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  • richardmitnick 10:27 am on July 12, 2017 Permalink | Reply
    Tags: , , , , Micius satellite, MIT Technology Review, , Teleportation achieved   

    From MIT Tech Review: “First Object Teleported from Earth to Orbit” 

    MIT Technology Review
    M.I.T Technology Review

    July 10, 2017
    No writer credit found

    Researchers in China have teleported a photon from the ground to a satellite orbiting more than 500 kilometers above.

    Last year, a Long March 2D rocket took off from the Jiuquan Satellite Launch Centre in the Gobi Desert carrying a satellite called Micius, named after an ancient Chinese philosopher who died in 391 B.C. The rocket placed Micius in a Sun-synchronous orbit so that it passes over the same point on Earth at the same time each day.

    Micius is a highly sensitive photon receiver that can detect the quantum states of single photons fired from the ground. That’s important because it should allow scientists to test the technological building blocks for various quantum feats such as entanglement, cryptography, and teleportation.

    2
    Micius satellite. https://www.fusecrunch.com/chinas-first-quantum-satellite.html

    Today, the Micius team announced the results of its first experiments. The team created the first satellite-to-ground quantum network, in the process smashing the record for the longest distance over which entanglement has been measured. And they’ve used this quantum network to teleport the first object from the ground to orbit.

    Teleportation has become a standard operation in quantum optics labs around the world. The technique relies on the strange phenomenon of entanglement. This occurs when two quantum objects, such as photons, form at the same instant and point in space and so share the same existence. In technical terms, they are described by the same wave function.

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    No image caption or credit.

    The curious thing about entanglement is that this shared existence continues even when the photons are separated by vast distances. So a measurement on one immediately influences the state of the other, regardless of the distance between them.

    Back in the 1990s, scientists realized they could use this link to transmit quantum information from one point in the universe to another. The idea is to “download” all the information associated with one photon in one place and transmit it over an entangled link to another photon in another place.

    This second photon then takes on the identity of the first. To all intents and purposes, it becomes the first photon. That’s the nature of teleportation and it has been performed many times in labs on Earth.

    Teleportation is a building block for a wide range of technologies. “Long-distance teleportation has been recognized as a fundamental element in protocols such as large-scale quantum networks and distributed quantum computation,” says the Chinese team.

    In theory, there should be no maximum distance over which this can be done. But entanglement is a fragile thing because photons interact with matter in the atmosphere or inside optical fibers, causing the entanglement to be lost.

    As a result, the distance over which scientists have measured entanglement or performed teleportation is severely limited. “Previous teleportation experiments between distant locations were limited to a distance on the order of 100 kilometers, due to photon loss in optical fibers or terrestrial free-space channels,” says the team.

    But Micius changes all that because it orbits at an altitude of 500 kilometers, and for most of this distance, any photons making the journey travel through a vacuum. To minimize the amount of atmosphere in the way, the Chinese team set up its ground station in Ngari in Tibet at an altitude of over 4,000 meters. So the distance from the ground to the satellite varies from 1,400 kilometers when it is near the horizon to 500 kilometers when it is overhead.

    To perform the experiment, the Chinese team created entangled pairs of photons on the ground at a rate of about 4,000 per second. They then beamed one of these photons to the satellite, which passed overhead every day at midnight. They kept the other photon on the ground.

    Finally, they measured the photons on the ground and in orbit to confirm that entanglement was taking place, and that they were able to teleport photons in this way. Over 32 days, they sent millions of photons and found positive results in 911 cases. “We report the first quantum teleportation of independent single-photon qubits from a ground observatory to a low Earth orbit satellite—through an up-link channel— with a distance up to 1400 km,” says the Chinese team.

    This is the first time that any object has been teleported from Earth to orbit, and it smashes the record for the longest distance for entanglement.

    That’s impressive work that sets the stage for much more ambitious goals in the future. “This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet,” says the team.

    It also shows China’s obvious dominance and lead in a field that, until recently, was led by Europe and the U.S.—Micius would surely have been impressed. But an important question now is how the West will respond.

    See the full article here .

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  • richardmitnick 2:17 pm on July 11, 2017 Permalink | Reply
    Tags: Amygdala, Kay Tye, MIT Technology Review, Neurons, , Picower Institute for Learning and Memory,   

    From MIT Tech Review: Women in STEM – “How the Brain Seeks Pleasure and Avoids Pain” Kay Tye 

    MIT Technology Review
    M.I.T Technology Review

    June 27, 2017
    Amanda Schaffer

    1
    Neuroscientist Kay Tye

    As a child, Kay Tye was immersed in a life of science. “I grew up in my mom’s lab,” she says. At the age of five or six, she earned 25 cents a box for “restocking” bulk-ordered pipette tips into boxes for sterilization as her mother, an acclaimed biochemist at Cornell University, probed the genetics of yeast. (Tye’s father is a theoretical physicist known for his work on cosmic inflation and superstring theory.)

    Today, Tye runs her own neuroscience lab at MIT. Under large black lights reminiscent of a fashion shoot, she and her team at the Picower Institute for Learning and Memory can observe how mice behave when particular brain circuits are turned on or off. Nearby, they can record the mice’s neural activity as the animals move toward a particular stimulus, like sugar water, or away, if they’re crossing a floor that delivers mild electric shocks. Elsewhere, they create brain slices to test in vitro, since these samples retain their physiological activity, even outside the body, for up to eight hours.

    Tye has been at the forefront of efforts to pinpoint the sources of anxiety and other emotions in the brain by analyzing how groups of neurons work together in circuits to process information. In particular, her work has contributed to a profound shift in researchers’ understanding of the amygdala, a brain area that has been thought of as central to fear responses: she has found that signaling in the amygdala can in fact reduce anxiety as well as increase it. To gain such insights, she has also made crucial advances in a technique, called optogenetics, that allows researchers to activate or suppress particular neural circuits in lab animals using light. Optogenetics was developed by Stanford neuroscientist and psychiatrist Karl ­Deisseroth, and it represented a breakthrough in efforts to determine the role of specific parts of the brain. While Tye was working in his laboratory as a postdoc, she demonstrated, for the first time, that it was possible to pinpoint and control specific groups of neurons that were sending signals to specific target neurons.

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    No image caption or credit.

    This fine-grained approach is important because drugs that treat conditions like anxiety currently do not target specific circuits, let alone individual neurons; rather, they operate throughout the brain, which often leads to undesirable side effects. Tye’s research may eventually help open the door to drugs that affect only specific neural circuits, reducing anxiety with fewer side effects.

    Such work has earned formal accolades, including a Presidential Early Career Award for Scientists and Engineers from President Obama, a Freedman Prize for neuroscience, and a TR35 award, recognizing outstanding researchers under the age of 35. Tye has also won high praise from others in her field who admire the creative breadth of her ambition. “She’s not afraid to ask the most fundamental questions, the ones most other scientists shy away from,” says Sheena Josselyn of the University of Toronto and the Hospital for Sick Children Research Institute.

    The questions she takes on involve emotions and phenomena that loom large in human experience, such as reward-seeking, loneliness, and compulsive overeating. Her goal is to understand their neural basis—to bridge the gap between brain, as understood by neuroscientists, and the mind, as conceived more expansively by psychiatrists, psychologists, and other students of human behavior.

    Would-be novelist

    Though it might seem as if Tye was born to be a scientist, she says her choice of career was anything but inevitable. In high school, she was ambivalent about science and gravitated instead toward writing; she wrote plays, short stories, and poetry. “In my mind, I was going to be a novelist,” she recalls.

    Still, while applying to college, she included MIT on her list, partly to humor her parents, Bik-Kwoon Tye and Henry Tye, both of whom had earned PhDs there in 1974. And when she received an acceptance letter, her father found it hard to disguise his feelings as his eyes welled with tears. “I’d never in my life seen my dad cry,” she says. She decided that she ought to give scientific learning a more dedicated try. She also convinced herself (with parental encouragement) that focusing on the natural world would give her more to write about down the road.

    As a freshman at MIT, Tye joined the lab of Suzanne Corkin, who was working with H.M., one of the most famous patients in the history of neuroscience. H.M., whose name was revealed to be Henry Molaison upon his death in 2008, suffered from profound amnesia after a lobotomy to treat seizures; studying his condition allowed researchers to probe the neural underpinnings of memory. One of Tye’s roles in the group was to make H.M. a peanut butter and jelly sandwich for lunch. He would eat it and then, moments later, with crumbs still on his face, ask, “Did we have lunch yet?”

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    Researchers troubleshoot behavioral boxes in which mice learn to form positive and negative associations with sounds. No image credit.

    “It made me appreciate that these basic functions, like memory, that are so key to who we are have biological substrates in the brain,” she says. Neuroscience can be intimidating and filled with jargon, she adds. But the experience with H.M., along with an inspiring introductory psychology class taught by Steven Pinker, “made it seem worth it to slog through the all-nighters” to understand the biological mechanisms behind psychological constructs.

    Still, after graduation, Tye wanted to make sure she was “looking around,” thinking about who she was and who she wanted to be. So she spent a year backpacking in Australia, where she worked on a farm, lived in a yoga ashram, taught yoga, camped out on the beach, and worked on a novel. She found that writing was “hard and lonely.” She enjoyed teaching yoga but didn’t see it as a satisfying career path.

    “I came out of that year surprisingly ready to go to grad school,” she says. Diving back into the academic world, she initially struggled to find a lab that would accept her and almost dropped out after her first year. But she found a mentor in Patricia Janak, who became her advisor, and earned a PhD in neuroscience at the University of California, San Francisco, in 2008.

    A surprise in the amygdala

    In 2009, Tye joined Deisseroth’s lab at Stanford. Deisseroth had already developed optogenetics, which gave researchers a much more precise way to identify the contributions of individual neurons within a circuit. Along with others in the lab, Tye used optogenetics to probe the connection between two parts of the amygdala, an almond-shaped region that is crucial to anxiety and fear. She first identified neurons in one area (known as the basolateral amygdala) that formed connections to neurons in another amygdalar area (known as the central nucleus) by sending out projections of nerve fibers. When she stimulated those basolateral amygdala neurons, she was able to reduce anxiety in mice. That is, she could cause the animals to spend more time in open spaces and less time cowering to the side. This was surprising, because when researchers stimulated the amygdala as a whole, the mice’s behavior grew more anxious.

    At first, everyone asked, “Are you sure you’re using the tool right? What’s going on?” she recalls. But after meticulous validation, in 2011, Tye and the group published their results in Nature, showing that some circuitry within the amygdala helps to calm animals down. This paper also represented a breakthrough in optogenetic technique. For the first time, researchers were able to zero in on and manipulate a specific part of a brain circuit: particular groups of neurons communicating with known target neurons. The technique, known as optogenetic projection-specific manipulation, is now considered one of the key tools of neuroscience.

    In 2012, Tye came to MIT as an assistant professor of brain and cognitive sciences at the Picower, continuing her work on anxiety. While setting up her lab, she targeted neurons within the amygdala that seemed to have the opposite effect on mouse anxiety, causing it to increase. These brain cells are also located in the basolateral amygdala, but they send projections to a nearby region known as the ventral hippocampus. When Tye stimulated this circuit using optogenetics, the mice avoided open spaces, apparently suffering from anxiety. (When she inhibited the connections from forming, the animals hung out in the open again, their anxiety seemingly alleviated.) Tye proposed that neighboring neurons in the amygdala can have opposite effects on animals’ behavior, depending on the targets to which they send signals.

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    Tye lab grad students Chris Leppla and Caitlin Vander Weele and postdocs Praneeth Namburi and Stephen Allsop. No image credit.

    Threats and rewards

    At the time, most researchers studying the amygdala still tended to focus mainly on its role in fear. Yet Tye suspected that activity in this part of the brain might encode a stimulus as either rewarding or threatening, good or bad, helping individuals decide how to respond. “There are many stimuli we encounter in our daily lives that are ambiguous,” says Conor ­Liston of the Brain and Mind Research Institute at Weill Cornell. “A social interaction, for example, can be either threatening or rewarding, and we need brain circuits devoted to differentiating which is which.”

    By looking at the relative strength of the currents passing through two glutamate receptors known to indicate synaptic strength, Tye discovered that different neural connections in mice were reinforced depending on whether a particular stimulus was linked to a reward or a threat. When mice learned to associate a sound with a treat of sugar, she found stronger synaptic input to the neurons in the basolateral amygdala that were sending information to the nucleus accumbens, which is part of the brain’s reward circuitry. On the other hand, when mice learned to associate the sound with mild electric shocks to their feet, input signals grew stronger in circuits leading from the basolateral amygdala to the centromedial amygdala, which is involved in pain and fear. In addition, she demonstrated a trade-off: when one of these circuits grew more active, the other grew less so. In other words, she had found how the brain encodes information that allows mice to differentiate between stimuli that are rewarding and those that are potentially harmful. The results were published in Nature in 2015.

    In recent work, Tye also probed the circuitry involved in making split-second decisions when both threatening and rewarding cues are present at the same time. She and her team focused this time on connections between the amygdala and the prefrontal cortex, an area responsible for higher-order thinking. (Specifically, they examined interactions between the basolateral amygdala and the prelimbic medial prefrontal cortex.) Using optogenetics and other techniques, they showed that this circuitry was active when the animals were simultaneously exposed to a potential sugar treat and a potential electric shock and had to make a decision about how to behave. Her results, which appeared in April in Nature Neuroscience, help illuminate how animals figure out what to do in the face of complex and sometimes contradictory cues.

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    Grad student Caitlin Vander Weele examines magnified images of brain slices to verify that a calcium sensor is targeting a specific type of neuron. No image credit.

    Cravings and compulsions

    As a graduate student, Tye had worked with researchers focused on addiction, but she was more interested in natural rewards, like sugar, than in substances that are regularly abused. In 2012, New York City mayor Michael Bloomberg announced a plan to limit the portion size of sodas sold in movie theaters, stadiums, and fast-food restaurants. Tye found herself wondering what exactly, at a brain level, causes people to crave sugary treats, above and beyond the normal drive to satisfy hunger.

    So she delved into the neural circuitry. In a paper published in 2015 in Cell, she and her team focused on neurons in the lateral hypothalamus (LH), a brain area involved in drives like hunger, and studied their projections into another region, called the ventral tegmental area (VTA), known to play a role in both motivation and addiction. Using optogenetics, she and her team showed that turning on specific LH-VTA connections caused the mice to gorge on sugar, while turning them off reduced the compulsive overeating.

    On her desktop, Tye loads a video demonstration featuring a mouse with a cable for light transmission attached to its brain. The video shows the mouse moving around, casually at first. Then, when the laser light is turned on to activate specific neurons in the LH-VTA circuit, the animal becomes frantic, running and licking the floor. Soon after, it brings its empty paws up to its mouth and does a pantomime of tasting and nibbling. “It engages in this complicated motor sequence and pretends to eat, which is crazy because there’s no food,” says Tye. In other words, turning the circuit on causes the animal to behave compulsively. Turning it off has the opposite effect.

    Crucially, though, while switching off this circuit prevents compulsive behavior, it does not affect normal eating. That is, it is possible to define a brain-based difference between at least some healthy and unhealthy drives to eat. This suggests that it might be possible to develop targeted drugs or even some form of biofeedback that might someday help people reduce unhealthy cravings without blocking ordinary hunger.

    Another recent finding, about loneliness, arose serendipitously from a project that postdoc Gillian Matthews had begun as a graduate student at Imperial College London with Mark Ungless. ­Matthews noticed that mice that had been isolated for 24 hours during experiments displayed stronger neural signaling in the brain’s dorsal raphe nucleus, which participates in reward signaling—and actively sought out the company of other mice. After she moved to Tye’s lab at MIT, Matthews and Tye developed the theory that the animals were craving interaction. In further experiments, they used optogenetics to turn off the signaling pathway in the dorsal raphe nucleus. Mice subjected to this treatment did not seem to seek out additional social interaction following time by themselves.

    Ultimately, Tye hopes that she and her team can speak to fundamental human questions, like why some people prefer to spend more time alone while others crave greater social contact.

    A lab without drama

    Though Tye’s lab is interested in the origins of phenomena like fear and compulsion, it is notable for its own lack of tension and conflict. Stephen Allsop, a postdoc who has worked with her for five years (several of which were spent as a graduate student), says that she stresses close collaboration among team members and oversees an upbeat, supportive culture: “It’s amazing how little drama we have in this lab.”

    “Along with scientific integrity, I make the positive, collaborative, open culture of my research group—and the happiness of the individuals within it—my top priority,” says Tye. “Scientific excellence is a close second.” Strong relationships with professors and mentors are part of the draw of science, she adds.

    Indeed, she says, they are second only to the bonds between parents and children. In 2013, Tye and her husband, Jim Wagner, a software developer, had a daughter, Keeva, who has already accompanied her to conferences around the world. Their son, Jet, was born last year. And the children have found a place in her lab, much as she found a niche in her mother’s (though they have yet to earn paid positions). As she told Nature when Keeva was still an infant: “If my daughter all of a sudden needs to be picked up, I bring her to my lab meeting or meet with people while I bounce her. If she has a total meltdown, then sometimes I have to bail and follow up later.”

    But while she may be easygoing as a parent and a lab leader, Tye finds plenty of drama in neuroscience itself, and she keeps returning to its central questions because they are so enticing. Though she says she reads fewer novels now than she used to, she still seems compelled by the kinds of mysteries a writer might probe: Why does a hero set out on a journey? Why does the chatter in his or her head go awry and lead to gloomy soliloquizing or anxious self-sabotage? Like a novelist, she exhibits tremendous creative breadth. “There is something special about science,” she says. “Your new work is based on what you did previously. And if you’re lucky, you can help shape the future.”

    See the full article here .

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  • richardmitnick 4:02 pm on May 5, 2017 Permalink | Reply
    Tags: , Astrophysicists Turn GPS Satellite Constellation into Giant Dark Matter Detector, , , , , MIT Technology Review   

    From MIT Tech Review: “Astrophysicists Turn GPS Satellite Constellation into Giant Dark Matter Detector” 

    MIT Technology Review
    M.I.T. Technology Review

    May 4, 2017
    Emerging Technology from the arXiv
    If Earth is sweeping through an ocean of dark matter, the effects should be visible in clock data from GPS satellites.

    1

    The Global Positioning System consists of 31 Earth-orbiting satellites, each carrying an atomic clock that sends a highly accurate timing signal to the ground. Anybody with an appropriate receiver can work out their position to within a few meters by comparing the arrival time of signals from three or more satellites.

    And this system can easily be improved. The accuracy of GPS signals can be made much higher by combining the signals with ones produced on the ground. Geophysicists, for example, use this technique to determine the position of ground stations to within a few millimeters. In this way, they can measure the tiny movements of entire continents.

    This is an impressive endeavor. Geophysicists routinely measure the difference between GPS signals and clocks on the ground with an accuracy of less than 0.1 nanoseconds. They also archive this data providing a detailed record of how GPS signals have changed over time. This archival storage opens the possibility of using the data for other exotic studies.

    Today Benjamin Roberts at the University of Nevada and a few pals say they have used this data to find out whether GPS satellites may have been influenced by dark matter, the mysterious invisible stuff that astrophysicists think fills our galaxy. In effect, these guys have turned the Global Positioning System into an astrophysical observatory of truly planetary proportion.

    The theory behind dark matter is based in observations of the way galaxies rotate. This spinning motion is so fast that it should send stars flying off into extra-galactic space.

    But this doesn’t happen. Instead, a mysterious force must somehow hold the stars in place. The theory is that this force is gravity generated by invisible stuff that doesn’t show up in astronomical observations. In other words, dark matter.

    If this theory is correct, dark matter should fill our galaxy, too, and as the sun makes its stately orbit round the galactic center, Earth should plough through a great ocean of dark matter.

    There’s no obvious sign of this stuff, which makes physicists think it must interact very weakly with ordinary visible matter. But they hypothesize that if dark matter exists in small atomic-sized lumps, it might occasionally hit atomic nuclei head on, thereby transferring their energy to visible matter.

    That’s why astrophysicists have built giant observatories in underground mines to look for the tell-tale energy released in these collisions. So far, they’ve seen nothing. Or at least, there is no consensus that anybody has seen evidence of dark matter. So other ways to look for dark matter are desperately needed.

    Enter Roberts and co. They start with a different vision of what dark matter may consist of. Instead of small particles, another option is that dark matter may take the form of topological defects in space-time left over from the Big Bang. These would be glitches in the fabric of the universe, like domain walls, that bend space-time in their vicinity.

    Should the Earth pass through such a defect, it would change the local gravitational field just slightly over a period of an hour or so.

    But how to detect such a change in the local field? To Roberts and co, the answer is clear. According to relativity, any change in gravity also changes the rate at which a clock ticks. That’s why orbiting clocks run a little bit slower than those on the surface.

    If the Earth has passed through any topological defects in the recent past, the clock data from GPS satellites would have recorded this event. So by searching through geophysicists’ archived records of GPS clock timings, it ought to be possible to see such events.

    That’s the theory. In practice, this work is a little more complicated because GPS timing signals are also influenced by other factors such as atmospheric conditions, random variations, and other things. All these need to be taken into account.

    But a key signature of a topological defect is that its influence should sweep through the fleet of satellites as the Earth passes through it. So any other kinds of local timing fluctuation can be ruled out.

    Roberts and co study the data over the last 16 years, and their results make for interesting reading. These guys say they have found no sign that Earth has passed through a topological defect in that time. “We find no evidence for dark matter clumps in the form of domain walls,” they say.

    Of course, that doesn’t rule out the existence of dark matter or even that dark matter exists in this form. But it does place strong limits on how common topological defects can be and how strong their influence is.

    Until now, the limits have been set using observations of the cosmic microwave background radiation, which should reveal topological defects, albeit at low resolution. The work of Roberts and co improves these limits by five orders of magnitude.

    And better data should be available soon. The best clocks in Earth laboratories are orders of magnitude more accurate than the atomic clocks on board GPS satellites. So a network of clocks on Earth should act as an even more sensitive observatory for topological defects. These clocks are only just becoming linked together in networks, so the data from them should be available in the coming years.

    This greater sensitivity should allow physicists to look for other types of dark matter, which may take the form of solitons or Q-balls, for example.

    All this is part of a fascinating process of evolution. The technology behind the GPS system can be traced directly back to the first attempts to track the Sputnik spacecraft after the Soviets launched it in 1957. Physicists soon realized they could determine its location by measuring the radio signals it generated at different places.

    It wasn’t long before they turned this idea on its head. Given the known location of a satellite, is it possible to determine your location on Earth using the signals it broadcasts? The GPS constellation is a direct descendant of that train of thought.

    Those physicists would surely be amazed to know that the technology they developed is also now being used as a planetary-sized astrophysical observatory.

    Ref: arxiv.org/abs/1704.06844: GPS as a Dark-Matter Detector: Orders-of-Magnitude Improvement on Couplings of Clumpy Dark Matter to Atomic Clocks

    See the full article here .

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  • richardmitnick 3:44 pm on February 23, 2017 Permalink | Reply
    Tags: Magnetic resonance imaging, MIT Technology Review, University of Melbourne   

    From MIT Tech Review: “This Microscope Reveals Human Biochemistry at Previously Unimaginable Scales” 

    MIT Technology Review
    M.I.T Technology Review

    February 23, 2017

    1

    Magnetic resonance imaging is one of the miracles of modern science. It produces noninvasive 3-D images of the body using harmless magnetic fields and radio waves. And with a few additional tricks, it can also reveal details of the biochemical makeup of tissue.

    1
    Atomic-scale MRI holds promise for new drug discovery | The Melbourne Newsroom

    That biochemical trick is called magnetic resonance spectroscopy, and it is a powerful tool for physicians and researchers studying the biochemistry of the body, including metabolic changes in tumors in the brain and in muscles.

    But this technique is not perfect. The resolution of magnetic resonance spectroscopy is limited to length scales of about 10 micrometers. And there is a world of chemical and biological activity at smaller scales that scientists simply cannot access in this way.

    So physicians and researchers would dearly love to have a magnetic resonance microscope that can study body tissue and the biochemical reactions within it at much smaller scales.

    Today, David Simpson and pals at the University of Melbourne in Australia say they have built a magnetic resonance microscope with a resolution of just 300 nanometers that can study biochemical reactions on previously unimaginable scales. Their key breakthrough is an exotic diamond sensor that creates magnetic resonance images in a similar way to a light sensitive CCD chip in a camera.

    Magnetic resonance imaging works by placing a sample in a magnetic field so powerful that the atomic nuclei all become aligned; in other words, they all spin the same way. When these nuclei are zapped with radio waves, the nuclei become excited and then emit radio waves as they relax. By studying the pattern of re-emitted radio waves, it is possible to work out where they have come from and so build up a picture of the sample.

    The signals also reveal how the atoms are bonded to each other and the biochemical processes at work. But the resolution of this technique is limited by how closely the radio receiver can get to the sample.

    Enter Simpson and co, who have built an entirely new kind of magnetic resonance sensor out of diamond film. The secret sauce in this sensor is an array of nitrogen atoms that have been embedded in a diamond film at a depth of about seven nanometers and about 10 nanometers apart.

    Nitrogen atoms are useful because when embedded in diamond, they can be made to fluoresce. And when in a magnetic field, the color they produce is highly sensitive to the spin of atoms and electrons nearby or, in other words, to the local biochemical environment.

    So in the new machine, Simpson and co place their sample on top of the diamond sensor, in a powerful magnetic field and zap it with radio waves. Any changes in the state of nearby nuclei causes the nitrogen array to fluoresce in various colors. And the array of nitrogen atoms produces a kind of image, just like a light sensitive CCD chip. All Simpson and co do is monitor this fireworks display to see what’s going on.

    To put the new technique through its paces, Simpson and co study the behavior of hexaaqua copper(2+) complexes in aqueous solution. Hexaaqua copper is present in many enzymes which use it to incorporate copper in metalloproteins. However, the distribution of copper during this process, and the role it plays in cell signaling, is poorly understood because it is impossible to visualize in vivo.

    Simpson and co show how this can now be done using their new technique, which they call quantum magnetic resonance microscopy. They show how their new sensor can reveal the spatial distribution of copper 2+ ions in volumes of just a few attoLitres and at high resolution. “We demonstrate imaging resolution at the diffraction limit (~300 nm) with spin sensitivities in the zeptomol (10‐21) range,” say Simpson and co. They also show how the technique reveals the redox reactions that the ions undergo. And they do all this at room temperature.

    That’s impressive work that has important implications for the future study of biochemistry. “The work demonstrates that quantum sensing systems can accommodate the fluctuating Brownian environment encountered in ‘real’ chemical systems and the inherent fluctuations in the spin environment of ions undergoing ligand rearrangement,” says Simpson and co.

    That makes it a powerful new tool that could change the way we understand biological processes. Simpson and co are optimistic about its potential. “Quantum magnetic resonance microscopy is ideal for probing fundamental nanoscale biochemistry such as binding events on cell membranes and the intra‐cellular transition metal concentration in the periplasm of prokaryotic cells.”

    Ref: arxiv.org/abs/1702.04418: Quantum Magnetic Resonance Microscopy

    See the full article here .

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  • richardmitnick 12:48 pm on January 8, 2017 Permalink | Reply
    Tags: A test that will detect all of the major cancer types, , , , MIT Technology Review   

    From MIT Tech Review: “Liquid Biopsies Are About to Get a Billion Dollar Boost’ 

    MIT Technology Review
    M.I.T Technology Review

    January 6, 2017
    Michael Reilly

    A billion dollars sounds like a lot of money. But when your ambitions are as big as the cancer-detection startup Grail Bio’s are, it might not be enough.

    As CEO and ex-Googler Jeff Huber puts it, Grail’s aim is to create “a test that will detect all of the major cancer types.” Already the recipient of $100 million in funding from DNA sequencing company Illumina and a series of tech luminaries, Grail believes that adding another zero to its cash balance will put its lofty goals within reach. The company announced Thursday that it plans to raise $1 billion, has “indications of interest” from investors, and would move quickly to secure the hefty cash infusion.

    Whether Grail succeeds turns on the company’s ability to dramatically expand an emerging technology known as the liquid biopsy. It works by sequencing DNA from someone’s blood and looking for tell-tale fragments that indicate the presence of cancer. Dennis Lo, a doctor in Hong Kong, was among the first to show the technique’s promise. He’d previously used it to detect fetal DNA in a mother’s bloodstream. That led to a much safer form of screening for Down’s syndrome that is now in wide use.

    Lo has experimented with liquid biopsy as a way to catch liver and nasopharyngeal cancers, with some encouraging results. But he urged caution in assuming the technique could be translated to all cancers.

    Grail, which was spun out of Illumina about a year ago, has launched its first trials to see whether liquid biopsies can spot cancers earlier and more reliably than other screening tests.

    For his part, Huber seems to understand that he’s got a mountain to climb. After losing his wife to colorectal cancer, Grail’s mission is deeply personal. He acknowledges that detecting cancer DNA may be difficult, because the disease mutates rapidly as it advances, and varies immensely from one type to another. He says his company will rely on sequencing the DNA of tens of thousands of subjects to build a library of cancer DNA that computers can then decipher.

    Beyond the high-minded talk of turning the tide in the war against cancer, though, is a more cynical reading of the situation. As a unit within Illumina, Grail was an expensive, long-shot bet to create a new market for its gene sequencing machines. As a separate, now cash-rich company, Grail figures to become one of Illumina’s biggest customers. And venture capital will foot the bill, whether or not the experiment works.

    See the full article here .

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  • richardmitnick 3:16 pm on December 23, 2016 Permalink | Reply
    Tags: and Google, , , Intel and Competitors IBM, , MIT Technology Review,   

    From MIT Tech Review: “Intel Bets It Can Turn Everyday Silicon into Quantum Computing’s Wonder Material” 

    MIT Technology Review
    MIT Technology Review

    December 21, 2016
    Tom Simonite

    The world’s largest chip company sees a novel path toward computers of immense power.

    1
    Researchers at TU Delft in the Netherlands use equipment like this to test quantum computing devices at supercool temperatures, in a collaboration with chip maker Intel. No image credit.

    Sometimes the solution to a problem is staring you in the face all along. Chip maker Intel is betting that will be true in the race to build quantum computers—machines that should offer immense processing power by exploiting the oddities of quantum mechanics.

    Competitors IBM, Microsoft, and Google are all developing quantum components that are different from the ones crunching data in today’s computers. But Intel is trying to adapt the workhorse of existing computers, the silicon transistor, for the task.

    Intel has a team of quantum hardware engineers in Portland, Oregon, who collaborate with researchers in the Netherlands, at TU Delft’s QuTech quantum research institute, under a $50 million grant established last year. Earlier this month Intel’s group reported that they can now layer the ultra-pure silicon needed for a quantum computer onto the standard wafers used in chip factories.

    This strategy makes Intel an outlier among industry and academic groups working on qubits, as the basic components needed for quantum computers are known. Other companies can run code on prototype chips with several qubits made from superconducting circuits (see Google’s Quantum Dream Machine). No one has yet advanced silicon qubits that far.

    A quantum computer would need to have thousands or millions of qubits to be broadly useful, though. And Jim Clarke, who leads Intel’s project as director of quantum hardware, argues that silicon qubits are more likely to get to that point (although Intel is also doing some research on superconducting qubits). One thing in silicon’s favor, he says: the expertise and equipment used to make conventional chips with billions of identical transistors should allow work on perfecting and scaling up silicon qubits to progress quickly.

    Intel’s silicon qubits represent data in a quantum property called the “spin” of a single electron trapped inside a modified version of the transistors in its existing commercial chips. “The hope is that if we make the best transistors, then with a few material and design changes we can make the best qubits,” says Clarke.

    Another reason to work on silicon qubits is that they should be more reliable than the superconducting equivalents. Still, all qubits are error prone because they work on data using very weak quantum effects (see Google Researchers Make Quantum Components More Reliable).

    The new process that helps Intel experiment with silicon qubits on standard chip wafers, developed with the materials companies Urenco and Air Liquide, should help speed up its research, says Andrew Dzurak, who works on silicon qubits at the University of New South Wales in Australia. “To get to hundreds of thousands of qubits, we will need incredible engineering reliability, and that is the hallmark of the semiconductor industry,” he says.

    Companies developing superconducting qubits also make them using existing chip fabrication methods. But the resulting devices are larger than transistors, and there is no template for how to manufacture and package them up in large numbers, says Dzurak.

    Chad Rigetti, founder and CEO of Rigetti Computing, a startup working on superconducting qubits similar to those Google and IBM are developing, agrees that this presents a challenge. But he argues that his chosen technology’s head start will afford ample time and resources to tackle the problem.

    Google and Rigetti have both said that in just a few years they could build a quantum chip with tens or hundreds of qubits that dramatically outperforms conventional computers on certain problems, even doing useful work on problems in chemistry or machine learning.

    No sciencde papers cited.

    See the full article here .

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  • richardmitnick 3:38 pm on December 7, 2016 Permalink | Reply
    Tags: , , , MIT Technology Review   

    From MIT Tech Review: “Personalized Cancer Vaccine Prevents Leukemia Relapse in Patients” 

    MIT Technology Review
    M.I.T Technology Review

    December 7, 2016
    Emily Mullin

    Shortly after Ernest Levy of Cooperstown, New York, returned from a trip to South Africa with his son for the 2010 World Cup, he was diagnosed with acute myeloid leukemia. The prognosis didn’t look good for Levy, now 76. Just over a quarter of adult patients survive five years after developing the disease, a type of cancer that affects bone marrow.

    Levy joined a clinical trial led by the Beth Israel Deaconess Medical Center, a teaching hospital of Harvard Medical School in Boston, testing a cancer vaccine for acute myeloid leukemia. After an initial round of chemotherapy, he and the other trial participants received the experimental vaccine, a type of immunotherapy intended to “reëducate” the immune cells to see cancer cells as foreign and attack them, explains David Avigan, chief of Hematological Malignancies and director of the Cancer Vaccine Program at Beth Israel.

    Now results from the trial suggest that the vaccine was able to stimulate powerful immune responses against cancer cells and protect a majority of patients from relapse—including Levy. Out of 17 patients with an average age of 63 who received the vaccine, 12 are still in remission four years or more after receiving the vaccine, Avigan and his co-authors at the Dana-Farber Cancer Institute report. The researchers found expanded levels of immune cells that recognize acute myeloid leukemia cells after vaccination. The results appear today in the journal Science Translational Medicine.

    Acute myeloid leukemia is typically treated with a combination of chemotherapies, but the cancer often relapses after initial treatment, with older patients having a higher chance of relapse.

    Therapeutic cancer vaccines are designed to work by activating immune cells called T cells and directing them to recognize and act against cancer cells, or by spurring the production of antibodies that bind to certain molecules on the surface of cancer cells. But producing effective therapeutic vaccines has proved challenging, with many of these vaccines either failing outright or showing only marginal increases in survival rates in clinical trials.

    Avigan and his colleagues created a personalized vaccine by taking leukemia cells from patients and then freezing them for preservation while they received a traditional chemotherapy. Then scientists thawed the cancer cells and combined them with dendritic cells, immune cells that unleash tumor-fighting T cells. The vaccine took about 10 days to manufacture and another three to four weeks before it was ready for administration.

    Many cancer vaccine strategies have homed in on a single target, or antigen. When the antigen is introduced in the body via injection, it causes an immune response. The body begins to produce T cells that recognize and attack the same antigen on the surface of cancer cells. The vaccine Avigan and his team created uses a mixture of cells that contain many antigens in an attempt to generate a more potent approach.

    Though the number of patients in the trial was small, Avigan says, “this was enough of a provocative finding” that the researchers will be expanding the trial to include more patients. At the same time, the personalized vaccine approach is already being tested in other types of cancers.

    See the full article here .

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  • richardmitnick 2:42 pm on August 18, 2016 Permalink | Reply
    Tags: , , MIT Technology Review,   

    From MIT Tech Review: “New Brain-Mapping Technique Captures Every Connection Between Neurons” 

    MIT Technology Review
    M.I.T Technology Review

    August 18, 2016
    Ryan Cross

    The human brain is among the universe’s greatest remaining uncharted territories. And as with any mysterious land, the secret to understanding it begins with a good map.

    Neuroscientists have now taken a huge step toward the goal of mapping the connections between neurons in the brain using bits of genetic material to bar-code each individual brain cell. The technique, called MAP-seq, could help researchers study disorders like autism and schizophrenia in unprecedented detail.

    “We’ve got the basis for a whole new technology with a gazillion applications,” says Anthony Zador, a neuroscientist at Cold Spring Harbor Laboratory who came up with the technique.

    Current methods for mapping neuronal connections, known as the brain’s connectome, commonly rely on fluorescent proteins and microscopes to visualize cells, but they are laborious and have difficultly following the connections of many neurons at once.

    MAP-seq works by first creating a library of viruses that contain randomized RNA sequences. This mixture is then injected into the brain, and approximately one virus enters each neuron in the injection area, granting each cell a unique RNA bar code. The brain is then sliced and diced into orderly sections for processing. A DNA sequencer reads the RNA bar codes, and researchers create a connectivity matrix that displays how individual neurons connect to other regions of the brain.

    The newly published study, which appears Thursday in the journal Neuron, follows the sprawling outbound connections from 1,000 mouse neurons in a brain region called the locus coeruleus to show that the technique works. But Zador says the results actually reconcile previously conflicting findings about how those neurons connect across the brain.

    Justus Kebschull, who worked with Zador in developing MAP-seq, says the technique is getting better. “We’re now mapping out 100,000 cells at a time, in one week, in one experiment,” he says. “That was previously only possible if you put a ton of work in.”

    Both autism and schizophrenia are viewed as disorders that may arise from dysfunctional brain connectivity. There are perhaps hundreds of genetic mutations that may slightly alter the brain’s wiring as it develops. “We are looking at mouse models where something is mucked up. And now that the method is so fast, we can look at many mouse models,” Kebschull says. By comparing the brain circuitry in mice with different candidate genes for autism, researchers expect, they’ll get new insight into the condition.

    “I think it is a great method that has a lot of room to grow,” says Je Hyuk Lee, a molecular biologist at Cold Spring Harbor Laboratory, who was not part of the MAP-seq study. Although other groups have used similar bar-coding to study individual differences between cells, no one knew if the bar codes would be able to travel along the neuronal connections across the brain. “That had been conjectured but never shown, especially not at this scale,” Lee says.

    Zador says that as of now, his lab is the only one bar-coding the brain, but he hopes others will start using MAP-seq to chart the brain’s circuitry. “Because the cost of sequencing is continuing to plummet, we can envision doing this quickly and cheaply,” he said. It may not be long, then, before a complete map of the brain is ready for its first explorer to use.

    See the full article here .

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  • richardmitnick 10:51 am on June 11, 2016 Permalink | Reply
    Tags: , Genetic replacement therapy, MIT Technology Review, Strimvelis   

    From MIT Tech Review: “Gene Therapy’s First Out-and-Out Cure Is Here” 

    MIT Technology Review
    M.I.T Technology Review

    May 6, 2016
    Antonio Regalado

    1
    An artist’s illustration of gene therapy shows a retrovirus harboring a correct copy of a human gene. No image credit

    A treatment now pending approval in Europe will be the first commercial gene therapy to provide an outright cure for a deadly disease.

    The treatment is a landmark for gene-replacement technology, an idea that’s struggled for three decades to prove itself safe and practical.

    Called Strimvelis, and owned by drug giant GlaxoSmithKline, the treatment is for severe combined immune deficiency, a rare disease that leaves newborns with almost no defense against viruses, bacteria, or fungi and is sometimes called “bubble boy” disease after an American child whose short life inside a protective plastic shield was described in a 1976 movie.

    The treatment is different from any that’s come before because it appears to be an outright cure carried out through a genetic repair. The therapy was tested on 18 children, the first of them 15 years ago. All are still alive.

    “I would be hesitant to call it a cure, although there’s no reason to think it won’t last,” says Sven Kili, the executive who heads gene-therapy development at GSK.

    The British company licensed the treatment in 2010 from the San Raffaele Telethon Institute for Gene Therapy, in Milan, Italy, where it was developed and first tested on children.

    On April 1, European advisors recommended that Strimvelis be allowed on the market. If, as expected, GSK wins formal authorization, it can start selling the drug in 27 European countries. GSK plans to seek U.S. marketing approval next year.

    GSK is the first large drug company to seek to market a gene therapy to treat any genetic disease. If successful, the therapeutic could signal a disruptive new phase in medicine in which one-time gene fixes replace trips to the pharmacy or lifelong dependence on medication.

    “The idea that you don’t have to worry about it and can be normal is extremely exciting for people,” says Marcia Boyle, founder and president of the Immune Deficiency Foundation, whose son was born with a different immune disorder, one of more than 200 known to exist. “I am a little guarded on gene therapy because we were all excited a long time ago, and it was not as easy to fool Mother Nature as people had hoped.”

    Today, several hundred gene therapies are in development, and many aspire to be out-and-out cures for one of about 5,000 rare diseases caused by errors in a single gene.

    Children who lack correct copies of a gene called adenosine deaminase begin to get life-threatening infections days after birth. The current treatment for this immune deficiency, known as ADA-SCID, is a bone marrow transplant, which itself is sometimes fatal, or lifelong therapy using costly replacement enzymes that cost $5,000 a vial.

    Strimvelis uses a “repair and replace” strategy, so called because doctors first remove stem cells from a patient’s bone marrow then soak them with viruses to transfer a correct copy of the ADA gene.

    “What we are talking about is ex vivo gene therapy—you pull out the cells, correct them in test tube, and put the cells back,” says Maria-Grazia Roncarolo, a pediatrician and scientist at Stanford University who led the original Milan experiments. “If you want to fix a disease for life, you need to put the gene in the stem cells.”

    Some companies are trying to add corrected genes using direct injections into muscles or the eye. But the repair-and-replace strategy may have the larger impact. As soon as next year, companies like Novartis and Juno Therapeutics may seek approval for cancer treatments that also use a combination of gene and cell therapy to obliterate one type of leukemia.

    Overall, investment in gene therapy is booming. The Alliance for Regenerative Medicine says that globally, in 2015, public and private companies raised $10 billion, and about 70 treatments are in late-stage testing.

    GSK has never sold a product so drastically different from a bottle of pills. And because ADA-SCID is one of the rarest diseases on Earth, Strimvelis won’t be a blockbuster. GSK estimates there are only about 14 cases a year in Europe, and 12 in the U.S.

    Instead, the British company hopes to master gene-therapy technology, including virus manufacturing. “If we can first make products that change lives, then we can develop them into things that affect more people,” says Kili. “We believe gene therapy is an area of important future growth; we don’t want to rush or cut corners.”

    Markets will closely scrutinize how much GSK charges for Strimvelis. Kili says a final decision hasn’t been made. Another gene therapy, called Glybera, debuted with a $1 million price tag but is already considered a commercial flop. The dilemma is how to bill for a high-tech drug that people take only once.

    Kili says GSK’s price won’t be anywhere close to a million dollars, though it will be enough to meet a company policy of getting a 14 percent return on every dollar spent on R&D.

    The connection between immune deficiency and gene therapy isn’t new. In fact, the first attempt to correct genes in a living person occurred in 1990, also in a patient with ADA-SCID.

    By 2000, teams in London and France had cured some children of a closely related immune deficiency, X-linked SCID, the bubble boy disease. But some of those children developed leukemia after the viruses dropped their genetic payloads into the wrong part of the genome.

    In the U.S., the Food and Drug Administration quickly canceled 27 trials over safety concerns. “It was a major step back,” says Roncarolo, and probably a more serious red flag even than the death of a volunteer named Jesse Gelsinger in a U.S. trial in 1999, which also drew attention to gene therapy’s risks.

    The San Raffaele Telethon Institute for Gene Therapy presented its own results in ADA-SCID, which also affects girls, in 2002 in the journal Science. Like the French, they’d also apparently cured patients, and because of differences in their approach, they didn’t run the same cancer risk.

    GSK says it is moving toward commercializing several other gene therapies for rare disease developed by the Italian team, including treatments for metachromatic leukodystrophy, a rare but rapidly fatal birth defect, and for beta thalassemia.

    Kili says the general idea is to leapfrog from ultra-rare diseases to less rare ones, like beta thalassemia, hemophilia, and sickle cell disease. However, he doubts the technology will be used to treat common conditions such as arthritis or heart disease anytime soon. Those conditions are complex and aren’t caused by a defect in just one gene.

    “Honestly, as we stand at the moment, I don’t think gene therapy will address all the ills or ailments of humanity. We can address [single-gene] disease,” he says. “We are building a hammer that is not that big.”

    See the full article here .

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  • richardmitnick 8:19 am on June 10, 2016 Permalink | Reply
    Tags: A Power Plant in Iceland Deals with Carbon Dioxide by Turning It into Rock, , , MIT Technology Review   

    From MIT Tech Review: “A Power Plant in Iceland Deals with Carbon Dioxide by Turning It into Rock” 

    MIT Technology Review
    MIT Technology Review

    June 9, 2016
    Ryan Cross

    1
    Photograph by Juerg Matter

    The world has a carbon dioxide problem. And while there are lots of ideas on how to curtail the nearly 40 billion tons of the gas that humanity spews into the atmosphere annually, one has just gotten a boost: burying it.

    Since 2012, Reykjavík Energy’s CarbFix project in Iceland has been injecting carbon dioxide underground in a way that converts it into rock so that it can’t escape. This kind of carbon sequestration has been tried before, but as researchers working on the project report today in the journal Science, the process of mineralizing the carbon dioxide happens far more quickly than expected, confirming previous reports and brightening the prospects for scaling up this technology.

    Iceland’s volcanic landscape is replete with basalt. Injecting carbon dioxide and water deep underground allows the mixture to react with calcium, magnesium, and iron in the basalt, turning it into carbonate minerals like limestone.

    2
    Project leader Juerg Matter stands by the injection well during the CarbFix project’s initial injection. Photograph by Sigurdur Gislason

    Conventional methods for storing carbon dioxide underground pressurize and heat it to form a supercritical fluid, giving it the properties of both a liquid and a gas. While making the carbon dioxide easier to inject into the ground—usually in an old oil or gas reservoir—this carries a higher risk that it could escape back into the atmosphere through cracks in the rock.

    CarbFix takes carbon dioxide from the Hellisheidi geothermal power plant, the largest in the world, which uses volcanically heated water to power turbines. The process produces 40,000 tons of carbon dioxide a year, as well as hydrogen sulfide, both of which are naturally present in the water.

    3
    The CarbFix pilot injection site in March 2011. Photograph by Martin Stute

    The new study shows that more than 95 percent of the injected material turned to rock in less than two years. “No one actually expected it to be this quick,” says Edda Aradóttir, CarbFix’s project manager. The project is already storing 5,000 tons underground per year, making it the largest of its kind. New equipment being installed this summer aims to double the rate of storage.

    Aradóttir says CarbFix spends $30 per ton to capture and inject the carbon dioxide, versus $65 to $100 per ton for the conventional method. A lot of that savings comes from not having to purify the carbon dioxide; it and the hydrogen sulfide are simply mixed with additional water and injected underground.

    4
    CarbFix team members handle the rock core recovered from drilling at the CarbFix pilot injection site in October 2014. Photograph by Juerg Matter

    See the full article here .

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