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  • richardmitnick 4:39 pm on July 13, 2017 Permalink | Reply
    Tags: , ETH Zurich, , Testing a soft artificial heart   

    From ETH Zürich: “Testing a soft artificial heart” 

    ETH Zurich bloc

    ETH Zürich

    13.07.2017
    Franziska Schmid

    ETH researchers from the Functional Materials Laboratory have developed a silicone heart that beats almost like a human heart. In collaboration with colleagues from the Product Development Group Zürich, they have tested how well it works.

    1
    The artificial heart imitates a human heart as closely as possible. (Photo: Zürich Heart)

    It looks like a real heart. And this is the goal of the first entirely soft artificial heart: to mimic its natural model as closely as possible. The silicone heart has been developed by Nicholas Cohrs, a doctoral student in the group led by Wendelin Stark, Professor of Functional Materials Engineering at ETH Zürich. The reasoning why nature should be used as a model is clear. Currently used blood pumps have many disadvantages: their mechanical parts are susceptible to complications while the patient lacks a physiological pulse, which is assumed to have some consequences for the patient.

    “Therefore, our goal is to develop an artificial heart that is roughly the same size as the patient’s own one and which imitates the human heart as closely as possible in form and function,” says Cohrs. A well-functioning artificial heart is a real necessity: about 26 million people worldwide suffer from heart failure while there is a shortage of donor hearts. Artificial blood pumps help to bridge the waiting time until a patient receives a donor heart or their own heart recovers.

    The soft artificial heart was created from silicone using a 3D-printing, lost-wax casting technique; it weighs 390 grams and has a volume of 679 cm3. “It is a silicone monoblock with complex inner structure,” explains Cohrs. This artificial heart has a right and a left ventricle, just like a real human heart, though they are not separated by a septum but by an additional chamber. This chamber is in- and deflated by pressurized air and is required to pump fluid from the blood chambers, thus replacing the muscle contraction of the human heart.


    The artificial heart at work (Video: ETH Zürich)

    Thinking in a new direction

    Anastasios Petrou, a doctoral student of the Product Development Group Zürich, led by Professor Mirko Meboldt evaluated the performance of this soft artificial heart. The young researchers have just published the results of the experiments in the scientific journal Artificial Organs.

    They proved that the soft artificial heart fundamentally works and moves in a similar way to a human heart. However, it still has one problem: it currently lasts for about only 3,000 beats, which corresponds to a lifetime of half to three quarters of an hour. After that, the material can no longer withstand the strain. Cohrs explains: “This was simply a feasibility test. Our goal was not to present a heart ready for implantation, but to think about a new direction for the development of artificial hearts.” Of course, the tensile strength of the material and the performance would have to be enhanced significantly.

    Zürich Heart brings researchers together

    Cohrs and Petrou met in the Zürich Heart Project, a flagship project of University Medicine Zurich that brings together 20 research groups from various disciplines and institutions in Zürich and Berlin. Part of the research focuses on improvements on existing blood pumps, such as how to reduce blood damage induced from the mechanical parts of the pump, while others explore extremely elastic membranes or more biocompatible surfaces. This is done in close collaboration with the clinicians in Zurich and Berlin.

    The lively exchanges among the researchers also helped this Zürich Heart sub-project. Doctoral students of Product Development Group Zürich, who are working on new technologies for blood pumps, have developed a testing environment with which they can simulate the human cardiovascular system. The researchers of the silicone heart made use of this testing environment for their development process which also included the use of a fluid with comparable viscosity as human blood. “Currently, our system is probably one of the best in the world,” says Petrou proudly.

    Researching the heart is an appealing task, and Cohrs and Petrou would both like to remain in this research field. “As a mechanical engineer, I would never have thought that I would ever hold a soft heart in my hands. I’m now so fascinated by this research that I would very much like to continue working on the development of artificial hearts,” says Petrou.

    See the full article here .

    Please help promote STEM in your local schools.

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    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 2:06 pm on June 19, 2017 Permalink | Reply
    Tags: , , ETH Zurich, Piz Daint, PRACE - Partnership for Advanced Computing in Europe,   

    From ETH: “Piz Daint is a world leader” 

    ETH Zurich bloc

    ETH Zürich

    19.06.2017
    Anna Maltsev
    Felix Würsten

    Cray Piz Daint supercomputer of the Swiss National Supercomputing Center (CSCS)

    After an extensive hardware upgrade at the end of last year, the CSCS supercomputer Piz Daint is now the most powerful mainframe computer outside Asia. With a peak performance in excess of 20 petaflops, it will enable pioneering research in Switzerland and Europe.

    The Piz Daint supercomputer at the Swiss National Supercomputing Centre (CSCS) has been the most powerful supercomputer in Europe since November 2013. An extensive hardware upgrade at the end of 2016 has now more than tripled its performance. Piz Daint is now the fastest computer outside Asia, with a theoretical peak performance of 25.3 petaflops, as confirmed today at the international ISC High Performance event in Frankfurt. Thanks to its innovative architecture, Piz Daint is also one of the most energy-efficient mainframe computer in the world.

    Strategic approach

    The upgraded supercomputer is an energy-efficient hybrid system consisting of conventional processors (CPUs) and graphics processors (GPUs). The sophisticated system, based on a Cray XC40/XC50, is the result of a long-standing collaboration between CSCS, various hardware manufacturers, computer scientists, mathematicians and other researchers from different disciplines. This successful collaboration was initiated by the national Strategic Plan for High Performance Computing and Networking (HPCN Strategy) that was launched by the ETH Board on behalf of the federal government in 2009.

    Support for research

    Supercomputers are now an integral part of research: in addition to theory and experiments, simulations, data analyses and visualisations now also make key contributions to most research areas. Powerful systems such as Piz Daint are crucial for high-resolution computer-intensive simulations, such as those used in climate or material research, or in the life sciences.

    In data science, which has an increasingly important role and is one of ETH Zürich’s main focus areas, supercomputers enable the analysis of enormous amounts of data. This is an area in which Piz Daint is particularly strong: it is able to analyse the resulting data while the calculations are still ongoing.

    Important for international cooperation

    Piz Daint is also an important element in international research collaborations: as of this spring, CSCS with Piz Daint is one of the main providers of computing power in the Partnership for Advanced Computing in Europe (PRACE). This commitment then benefits Swiss researchers in turn, as CSCS’s participation in PRACE gives them access to various other European supercomputers.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 3:30 pm on December 9, 2016 Permalink | Reply
    Tags: , ETH Zurich, , New weapon against Diabetes   

    From ETH Zürich: “New weapon against Diabetes” 

    ETH Zurich bloc

    ETH Zürich

    08.12.2016
    Peter Rüegg

    Researchers have used the simplest approach yet to produce artificial beta cells from human kidney cells. Like their natural model, the artificial cells act as both sugar sensors and insulin producers.

    1
    Repeated measurement of the blood glucose level and injection of insulin make the everyday life of diabetics complicated. The newly created beta cells of the ETH researchers could make life easier again. (Picture: Dolgachov / iStock)

    Researchers led by ETH Professor Martin Fussenegger at the Department of Biosystems Science and Engineering (D-BSSE) in Basel have produced artificial beta cells using a straightforward engineering approach. These pancreatic cells can do everything that natural ones do: they measure the glucose concentration in the blood and produce enough insulin to effectively lower the blood sugar level. The ETH researchers presented their development in the latest edition of the journal Science.

    Previous approaches were based on stem cells, which the scientists allowed to mature into beta cells either by adding growth factors or by incorporating complex genetic networks.

    For their new approach, the ETH researchers used a cell line based on human kidney cells, HEK cells. The researchers used the natural glucose transport proteins and potassium channels in the membrane of the HEK cells. They enhanced these with a voltage-dependent calcium channel and a gene for the production of insulin and GLP-1, a hormone involved in the regulation of the blood sugar level.

    Voltage switch causes insulin production

    In the artificial beta cells, the HEK cells’ natural glucose transport protein carries glucose from the bloodstream into the cell’s interior. When the blood sugar level exceeds a certain threshold, the potassium channels close. This flips the voltage distribution at the membrane, causing the calcium channels to open. As calcium flows in, it triggers the HEK cells’ built-in signalling cascade, leading to the production and secretion of insulin or GLP-1.

    2
    Diagram of a HEK-beta cell: Extracellular glucose triggers glycolysis-dependent membrane depolarization, which activates the voltage-gated calcium channel, resulting in an influx of Calcium ions, induction of the calmodulincalcineurin signaling cascade, and PNFAT-mediated induction of insulin secretion. (Graphics: ETH Zürich)

    The initial tests of the artificial beta cells in diabetic mice revealed the cells to be extremely effective: “They worked better and for longer than any solution achieved anywhere in the world so far,” says Fussenegger. When implanted into diabetic mice, the modified HEK cells worked reliably for three weeks, producing sufficient quantities of the messengers that regulate blood sugar level.

    Helpful modelling

    In developing the artificial cells, the researchers had the help of a computer model created by researchers working under Jörg Stelling, another professor in ETH Zürich’s Department of Biosystems Science and Engineering (D-BSSE). The model allows predictions to be made of cell behaviour, which can be verified experimentally. “The data from the experiments and the values calculated using the models were almost identical,” says Fussenegger.

    He and his group have been working on biotechnology-based solutions for diabetes therapy for a long time. Several months ago, they unveiled beta cells that had been grown from stem cells from a person’s fatty tissue. This technique is expensive, however, since the beta cells have to be produced individually for each patient. The new solution would be cheaper, as the system is suitable for all diabetics.

    Market-readiness is a long way off

    It remains uncertain, though, when these artificial beta cells will reach the market. They first have to undergo various clinical trials before they can be used in humans. Trials of this kind are expensive and often last several years. “If our cells clear all the hurdles, they could reach the market in 10 years,” the ETH professor estimates.

    Diabetes is becoming the modern-day scourge of humanity. The International Diabetes Federation estimates that more than 640 million people worldwide will suffer from diabetes by 2040. Half a million people are affected in Switzerland today, with 40,000 of them suffering from type 1 diabetes, the form in which the body’s immune system completely destroys the insulin-producing beta cells.

    Reference

    Xie M et al. Beta-cell-mimetic designer cells provide closed-loop glycemic control. Science, Advanced Online Publication, 8 November 2016, DOI: 10.1126/science.aaf4006

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 2:48 pm on October 27, 2016 Permalink | Reply
    Tags: , , ETH Zurich, How planets like Jupiter form   

    From ETH Zürich 

    ETH Zurich bloc

    ETH Zürich

    10.27.16
    Barbara Vonarburg

    Young giant planets are born from gas and dust. Researchers of ETH Zürich and the Universities of Zürich and Bern simulated different scenarios relying on the computing power of the Swiss National Supercomputing Centre (CSCS) to find out how they exactly form and evolve. They compared their results with observations and were able to show amongst others a big difference between the postulated formation mechanisms.

    1
    Core accretion: A 10 Jupiter-mass planet is formed and is placed at 50 AU from the star. The planet has opened a gap in the circumstellar disk. (Image: J. Szulagyi, JUPITER code)

    Astronomers set up two theories explaining how gaseous giant planets like Jupiter or Saturn could be born. A bottom-up formation mechanism states that first, a solid core is aggregated of roughly ten times the size of the Earth. «Then, this core is massive enough to attract a significant amount of gas and keep it,» explains Judit Szulágyi, post-doctoral fellow at the ETH Zürich and member of the Swiss NCCR PlanetS. The second theory is a top-down formation scenario: Here the gaseous disk around the young star is so massive, that due to self-gravity of the gas-dust, spiral arms are forming with clumps inside. Then, these clumps collapse via their own gravity directly into a gaseous planet, similar to how stars form. The first mechanism is called «core-accretion», the second one «disk instability». In both cases, a disk forms around the gas-giants, called the circumplanetary disk, which will serve as a birth-nest for satellites to form.

    To find out which mechanism actually takes place in the Universe, Judit Szulágyi and Lucio Mayer, Professor at the University of Zürich, simulated the scenarios on Piz Daint supercomputer at the Swiss National Supercomputing Centre (CSCS) in Lugano. «We pushed our simulations to the limits in terms of the complexity of the physics added to the models,» explains Judit Szulágyi: «And we achieved higher resolution than anybody before.» In their studies published in the «Monthly Notices of the Royal Astronomical Society» the researchers found a big difference between the two formation mechanisms: In the disk instability scenario the gas in the planet’s vicinity remained very cold, around 50 Kelvins, whereas in the core accretion case the circumplanetary disk was heated to several hundreds of Kelvins. «The disk instability simulations are the first that can resolve the circumplanetary disk around multiple protoplanets, using tens of millions of resolution elements in the computational domain. We exploited Piz Daint to accelerate the calculations using Graphics Processing Units (GPUs)” adds Mayer.

    This huge temperature difference is easily observable. «When astronomers look into new forming planetary systems, just measuring the temperatures in the planet’s vicinity will be enough to tell which formation mechanism built the given planet,» explains Judit Szulágyi. A first comparison of the calculated and observed data seems to favour the core accretion theory. Another difference that was expected didn’t show up in the computer simulation. Before, astrophysics thought that the circumplanetary disk significantly differs in mass in the two formation scenarios. «We showed that this is not true,» says the PlanetS member.

    2
    Gravitational instability simulation: Two snapshots in the early and late stage of the simulation at 780 years and 1942 years. The second snapshot shows only 4 clumps remaining among those initially formed. (Image: Lucio Mayer & T. Quinn, ChaNGa code)

    Luminous shock front detected

    Regarding the size of the new born planet, observations can be misleading as the astrophysicist found in a second study together with Christoph Mordasini, Professor at the University of Bern. In the core accretion model the researchers had a closer look at the disk around planets with masses three to ten times bigger than Jupiter’s. The computer simulations showed that gas falling on the disk from the outside heats up and creates a very luminous shock front on the disk’s upper layer. This significantly alters the observational appearance of young, forming planets.

    «When we see a luminous spot inside a circumplanetary disk, we cannot be sure whether we see the planet luminosity, or also the surrounding disk luminosity,» says Judit Szulágyi. This may lead to an overestimation of the planet’s mass of up to four times. «So maybe an observed planet has only the same mass as Saturn instead of some Jupiter masses,» concludes the scientist.

    In their simulations the astrophysicists mimicked the formation processes by using the basic physical laws such as gravity or the hydrodynamical equations of the gas. Because of the complexity of the physical models the simulations were very time consuming, even on Europe’s fastest supercomputer at CSCS: «On the order of nine months running time on hundreds to several thousands of computing cores» estimates Judit Szulágyi: «This means that on one computing core it would have taken longer than my entire lifetime.»

    Yet there are still challenges ahead. Simulations of disk instability still do not cover a long timescale. It is possible that after the protoplanet has collapsed to the density of Jupiter its disk will heat up more like in core-accretion. Likewise, the hotter gas found in the core-accretion case would be partially ionized, a favourable environment for effects of magnetic fields, completely neglected so far. Running even more expensive simulations with a richer description of the physics will be the next step. (bva)

    Publications:
    Szulagyi; L. Mayer; T. Quinn: Circumplanetary disks around young giant planets: a comparison between core-accretion and disk instability, Monthly Notices of the Royal Astronomical Society 2016;
    doi: 10.1093/mnras/stw2617

    Szulagyi; C. Mordasini: Thermodynamics of Giant Planet Formation: Shocking Hot Surfaces on Circumplanetary Disks, Monthly Notices of the Royal Astronomical Society: Letters 2016;
    doi: 10.1093/mnrasl/slw212

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 11:43 am on September 27, 2016 Permalink | Reply
    Tags: Book Anna Garry Thomas Feurer A Journey into Time in Powers of Ten, ETH Zurich, Expanding the horizons of experience, NCCR MUST, , Ultrafast processes, Ultrashort research   

    From ETH Zürich: “Ultrafast processes in the blink of an eye” 

    ETH Zurich bloc

    ETH Zürich

    26.09.2016
    Florian Meyer

    Ultrafast processes beyond the human imagination occur in nature, but basic research has been able to measure and explore them only since the turn of the millennium. A book and an exhibition by the National Centre of Competence in Research Molecular Ultrafast Science and Technology (NCCR MUST) now connect this to everyday life by inviting you on a journey into time.

    1
    In recent years, ultrafast laser physics – such as Ursula Keller’s Attoline laboratory – has ventured into increasingly smaller units of time: today, measurements are possible in the attosecond or trillionth of a second range. (Photo: ETH Zurich/H. Hostettler)

    The exhibition, which is located in the entrance of Campus Info at ETH Hönggerberg until mid-December, can be enjoyed in no time at all. The name says it all – “Fast”. Several posters present image sequences with processes that take place very quickly – or slowly – and at the same time provide an insight into “ultrafast research”.

    Some processes occur so quickly in nature that the blink of an eye is by comparison very slow. A light wave, for example, is ultrafast, rising and falling again in a mere two quadrillionths of a second. In scientific terms, this is two femtoseconds or, when written as the power of ten, 2·10−15 seconds.

    Even faster are elementary particles such as electrons or photons: when they move in molecules, it takes an ultrafast 100 trillionths of a second, which is 100 attoseconds or 10−16 s. No one is able to see such ultrafast processes with the naked eye, and even for basic research it is comparatively uncharted territory.

    Expanding the horizons of experience

    Basic and essential physical, chemical and biological reactions take place in the ultrafast time scale between nanoseconds (10−9 s) and attoseconds (10−18 s). Understanding them can help in the development of alternative sources of energy, new data storage and medical applications, such as artificial blood.

    “The human senses perceive light and speed in only a very limited manner,” says Ursula Keller. “This is why we are attempting to expand the horizons of experience through research.” Throughout her career, the ETH Professor of Experimental Physics has contributed to the research to venture into increasingly smaller units of time.

    Only since the turn of the millennium has basic research been able to measure and investigate processes in the attosecond range. The breakthrough came thanks to the development of new light sources, such as the new X-ray radar SwissFEL at the Paul Scherrer Institute, based on ultrashort light and laser pulses.

    Today, “ultrafast research” comprises subjects such as physics, chemistry, biology and materials science, which are linked together at NCCR MUST. Keller is the co-director of MUST and her Ultrafast Laser Physics group has contributed to the rapid development.

    Linking ultrashort research and everyday life

    Uncharted territory for research poses a challenge for public communication and the dissemination of knowledge to schools, as neither ultrafast processes nor the research technologies and mathematical notations and models used to explore them are really tangible to lay people.

    To establish a link between “ultrashort research” and everyday life, Thomas Feurer, co-director of NCCR MUST and a physics professor at the University of Bern, and Anna Garry, responsible for public communication at NCCR MUST, pursued an idea that had come to Jürg Osterwalder, Professor of Surface Physics at the University of Zurich, while he was on the train.

    The idea was to invite non-specialists on a journey into ultrafast processes. The result was the book A Journey into Time in Powers of Ten, as well as exhibitions at Scientifica 2015, the Festival de Science 2016 in Neuchâtel and now at Hönggerberg. The material is also being used in exchanges with schools.

    “We would like to make schools and the public excited about our research, inspire them to think about time and the duration of essential processes, and show them how these processes can be expressed numerically,” says Garry, relating how her six-year-old nephew was fascinated by the series of images and immediately asked questions.

    The starting point of the journey into time – in both the book and the exhibition – is the blink of an eye: this takes one second or 100 s. In everyday life, blinking is the smallest felt unit in which a human perceives events in their environment. Proceeding from this, the journey travels ten steps from blinking to the attosecond.

    Each step corresponds to a power of ten and is connected to one aspect of ultrafast research by a short story. In addition to scientific facts, excerpts from the daily lives of the researchers also appear, rendering numerical reflections about essential processes clear and comprehensible.

    Insight into fast and slow processes

    A person has a thought in a tenth of a second or 10-1 s. Walking 100 metres takes about ten seconds or 101 s. Someone travelling by train from Zurich to Geneva requires 2¾ hours or 104 s. Conversely, lightning takes only 10-4 s.

    A doctoral student in their fourth year has put in about 108 s towards their education, whereas a jellyfish in the sea needs only 10-8 s to glow green. “We can easily imagine the step from blinking to sprinting. So when we take these ten steps ten times, we arrive at our research in a way that can be understood,” says Feurer.

    “As many people find it much more difficult to imagine powers of ten in the minus range than in the plus range, we have juxtaposed the slow processes with the fast.” The slowest process presented in the book and exhibition is the formation of the Milky Way, which has been dragging on for more than 30 billion years or 10^18 s.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 6:27 am on July 23, 2016 Permalink | Reply
    Tags: A high-speed motor for satellites, , ETH Zurich   

    From ETH Zürich: “A high-speed motor for satellites” 

    ETH Zurich bloc

    ETH Zürich

    22.07.2016
    Peter Rüegg

    1
    rda Tüysüz (ETH/PES; sitting in front) and an employee of Celeroton work on the new ultra-fast motor in their laboratory. (Photograph: PES/Celeroton)

    A dizzying 150,000 revolutions per minute: researchers from ETH Zürich (Department of Information Technology and Electrical Engineering) and the ETH spin-off Celeroton have developed an ultra-fast magnetically levitated electric motor for reaction wheels. The high speed of rotation allows intensive miniaturisation of the drive system, making it attractive for use in small satellites.

    “Actually, there is nothing particularly new about it,” is the modest line taken by Arda Tüysüz, a postdoc at ETH Zürich’s Power Electronic Systems Laboratory (PES). “The electronics, the magnetic bearings, understanding of the basic physical principle – it was all there already.” However, the engineering skill of the PES researchers is evident in their ability to combine these fundamentals into high-speed motor, which can run 20 times faster than the state of the art, and which is vastly smaller and more energy-efficient. In collaboration with the ETH spin-off Celeroton, Tüysüz and colleagues have developed a new kind of magnetically levitated reaction wheel motor that reaches speeds of more than 150,000 revolutions per minute.

    Electrically driven reaction wheels of this kind are used within satellites to change the satellite’s attitude. Here, the reaction wheel is connected to an electric motor via a shaft (rotor). As soon as the flywheel driven by this motor rotates in one direction about its own axis, a torque is transmitted to the satellite, which then rotates in the opposite direction and thus a new orientation.

    Existing systems have numerous disadvantages

    In existing systems, the rotors and reaction wheels are typically mounted on ball bearings that wear down relatively quickly. In order to minimise mechanical wear, motors of this kind are usually operated slower than 6,000 revolutions per minute. They also have to be stored in a hermetically sealed housing in a low-pressure nitrogen atmosphere, in order to avoid oxidisation of the materials and evaporation of the lubricant.

    Furthermore, the balls in a ball bearing are not exactly identical, giving rise to forces that together with the imbalance of the rotor transfer microvibrations to the satellite’s housing. This reduces the positioning accuracy, which satellites must exhibit in order to allow, for example, laser measurement or inter-satellite communication. In other words, enough reasons for ETH Zürich and Celeroton to design a new, magnetically levitated electric drive system.

    2
    Components of the reaction wheel motor and their assemblage. (Photo: from Zwyssig et al., 2014)

    A floating motor does not wear out

    The development work began a few years ago with a doctoral thesis at PES. An initial demonstration unit was presented by the researchers two years ago at a specialist conference in Japan. More recently, at an international symposium in June this year, they presented an initial prototype of a new kind of motor for small satellites.

    This prototype can be operated at up to 150,000 rpm – faster than comparable models in the past, as the rotor floats in a magnetic field. The high rotational speed has allowed the researchers to achieve a marked reduction in the size of the drive system, since it delivers the same angular momentum as a large motor despite its smaller dimensions. This makes it attractive for use in small satellites with sizes on the scale of a shoebox.

    “Magnetic support also allows us to avoid the vibrations,” says Tüysüz. As the system does not require lubrication, it can be operated in a vacuum, which makes it perfect for use in space. In addition, magnetic support also enables the reaction wheel to rotate softly and smoothly, as there is no frictional resistance when the system starts to move.

    European Space Agency interested in the system

    “Viewed as a whole, the new system we have developed is complex,” says Tüysüz. Sophisticated power electronics are needed to steer and control it. “This ties in perfectly with another core area of the Power Electronic Systems Laboratory’s expertise,” says the electrical engineer. Tüysüz is currently working on how to further develop and improve the system’s control electronics.

    The system developed by the ETH researchers and their colleagues at Celerotron is only a prototype that was used to demonstrate the operating principle. The results have been presented on conferences, but the system is not yet commercially available. Nevertheless, initial interest has already been expressed by various parties, chiefly the European Space Agency (ESA).

    This project was supported financially by the State Secretariat for Education, Research and Innovation (SERI).

    References

    Kaufmann M, Tüysüz A, Kolar JW, Zwyssig C: High-Speed Magnetically Levitated Reaction Wheels for Small Satellites, Proceedings of the 23rd International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM 2016), Anacapri, Capri, Italy, June 22-24, 2016.

    Zwyssig C, Baumgartner T, Kolar JW: High-Speed Magnetically Levitated Reaction Wheel Demonstrator. Proceedings of the International Power Electronics Conference – ECCE Asia (IPEC 2014), Hiroshima, Japan, May 18-21, 2014.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 8:21 am on July 15, 2016 Permalink | Reply
    Tags: , ETH Zurich, Extracting the content of single living cells   

    From ETH Zürich: “Extracting the content of single living cells” 

    ETH Zurich bloc

    ETH Zürich

    14.07.2016
    Fabio Bergamin

    Biologists are increasingly interested in the behaviour of individual cells, rather than the one of an entire cell population. A new method developed at ETH could revolutionise single cell analysis. The technology uses the world’s smallest syringe to sample the content of individual cells for molecular analyses.

    1
    FluidFM, a technology developed at ETH Zurich, allows researchers to extract the content of single living cells for molecular analyses. (Visualisations: ETH Zürich)

    ETH researchers have developed a method using a nanosyringe whose tiny needle is able to penetrate single living cells and extract their content. The technology can be used for cell cultures, for example, in order to investigate the interior of the cells. This allows scientists to identify the differences between individual cells at the molecular level, as well as to identify and analyse rare cell types. “Our method opens up new frontiers in biological research. It is the start of a whole new chapter, so to speak”, says Professor Julia Vorholt from the Department of Biology.

    The new method has numerous advantages: researchers can sample individual cells of a tissue culture directly in the petri dish. “This means we can study how a cell affects its neighbouring cells”, says Orane Guillaume-Gentil, a postdoc in Professor Vorholt’s research group. This type of investigation is not possible using conventional methods, as molecular analyses generally require the cells to first be physically separated and then destroyed.

    2
    Green colored cytosol is withdrawn from a cell (microscopic view from above). Black is the FluidFM cantilever; the needle is located in the center of the image. (Micrograph: ETH Zurich / Orane Guillaume-Gentil)

    Cells remain alive

    On top of that, the microscopic needle can be controlled so precisely that scientists are able either to harvest the content of the nucleus or collect the intracellular fluid surrounding the nucleus, the cytosol. Last but not least, the researchers can determine the amount of intracellular material they extract with incredible accuracy, down to one tenth of a pictolitre (one trillionth of a litre). By way of comparison: the volume of a cell is 10 to 100 times bigger.

    3
    Principle of the single cell analyses using FluidFM. (Visualisations: Guillaume-Gentil O et al. Cell 2016)

    The cells from which molecules were extracted remain alive, so researchers are free to sample the same live cell several times in order to analyse its RNA and proteins – and possibly even metabolites in the future. “We were surprised to find that the cells we examined survived even after we had extracted most of their cytosol”, says ETH professor Vorholt. This underscores the amazing plasticity of biological cells.

    Applications expanded

    The new cell extraction method is based on a microinjection system developed at ETH over the past years, the FluidFM, which is the “world’s smallest automated syringe”. This already gave biologists a way to inject substances into individual cells. FluidFM and its nanosyringe were also ideal for gently sucking up cells through underpressure and relocating them elsewhere.

    Professor Vorholt and her research group took the system a stage further, allowing material to be extracted from the cell compartment as well. “One particularly important aspect was to find a suitable coating for the needle, to prevent fouling by cell material”, comments Guillaume-Gentil. Another challenge was to adapt the analysis techniques used for the cell molecules – for measuring enzyme activity, for example – to the minute measurement volumes. The latest development of the system was carried out in close collaboration with researchers working under Tomaso Zambelli, Privatdozent at ETH Zurich’s Department of Information Technology and Electrical Engineering, Martin Pilhofer, Professor at the Institute of Molecular Biology and Biophysics, and the ETH spin-off Cytosurge, which markets the FluidFM technology.

    Reference

    Guillaume-Gentil O, Grindberg RV, Kooger R, Dorwling-Cater L, Martinez V, Ossola D, Pilhofer M, Zambelli T, Vorholt JA: Tunable single-cell extraction for molecular analysis. Cell 2016, 166: 506-516, doi: 10.1016/j.cell.2016.06.025

    See the full article here .

    Please help promote STEM in your local schools.

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    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 10:24 am on April 14, 2016 Permalink | Reply
    Tags: , ETH Zurich,   

    From ETH Zürich: “Bubbles lead to disaster” 

    ETH Zurich bloc

    ETH Zürich

    13.04.2016
    Peter Rüegg

    Why are volcanologists interested in vapour bubbles? Because they can accumulate in a magma reservoir underneath a volcano, priming it to explode. Researchers at ETH Zürich and Georgia Institute of Technology have now discovered how bubbles are able to accumulate in the magma.

    1
    Tambora on the Indonesian island of Sumbawa: The explosive eruption of this volcano 200 years ago cooled the climate and lead to a year without a summer. (Photo: Jialiang Gao / Wikimedia Commons CC BY-SA 3.0)

    In 1816, summer failed to make an appearance in central Europe and people were starving. Just a year earlier, the Tambora volcano had erupted in Indonesia, spewing huge amounts of ash and sulphur into the atmosphere. As these particles partly blocked sunlight, cooling the climate, it had a serious impact on the land and the people, even in Switzerland.

    Since then, volcanologists have developed more precise ideas of why super-volcanoes such as Tambora are not only highly explosive but also why they release so much sulphur into the atmosphere. Gas bubbles tend to accumulate in the upper layers of magma reservoirs, which are only a few kilometres beneath the earth’s surface, building up pressure that can then be abruptly liberated by eruption. These bubbles mainly contain water vapour but also sulphur.

    Sulphur-rich eruptions

    2
    The zonation of a magma reservoir is strongly influencing the rise and accumulation of bubbles containing water vapour and other volatile elements such as sulphur. (Scheme: from Parmigiani et al., Nature 2016)

    “Such volcanic eruptions can be extremely powerful and spew an enormous amount of ash and sulphur to the surface,” says Andrea Parmigiani, a post-doc in the Institute of Geochemistry and Petrology at ETH Zürich. “We’ve known for some time that gas bubbles play a major role in such events, but we had only been able to speculate on how they accumulate in magma reservoirs.”

    Together with other scientists from ETH Zürich and Georgia Institute of Technology (Georgia Tech), the researchers studied the behaviour of bubbles with a computer model. The scientists used theoretical calculations and laboratory experiments to examine in particular how bubbles in crystal-rich and crystal-poor layers of magma reservoirs move buoyantly upward. In many volcanic systems, the magma reservoir consists mainly of two zones: an upper layer consisting of viscous melt with almost no crystals, and a lower layer rich in crystals, but still containing pore space.

    Super bubbles meander through a maze

    When Andrea Parmigiani, Christian Huber and Olivier Bachmann started this project, they thought that the bubbles, as they moved upwards through crystal-rich areas of the magma reservoirs, would dramatically slow down, while they would go faster in the crystal-poor zones. “Instead, we found that, under volatile-rich conditions, they would ascend much faster in the crystal-rich zones, and accumulate in the melt-rich portions above” says Parmigiani.

    Parmigiani explains this as follows: when the proportion of bubbles in the pore space of the crystal-rich layers increases, small individual bubbles coalesce into finger-like channels, displacing the existing highly viscous melt. These finger-like channels allow for a higher vertical gas velocity. The bubbles, however, have to fill at least 10 to 15 % of the pore space. “If the vapour phase cannot form these channels, individual bubbles are mechanically trapped,” says the earth scientist.

    3
    Simulation of buoyant bubbles in crystal-rich magma (blue layer) and in an crystal-poor melt (top layer). (Visualizations: ETH Zürich / Andrea Parmigiani)

    As these finger-like channels reach the boundary of the crystal-poor melt, individual, more spherical bubbles detach, and continue their ascent towards the surface. However, the more bubble, the more reduce their migration velocity is. This is because each bubble creates a return flow of viscous melt around it. When an adjacent bubble feels this return flow, it is slowed down. This process was demonstrated in a laboratory experiment conducted by Parmigiani’s colleagues Salah Faroughi and Christian Huber at Georgia Tech, using water bubbles in a viscous silicone solution.

    “Through this mechanism, a large number of gas bubbles can accumulate in the crystal-poor melt under the roof of the magma reservoir. This eventually leads to overpressurization of the reservoir,” says lead author Parmigiani. And because the bubbles also contain sulphur, this also accumulates, explaining why such a volcano might emit more sulphur than expected based on its composition.

    What this means for the explosivity of a given volcano is still unclear. “This study focuses primarily on understanding the basic principles of gas flow in magma reservoirs; a direct application to prediction of volcanic behaviour remains a question for the future,” says the researcher, adding that existing computer models do not depict the entire magma reservoir, but only a tiny part of it: roughly a square of a few cm3 with a clear boundary between the crystal-poor and crystal-rich layers.

    To calculate this small volume, Parmigiani used high-performance computers such as the Euler Cluster at ETH Zürich and a supercomputer at the Swiss National Supercomputing Centre in Lugano. For the software, the researcher had access to the open-source library Palabos, which he continues to develop in collaboration with researchers from University of Geneva. “This software is particularly suitable for this type of simulation,” says the physicist.

    Reference

    Science paper
    Parmigiani A, Faroughi S, Huber C, Bachmann O, Su Y: Bubble accumulation and its role in the evolution of magma reservoirs in the upper crust. Nature, 13 April 2016. doi: 10.1038/nature17401

    Science team:
    A. Parmigiani, S. Faroughi, C. Huber, O. Bachmann & Y. Su

    Affiliations

    Institute of Geochemistry and Petrology, ETH Zurich, Zurich 8092, Switzerland
    A. Parmigiani & O. Bachmann
    School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Georgia 30332, USA
    A. Parmigiani, S. Faroughi, C. Huber & Y. Su
    School of Civil and Environmental Engineering, Georgia Institute of Technology, Georgia 30332, USA
    S. Faroughi & C. Huber

    Contributions

    C.H., O.B. and A.P. conceived the research. C.H. and, to a lesser extent, A.P. developed the physical model. A.P. performed the numerical modelling and analysed the results. S.F. developed the laboratory experiments and theoretical model for the transport of volatiles in crystal-poor magmas. Y.S. led the discussion on excess sulfur. C.H., O.B. and A.P. all wrote the manuscript.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 10:02 am on January 19, 2016 Permalink | Reply
    Tags: , Atmospheric aerosols, , ETH Zurich   

    From ETH: “Bacchus brightens up atmospheric aerosols” 

    ETH Zurich bloc

    ETH Zürich

    19.01.2016
    Christina Schnadt

    Although Bacchus, the Roman god of wine, has lent his name to an ongoing research project on the interactions between aerosols, clouds and climate, he seems not to have clouded the scientists’ capacity for analytical thought: After two years of research, the BACCHUS project team has now issued its mid-term summary for policy makers.

    Temp 1
    Measuring the atmosphere above Cyprus using an unmanned aerial vehicle (UAV), at the international ChArMEx campaign, March 2015. (Photo: Greg Roberts / CNRS-GAME)

    Are you one of those people who associate the name Bacchus with the Roman god of wine and revelry? ETH Zürich, 19 European and one Israeli research team – a gathering of leading experts in aerosol and climate research – have given this term an entirely different meaning: our BACCHUS stands for “Impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding” [1]. It is the acronym of a four-year EU FP7 research project which began in 2013 and is coordinated by Professor Ulrike Lohmann at the Institute of Atmospheric and Climate Science at ETH (see this blog post on BACCHUS). Two years into the project, we have now published a first report for policy makers and interested non-professionals [2], which presents the main findings in a clear and concise way.
    Aerosols and clouds as uncertainty factors

    Cloud droplets and ice crystals form around an individual tiny seed – called an aerosol. These aerosols can be of natural origin, such as dust, pollen, or salt from sea spray, or they can be man-made, emitted by diesel cars or industry, for instance. As the latest Intergovernmental Panel on Climate Change (IPCC) report states [3], the interactions between aerosols and clouds are a major uncertainty in climate projections (see also Ulrike Lohmann’s Klimablog post). This uncertainty is partly due to a lack of fundamental understanding of ice-containing clouds and of the coupling between the biosphere and the atmosphere.

    BACCHUS explores these two topics in detail, addressing important questions such as: how do clouds respond to a changing climate? Does melting Arctic sea ice lead to changes in Arctic cloud formation and hence to an increased or decreased warming of the Arctic? How do plants react to changes in rising concentrations of carbon dioxide? Will they emit more biogenic aerosol particles that may change cloud properties? Will the altered clouds produce more rain, which in turn would lead to an enhanced biomass production?

    Temp 2
    Biosphere-atmosphere-climate feedback: During photosynthesis, plants emit organic gases, called biogenic volatile organic compounds (BVOCs), which form particles in the atmosphere. Some of these particles influence cloud formation. In a warmer climate, if vegetation zones do not change, emissions of BVOCs will increase, leading to climate feedback. (adopted from Fang et al., 2014, [4])

    Measuring ice-forming cloud seeds

    One of our main achievements is that we have collected and stored worldwide observational data on seeds for ice crystals, known as ice nucleating particles (INP), in the newly launched BACCHUS INP database. To complement already existing data, BACCHUS partners took part in several international measurement campaigns in 2015.

    Understanding processes in clouds

    Our scientists evaluate these data in a joint effort to better understand differences in INP and their interactions with clouds in three different key cloud regimes: tropical thunderstorm clouds in a region of high aerosol variability from wildfires and urban influence, sub-tropical shallow fair weather clouds, and Arctic summer clouds, that cause overcast and hazy conditions in a region almost entirely free of anthropogenic aerosols. For these case studies, the researchers apply process models which include the details of cloud droplet, ice crystal, rain and snow formation in an individual cloud. Due to their high spatial and temporal resolution, the models are ideal for directly comparing with the measurements conducted and compiled in BACCHUS.

    Simulating feedback processes in climate models

    In the first two years of the project we have developed improved descriptions of aerosol and cloud processes – called parameterizations – for use in global Earth System models (ESMs). ESMs enable us to simulate the interactions between the sub-systems that influence climate, i.e. the atmosphere, ocean, biosphere, land surface, and soil. We have developed parameterizations for releases of organic aerosols from the ocean to the atmosphere, as well as for emissions of aerosols from continental plants (biogenic volatile organic compounds, BVOCs). Two of the BACCHUS ESMs are now able to simulate releases of BVOCs to the atmosphere in a changing climate. This is one fundamental step towards improved climate change scenarios that will be carried out in the second half of BACCHUS.

    Where do we go from here?

    Climate change is one of the most significant challenges that humankind currently faces. For the second half of BACCHUS, we expect to further unravel the complexities of aerosol and cloud processes and hence reduce the uncertainties of future climate predictions. Our projections will contribute to international assessments such as IPCC, and thus may guide politicians and other stakeholders to develop strategies for air pollution control, mitigation and adaptation of climate change. Let’s drink to that!

    Further Information

    [1] Project BACCHUS: Impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding

    [2] Mid-term summary for policymakers: Report

    [3] IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.

    [4] Fang, K., R. Makkonen, Z. Guo, and H. Seppä, 2014: An increase in the biogenic aerosol concentration factor to the recent wetting trend in Tibetan Plateau, Nature, Sci. Reports, 5:14628, doi:10.1038/srep14628.

    See the full article here .

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    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
  • richardmitnick 5:48 pm on January 2, 2016 Permalink | Reply
    Tags: , , ETH Zurich   

    From ETH Zürich: “A multitool for cells” 

    ETH Zurich bloc

    ETH Zürich

    20.12.2015
    Peter Rüegg

    Cells have an infallible sense of smell that tells them which direction to grow in to move closer to the source of a scent. ETH researchers have now learned how this sense of smell works.

    Temp 1
    The polarity site (yellow traces) is a sensor, processor and motor all in one – a multifunctional instrument that controls cell growth and movement. (Graphics: ETH Zürich)

    A frequent problem faced by cells is that they are surrounded by a promising cloud of scent and must determine the direction of its source. Nerve cells, for example, form long extensions that are attracted to signals from other cells in order to produce the network that forms the nervous system; similarly, scavenger cells recognise the scent of harmful germs in order that they can pursue and destroy them.

    But how do cells sense these scent signals, which become weaker and weaker with increasing distance from the source? How do cells ‘read’ this weakening of the signal – technically referred to as a signal gradient – in order to steer their growth or movement towards the signal’s source? How spatial signals are sensed is a fundamental question facing biology – and until now this riddle has remained largely unsolved.

    Sensor, processor and motor all in one

    Now, a possible solution has been presented by researchers led by ETH Professor Matthias Peter of the Institute of Biochemistry. Yeast cells have a very fine, adjustable multitool that recognises chemical signals, processes them accordingly, and initiates the correct response – growth towards the source of the signal. Yeast cells are therefore able to smell the location of potential sexual partners in their surroundings, so that they can grow towards them.

    The biologists conducted their study using a combination of microscopic observations and a computer model that they developed through an interdisciplinary collaboration with researchers from the Automatic Control Lab under Heinz Koeppl (now at TU Darmstadt).

    Many proteins form multi tool

    If the cell suspects that a signal gradient is nearby, it assembles the multitool at a random position on the membrane. This tool is a large protein complex made up of more than 100 different components; the complex is so big that it can be seen through a fluorescence microscope. The researchers call this a ‘polarity site’ (PS) because polarised growth sets in at the location where it forms.

    Using fluorescence microscopy, the researchers have now observed how the PS locates a gradient’s signal source. First, the PS moves along the membrane towards the stronger signal. Once it has identified the strongest signal – i.e. the largest amount of signal substance in the gradient – it stops moving. The PS then creates a bulge in the cell at this location, which continues to grow towards the source of the signal. Naturally, the signal is produced by a sexual partner and the two cells fuse once they have found one another.

    Complex structure reduced using a model

    In order to understand the molecular mechanics of this process, the researchers referred to the computer model. “This model really helped us to reduce the complexity of the PS and the process to a few essential components,” says Björn Hegemann, lead author of a study published in the journal Development Cell. These essential components of the machinery include a receptor that picks up and forwards the signal; others include the protein Cdc42, which carries the receptor along the membrane, and the protein Cdc24, which regulates the activity of Cdc42. “You could describe the receptor as the nose, Cdc42 as the wheel of the machinery and Cdc24 as its brake,” says Hegemann.

    While the PS is moving across the cell membrane and looking for a stronger chemical signal, only a few molecules of the breaking protein Cdc24 are present in the machinery. Once it has found the signal’s maximum concentration, the PS requests additional Cdc24 molecules, which are stored in the nucleus, to bind to the complex. The more Cdc24 molecules that attach to the PS machine, the slower it becomes. However, only when Cdc24 numbers exceeds a certain threshold does the PS stop completely and start the bulge formation in the cell.

    An important foundation stone

    “First, we observed the polarity site’s movement using the fluorescence microscope. Then we simulated this movement on the computer, which allowed us to develop a hypothesis for how the movement could be controlled. We were then able to confirm this hypothesis experimentally through mutations and using the fluorescence microscope,” says Hegemann, who is pleased with the new findings. He says the relatively simple computer model provided an excellent basis for planning the experiments by enabling the researchers to change the components rapidly and thereby identify important aspects. This made the study simpler, he says, as it was not necessary to test everything experimentally.

    Hegemann assumes that it’s not only yeast cells that use a multitool resembling the polarity site. Behaviour similar to that of a PS has also been observed in fission yeast (S. pombe) and the roundworm (C. elegans), albeit with no molecular explanation. The ETH researchers have now provided this explanation and described in detail for the first time how cells can locate a scent gradient. This work lays an important foundation stone for further studies on spatial signal perception by cells – both in yeast and in humans. According to Hegemann, currently no direct medical applications are envisaged: “In the distant future, this work might well benefit the general public. At the moment, however, it primarily represents an important advance for fundamental research.”

    Reference

    Hegemann B, Unger M, Lee SS, Stoffel-Studer I, van den Heuvel J, Pelet S, Koeppl H, Peter M. A Cellular System for Spatial Signal Decoding in Chemical Gradients. Developmental Cell, Volume 35, Issue 4, 23 November 2015, Pages 458–470. DOI: 10.1016/j.devcel.2015.10.013

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

     
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