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Most abundant ocean viruses attack bacteria that are important for the carbon cycle

Most abundant ocean viruses attack bacteria that are important for the carbon cycle | Amazing Science | Scoop.it

In one corner is the Earth’s most abundant organism: SAR11, an ocean-living bacterium that survives where most other cells would die and plays a major role in the planet’s carbon cycle. It had been theorized that SAR11 was so small and widespread that it must be invulnerable to attack.

 

In the other corner, and so strange looking that scientists previously didn’t even recognize what they were, are “Pelagiphages,” viruses now known to infect SAR11 and routinely kill millions of these cells every second.

 

How this fight turns out is of more than casual interest, because SAR11 has a huge effect on the amount of carbon dioxide that enters the atmosphere, and the overall biology of the oceans.

 

“There’s a war going on in our oceans, a huge war, and we never even saw it,” says Stephen Giovannoni, a professor of microbiology at Oregon State University. “This is an important piece of the puzzle in how carbon is stored or released in the sea.” The analysis shows that the new viruses—like their hosts—are the most abundant on record.

 

The paper in Nature describes four previously unknown viruses that infect SAR11. To prove the viruses were as abundant as their hosts, Giovannoni and colleagues teamed up with researchers at the University of Arizona’s Tucson Marine Phage Research Lab, led by Matthew Sullivan, who had developed accurate methods for measuring viral diversity in nature.

 

The analysis shows that the new viruses—like their hosts—are the most abundant on record. Giovannoni’s group discovered the Pelagiphage viral families by using “old-fashioned” research methods, growing the cells and viruses in a laboratory, instead of the tools of modern genomics, and found the new type of virus.

 

“Because they are so new, these viruses were virtually unrecognizable to us based on their DNA,” Giovannoni says. “The viruses themselves, of course, appear to be just as abundant as SAR11.”

 

Sullivan explains the method for discovering viruses in the oceans based on their genomes his group developed over four years is at least 1,000 times more accurate than previous methods.

 

Their work resulted in the Pacific Ocean Virus dataset. This dataset, Sullivan explains, is the viral equivalent of the Global Ocean Sampling Expedition by former human genome researcher J. Craig Venter, who sailed across the world’s oceans sampling, sequencing, and analyzing the DNA of the microorganisms living in these waters. The new findings on SAR11 disprove the theory that the bacteria are immune to viral predation, Giovannoni and his co-authors say.

 

“In general, every living cell is vulnerable to viral infection,” says Giovannoni, who first discovered SAR11 in 1990. “What has been so puzzling about SAR11 was its sheer abundance, there was simply so much of it that some scientists believed it must not get attacked by viruses.” What the new research shows, Giovannoni says, is that SAR11 is competitive, good at scavenging organic carbon, and effective at changing quickly to avoid infection. Because of this, it thrives and persists in abundance even though the new viruses are constantly killing it.

 

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This drone can automatically follow forest trails to track down lost hikers

This drone can automatically follow forest trails to track down lost hikers | Amazing Science | Scoop.it
A team of researchers at the University of Zurich just announced that they've developed a drone software that's capable of identifying and following trails.


Leave the breadcrumbs at home, folks, because just this week, a group of researchers in Switzerland announced the development of a drone capable of recognizing and following man-made forest trails. A collaborative effort between the University of Zurich and the Dalle Molle Institute of Artificial Intelligence, the conducted research was reportedly done to remedy the increasing number of lost hikers each year.


According to the University of Zurich, an estimated 1,000 emergency calls are made each year in regards to injured or lost hikers in Switzerland alone, an issue the group believes “inexpensive” drones could solve quickly.


Though the drone itself may get the bulk of the spotlight, it’s the artificial intelligence software developed by the partnership that deserves much of the credit. Run via a combination of AI algorithms, the software continuously scans its surroundings by way of two smartphone-like cameras built-in to the drone’s exterior. As the craft autonomously navigates a forested area, it consistently detects trails before piloting itself down open paths. However, the term “AI algorithms” is an incredibly easy way of describing something wildly complex. Before diving into the research, the team knew it would have to develop a supremely talented computing brain.

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Turning the Volume of Gene Expression Up and Down

Turning the Volume of Gene Expression Up and Down | Amazing Science | Scoop.it

Gene expression can be turned on and off like a switch, or it can be finely adjusted, as with a volume control knob. Dr Garth Ilsley, research scientist in Prof. Nicholas Luscombe’s unit at the Okinawa Institute of Science and Technology Graduate University (OIST), has developed a mathematical model that shows how to predictably tune gene expression. This was validated experimentally using a technique for adjusting gene expression in fruit fly embryos pioneered by Dr Justin Crocker in the group of Dr David Stern at Janelia Research Campus in the U.S. This study, published in Nature Genetics, has important implications in cellular and developmental biology, with potential applications in stem cell reprogramming and regenerative medicine.


Transcription factors are proteins that bind to special regions of DNA called enhancers, so as to regulate gene expression. Some transcription factors activate gene expression, while others repress it. Gene expression level is like the volume of a radio; some transcription factors turn the volume up, while others turn it down. Scientists have investigated how activation and repression work and how to predict the level of gene expression. In the same way, by turning the volume knob of a radio, it is possible to know how loud or soft the music will be and to regulate it—except that, in this case, each transcription factor has its own volume knob all acting on the same speaker. The challenge is to understand how they all work together to produce the right volume.


Dr Ilsley applied a new mathematical model that does not require information about the number and position of transcription factors binding to the enhancer, which would be like knowing the inner workings of the radio. Instead, the model correctly predicts the final volume only by knowing how the volume knobs are turned. These predictions were tested experimentally using artificial transcription factors that activate and repress gene expression with different strengths.


Scientists worked with fruit fly (Drosophila melanogaster) early stage embryos. The mathematical model shows that expression of genes that determine segmentation of the fruit fly body from head to tail is tunable. Experimental results match the model’s prediction, showing that artificial activators and repressors can increase and decrease gene expression gradually in a way that is controllable and reproducible. This is like attaching yet another volume knob to the radio and finding that it works in concert with the existing knobs. Beyond gene expression level, the model was also able to predict in which location in the embryo, for example ventral or dorsal, the gene would be expressed. “It was our dream to bring model and experiment together,” enthuses Dr Ilsley.


This study also shows that enhancers can acquire new activators and repressors quite flexibly. “You can bring in foreign transcription factors and the enhancers still work. The enhancers we looked at are not brittle at all. This is evolutionarily important, because it shows how enhancer activity can be adjusted gradually and remain working in changing contexts,” points out Dr Ilsley. “Each activator and repressor is like a generic component that takes part in the overall tuning of gene expression. Many possible combinations of natural or artificially engineered transcription factors can produce identical enhancer activities,” explains Dr Ilsley.


“We are moving away from having to use an on/off model of gene expression to understand how cell types are specified. Advances in quantitative biology at the single-cell level, like quantitative imaging and RNA sequencing, together with mathematical models, now give biologists the tools they need to delve into the intricacies of gene expression tuning and to predictably manipulate the cell,” concludes Dr Ilsley.

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Baldness and thinning hair are due to aging DNA and elimination of follicle stem cells

Baldness and thinning hair are due to aging DNA and elimination of follicle stem cells | Amazing Science | Scoop.it

Stem cells enable normal cell homeostasis, but they also exist in a quiescent state, ready to proliferate and differentiate after tissue damage. Now, two studies reveal features of stem cells in the hair follicle, an epithelial mini-organ of the skin that is responsible for hair growth and recycling.


During aging, most organs in mammals become smaller (miniaturize) or thinner, and their functions and regenerative capability also decline. Histologically, tissue atrophy and fibrosis are observed in many aged organs. Yet the exact mechanisms for the architectural and functional decline are unknown. Indeed, areas that are as yet underexplored include the dynamics of the constituent cells and their cellular fate, as well as determination of whether aged or damaged cells accumulate or are eliminated in tissues and organs during the aging process.


Organismal aging has been explained by various theories—such as reactive oxygen species, cellular senescence, telomere erosion, and altered metabolism—but not from the viewpoint of cellular and tissue dynamics. Stem cell systems sustain cellular and tissue turnover in most mammalian organs, but it has been difficult to experimentally test the precise fate of somatic stem cells, the cellular pool for tissues and organs. This has limited our understanding of the mechanisms of aging of tissues and organs and the existence of an aging program in mammalian organs. The hair follicle (HF) is an epithelial mini-organ of the skin that sustains cyclic hair regrowth over repeated hair cycles. Hair thinning (senescent baldness) is one of the most typical signs of aging in many long-lived mammals and is often prematurely induced by genomic instability, as in progeroid syndromes.


Wang et al. now found that the Foxc1 transcription factor is induced in activated hair follicle stem cells, which in turn promote Nfatc1 and BMP signaling, to reinforce quiescence.


Matsumura et al. analyzed hair follicle stem cells during aging. They identified type XVII collagen (COL17A1) as key to hair thinning. DNA damage-induced depletion of COL17A1 triggered cell differentiation resulting in the shedding of epidermal keratinocytes from the skin surface. These changes then caused hair follicle shrinkage and hair loss.


Science, this issue p. 559, p. 613;

see also p. 10.1126/science.aad4395

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Mathematics and Art: Hamid Naderi Yeganeh

Mathematics and Art: Hamid Naderi Yeganeh | Amazing Science | Scoop.it

Mathematical artist Hamid Naderi Yeganeh, a student of mathematics at University of Qom in Iran, won the Gold Medal at the 38th Iranian Mathematical Society‘s Competition in May 2014. He creates figures with thousands of mathematical line segments. “The endpoints of each segment are related to the trigonometric functions. We can create many beautiful symmetric figures by this method. Also, there are some interesting asymmetric figures, such as fish,” Hamid explains. Hundreds of stray threads fray at the edges of a mesmerizing geometric tapestry.


Of course, the fields of art and math have long run parallel -- think of the Golden Ratio and M.C. Escher's ever-winding staircases. Yeganeh himself cites Escher's "Reptiles" and "Circle Limit III" as inspirations for his work. Escher's beloved illusions, rooted as they were in mathematical concepts such as tessellation and the more head-scratching idea of hyperbolic geometry, are a testament to how math-oriented art can be.


Though the marriage of the two seemingly separate fields of study is a natural one, Yeganeh's captions for his works are best left to be deciphered by those who studied math beyond the high school level. An illustrious gray-and-purple work featuring soft lines that loop in the shape of a lotus flower bears the considerably less spiritual title, "4,000 Line Segments.

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Absorbing acoustics with soundless spirals

Absorbing acoustics with soundless spirals | Amazing Science | Scoop.it

Researchers at the French National Centre for Scientific Research, CNRS, and the University of Lorraine have recently developed a design for a coiled-up acoustic metasurface which can achieve total acoustic absorption in very low-frequency ranges. "The main advantage is the deep-subwavelength thickness of our absorber, which means that we can deal with very low-frequencies - meaning very large wavelengths - with extremely reduced size structure," said Badreddine Assouar, a principal research scientist at CNRS in Nancy, France.


Assouar and Li, a post-doc in his group at the Institut Jean Lamour, affiliated with the CNRS and the University of Lorraine, describe their work this week in Applied Physics Letters from AIP Publishing.


Acoustic absorption systems work by absorbing sound energy at a resonant frequency and dissipating it into heat. Traditional acoustic absorbers consist of specially perforated plates placed in front of hard objects to form air cavities; however, in order to operate at low frequencies, these systems must also be relatively thick in length, which makes them physically impractical for most applications.


To remedy this, Assouar's group, whose previous work consisted of developing coiled channel systems, designed an acoustic absorber in which sound waves enter an internal coiled air channel through a perforated center hole. This forces the acoustic waves to travel through the channel, effectively increasing the total propagation length of the waves and leading to an effective low sound velocity and high acoustic refractive index. This allows them to make the absorber itself relatively thin, while still maintaining the absorptive properties of a much thicker chamber.


This is made possible because the coiled chamber's acoustic reactance - a property analogous to electrical reactance, a circuit's opposition to a change in voltage or current - compensates for the reactance of the perforated hole and allows for impedance matching to be achieved. This causes all of the acoustic energy to be transferred to the chamber, rather than reflected, and to be ultimately absorbed within the perforated hole.


Further applications of such metasurface may deal with the realization of tunable amplitude and phase profile for acoustic engineering, which would allow for the manipulation of an acoustic wave's propagation trajectory for special applications, such as manipulating particles with a vortex wavefront. Future work for Assouar and his group will include developing the sample fabrication process with 3D printing and subsequent performance analyses.


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Chemical nanocages: New technique advances synthetic biology

Chemical nanocages: New technique advances synthetic biology | Amazing Science | Scoop.it

Living systems rely on a dizzying variety of chemical reactions essential to development and survival. Most of these involve a specialized class of protein molecules—the enzymes.


In a new study, Hao Yan, director of the Center for Molecular Design and Biomimetics at Arizona State University's Biodesign Institute presents a clever means of localizing and confining enzymes and the substrate molecules they bind with, speeding up reactions essential for life processes.


The research, which appears in the current issue of the journal Nature Communications, could have far-reaching applications in fields ranging from improving industrial efficiencies to pioneering new medical diagnostics, guiding targeted drug delivery and producing smart materials. The work also promises to shed new light on particulars of cellular organization and metabolism.


The technique involves the design of specialized, nanometer-scale cages, which self-assemble from lengths of DNA. The cages hold enzyme and substrate in close proximity, considerably accelerating the rate of reactions and shielding them from degradation.


"We have been designing programmable DNA nanostructures with increasing complexity for many years, and it is now time to ask what can we do with these structures," Yan says. "There are numerous other applications from this emerging technology. Through our interdisciplinary collaborative effort, we here describe the use of designer DNA nanocages to compartmentalize enzymatic reactions in a confined environment. Drawing inspiration from Nature, we have uncovered interesting properties, some unexpected."


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Hydrogels can put stem cells to sleep

Hydrogels can put stem cells to sleep | Amazing Science | Scoop.it

Unlike normal cells, stem cells are pluripotent -- they can become any cell type, which makes them powerful potential treatments for diseases such as diabetes, leukemia and age-related blindness. However, maintaining this versatility until the time is right is a major challenge. This week in ACS Central Science, researchers reveal that mimicking a natural process called diapause can halt stem cells, effectively putting them to sleep for up to two weeks.


Recently, scientists have shown that growing pluripotent stem cells (PSCs) on different kinds of surfaces can cause them to differentiate into specific cell types. Based on these observations, Steve Armes, Harry Moore, Irene Canton, Nick Warren and colleagues postulated that the right sort of environment could stop them from differentiating altogether. They were inspired by the fact that certain mammals such as kangaroos can choose to delay gestation, a process known as embryonic diapause, in order to make sure that their offspring are born when conditions are most favorable. Embryos exhibiting diapause are often covered in a soft protective layer of mucus, so the team created very soft hydrogels using a synthetic polymer that mimicked this natural material. When pluripotent stem cells were placed within the hydrogel, the cells essentially stopped growing and differentiating at human body temperature. Cooling turned the gel into a liquid, enabling the stem cells to be easily removed when required. On removal, the cells 'woke up' and began proliferating again within one day. Such hydrogels could be used to store and ship stem cells much more easily and cheaply than at present. Further, the team notes that human embryos also appear to enter diapause when placed in such hydrogels. This suggests that simply creating the right physical environment may be sufficient to delay gestation, which has not previously been observed for human embryos.


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Research Teams Use DNA To Make High-Precision 3-D Nanoparticle Structures

Research Teams Use DNA To Make High-Precision 3-D Nanoparticle Structures | Amazing Science | Scoop.it

DNA strands anchored to the surface of nanoparticles allow researchers to assemble the particles into three-dimensional crystalline lattices. Such control allows researchers to make new materials with desirable properties. In two recent studies, independent teams adapted this approach to gain even more control over assembly.


One team, led by Chad A. Mirkin of Northwestern University, designed “transmutable” DNA-coated nanoparticles that can switch from one lattice structure to another on demand in response to chemical cues (Science 2016, DOI: 10.1126/science.aad2212).


To do that, Mirkin’s team coats the nanoparticle surface with DNA that folds back on itself in hairpin loops. The addition of short oligonucleotides complementary to the loops disrupts the hairpins and exposes a DNA recognition sequence that can bind to sequences on other nanoparticles. By using multiple hairpins that bind to different sequences, the researchers can cycle a given nanoparticle mixture between lattice structures by changing which hairpins are opened or closed.


“Until now, all DNA-programmable nanoparticles have been designed to build one particular structure. To get another structure, you must make a whole new batch of nanoparticles with different DNA linkers attached,” says Sharon C. Glotzer, a materials scientist at the University of Michigan. “With this breakthrough, one can embed multiple potential structures into a single batch of identical nanoparticles and then select the desired structure on demand. The nanoparticles are now transmutable.”


The other team, led by Oleg Gang of Brookhaven National Laboratory, made DNA nanoparticle structures with the same crystal lattice as diamond (Science 2016, DOI: 10.1126/science.aad2080). Scientists have been trying to make this structure for decades, Gang says. His team succeeded by combining DNA-coated nanoparticles with tetrahedral cages made with DNA origami. Short, single-stranded DNA sequences on the tetrahedron bind to the DNA coating on the particles. One nanoparticle is trapped inside each tetrahedron; four others are attached to the vertices of the tetrahedron, mimicking the geometry of carbon in diamond.


Gang’s strategy marks the first time DNA origami has been combined with DNA-mediated nanoparticle assembly, Glotzer notes. Such an approach will lead to more complex assemblies than are accessible by more traditional approaches alone, she says.


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Man-made global warming effects will play out over next 10,000 years

Man-made global warming effects will play out over next 10,000 years | Amazing Science | Scoop.it

A large group of climate scientists has made a bracing statement in the journal Nature Climate Change, arguing that we are mistaken if we think global warming is only a matter of the next 100 years or so — in fact, they say, we are locking in changes that will play out over as many as 10,000 years.


“The next few decades offer a brief window of opportunity to minimize large-scale and potentially catastrophic climate change that will extend longer than the entire history of human civilization thus far,” write the 22 climate researchers, led by Peter Clark, from Oregon State University.

The author names include not only a number of very influential climate scientists in general but several key leaders behind major reports from the United Nations’ Intergovernmental Panel on Climate Change, including MIT’s Susan Solomon and Thomas Stocker of the University of Bern in Switzerland.


The researchers’ key contention is that we have been thinking about climate change far too narrowly by only projecting outward to the year 2100, which the research says “was originally driven by past computational capabilities.” Rather, we should consider that the long-term consequences of human emissions for global temperatures and sea level will play out over many millennia.


“It’s a statement of worry,” said Raymond Pierrehumbert, a geoscientist at Oxford University and one of the study’s authors. “And actually, most of us who have worked both on paleoclimate and the future have been terrified by the idea of doubling or quadrupling CO2 right from the get-go.”


“In hundreds of years from now, people will look back and say, yeah, the sea level is rising, it will continue to rise, we live with a constant rise of sea level because of these people 200 years ago that used coal, and oil, and gas,” said Anders Levermann, a sea level rise expert at the Potsdam Institute for Climate Impact Research and one of the paper’s authors. “If you just look at this, it’s stunning that we can make such a long-lasting impact that has the same magnitude as the ice ages.”


The key reason for this is that carbon dioxide stays in the atmosphere for a very long time before being slowly removed again by natural processes. “A considerable fraction of the carbon emitted to date and in the next 100 years will remain in the atmosphere for tens to hundreds of thousands of years,” the study noted. Meanwhile, the planet’s sea levels adjust gradually to its rising temperature over thousands of years.


So what will the world look like in 10,000 years, thanks to us? That really depends on what we do in the next few hundred years with the fossil fuels to which we have relatively easy access. It also depends on whether or not we develop technologies that are capable of pulling carbon dioxide out of the air on a massive scale, comparable to the amount that we’re currently emitting.


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Room-temperature lithium metal battery closer to reality

Room-temperature lithium metal battery closer to reality | Amazing Science | Scoop.it

Rechargeable lithium metal batteries have been known for four decades to offer energy storage capabilities far superior to today's workhorse lithium-ion technology that powers our smartphones and laptops. But these batteries are not in common use today because, when recharged, they spontaneously grow treelike bumps called dendrites on the surface of the negative electrode.


Over many hours of operation, these dendrites grow to span the space between the negative and positive electrode, causing short-circuiting and a potential safety hazard.


Current technology focuses on managing these dendrites by putting up a mechanically strong barrier, normally a ceramic separator, between the negative and the positive electrodes to restrict the movement of the dendrite. The relative non-conductivity and brittleness of such barriers, however, means the battery must be operated at high temperature and are prone to failure when the barrier cracks.


But a Cornell team, led by chemical and biomolecular engineering professor Lynden Archer and graduate student Snehashis Choudhury, proposed in a recent study that by designing nanostructured membranes with pore dimensions below a critical value, it is possible to stop growth of dendrites in lithium batteries at room temperature. "The problem with ceramics is that this brute-force solution compromises conductivity," said Archer, the William C. Hooey Director and James A. Friend Family Distinguished Professor of Engineering and director of the Robert Frederick Smith School of Chemical and Biomolecular Engineering.


"This means that batteries that use ceramics must be operated at very high temperatures – 300 to 400 degrees Celsius [572 to 752 degrees Fahrenheit], in some cases," Archer said. "And the obvious challenge that brings is, how do I put that in my iPhone?" You don't, of course, but with the technology that the Archer group has put forth, creating a highly efficient lithium metal battery for a cellphone or other device could be reality in the not-too-distant future.


Archer credits Choudhury with identifying the polymer polyethylene oxide as particularly promising. The idea was to take advantage of "hairy" nanoparticles, created by grafting polyethylene oxide onto silica to form nanoscale organic hybrid materials (NOHMs), materials Archer and his colleagues have been studying for several years, to create nanoporous membranes.


To screen out dendrites, the nanoparticle-tethered PEO is cross-linked with another polymer, polypropylene oxide, to yield mechanically robust membranes that are easily infiltrated with liquid electrolytes. This produces structures with good conductivity at room temperature while still preventing dendrite growth. "Instead of a 'wall' to block the dendrites' proliferation, the membranes provided a porous media through which the ions pass, with the pore-gaps being small enough to restrict dendrite penetration," Choudhury said. "With this nanostructured electrolyte, we have created materials with good mechanical strength and good ionic conductivity at room temperature."

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What people and their domesticated animals ate 30,000 years ago

What people and their domesticated animals ate 30,000 years ago | Amazing Science | Scoop.it

Biogeologists have shown how Gravettian people shared their food 30,000 years ago. Around 30,000 years ago Predmosti was inhabited by people of the pan-European Gravettian culture, who used the bones of more than 1000 mammoths to build their settlement and to ivory sculptures. Did prehistoric people collect this precious raw material from carcasses -- easy to spot on the big cold steppe -- or were they the direct result of hunting for food?

Předmostí I is an exceptional prehistoric site located near Brno in the Czech Republic. Around 30,000 years ago it was inhabited by people of the pan-European Gravettian culture, who used the bones of more than 1,000 mammoths to build their settlement and to ivory sculptures. Did prehistoric people collect this precious raw material from carcasses -- easy to spot on the big cold steppe -- or were they the direct result of hunting for food? This year-round settlement also yielded a large number of canids remains, some of them with characteristics of Palaeolithic dogs. Were these animals used to help hunt mammoths?

To answer these two questions, Tübingen researcher Hervé Bocherens and his international team carried out an analysis of carbon and nitrogen stable isotopes in human and animal fossil bones from the site. Working with researchers from Brno and Brussels, the researchers were able to test whether the Gravettian people of Předmostí ate mammoth meat and how the "palaeolithic dogs" fit into this subsistence picture.

They found that humans did consume mammoth -- and in large quantities. Other carnivores, such as brown bears, wolves and wolverines, also had access to mammoth meat, indicating the high availability of fresh mammoth carcasses, most likely left behind by human hunters. Surprisingly, the dogs did not show a high level of mammoth consumption, but rather consumed essentially reindeer meat that was not the staple food of their owners. A similar situation is observed in traditional populations from northern regions, who often feed their dogs with the food that they do not like. These results also suggest that these early dogs were restrained, and were probably used as transportation helpers.

These new results provide clear evidence that mammoth was a key component of prehistoric life in Europe 30,000 years ago, and that dogs were already there to help.

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AI: Machine learning helps discover the most luminous supernova in history

AI: Machine learning helps discover the most luminous supernova in history | Amazing Science | Scoop.it
Machine-learning technology developed at Los Alamos National Laboratory played a key role in the discovery of supernova ASASSN-15lh, an exceptionally powerful explosion that was 570 billion times brighter than the sun and more than twice as luminous as the previous record-holding supernova. This extraordinary event marking the death of a star was identified by the All Sky Automated Survey for SuperNovae (ASAS-SN) and is described in a new study published today in Science.


"This is a golden age for studying changes in astronomical objects thanks to rapid growth in imaging and computing technology," said Przemek Wozniak, the principal investigator of the project that created the software system used to spot ASASSN-15lh. "ASAS-SN is a leader in wide-area searches for supernovae using small robotic telescopes that repeatedly observe the same areas of the sky looking for interesting changes."


ASASSN-15lh was first observed in June 2015 by twin ASAS-SN telescopes¾just 14 centimeters in diameter¾located in Cerro Tololo, Chile. While supernovae already rank among the most energetic explosions in the universe, this one was 200 times more powerful than a typical supernova. The event appears to be an extreme example of a "superluminous supernova," a recently discovered class of rare cosmic explosions, most likely associated with gravitational collapse of dying massive stars. However, the record-breaking properties of ASASSN-15lh stretch even the most exotic theoretical models based on rapidly spinning neutron stars called magnetars.


"The grand challenge in this work is to select rare transient events from a deluge of imaging data in time to collect detailed follow-up observations with larger, more powerful telescopes," said Wozniak. "We developed an automated software system based on machine-learning algorithms to reliably separate real transients from bogus detections." This new technology will soon enable scientists to find ten or perhaps even hundred times more supernovae and explore truly rare cases in great detail. Since January 2015 this capability has been deployed on a live data stream from ASAS-SN.


Los Alamos is also developing high-fidelity computer simulations of shock waves and radiation generated in supernova explosions. As explained by Chris Fryer, a computational scientist at Los Alamos who leads the supernova simulation and modeling group, "By comparing our models with measurements collected during the onset of a supernova, we will learn about the progenitors of these violent events, the end stages of stellar evolution leading up to the explosion, and the explosion mechanism itself."


The next generation of massive sky monitoring surveys is poised to deliver a steady stream of high-impact discoveries like ASASSN-15lh. The Large Synoptic Survey Telescope (LSST) expected to go on sky in 2022 will collect 100 Petabytes (100 million Gigabytes) of imaging data. The Zwicky Transient Facility (ZTF) planned to begin operations in 2017 is designed to routinely catch supernovae in the act of exploding. However, even with LSST and ZTF up and running, ASAS-SN will have a unique advantage of observing the entire visible sky on daily cadence. Los Alamos is at the forefront of this field and well prepared to make important contributions in the future.

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Einstein’s Gravitational Waves Detected Originating from Merging Black Holes 1.3 Billion Years Ago

Einstein’s Gravitational Waves Detected Originating from Merging Black Holes 1.3 Billion Years Ago | Amazing Science | Scoop.it
Today, scientists announced that, for the first time in history, gravitational waves have been detected.

Gravitational waves are ripples in spacetime throughout the universe. What’s truly remarkable about this discovery is that Albert Einstein predicted the existence of gravitational waves 100 years ago, but scientists have never been able to detect them, until now.

The discovery came out of the U.S. based Laser Interferometer Gravitational Wave Observatory (LIGO). The mission of LIGO was to directly measure gravitational waves. In order to do that, LIGO scientists needed to construct the most precise measuring device the world had ever seen.

The LIGO project, which began in 1992, was the largest scientific investment the National Science Foundation (NSF) has ever made.

At an NSF press conference this morning, LIGO Laboratory Executive Director, David Reitze, said “This was a scientific moon shot. And we did it – we landed on the moon.”


LIGO consists of two 4 kilometer (2.5 mile) tunnels located in Louisiana and the state of Washington. Because gravitational waves stretch space in one direction and compress space in the other, LIGO was designed to measure changes in length across large land distances. If they could detect a stretch of land in the LIGO tunnels in one direction and compression in the other, they could theoretically detect a gravitational wave.


The “ruler” that scientists used to measure these tunnel lengths was the speed of light. The speed of light is constant, so LIGO can determine the length of the tunnels by measuring the time it takes for a laser to bounce from one end of the tunnel to the other.


Gravitational waves are created when masses accelerate. Measured back on September 14th, 2015, the gravitational wave signal that the LIGO scientists detected matches the exact signal they’d expect from two merging black holes accelerating at half the speed of light.


Reitze explained that the black holes that created this gravitational wave merged 1.3 billion years ago. It took that long for the wave to travel to the Earth. Each of the black holes were 30 times the mass of the sun and were accelerating at half the speed of light when they collided into each other. The ability to measure gravitational waves will open up an entirely new window for astronomy. Reitze explained that this will enable scientists to look at the universe in a new way.


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An evolutionary approach to AI learning

An evolutionary approach to AI learning | Amazing Science | Scoop.it
Researchers develop AI that can learn how best to achieve its goals, but do we need to step back a bit and think first about the implications?


AI guru Nick Bostrom frequently highlights the crucial importance of the goal setting process when building a superintelligence.  He outlines the complexities involved in doing this, with the many unintended consequences that lie in wait for us. Despite the perilous nature of such work, it’s increasingly likely that automations will have such an end goal and then freedom over how they achieve that.  Recent work by researchers at the University of California, Berkeley revolves around setting such a goal and devising algorithms that successfully attain it.


Bostrom suggests that this can be averted by giving the AI an overarching goal of friendliness, although even that is not without difficulty. “How exactly friendliness should be understood and how it should be implemented, and how the amity should be apportioned between different people and nonhuman creatures is a matter that merits further consideration,” he says.


We’re reaching the stage where AI is increasingly capable of doing fantastical things.  Now is perhaps the time to address just how we’d like it to do that before we reach a point where such deliberations are too late.

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Japanese Robotic Farm's First Harvest Next Year—Half a Million Lettuces a Day

Japanese Robotic Farm's First Harvest Next Year—Half a Million Lettuces a Day | Amazing Science | Scoop.it

In modern times, farming's gone from humanity's top job to a sliver of the economy—a trend that continues today as fewer young people choose to farm. For every farmer under 35 there are 6 over 65, and a quarter of today's US farmers will retire by 2030. But we all still have to eat. One wonders: "If there are no new farmers, who will grow our food?"


Robots, of course. One recent example? Japan's new automated indoor lettuce farmGrowing lettuce isn't the flashiest occupation, but it gets a little flashier when you do it with the press of a button.Japanese company Spread is expanding its indoor farm and more fully automating it. People will plant the seeds, but a robotic system takes it from there. Conveyor belts equipped with robot arms will water, trim, re-plant, and harvest crops. Sensors will monitor humidity, CO2, light, and temperature—automatically adjusting the indoor climate to make sure the lettuce is happy.


“The seeds will still be planted by humans, but every other step, from the transplanting of young seedlings to larger spaces as they grow to harvesting the lettuces, will be done automatically,” according to JJ Price, Spread’s global marketing managerCompared to their current indoor farm, Spread's new facility aims to reduce energy costs by a third with LEDs. Automation will reduce labor costs by half, and by recycling 98% of their water, Spread says their pesticide-free lettuce consumes 100 times less than conventionally grown lettuce.

Once operational next year, the farm will more than double production from 21,000 heads of a lettuce a day to 50,000 a day, and they're aiming for half a million a day in five years. While indoor farms offer a more controlled setting, farm robots aren't limited to them.


Self-driving tractors have been in fields for years. A farmer usually has to be in the cab, but they can focus their attention elsewhere, doing business on a laptop for example. (And full autonomy is coming.) Other kinds of farm robots abound. Robot arms can prune plants or spot and pick ripe fruit. Autonomous drones can skim fields and monitor crop health from above. All this farm automation isn't new; it's the continuation of a long trend. Robots will take over some jobs from people, but fewer of us are choosing to farm too. If your focus is elsewhere, no problem, farm robots like these ones will make sure you still eat your greens.


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Russia uses 3D printing technology for the production of colossal T-14 Armata tanks

Russia uses 3D printing technology for the production of colossal T-14 Armata tanks | Amazing Science | Scoop.it
Electromashina JSC, a manufacturer of armored vehicles for the Russian army, has revealed that it is using an industrial 3D printer to produce an Armata tank, the standard next-generation armored vehicle platform of the Russian military.


When Russia’s impressive T-14 Armata tank first hit the streets of Moscow last year, very little was known about it. The armored vehicle drove around Red Square during the May 2015 Victory Day Parade, a celebration of the 70th anniversary of Russia’s victory in WWII. Drivers showed off the Armata’s impressive turn radius, its radar-baffling paint, and its thick armor plates. Now, information has been released about how certain Armata tanks, perhaps including the T-14, are being manufactured. Electromashina JSC, an armored vehicle manufacturer and part of the UralVagonZavod corporation, has revealed the important role played by 3D printing technology in the production of its new line of Armata tanks.


Anton Ulrich, Manager of the Rapid Prototyping Lab at Electromashina, explained how 3D printing has been used since 2015 to produce prototype parts. These parts can be created in small numbers, tested, and then redesigned as appropriate until ready for series production. Electromashina has also been using its 3D printers to produce master models, used in the casting of metal and plastic parts. In the near future, the company will start using 3D printers to produce 3D printed titanium parts, several meters in length, for use in its armored vehicles.


“3D printing has been implemented to speed up trial production,” Ulrich explained. “When a designer develops new products, he uses CAD software to produce a 3D model. So, using a 3D printer, we can quickly turn those 3D models into prototype parts. Now there is no need to order a sample component, and then, realizing that it doesn’t fit, have to order a re-run and waste metal. Furthermore, it is possible to produce not just small elements of a part, but the whole assembly, evaluating its mechanical characteristics before production.”


Although 3D printing machine-ready components for use in armored vehicles and other military equipment is a distinct possibility for Electromashina, these items would have to meet certain requirements of the defense industry. “3D printed components can go straight to consumers in certain industries,” said Ulrich. “But in the defense industry, standards are much higher.”


Ulrich, however, sees no reason why 3D printed components cannot eventually meet those strict defense industry requirements. He cites the cases of 3D printed components being used in the aerospace industry and even produced in space on the International Space Station. If 3D printed parts can be approved for use in space, they could certainly be deemed fit for use in Russian tanks.


The Russian army plans to acquire 2,300 T-14 Armata tanks between now and 2020.

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We Have the Technology to Destroy All Zika Virus Spreading Mosquitoes

We Have the Technology to Destroy All Zika Virus Spreading Mosquitoes | Amazing Science | Scoop.it

A controversial genetic technology able to wipe out the mosquito carrying the Zika virus will be available within months, scientists say. The technology, called a “gene drive,” was demonstrated only last year in yeast cells, fruit flies, and a species of mosquito that transmits malaria. It uses the gene-snipping technology CRISPR to force a genetic change to spread through a population as it reproduces.


Three U.S. labs that handle mosquitoes, two in California and one in Virginia, say they are already working toward a gene drive for Aedes aegypti, the type of mosquito blamed for spreading Zika. If deployed, the technology could theoretically drive the species to extinction.

“We could have it easily within a year,” says Anthony James, a molecular biologist at the University of California, Irvine.


Any release of a gene drive in the wild would be hotly debated by ecologists. So far, no public health agency has thrown its weight behind the idea. But with Zika sowing fear across Latin America and beyond, the technology is likely to get a closer look. “Four weeks ago we were trying to justify why we are doing this. Now they’re saying ‘Get the lead out,’” says James. “It’s absolutely going to chan­­­­­­­­­ge the conversation.”


The Zika virus is now spreading “explosively" in the Americas, according to the World Health Organization, which last week declared a global health emergency. While the virus causes only a mild rash, the epidemic is frightening because of a suspected link to 4,000 children born in Brazil with microcephaly, or shrunken heads.


There’s no easy way to stop Zika. There is no vaccine and developing one could take several years. Brazil is sending 220,000 soldiers door-to-door to check for mosquitoes breeding in old tires and swimming pools. Women are being asked to delay pregnancy. Gene-drive technology could be ready sooner than a vaccine, but it’s no quick fix, either, scientists caution. Self-annihilating mosquitoes will first have to undergo tests in the lab, then perhaps on an island, before they could be released more broadly. Regulations and public debate could stretch the time line out for years.


The Aedes aegypti mosquito is not native to the Americas. It’s an invasive species that is now found from Florida to Argentina and whose range could expand with climate change. In addition to the Zika virus, its bite also transmits the chikinguya and dengue viruses. Dengue fever causes 100 million people to fall ill each year. Because of the extent of the problems Aedesaegypti causes, some scientists favor using advanced technology to drive the species to extinction, at least in the Americas. “These mosquitoes truly have little value,” says Zach Adelman, an entomologist at Virginia Tech who works with Aedes aegypti. “People in favor of eradication are going to be able to plead their case.”

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Corie Rosen's curator insight, February 10, 11:15 PM

I hate mosquitoes as much as the next person, but from an ecological perspective, this is not a good idea. The Aedes aegypti does cause a lot of damage and suffering, and that is truly awful, but who are we to play God? Why should we decide what species lives and dies? As much as we hate them, mosquitoes provide an ecological niche. Even Aedes aegypti does. Even if we wipe them out, there is no telling what the consequences of that will be. Mother Nature may unleash a creature even worse than Aedes aegypti to take over that niche, and we don’t want or need that to happen! There is also the possibility of these mosquitoes becoming resistant to genetic modification. Should that end up happening, then what would we be left with? The problem is that we just don’t know, nor can scientists predict, what would happen if we go through with this, and that is scary!

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Hundreds of galaxies found hiding behind the Milky Way

Hundreds of galaxies found hiding behind the Milky Way | Amazing Science | Scoop.it

Astronomers in Australia have confirmed the discovery of hundreds of galaxies hidden by the Milky Way and a gravitational anomaly known as the Great Attractor.


Until now, the galaxy-rich region of space some 250 million light-years away has been obscured by the stars and dust of the Milky Way. "The Milky Way is very beautiful of course and it's very interesting to study our own galaxy but it completely blocks out the view of the more distant galaxies behind it," Lister Staveley-Smith, a professor at the University of Western Australia, said in a press release.


A new receiver installed on the Parkes radio telescope has allowed astronomers for the first time to see through the foreground fuzz of the Milky Way's starry dust and into the hidden portions of the Great Attractor region. Previous measurements suggest the Milky Way and several hundred other galaxies are being pulled toward the Great Attractor region by a gravitational force as powerful as a million billion suns. But researchers aren't exactly sure why.


"We know that in this region there are a few very large collections of galaxies we call clusters or superclusters, and our whole Milky Way is moving towards them at more than two million kilometers per hour," Staveley-Smith said. But the new findings -- detailed in the Astrophysical Journal -- have revealed several structures that might offer clues to the nature of the Great Attractor region's magnetism.


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Researchers discover a genetic mutation (SLIC19A3) that prevents diabetes complications 

Researchers discover a genetic mutation (SLIC19A3) that prevents diabetes complications  | Amazing Science | Scoop.it
A number of complications are associated with diabetes, but they are more prevalent in some patients than in others. A Finnish study has now revealed two genetic mutations which seem to lower the risk of contracting a diabetic retinal or kidney disease.

The most significant complications of diabetes include diabetic retinal disease, or retinopathy, and diabetic kidney disease, or nephropathy. Both involve damaged capillaries. The biggest risk factor associated with damage to the tiny blood vessels is high blood sugar, although genetic factors are also at play. Experiments conducted on both individual cells and laboratory animals indicate that the presence of vitamin B1 inside the cell can prevent the damage caused by high blood sugar.

Together with Professor Massimo Porta from the University of Turin, Professor Per-Henrik Groop, Principal Investigator of the FinnDiane research project at the University of Helsinki and Folkhälsan Research Centre, and his research group have studied the impact of point mutations on the genes that encode the proteins which transfer vitamin B1 into cells. The research was based on the hypothesis that the studied mutations impact the individual’s capacity to transfer vitamin B1 into cells and consequently the susceptibility for additional complications associated with diabetes.

The research used the world’s most extensive research data set of type 1 diabetes patients, compiled by Groop’s group, in which the patients are characterised based on their genetic profile and the severity of their diabetes complications. The results showed that two of the studied point mutations in the SLC19A3 gene were strongly associated with both retinopathy and the combination of retinopathy and nephropathy; thus, carriers of the genetic variant were less likely to have these complications. The protective effect of the variant remained significant even when other common risk factors were taken into account.

The study was repeated on North American patient data, and the results confirmed that the two variants protect their carriers from the combination of retinopathy and nephropathy. “Based on these results, it seems that the SLC19A3 gene has a role in the development of diabetic nephropathy and diabetic retinopathy. The results also help explain why some patients with type 1 diabetes are more likely to develop complications than others," says Iiro Toppila, the researcher responsible for analysing the data.  “However, further research is needed into the biological effects of point mutations.”

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Tick genome reveals secrets of a successful bloodsucker

Tick genome reveals secrets of a successful bloodsucker | Amazing Science | Scoop.it

With tenacity befitting their subject, an international team of nearly 100 researchers toiled for a decade and overcame tough technical challenges to decipher the genome of the blacklegged tick (Ixodes scapularis)The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, contributed primary support to the research, which appears in the online, open-access journal Nature Communications.


“Ticks spread more different kinds of infectious microbes to people and animals than any other arthropod group,” said NIAID Director Anthony S. Fauci, M.D. “The spiral-shaped bacterium that causes Lyme disease is perhaps the best known microbe transmitted by ticks; however, ticks also transmit infectious agents that cause human babesiosis, anaplasmosis, tick-borne encephalitis and other diseases. The newly assembled genome provides insight into what makes ticks such effective disease vectors and may generate new ways to lessen their impact on human and animal health.”


Catherine A. Hill, Ph.D., of Purdue University, headed the team of investigators. Aside from the logistical challenges of coordinating activities of dozens of workers across many time zones, the researchers’ focus was a creature that is extremely difficult to maintain and that lives a long time — up to two years in the wild and nine months in the lab, Dr. Hill noted. Ixodes ticks have three blood-feeding life stages, and during each one, they feed on a different vertebrate animal. During feeding, ticks ingest blood for hours or days at a time. After mating, adult female ticks rapidly imbibe a large blood meal during which they expand hugely. “Because genes may switch on or off depending on the life stage of the tick, we needed to culture and collect ticks at each stage for analysis. This was not easy to do,” said Dr. Hill.


Another challenge was the sheer size of the tick genome — some 2.1 billion DNA base pairs — and expansive regions where sequences are repeated. “The degree of DNA repetition — approximately 70 percent of the total — made assembling the full genome in the correct order very difficult,” Dr. Hill said. In the end, the team determined the order and sequence of about two-thirds of the total genome. “We determined the sequence for 20,486 protein-coding genes,” she said, “of which 20 percent may be unique to ticks. Those tick-specific genes are like guideposts that say ‘start here’ as we look for new ways to counter infectious ticks.”


Although the latest research represents just a first look at the tick genome, the scientists have already identified genes and protein families that shed light on why Ixodes ticks succeed so well as parasites and hint at the reasons they excel at spreading pathogens, Dr. Hill noted. For example, compared with other blood-feeders, ticks have many more proteins devoted to consuming, concentrating and detoxifying their iron-containing food. Although mosquitoes — which quickly siphon up relatively small amounts of blood through a tube-like mouthpiece — have several proteins dedicated to blood digestion, ticks have many more proteins involved in this process. Other genes code for proteins that help ticks concentrate the blood and rapidly excrete excess water that accompanies large blood meals. Still other genes allow ticks to quickly expand their stiff outer coats to accommodate a 100-fold increase in total body size during blood feeding.


Other peculiarities of the tick’s lifestyle reflected in the genome include genes associated with the multifaceted sensory systems that the parasite uses when “questing” for a host during each of its separate blood-feeding stages. Compared with mosquitoes, ticks appear to have fewer genes used to detect hosts, and, unlike a mosquito’s “smell” receptors, ticks may use “taste” receptors to locate their food sources. Each of the newly identified proteins is a potential target for new, tick-specific interventions, explained Dr. Hill. “The genome gives us a code book to the inner workings of ticks. With it, we can now begin to hack their system and write a counter-script against them.”


In an effort to explain variations in Lyme disease prevalence across the United States, the team also examined genetic diversity within and among I. scapularis populations gathered from five states in the Northeast and Midwest and three in the South. Some have speculated that ticks in the Northeast and Midwest spread the bacteria that cause Lyme disease more easily than those in the South, or that the two populations perhaps comprise separate species. The genetic analysis showed that there is only one species of I. scapularis, said Dr. Hill, but subtle genetic differences were detected, and these may help explain some of the variance in the ability of populations to transmit disease and, therefore, affect disease prevalence.

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Cyanobacteria see like tiny little eyeballs

Cyanobacteria see like tiny little eyeballs | Amazing Science | Scoop.it
Biologists discover how bacteria sense light and move towards it: the entire single-cell organism focuses light like a tiny eyeball.


Cyanobacteria, including the Synechocystis species used in the study, are an ancient and abundant lifeform. They live in water and get their energy from photosynthesis - which explains their enthusiasm for bright light. "It has a way of detecting where the light is; we know that because of the direction that it moves. But we were puzzled about this because the cells are very, very small," said study co-author Conrad Mullineaux, from Queen Mary University of London.


The researchers used a laser beam to probe exactly how such focused light affected the bugs' behavior. With the laser beam trained steadily on the centre of a dish, the team shone a bigger, separate light on the Synechocystis cells from one side. This drew the little critters across the surface in the usual way, pulling themselves towards the light with tiny tentacles. The usual bright "image" of the light was visible, focused on their trailing side. But the moment any of the bugs strayed into the laser beam, there was an abrupt about-face. "When they hit it, they bounced off it," Prof Mullineaux said. "As soon as the laser was hitting one side of the cell, the cells moved away. They switched direction."


In other words, bright light focused on one side of the bacterium definitely does drive it to run the other way - which under normal circumstances takes it towards the source of the light. In fact, because some amount of light is hitting the cell from all around, the team says that each microbe will have a "360-degree image" of its surroundings focused on the inside of its cell membrane. That image is very fuzzy - with a resolution of about 21 degrees, compared to the 0.02-degree precision of our eyes - but it is enough for photoreceptor molecules, embedded in the cell membrane, to guide the bug's movement.

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Alcaline ocean on Enceladus - could it harbor life?

Alcaline ocean on Enceladus - could it harbor life? | Amazing Science | Scoop.it
Recently, geochemist Christopher Glein led a team that developed a new approach to estimating the pH of Enceladus' ocean using observational data of the carbonate geochemistry of plume material. This is a classic problem in geochemical studies of Earth (such as rainwater), but scientists can now solve the carbonate problem on an extraterrestrial body thanks to measurements of dissolved inorganic carbon by the Cosmic Dust Analyzer (CDA), and carbon dioxide gas by the Ion and Neutral Mass Spectrometer (INMS) onboard Cassini.
Glein's team tried to create the most comprehensive chemical model to date of the ocean by accounting for compositional constraints from both INMS and CDA, such as the salinity of the plume. Their model suggests that Enceladus has a sodium, chloride and carbonate ocean with an alkaline pH of 11 or 12, close to the equivalent of ammonia or soapy water. The estimated pH is slightly higher by 1 to 2 units than an earlier estimate based on CDA data alone, but the different modeling approaches are consistent in terms of the overall chemistry of an alkaline ocean.
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Good Sci-Fi fodder...

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Energy-friendly chip for mobile devices can perform powerful artificial-intelligence tasks

Energy-friendly chip for mobile devices can perform powerful artificial-intelligence tasks | Amazing Science | Scoop.it
MIT researchers have developed a new chip designed to implement neural networks. It is 10 times as efficient as a mobile GPU, so it could enable mobile devices to run powerful artificial-intelligence algorithms locally, rather than uploading data to the Internet for processing.


In recent years, some of the most exciting advances in artificial intelligence have come courtesy of convolutional neural networks, large virtual networks of simple information-processing units, which are loosely modeled on the anatomy of the human brain.


Neural networks are typically implemented using graphics processing units (GPUs), special-purpose graphics chips found in all computing devices with screens. A mobile GPU, of the type found in a cell phone, might have almost 200 cores, or processing units, making it well suited to simulating a network of distributed processors.


At the International Solid State Circuits Conference in San Francisco this week, MIT researchers presented a new chip designed specifically to implement neural networks. It is 10 times as efficient as a mobile GPU, so it could enable mobile devices to run powerful artificial-intelligence algorithms locally, rather than uploading data to the Internet for processing.


Neural nets were widely studied in the early days of artificial-intelligence research, but by the 1970s, they’d fallen out of favor. In the past decade, however, they’ve enjoyed a revival, under the name “deep learning.”


“Deep learning is useful for many applications, such as object recognition, speech, face detection,” says Vivienne Sze, the Emanuel E. Landsman Career Development Assistant Professor in MIT's Department of Electrical Engineering and Computer Science whose group developed the new chip. “Right now, the networks are pretty complex and are mostly run on high-power GPUs. You can imagine that if you can bring that functionality to your cell phone or embedded devices, you could still operate even if you don’t have a Wi-Fi connection. You might also want to process locally for privacy reasons. Processing it on your phone also avoids any transmission latency, so that you can react much faster for certain applications.”


The new chip, which the researchers dubbed “Eyeriss,” could also help usher in the “Internet of things” — the idea that vehicles, appliances, civil-engineering structures, manufacturing equipment, and even livestock would have sensors that report information directly to networked servers, aiding with maintenance and task coordination. With powerful artificial-intelligence algorithms on board, networked devices could make important decisions locally, entrusting only their conclusions, rather than raw personal data, to the Internet. And, of course, onboard neural networks would be useful to battery-powered autonomous robots.

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'Cannibalism' between stars

'Cannibalism' between stars | Amazing Science | Scoop.it

Stars are born inside a rotating cloud of interstellar gas and dust, which contracts to stellar densities thanks to its own gravity. Before finding itself on the star, however, most of the cloud lands onto a circumstellar disk forming around the star owing to conservation of angular momentum. The manner in which the material is transported through the disk onto the star, causing the star to grow in mass, has recently become a major research topic in astrophysics.


It turned out that stars may not accumulate their final mass steadily, as was previously thought, but in a series of violent events manifesting themselves as sharp stellar brightening. The young FU Orionis star in the constellation of Orion is the prototype example, which showed an increase in brightness by a factor of 250 over a time period of just one year, staying in this high-luminosity state now for almost a century.

One possible mechanism that can explain these brightening events was put forward 10 years ago by Eduard Vorobyov, now working at the Astrophysical Department of the Vienna University, in collaboration with Shantanu Basu from the University of Western Ontario, Canada.


According to their theory, stellar brightening can be caused by fragmentation due to gravitational instabilities in massive gaseous disks surrounding young stars, followed by migration of dense gaseous clumps onto the star. Like the process of throwing logs into a fireplace, these episodes of clump consumption release excess energy which causes the young star to brighten by a factor of hundreds to thousands. During each episode, the star is consuming the equivalent of one Earth mass every ten days. After this, it may take another several thousand years before another event occurs.


Eduard Vorobyov describes the process of clump formation in circumstellar disks followed by their migration onto the star as "cannibalism on astronomical scales". These clumps could have matured into giant planets such as Jupiter, but instead they were swallowed by the parental star. This invokes an interesting analogy with the Greek mythology, wherein Cronus, the leader of the first generation of Titans, ate up his newborn children (though failing to gobble up Zeus, who finally brought death upon his father).


With the advent of advanced observational instruments, such as SUBARU 8.2 meter optical-infrared telescope installed in Mauna Kea (Hawaii), it has become possible for the first time to test the model predictions. Using high-resolution, adaptive optics observations in the polarized light, an international group of astronomers led by Hauyu Liu from European Space Observatory (Garching, Germany) has verified the presence of the key features associated with the disk fragmentation model -- large-scale arms and arcs surrounding four young stars undergoing luminous outbursts, including the prototype FU Orionis star itself. The results of this study were accepted for publication in Science Advances.


"This is a major step towards our understanding of how stars and planets form and evolve", says Vorobyov, "If we can prove that most stars undergo such episodes of brightening caused by disk gravitational instability, this would mean that our own Sun might have experienced several such episodes, implying that the giant planets of the Solar system may in fact be lucky survivors of the Sun's tempestuous past".


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Gloop from the deep sea: The unusual secretions of the hagfish

Gloop from the deep sea: The unusual secretions of the hagfish | Amazing Science | Scoop.it

ETH scientists are researching the unusual secretions of the hagfish. Over the next three years, the researchers will try to find out how this natural hydrogel can be harnessed for human use.


This animal has done everything right. It has been around for 300 million years, outlived the dinosaurs and survived the catastrophic meteorite impact, warm phases and glacial periods. Even today, it continues to populate the sea at depths where it eats carrion and hunts prey. The Atlantic hagfish (Myxine glutinosa) is not really attractive at first glance. In fact, most people probably consider it quite disgusting. Nevertheless, the hagfish – or rather its slime – has caught the attention of a group of ETH researchers at the Laboratory of Food Process Engineering.


The slime of the hagfish is an extraordinary defense mechanism. When a hagfish is attacked by a predator, it secretes a glandular exudate that gels within a split second and forms a massive slime mass – even in cold water. This slime immobilizes vast amounts of water, forming a dilute, viscous and cohesive network. Fish attempting to attack the hagfish may then suffocate on the slime and thus let go of the hagfish.


Preliminary research quickly revealed to the scientists that there had been little examination of the structure of the slime and how it is formed and secreted. The scientific community knows that the natural hydrogel produced by the hagfish has two main components: 15- to 30-cm-long protein threads and mucin, which sits between the threads and makes the slime “slimy”. The protein threads have properties similar to spider silk. According to Kuster, the threads are extremely tear-resistant and elastic, though only when moist.


The slime consists of almost 100 % water and contains just 0.004 % gelling agent. In other words, the weight ratio of gelling agent to water is 26,000-fold, which is over 200 times more than in conventional animal gelatine. Furthermore, very little energy is required for the gelling process.


The ETH researchers were especially fascinated by the fact that the protein filaments have the form of a sphere measuring 150 micrometers in diameter while still in the glands, but once they are part of the slime they extend to threads of several centimeters in length. How the threads unwind from the sphere is not yet understood in depth. "The way the threads coil within the cells is highly specialized and very unusual," says Böni.

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