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News Article | April 25, 2016
Site: www.rdmag.com

Winter sports areas around the world employ some microscopic help when Mother Nature is being finicky with snow production. Pseudomonas syringae, an ice-active bacterium, boasts a high-ice nucleating ability. An inactive form of the bacterium is used in the commercial snow inducer product—Snomax. Publishing in Science Advances, researchers from the Max Planck Institutes for Chemistry and for Polymer Research zeroed in on the molecular mechanism that gives this bacteria the ability to form ice. “With their ability to induce ice formation at temperatures just below the ice melting point, bacteria such as Pseudomonas syringae attack plants through frost damage using specialized ice-nucleating proteins,” the researchers wrote. “Besides the impact on agriculture and microbial ecology, airborne P. syringae can affect atmospheric glaciation processes, with consequence for cloud evolution, precipitation, and climate.” Using a technique called sum frequency generation spectroscopy, the researchers glimpsed how the bacteria exerted influence over a nearby water network. “The interactions of specific amino-acid sequences of the protein molecules generate water domains with increased order and stronger hydrogen bonds,” according to the Max Planck Institutes. “Additionally, the proteins remove thermal energy from the water into the bacteria. As a result, water molecules can aggregate into ice crystals more easily.” The bacterium is capable of inducing freezing in water droplets at negative 2 C. Mineral dust, or atmospheric aerosols, trigger ice formation only when below negative 15 C. Tobias Weidner, one of the study’s authors, told Popular Mechanics that pure-water droplets in the atmosphere sometimes won’t freeze until reaching negative 40 C. According to The Verge, P. syringae has been found in snowfall around the world. The bacterium’s properties have led scientists to believe they’re integral to cloud formation and rainfall. It is believed the bacteria are blown from the ground to the sky. However, their role in causing precipitation has never been established, Russ Schnell, of the National Oceanic and Atmospheric Administration, told the media outlet. The researchers said they hope to replicate the bacterial ice nucleating mechanism, and use it for other applications. Establish your company as a technology leader! For more than 50 years, the R&D 100 Awards have showcased new products of technological significance. You can join this exclusive community! Learn more.


News Article | March 8, 2016
Site: phys.org

Ordinarily, of course a fly does not shimmer green. Here, researchers - with the help of genetic tricks -  succeeded in making a muscle protein glow, which they can then locate under a fluorescence microscope. Credit: MPI for Biochemistry The human genome codes for more than 20,000 different proteins, however the molecular role for many of these proteins is not known. As most proteins are conserved from fly to humans, understanding the molecular role of a protein in flies can be the first step towards a therapy against a variety of human diseases that are often caused by aberrantly behaving proteins. A consortium of scientists from the Max Planck Institutes of Biochemistry in Martinsried and Molecular Cell Biology and Genetics in Dresden, and the National Centre for Biological Sciences (NCBS) in Bangalore have now reached a milestone towards understanding the function of these proteins by using the fruit fly. The human body is built by many hundreds of different cell types; each one has a very particular function in the body. Red blood cells transport oxygen, nerve cells exchange signals and muscle cells generate mechanical forces. The majority of cellular functions is produced by the action of 20,000-25,000 proteins coded in the human genome. Although sequencing and annotation of human genome were completed in 2004, to date the function of many thousands of these proteins is still mysterious. It is often unknown, which cell types produce which proteins, and particularly where these proteins are located within the cells. Are they in the nucleus or within membranous vesicles, are they within neuronal dendrites or synapses, or are they within the contractile machinery of muscles? Protein localisation is an important piece of information, as it is the first step towards identifying a molecular function for a protein. Unravelling the function of a protein is often started in simpler model organisms such as worms or flies. Like humans, fruit flies have muscles, neurons, oocytes, sperm and many other essential cells types. The fly genome contains about 13,000 protein coding genes, which are responsible for building and maintaining all fly organs. Importantly, many of these proteins are very similar to the human proteins, thus studying a protein in flies will teach us about its role in the human body. To boost these protein studies onto a systematic level, groups headed by Frank Schnorrer at the Max-Planck Institute in Martinsried, Pavel Tomancak and Mihail Sarov at the Max-Planck Institute in Dresden and K VijayRaghavan at the NCBS in Bangalore have generated a large resource for visualizing proteins in Drosophila melanogaster. By using modern molecular biology tricks, the scientists have attached a green fluorescent protein (GFP) tag to 10,000 of these protein coding genes in the test tube. Each tagged gene can then be re-introduced into the fly genome as a 'transgene', creating the fly 'TransgeneOme'. "Together, we thus far generated 880 different fly strains, each of which expresses a different fluorescently tagged protein", explains Frank Schnorrer, "these proteins can then be observed by fluorescent video microscopy in various cell types of the developing fruit fly". For more than 200 proteins, the scientists documented where they are located during fly development, starting with an oocyte that develops into an embryo and finally into the mature fly. The Tomancak group used the so-called light sheet microscopy to film how proteins emerge in cells of the embryo during the first day of its development. The Schnorrer group used this resource to study the localisation of proteins in muscles. As in human skeletal muscles, fly muscles contain complex mini-machines called sarcomeres that produce the mechanical forces enabling animal movements. "We have looked so far at only 200 of these transgenic lines. The future challenge lies in systematically imaging the localization of these proteins in many fly tissues and this is best achieved by involving the powerful Drosophila research community" predicts Pavel Tomancak. The resource will have enormous impact on the understanding of not only fly biology but also on the understanding of protein function in the different human cell types." More information: Mihail Sarov et al. A genome-wide resource for the analysis of protein localisation in , eLife (2016). DOI: 10.7554/eLife.12068


News Article | November 16, 2016
Site: www.nature.com

Life can get in the way of science, forcing PhD students to take time out from the pursuit of knowledge and the lab. It can be a tough call for students to make. Immersed in their work with no assurances of a great job, driven to scour the literature to stay current and primed to worry about competition and impressing their advisers, many PhD students think that academic success is everything. For them, nothing comes before their studies and research programme. Breaks are risky — there is no way to ensure a smooth return to studies, funding and the bench. University policies governing gap time vary across nations, regions and institutions, and maintaining funding and research continuity can pose hurdles. Attitudes towards time off also differ widely. Many faculty members and potential future employers look askance at a doctoral student's decision to step aside, even for a brief period. Your capacity to put your PhD programme on hold will depend largely on your field, your institution and your advisers. In general, you can take a break when you need it, as long as you are prepared for the consequences — particularly if you aim to pursue an academic career. The decision could affect your reputation, publishing record and ability to stay current with your research programme. But with careful planning, there are ways to soften the blow (see 'How to take a successful break'). Few statistics exist on how often, for how long or why PhD students take time off from their studies. In the United States, neither the National Science Foundation nor the Council of Graduate Schools tracks leaves of absence or can point to a central source for such data. Some individual institutions provide estimates of how many PhD students have taken breaks each year. Heather Amos, a spokesperson for the University of British Columbia in Vancouver, Canada, says that about 50 PhD students out of nearly 4,000 across all disciplines, or about 1.25%, took a leave of absence in 2015. Martin Grund, spokesperson for the Max Planck Institutes' graduate-student organization, PhDnet, says that his group doesn't track leaves of absence. But, he says, internal surveys show that 7% of doctoral students at the institutes in 2012 were parents, and so had probably taken parental leave at some point. Some funding agencies allow for certain interruptions of study, including care for children and elderly people, professional development and other life needs. Some universities permit students to retain access to campus services while on leave for a variety of reasons; others have no defined policy. Anecdotally, it seems that few PhD students so much as think about a pause in their programme. “I think most don't even consider it,” says Heather Buschman, who earned a PhD in molecular pathology from the University of California, San Diego, School of Medicine after taking six months off for a US National Cancer Institute communications internship in 2006. “They think, 'I could never do that'. People are on such a focused trajectory and see any wavering as a negative.” There is a great deal of external and internal pressure to race to the finish, agrees Gareth O'Neill, a PhD candidate in linguistics at Leiden University in the Netherlands. “Doing a PhD is a relatively focused and driven occupation — once started, you just want to finish it,” he says. As a board member of the PhD Candidates' Network of the Netherlands, O'Neill is involved with an initiative called the Professional PhD Program, which helps to place PhD students who seek work experience outside academia. O'Neill says that the programme rarely receives applications from students who feel they need to stay at the bench throughout their doctoral studies, but that those who do apply sometimes experience pressure from supervisors to finish their PhD sooner. That pressure, he adds, is misguided or inapplicable — particularly from mid- or late-career scholars, who don't know or who don't want to admit how hard it is for new PhD students to remain in academia now. “We hope to bring about a shift of mindset,” he says. Still, when the need for a hiatus arises, some don't hesitate to take it — and then sail through their leave and back. Earlier this year, Anna Miller earned a PhD in parks, recreation and tourism management from North Carolina State University (NCSU) in Raleigh. She says that she never questioned her decision to leave her research behind for half a year, when her Brazilian fiancé was offered a postdoctoral appointment in Portugal. The travails of a long-distance relationship had become burdensome, and she wanted to join him abroad. “Academically, I was getting a bit burnt out, but it was really the strain on my personal life that was the problem,” she says. “If I was going to stay in the programme, I needed to deal with the personal part of my life.” Her adviser was concerned that she might not come back, and Miller herself says that she left for Portugal knowing that might be true. But in Lisbon, she found herself drawn to nearby parks, and started studying how they were managed, just for fun. “It was a refreshing way to look at the same questions from a different perspective and reaffirm my desire to study this subject,” she says. “I came back with new energy for being a full-time student.” Re-entry turned out to be easy. To get approval for a leave of absence, Miller and her advisers had already agreed on a formal plan for her return, charting out how she would later complete course work, research and exams. They had also predetermined how Miller's funding, which was suspended while she was away, would be reinstated. Everything unfolded as planned — and Miller became treasurer and then co-president of her department's graduate-student association. She also began to mentor other students and to organize career panels and other programmes. Three years on, Miller and her fiancé have since married, and she is now a resident lecturer at the School for Field Studies Center for Marine Resource Studies in the Turks and Caicos Islands. She teaches undergraduates who are studying abroad. “I can't think of any negatives of taking the time off,” she says. Others also report a positive experience. “Ideally, I'd say don't take time off, but if you do, don't judge yourself harshly,” says Jen O'Keefe, a geologist and science-education researcher at Morehead State University in Kentucky. She took a pause from her PhD studies in 2002, after a working relationship with an adviser fell apart. Ultimately, she devised a new plan that combined part-time work on her doctorate with a full-time teaching schedule. Looking back, she thinks that her research career benefited from the five-month break, which enabled her to refocus her work towards palaeoecology and curriculum and instruction, as well as a variety of other pursuits that she loves. “Everything from fly-ash geochemistry to honey studies to sinkholes,” she says. “No two PhD situations are the same. You have to do what's right for you.” Some think that their field of study smoothed the way. Benedikt Herwerth, who studies theoretical quantum physics at the Max Planck Institute of Quantum Optics in Garching, Germany, says that he had little trouble setting up two stints of paternity leave, for a total of seven months, after the birth of his daughter in February. He says that Germany's generous approach towards parental leave helped, but that his field of study might also have facilitated the interruption. “I'm not doing experiments,” he says. “It might be an advantage.” Even when there are no obstacles to taking time off, trouble might arise that complicates a student's return. Eleanor Harding, a doctoral candidate at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, has taken two breaks from her PhD research on how the brain processes music and language. The first was in 2011, when her mother died. Harding took several months off. “I lost my edge for quite a while,” she says. “But my adviser encouraged me to keep going.” Harding returned to work later that year and expected to earn her degree in 2013 — until an experiment fell through, which caused delays, and pregnancy complications rendered her unable to work. In May 2014, after her daughter was born, Harding returned to her research, but she found that she could not afford enough childcare to resume her studies full-time. In addition, while she had been out, other researchers had published work in her area, so she had to redirect her research to examine a narrower question that would respond to the other scientists' work. “Now, unfortunately, I'm in the middle of the pack instead of at the front,” she says. “I can't say I was the first.” A gap of just one year can put a PhD candidate behind when it comes to mastery of important technological advances, warns Kim First, president and chief executive of the recruiting firm Agency Worldwide in Encino, California. As a headhunter who searches for PhD graduates for jobs in biotechnology and pharmaceutical companies, she says that she encounters few candidates who have interrupted their doctoral programme. “The way technology is changing, taking a break can become difficult,” she says. “How do you stay cutting edge?” Other recruiters say that taking time away to have children or for other life events can hurt a researcher's scientific reputation, and that students should find ways to incorporate those obligations into their PhD programme without putting their research on pause. Some think that the stigma might be worse for women. Justin Schwartz, head of the materials science and engineering department at NCSU, has helped students to organize leaves of absence. When it comes to parental leave, he says, women are more likely than men to take the time off — but those who do are often terrified (sadly, with some reason, he notes) that faculty members will think that they lack the drive to be the best and will extrapolate that women aren't suited to doing science. But whether female or male, most students experience one clear consequence after taking the break: they lose momentum. Harding says that although there was a benefit to delaying her dissertation — a competing paper helped her to solve a problem in her data — she now has few job leads near her husband's medical residency in the Netherlands, and attributes that to having lost potential publications and chances to attend more conferences. “Your worth is based on quantitative measures like an impact factor,” she says. “They want people with publications. Life doesn't always cooperate.” Harding is now networking locally — getting involved, for instance, with a organization in the region that funds research into Parkinson's disease. O'Keefe wishes that the harsh judgement weren't there, but says that it seems specific to academia. “People feel badly and a lot of scientists out there judge them harshly,” she says. “There's a lot of, 'If you had to take time off, you're not really good enough to finish'.” She says that many early-career scientists she knows who interrupted their PhD programmes eschewed academic research in the end, and instead, accepted positions in industry or teaching. Now in her early 40s and a mother, she says that she wouldn't have done anything differently, and looks forward to expanding her research. “I was on the fast track and I was moving too fast,” she says. “A lot of good comes from taking a break and reassessing your priorities. A year off is sometimes the best thing you can do. The big message is, it's OK and you're not alone and you can go on to be what you want to be.”


News Article | November 10, 2016
Site: www.eurekalert.org

What would happen if an electric current no longer flowed, but trickled instead? This was the question investigated by researchers working with Christian Ast at the Max Planck Institute for Solid State Research. Their investigation involved cooling their scanning tunnelling microscope down to a fifteen thousandth of a degree above absolute zero. At these extremely low temperatures, the electrons reveal their quantum nature. The electric current is therefore a granular medium, consisting of individual particles. The electrons trickle through a conductor like grains of sand in an hourglass, a phenomenon that can be explained with the aid of quantum electrodynamics. Flowing water from a tap feels like a homogeneous medium -- it is impossible to distinguish between the individual water molecules. Exactly the same thing is true about electric current. So many electrons flow in a conventional cable that the current appears to be homogeneous. Although it is not possible to distinguish individual electrons, quantum mechanics says they should exist. So how do they behave? Under which conditions does the current not flow like water through a tap, but rather trickles like sand in an hourglass? The hourglass analogy is very appropriate for the scanning tunnelling microscope, where a thin, pointed tip scans across the surface of a sample without actually touching it. A tiny current flows nevertheless, as there is a slight probability that electrons "tunnel" from the pointed tip into the sample. This tunnelling current is an exponential function of the separation, which is why the pointed tip is located only a few Ångström (a ten millionth of a millimetre) above the sample. Minute variations in the tunnelling current thus allow researchers to resolve individual atoms and atomic structures on surfaces and investigate their electronic structure. Scanning tunnelling microscopes are therefore some of the most versatile and sensitive detectors in the whole of solid state physics. Even under these extreme conditions - a tiny current of less than one billionth of the current that flows through a 100-watt light bulb - billions of electrons per second still flow. This is too many to discern individual electrons. The temperature was down at around a fifteen thousandth of a degree above absolute zero (i.e. at minus 273.135°C or 15 mK) before the scientists saw that the electric current consists of individual electrons. At this low temperature, very fine structures, which the researchers had not expected, appear in the spectrum. "We could explain these new structures only by assuming that the tunnelling current is a granular medium and no longer homogeneous," says Ast, who heads the group working with the scanning tunnelling microscope. This is thus the first time that the full quantum nature of electronic transport in the scanning tunnelling microscope has shown itself. The electric charge must therefore be quantized as well if this quantum mechanical phenomenon is to be fully explained. "The theory on which this is based was developed back at the beginning of the 1990s. Now that conceptual and practical issues relating to its application to scanning tunnelling microscopes have been solved, it is nice to see how consistently theory and experiment fit together," says Joachim Ankerhold from the University of Ulm, who contributed the theoretical basis. In addition to a detailed theory, experiments of this type require an adapted laboratory environment which reduces external disturbances to a large extent. Since the end of 2012, a new precision laboratory has been in operation on the campus of the Max Planck Institutes in Stuttgart; it provides an almost disturbance-free laboratory environment for highly sensitive experiments such as the mK scanning tunnelling microscope. The instrument is located in the precision laboratory in a box equipped with both acoustic and electromagnetic shielding on a vibration-decoupled concrete base. "We want to use it to venture into new, unknown territory - which we did very successfully with this experiment," says Klaus Kern, Director at the Max Planck Institute for Solid State Research. Electrons have already demonstrated their quantum nature. As they are transported through quantum dots, for example, the current flow is specifically blocked so that the electrons appear individually. This effect became evident in the scanning tunnelling microscope simply by cooling it to extremely low temperatures, however. "The tunnel effect has definitely reached the quantum limit here," says team member Berthold Jäck. The researchers do not want to view this as a limitation, however. "These extremely low temperatures open up an unexpected richness of detail which allows us to understand superconductivity and light-matter interactions much better," says Christian Ast.


News Article | November 8, 2016
Site: phys.org

Keeping a close eye on everything: Christian Ast checks the connections of the scanning tunneling microscope (top). Researchers in the Nanoscale Science Department conduct their experiments in this instrument at lowest temperatures of a fifteen thousandth of a degree above absolute zero. The principle is always the same (bottom): A tunneling current (illustrated by the transparent bar) flows between an ultrafine tip and the sample, providing information about the properties of the sample. At these low temperatures the tunneling current reveals all of its quantum properties. Credit: Tom Pingel (top), MPI for Solid State Research (bottom) What would happen if an electric current no longer flowed, but trickled instead? This was the question investigated by researchers working with Christian Ast at the Max Planck Institute for Solid State Research. Their investigation involved cooling their scanning tunnelling microscope down to a fifteen thousandth of a degree above absolute zero. At these extremely low temperatures, the electrons reveal their quantum nature. The electric current is therefore a granular medium, consisting of individual particles. The electrons trickle through a conductor like grains of sand in an hourglass, a phenomenon that can be explained with the aid of quantum electrodynamics. Flowing water from a tap feels like a homogeneous medium - it is impossible to distinguish between the individual water molecules. Exactly the same thing is true about electric current. So many electrons flow in a conventional cable that the current appears to be homogeneous. Although it is not possible to distinguish individual electrons, quantum mechanics says they should exist. So how do they behave? Under which conditions does the current not flow like water through a tap, but rather trickles like sand in an hourglass? The hourglass analogy is very appropriate for the scanning tunnelling microscope, where a thin, pointed tip scans across the surface of a sample without actually touching it. A tiny current flows nevertheless, as there is a slight probability that electrons "tunnel" from the pointed tip into the sample. This tunnelling current is an exponential function of the separation, which is why the pointed tip is located only a few Ångström (a ten millionth of a millimetre) above the sample. Minute variations in the tunnelling current thus allow researchers to resolve individual atoms and atomic structures on surfaces and investigate their electronic structure. Scanning tunnelling microscopes are therefore some of the most versatile and sensitive detectors in the whole of solid state physics. Even under these extreme conditions – a tiny current of less than one billionth of the current that flows through a 100-watt light bulb – billions of electrons per second still flow. This is too many to discern individual electrons. The temperature was down at around a fifteen thousandth of a degree above absolute zero (i.e. at minus 273.135°C or 15 mK) before the scientists saw that the electric current consists of individual electrons. At this low temperature, very fine structures, which the researchers had not expected, appear in the spectrum. "We could explain these new structures only by assuming that the tunnelling current is a granular medium and no longer homogeneous," says Ast, who heads the group working with the scanning tunnelling microscope. This is thus the first time that the full quantum nature of electronic transport in the scanning tunnelling microscope has shown itself. The electric charge must therefore be quantized as well if this quantum mechanical phenomenon is to be fully explained. "The theory on which this is based was developed back at the beginning of the 1990s. Now that conceptual and practical issues relating to its application to scanning tunnelling microscopes have been solved, it is nice to see how consistently theory and experiment fit together," says Joachim Ankerhold from the University of Ulm, who contributed the theoretical basis. In addition to a detailed theory, experiments of this type require an adapted laboratory environment which reduces external disturbances to a large extent. Since the end of 2012, a new precision laboratory has been in operation on the campus of the Max Planck Institutes in Stuttgart; it provides an almost disturbance-free laboratory environment for highly sensitive experiments such as the mK scanning tunnelling microscope. The instrument is located in the precision laboratory in a box equipped with both acoustic and electromagnetic shielding on a vibration-decoupled concrete base. "We want to use it to venture into new, unknown territory – which we did very successfully with this experiment," says Klaus Kern, Director at the Max Planck Institute for Solid State Research. Electrons have already demonstrated their quantum nature. As they are transported through quantum dots, for example, the current flow is specifically blocked so that the electrons appear individually. This effect became evident in the scanning tunnelling microscope simply by cooling it to extremely low temperatures, however. "The tunnel effect has definitely reached the quantum limit here," says team member Berthold Jäck. The researchers do not want to view this as a limitation, however. "These extremely low temperatures open up an unexpected richness of detail which allows us to understand superconductivity and light-matter interactions much better," says Christian Ast. Explore further: Scientists visualise quantum behaviour of hot electrons for first time More information: Christian R. Ast et al. Sensing the quantum limit in scanning tunnelling spectroscopy, Nature Communications (2016). DOI: 10.1038/ncomms13009


News Article | November 10, 2016
Site: www.sciencedaily.com

What would happen if an electric current no longer flowed, but trickled instead? This was the question investigated by researchers working with Christian Ast at the Max Planck Institute for Solid State Research. Their investigation involved cooling their scanning tunneling microscope down to a fifteen thousandth of a degree above absolute zero. At these extremely low temperatures, the electrons reveal their quantum nature. The electric current is therefore a granular medium, consisting of individual particles. The electrons trickle through a conductor like grains of sand in an hourglass, a phenomenon that can be explained with the aid of quantum electrodynamics. Flowing water from a tap feels like a homogeneous medium -- it is impossible to distinguish between the individual water molecules. Exactly the same thing is true about electric current. So many electrons flow in a conventional cable that the current appears to be homogeneous. Although it is not possible to distinguish individual electrons, quantum mechanics says they should exist. So how do they behave? Under which conditions does the current not flow like water through a tap, but rather trickles like sand in an hourglass? The hourglass analogy is very appropriate for the scanning tunneling microscope, where a thin, pointed tip scans across the surface of a sample without actually touching it. A tiny current flows nevertheless, as there is a slight probability that electrons "tunnel" from the pointed tip into the sample. This tunneling current is an exponential function of the separation, which is why the pointed tip is located only a few Ångström (a ten millionth of a millimetre) above the sample. Minute variations in the tunneling current thus allow researchers to resolve individual atoms and atomic structures on surfaces and investigate their electronic structure. Scanning tunneling microscopes are therefore some of the most versatile and sensitive detectors in the whole of solid state physics. Even under these extreme conditions -- a tiny current of less than one billionth of the current that flows through a 100-watt light bulb -- billions of electrons per second still flow. This is too many to discern individual electrons. The temperature was down at around a fifteen thousandth of a degree above absolute zero (i.e. at minus 273.135°C or 15 mK) before the scientists saw that the electric current consists of individual electrons. At this low temperature, very fine structures, which the researchers had not expected, appear in the spectrum. "We could explain these new structures only by assuming that the tunneling current is a granular medium and no longer homogeneous," says Ast, who heads the group working with the scanning tunneling microscope. This is thus the first time that the full quantum nature of electronic transport in the scanning tunneling microscope has shown itself. The electric charge must therefore be quantized as well if this quantum mechanical phenomenon is to be fully explained. "The theory on which this is based was developed back at the beginning of the 1990s. Now that conceptual and practical issues relating to its application to scanning tunneling microscopes have been solved, it is nice to see how consistently theory and experiment fit together," says Joachim Ankerhold from the University of Ulm, who contributed the theoretical basis. In addition to a detailed theory, experiments of this type require an adapted laboratory environment which reduces external disturbances to a large extent. Since the end of 2012, a new precision laboratory has been in operation on the campus of the Max Planck Institutes in Stuttgart; it provides an almost disturbance-free laboratory environment for highly sensitive experiments such as the mK scanning tunneling microscope. The instrument is located in the precision laboratory in a box equipped with both acoustic and electromagnetic shielding on a vibration-decoupled concrete base. "We want to use it to venture into new, unknown territory -- which we did very successfully with this experiment," says Klaus Kern, Director at the Max Planck Institute for Solid State Research. Electrons have already demonstrated their quantum nature. As they are transported through quantum dots, for example, the current flow is specifically blocked so that the electrons appear individually. This effect became evident in the scanning tunneling microscope simply by cooling it to extremely low temperatures, however. "The tunnel effect has definitely reached the quantum limit here," says team member Berthold Jäck. The researchers do not want to view this as a limitation, however. "These extremely low temperatures open up an unexpected richness of detail which allows us to understand superconductivity and light-matter interactions much better," says Christian Ast.


The world's largest digital sky survey data have been released. The Dec. 19 release of the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) project digitally surveyed and cataloged three-fourths of the night sky and captured information about 3 billion stars, galaxies, and other spatial objects. Participated by astronomers from the Max Planck Institutes for Astronomy, Heidelberg and Garching's Extraterrestrial Physics institute among others, the vast data of the digital sky survey comprises 3 billion sources including stars and galaxies. It must be mentioned that the survey paid extreme attention to the Milky Way plane and disk. This was an area shunned in most surveys because of the complexity involved in mapping the dusty regions. The project started in May 2010 as the first Panoramic Survey Telescope & Rapid Response System digital mapping of the sky in visible and near infrared light. "For the past three years, we put much effort into checking the quality of the data and defining the most useful structure for the catalog," explained Roberto Saglia, who represented the sky survey from Max Planck Institute for Extraterrestrial Physics. The survey scanned the sky in five filters until 2014 and two years were spent on cataloging the data in such a way the astrophysics community must benefit immensely. Hans-Walter Rix, director of the Galaxies and Cosmology department of MPIA noted that Pan-STARRS survey is unique because it combines imaging depth and colors in highlighting distant quasars which are the earliest evidence of giant black holes having emerged at the centers of galaxies. The roll out is in two steps. The first phase pertaining to "Static Sky" analyses individual epochs with every object assigned an average value in terms of brightness, position, and colors. Objects also get a stack image in the observed colors. Galaxies are provided with information on brightness, aperture sizes and viewing conditions. In part two of data, to be released in 2017, information on individual epochs will allow people to access individual images in each observation run. Reflecting the benefits for astronomers, Thomas Henning, director, Planet and Star Formation Department at MPIA said the data offers a better characterization of low-mass star formation in stellar clusters. "Based on Pan-Starrs, researchers are able to measure distances, motions and special characteristics such as the multiplicity fraction of all nearby stars, brown dwarfs, and of stellar remnants like, for example, white dwarfs," added Henning. In a nut shell, the gains of the Pan-STARRS project can be summarized as successfully tracking fast-moving objects in the sky with the use of the 6-foot telescope at the top of the Haleakala volcano in Hawaii's Maui. With meticulous details backed by images of the sky in every 30 seconds, expectations are high that the map can offer new insights into dark energy as well. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | November 25, 2016
Site: news.europawire.eu

LMU‘s Graduate School of Systemic Neurosciences, which is now 10 years old, focuses on a single issue: How does the brain work? Doctoral students from all over the world are seeking answers to this immensely complicated question. MÜNCHEN, 25-Nov-2016 — /EuropaWire/ — The Mongolian gerbil must localize sounds in double-quick time, for its very survival depends on its ability to process acoustic information. Acoustic signals are picked up by both ears, but they reach the ipsilateral ear (the one closer to the sound source) a few microseconds earlier than the contralateral organ. Moreover, activation of the sensory neurons in the ipsilateral ear results in the inhibition of their counterparts in the contralateral ear. The Australian neurobiologist Kiri Couchman is seeking the basis for this mechanism by probing the operation of the synapses, the junctional structures that determine whether transmission of the nerve impulse to the next cell in the circuit is promoted or prevented. She has already determined that inhibition/activation of a very small number of nerve fibers is sufficient to provoke strong inhibition/activation of the post-synaptic neuron in the circuit. Couchman did her doctoral research as a member of the Graduate School of Systemic Neurosciences (GSN-LMU), which is 10 years old this month. The investigation of brain function requires an interdisciplinary approach, and the graduate students and their mentors in the GSN come from a variety of backgrounds, ranging from philosophy to biochemistry and biophysics. Neurobiologist Couchman (32) was particularly struck by the emphasis placed on interdisciplinarity at the GSN, which is perhaps not surprising when one considers that she herself studied Philosophy. “In our regular lectures on the various disciplines, we gained fascinating insights and became acquainted with the intriguing issues involved. We learned about questions and fields that we would never have been exposed to if we had focused solely on our own specific area of interest.” She also remembers being very impressed by the infrastructure available in Munich. Having spent 4 years at the GSN and earned her doctorate there, she now works at the Institut Pasteur in Paris. “The GSN holds the whole network together“ The Bavarian capital is a force to be reckoned with in the neurosciences, and is home to an array of institutions — including the GSN — that is unique in Germany. These include the Bernstein Center for Computational Neurosciences Munich, the Max Planck Institutes for Neurobiology, Ornithology and Psychiatry, several Collaborative Research Centers in the field and the Helmholtz Zentrum München. All in all, this network offers an exceptional range of research expertise, which is an ideal basis for the training and education of highly talented young investigators. “The GSN is the glue that holds this network together,” says Benedikt Grothe, neurobiology professor and designated speaker for the Graduate School. For the doctoral students who are members of the GSN work in the various affiliated institutions, and as good communicators, they serve to bind the network together, he adds. And that will not change in the coming years, he says, as the School’s future is assured beyond the end of the Excellence Initiative in 2017. At all events, over the past decade the School has built up an enviable international reputation: Applications from highly qualified candidates from around the world testify to the level of interest in postgraduate studies at the GSN, and the proportion of doctoral students from English-speaking countries has grown significantly. In addition, the numbers of proposals for collaborative ventures received has progressively increased. “We now have to decline most of these requests,” Grothe says. He focuses in this regard on carefully selected partnerships – with Harvard University, for instance, or the University of Queensland in Brisbane. “We are trying to limit the number of cooperations we enter into, although we of course remain open to offers. Our postdocs can work anywhere in the world.” Dr. Kiri Couchman, now based in Paris, is one such postdoc. She recalls with affection the friendships she made during her time at the GSN, which have persisted since she left Munich. “We all got on very well together – both in our own labs and at the weekly meetings with all the other graduate students. – And these contacts are still very much alive.” One other feature which makes the School so attractive to graduate students from abroad is its structural independence. The School confers its own Ph.D. degrees, and this clearly distinguishes it from thematically related establishments elsewhere in Germany. The GSN-LMU is undoubtedly a success story, although Benedikt Grothe admits that this was not always so: “At the outset, we seriously underestimated the scale of what we were getting ourselves into.” Meanwhile, however, alterations in the management of the GSN and in the supervision of its PhD students have corrected the consequences of the initial misjudgments, he adds. Grothe believes that the School is now on an even keel, and in particular he sees it as an important means of attracting first-rate neuroscientists to the city on the Isar. In light of the healthcare challenges posed by aging populations, the need for breakthroughs in neurobiology is becoming ever more urgent.


The method of taking these pictures is a collaborative creation that involved Kansas State University researchers Artem Rudenko and Daniel Rolles, both assistant professors of physics. The movies help scientists understand interactions of intense laser light with matter. But even more importantly, these experiments lead the way to filming various processes that involve ultrafast dynamics of microscopic samples, such as the formation of aerosols—which play a major role in climate models—or laser-driven fusion. "We can create a real movie of the microworld," Rudenko said. "The key development is that now we can take sequences of pictures on the nanoscale." Rudenko and Rolles—both affiliated with the university's James R. Macdonald Laboratory—collaborated with researchers at SLAC National Accelerator Laboratory at Stanford University, Argonne National Laboratory and the Max Planck Institutes in Germany. Their publication, "Femtosecond and nanometre visualization of structural dynamics in superheated nanoparticles," appears in Nature Photonics. In this work, the collaboration used intense lasers to heat xenon nanoscale clusters and then took a series of X-ray pictures to show what happened to the particles. The picture series became a movie of how these objects move at the level of femtoseconds, which are one-millionth of a billionth of a second. "What makes nano so interesting is that the behavior for many things changes when you get to the nanoscale," Rolles said. "Nano-objects bridge the gap between bulk matter and individual atoms or molecules. This research helps us as we try to understand the behavior of nano-objects and how they change shape and properties within extremely short times." The pictures of the nanoparticles cannot be taken with normal optical light, but must be taken with X-rays because X-ray light has nanometer wavelengths that enable researchers to view nanoscale objects, Rolles said. The light wavelength must match the size of the object. To take the pictures, the researchers needed two ingredients: very short X-ray pulses and very powerful X-ray pulses. The Linac Coherent Light Source at SLAC provided those two ingredients, and Rudenko and Rolles traveled to California to use this machine to take the perfect pictures. The photo-taking method and the pictures it produces have numerous applications in physics and chemistry, Rolles said. The method is also valuable for visualizing laser interactions with nanoparticles and for the rapidly developing field of nanoplasmonics, in which the properties of nanoparticles are manipulated with intense light fields. This may help to build next-generation electronics. "Light-driven electronics can be much faster than conventional electronics because the key processes will be driven by light, which can be extremely fast," Rudenko said. "This research has big potential for optoelectronics, but in order to improve technology, we need to know how a laser drives those nanoparticles. The movie-making technology is an important step in this direction." Rudenko and Rolles are continuing to improve the moviemaking process. In collaboration with the university's soft matter physics group, they have extended the range of samples, which can be put into the X-ray machine and now can produce movies of gold and silica nanoparticles. Explore further: Dual camera smartphones – the missing link that will bring augmented reality into the mainstream More information: Tais Gorkhover et al. Femtosecond and nanometre visualization of structural dynamics in superheated nanoparticles, Nature Photonics (2016). DOI: 10.1038/nphoton.2015.264


News Article | April 6, 2016
Site: www.nanotech-now.com

Abstract: Think of it as a microscopic movie: A sequence of X-ray images shows the explosion of superheated nanoparticles. The picture series reveals how the atoms in these particles move, how they form plasma and how the particles change shape. The method of taking these pictures is a collaborative creation that involved Kansas State University researchers Artem Rudenko and Daniel Rolles, both assistant professors of physics. The movies help scientists understand interactions of intense laser light with matter. But even more importantly, these experiments lead the way to filming various processes that involve ultrafast dynamics of microscopic samples, such as the formation of aerosols -- which play a major role in climate models -- or laser-driven fusion. "We can create a real movie of the microworld," Rudenko said. "The key development is that now we can take sequences of pictures on the nanoscale." Rudenko and Rolles -- both affiliated with the university's James R. Macdonald Laboratory -- collaborated with researchers at SLAC National Accelerator Laboratory at Stanford University, Argonne National Laboratory and the Max Planck Institutes in Germany. Their publication, "Femtosecond and nanometre visualization of structural dynamics in superheated nanoparticles," appears in Nature Photonics. In this work, the collaboration used intense lasers to heat xenon nanoscale clusters and then took a series of X-ray pictures to show what happened to the particles. The picture series became a movie of how these objects move at the level of femtoseconds, which are one-millionth of a billionth of a second. "What makes nano so interesting is that the behavior for many things changes when you get to the nanoscale," Rolles said. "Nano-objects bridge the gap between bulk matter and individual atoms or molecules. This research helps us as we try to understand the behavior of nano-objects and how they change shape and properties within extremely short times." The pictures of the nanoparticles cannot be taken with normal optical light, but must be taken with X-rays because X-ray light has nanometer wavelengths that enable researchers to view nanoscale objects, Rolles said. The light wavelength must match the size of the object. To take the pictures, the researchers needed two ingredients: very short X-ray pulses and very powerful X-ray pulses. The Linac Coherent Light Source at SLAC provided those two ingredients, and Rudenko and Rolles traveled to California to use this machine to take the perfect pictures. The photo-taking method and the pictures it produces have numerous applications in physics and chemistry, Rolles said. The method is also valuable for visualizing laser interactions with nanoparticles and for the rapidly developing field of nanoplasmonics, in which the properties of nanoparticles are manipulated with intense light fields. This may help to build next-generation electronics. "Light-driven electronics can be much faster than conventional electronics because the key processes will be driven by light, which can be extremely fast," Rudenko said. "This research has big potential for optoelectronics, but in order to improve technology, we need to know how a laser drives those nanoparticles. The movie-making technology is an important step in this direction." Rudenko and Rolles are continuing to improve the moviemaking process. In collaboration with the university's soft matter physics group, they have extended the range of samples, which can be put into the X-ray machine and now can produce movies of gold and silica nanoparticles. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

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