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  • richardmitnick 3:50 pm on January 26, 2017 Permalink | Reply
    Tags: Advance in high-pressure physics, Atomic metallic hydrogen, Diamond anvil cell, Harvard   

    From Harvard: “Advance in high-pressure physics” 

    Harvard University
    Harvard University

    January 26, 2017
    Peter Reuell

    Harvard scientists announce they’ve created metallic hydrogen, which has been just a theory.


    Access mp4 video here .

    Nearly a century after it was theorized, Harvard scientists report they have succeeded in creating the rarest material on the planet, which could eventually develop into one of its most valuable.

    Thomas D. Cabot Professor of the Natural Sciences Isaac Silvera and postdoctoral fellow Ranga Dias have long sought the material, called atomic metallic hydrogen. In addition to helping scientists answer some fundamental questions about the nature of matter, the material is theorized to have a wide range of applications, including as a room-temperature superconductor. Their research is described in a paper published today in Science.

    “This is the Holy Grail of high-pressure physics,” Silvera said of the quest to find the material. “It’s the first-ever sample of metallic hydrogen on Earth, so when you’re looking at it, you’re looking at something that’s never existed before.”

    In their experiments, Silvera and Dias squeezed a tiny hydrogen sample at 495 gigapascal (GPa), or more than 71.7 million pounds per square inch, which is greater than the pressure at the center of the Earth. At such extreme pressures, Silvera explained, solid molecular hydrogen, which consists of molecules on the lattice sites of the solid, breaks down, and the tightly bound molecules dissociate to transforms into atomic hydrogen, which is a metal.

    While the work creates an important window into understanding the general properties of hydrogen, it also offers tantalizing hints at potentially revolutionary new materials.

    “One prediction that’s very important is metallic hydrogen is predicted to be meta-stable,” Silvera said. “That means if you take the pressure off, it will stay metallic, similar to the way diamonds form from graphite under intense heat and pressure, but remain diamonds when that pressure and heat are removed.”

    Understanding whether the material is stable is important, Silvera said, because predictions suggest metallic hydrogen could act as a superconductor at room temperatures.

    “As much as 15 percent of energy is lost to dissipation during transmission,” he said, “so if you could make wires from this material and use them in the electrical grid, it could change that story.”

    A room temperature superconductor, Dias said, could change our transportation system, making magnetic levitation of high-speed trains possible, as well as making electric cars more efficient and improving the performance of many electronic devices. The material could also provide major improvements in energy production and storage. Because superconductors have zero resistance, superconducting coils could be used to store excess energy, which could then be used whenever it is needed.

    Metallic hydrogen could also play a key role in helping humans explore the far reaches of space, as a more powerful rocket propellant.

    2
    Microscopic images of the stages in the creation of atomic molecular hydrogen: Transparent molecular hydrogen (left) at about 200 GPa, which is converted into black molecular hydrogen, and finally reflective atomic metallic hydrogen at 495 GPa. Courtesy of Isaac Silvera.

    “It takes a tremendous amount of energy to make metallic hydrogen,” Silvera explained. “And if you convert it back to molecular hydrogen, all that energy is released, so that would make it the most powerful rocket propellant known to man, and could revolutionize rocketry.”

    The most powerful fuels in use today are characterized by a “specific impulse” (a measure, in seconds, of how fast a propellant is fired from the back of a rocket) of 450 seconds. The specific impulse for metallic hydrogen, by comparison, is theorized to be 1,700 seconds.

    “That would easily allow you to explore the outer planets,” Silvera said. “We would be able to put rockets into orbit with only one stage, versus two, and could send up larger payloads, so it could be very important.”

    In their experiments, Silvera and Dias turned to one of the hardest materials on Earth, diamond. But rather than natural diamond, Silvera and Dias used two small pieces of carefully polished synthetic diamond and treated them to make them even tougher. Then they mounted them opposite each other in a device known as a diamond anvil cell.

    “Diamonds are polished with diamond powder, and that can gouge out carbon from the surface,” Silvera said. “When we looked at the diamond using atomic force microscopy, we found defects, which could cause it to weaken and break.”

    The solution, he said, was to use a reactive ion etching process to shave a tiny layer — just five microns thick, or about a tenth the thickness of a human hair — from the diamond’s surface. The diamond was then coated with a thin layer of alumina to prevent the hydrogen from diffusing into the crystal structure and embrittling it.

    After more than four decades of work on metallic hydrogen, and nearly a century after it was first theorized, it was thrilling to see the results, Silvera said.

    “It was really exciting,” he said. “Ranga was running the experiment, and we thought we might get there, but when he called me and said, ‘The sample is shining,’ I went running down there, and it was metallic hydrogen.”

    “I immediately said we have to make the measurements to confirm it, so we rearranged the lab … and that’s what we did.”

    See the full article here .

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    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 1:31 pm on January 19, 2017 Permalink | Reply
    Tags: , , Harvard, , ,   

    From Harvard: Women in STEM – “Strengthening ties among women in physics” 

    Harvard University

    Harvard University

    January 18, 2017
    Alvin Powell

    1
    An attendee at the Conference for Undergraduate Women in Physics examines equipment in the lab of Michael J. Aziz, the Gene and Tracy Sykes Professor of Materials and Energy Technologies. Photo by Silvia Mazzocchin

    When Margaret Morris looks around her physics class, sometimes she is the only woman there.

    Morris, a senior at Brandeis University, is living the reality for physics in the United States. At a time when women make up the majority of the country’s college students, their numbers still trail male peers in certain fields. And in some disciplines, like physics, women remain a small minority.

    Last weekend, 250 physics majors gathered at Harvard to take a collective step toward a new reality.

    The Conference for Undergraduate Women in Physics included lab tours, lectures, personal stories, and practical discussions about research, graduate school applications, how to deal with discrimination and implicit bias, and finding mentors.

    2
    Margaret Morris, a senior at Brandeis University, listens to a presentation at the Conference for Undergraduate Women in Physics. Morris was one of 250 physics majors in attendance. Photo by Silvia Mazzocchin

    Organizer Anne Hebert, a Harvard grad student, said the conference was designed to connect participants with a support network that will help them move ahead in the field.

    “As an undergraduate, obviously I noticed there weren’t many girls around,” Hebert said. “Every girl in physics has a moment when they turn their head and realize they’re the only girl in the room.”

    One of her fellow organizers, Ellen Klein, a Harvard doctoral student, said that as an undergrad at Yale University, she felt supported by faculty members and never experienced blatant gender discrimination. But she has noticed that there have been fewer women as she’s advanced through different academic levels.

    3
    Ellen Klein (not pictured), a Harvard Graduate School of Arts and Sciences doctoral student, said she’s noticed fewer women as she’s advanced through different academic levels. Photo by Silvia Mazzocchin

    Delilah Gates, also an organizing committee member and Harvard doctoral student, agreed with Klein and Hebert that bias, though often subtle, is still a problem. All three have heard male classmates joke about women and understood in a visceral way that, though real progress has been made, plenty of work remains.

    Gates added that as a black woman, she felt a lot of pressure in college to show that her opportunities weren’t handed to her because of race, leaving her temporarily conflicted about applying to graduate school.

    “In college, I kind of didn’t anticipate it. I was struck by the pressure I felt because of being an African-American woman and [proving] that no one was handing it to me because I check off a diversity box,” Gates said.

    The campus conference, organized through the American Physical Society, was one of 10 that took place across the United States and Canada and the first to be hosted by Harvard.

    4
    Suela Restelica, a sophomore at Orange County Community College in New York state, joined her fellow physics majors. Photo by Silvia Mazzocchin

    Some 1,500 women attended a session somewhere, Hebert said. A workshop titled SPIN UP, for Supporting Inclusion for Underrepresented Peoples, preceded the Harvard conference. The event was aimed at other underrepresented groups in the field, including minorities, students with disabilities, and students from low-income families.

    Physics helps solve problems facing humanity, said Masahiro Morii, chair of Harvard’s Physics Department, which provided logistical support for the student-run conference. And, though women make up half the population, they still make up less than 25 percent of physics graduate students.

    “Until it’s 50 percent, we’re still wasting a lot of talent that’s out there,” Morii said.

    See the full article here .

    Please help promote STEM in your local schools.

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    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 10:23 am on January 13, 2017 Permalink | Reply
    Tags: , , Harvard, , , Sugar stands accused   

    From Harvard: “Sugar stands accused” This Is Important for All 

    Harvard University

    Harvard University

    Sugar was in the dock at Harvard Law School this week, accused of a prime role in the twin epidemics of obesity and diabetes sweeping the country.

    1
    Gary Taubes signs copies of his book “The Case Against Sugar” following his talk for the Food Law and Policy Clinic. The acclaimed science writer hypothesizes that sugar “has deleterious effects on the human body that lead to obesity and diabetes, and that it should be considered a prime suspect [in the national dietary epidemic].” Stephanie Mitchell/Harvard Staff Photographer

    Science journalist and author Gary Taubes ’77 made his case that sugar consumption — which has risen dramatically over the last century — drives metabolic dysfunction that makes people sick. The hour-long talk was sponsored by the Food Law and Policy Clinic and drawn from Taubes’ new book, The Case Against Sugar.

    A reputation for “empty calories” — devoid of vitamins and nutrients but otherwise no different from other foods containing an equal number of calories — has allowed sugar to maintain a prominent place in the U.S. diet. Taubes is dubious. First, all calories are not equal because the body metabolizes different foods in different ways. More specifically, there may be something about eating too much sugar — in particular fructose, which is metabolized in the liver — that implicates it in metabolic disease.

    “I’m making an argument that sugar is uniquely toxic,” said Taubes. “It has deleterious effects on the human body that lead to obesity and diabetes.”

    Taubes laid out a case that he admitted was “largely circumstantial,” though one he considers compelling enough that it would gain at least an indictment from an impartial jury. The problem with the evidence, he said, is that public health researchers haven’t focused enough attention on sugar.

    “The research doesn’t exist beyond reasonable doubt that sugar is to blame,” Taubes said.

    Diabetes, Taubes noted, was once a rare disease. He traced its rise through the 1800s and 1900s from just a fraction of 1 percent of the cases seen at Massachusetts General Hospital to a condition that afflicts nearly 10 percent of the U.S. population, according to the Centers for Disease Control and Prevention. That increase, he said, coincides with an increase in sugar in the American diet.

    He tied today’s problems to both the sugar industry and some of the scientists responsible for informing the public about diet. Two researchers prominent in Harvard’s history didn’t escape blame: Elliott Joslin, the founder of the Harvard-affiliated Joslin Diabetes Center, and Frederick Stare, the founder of the Harvard T.H. Chan School of Public Health’s Nutrition Department.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 10:46 am on January 5, 2017 Permalink | Reply
    Tags: , , Harvard, , , , The Search for Extraterrestrial Genomes or SETG   

    From Many Worlds: “In Search of Panspermia” 

    NASA NExSS bloc

    NASA NExSS

    Many Worlds

    Many Words icon

    2017-01-05
    Marc Kaufman

    1
    This image is from the NASA Remote Sensing Tutorial. NASA

    When scientists approach the question of how life began on Earth, or elsewhere, their efforts generally involve attempts to understand how non-biological molecules bonded, became increasingly complex, and eventually reached the point where they could replicate or could use sources of energy to make things happen. Ultimately, of course, life needed both.

    Researchers have been working for some time to understand this very long and winding process, and some have sought to make synthetic life out of selected components and energy. Some startling progress has been made in both of these endeavors, but many unexplained mysteries remain at the heart of the processes. And nobody is expecting the origin of life on Earth (or elsewhere) to be fully understood anytime soon.

    To further complicate the picture, the history of early Earth is one of extreme heat caused by meteorite bombardment and, most important, the enormous impact some 4.5 billion years of the Mars-sized planet that became our moon. As a result, many early Earth researchers think the planet was uninhabitable until about 4 billion years ago.

    Yet some argue that signs of Earth life 3.8 billion years ago have been detected in the rock record, and lifeforms were certainly present 3.5 billion years ago. Considering the painfully slow pace of early evolution — the planet, after all, supported only single-cell life for several billion years before multicellular life emerged — some researchers are skeptical about the likelihood of DNA-based life evolving in the relatively short window between when Earth became cool enough to support life and the earliest evidence of actual life.

    1
    A DNA helix animation. Life on Earth is based on DNA, and some researchers have been working on ways to determine whether DNA life also exists on Mars or elsewhere in the solar system. No image credit.

    So what else, from a scientific as opposed to a religious perspective, might have set into motion the process that made life out of non-life?

    A team of prominent scientists at MIT and Harvard are sufficiently convinced in the plausibility of panspermia that they have spent a decade, and a fair amount of NASA and other funding, to design and produce an instrument that can be sent to Mars and potentially detect DNA or more primitive RNA.

    In other words, life not only similar to that on Earth, but actually delivered long ago from Earth. It’s called the The Search for Extraterrestrial Genomes, or SETG.

    Gary Ruvkun is one of those researchers, a pioneering molecular biologist at Massachusetts General Hospital and professor of genetics at Harvard Medical School.

    I heard him speaking recently at a Space Sciences Board workshop on biosignatures, where he described the real (if slim) possibility that DNA or RNA-based life exists now on Mars, and the instrument that the SETG group is developing to detect it should it be there.

    The logic of panspermia — or perhaps “dispermia” if between but two planets — is pretty straight-forward, though with some significant question marks. Both Earth and Mars, it is well known, were pummeled by incoming meteorites in their earlier epochs, and those impacts are known to have sufficient force to send rock from the crash site into orbit.

    Mars meteorites have been found on Earth, and Earth meteorites no doubt have landed on Mars. Ruvkun said that recent work on the capacity of dormant microbes to survive the long, frigid and irradiated trip from planet to planet has been increasingly supportive.

    “Earth is filled with life in every nook and cranny, and that life is wildly diverse,” he told the workshop. “So if you’re looking for life on Mars, surely the first thing to look for is life like we find on Earth. Frankly, it would be kind of stupid not to.”

    The instrument being developed by the group, which is led by Ruvkun and Maria Zuber, MIT vice president for research and head of the Department of Earth, Atmospheric and Planetary Sciences. It would potentially be part of a lander or rover science package and would search DNA or RNA, using techniques based on the exploding knowledge of earthly genomics.

    The job is made easier, Ruvkun said, by the fact that the basic structure of DNA is the same throughout biology. What’s more, he said, there about 400 specific genes sequences “that make up the core of biology — they’re found in everything from extremeophiles and bacteria to worms and humans.”

    Those ubiquitous gene sequences, he said, were present more than 3 billion years ago in seemingly primitive lifeforms that were, in fact, not primitive at all. Rather, they had perfected some genetic pathways that were so good that they still used by most everything alive today.

    And how was it that these sophisticated life processes emerged not all that long (in astronomical or geological terms) after Earth cooled enough to be habitable? “Either life developed here super-fast or it came full-on as DNA life from afar,” Ruvkun said. It’s pretty clear which option he supports.

    Ruvkun said that the rest of the SETG team sees that kind of inter-planetary transfer — to Mars and from Mars — as entirely plausible, and that he takes panspermia a step forward. He thinks it’s possible, though certainly not likely nor remotely provable today, that life has been around in the cosmos for as long as 10 billion years, jumping from one solar system and planet to another. Not likely, but at idea worth entertaining.

    Maria Zuber of MIT, who was the PI for the recent NASA GRAIL mission to the moon, has been part of the SETG team since near its inception, and MIT research scientist Christopher Carr is the project manager. Zuber said it was a rather low-profile effort at the start, but over the years has attracted many students and has won NASA funding three times including the currently running Maturation of Instruments for Solar System Exploration (MatISSE) grant.

    “I have made my career out of doing simple experiments. if want to look for life beyond earth helps to know what you’re looking for.

    “We happen to know what life on Earth is like– DNA based or possibly RNA-based as Gary is looking for as well. The point is that we know what to look for. There are so many possibilities of what life beyond Earth could be like that we might as well test the hypothesis that it, also, is DNA based. It’s a low probability result, but potentially very high value.”

    DNA sequencing instruments like the one her team is developing are taken to the field regularly by thousands of researchers, including some working with with SETG. The technology has advanced so quickly that they can pick up a sample in a marsh or desert or any extreme locale and on the spot determine what DNA is present. That’s quite a change from the pain-staking sequencing done painstakingly by graduate students not that long ago.

    Panspermia, Zuber acknowledged, is a rather improbable idea. But when nature is concerned, she said “I’m reticent to say anything is impossible. After all, the universe is made up of the same elements as those on Earth, and so there’s a basic commonality.”

    Zuber said the instrument was not ready to compete for a spot on the 2020 mission to Mars, but she expects to have a sufficiently developed one ready to compete for a spot on the next Mars mission. Or perhaps on missions to Europa or the plumes of Enceladus.

    he possibility of life skipping from planet to planet clearly fascinates both scientists and the public. You may recall the excitement in the mid 1990s over the Martian meteorite ALH84001, which NASA researchers concluded contained remnants of Martian life. (That claim has since been largely refuted.)

    Of the roughly 61,000 meteorites found on Earth, only 134 were deemed to be Martian as of two years ago. But how many have sunk into oceans or lakes, or been lost in the omnipresence of life on Earth? Not surprisingly, the two spots that have yielded the most meteorites from Mars are Antarctica and the deserts of north Africa.

    And when thinking of panspermia, it’s worthwhile to consider the enormous amount of money and time put into keeping Earthly microbes from inadvertently hitching a ride to Mars or other planets and moons as part of a NASA mission.

    The NASA office of planetary protection has the goal of ensuring, as much as possible, that other celestial bodies don’t get contaminated with our biology. Inherent in that concern is the conclusion that our microbes could survive in deep space, could survive the scalding entry to another planet, and could possibly survive on the planet’s surface today. In other words, that panspermia (or dispermia) is in some circumstances possible.

    Testing whether a spacecraft has brought Earth life to Mars is actually another role that the SETG instrument could play. If a sample tested on Mars comes back with a DNA signature result exactly like one on Earth–rather one that might have come initially from Earth and then evolved over billions of years– then scientists will know that particular bit of biology was indeed a stowaway from Earth.

    Rather like how a very hardy microbe inside a meteorite might have possibly traveled long ago.

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 9:36 am on December 22, 2016 Permalink | Reply
    Tags: , Diamonds are a lab’s best friend, Harvard, Tracking neural signals in the brain   

    From Harvard: “Diamonds are a lab’s best friend” 

    Harvard University
    Harvard University

    1
    PH.D. candidates Jenny Schloss (left) and Matthew Turner are co-authors of a recent paper on using nitrogen vacancy centers — atomic-scale impurities in diamond — to track neural activity. “We want to understand the brain from the single-neuron level all the way up, so we envision that this could become a tool useful both in biophysics labs and in medical studies,” said Schloss.
    Rose Lincoln/Harvard Staff Photographer

    Harvard researchers trace neural activity by using quantum sensors

    December 19, 2016
    Peter Reuell

    It’s one of the purest and most versatile materials in the world, with uses in everything from jewelry to industrial abrasives to quantum science. But a group of Harvard scientists has uncovered a new use for diamonds: tracking neural signals in the brain.

    Using atomic-scale quantum defects in diamonds known as nitrogen-vacancy (NV) centers to detect the magnetic field generated by neural signals, scientists working in the lab of Ronald Walsworth, a faculty member in Harvard’s Center for Brain Science and Physics Department, demonstrated a noninvasive technique that can image the activity of neurons.

    The work was described in a recent paper in the Proceedings of the National Academy of Sciences, and was performed in collaboration with Harvard faculty members Mikhail (Misha) Lukin and Hongkun Park.

    “The idea of using NV centers for sensing neuron magnetic fields began with the initial work of Ron Walsworth and Misha Lukin about 10 years ago, but for a long time our back-of-the-envelope calculations made it seem that the fields would be too small to detect, and the technology wasn’t there yet,” said Jennifer Schloss, a Ph.D. student and co-author of the study.

    “This paper is really the first step to show that measuring magnetic fields from individual neurons can be done in a scalable way,” said Ph.D. student and fellow co-author Matthew Turner. “We wanted to be able to model the signal characteristics, and say, based on theory, ‘This is what we expect to see.’ Our experimental results were consistent with these expectations. This predictive ability is important for understanding more complicated neuronal networks.”

    At the heart of the system developed by Schloss and Turner, together with postdoctoral scientist John Barry, is a tiny — just 4-by-4 millimeters square and half a millimeter thick — wafer of diamond impregnated with trillions of NV centers.

    The system works, Schloss and Turner explained, because the magnetic fields generated by signals traveling in a neuron interact with the electrons in the NV centers, subtly changing their quantum “spin” state. The diamond wafer is bathed in microwaves, which put the NV electrons in a mixture of two spin states. A neuron magnetic field then causes a change in the fraction of spins in one of the two states. Using a laser constrained to the diamond, the researchers can detect this fraction, reading out the neural signal as an optical image, without light entering the biological sample.

    In addition to demonstrating that the system works for dissected neurons, Schloss, Turner, and Barry showed that NV sensors could be used to sense neural activity in live, intact marine worms.

    “We realized we could just put the whole animal on the sensor and still detect the signal, so it’s completely noninvasive,” Turner said. “That’s one reason using magnetic fields offers an advantage over other methods. If you measure voltage- or light-based signals in traditional ways, biological tissue can distort those signals. With magnetic fields, though the signal gets smaller with stand-off distance, the information is preserved.”

    Schloss, Turner, and Barry were also able to show that the neural signals traveled more slowly from the worm’s tail to its head than from head to tail, and their magnetic field measurements matched predictions of this difference in conduction velocity.

    While the study proves that NV centers can be used to detect neural signals, Turner said the initial experiments were designed to tackle the most accessible approach to the problem, using robust neurons that produce especially large magnetic fields. The team is already working to further refine the system, with an eye toward improving its sensitivity and pursuing applications to frontier problems in neuroscience. To sense signals from smaller mammalian neurons, Schloss explained, they intend to implement a pulsed magnetometry scheme to realize up to 300 times better sensitivity per volume. The next step, said Turner, is implementing a high-resolution imaging system in hopes of producing real-time, optical images of neurons as they fire.

    “We’re looking at imaging networks of neurons over long durations, up to days,” said Schloss. “We hope to use this to understand not just the physical connectivity between neurons, but the functional connectivity — how the signals actually propagate to inform how neural circuits operate over the long term.”

    “No tool that exists today can tell us everything we want to know about neuronal activity or be applied to all systems of interest,” Turner said. “This quantum diamond technology lays out a new direction for addressing some of these challenges. Imaging neuron magnetic fields is a largely unexplored area due to previous technological limitations.”

    The hope, Schloss said, is that the tool might one day find a home in the labs of biomedical researchers or anyone interested in understanding brain activity.

    “We want to understand the brain from the single-neuron level all the way up, so we envision that this could become a tool useful both in biophysics labs and in medical studies,” she said. “It’s noninvasive and fast, and the optical readout could allow for a variety of applications, from studying neurodegenerative diseases to monitoring drug delivery in real time.”

    Walsworth credits the leadership of Josh Sanes, the Paul J. Finnegan Family Director of the center, and Kenneth Blum, executive director, for enabling this biological application of quantum diamond technology. “Center for Brain Science leadership provided the essential lab space and a welcoming, interdisciplinary community,” he said. “This special environment allows physical scientists and engineers to translate quantum technology into neuroscience.”

    See the full article here .

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    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 1:33 pm on December 8, 2016 Permalink | Reply
    Tags: , Harvard, ,   

    From Harvard: “Colorful clones track stem cells” 

    Harvard University

    Harvard University

    November 23, 2016 {Just found this in social media.]
    Hannah Robbins, HSCI Communications

    1

    Harvard Stem Cell Institute (HSCI) researchers have used a colorful cell-labeling technique to track the development of the blood system and trace the lineage of adult blood cells traveling through the vast networks of veins, arteries, and capillaries back to their parent stem cells in the marrow.

    Developed at Harvard’s Center for Brain Science, the technique involves coding multiple colors of fluorescent protein into a cell’s DNA. As genes recombine inside the cell, the cell elaborates a color unique to its genetic code. For blood stem cells, that color becomes a genetic signature passed down to daughter cells; purple stem cells, for example, will only make purple blood cells.

    Two independent research teams, one led by David Scadden, HSCI co-director and Gerald and Darlene Jordan Professor of Medicine at Harvard University, and the other by his colleague Leonard Zon, HSCI Executive Committee member and director of the Stem Cell Program at Boston Children’s Hospital, adapted the color-based labeling to the blood system to better understand how blood stem cells behave.

    In a study recently published in Cell, a research team led by Scadden found that in mice individual blood stem cells had a specific and restricted blood production repertoire.

    “We used to think of stem cells as the mother cell that gives rise to all these other cells in the system on an as-needed basis,” said Vionnie Yu, first author of the study and, at the time of the research, a postdoctoral fellow in Scadden’s lab. But their results suggest that stem cells have a scripted set of responses and cannot make just any blood cell type.

    When transplanted into a new environment, each cell not only consistently made the same mature blood cell types but also the same number of those cells. Additionally, clones responded similarly to inflammatory and chemotoxic stress, suggesting the cells had a hardwired memory dictating their behavior. They found that this memory was written into the stem cell epigenome.

    Blood stem cells, said Scadden, may be more like chess pieces with a fixed way they can behave within the system.

    “When you are young and have a full chess set you can mount a vigorous and multilayered defense to an attack on your system,” Scadden said, “but if you lose chess pieces with age or you don’t receive a full suite of players during a bone marrow transplant, the pieces you have left could determine your ability to protect yourself.”

    In addition to looking at blood stem cells in adult mice, color tagging also allows researchers to explore the blood system as a zebrafish embryo develops.

    “We’ve been working with David Scadden for years as part of the HSCI. Initially, we presented our work at a joint lab meeting and realized we could study stem cell clones with this multicolor system,” said Zon, who is also a professor in Harvard’s Stem Cell and Regenerative Biology department. “We shared ideas and results, and even wrote a grant together on the topic. It is wonderful that studying clonal dynamics in two different animals could provide such complementary information.”

    In a study published Monday in Nature Cell Biology, the researcher team led by Zon used the color-tagging system to find the origin and number of stem cells that contribute to lifelong blood production.

    About 24 to 30 hours after fertilization, dozens of stem cells budded off from the dorsal side of the aorta. Only 20 made it to a secondary site before heading to the kidney marrow, the zebrafish equivalent to human and mouse bone marrow.

    After transplanting the multicolored marrow into fish that had received sublethal doses of radiation, the researchers found that some blood stem cell lineages supplied a greater proportion of blood than they had before and that certain lineages could survive harsher conditions than others.

    Knowing which cells are responsible for blood production could have implications for understanding the development of blood cancers, explained Jonathan Henninger, a graduate student in Zon’s lab at Boston Children’s Hospital and first author in the study.

    For example, one cell could develop a mutation that gives it a competitive edge, allowing it to take over the blood system.

    “If that cell starts behaving badly, it could lead to blood disorders, such as myeloid dysplasia and leukemia,” Henninger said.

    Researchers know these disorders come from a single stem cell or a downstream progenitor cell, said Henninger, but right now they are looking at populations of stem cells in bulk. “To be able to identify that single cell that went awry could help us better understand these diseases.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 9:22 am on December 7, 2016 Permalink | Reply
    Tags: , , Harvard, Professor Pier Paolo Pandolfi   

    From Harvard: “Fresh ways to fight cancer” 

    Harvard University
    Harvard University

    December 6, 2016
    Alvin Powell

    1
    Professor Pier Paolo Pandolfi speaks about revolutionary developments in cancer care and how he sees treatment evolving. “We will defeat cancer. Conceptually, we can. But it will take time.”
    Stephanie Mitchell/Harvard Staff Photographer

    In recent years, cancer patients have benefited from a new array of weapons to fight the disease. Traditional chemotherapy and radiation therapy — blunt clubs aimed at any fast-growing cell in the body — have been augmented by “targeted therapy” drugs that interfere with specific cellular functions in an attempt to block cancer growth.

    More recently, therapies that unleash the body’s immune system on cancer have been making their way to the clinic, offering new “immunotherapy” weapons in what has become an expanding clinical arsenal.

    Researchers came to Boston in November for a daylong symposium on curing cancer. The session at Beth Israel Deaconess Medical Center (BIDMC) was hosted by Pier Paolo Pandolfi, George C. Reisman Professor of Medicine at Harvard Medical School and director of BIDMC’s Cancer Center and Cancer Research Institute.

    Pandolfi talked to the Gazette about the encouraging progress in the fight against cancer and about a promising new avenue of investigation opened by the discovery of another type of RNA.

    GAZETTE: You wrote in 2013 that we’re in a period of unprecedented opportunity in cancer research. Do you still believe that, and, if so, why?

    PANDOLFI: Absolutely. … I haven’t changed my mind a bit. Actually, there is more enthusiasm now, and our symposium was a testament to the enthusiasm. It was well attended because everyone is [asking] about the revolution in immune therapy. … But there is a second aspect, which is the noncoding RNA revolution. I don’t know if you’ve heard about it?

    GAZETTE: What can you tell me about it?

    PANDOLFI: This eye-opening, almost inconvenient truth emerged that our genome is a bit more complex than anticipated.

    We are [now] able to not only sequence the genome, but to sequence the transcriptome, the RNA that comes from the DNA.

    We realized that our protein-coding genome is only 2 percent of the [entire genome], [but] the rest of the genome — the other 98 percent — is not silent and does more than regulate protein-coding gene expression. In fact, it’s heavily transcribed and … at last count, we may have as many as 100,000 RNAs in our cells that don’t code for proteins.

    These include circular RNAs, circRNAs, which we didn’t see until now because we didn’t have the bioinformatics tools. Now, we appreciate that this species is one of the most abundant RNAs in our cells.

    We discovered that these RNAs are functional or profoundly dysfunctional, driving disease as well as protein-coding genes. This new knowledge will allow us to find new disease genes, to develop new drugs and new medicines. We are talking about RNA medicine. In our Cancer Center, we launched the Institute for RNA Medicine, a research initiative [that] is expected soon to become Harvard-wide.

    GAZETTE: What about treatments in the mainstream today or moving into the mainstream?

    PANDOLFI: There are two major breakthroughs. One is the targeted therapy revolution.

    Conceptually, we’ve moved from chemotherapy and radiotherapy, which are based on the only thing that we [once] knew about cancer: that it is characterized by proliferation.

    The idea was that if you block proliferation, the cancer will suffer. [But] resistance ensues, and toxicity is huge because our body also has [noncancer] cells that proliferate.

    Then we discovered cancer is driven by protein-coding genes. … We could develop drugs that do not necessarily kill the cancer cell, but rather fix the molecular problem [within the cell].

    This approach led to great success. The reason why I’m here and director of this Cancer Center is … the story of a leukemia, APL [acute promyelocytic leukemia], which we cured.

    We developed a combinatorial treatment, which eradicated the disease. We found two drugs that go after the oncogene. Now this concept is accepted, with hundreds of targets, hundreds of oncogenes or tumor suppressors. The pharmaceutical industry is working hard in that space.

    The second new weapon is immune therapy. Cancer cells shut down the immune response in many ways. Cancer basically develops a shield to protect itself from the immune system. Now scientists have cracked this shield with approaches that go after it and break it down.

    The fruition of this new approach is what we are experiencing now. There are immune therapies that can really cure, meaning you can deploy the drug that breaks the shield and the immune system wipes the cancer out. The beauty of all this is … you can develop vaccines.

    You can create vaccines whereby the immune system remembers … so if there’s residual disease, as soon as the cancer tries to resurface, it will be again attacked by the immune system.

    GAZETTE: We know a lot more about cancer than we did before, but part of what we know is that even within different types of cancer — lung cancer, liver cancer, breast cancer — there are different genetic profiles …

    PANDOLFI: We already know that cancer is not one disease, but many. Complexity is very high.

    So the challenge is twofold. We have hundreds of new [drug candidate] molecules, for each and every pathway of cancer. The first hurdle is to understand very rapidly which cancer they may work on, which cancer they may not, and why.

    Then, say the cancer [has] many mutations. Which mutation would confer resistance to that drug, and which combination of drugs will overcome that resistance? How can we combine them with immune therapies? The challenge now is how do we test all these things because if we did it in a human being, it would take forever.

    We came up with this idea of the “mouse hospital,” which is one of the signatures of our Cancer Center. We re-created the complexity of human cancer at three levels.

    First, we made mice that are genetically engineered to harbor all these genes that we are talking about, and now the noncoding RNAs. So the idea is to make a mouse which is a phenocopy of the cancer of Mr. Smith, who is treated at the Cancer Center, by engineering the mouse to express the genes of Mr. Smith.

    The second way is that you take the tumor of Mr. Smith, a biopsy, and you put it in a mouse. This is called an “avatar approach” or “patient-derived xenograft.” So you put the tumor in a mouse, and then you retransplant it in many mice. You have 100 mice, then you treat them with several drugs to very quickly understand which [drug] would work and which one would not.

    Meanwhile, Mr. Smith gets his standard therapy. They offer him drug X, then he fails and they offer him drug Y. As soon as he fails everything standard, there is what I call the panic phase. If you have the [mouse] avatar, while the patient is given the standard treatment, you can find a new drug or new drug combination that you can offer.

    The third approach is even faster. Again, Mr. Smith comes to the center, we biopsy his tumor or we take a leukemia sample and we put it in a [lab] dish. We grow mini tumors — organoids — and again test with several drugs. The organoid has the advantage that it is much less expensive and much faster. You can go from biopsy to drug testing in a matter of weeks.

    The next hurdle is very simple: Who pays for it? Maybe we’ll convince the insurers to pay for organoids. You don’t want to spend a huge amount of money to give Mr. Smith a drug that doesn’t work. So … why don’t you give us a little more money to do genotyping analysis and organoids? This prescreening allows you to know if the drug is needed.

    But we are not yet there. [Now] this approach is funded by government through grants, by philanthropy, and by the cancer center.

    GAZETTE:: How long until these new therapies become the standard of care? People are still getting chemo and radiation therapy …

    PANDOLFI: This is a big ongoing argument. We still offer a standard of care that is oftentimes obsolete. We know it doesn’t work. Why don’t we flip the approach? Why don’t we offer the targeted therapies first and then maybe we follow with the standard of care?

    The other thing happening now is the need to deliver combination therapy. But the FDA still doesn’t allow you to try a combination or cocktail of drugs in [clinical trials]. You have to do it one at a time, which is never-ending. There are a number of people who are pushing to do a cocktail of drugs up front. You would combine them all and do phase 1 and phase 2 and phase 3 [trials].

    At the moment all this is done, almost invariably, at the end of the journey when the panic phase ensues.

    GAZETTE: And when the person is much sicker.

    PANDOLFI: And when the patient is much sicker, when the cancer is much more complex because it has evolved in your body.

    The last point I would make is that there is only one way to fight the complexity of cancer, which is to diagnose it earlier and earlier and earlier. We will defeat cancer. Conceptually, we can. But it will take time.

    We need to push the envelope [of] early diagnosis. [If] you have three nanoparticles in your body that signal there is something wrong, you go in and take them out. If you can do that, you’re treating a cancer which is simpler … the genetic complexity is smaller, the size is smaller, and the targeted therapy and immune therapy will be much easier to deploy.

    I think the noncoding RNA will help. We need to find biomarkers that we can use and can monitor on almost a regular basis. We will probably introduce a panel of genes or RNAs that you can detect in your blood that will spy for possible cancer development.

    GAZETTE: Would you do that every year at your annual checkup?

    PANDOLFI: Why not? Men over 50 have the PSA [prostate specific antigen] test … and the PSA is one marker. Imagine that you can test 100 markers and increase the accuracy. You have a test that is all cancer, “pan-cancer,” you have 50 genes, and you are sure that if one of them is regulated, it’s either prostate or colon. You follow up with imaging and if you find something wrong, you get it out.

    GAZETTE: Which cancers do you think are most likely to be cured?

    PANDOLFI: The ones for which we have more knowledge. Although leukemia is not entirely cured, the first successes that we experienced were in leukemias, the first real cures were in leukemias.

    The other factor is that you need to have some time to play the game, so I think slowly developing cancers that give time to the operators to use this panoply of drugs, such as prostate cancer or cancers that are already impacted by current therapies, will be cured first.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 8:46 am on October 13, 2016 Permalink | Reply
    Tags: , , , , Harvard,   

    From Harvard: “They ponder the universe” 

    Harvard University

    Harvard University

    October 12, 2016
    Alvin Powell

    Harvard students join faculty at CERN in Europe to tackle physics’ mysteries


    Access mp4 video here .

    Once you know enough math, Harvard Ph.D. student Tony Tong said, you get to know physics. And physics, he said, is simply amazing.

    “[Physics] is always helpful to answer the question of ‘Why?’ Why the skies are blue, why the universe is so big, basic stuff,” Tong said. “I’m always curious about those questions and the solution is always so beautiful.”

    Tong, it seems, had come to the right place. He was speaking on a warm July day in a small courtyard at the European Organization for Nuclear Research, known as CERN, the scientific campus on the outskirts of Geneva that is the world’s beating heart for high-energy particle physics.

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Home of the world’s most powerful particle accelerator, the Large Hadron Collider (LHC), CERN made world headlines in 2012 when scientists announced the discovery of the Higgs boson, the final undiscovered particle in the theoretical framework of the universe called the Standard Model.

    CERN CMS Higgs Event
    CERN CMS Higgs Event

    CERN ATLAS Higgs Event
    CERN ATLAS Higgs Event

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.
    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    The eyes of the scientific world remain focused on CERN today because the LHC is back in operation after a major upgrade that boosted its energy to 13 tera electron volts, allowing it to crash beams of protons into each other more powerfully than ever before. Now that the Standard Model is complete, scientists are looking for what’s still mysterious, sometimes called the “new physics” or “physics beyond the Standard Model.” Its form, presumably, would involve a particle born of these high-energy collisions, one that points the way to an even broader understanding of the universe, shedding light on such puzzling areas as dark matter, supersymmetry, dark energy, and even gravity, which has stubbornly refused to fit neatly into our understanding of the universe’s basic forces.

    Standard model of Supersymmetry DESY
    Standard model of Supersymmetry DESY

    CERN fired up its first accelerator in 1957. Among its milestone discoveries are the elementary particles called W and Z bosons, antihydrogen — the antimatter version of the common element — and the creation of the World Wide Web to share massive amounts of information among scientists, scattered at institutions around the world.

    The CERN campus, which straddles the Switzerland-France border amid breathtaking views of the distant Alps, produces more than just science, however. In ways technological, theoretical, educational, and inspirational, it also produces scientists.


    Access mp4 video here .
    Inside the Antimatter Factory at CERN, the ATRAP antimatter experiment seeks to slow and trap antimatter for comparison with ordinary matter.

    CERN ATRAP New
    CERN ATRAP

    “Those four years at CERN doing research were a very important part of my training,” said Harvard Physics Department chair Masahiro Morii, who was a research scientist at CERN early in his career. “It taught me things that are a bit difficult to quantify, but changed my perspective very drastically on what it means to be a scientist, what it means to be a high-energy physicist.”

    Year-round, the graduate students and postdoctoral fellows taking their initial career steps work among established scientists, learning and gaining experience difficult to get outside of CERN or a handful of other facilities around the world. Harvard’s Donner Professor of Science John Huth said what becomes apparent is science’s messiness.

    “They see the process as it unfold with all its warts. Science is pretty messy when you get into the nitty-gritty,” Huth said. “It’s just an invaluable experience. Even if you become a scientist in a different discipline or you leave science entirely, understanding that intrinsic messiness is really important.”

    In an environment focused on the practice of physics rather than the teaching of it, CERN puts the onus for learning onto the student, Morii said. Students build and test equipment, make sure what’s installed is running properly, and pluck the most meaningful pieces from the resulting data tsunami. They analyze it at all hours of the day and sometimes deep into the night, since there’s always someone awake and logged onto Skype to answer a question or share an insight.

    “People are really passionate, so it doesn’t really feel like you’re up until 11 doing your job. Maybe you’re thinking about something on the train home and you wanted to look into it. It’s not regular hours, but I don’t think that deters anyone,” said Harvard physics Ph.D. student Julia Gonski. “People like the work and it’s fun. Twenty-four hours a day, you can get on Skype and someone you know is on Skype and working.”

    While fellows and graduate students are at CERN year-round, each summer the campus’ population swells as undergraduates eager to take part in the world’s most famous science experiment step off the plane in Geneva.

    At CERN, they become part of a unique city of physicists from around the world, with different educational and cultural backgrounds but the same passions and similar goals.

    “It was this enormous scientific laboratory, with thousands of people working all hours of the night trying to understand the fundamentals of the universe, as corny as that is to say,” said Harvard postdoctoral fellow Alexander Tuna, who first came to CERN as a summer undergrad from Duke University in 2009. “It was really immersive and fun. There’s always someone around with an interesting insight or an answer to a question.”

    The secrets of the universe

    As a visitor approaches CERN, the giant brown orb of the multistory Globe of Science and Innovation comes into view.

    The globe, looking like an enormous particle half-buried in the earth, serves as a CERN welcome center and is far more visually appealing than the main campus across the street. Protected by fences with access limited through guard stations, the campus’ narrow, twisting roadways wind between boxy, industrial-looking buildings numbered instead of named, as if creativity there is reserved for science instead of infrastructure. Even the cafeteria that serves as a central gathering spot is named simply “Restaurant 1.”

    “It was different than I expected,” said Harvard junior Matthew Bledsoe. “I figured a place on the forefront of physics would look fresher and newer, new buildings and stuff. But [they are] 1950s and ’60s-era buildings, so the buildings are pretty old. It looks like a factory.”

    Visitors quickly learn to look past the boxy exteriors to what’s inside. There they find thousands of people working on 18 experiments, seven associated with the LHC and the others with smaller accelerators and a decelerator, which is used for antimatter experiments like those run by Harvard Physics Professor Gerald Gabrielse’s ATRAP collaboration.

    ATRAP, short for “antihydrogen trap,” relies on the LHC’s high energy to make protons collide with a target to create antiprotons. The experiment then cools and slows the antiprotons, and combines them with positrons, the antimatter equivalent of electrons, to create antihydrogen for study and comparison with ordinary hydrogen. Gabrielse, who pioneered antimatter experiments at CERN, said that for students who want to go into high-energy physics, getting a taste of the enormous collaborations that are behind such experiments is key.

    “If you’re interested in making a career in doing those kinds of things [experimental particle physics], it’s extremely important to have this experience,” Gabrielse said.

    The LHC, with its potential to pierce the veil between the known world of the Standard Model and the mysteries that the model does not address, takes center stage. Yet to visitors wandering the halls and sidewalks of CERN, the LHC is nowhere to be seen.

    That’s because the LHC is buried 300 feet underground in a massive tunnel that runs 17 miles from Switzerland into France and back again. Its twin proton beams circle in opposite directions, crossing four times on their journey. At those crossings are four major particle detectors, one of which is ATLAS, a massive machine backed by a worldwide collaboration in which Harvard scientists play lead roles, and which was one of two experiments to detect the Higgs boson.

    CERN/ATLAS detector
    CERN/ATLAS detector

    2
    Outside the ATLAS control room at the LHC. Joe Sherman/Harvard Staff Photographer

    “You can think of it (ATLAS) as a really large camera surrounding the collision point where protons collide,” Tuna said.

    ATLAS, which stands for A Toroidal LHC Apparatus, is 180 feet long, 82 feet in diameter, and weighs 7,000 tons. When the proton beams collide, they scatter particles in all directions. ATLAS dutifully records these collisions, producing far more data than current computing technology can store, so filters are employed that screen out more mundane results and keep only the most promising for analysis.

    The complex undertaking requires a collaboration that is as massive as the task the researchers have set for themselves. It includes about 3,000 physicists from 175 institutions in 38 countries.

    “This is the center of particle physics right now,” said Harvard Ph.D. student Karri DiPetrillo. “As a scientist, you like asking nature questions and seeing what the answer is. Because we have thousands of people working on a single experiment, you know we’re asking some of the hardest questions in the universe. If it takes thousands of people to find the answer, you know that it’s a good question.”

    For decades, physicists exploring the most basic particles that make up the universe were guided by the Standard Model, which held that everything is made of a limited number of quarks, leptons, and bosons. Over the years, one by one, experimental physicists, including Harvard faculty members, found the particles predicted by the theory: bottom quark, W boson, Z boson, top quark. In 2012, they found the Higgs boson, the last theorized particle.

    When the huge hubbub over the Higgs discovery faded, particle physicists began to assess the field’s new reality. After decades in which theoretical physicists were leading, telling experimental physicists what new particle to look for, the roles are now reversed.

    As reliable as the Standard Model has been, it doesn’t explain everything. And, while theoretical physicists have several ideas of where those mysteries might fit into current knowledge, no evidence exists to tip the scales toward one idea or another.

    Even the Higgs boson still holds secrets, as detecting it didn’t completely explain it. Scientists who continue to probe the Higgs boson hope that the particle may yet reveal clues — inconsistencies from what is expected from the Standard Model — that will outline the broader path forward.

    “There are really two paths. One path is to really push on what we understand about the Higgs boson because that has the strangest properties associated with it and if you push the theory at all the Higgs creates the most problems for it,” Huth said. “The other is the discovery region for something new, like dark matter.”

    The undergraduate summer

    A scientist’s path to CERN usually starts with a passion for physics. Graduate student Nathan Jones credits a family road trip to Colorado during which he read a library book about the universe. Undergrad Bledsoe was wowed by a trip to Fermilab outside Chicago as a high school freshman, while grad student Gonski traces it to the annoyance she felt when she learned her high school chemistry teacher had gotten the science wrong.

    “I remember being in chemistry class in high school when they told us protons and neutrons are indivisible,” said Gonski, who learned otherwise from Stephen Hawking’s “A Brief History of Time.” “I was so offended … I remember being frustrated and asking my parents, ‘Did you guys know?’ At that point I wanted to see how far down we can go [in particle size].”

    After that initial spark, students take classes and often work in a campus laboratory before heading overseas. Some undergraduates go to CERN through the Undergraduate Summer Research Experience program run by the University of Michigan for students across the country. Several Harvard students benefitted instead from the Weissman International Internship Program Grant, established in 1994 to provide faraway opportunities for them.


    Access mp4 video here .
    A field of sunflowers stands at the roadside on the approach to CERN.

    Once the funding is set, there’s nothing left but the plane ride and moving into their new digs. Undergraduates live in settings ranging from downtown Geneva to the French countryside. Last summer, three Harvard students — Ben Garber ’17, Gary Putnam ’17, and Bledsoe — rented an apartment over the border in France and commuted to work each day by bike, while Katie Fraser ’18 stayed closer, at CERN’s on-campus hostel.

    Days consisted of morning lectures on topics relevant to their work. After those lectures — and the occasional pickup basketball game at lunchtime — they’d spend afternoons working on a project. Garber worked with Tuna and DiPetrillo on an analysis of Higgs boson decay (the particle itself exists for a tiny period of time) into two W bosons. Bledsoe worked on hardware, building and testing a circuit board to be used in the planned 2018 ATLAS upgrade, in the cavernous Building 188 under the tutelage of Theo Alexopoulos from the Technical University of Athens. Wherever they were, whether doing project tasks or having cafeteria conversations, the students were steeped in physics.

    “It was a lot of fun, different than I expected. You learn stuff just by being there, pick up vocabulary in lunchtime conversations,” Fraser said. “It definitely solidified my desire to go into high-energy physics.”

    Melissa Franklin, Mallinckrodt Professor of Physics, said lessons can be found behind almost every door at CERN.

    “I was just amazed, it was unbelievable,” said Franklin, who first visited between her undergraduate and graduate years. “I went to every place I could on site and just knocked on doors and bugged people … You learn so much by osmosis. You have to learn to hang around and ask good questions.”

    Jennifer Roloff, a Harvard physics Ph.D. student, first came to CERN in 2011 as an undergraduate and has been back every summer. Now she helps manage the University of Michigan summer undergraduate program, which gives her a broad view of the student experience.

    “There are definitely some students who do miss home,” Roloff said. “For a lot of them it’s the first time out of the country [or] the first time long-term out of the country. For a lot of them, they realize this is not what they want to do. CERN is not for everyone. There are challenges and difficulties that are not in other physics.”

    That understanding, Gabrielse said, is as important a lesson as finding your intellectual home.

    “Some decide, based on it, to go into the field. Some decide not to,” Gabrielse said. “That guidance too is valuable.”

    Yet being at CERN is not just about science. Students have their weekends free and can explore their new surroundings. Some hike the Alps or the closer Jura Mountains. Others walk the ancient streets of Geneva, visiting its lakefront, restaurants, museums, and other attractions. Putnam loved a park near the University of Geneva where people played on large chessboards with giant pieces. He also soaked up the area’s natural splendor.

    “It’s so beautiful here,” Putnam said. “Sometimes I forget and do the normal thing of looking down and not paying attention, but being able to look up and see the mountains is really special.”

    On call for a particle emergency

    Life at CERN as graduate students is not quite so fancy-free. Visits are limited to summers early in graduate careers as they complete coursework, but once that’s done, they can come and stay to conduct dissertation research.

    To keep the ATLAS collaboration running, graduate students are required to spend a year of research time doing work to benefit the experiment itself, to ensure that high-quality data is collected, for example, or that potentially significant collision events aren’t lost in the data.

    “We have to make sure the data we’re receiving is like you expect it, ready for analysis,” DiPetrillo said. “[It’s taken] probably half of my time in the last year; the other half has been working on Standard Model measurement of the Z boson.”

    5
    A little physicist humor written on a CERN blackboard. Joe Sherman/Harvard Staff Photographer

    Part of DiPetrillo’s duty is assisting in ATLAS’ day-to-day operation, working in the ATLAS control room — with its Mission Control feel, and dominated by a wall-sized screen — and monitoring one of several subsystems that make the whole operation work. Monitoring those subsystems makes ATLAS a 24/7 proposition.

    In addition to working overnight in the control room, DiPetrillo is often on call to back up someone on site. While on call, she has to stay near her phone and within an hour’s drive of the facility in case something goes wrong. If that happens, she troubleshoots the problem with the person in the control room or pushes the problem up to someone more senior.

    “You can think of ATLAS as always taking data so we always need people watching it, making sure ATLAS is working in a way that we want [it] to, that the detector is working … and that data looks the way we expect,” DiPetrillo said.

    When not on call or manning the control room overnight, a graduate student’s life at CERN is full of meetings to share and hear the latest findings, and of hours poring over the latest data looking for the kind of statistical bump that might indicate a new particle — or a new something else.

    The LHC’s recent upgrade has made scientists hopeful that a new particle will be discovered soon. But if not, another upgrade planned for about 2018 may do the trick. While the recent upgrade made the energy of the proton beam higher, the next one will increase luminosity, or the number of protons in the beam, multiplying the number of collisions at any given moment and improving the odds of detecting extremely rare events.

    “We’re all here to … discover stuff, but it’s so difficult. It’s impossible to do as one person,” Gonski said. “I would love to be one person on the 500-person team to discover [supersymmetry’s] stop quark. It’d be great for physics if we all discovered this and for me to say I want to do this — be a tiny fraction of a large group effort.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 7:53 am on October 6, 2016 Permalink | Reply
    Tags: "Energy and Climate: Vision for the Future", , , Harvard, Michael McElroy   

    From Harvard: “A way forward on climate” 

    Harvard University

    Harvard University

    October 5, 2016
    Alvin Powell

    1
    Atop the roof of the Science Center with solar panels in the background, SEAS/EPS Professor Michael McElroy talks about his new book, Energy and Climate: Vision for the Future, on the global energy challenge with climate change.

    Headlines focus on international agreements, sea levels, melting ice, and superstorms, but climate change is most of all an energy problem. Burning fossil fuels to power our cars and heat our homes produces carbon dioxide that transforms the atmosphere into a greenhouse, trapping heat that otherwise would radiate into space.

    While the fundamentals are solid, everything else about climate change is evolving. Climate science is advancing and economic pressures have dramatically altered the national fuel mix — for the better, most agree, though we still have miles to go. Even the political landscape that determines national climate action — or inaction — is in flux.

    Michael McElroy, Gilbert Butler Professor of Environmental Studies, has long helped explain the complexities of climate to students, scholars, and government leaders. His most recent book, Energy and Climate: Vision for the Future, published in August by Oxford University Press, is a continuation of that work. He discussed the book in a recent interview with the Gazette.

    2

    GAZETTE: In Energy and Climate, you talk about the U.S. energy picture being transformed over the last five years in ways that may make needed changes regarding climate tougher to accomplish. How has the U.S. energy scene changed into the one we’re in now?

    McELROY: The big change is that we no longer have the previous driving concern about national energy security. What has made the difference was the shale revolution. Ten years ago we were projecting that the U.S. would not only be dependent on imports for oil but also for natural gas. We now have a surplus of both. The U.S. is presently a net exporter of petroleum products. Prices for both natural gas and oil have plummeted. I had a student who wrote a beautiful senior thesis four or five years ago, in which he tried to analyze the break-even price for production of natural gas from shale. His conclusion was it would be about $5 per million BTU at a time when natural gas prices — wholesale prices — were $7, $8, $9. Now they’re below $3. So it’s a different world. Oil prices were $168 a barrel in 2008 just before the economic crisis. They are now below $50.

    The U.S. also has abundant sources of coal. Were it not for the climate issue, we could contemplate taking advantage of this resource also, doing so as efficiently as possible to eliminate conventional sources of pollution such as sulfur and nitrogen oxides and particulates. Emissions of CO2 could go through the roof under these scenarios. There is no cost-effective means to capture CO2. Concerning the potentially expanded emphasis [that] coal — not to mention oil and natural gas — could have on our energy system, this would be a disaster for climate. Bottom line is that we can no longer rely on policies that could be adopted to address concerns about energy security, looking to climate policy as a silent secondary beneficiary. We must now confront the climate issue directly. Clearly many in the body politic are reluctant to do so.

    GAZETTE: And the electricity supply has gotten cleaner, hasn’t it? But not because of climate change efforts?

    McELROY: Not because of climate change, but for economic reasons, largely. If you’re a utility and you’re able to vary the mix of generation options you can tap to produce electricity, your primary choice is likely to be between coal and natural gas. Old coal-fired power plants are very inefficient compared to new gas-fired power plants. The efficiency to turn the energy of coal into electricity in some of the older plants is as low as 20 percent. If you’re just worrying about efficiency, if you have the opportunity to turn off that inefficient coal plant and switch to a gas system and additionally save money [since gas is cheaper than coal], you’re going to do it. The choice is economically driven and the consumers are actually benefiting.

    GAZETTE: In your vision for the future, you emphasize that more electricity usage could be part of the solution. Clearly, electricity is already a big part of our energy picture; why should it be even larger?

    McELROY: Dealing with CO2 emissions from the transportation sector is extremely difficult if the transportation sector is fueled with liquid fossil fuels. You can’t capture CO2 from the tailpipe of every vehicle on the road — 260 million cars in the U.S. At the same time, there’s another a good reason to want to use electricity more in this application. If you drive your car with gasoline, the fraction of the energy in the gasoline that turns the wheels of your car may be as low as about 20 percent. If you drive your car with electricity, the fraction of electricity that turns the wheels could be as high as 95 percent. So, on an efficiency basis, electricity is better. As I discussed in the book, if I had to pay the retail price for electricity here in Cambridge, 19.8 cents a kilowatt hour when I was writing the relevant chapter, the equivalent gasoline price would be as low as $1.46 a gallon, as low as 67 cents a gallon in Washington state where electricity prices average about 9 cents per kilowatt-hour. So on a cost basis, it’s a good thing to do. Then, in addition, air quality would improve if we switched to driving electrically, so long as the electricity was produced from a nonpolluting source. The climate issue would be the obvious beneficiary.

    GAZETTE: You go chapter by chapter on possible fuels, and settle on wind and solar as the cleanest and most likely sources to power a future clean electricity grid. What are their drawbacks and can those be addressed?

    McELROY: The economics of wind in the United States is actually quite favorable. You can produce electricity for about 5 cents a kilowatt-hour with wind at present. So it’s competitive. The really serious drawback is that the wind is strongest in winter and our demand for electricity is highest in summer. The wind is also generally stronger at night than it is during the day and our big demand is during the day. And wind doesn’t blow all the time. So we need to find some way to deal with that particular issue.

    There are a number of possible strategies. You could integrate the electrical system over a large part of the country — so if wind is blowing in one place and not in another, by combining outputs you could reduce the net variability. If you had the opportunity to store electricity, that could minimize the problem also. So putting an emphasis on storage systems is a good thing to do. There’s important work going on here at Harvard by Mike Aziz and Roy Gordon on the flow battery idea. It’s something that might actually scale up as a utility scale opportunity to store electricity.

    I am enthusiastic also about the idea of taking advantage of the distributed storage available potentially in the batteries of large numbers of electrically propelled vehicles. I discuss this idea at some length in the book. You could imagine charging your car at night when prices of electricity are low and then selling power back to the grid during the day when prices are high, assuming you don’t need to drive at that time. This could represent a win-win strategy.

    You would still have the issue of summer demand for electricity when wind conditions will be less favorable. That’s where solar comes in. Solar, however, to this point, is still more expensive than wind. Despite this, solar is doing quite well in the U.S. We have a house on Cape Cod and five years ago or so we installed PV cells on the roof. We did this by making a deal with a particular company, Solar City, one in which they actually own the solar cells. They sized the solar cells to meet our projected historical annual demand for electricity. They gave us a deal where we have a fixed price for electricity for 20 years at half of what we were paying previously. How do they manage to do that? Turns out the retail cost for electricity on Cape Cod is very high. It’s very high because the delivery cost is high. The retail price is about 26 cents a kilowatt-hour, more than half of which is for delivery. So they’re giving us a deal at 13 cents per kilowatt-hour.

    There are requirements in almost all of the states now that some fraction of the electricity has to be renewable. If the utilities are not able to meet that requirement from their own resources, which generally they’re not, then they have to buy it. So the Solar Cities of the world are auctioning their renewable energy for incorporation in the grid. If New England Electric is looking for a certain amount of electricity from a renewable source, then Solar City can supply this by packaging sources from large numbers of houses under their control.

    The other thing that’s happening in the U.S. is that meters in many states are allowed to run in reverse. We’re not typically present on Cape Cod in winter. The sun is still shining most of the time and the house continues to produce electricity. Solar City is selling this electricity to the grid at the retail price. Our meter is running in reverse. So, for a lot of reasons, solar has done very well.

    GAZETTE: You say that one of the top priorities for this country should be upgrading the transmission grid. I think a lot of people, when thinking about climate change, think wind farm, solar farm, but not transmission grid. Why do we need that?

    McELROY: Think of the role played more than 100 years ago by Thomas Alva Edison. Edison was an incredible inventor. He was also a very smart guy and he built the first electricity-generating system in Manhattan. Then Westinghouse came along and suddenly we began to see electricity generated in central facilities and distributed more widely to local customers. We’ve built our electrical system in a piecemeal way. We didn’t say, “What’s the best national electricity system?” If we had done that, we would have had an interconnected national electricity system.

    The U.S. has three electricity systems: East Coast grid, West Coast grid, and Texas. It’s very difficult to move electricity across those boundaries. At a minimum, we should invest to interconnect the boundaries. That’s a no-brainer and it would not be very expensive. I like to think about being able to move electricity efficiently over several thousand miles, coast to coast, border to border. We have wonderful wind resources in the middle of the country. The key location to produce electricity from the sun is in the southwest, where we have great solar conditions. The ideal would be to bring both those sources to where the markets are, on the East Coast and West Coast and in major cities like Chicago. But if you’re going to serve those markets you have to be able to deliver.

    In addition, the demand for electricity peaks in the morning and peaks in the evening: when people get up and when they come back from work. If we had a system that was interconnected from California to Massachusetts, at a minimum we’d take advantage of the three-hour time shift to smooth out the peaks in demand.

    What are the obstacles? The obstacles are largely political — the fact that you have to bring power across state boundaries, and you may have to go across individuals’ property. The federal government has the authority to overrule objections if it’s declared to be in the national interest or if it’s in effect a matter of national security. That’s largely why we have a reasonably efficient natural gas distribution system. It could be done for electricity also if we had the will to do it.

    If you really make a commitment to developing this electrical infrastructure, you’re going to have to employ lots of people. So this would be good for the economy. My vision would be one in which we invest in community colleges that train people for those jobs. These are going to be good-paying jobs that can’t be exported.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 8:46 am on August 25, 2016 Permalink | Reply
    Tags: , , Harvard, , Necrostatin-1 restored the myelin sheath and stopped axonal damage, RIPK1 as a key regulator of inflammation and cell death   

    From Harvard: “Harvard researchers pinpoint enzyme that triggers cell demise in ALS” 

    Harvard University

    Harvard University

    August 24, 2016
    Ekaterina Pesheva

    1
    Therapies already in development aim to block the activity of a particular enzyme in order to halt the stripping of axons and prevent neuronal dysfunction in people with amyotrophic lateral sclerosis, or ALS. Credit: iStock

    Scientists from Harvard Medical School (HMS) have identified a key instigator of nerve cell damage in people with amyotrophic lateral sclerosis, or ALS, a progressive and incurable neurodegenerative disorder.

    Researchers say the findings of their study, published Aug. 5 in the journal Science, may lead to new therapies to halt the progression of the uniformly fatal disease that affects more than 30,000 Americans. One such treatment is already under development for testing in humans after the current study showed it stopped nerve cell damage in mice with ALS.

    The onset of ALS, also known as Lou Gehrig’s disease, is marked by the gradual degradation and eventual death of neuronal axons, the slender projections on nerve cells that transmit signals from one cell to the next. The HMS study reveals that the aberrant behavior of an enzyme called RIPK1 damages neuronal axons by disrupting the production of myelin, the soft, gel-like substance that envelopes axons to insulate them from injury.

    “Our study not only elucidates the mechanism of axonal injury and death but also identifies a possible protective strategy to counter it by inhibiting the activity of RIPK1,” said the study’s senior investigator, Junying Yuan, the Elizabeth D. Hay Professor of Cell Biology at HMS.

    The new findings come on the heels of a series of pivotal discoveries Yuan and colleagues made over the last decade, which revealed RIPK1 as a key regulator of inflammation and cell death. But until now, scientists were unaware of its role in axonal demise and ALS. Experiments conducted in mice and in human ALS cells reveal that when RIPK1 is out of control, it can spark axonal damage by setting off a chemical chain reaction that culminates in stripping the protective myelin off axons and triggering axonal degeneration — the hallmark of ALS. RIPK1, the researchers found, inflicts damage by directly attacking the body’s myelin production plants — nerve cells known as oligodendrocytes, which secrete the soft substance, rich in fat and protein, that wraps around axons to support their function and shield them from damage. Building on previous work from Yuan’s lab showing that RIPK1’s activity could be blocked by a chemical called necrostatin-1, the research team tested how ALS cells in lab dishes would respond to the same treatment. Indeed, necrostatin-1 tamed the activity of RIPK1 in cells of mice genetically altered to develop ALS.

    In a final set of experiments, the researchers used necrostatin-1 to treat mice with axonal damage and hind leg weakness, a telltale sign of axonal demise similar to the muscle weakness that occurs in the early stages of ALS in humans. Necrostatin-1 not only restored the myelin sheath and stopped axonal damage, but also prevented limb weakness in animals treated with it.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
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