Tech

The storm that became Typhoon Lingling strengthened very quickly in the Northwestern Pacific Ocean and infrared imagery from NASA revealed the powerful thunderstorms fueling that intensification.

Lingling formed on Sept. 2 as Tropical Depression 15W and strengthened quickly into a tropical storm and then a typhoon.  Although Lingling is to the northeast of Luzon, northern Philippines, there are still some warning signals in effect on Sept. 3. Tropical cyclone wind signal #1 is in effect over the Luzon province of Batanes.

On Sept. 3 at 12:05 p.m. EDT (1405 UTC), the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Terra satellite used infrared light to analyze the strength of storms within the typhoon. NASA researches these storms to determine how they rapidly intensify, develop and behave.

Tropical cyclones are made of up hundreds of thunderstorms, and infrared data can show where the strongest storms are located. They can do that because infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures.

MODIS found those strongest storms were northeast and southeast of the center of circulation where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). NASA research has found that cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

At 11 a.m. EDT (1500 UTC), the Joint Typhoon Warning Center or JTWC said that Typhoon Lingling, known locally in the Philippines as Liwayway was located near 21.4 degrees north latitude and 124.2 degrees east longitude. That is 364 nautical miles southwest of Kadena Air Base, Okinawa, Japan. Lingling was moving to the north and had maximum sustained winds near 65 knots (75 mph/120.3 kph).

JTWC forecasters said that Lingling is moving north and is expected to intensify to 100 knots (115 mph/185 kph) upon passing east of Taiwan. The system will then weaken on approach to the Korean peninsula, but still be at typhoon strength.

The Global Precipitation Measurement mission or GPM core satellite provided a look at rainfall rates in Tropical Depression Kajiki after it made a quick landfall in Vietnam.

On Sept. 2, Kajiki formed as Tropical Depression 16W in the South China Sea close to the Vietnam coast. It briefly strengthened to a tropical storm and was renamed Kajiki before weakening back to depression status.

The GPM satellite passed over the South China Sea and analyzed the rain rates throughout the storm on Sept. 3 at 4:51 a.m. EDT (0851 UTC). GPM found the heaviest rainfall in areas over central Vietnam and Laos, where it was falling at a rate of 20 mm (about 0.8 inch) per hour. Lighter rainfall rates around those areas was between 0.2 and 0.4 inches (5 and 10 mm) per hour. Light rain was also falling over Hainan Island, China. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA. NASA researches tropical cyclones and provides data to international partners to use in their forecasting.

At 11 a.m. EDT (1500 UTC), Tropical Depression Kajiki had maximum sustained winds near 30 knots (34.5 mph/55.5 kph). It was centered near 16.3 degrees north latitude and 107.4 degrees east longitude, about 55 nautical miles west-northwest of Da Nang, Vietnam.

The Joint Typhoon Warning Center noted that Kajiki made landfall into Vietnam, but will move back out over water. The system is forecast to dissipate within a day or so.

Social network interventions can have a significant effect on a range of health behaviors and outcomes both in the short and long term, according to a new study published this week in PLOS Medicine by Ruth Hunter of Queen's University Belfast, UK, and colleagues.

There has been a growing interest in understanding the effects of social networks on health-related behaviors and on the optimal way to apply social network approaches to health interventions. In the new study, researchers conducted a systematic review and meta-analysis of 37 studies, including 27 randomized controlled trials, investigating the effectiveness of social network interventions for health behaviors and outcomes. The studies were conducted between 1996 and 2018, originated in 11 countries, and included a total of 53,891 participants. Outcomes included sexual health behaviours, substance abuse, smoking cessation, diet, physical activity, weight loss and vaccinations.

The researchers found that significant effects of social network interventions on sexual health outcomes (odds ratio 1.46, 95% CI 1.01-2.11) were supported by the most evidence, but there were also statistically significant effects for interventions on alcohol misuse, wellbeing, change in a diabetes marker, and smoking cessation. Effects were seen in both the short term (6 months). Intervention effects for drug risk outcomes were not significant. Overall, 22 of the 37 studies that were included had a high risk of bias, and many were limited by their reliance on self-reported outcomes. However, they also demonstrated high participation and retention rates that have the potential to reach at-risk populations.

"We recommend that the scientific community should move beyond individual-level approaches, to design and test interventions that use the largely untapped potential of social networks to improve health behaviors and outcomes," the authors say.

Electric solid propellants are being explored for use in dual-mode rocket engines because they aren't susceptible to ignite from a spark or flame and can be turned on and off electrically.

Researchers from the University of Illinois at Urbana-Champaign, Missouri University of Science and Technology, and NASA conducted experiments to understand the behavior of a high-performance electric propellant compared with a traditional propellant.

"Electric solid propellants have been studied as chemical rocket propellants, but what we focused on is studying these types of propellants for electric propulsion systems--so, not the fire, smoke, and combustion you see in chemical rocket engines but for in-space electric pulsed plasma thrusters," said Joshua Rovey, associate professor in the Department of Aerospace Engineering in The Grainger College of Engineering at the U of I.

Rovey explained that in electric engines, there is a high-temperature plasma right next to the surface of the electric solid propellant. A small amount of that surface vaporizes and gets expelled out at high speeds. That's called ablation.

"Learning about the amount of ablation can allow us to better assess how it might perform as a propellant in an electric rocket engine, and better assess its lifetime," Rovey said.

Rovey said the application for dual-mode or multimode rocket engines is that there could be one rocket engine with one propellant that can operate in the chemical mode with high thrust, or you can operate it in an electric mode, in which a very fast electric pulse ablates the surface off of the material, and provides very high performance.

In the experiment, a high-performance electric propellant, manufactured by Digital Solid State Propulsion was compared with polytetrafluoroethylene, a traditional propellant used in ablative pulsed plasma thrusters. The space and high-altitude vacuum facility in the Aerospace Plasma Lab was used to conduct the tests. The propellant samples were measured before and after testing to determine how much of the propellant comes off of the surface with each electric pulse.

The results indicate that the electric solid propellant ablates about two times more than the traditional propellant and that the physics of the high-temperature ablation-fed arc discharge is similar for both propellants.

Rovey said, in addition to rocket engines, electric solid propellants can be used as a safer explosive in mines and pyrotechnics because it only ignites with an electrical signal.

With warming temperatures, average snowfall frequency is estimated to decline across the Pacific Northwest by 2100 -- and at a faster rate if greenhouse emissions are not reduced, according to a new Portland State University study.

Researchers in PSU's Climate Science Lab -- postdoctoral scholar Arielle Catalano, geography professor and climate scientist Paul Loikith and graduate student Christina Aragon -- looked at projected change in the number of snow days versus rain days at 157 SNOTEL stations in Oregon, Washington and Idaho. SNOTEL, or snowpack telemetry network, sites are often used to monitor water availability in mountainous regions and provide an observational baseline for defining snowfall. Using climate model projections, changes in the ratio of snow days to rain days are estimated relative to observations at these stations.

Catalano said that calculating changes at locations used for monitoring snowfall across the mountainous Northwest can provide information at scales relevant to those monitoring and managing water resources.

In the Northwest, snowpack acts as a natural reservoir, recharging groundwater and providing water throughout the drier summer months. Snowfall impacts water supply, which can affect agriculture, wintertime flooding and recreational activities such as skiing and boating.

"These snow-dominated regions are going to start to see an increasing proportion of precipitation falling as rain," Catalano said. "This gives us a sense of the site-specific changes in time and space, what's going on in this region, and what we can expect to see on average in terms of snow versus rain days over time."

Among the study's findings, published in the journal Geophysical Research Letters:

By the end of the 21st century, over 90% of SNOTEL stations across the Northwest will continue to receive snow, but many of these locations will experience more than half of wet days as rain, meaning more precipitation will fall as rain instead of snow.

Snowfall frequency declines are largest at low- and mid-elevation sites like the Cascades

Catalano said global efforts to mitigate greenhouse gas emissions can slow the rate of decline. At virtually all of the stations, business-as-usual emissions would lead to a faster rate of decline throughout the second half of the 21st century, whereas mitigating emissions results in slowing rates.

"Overall snowfall frequency would still be declining, but at a slower rate," Catalano said.

Another Atlantic Ocean basin depression formed while Hurricane Dorian is still wreaking havoc on the Bahamas and affecting the southeastern U.S. Infrared imagery from NASA's Aqua satellite shows that Tropical Depression 7 in the western Gulf of Mexico has developed powerful thunderstorms with heavy rain capabilities. That potential for heavy rainfall includes southern Texas and northeastern Mexico.

NASA conducts research on tropical cyclones and provides various data to forecasters at NOAA's National Hurricane Center (NHC) to consider in their forecasts.

 NASA's Aqua satellite used infrared light to analyze the strength of storms in Tropical Depression 7 and found strongest storms in fragmented bands of thunderstorms north and south of the center. The westernmost extent of those strong storms were already affecting the extreme northeastern coast of Mexico. Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.

On Sept. 3 at 4:30 a.m. EDT (0830 UTC) the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite found strongest thunderstorms had cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

The NHC said the system is expected to produce the following rainfall totals through Friday:

In northeastern Mexico, 6 to 12 inches of rainfall is possible with isolated totals to 15 inches, highest in the Sierra Madre Oriental of Tamaulipas and Nuevo Leon. This rainfall may cause life-threatening mudslides and flash floods. In south Texas and the lower Texas Coast, 2 to 4 inches are possible with isolated amounts as high as 6 inches.

Tropical Depression 7 (TD7) formed around 5 a.m. EDT today, Sept. 3, 2019 and NHC posted a Tropical Storm Warning from La Pesca to Barra El Mezquital, Mexico.

NHC's advisory at 11 a.m. EDT (1500 UTC) on Sept. 3 noted that the center of Tropical Depression Seven (TD7) was located near latitude 23.6 degrees north and longitude 94.9 degrees west.  The depression is moving toward the west near 7 mph (11 kph), and this motion is expected to continue today.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Slow strengthening is forecast before the system moves inland, and the depression is expected to become a tropical storm by Wednesday. The estimated minimum central pressure is 1004 millibars.

NHC forecasters said a motion toward the west-northwest is forecast tonight and Wednesday.  This motion could bring the system near or over the coast of northeastern Mexico late Wednesday.

In the early hours of Tuesday, September 3, Hurricane Dorian had been stationary over the island of Grand Bahama for 18 hours, most of the time as a category 5 hurricane. Storm-total rain accumulation over parts of Grand Bahama and Abaco Islands have exceeded 24 inches according to NASA satellite-based estimates.

On early Tuesday morning, Dorian's central pressure had risen and its wind intensity had dropped to category 4 on the Saffir-Simpson scale.  In addition, Dorian had experienced an eyewall replacement cycle on September 2, so by Tuesday morning Sept. 3, the geographic extent of its tropical-storm-force winds had expanded.

These rain estimates come from the NASA IMERG algorithm, which combines observations from a fleet of satellites, in near-realtime, to provide global estimates of precipitation every 30 minutes. The storm-total rainfall at a particular location varies with the forward speed of the hurricane, with the size of the hurricane's wind field, and with how vigorous the updrafts are inside of the hurricane's eyewall.

IMERG, or the Integrated Multi-satellitE Retrievals for GPM (IMERG) data product is generated by NASA's Precipitation Processing System every half hour with a 6 hour latency from the time of data acquisition. It is produced using data from the satellites in the GPM or Global Precipitation Measurement mission constellation of satellites, and is calibrated with measurements from the GPM Core Observatory as well as rain gauge networks around the world.

IMERG is an example of the research role that NASA has in hurricanes  - developing observational tools and building computer models to better understand the behavior of tropical cyclones. NASA's research data is utilized by NOAA's National Hurricane Center (NHC) to enhance their forecasts.

On Tuesday, September 3, 2019, at 8 a.m. EDT (1200 UTC), NHC reported at the eye of Hurricane Dorian was located by reconnaissance aircraft and NOAA Doppler radar near latitude 27.1 degrees North and longitude 78.4 degrees West. NHC said Dorian is beginning to move northwestward at about 1 mph (2 kph), and a slightly faster motion toward the northwest or north-northwest is expected later today and tonight.

At present maximum sustained winds are near 120 mph (195 kph) with higher gusts.  Dorian is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Dorian is expected to remain a powerful hurricane during the next couple of days. Hurricane-force winds extend outward up to 45 miles (75 km) from the center, and tropical-storm-force winds extend outward up to 160 miles (260 km). The latest minimum central pressure reported by reconnaissance aircraft is 952 mb (28.11 inches).

NHC forecasts a turn toward the north by Wednesday evening, followed by a turn to the north-northeast Thursday morning.  On this track, the core of extremely dangerous Hurricane Dorian will gradually move north of Grand Bahama Island through this evening. The hurricane will then move dangerously close to the Florida east coast late today through Wednesday evening, very near the Georgia and South Carolina coasts Wednesday night and Thursday, and near or over the North Carolina coast late Thursday.

Bottom Line: The U.S. Preventive Services Task Force (USPSTF) added aromatase inhibitors to its recommendation that clinicians offer medications to reduce the risk of breast cancer (tamoxifen, raloxifene or aromatase inhibitors) to asymptomatic women 35 and older, including those with previous benign breast lesions, who are at increased risk of developing the disease but at low risk for adverse effects from the medications. The USPSTF recommends against routine use of these medications in women not at increased risk for breast cancer. This recommendation doesn't apply to women who have a current or previous diagnosis of breast cancer or ductal carcinoma in situ. This statement is an update of its 2013 recommendation.

(doi:10.1001/jama.2019.11885)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Note: More information about the U.S. Preventive Services Task Force, its process, and its recommendations can be found on the newsroom page of its website.

Bottom Line: This observational study looked at patterns of use for computed tomography (CT), magnetic resonance imaging (MRI), ultrasound and nuclear medicine imaging in the United States and in Ontario, Canada, from 2000 to 2016. Medical imaging use increased rapidly from 2000 to 2006 and this analyzes its use in more recent years among 16 million to 21 million patients enrolled in seven U.S. health care networks and for patients in Ontario, Canada. The analysis included 135 million imaging examinations. Among adults over 18, imaging rates were higher in 2016 compared with 2000 for all types except nuclear medicine, which has declined in use among adults and children since 2006. Among children, imaging rates continued to increase except for CT, which has declined since 2006. Limitations of the study include U.S. patients enrolled in health care systems that used HMO models of care, which may not represent imaging use among patients covered by other plans. Also, the reason for imaging wasn't available so it's impossible to know if the imaging was appropriate.

Authors: Rebecca Smith-Bindman, M.D., University of California, San Francisco, and coauthors

(doi:10.1001/jama.2019.11456)

Editor's Note: The article includes conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Plasmonic nanostructures have been widely used for enhancing light-matter interactions due to the strong local field enhancement in deep subwavelength volumes.

Localized surface plasmon resonances (LSPRs) and propagating surface plasmon resonances (SPR) both suffer from low quality factors and limited field enhancements, resulting in restricted performance in applications. By patterning metal nanoparticles in arrays, plasmonic surface lattice resonances (SLRs) can have lower radiation loss, higher quality factors, and larger field enhancements over large volumes.

A research group led by Dr. LI Guangyuan and Dr. LU Yuanfu from the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences reported a novel type of SLR based on metal-insulator-metal (MIM) arrays. The paper, entitled "Narrow plasmonic surface lattice resonances with preference to asymmetric dielectric environment," was published on Sep. 2 in Optics Express and was highlighted as an Editor's Pick.

Conventional SLRs are supported mainly by periodic metal nanoparticles and require a symmetric dielectric environment, that is, the superstrate and the substrate should have the same refractive index. If the dielectric environment becomes less symmetric, SLR performance deteriorates dramatically. This greatly hinders the practical applications of SLRs especially in optofluidic sensors, where it is difficult to match the refractive index of the substrate with water or other fluids.

In this work, the researchers proposed a new SLR supported by a periodic MIM array and with a higher quality factor in a less symmetric dielectric environment. They showed that when the dielectric environment was as asymmetric as the air/glass environment, the proposed SLRhad a high quality factor of 62 under normal incidence and 147 under oblique incidence in the visible regime, or several times the highest quality factors of conventional SLRs under the same conditions.

They also illustrated that an opto-microfluid sensing platform based on the proposed SLR under normal incidence (without optimization) had a sensitivity of 316 nm/RIU and a figure of merit (FOM) of 25. This FOM is much larger than that of conventional LSPR, SPR or SLR sensors.

The researchers believe that the SLR they have proposed, featuring higher quality factors in a less symmetric environment, is appealing for diverse applications, including nanolasers, nonlinear optics, ultrasensitive sensing, and modulators.

Prospective digital data storage devices predominantly rely on novel fundamental magnetic phenomena. The better we understand these phenomena, the better and more energy efficient the memory chips and hard drives we can build. Physicists from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the Helmholtz-Zentrum Berlin (HZB) have now completed the essential fundamental work for future storage devices: Using a creative approach of shaping magnetic thin films in curved architectures, they validated the presence of chiral responses in a commonly used magnetic material. This facilitates the creation of magnetic systems with desired properties that rely on simple geometrical transformations. The team has now presented their work in the journal Physical Review Letters (DOI: 10.1103/physrevlett.123.077201).

We all know that our left hand is different from our right - a left glove won't fit your right hand and vice versa. Scientists use the term "chirality" to describe objects that do not align with their mirror image. Chemists, in particular, are familiar with this property in molecules, as in left- and right-rotating lactic acid. Humans metabolize the right-rotating variant more easily than its "mirror image".

Such chiral effects are known to occur in magnetic materials, where magnetic textures also have chiral properties: the arrangement of individual magnetic moments inside the material, or, figuratively speaking, the alignment of the many tiny "compass needles" that make up a magnet, could form right- and left-handed alignments. Under certain conditions, some textures behave like image and mirror image - a left-handed texture cannot be made congruent with its right-handed version.

The interesting aspect here is that "the two textures can present different magnetic behaviors," as HZDR physicist Dr. Denys Makarov points out. "To put it simply: a right-handed texture can be more energetically preferable than a left-handed texture. Since systems in nature tend to assume their lowest possible energetic state, the right-handed state is preferred." Such chiral effects hold great technological promise. Among other things, they could be helpful in the future development of highly energy-efficient electronic components such as sensors, switches, and non-volatile storage devices.

Magnetic curved architectures

"Helimagnets are materials with well-defined chiral magnetic properties, due to a lack of internal magnetic symmetry," explains the lead author of the paper, Dr. Oleksii Volkov from HZDR's Institute of Ion Beam Physics and Materials Research. "Despite the fact that they have been known for a long time, these are rather exotic materials that are difficult to produce. Moreover, helimagnets usually exhibit their unique chiral properties at low temperatures." That is why Makarov's team chose a different path. They used a common magnetic material, iron-nickel alloy (known as Permalloy), to build curved objects like parabola-shaped strips. Using lithography, they formed various parabolic strips of several micrometers from thin sheets of Permalloy.

The physicists then exposed the samples to a magnetic field, thus orienting the magnetic moments in the parabola along this magnetic field. They then experimentally explored the magnetization reversal by using a highly sensitive analysis method at HZB's synchrotron. The team was able to show that the magnetic moments in the parabolic strip remained in their original direction until a reversed magnetic field of a certain critical value was applied.

Surprisingly strong effect

This delayed response is due to chiral effects caused by the curvature at the apex area of the parabola strips. "Theorists have predicted this unusual behavior for some time, but it was actually considered more of a theoretical trick," explains Dr. Florian Kronast of Helmholtz-Zentrum Berlin. "But now we have shown that this trick actually works in practice. We detected magnetic chiral response in a conventional soft ferromagnetic material, just through the geometric curvature of the strips we used."

In the process, the team were faced with two more surprises: On the one hand, the effect was remarkably strong, which means it could be used to influence the magneto-electric responses of materials. On the other hand, the effect was detected in a relatively large object: micrometer-sized parabolas that can be produced using conventional lithography. Previously, experts had assumed that these curvature-induced chiral effects could only be observed in magnetic objects with dimensions of about a dozen of nanometers.

"In terms of possible applications, we are looking forward to novel magnetic switches and data storage devices that utilize geometrically-induced chiral properties," Makarov emphasizes. There are concepts that envision future digital data storage in certain magnetic objects, so-called chiral domain walls or skyrmions. The recent discovery might help to produce such objects quite easily - at room temperature, and using common materials. In addition, the newly discovered effect also paves the way for novel, highly sensitive magnetic field sensors.

Quantum information relies on the possibility of writing messages in a quantum particle and reading them out in a reliable way. If, however, the particle is relativistic, meaning that it moves with velocities close to the speed of light, it is impossible for standard techniques to unambiguously decode the message and the communication fails. Thanks to the introduction of a new method to write and read the message researchers at the University of Vienna and the Austrian Academy of Sciences guarantee the reliable decoding of quantum messages which are transmitted extremely fast. The result published in the journal PRL opens up new possibilities of technological applications in quantum information and quantum communication.

Let us imagine the following situation: Anna and Bill want to communicate exchanging a message by using a property of a quantum particle, say the spin of an electron, which is an intrinsic form of particle's rotation. Bill needs Anna's message as quickly as possible, so Anna has to send the electron at maximum speed, very close to the speed of light. Given that Anna has the electron in her laboratory localized, one of the fundamentals of quantum physics, the Heisenberg uncertainty principle, forbids the velocity of the electron to be defined with arbitrary precision. When the electron travels extremely fast, that means, relativistically, the interplay between special relativity and quantum physics causes the spin and the velocity of the electron to get entangled. Due to this correlation, which is stronger than what is classically possible, Bill is not able to read out the spin with the standard method. Can Anna and Bill improve their communication strategy?

A group of researchers led by ?aslav Brukner at the University of Vienna and the Institute for Quantum Optics and Quantum Information (IQOQI-Vienna) of the Austrian Academy of Sciences have introduced a novel alternative to the standard alphabet used by Anna and Bill. Their technique guarantees that the message, written by Anna and read by Bill, can be decoded unambiguously even when the particle behaves according to both quantum mechanics, because of Heisenberg's uncertainty principle, and special relativity, due to its very high velocity.

The novel method as presented in the journal Physical Review Letters delivers a new definition of the spin of quantum particles that move very fast. Thus it modifies both the way Anna writes the message and the way Bill reads it. Key to this technique is a "translation" of the way the message would be written and read between the standard alphabet, used when the electron is at rest, and the new alphabet, used when the electron travels very fast. "These results are indicative that this translation procedure could open up to new applications in relativistic quantum information," says Flaminia Giacomini, the lead author of the paper. For instance, this technique could be helpful in satellite-based quantum communication, where a particle carrying a message has to travel quickly between two far-away points.

Implantable defibrillators can save lives, but also harbor risks. A major European study headed by three researchers from the Technical University of Munich (TUM), LMU München and University Medical Center Göttingen has found that a special ECG method can help to identify the patients most likely to benefit from these devices. The results of the study have now been published in The Lancet.

In heart patients with potentially life-threatening arrhythmias, a strong electrical shock applied to the cardiac muscle can reset the heart to its regular rhythm. This is precisely the task of defibrillators, which are inserted into the chest like pacemakers. Under current guidelines, physicians implant these devices as a preventive measure in patients with certain heart conditions. The procedure is performed more than 100,000 times per year in the EU. Apart from the high costs for the health care system, the devices also pose a risk: According to estimates, one in four implanted defibrillators will lead to significant complications within ten years - from infections to spontaneous electric shocks.

The EU-CERT-ICD study therefore examined the benefits of prophylactically implanted defibrillators throughout Europe. In a sub-study of the EU-CERT-ICD project, the scientists led by first author Prof. Axel Bauer (formerly LMU and currently Medical University of Innsbruck) and the two co-senior authors Prof. Georg Schmidt (TUM) and Prof. Markus Zabel (University Medical Center Göttingen) wanted to identify the patients who benefit most from the operation.

PRD: an indicator of the electrical instability of the heart

Each heartbeat consists of a sequence of excitation (depolarization) and regression of excitation (repolarization). Heart failure often leads to overactivity of the sympathetic nervous system, a part of the autonomic nervous system that is active in stressful situations. This overactivity can destabilize the repolarization of the heart, resulting in a dramatic increase in the risk of damaging arrhythmias. These dangerous instabilities in repolarization can be recognized using a relatively new ECG procedure known as periodic repolarization dynamics (PRD). "Although the procedure involves intelligent algorithms, the measurements are relatively simple," explains Axel Bauer, who worked with Georg Schmidt to develop and validate the method.

In their prospective study, the scientists tracked 1,371 patients who met the current criteria for the implant of a defibrillator. Of the group, 968 actually underwent the operation, while the doctors treating the other 403 patients decided against a defibrillator.

High PRD value: indicative of benefits from an implantable defibrillator

The preventive implantation of a defibrillator resulted in an overall 43 percent decrease in mortality over the subsequent four-year period. For patients with a PRD value greater than or equal to 7.5 degrees, the reduction in the mortality risk was significantly larger, at 75 percent. For PRD values below 7.5 degrees, the mortality risk was reduced by only 31 percent. "PRD could become an important decision making tool for physicians," says Georg Schmidt, the head of the Biosignal Processing Working Group at TUM's Klinikum rechts der Isar. "With the additional information, patients who would probably not benefit from a defibrillator could be spared the risk of an implant. Instead we could focus on those whose lives would likely be extended by the device." The results will first have to be confirmed in further studies, however, before they can be included in medical treatment guidelines. "An important step, among others, would be to conduct a study over a longer period," says Markus Zabel, the head of the main EU-CERT study.

Researchers at the University of Göttingen have developed a new method that takes advantage of the unusual properties of graphene to electromagnetically interact with fluorescing (light-emitting) molecules. This method allows scientists to optically measure extremely small distances, in the order of 1 ångström (one ten-billionth of a meter) with high accuracy and reproducibility for the first time. This enabled researchers to optically measure the thickness of lipid bilayers, the stuff that makes the membranes of all living cells. The results were published in Nature Photonics.

Researchers from the University of Göttingen led by Professor Enderlein used a single sheet of graphene, just one atom thick (0.34 nm), to modulate the emission of light-emitting (fluorescent) molecules when they came close to the graphene sheet. The excellent optical transparency of graphene and its capability to modulate through space the molecules' emission made it an extremely sensitive tool for measuring the distance of single molecules from the graphene sheet. The accuracy of this method is so good that even the slightest distance changes of around 1 ångström (this is about the diameter of an atom or half a millionth of a human hair) can be resolved. The scientists were able to show this by depositing single molecules above a graphene layer. They could then determine their distance by monitoring and evaluating their light emission. This graphene-induced modulation of molecular light emission provides an extremely sensitive and precise "ruler" for determining single molecule positions in space. They used this method to measure the thickness of single lipid bilayers which are constituted of two layers of fatty acid chain molecules and have a total thickness of only a few nanometers (1 billionth of a meter).

"Our method has enormous potential for super-resolution microscopy because it allows us to localise single molecules with nanometre resolution not only laterally (as with earlier methods) but also with similar accuracy along the third direction, which enables true three-dimensional optical imaging on the length scale of macromolecules," says Arindam Ghosh, the first author of the paper.

"This will be a powerful tool with numerous applications to resolve distances with sub-nanometer accuracy in individual molecules, molecular complexes, or small cellular organelles," adds Professor Jörg Enderlein, the publication's corresponding author and head of the Third Institute of Physics (Biophysics) where the work took place.

Europe has enough solar and wind resources to meet its electricity demand entirely from renewable sources. A new study by researchers at the Institute for Transformative Sustainability Research (IASS) in Potsdam shows that many regions and municipalities could meet their electricity demand using electricity systems based exclusively on renewables. However, their development would exacerbate land use pressure around metropolitan areas and larger conurbations.

The findings of the study are presented online on an interactive map covering Europe's regions and cities. Users can simply zoom into a region or village - from Landau in Germany's Rhineland-Palatinate region to Berlin, and from Menton on the French Riviera to the Italian capital of Rome - the map identifies the potential for electricity generation from renewables across Europe and reveals whether regions could meet their electricity demand from renewable sources.

"Our results show how difficult it is, especially in the case of densely populated cities such as Berlin, to meet electricity demand from renewable energy sources," explains lead author Tim Troendle - "but the technology is now sufficiently advanced that even this would be feasible if metropolitan areas were to join forces with their surrounding regions." Rural regions and urban areas with extensive rural hinterlands could meet their electricity demand entirely from renewable sources: at the local level, 75 percent of municipalities can access sufficient solar and wind resources to meet their annual electricity demand.

Achieving electricity autarky across four administrative levels

Developing a self-sufficient, regenerative electricity supply requires the availability of sufficient open surfaces or land that could be used for energy generation. As part of their research for the study, the scientists collated data to identify eligible areas and surfaces and determine renewable electricity yields at the continental, national, regional and municipal levels.

Led by Professor Johan Lilliestam, the authors from the IASS and ETH Zurich determined the technical potentials of roof-mounted and ground-level photovoltaic systems as well as onshore and offshore wind turbines by analysing the availability and eligibility of land areas. Their analysis takes into account current land cover and land use by towns as well as agricultural use and included altitudes and local climatic conditions, which could limit electricity generation from renewable sources. This enabled the researchers to determine potential electricity yield, taking into account the technical constraints.

But if future energy systems are to be sustainable and enjoy broad acceptance across society, they will not be able to exploit their full technical potential. To reflect this, the researchers excluded certain areas such as nature reserves and arable land, where energy infrastructure would harm the landscape or prevent agricultural activities. Data on electricity consumption from 2017 were used to gauge demand. In line with previous analyses, the authors were able to demonstrate that the technical and social potential of renewable electricity is greater than demand at continental and national levels. In order to also achieve electricity autarky at the sub-national level, however, regions would have to assign large shares and sometimes their entire undeveloped land to electricity generation from renewable energies, according to the study.

The prospects for Europe

If socio-technical constraints are applied, the total potential electricity output at the continental level is 15,000 TWh/a more than four times the current demand. Even when severe social constraints are applied, reducing the technical potential by over 90 percent, Europe could still potentially generate enough electricity from renewable sources to achieve electricity autarky at the continental level, and in each individual country.

At the regional and municipal levels, the authors see the lowest relative potential within city borders: For example, Oslo shows the lowest potential, as less than a quarter of the city's demand for electricity can be met through local energy generation from renewable sources. Other urban areas also lack sufficient technical and social potential, including the Ile-de-France (Paris), Dublin and Berlin. But these cities could achieve electricity autarky by cooperating with surrounding regions to form self-sufficient metropolitan regions. The study also shows, however, that the pursuit of local autarky can concentrate electricity generation in already densely populated areas - an outcome that may or may not be desirable and which regions would need to consider.

"Ultimately, it is a balancing act between self-sufficiency and more intensive local land use on the one hand and the acceptance of imports together with greater cooperation with other municipalities, regions and countries in Europe on the other," says Troendle. But in principle, 100% renewable electricity self-sufficiency is possible on all administrative levels from continental to regional, and often even on the municipal level, especially if mechanisms for electricity trading between regions and countries can be established.