
Astronomers have gotten the closest look yet at what happens when a black hole takes a bite out of a star—and the star lives to tell the tale.


We may think of black holes as swallowing entire stars—or any other object that wanders too close to their immense gravity. But sometimes, a star that is almost captured by a black hole escapes with only a portion of its mass torn off. Such was the case for a star some 650 million light years away toward Ursa Major, the constellation that contains the "Big Dipper," where a supermassive black hole tore off a chunk of material from a star that got away.


Astronomers at The Ohio State University couldn't see the star itself with their All-Sky Automated Survey for Supernovae (ASAS-SN, pronounced "assassin"). But they did see the light that flared as the black hole "ate" the material that it managed to capture.


In a paper to appear in the Monthly Notices of the Royal Astronomical Society, they report that the star and the black hole are located in a galaxy outside of the newly dubbed Laniakea Supercluster, of which our home Milky Way Galaxy is a part.


If Laniakea is our galactic "city," this event—called a "tidal disruption event," or TDE— happened in our larger metropolitan area. Still, it's the closest TDE ever spotted, and it gives astronomers the best chance yet of learning more about how supermassive black holes form and grow.


ASAS-SN has so far spotted more than 60 bright and nearby supernovae; one of the program's other goals is to try to determine how often TDEs happen in the nearby universe. But study co-author Krzysztof Stanek, professor of astronomy at Ohio State, and his collaborators were surprised to find one in January 2014, just a few months after ASAS-SN's four telescopes in Hawaii began gathering data.

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Terrestrial Return Vehicle to provide parcel post for the ISS

Terrestrial Return Vehicle to provide parcel post for the ISS | Amazing Science | Scoop.it

So much attention is paid to how to get into space that we often forget that getting back can be just as difficult. For example, getting experiment samples back from the International Space Station (ISS) is a logistical nightmare. Intuitive Machines' Terrestrial Return Vehicle (TRV) system may change that by making sending small payloads back to Earth as easy as mailing a parcel.


Getting samples back from the ISS currently means hitching a ride on a returning cargo or crew ferry craft, but this happens only a few times a year with every ounce already spoken for. That may be okay for most items, but what about the ones that can't wait?


The Terrestrial Return Vehicle (TRV) is a commercial service being developed by Intuitive Machines and NASA as part of a project under the Center for the Advancement of Science in Space (CASIS), which is responsible for installing the TRV on the space station and non-flight systems. It's designed to return small samples on demand from the ISS on the same day, and is suitable for critical and perishable materials that can't wait for the next ship home.


The TRV system is designed to be stored in the habitable volume of the ISS until required. When loaded up with its cargo, the TRV is placed in the Japanese Experiment Module (JEM) airlock, where the Cyclops ejection mechanism and the JEM Robotic Manipulator System are used to deploy it. Once released from the ISS, the TRV's guidance and propulsion systems take over and execute a controlled reentry maneuver before the craft's airfoil is deployed and it touches down at its designated spaceport.

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New single-cell analysis: Tiny dual-channel quartz needle for nanoelectrospray ionization mass spectrometry

New single-cell analysis: Tiny dual-channel quartz needle for nanoelectrospray ionization mass spectrometry | Amazing Science | Scoop.it

By inserting this tiny dual-bore needle into a living single cell, researchers can send its contents to a mass spectrometer for analysis.


With a new mass spectrometry technique, researchers can survey the suite of small molecules inside a single cell by inserting a tiny probe. The method requires little sample preparation that would affect a cell’s chemistry and can analyze the contents of an individual cell in about three minutes (Anal. Chem. 2014, DOI: 10.1021/ac5029038).


Just as no two people are identical, no two cells are the same, says Zhibo Yang, a chemist at the University of Oklahoma who developed the new technique with his colleagues. Understanding biochemical differences between cells can help researchers pinpoint the hallmarks of cancer or neurological disease and investigate how individual cells respond to drugs. In 2012, the National Institutes of Health allotted $90 million to support research into this area through its Single Cell Analysis Program.


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Unusual Distribution of Organics Found in Titan’s Atmosphere

Unusual Distribution of Organics Found in Titan’s Atmosphere | Amazing Science | Scoop.it

A new mystery of Titan has been uncovered by astronomers using their latest asset in the high altitude desert of Chile. Using the now fully deployed Atacama Large Millimeter Array (ALMA) telescope in Chile, astronomers moved from observing comets to Titan. A single 3 minute observation revealed organic molecules that are askew in the atmosphere of Titan. The molecules in question should be smoothly distributed across the atmosphere but they are not.


The Cassini/Huygens spacecraft at the Saturn system has been revealing the oddities of Titan to us, with its lakes and rain clouds of methane and an atmosphere thicker than Earth’s. But the new observations by ALMA of Titan underscore how much more can be learned about Titan and also how incredible the ALMA array is.


The ALMA astronomers called it a “brief 3 minute snapshot of Titan.” They found zones of organic molecules offset from the Titan polar regions. The molecules observed were hydrogen isocyanide (HNC) and cyanoacetylene (HC3N). It is a complete surprise to the astrochemist Martin Cordiner, from NASA Goddard Space Flight Center in Greenbelt, Maryland. Cordiner is the lead author of the work published in the latest release of Astrophysical Journal Letters.


The NASA Goddard press release states, “At the highest altitudes, the gas pockets appeared to be shifted away from the poles. These off-pole locations are unexpected because the fast-moving winds in Titan’s middle atmosphere move in an east–west direction, forming zones similar to Jupiter’s bands, though much less pronounced. Within each zone, the atmospheric gases should, for the most part, be thoroughly mixed.”


When one hears there is a strange, skewed combination of organic compounds somewhere, the first thing to come to mind is life. However, the astrochemists in this study are not concluding that they found a signature of life. There are, in fact, other explanations that involve simpler forces of nature. The Sun and Saturn’s magnetic field delivers light and energized particles to Titan’s atmosphere. This energy causes the formation of complex organics in the Titan atmosphere. But how these two molecules – HNC and HC3N came to have a skewed distribution is, as the astrochemists said, “very intriguing.” Cordiner stated, “This is an unexpected and potentially groundbreaking discovery… a fascinating new problem.”

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Chamber of secrets: How cells organise themselves influences their ability to communicate

Chamber of secrets: How cells organise themselves influences their ability to communicate | Amazing Science | Scoop.it

Durdu, a PhD student in Darren Gilmour’s lab at EMBL, found this behaviour in specific groups of cells in the zebrafish: the cells that will develop into the animal’s ‘lateral line’, a series of ear-like organs along the fish’s flank that allow it to sense changes in water pressure. As a zebrafish develops, a mass of cells moves along the developing animal’s side. At the point where one of these organs should form, a group of cells at the rear assembles into a huddle and stops, eventually developing into the organ. The rest of the cells, meanwhile, have moved on, until another group stops to form another organ, and so on. The cells that group together and stop to form the future organ also change shape, going from flat, crawling cells to upright, tear-shaped cells that come together like cloves in a bulb of garlic. Durdu found that these ‘garlic cloves’ huddle around a shared space, or lumen, in which they trap a molecule cells use to communicate: FGF. 


“Normally, FGF acts as a long-range communication signal. In the lateral line, we find that most of this signal is normally just wafting over the cells’ heads,” says Gilmour. “But when cells get together and huddle they can trap and concentrate this signal in their shared lumen, and make a decision that the others can’t: they stop moving.”


The EMBL scientists found that, by enabling a group of cells to increase the concentration of FGF they are in contact with, the shared lumen plays a critical role in determining when and where the huddles stop moving. When the scientists increased the concentration of FGF, cell huddles came to a standstill more abruptly, forming organs that were closer together. And when they decreased the level of FGF, huddles continued to migrate for longer and formed organs that were further apart.


“All epithelial cells – and that’s the cells that make up most of the organs in our bodies – can do this, so you could imagine that this type of local chamber could be forming transiently in many different parts of the body, whenever cells need to self-organise and communicate,” Gilmour says.


When the scientists broke up cell huddles in their zebrafish embryos, FGF leaked out. When this happens the cells in a group are no longer able to communicate efficiently, leading the scientists to wonder if this influence of organisation on communication could play a role in wound repair. When our skin is scratched, cells that were standing upright ‘lie down’ and start crawling – in essence, local huddles break up and cells change their behaviour. Another situation where cells may be huddling to communicate within a group, Gilmour and Durdu posit, is in organoids – self-assembled organ-like structures grown in the lab, which start by forming a common lumen.


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Tiny Creatures Come to Life in Nikon's 'Small Worlds' Photo Contest

Tiny Creatures Come to Life in Nikon's 'Small Worlds' Photo Contest | Amazing Science | Scoop.it

Without access to a microscope or a sophisticated zoom lens, most people don't get to see plant pores and cricket tongues up close. But the entrants in the 2014 Nikon Small World photography contest offer an intimate look at tiny realms rarely seen outside of a lab. The judges of the annual contest will reveal their top picks on Oct. 30, but the following images are a sample of the submissions. More information can be found on the contest website.

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Noncovalent, Self-Assembled, Robust, Porous Material That Adsorbs Greenhouse Gas

Noncovalent, Self-Assembled, Robust, Porous Material That Adsorbs Greenhouse Gas | Amazing Science | Scoop.it

Researchers from the Department of Chemistry at the University of Houston have created noncovalent organic frameworks, a new type of porous material that overcomes some barriers in the development of porous material technologies.  The new wonder material is highly processable, self-assembled, possessing of a superstructure with large, 16 angstrom pores (Figure above).  The material has a high affinity for hydrocarbons suggesting applications for use as an energy storage substrate.  In addition, the material also captures CFCs and fluorocarbons, both potent greenhouse gas species.  The capture capacity is up to 75% of the original weight.


The field of porous materials has experienced two other, prior twin advances in the area of metal-organic and covalent organic frameworks though they are plagued by the problem of low processability as the extended crystalline structure makes them impossible to dissolve without decomposition.


Remarkably, the building block of the noncovalent porous material is a single molecule trispyrazole, which stack and self-assemble into a large, porous, crystal-like configuration.  The author characterizes the pores as “infinite one-dimensional channels protruding throughout the crystal along the crystallographic c axis”.  The interior “lining” of the channels is arrayed with fluorines.


The entire super structure is stabilized by noncovalent hydrogen bonds and “pi-pi” stacking – hallmarks of a “supramolecular” material.  H-bonds and pi-interactions  are considered “weak” associations between molecules, but by virtue of the sheer number and surface area of interactions, the material turns out to be thermally very stable (up to 250 degrees C) and resistant to solvents, acids and bases.  Engineers interested in manipulating the material would find most interesting that its solubility in DMSO can be tuned by temperature.


Of great interest in porous materials is measurement of the “effective surface area” in the pores, for a given weight of the porous material.  A common measure of the surface area is the Brunauer–Emmett–Teller surface area.  Using nitrogen adsorption measurements the surface area was determined to be 1,159 m2 g−1.  For comparison activated charcoal used in water filters has a surface area of about 500 m2 g−1.  The high surface area is the reason for the high capture weight proportion (75%).

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