Tech

ST. LOUIS, MO, February 16, 2021 - Delivering the benefits of agricultural biotechnology to smallholder farmers requires that resources be directed toward staple food crops. To achieve effect at scale, beneficial traits must be integrated into multiple, elite farmer-preferred varieties with relevance across geographical regions. For the first time, an international team of scientists, led by Narayanan Narayanan, Ph.D., senior research scientist, and Nigel Taylor, Ph.D., associate member and Dorothy J. King Distinguished Investigator at the Donald Danforth Plant Science Center, and their collaborators in Nigeria, led by Ihuoma Okwuonu, Ph.D., of the National Root Crops Research Institute, in Umudike, Nigeria and the United States Department of Agriculture, have developed cassava displaying high-level resistance to cassava mosaic disease (CMD), cassava brown streak disease (CBSD) as well as higher levels of iron and zinc. This is the first time that disease resistance and multiple biofortification traits have been stacked in this manner in a non-cereal crop. The results of their research, Stacking disease resistance and mineral biofortification in cassava varieties to enhance yields and consumer health, were recently published in Plant Biotechnology Journal. Co-authors include Getu Beyene, Ph.D., Raj Deepika Chauhan, of the Danforth Center and Michael A. Grusak, Ph.D., of the USDA-ARS Red River Valley Agricultural Research Center in Fargo, ND.

The research builds on a 2019 paper, Biofortification of field-grown cassava by engineering expression of an iron transporter and ferritin, published in Nature Biotechnology, demonstrating that increasing the mineral content of cassava storage roots was possible. RNAi-mediated technology was used to achieve resistance to CBSD in two East African and two Nigerian farmer-preferred cultivars along with AtIRT1 (major iron transporter) and AtFER1 (ferritin) transgenes to achieve nutritionally significant levels of iron and zinc in cassava storage roots (145 and 40 μg/g dry weight, respectively). The inherent resistance to CMD was maintained in all four disease resistant and mineral enhanced cassava cultivars, demonstrating that this technique could be deployed across multiple farmer-preferred varieties to benefit the food and nutritional security of consumers in Africa.

Combining technologies was not easy. "Production of plants with disease and elevated mineral nutrition concentration was technically more challenging to produce than for disease alone," said Narayanan, who has been working on improving cassava for 15 years. "We had to make sure the minerals were accumulated in the storage root, not the stem or leaves, and at the right level for consumers. Too much accumulation is also a problem as this will kill the plant."

It is important to confirm that the higher mineral levels are retained during food processing and cooking so that better nutrition can actually reach the dinner plate and the digestive tract. The research team under the direction of Okwuonu, prepared gari and fufu. These two common West African foods required a four-day process involving chopping, soaking, fermenting, pressing and roasting of the cassava root. They found that high levels of iron and zinc were retained through cooking and remained available for absorption in the gut following digestion. Ultimately, the biofortified cassava could benefit health in cassava consuming populations by providing 40-50 percent of Estimated Average Requirements (EAR) for iron and 60-70 percent of EAR for zinc for children and women in West Africa.

"To see these results of using cutting-edge technology to improve an orphan crop was a big day for me," said Taylor. "Farmers that have cassava plants that are resistant to two incredibly destructive diseases with more minerals in every bite has the potential to improve the nutrition and health of millions of people in West Africa."

In an accompanying paper recently published in Global Food Security, Okwuonu and her coauthors present, Opportunities and challenges for biofortification of cassava to address iron and zinc deficiency in Nigeria. The country is the world's largest producer of cassava and it is critically important to the economy. Cassava's edible storage roots act as a critical staple food for more than 180 million Nigerians. Though high in caloric value, cassava roots are deficient in minerals, placing populations that rely on this crop at risk of "hidden hunger". Micronutrient deficiency presents a major public health issue and correlates with cassava consumption level across six-agro-ecological zones within Nigeria. Micronutrient deficiencies, especially iron and zinc, affect an estimated six million children under five years of age. Iron deficiency anemia affects their immune system, stunts growth and impairs cognitive development, while deficiency in zinc causes increased risk of death from diarrhea, stunting and reduced cognitive development. Co-lead authors on the paper are Narayanan N. Narayanan, Chiedozie N. Egesi, and Nigel J. Taylor.

"Developing a cassava variety with elevated levels of iron and zinc for consumption in Nigeria has the potential to ensure that the wider population of Nigerians dependent on cassava are indeed getting greater nutritional value in their diets," said Okwuonu.

Researchers in the VIRCA Plus project are conducting more field evaluations and assessments. Regulatory review will be needed before the improved cassava can be made available to farmers and consumers in the coming years.

An international team of researchers has solved a puzzling phenomenon whereby strangely beautiful, vortex-like structures appear between materials deposited onto engineering components used in multiple settings - from space shuttles to household items and everyday transport vehicles.

The discovery may ultimately improve the efficiency of the "Cold Spray" (CS) deposition process from which these structures are formed - a not-insignificant consideration from a financial perspective, or from a functional one given that some of the materials created by CS are pushed to the limit in outer space.

The discovery is featured on the front cover of international journal, Materials & Design.

Cold Spray (CS) and deposition efficiency (DE)

CS enables the formation of coatings, typically metallic, over a substrate material. The technique is highly useful as it does not require engineers to reach the melting temperature of materials to combine the coatings and substrates.

Particles (or metal powder) with a typical diameter about ½ the size of a human hair are propelled at supersonic speeds via an accelerating gas over a substrate surface.

Plastic deformation is key in this process; each tiny particle deforms on impact and triggers a complex bonding process that results in substrate adhesion and in particle-particle adhesion after a first deposition layer is formed.

However, not all the particles adhere. The deposition efficiency (DE) measures the ratio of deposition vs rebound. For example, a DE of 50% means only 50% of the particles incoming flux have adhered to the coating zone.

Inefficiency in the process is a major hurdle given that it is an expensive technique, so increasing efficiency (and driving down costs) is a key research focus.

The vortex-like structures

For quite some time engineers have been observing strange, vortex-like structures at the interface location, between the coatings and the substrates. They are much smaller than the particles, which presented a puzzle: what are they and how do they form?

What's more, these structures don't always appear and, when they do, they show up in a rather random fashion.

Rocco Lupoi, Assistant Professor in Trinity College Dublin's School of Engineering, who is the work leader, teamed up with close colleagues and experts in China, the US, Czech Republic and with the Advanced Microscopy Laboratory (AML) in TCD to solve the puzzle.

He said:

"We discovered that the interface vortices only form when the CS process is not working very well, and thus has low DE values. Under low deposition efficiency, most of the sprayed particles rebound after their impact. By causing severe plastic deformation of the first-layer coating and substrate this results in a 'hammer effect', which leads to the formation of the vortices.

"This formation also depends on the coating-substrate material combination where the coating materials must have sufficiently high density to generate enough energy for creating large plastic deformation of the first-layer coating and substrate. Additionally, the substrate materials cannot be too hard so that plastic deformation can be induced onto it.

"Potentially, our discovery may help to improve the adhesion between the cold-sprayed coatings and the substrates. To benefit from this, while maintaining reasonable process economy, one could first create an intermixing interface through low-DE deposition, followed by production of the coating using optimised processing parameters."

Shuo Yin, Assistant Professor in Trinity's School of Engineering, who is the first author in the paper and the lead scientist in this work added:

"This was a great multi-disciplinary effort and has shed some light into a phenomenon that had puzzled the community for some time. The CS process does not function via the melting of the feedstock material, which is advantageous because it means there are limited to no-heat-affected zones, microstructural changes, or distortions to worry about on the end-products.

"Despite progress, CS remains a process under development, so part of our work is focused on improving the deposition performance, coating quality and substrate-coating bond strength. We hope this discovery opens the door to further improvements on that front."

"Thin films are solid state substances that can be only several atomic layers thick. Usually, their properties are considerably different from the properties of the original substances on the macroscale. The areas of their application keep expanding and include nanoelectronics, optoelectronics, spintronics, electro-, and photocatalysis, as well as such important fields of economics as space technologies and instrument building. Micromodule devices for space crafts and medical technologies are also promising areas in which thin films can be used," said Vyacheslav Fominski, a project supervisor representing MEPhI.

To reduce friction and solve many other issues, one could use metal chalcogenides, i.e. compounds of transition metals with sulfur, selenium, and tellurium. The first experiments aimed at obtaining thin films from these materials began in the 1980s. Then, the researchers were especially interested in the ability of the films to modify their properties when their structure or layer thickness changed. In their recent study, the Russian team studied the films that consisted of four elements: molybdenum, sulfur, carbon, and hydrogen. First, the team used laser impulses (dozens of nanoseconds duration) aimed at carbon and molybdenum targets to create plasma flows of these materials. When carbon and molybdenum transformed into the gas phase, they reacted with hydrogen sulfide pumped in the experimental chamber, and the product of the reaction deposited on a steel base. During this process, chemically active atoms of sulfur and hydrogen were able to get inside the growing coating. Together, the atoms formed a thin film on the metal. The properties of the film depended on the concentration of components and the mode of laser-plasma flow generation.

This method is called reactive pulsed laser deposition and provides for more smooth and dense layers. It also allows scientists to change different experiment parameters thus affecting the structure of the final products. This powerful tool for creating unique nanostructures is being actively developed in many research centers, including MEPhI and BFU.

The thin films obtained by the team were not more than 0.5 um thick but reduced friction by over 10 times: the friction factor of a steel ball sliding along a steel plate in the absence of any traditional liquid lubricating oils never exceeded 0.03 (at normal conditions and -100°?). This is the same factor that skates have on ice.

The study that included the development of coating technology, obtaining experimental samples, and measuring their characteristics was carried out under the supervision of Vyacheslav Fominski (MEPhI) under RSF support. The analytical part of the research was carried out at BFU under the supervision of Petr Shvets in the framework of a state order.

Cataracts are the most common eye ailment in humans. However, the exact processes leading to this condition are not fully understood. A team of researchers headed by the Technical University of Munich (TUM) has now discovered that the composition of the protein solution plays a decisive role. Their conclusions are contrary to prevailing opinion in the field.

The cells in the lens consist of a highly concentrated protein solution that is normally clear. "When the balance of the proteins in the lens is destroyed, they clump together and the lens becomes cloudy," says Prof. Johannes Buchner of the Chair of Biotechnology at TUM. This results in the condition known as cataracts.

The clouding can have different causes. Because the proteins in the lens are formed in the embryo and are not replaced, damage can accumulate over the years, ultimately causing the lens to cloud over. That is why cataracts occur mainly in older people. But some individuals have a genetic predisposition to the eye condition, in which proteins in the lens mutate. In these cases, cataracts are present at birth or appear during childhood.

Unstable proteins eliminated immediately

The scientists studied strains of mice affected by hereditary cataracts. They worked with the research group surrounding Jochen Graw, an expert in eye lenses who until 2019 was a professor at the Institute of Development Genetics at Helmholtz Zentrum München.

Until now, the prevailing view said that only the defective proteins in the eye were reacting with one another and forming clumps. But Buchner's team has now shown that, in the mice with "genetic cataracts", this was not the case. "We discovered that the mutated, unstable proteins in the lens were not there," says Buchner. "They are eliminated immediately." Instead the 'healthy' proteins clump together. "Our model, based on these new insights, says that the balance between the various proteins, or their ratios to one another, is important. When one of these components is missing, the remaining ones interact and form clumps."

Important step for cataract treatment

Many studies have been carried out to understand the causes of cataracts. "But never before has there been such a comprehensive investigation of the lenses in mice, comparing wild populations and mutants," says Buchner. The new insights are an important step in the search for new treatment methods for cataracts. The most common method is surgery, in which artificial lenses are implanted in the eye.

"If you understand exactly what is happening, you can also think about ways that might use medication to disrupt the bad interactions," says Buchner. "But we have a long way to go - and first we need to show that the proposed model also applies to the lens in the human eye."

The 'sloshing' of a quantum fluid comprised of light and matter reveals superfluid properties.

An Australian-led team of physicists have successfully created sloshing quantum liquids in a 'bucket' formed by containment lasers.

"These quantum fluids are expected to be as wavy as the oceans, but catching clear pictures of the waves is an experimental challenge," says lead author Dr Eliezer Estrecho.

Led by the Australian National University (ANU), the team serendipitously observed the wavy motion of the quantum fluid in an optically-controlled bucket, gaining new insights of the intriguing superfluid properties of this peculiar, hybrid light-matter system.

Superfluidity is the flow of particles without suffering resistance, and is pursued by FLEET researchers for future applications in ultra low-energy electronics.

FILLING THE BUCKET WITH THE QUANTUM FLUID LED TO SLOSHING

The team performed the experiments in a laser-made 'bucket' that traps particles called exciton-polaritons, which are hybrid light-matter particles in a semiconductor.

As these particles cool down they form a giant quantum object called a Bose-Einstein condensate (sometimes referred to as the fifth state of matter), in which quantum phenomena can be seen on a macroscopic scale.

"The excess energy lost by the cooling particles does not disappear easily so the condensate will display some sort of wavy behaviour, which is random for every realisation of the condensation," says corresponding author Prof Elena Ostrovskaya.

That randomness makes it hard to detect the transient oscillations with the imaging cameras, since it will average out in the experiment.

However, fortuitously, the 'bucket' is tilted.

"In most experiments, we try to avoid the tilt since it complicates the analysis," says Dr Estrecho.

"But in this case the 'annoying' tilt enabled the observation of the oscillation because it is favourable for the condensate to slosh along the tilt direction.

The sloshing oscillation was observed in both the position and momentum of the condensate, beautifully displaying the laws of quantum mechanics at a macroscopic scale that can be seen by an ordinary microscope. However, the oscillations are extremely fast, so that it was only possible to observe them using a camera with a picosecond-scale temporal resolution.

STUDYING THE SPEED OF SOUND IN SUPERFLUIDS

The true beauty of the experiment lies in the analysis of the oscillation frequencies since it is directly related to the speed of sound and can probe the superfluid properties of the quantum fluid. This is especially relevant since this peculiar quantum fluid can exist at room temperature, and hence is promising for device applications.

Using a clever analysis, the team has extracted the speed of sound from the experimental data, and found that it is smaller than expected from prevailing theories. The team argued that the discrepancy arises from the existence of an invisible reservoir of hot matter-like particles that interact with the hybrid light-matter particles.

Furthermore, the experiment also provides clues on the possible effects that can slow down the superfluid. At absolute zero temperature, the oscillations are expected to never end since the system is a superfluid. However, at finite temperature, this is not the case, so studying the damping rates of the oscillations is essential in understanding the superfluid.

Initial results show that neither the reservoir particles, finite temperature, or the inherent short lifetime of exciton-polaritons can solely explain the observed damping rates. Hence, further theoretical studies that combine these effects and carefully controlled experiments are needed to better understand the non-equilibrium quantum fluid.

Over the past years, global data traffic has experienced a boom, with over 12.5 billion connected devices all over the world. The current world-wide deployment of the 5G telecommunications standard is triggering the need for smaller devices with enhanced performances, such as higher speed, lower power consumption and reduced cost as well as easier manufacturability.

In search for the appropriate technology, photonic devices emerged as the leading technology for the evolution of such information and communication technologies, already surpassing the capabilities of current microelectronics and CMOS technologies.

Optical communication systems rely on three basic components: modulators, waveguides and photodetectors. The modulation of light is key for photonic integrated circuits because it allows to transmit multiple signals simultaneously over a single channel. More specifically, electro-absorption (EA) modulators modulate the amplitude of the light passing through the optical waveguide.

So far, silicon and graphene are winning the race since they are proving to be the most scalable, cost-effective and CMOS compatible materials for optical modulation and detection. Graphene-based modulators have already shown broadband optical bandwidth and temperature stability, but in occasions, they have been incapable of showing both high-speed and high modulation efficiencies simultaneously, due to the limited quality of graphene and a combination between the graphene and the dielectric material.

Now, in a study published in Nature Communications, ICFO researchers Hitesh Agarwal, Bernat Terrés, Lorenzo OrsinI, led by ICREA Professor at ICFO Frank Koppens, in collaboration with researchers from Universita di Pisa, CNIT, Ghent University-IMEC, and NIMS have reported on a novel EA modulator capable of showing a 3-fold increase in static and dynamic modulation efficiency while maintaining the high-speed, a value that surpasses those for previously reported graphene EA modulators.

To achieve this, the team of researchers developed a high-quality graphene-based electro-absorption modulator by combining high-quality graphene and a high-k dielectric, also used in microelectronics. The high quality of the graphene was achieved by integrating it with the 2d-material dielectric hexagonal boron nitride (hBN). Interestingly enough, the team was then able to add the high-k dielectric material HfO2 sandwiched in between two layers of boron nitride, which permitted operating with much smaller voltages, and, at the same time, achieving symmetric and hysteresis-free due to the high quality of the graphene. By doing this, the dielectric combination was able to enhance the EA modulator capacitance without compromising the robustness of the device against high voltages, preserve the high mobility of charge carries (increasing the modulation efficiency) while maintaining low levels of doping.

As Hitesh Agarwal, researcher at ICFO and first author of the study, comments, "Because one of the major bottlenecks for the integration of graphene into CMOS fab lines is its incompatibility with high-k oxides, this motivated us to build the structure of hBN-HfO2-hBN. Not only we managed to achieve high modulation efficiency (due to high-K dielectric), but also higher speed (due to increased mobility)."

"We have been waiting for a while to see the outstanding fundamental capabilities of graphene to unleash in applications", Bernat Terrés, Postdoc researcher at ICFO and corresponding author of the work, adds. He also stresses that "Optoelectronics is one of the first where this 2D material overcomes current state-of-the-art technologies, bringing an encouraging prospect for other commercial applications".

In summary, the device was capable of outperforming previous modulators, operating at high-speeds while, maintaining a very high modulation efficiency, low power consumption, achieving a record breaking 39GHz bandwidth, with operations up to 40Gbps speed, and consequently overcoming the fundamental limitations obtained so far with double layer graphene systems.

The compatibility of this device with silicon technology and microelectronics could facilitate the scaling improvements that we face nowadays for the photonic industry as well as implement this type of technology for a much greater range of functionalities in electronic and optoelectronic applications. Such results could definitely benefit applications for high-speed and low-latency optical networks such as autonomous vehicles, remote surgery, IoT, to name a few.

Collaborator of the study, Marco Romagnoli, researcher at CNIT and work-package leader of the Graphene Flagship, comments, "This new scientific result of ultrafast electro absorption modulator paves the way towards the continuous race for speed demonstrating the highest electro-optical bandwidth achieved with graphene and 2D materials. In addition, this work is also the first example of full 3D integration entirely realized by assembling different types of 2D materials demonstrating the potentiality of these new routes in microfabrication of integrated circuits."

In addition, Wolfgang Templ, from Nokia Bell Labs highlights "This work shows that the discussed 2D-3D dielectric integration of high-quality double layer encapsulated Graphene structures can open the way to the realisation of new high performing and micro-sized electro absorption modulators (EAMs) which can be combined with Si-based electronic into most advanced highly integrated photonic circuits".

Finally, Frank Koppens, ICREA Professor at ICFO and work-package leader of the Graphene Flagship, pinpoints "Data traffic is growing rapidly and will benefit society greatly, for example by enabling autonomous vehicles. The power consumption of high data traffic rates, however, is a key challenge that needs to be addressed. I'm happy to see that graphene-based modulators with much lower power consumption, as shown in this work, can tackle two societal challenges at the same time."

ADELPHI, Md. -- The Army of the future will involve humans and autonomous machines working together to accomplish the mission. According to Army researchers, this vision will only succeed if artificial intelligence is perceived to be ethical.

Researchers, based at the U.S. Army Combat Capabilities Development Command, now known as DEVCOM, Army Research Laboratory, Northeastern University and the University of Southern California, expanded existing research to cover moral dilemmas and decision making that has not been pursued elsewhere.

This research, featured in Frontiers in Robotics and AI, tackles the fundamental challenge of developing ethical artificial intelligence, which, according to the researchers, is still mostly understudied.

"Autonomous machines, such as automated vehicles and robots, are poised to become pervasive in the Army," said DEVCOM ARL researcher Dr. Celso de Melo, who is located at the laboratory's ARL West regional site in Playa Vista, California. "These machines will inevitably face moral dilemmas where they must make decisions that could very well injure humans."

For example, de Melo said, imagine that an automated vehicle is driving in a tunnel and suddenly five pedestrians cross the street; the vehicle must decide whether to continue moving forward injuring the pedestrians or swerve towards the wall risking the driver.

What should the automated vehicle do in this situation?

Prior work has framed these dilemmas in starkly simple terms, framing decisions as life and death, de Melo said, neglecting the influence of risk of injury to the involved parties on the outcome.

"By expanding the study of moral dilemmas to consider the risk profile of the situation, we significantly expanded the space of acceptable solutions for these dilemmas," de Melo said. "In so doing, we contributed to the development of autonomous technology that abides to acceptable moral norms and thus is more likely to be adopted in practice and accepted by the general public."

The researchers focused on this gap and presented experimental evidence that, in a moral dilemma with automated vehicles, the likelihood of making the utilitarian choice - which minimizes the overall injury risk to humans and, in this case, saves the pedestrians - was moderated by the perceived risk of injury to pedestrians and drivers.

In their study, participants were found more likely to make the utilitarian choice with decreasing risk to the driver and with increasing risk to the pedestrians. However, interestingly, most were willing to risk the driver (i.e., self-sacrifice), even if the risk to the pedestrians was lower than to the driver.

As a second contribution, the researchers also demonstrated that participants' moral decisions were influenced by what other decision makers do - for instance, participants were less likely to make the utilitarian choice, if others often chose the non-utilitarian choice.

"This research advances the state-of-the-art in the study of moral dilemmas involving autonomous machines by shedding light on the role of risk on moral choices," de Melo said. "Further, both of these mechanisms introduce opportunities to develop AI that will be perceived to make decisions that meet moral standards, as well as introduce an opportunity to use technology to shape human behavior and promote a more moral society."

For the Army, this research is particularly relevant to Army modernization, de Melo said.

"As these vehicles become increasingly autonomous and operate in complex and dynamic environments, they are bound to face situations where injury to humans is unavoidable," de Melo said. "This research informs how to navigate these moral dilemmas and make decisions that will be perceived as optimal given the circumstances; for example, minimizing overall risk to human life."

Moving in to the future, researchers will study this type of risk-benefit analysis in Army moral dilemmas and articulate the corresponding practical implications for the development of AI systems.

"When deployed at scale, the decisions made by AI systems can be very consequential, in particular for situations involving risk to human life," de Melo said. "It is critical that AI is able to make decisions that reflect society's ethical standards to facilitate adoption by the Army and acceptance by the general public. This research contributes to realizing this vision by clarifying some of the key factors shaping these standards. This research is personally important because AI is expected to have considerable impact to the Army of the future; however, what kind of impact will be defined by the values reflected in that AI."

The human condition is riddled with extreme events, which bring chaos into our lives. Natural disasters leave a trail of destruction, causing direct and horrible pain and suffering - costing lives, creating injuries, destroying houses, livelihoods, crops and broken infrastructures. While extensive research has been conducted on the economic and public healthcare costs of these types of disasters around the world, their effect does not end there. A team of researchers from the Hebrew University of Jerusalem sought to better understand the behavioral and social implications of these types of events around the world which resulted in a paper with the potential to change how policy makers and local governments respond in the wake of disasters.

With the research published in the journal Natural Hazards, Professor Claude Berrebi, Ariel Karlinsky and Dr. Hanan Yonah specifically wanted to understand how people reacted in the wake of disasters with regards to social behavior and whether it impacted their levels of philanthropy and criminal activity. While media has popularized a notion of widespread looting and chaos in the wake of major disasters, the researchers found that communities impacted by disasters actually experience a decrease in crime. Their article also found a marked increase in philanthropic activity amongst people that live nearby disaster areas but weren't directly affected by the disaster.

The team analyzed data of the disasters that took place in the US between 2004 and 2015, a period which saw over 10,000 individual disasters of differing scope and killed over 8,300 people, causing damage in excess of 100 billion dollars. The researchers carefully compared data between communities that were directly affected versus those who had been spared direct impact from disasters.

The study revealed that disasters generally don't contribute to marked increase in criminal activity and in fact there were definite reductions in crime levels - although surrounding unaffected areas often reported an uptick in crime.

While directly affected areas understandably saw a decrease in charitable giving, neighboring regions and even those communities more distanced from the disaster zone would see marked increase in philanthropy.

The paper proposed that the philanthropic trends they found are generally related to a model known as COR (Conservation of Resources.) The model suggests that when a person feels fearful for his or her own resources, they are likely to be overly protective and reduce spending on anything that is not essential so as to best preserve for their own wellbeing and survival. At the same time, increased giving in neighboring areas is driven by a sense of empathy and solidarity with people who live near them and were so impacted by the disaster.

Professor Berrebi added, "These findings have important implications for policy makers and others who are in charge of disaster response and crisis management. The study demonstrates how people respond when their resources are threatened, or even are believed to be threatened and this leads people to withdraw from social involvement while at the same can inspire others to come out in solidarity and financial support. This is particularly important as we recognize that often official channels and governments can be slower in their responses and therefore policies that encourage volunteerism and increased civilian support for those directly affected can be of vital assistance in the immediate wake of such events."

We live in modern times, that is full of electronics. Smartphones, laptops, tablets, and many other devices need electrical energy to operate. Portable devices made our lives easier, so novel solutions in clean energy and its storage are desirable. Lithium-ion (Li-ion) batteries are the most common solutions that dominate the global market and are a huge problem due to their insufficient recovery. Because of their limited power, short cycle life, and non-environment-friendly nature, scientists recently focused on novel solutions like supercapacitors that offer much more than batteries. Why? Let's take a look closer at these devices.

Supercapacitors bring together the properties of a standard capacitor and the Li-ion battery. In practice, these devices store more energy than capacitors and deliver energy faster than batteries. Their secret lies inside, hiding two essential components. The first one is two highly porous electrodes made of the material that conducts electricity; these electrodes are separated by a membrane to prevent a shortcut. The second one is an electrolyte that plays a crucial role in supercapacitors. The electrolyte has a lot of ions that are close to each other and fill the pores. There are two types of ions - positively charged called cations and negatively charged called anions. When the device is turned on (the potential difference is applied between these two electrodes), ions start to travel in and out of the pores (cations and anions move in opposite directions), and the electric current flows. One of the most commonly used materials that maintain porosity is activated charcoal. If pores are large, the device charges fast but stores low energy. If the pores are narrow, the device provides more energy but charges more slowly. Does it mean smaller is better? Yes, however, the ions' velocity thought their travel in the pores needed to be accelerated.

Recently, an international group led by Svyatoslav Kondrat from the Institute of Physical Chemistry, Polish Academy of Sciences (IPC PAS) presented research work describing how to speed up ion transport in narrow pores. Why? To charge the supercapacitor faster. First of all, researchers focused on the theory. They presented slit-like pores with a size of about 0.6 nm, that is, 0.6 meters divided into billion pieces, just slightly larger than the ion itself, while its length was below 20 nm. What a small size! It is even smaller than viruses. When the electrodes are polarized (the external potential is applied to electrodes to push ions in particular directions), the ions outside of the pores rush to the pores. Imagine that they move like cars on a highway, entering a very narrow tunnel. However, instead of two, three, or four lanes going opposite directions, all lanes are merged. When cars go fast, the highway is very crowded, and they may quickly block the tunnel and get stuck in traffic. The same happens to ions. When the potential difference applied to an electrode is varied too fast, ions entering the electrode's pores block the ions who try to leave the pores. In this way, the pores are clogged. What does it mean in practice?

The bad news, it means slower charging (lower power density) of the supercapacitor. The researchers proposed the solution: Let's not push ions too fast but, well, also not too slow; let's adjust the velocity by a tiny step rate. Based on their idea, they performed multiple complex computer simulations that gave promising results. That was a theory. What about practice? Svyatoslav Kondrat says, "We had the simulation results, and we were curious how it works in practice." Experiments performed in Volker Presser (INM, Saarbrücken) used highly porous electrodes filled with ions. Researchers have shown that ions can travel quicker without pore-clogging when treated with tiny electrical impulses instead of abrupt charging or discharging. This way, they found how to accelerate the charging and discharging processes even if the electrode's pores are as narrow as just 0.6 nm. The research was done under an international collaboration and reported on November 30 in the journal Nature Communications.

Svyatoslav Kondrat says, "The results are encouraging. It is exciting that also discharging can be accelerated. It is like making your cars leave the tunnel faster, even though you have control only over the cars outside of the tunnel. This is relevant for some processes like capacitive water desalination, where operation speed is very important".

Their findings open up new opportunities to tremendously accelerate charging and discharging even in subnanometer pores. This approach to the novel solution application can provide a new path for more widespread use of these environmentally-friendly electrochemical devices.

In shallow water, less than 30 metres, the survival of hard corals depends on photosynthetic unicellular algae (zooxanthellae) living in their tissues. But how does the coral adapt at depth when the light disappears? French researchers from the CNRS, EPHE-PSL and their international collaborators, associated with Under the Pole (Expedition III), have studied for the first time the distribution of these so-called mesophotic corals in the French Polynesian archipelago, from the surface to 120 metres deep (with a record descent of 172 metres). As the amount of light decreases, the coral associates with other filamentous algae, in addition to zooxanthellae, which become inserted into its skeleton. These algae, the only ones found at this depth, could therefore play an important role in the coral's adaptation to life at depth as they can capture shorter light wavelengths. This work provides new knowledge on deep-sea coral ecosystems, which are the focus of growing interest due to their potential role as a refuge from the more directly threatened surface reefs. This research was supported by the ANR and the results are published in The ISME Journal.

Canadian researchers are the first to study how different patterns in the way older adults walk could more accurately diagnose different types of dementia and identify Alzheimer's disease.

A new study by a Canadian research team, led by London researchers from Lawson Health Research Institute and Western University, evaluated the walking patterns and brain function of 500 participants currently enrolled in clinical trials. Their findings are published today in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

"We have longstanding evidence showing that cognitive problems, such as poor memory and executive dysfunction, can be predictors of dementia. Now, we're seeing that motor performance, specifically the way you walk, can help diagnose different types of neurodegenerative conditions," says Dr. Manuel Montero-Odasso, Scientist at Lawson and Professor at Western's Schulich School of Medicine & Dentistry.

Dr. Montero-Odasso is world renowned for his research on the relationship between mobility and cognitive decline in aging. Leading the Mobility, Exercise and Cognition (MEC) team in London, he is pioneering novel diagnostic approaches and treatments to prevent and combat early dementia.

This study compared gait impairments across the cognitive spectrum, including people with Subjective Cognitive Impairment, Parkinson's Disease, Mild Cognitive Impairment, Alzheimer's disease, Lewy body dementia and Frontotemporal dementia, as well as cognitively healthy controls.

Four independent gait patterns were identified: rhythm, pace, variability and postural control. Only high gait variability was associated with lower cognitive performance and it identified Alzheimer's disease with 70 per cent accuracy. Gait variability means the stride-to-stride fluctuations in distance and timing that happen when we walk.

"This is the first strong evidence showing that gait variability is an important marker for processes happening in areas of the brain that are linked to both cognitive impairment and motor control," notes Dr. Frederico Perruccini-Faria, Research Assistant at Lawson and Postdoctoral Associate at Western's Schulich School of Medicine & Dentistry, who is first author on the paper. "We've shown that high gait variability as a marker of this cognitive-cortical dysfunction can reliably identify Alzheimer's disease compared to other neurodegenerative disorders."

When cognitive-cortical dysfunction is happening, the person's ability to perform multiple tasks at the same time is impacted, such as talking while walking or chopping vegetables while chatting with family.

Having gait variability as a motor marker for cognitive decline and different types of conditions could allow for gait assessment to be used as a clinical test, for example having patients use wearable technology. "We see gait variability being similar to an arrhythmia. Health care providers could measure it with patients in the clinic, similar to how we assess heart rhythm with electrocardiograms," adds Dr. Montero-Odasso.

In today's digital age, the use of "Internet-of-things" (devices embedded with softwares and sensors) has become widespread. These devices include wireless equipment, autonomous machinery, wearable sensors, and security systems. With their intricate structures and properties stems the need to scrutinize them closely to assess their safety and utility and rule out any potential defects. But, at the same time, damage to the device during inspection must be avoided.

Terahertz (THz) imaging, based on radiation with frequencies between 0.1 and 10 THz, is one such non-destructive method that is rapidly gaining popularity owing to its high penetration, resolution, and sensitivity. Conventional THz cameras, however, are bulky and rigid, thereby limiting their potential in imaging uneven surfaces. Moreover, their high cost and lack of versatility in sensor configurations make them a rather impractical alternative, calling for more adaptable sensors.

To this end, a team of researchers from the Tokyo Tech, led by Associate Professor Yukio Kawano, have now addressed this gap by designing a flexible and free standing THz sensor array that can be used to image blind ends of irregularly shaped objects.

Ecstatic about their findings published in Advanced Functional Materials, Dr. Kawano states, "Given the diversity in shapes, structures, and sizes of test objects, the camera design and sensor must be adapted to conform to different configurations. In our study, we have developed a simple and cost-effective fabrication method for generating THz cameras with adaptable shapes."

The scientists knew that the material used in such sensors must have good absorption in the THz spectrum along with a high efficiency of converting emissions into detectable electric signals. For this reason, they selected carbon nanotube (CNT) films, which also possess good mechanical strength and flexibility. They passed the CNT solution through a polyimide film with laser induced slits and a membrane filter using a vacuum. Upon drying, the CNT solution remained as a free standing suspended structure between the layers of the patterned polyimide film. Further, they developed a simple fabrication process based on the self-assembly of CNT film array and its ability to from electrodes at both ends. For this, they evaporated metal electrodes over the patterned polyimide film. Together, these processes generated a THz camera patch sheet with multiple cameras. Interestingly, the structure of the suspended CNT film could be modified by altering the filtering conditions and thus the frictional force, making the process customizable.

Moreover, the patch sheet could be cut with scissors into smaller portable and wearable sensors that can be attached to the surface of the test object for better coverage. The researchers were able to demonstrate its industrial applications by detecting and visualizing cracks, impurities and uneven coating of polymers in a resin and by detecting sludge within a bent pipe, thus underscoring the potential of the camera in quality control operations.

Highlighting the applications of their design, Dr. Kawano remarks, "Our patch camera can be easily set up for imaging of large and unmovable objects. The unique 2D THz camera patch can ease restrictions pertaining to the shapes and locations of objects, contributing significantly to non-destructive monitoring sensor networks."

Images provide information - what we can observe with our own eyes enables us to understand. Constantly expanding the field of perception into dimensions that are initially hidden from the naked eye, drives science forward. Today, increasingly powerful microscopes let us see into the cells and tissues of living organisms, into the world of microorganisms as well as into inanimate nature. But even the best microscopes have their limits. "To be able to observe structures and processes down to the nanoscale level and below, we need new methods and technologies," says Dr Silvio Fuchs from the Institute of Optics and Quantum Electronics at the University of Jena. This applies in particular to technological areas such as materials research or data processing. "These days, electronic components, computer chips or circuits are becoming increasingly small," adds Fuchs. Together with colleagues, he has now developed a method that makes it possible to display and study such tiny, complex structures and even "see inside" them without destroying them. In the current issue of the scientific journal "Optica", the researchers present their method - Coherence Tomography with Extreme Ultraviolet Light (XCT for short) - and show its potential in research and application.

Light penetrates the sample and is reflected by internal structures

The imaging procedure is based on optical coherence tomography (OCT), which has been established in ophthalmology for a number of years, explains doctoral candidate Felix Wiesner, the lead author of the study. "These devices have been developed to examine the retina of the eye non-invasively, layer by layer, to create 3-dimensional images." At the ophthalmologist, OCT uses infrared light to illuminate the retina. The radiation is selected in such a way that the tissue to be examined does not absorb it too strongly and it can be reflected by the inner structures. However, the physicists in Jena use extremely short-wave UV light instead of long-wave infrared light for their OCT. "This is due to the size of the structures we want to image," says Felix Wiesner. In order to look into semiconductor materials with structure sizes of only a few nanometres, light with a wavelength of only a few nanometres is needed.

Nonlinear optical effect generates coherent extremely short-wave UV light

Generating such extremely short-wave UV light (XUV) used to be a challenge and was almost only possible in large-scale research facilities. Jena physicists, however, generate broadband XUV in an ordinary laboratory and use what are called high harmonics for this purpose. This is radiation that is produced by the interaction of laser light with a medium and it has a frequency many times that of the original light. The higher the harmonic order, the shorter the resulting wavelength. "In this way, we generate light with a wavelength of between 10 and 80 nanometres using infrared lasers," explains Prof. Gerhard Paulus, Professor of Nonlinear Optics at the University of Jena. "Like the irradiated laser light, the resulting broadband XUV light is also coherent, which means that it has laser-like properties."

In the work described in their current paper, the physicists exposed nanoscopic layer structures in silicon to the coherent XUV radiation and analysed the reflected light. The silicon samples contained thin layers of other metals, such as titanium or silver, at different depths. Because these materials have different reflective properties from the silicon, they can be detected in the reflected radiation. The method is so precise that not only can the deep structure of the tiny samples be displayed with nanometre accuracy, but - due to the differing reflective behaviour - the chemical composition of the samples can also be determined precisely and, above all, in a non-destructive manner. "This makes coherence tomography an interesting application for inspecting semiconductors, solar cells or multilayer optical components," says Paulus. It could be used for quality control in the manufacturing process of such nanomaterials, to detect internal defects or chemical impurities.

Globalization, digitalization, sustainabilization - three major waves of transformation are unfolding around the world. The social upheaval caused by these transformation processes has given rise to populist movements that endanger social harmony and threaten democratic values. What rules and institutions can promote stability in the face of such systemic risks? A new study published by the Institute for Advanced Sustainability Studies (IASS) offers some surprising answers.

The coronavirus pandemic has demonstrated for the first time how a systemic risk can sweep across our globalized world. It began with the little-noticed outbreak of an unknown illness in Wuhan. Then, like an avalanche, the virus spread swiftly throughout China, then to neighbouring countries, and across the globe. As its effects rippled through healthcare systems, disrupted global supply chains, industries, logistics and transportation networks, an initially local event stretched social systems worldwide to their limits.

This scenario is typical of systemic risks, which are complex, interconnected, and highly stochastic, and to a significant degree non-linear risks with tipping points that can threaten the social fabric of complex societies.

How do people respond to these risks? Large segments of the population continue to place their trust in the institutions of society and abide by the guidance and regulations issued by governments to tackle the pandemic. However, there are sections of society that mistrust these institutions and are sceptical of official pronouncements on the pandemic. Fuelled by social media and suspecting that "shadowy powers" are steering events, they turn to populist movements. This example shows how public opinion can diverge suddenly and with little warning, splitting society into two. Such rapid shifts, spurred by a systemic risk such as the current pandemic, can pose a threat to the diversity and cohesion of open societies.

Complexity science and the great transformations

In their study 'Systemic Risk: The Threat to Societal Diversity and Coherence', the two authors, thermodynamic scientist Klaus Lucas and sociologist Ortwin Renn, combine the insights of complexity science with conceptual considerations around the management of systemic risks. The study considers the impacts of three major waves of transformation currently unfolding (globalization, digitalization and the sustainabilization), which are leading to changes and dislocations similar to those triggered by the coronavirus pandemic.

An example: The nationalist response to globalization

In the case of globalization, strong counter-movements have arisen that advocate a revival of nationalist and often ethnically-defined policies. These movements seek to exclude or marginalize purportedly 'foreign' elements and promote the introduction of protectionist trade policies. The emergence of these movements follows an erosion of trust in the institutions of society - first and foremost in the democratic pillars of parliament, political parties, and the justice system. More and more often, populist movements are gaining ground, resulting in the increasing polarization of populations.

Digitalization is a similarly disruptive phenomenon: while some sections of society benefit from considerable gains in comfort and efficiency, elsewhere it impinges on personal freedoms and identities, and limits autonomy. In addition, digitalization leads to a concentration of economic and creative power in the hands of a small number of large actors, enabling them to pursue their interests with little democratic oversight. And while digitalized processes provide opportunities to strengthen democratic structures by increasing transparency or facilitating political participation, the advent of digital echo chambers and bots heightens polarization and hinders the social discourse that is indispensable to democratic decision-making.

The third global transformation is the broad process of "sustainabilization", which seeks to bring sustainable principles and developments into the realms of politics, economy, and societal behaviour. This transformation is also attended by ruptures, contradictions, and a variety of related risks. Conflicts frequently arise between processes of sustainabilization and the other major transformations.

According to Renn and Lucas, these unfolding transformations set in motion processes that require societies to adapt to their altered living conditions and should therefore be viewed as systemic risks. The recent success of political parties that did not even exist five years previously and the demise of established parties in European countries such as Greece, France and Italy, are examples of such sudden shifts.

Grappling with the dilemma

The authors argue that many features that characterize and influence complex structures in nearly every domain of nature, technology, and society can be derived from fundamental patterns revealed in dynamic models in physics and chemistry. Applying these findings from complexity science to the structure of social risks offers new insights. In particular, it renders visible the role of self-organization alongside the familiar social steering mechanisms of hierarchy, competition and cooperation. "Its effect is underestimated in almost all social science theories," says Professor Ortwin Renn, Scientific Director at the IASS.

Considering contemporary issues around migration and integration, this insight suggests that social cohesion is not a product of rules, competition or shared values alone; rather, under certain circumstances, new elements can contribute to the basic functionality of the system through self-organization - for example through socio-economic development or cultural achievements. However, this is only possible where new entrants are offered the opportunities for cooperation that they need to develop and realize their potential. Complexity science shows that creative solutions and unusual adaptation processes often emerge around elements that enter existing structures and, through their own creative processes of adaptation, bring innovations into the system.

At the same time, the rules of competition and hierarchy ideally act as guard rails along an otherwise broad development corridor, correcting cooperative arrangements that emerge through self-organization where these do not contribute to the stability of the system or prove counter-productive. This implies that, in the absence of hierarchy and competition, cooperation could well prevent or endanger cohesion. From the perspective of complexity science, it is indispensable for the stability of a system that important rules for interactions are predetermined in order to limit the creative opportunities for self?organization without prescribing certain actions or establishing prerequisites that would unduly restrict the development corridor.

This requires that systems be constituted in such a way that relationships between agents develop in the process of self?organization so that they, at least in the statistical average, bring about and maintain successful processes of adaptation to changing conditions.

Fundamental values as the basis for societal coherence

The authors recommend the basic values enshrined in the constitutions of countries and the fundamental freedoms noted in the Charter of the United Nations. These values constitute the basic principles of human existence and cooperation. In addition, it is vital that decision-making and regulatory institutions be suitably equipped to enforce their authority. For cooperative models to emerge and flourish, actors must be able to trust in the ability of the governance system to both ensure that all actors play by the rules and to penalize violations where necessary.

In view of the crises facing modern democracies such as migration and populism, societies are well advised to place more trust in the effectiveness of dynamic evolving structures that are open and rooted in self-organization and spontaneous cooperation. Creating favourable conditions for self-organization, is an essential prerequisite for the further humane development of systems and the achievement of greater sustainability in the long term. This suggests that creative and innovative solutions for the conflicts and disruptions that inevitably arise both within and between global transformations are more likely to emerge in such contexts than where cooperation is limited to closed communities of values or in settings defined by the principles of hierarchy and competition. In order to be effective, self?organization must emerge within guard rails that are grounded in fundamental values (human rights) and embedded within an enabling environment that fosters competition and innovation.

The lithium-ion battery powers everything from mobile phones to laptops to electric vehicles. Scientists worldwide are always on the hunt for new and improved components to build better batteries for these and other applications.

Scientists from the U.S. Department of Energy’s (DOE) Argonne National Laboratory report a new electrode design for the lithium-ion battery using the low-cost materials lead as well as carbon. Contributors to this pivotal discovery also include scientists from Northwestern University, Brookhaven National Laboratory and the Ulsan National Institute of Science and Technology (UNIST).

“Our new anode could offer a new revenue stream for the large industry currently engaged in lead-acid battery manufacturing and recycling.” — Eungje Lee, principal author and materials scientist in Argonne’s Chemical Sciences and Engineering division

“Our research has exciting implications for designing low-cost, high-performance, sustainable lithium-ion batteries that can power hybrid and all-electric vehicles,” said Eungje Lee, principal author and materials scientist in Argonne’s Chemical Sciences and Engineering (CSE) division.

Lithium-ion batteries work by insertion of lithium ions into the anode during charge and their removal during discharge. The present-day graphite anodes can operate for thousands of such charge-discharge cycles but appear to have reached their limit in terms of energy storage capacity.

“We decided to investigate lead as an intriguing alternative to graphite for the anode material,” said Lee. Lead is especially attractive because it is abundant and inexpensive. In addition, it has a well-established supply chain owing to the long history of lead-acid batteries providing ancillary power for automobiles and is one of the most recycled materials in the world. The current lead recycling rate is 99% in the United States.

“Our new anode could offer a new revenue stream for the large industry currently engaged in lead-acid battery manufacturing and recycling,” Lee added.

The team’s anode is not a plain slab of lead but innumerable microscopic particles with an intricate structure: lead nanoparticles embedded in a carbon matrix and enclosed by a thin lead oxide shell. While this structure sounds complex, the team invented a simple, low-cost method for fabricating it.

“Our method involves shaking, for several hours, large lead oxide particles mixed with carbon powder until they form microscopic particles with the desired core-shell structure,” explained Christopher Johnson, the principal investigator of the project and an Argonne Distinguished Fellow in the CSE division.

Tests in laboratory cells over 100 charge-discharge cycles showed that the new lead-based nanocomposite anode attained twice the energy storage capacity of current graphite anodes (normalized for the same weight). Stable performance during cycling was possible because the small particle size alleviated stresses while the carbon matrix provided needed electrical conductivity and acted as a buffer against damaging volume expansion during cycling. The team also found that adding a small amount of fluoroethylene carbonate to the standard electrolyte significantly improved performance.

The researchers investigated the charge-discharge mechanism of their anode at the GeoSoilEnviro Center for Advanced Radiation Sources (GSECARS), operated by the University of Chicago, at Argonne’s Advanced Photon Source, a DOE Office of Science User Facility. By means of synchrotron X-ray diffraction, they were able to track the changes in phases of the anode material while it was being charged and discharged. These characterization results combined with those collected at the Northwestern University Atomic and Nanoscale Characterization Center and the National Synchrotron Light Source II, a DOE User Facility at Brookhaven, revealed a previously unknown electrochemical reaction between lead and lithium ions that occurs upon charge and discharge.

“This fundamental insight may prove important in understanding the reaction mechanism of not only lead but also silicon anodes,” said Lee. The silicon anode is another low-cost, high-performance candidate for next-generation lithium-ion batteries.

“Our discovery challenges the current understanding of this type of electrode material,” noted Johnson. “Our findings also provide exciting implications for designing low-cost, high-performance anode materials for transportation and stationary energy storage, such as backup power for the electric grid.”

The team’s paper appeared in a recent special issue of Advanced Functional Materials honoring the 98th birthday of John B. Goodenough, co-winner of the 2019 Nobel Prize in Chemistry for development of the lithium-ion battery. In addition to Johnson and Lee, Argonne authors include Jinhyup Han, Seoung-Bum Son, Jihyeon Gim and Chi Cheung Su. Other authors are Jehee Park (UNIST), Seong-Min Bak (Brookhaven), Cesar Villa (Northwestern), Xiaobing Hu (Northwestern), Vinayak P. Dravid (Northwestern) and Youngsik Kim (UNIST).