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Anaphylactic shock, an exacerbated allergic reaction that can prove fatal, is sometimes caused by the use of drugs during surgery. In most of these extreme reactions, evidence can be provided that patients have anti-drug antibodies of the IgE class. In 10 to 20% of anaphylactic cases evidence for the involvement of anti-drug IgE is lacking. Anti-drug IgE enable activation of mast cells and basophils that release histamine, a potent mediator involved in anaphylaxis. Teams from the Institut Pasteur, Inserm, the Paris Public Hospital Network (AP-HP), the CNRS, Paris-Sud University and Sorbonne University have successfully identified a new pathological mechanism responsible for these previously unexplained cases, involving neutrophils activated by antibodies of the IgG class. These findings, published on July 10 in the journal Science Translational Medicine, will help improve diagnosis and treatment for patients with this type of shock.

Anaphylaxis is a hyperacute allergic reaction caused by an inappropriate immune response following the introduction of a usually harmless antigen into the body. When this antigen binds to antibodies already in the body, it triggers the secretion of large quantities of potent vasodilating mediators, sending the patient into a state of shock that may result in multiple organ failure and even death.

Anaphylaxis may be brought about by various substances, including drugs (antibiotics or neuromuscular blocking agents), food and insect venom. In this study, the scientists focused on allergic reactions to neuromuscular blocking agents (NMBAs), drugs used during general anesthesia to induce muscle relaxation. The incidence of anaphylactic shock caused by NMBAs is one case in every 10,000 to 20,000 surgeries, representing approximately 3 to 5 cases each week in the Greater Paris area.

Although it was already known that IgE antibodies could cause anaphylaxis, teams from the Institut Pasteur, Inserm, the Paris Public Hospital Network (AP-HP), the CNRS, Paris-Sud University and Sorbonne University have demonstrated in a clinical study that IgG antibodies can also be involved in drug-induced anaphylactic shocks. This unexpected role of IgG antibodies had already been identified in mice in 2011 by some of the same authors.[1]

This multicenter study known as "NASA", led by Bichat Hospital (part of the Paris Public Hospital Network), was launched in 2012 by a consortium of scientists, clinical biologists and anesthetists. The consortium monitored 86 patients with perioperative anaphylactic shock and 86 control patients in 11 hospitals in the Greater Paris area, coordinated at Bichat Hospital by immunologist Professor Sylvie Chollet-Martin (Paris-Sud University) and anesthetist Professor Dan Longrois. Blood samples were taken as soon as an anaphylactic shock occurred in the operating room, enabling the scientists to identify the alternative IgG-dependent mechanism. They demonstrated that IgG antibodies activate neutrophils (50-70% of our white blood cells), releasing high doses of harmful vasodilating mediators. Neutrophil activation was more pronounced in cases of severe shock than in cases of moderate shock. Interestingly, the IgG-neutrophil pathway was also identified in most cases of shock where the traditional IgE-dependent mechanism was observed, suggesting that IgGs and neutrophils may contribute to the severity of most cases of shock via an additive effect.

"These findings elucidate 10 to 20% of cases of anaphylactic shock that previously had no biological explanation. They will be extremely valuable in refining diagnosis in these patients and avoiding any future exposure with the drug that triggered the allergic reaction," explains Professor Sylvie Chollet-Martin (Paris-Sud University), joint last author of the study and Head of the Immunology laboratory on Autoimmunity and Hypersensitivity at Bichat Hospital.

"Although IgG antibodies are known to protect the body from infection and to act as aggressors in some autoimmune diseases, this study reveals that they may be involved in humans in another reaction that is harmful for the body, anaphylaxis. We are currently carrying out experimental research to explore how we might block this new activation pathway for IgG antibodies so that we can propose a therapeutic solution," comments Pierre Bruhns, joint last author of the study, Inserm Research Director and Head of the Institut Pasteur's Antibodies in Therapy and Pathology Unit.

Anaphylactic shock, an exacerbated allergic reaction that can prove fatal, is sometimes caused by the use of drugs during surgery. In most of these extreme reactions, evidence can be provided that patients have anti-drug antibodies of the IgE class. In 10 to 20% of anaphylactic cases evidence for the involvement of anti-drug IgE is lacking. Anti-drug IgE enable activation of mast cells and basophils that release histamine, a potent mediator involved in anaphylaxis. Teams from the Institut Pasteur, Inserm, the Paris Public Hospital Network (AP-HP), the CNRS, Paris-Sud University and Sorbonne University have successfully identified a new pathological mechanism responsible for these previously unexplained cases, involving neutrophils activated by antibodies of the IgG class. These findings, published on July 10 in the journal Science Translational Medicine, will help improve diagnosis and treatment for patients with this type of shock.

Anaphylaxis is a hyperacute allergic reaction caused by an inappropriate immune response following the introduction of a usually harmless antigen into the body. When this antigen binds to antibodies already in the body, it triggers the secretion of large quantities of potent vasodilating mediators, sending the patient into a state of shock that may result in multiple organ failure and even death.

Anaphylaxis may be brought about by various substances, including drugs (antibiotics or neuromuscular blocking agents), food and insect venom. In this study, the scientists focused on allergic reactions to neuromuscular blocking agents (NMBAs), drugs used during general anesthesia to induce muscle relaxation. The incidence of anaphylactic shock caused by NMBAs is one case in every 10,000 to 20,000 surgeries, representing approximately 3 to 5 cases each week in the Greater Paris area.

Although it was already known that IgE antibodies could cause anaphylaxis, teams from the Institut Pasteur, Inserm, the Paris Public Hospital Network (AP-HP), the CNRS, Paris-Sud University and Sorbonne University have demonstrated in a clinical study that IgG antibodies can also be involved in drug-induced anaphylactic shocks. This unexpected role of IgG antibodies had already been identified in mice in 2011 by some of the same authors.1

This multicenter study known as "NASA", led by Bichat Hospital (part of the Paris Public Hospital Network), was launched in 2012 by a consortium of scientists, clinical biologists and anesthetists. The consortium monitored 86 patients with perioperative anaphylactic shock and 86 control patients in 11 hospitals in the Greater Paris area, coordinated at Bichat Hospital by immunologist Professor Sylvie Chollet-Martin (Paris-Sud University) and anesthetist Professor Dan Longrois. Blood samples were taken as soon as an anaphylactic shock occurred in the operating room, enabling the scientists to identify the alternative IgG-dependent mechanism. They demonstrated that IgG antibodies activate neutrophils (50-70% of our white blood cells), releasing high doses of harmful vasodilating mediators. Neutrophil activation was more pronounced in cases of severe shock than in cases of moderate shock. Interestingly, the IgG-neutrophil pathway was also identified in most cases of shock where the traditional IgE-dependent mechanism was observed, suggesting that IgGs and neutrophils may contribute to the severity of most cases of shock via an additive effect.

"These findings elucidate 10 to 20% of cases of anaphylactic shock that previously had no biological explanation. They will be extremely valuable in refining diagnosis in these patients and avoiding any future exposure with the drug that triggered the allergic reaction," explains Professor Sylvie Chollet-Martin (Paris-Sud University), joint last author of the study and Head of the Immunology laboratory on Autoimmunity and Hypersensitivity at Bichat Hospital.

"Although IgG antibodies are known to protect the body from infection and to act as aggressors in some autoimmune diseases, this study reveals that they may be involved in humans in another reaction that is harmful for the body, anaphylaxis. We are currently carrying out experimental research to explore how we might block this new activation pathway for IgG antibodies so that we can propose a therapeutic solution," comments Pierre Bruhns, joint last author of the study, Inserm Research Director and Head of the Institut Pasteur's Antibodies in Therapy and Pathology Unit.

Making minor changes to how food is produced, supplied and consumed around the world could free up around a fifth of agricultural land, research suggests.

Scientists have applied the British cycling team's strategy of marginal gains - the idea that making multiple small changes can lead to significant effects overall - to the global food system.

They found that small steps - such as reducing food waste, tweaking diets and improving the efficiency of food production - could together reduce the amount of land required to feed the planet by at least 21 per cent.

Altering diets in developed nations was also found to have the greatest potential to reduce the impact of food production.

Changes are needed to continue to provide nutritional food without damaging the environment, experts say. Freeing up areas currently used to grow crops and keep livestock could also aid conservation efforts and improve biodiversity

The report - by scientists from the University of Edinburgh and the Karlsruhe Institute of Technology - suggests small changes such as eating slightly less meat, substituting chicken or pork for beef and lamb, and reducing transport and processing losses.

Other proposals include increasing agricultural yields, as well as less conventional shifts such as greater consumption of insects, plant-based imitation meat and lab-grown meat.

The team calculated the combined effects of their proposed changes using the latest data from the Food and Agriculture Organization of the United Nations.

Previous research has focused on a few large changes that are difficult to achieve, researchers say. They argue that the marginal gains approach, which has made British cycling among the best in the world, is more likely to be attainable.

Dr Peter Alexander, of the University of Edinburgh's School of GeoSciences, who led the study, said: "The current system is failing to deliver the food we need to be healthy and is doing so in a way that is causing a crisis for biodiversity and contributing to climate change.

"While a transformational change is required, we need an approach that is achievable in practice. A vegan or vegetarian diet isn't likely to be adopted by everyone and we think a set of small steps in the right directions will be more likely to be adopted and ultimately successful, and will go a substantial way to reducing the negative outcomes."

Professor Mark Rounsevell, of the Karlsruhe Institute of Technology and the University of Edinburgh, said: "Recent reports have suggested a single global diet as healthy and environmentally sustainable, ignoring important differences between countries and regions, including, for example, the need to increase protein consumption in some developing countries.

"Our results show that in places like Europe and the US, consumers can play the biggest role in reducing environmental harm through dietary change, while in less developed countries increasing production efficiency is more important."

The queen problem is a mathematical task, which already had the great mathematician Carl Friedrich Gauss occupied, but for which he surprisingly did not find the right solution. The challenge here is how to arrange eight queens on a classical chess board with 8 x 8 squares so that no two queens threaten each other. Mathematically, it is relatively easy to determine that there are 92 different ways to arrange the queens. On a chess board with 25 x 25 squares there are already more than 2 billion possibilities. The calculation of this number alone took a total of 53 years of CPU time.

The task becomes even more difficult if some queens are already on the field and certain diagonals may not be occupied. Recently it has been shown that with these additional restrictions the problem with 21 queens can no longer be solved by classical mathematical algorithms in a reasonable time. "I came across this topic by chance and thought that quantum physics really could play out its advantages here," says Wolfgang Lechner from the Department of Theoretical Physics at the University of Innsbruck and the Institute of Quantum Optics and Quantum Information at the Austrian Academy of Sciences. Together with Helmut Ritsch and the PhD students Valentin Torggler and Philipp Aumann, Lechner developed a quantum chessboard on which the queens puzzle could be solved experimentally with the help of quantum physics.

From atoms to chess queens

"An optical lattice of laser beams into which individual atoms are placed can be used as a chessboard," explains Helmut Ritsch, who is also a member of the Department of Theoretical Physics in Innsbruck. "By adjusting the interaction between the atoms, we can make chess queens out of the atoms, who behave according to the chess rules, i.e. avoid each other in all directions of the game board". This repulsion of the particles is generated with the help of lasers, which are applied along the directions of motion. Via an optical resonator - two mirrors above and below the optical lattice - this interaction is further intensified and becomes thus effective over much greater distances.

"One could also play this game with correspondingly repulsive billiard balls," says Ritsch. "But because there are so many possibilities, it would take a very, very long time. It is therefore crucial that the atoms are cooled down very strongly and that their quantum properties take effect. Because they then behave like waves and can test many possibilities at the same time. Then it quickly becomes apparent whether there is a valid solution according to chess rules for the given conditions.

Quantum supremacy on the horizon

The answer to the question whether there is a solution under the given restrictions can be read very easily from the light emitted by the resonator. But the specific arrangement of the atomic queens could only be determined by atomic microscopy, a method recently successfully applied by related experiments.

Simulations on classical computers strongly suggest that the experiment designed by the Innsbruck theorists would lead to a result much faster than any mathematical algorithm on a classical computer could. "This would allow for the first time to clearly prove the supremacy of quantum computers for the calculation of certain optimization problems," summarizes Wolfgang Lechner. "The control of a few dozen atoms is already standard practice in the laboratory, which is why the implementation of this idea might soon become reality."

A new model based on daily oceanographic data and the movements of tagged whales has opened the potential for stakeholders to see where in the ocean endangered blue whales are most likely to be so that ships can avoid hitting them.

The research was published in Diversity and Distributions by Dr. Briana Abrahms, research ecologist at NOAA Fisheries' Southwest Fisheries Science Center, and related the movements of more than 100 tagged blue whales to daily oceanographic conditions. Abrahms found that ocean conditions affected the whales' travels in very predictable ways.

Abrahms and her colleagues are now developing an app that will allow managers and ship crews to predict the location of blue whales as they transit along the West Coast. The app will also be accessible to the public and to managers making recommendation on vessel slow-downs or the use of alternative shipping lanes.

"The more we learn about how the physical ocean affects whales and other marine life, the better we are able to predict where those species will be," Abrahms said. "The goal is to put this technology into the hands of managers, the shipping industry and other users who can most use it to help protect these animals from ship strikes and other human threats."

Blue whales are the largest animal to have ever existed. They can grow to the length of a basketball court, though their diet is primarily krill - tiny shrimp-like creatures less than two inches long. An endangered species, roughly 1500 blue whales are estimated to spend time in the waters off the U.S. West Coast. Movement data on the whales shows that they frequent areas off Santa Barbara and San Francisco, California, putting them at increased risk of ship strike near some of the West Coast's busiest ports.

Satellite tags temporarily attached to more than 100 blue whales from 1994 to 2008 helped show that the whales respond to specific ocean conditions that create good habitat for the whales and their prey. These environmental factors include sea surface temperature, ocean productivity, and seafloor topography. New 3-D oceanographic modeling has also allowed scientists to begin estimating water properties at various depths, which Abrahms and her colleagues found are also good predictors of whale presence.

Such ocean monitoring data are available from an ocean model that integrates data from ocean buoys, satellites, and shipboard surveys, and feeds into ecological models that can be used to estimate the location of whales.

The research supports increasing use of dynamic ocean information to inform decisions about human activities, from ship traffic to fishing. These activities can be adjusted in concert with near-real time ocean conditions that affect the distribution of marine life, such as fish and marine mammals. Dynamic ocean management can help fisheries better avoid entanglement of whales or the incidental bycatch of other protected species. It can also help ships avoid striking whales, which remains a serious mortality risk for blue whales off the West Coast.

"We're harnessing the best and most current environmental data based on what the whales have indicated they pay most attention to," Abrahms said. "That tells us where they will most likely be, which puts us one step closer to finding a solution."

Cars built in the last decade have been shown to be safer than older models, including in the most common types of crashes - frontal collisions. However, a new study conducted by researchers at the University of Virginia's Center for Applied Biomechanics shows that women wearing seat belts are significantly more likely to suffer injury than their male counterparts.

Belted female auto occupants have 73% greater odds of being seriously injured in frontal car crashes compared to belted males (after controlling for collision severity, occupant age, stature, body mass index and vehicle model year). The difference in risk is greatest for injury to the lower extremities, but also occurs with several other types of injury.

"Until we understand the fundamental biomechanical factors that contribute to increased risk for females, we'll be limited in our ability to close the risk gap," said Jason Forman, a principal scientist with the Center for Applied Biomechanics. "This will take substantial effort, and in my view the National Highway Traffic Safety Administration does not have the resources needed to address this issue."

Additionally, vehicle occupants age 66 and older continue to be particularly susceptible to thoracic injury, likely resulting from increased fragility of the ribcage with advanced age.

The good news is that newer automobiles have tended to exhibit a decreased risk of injury overall. Specifically, risk has decreased for skull fractures, cervical spine injury and abdominal injury. Injury risks to the knee-thigh-hip region and the ankle are also significantly reduced. The risk of sternum fractures and serious rib fractures, however, has not been significantly reduced.

The study, published this week in the journal Traffic Injury Prevention, is an analysis of crash and injury data compiled from the National Automotive Sampling System Crashworthiness Data System for the years 1998 to 2015. These data come from a sample of police-reported crashes in the U.S.

"For belted occupants in frontal collisions, substantial reductions in injury risk have been realized in many body regions in recent years," Forman said. "These results provide insight into where advances in the field have made gains in occupant protection, and what injury types and risk factors remain to be addressed."

This study focused on frontal-impact crashes with belted occupants, aged 13 and older. The data included nearly 23,000 front-end crashes involving more than 31,000 occupants, and a nearly equal number of females and males. Pregnant women who were past the first trimester were not included.

RICHLAND, Wash. July 10, 2019 - The goal of the research, published July 11 in the journal Nature, was to engineer artificial proteins to self-assemble on a crystal surface by creating an exact match between the pattern of amino acids in the protein and the atoms of the crystal. The ability to program these interactions could enable the design of new biomimetic materials with customized colors, chemical reactivity or mechanical properties, or to serve as scaffolds for nano-scale filters, solar cells or electronic circuits.

"Biology has an amazing ability to organize matter from the atomic scale all the way up to blue whales," said co-first author Harley Pyles, a graduate student at the UW Medicine's Institute for Protein Design. "Now, using protein design, we can create brand new biomolecules that assemble from atomic- to millimeter-length scales. In this case, mica ? a naturally occurring crystal ? is acting like a big Lego® baseplate on top of which we are assembling new protein architectures."

The design of the new mineral-binding molecules was inspired by proteins that interact with ice. At the molecular scale, ice is flat and contains an atomically precise pattern of rigid water molecules. In nature, proteins match these patterns to enable them to stick to the ice.

The team used computational molecular design to engineer new proteins with customized patterns of electrical charge on their surfaces, as if they were nano-size Lego® blocks perfectly matched to the mica baseplate. Synthetic genes encoding these designer proteins were placed inside bacteria, which then mass produced the proteins in the laboratory.

The researchers found that different designs formed different patterns on the mica surface. By redesigning parts of the proteins, the team was able to produce honeycomb lattices in which they could digitally tune the diameters of the pores by just a few nanometers, which is about the width of a single DNA double helix molecule.

"This is a milestone in the study of protein-material interfaces," said David Baker, director of the IPD, a professor of biochemistry at the University of Washington School of Medicine and co-senior author of the research. "We achieved an unprecedented degree of order by designing units that self-assemble into aligned rows of nanorods, precise hexagonal lattices and exquisite single-molecule-wide nanowires."

The research was enabled by the use of atomic force microscopy, which uses a tiny needle to map molecular surfaces, much like how the needle from a record player reads information in the grooves of a vinyl record. The AFM results show that the architectures formed by the proteins are controlled by a subtle balance between the designed interactions with the mica surface and forces that only appear when large numbers of proteins act in concert, like logs on a river.

"Even though we designed specific atomic-level interactions, we get these structures, in part, because the proteins are crowded out by the water and are forced to pack together," said James De Yoreo, a materials scientist at PNNL and co-director of NW IMPACT, a joint research endeavor between PNNL and the UW to power discoveries and advancements in materials. "This was unexpected behavior and demonstrates that we need to better understand the role of water in ordering proteins in molecular-scale systems."

Being able to create functional protein filaments and lattices from scratch could also allow creation of entirely novel materials, unlike any found in nature. The findings could lead to new strategies for synthesizing semiconductor and metallic nanoparticle circuits for photovoltaic or energy storage applications. Or alternatively, the protein honeycombs could be used as extremely precise filters, according to co-first author Shuai Zhang, a postdoctoral researcher at PNNL. "The pores would be small enough to filter viruses out of drinking water or filter particulates out of air," said Zhang.

Design and synthesis of honeycomb-lattice forming proteins was supported by DOE's Office of Science, and AFM imaging and analysis was supported by The Center for the Science of Synthesis Across Scales, a DOE-supported Energy Frontier Research Center. Protein nanorod and nanowire design and synthesis were supported by the IPD Research Gift Fund, Michelson Medical Research Foundation, and Protein Design Initiative Fund. Development of AFM imaging protocols was supported by Materials Synthesis and Simulations Across Scales, an internally funded initiative at PNNL.

Robots are good at making identical repetitive movements, such as a simple task on an assembly line. (Pick up a cup. Turn it over. Put it down.) But they lack the ability to perceive objects as they move through an environment. (A human picks up a cup, puts it down in a random location, and the robot must retrieve it.) A recent study was conducted by researchers at the University of Illinois at Urbana-Champaign, NVIDIA, the University of Washington, and Stanford University, on 6D object pose estimation to develop a filter to give robots greater spatial perception so they can manipulate objects and navigate through space more accurately.

While 3D pose provides location information on X, Y, and Z axes--relative location of the object with respect to the camera--6D pose gives a much more complete picture. "Much like describing an airplane in flight, the robot also needs to know the three dimensions of the object's orientation--its yaw, pitch, and roll," said Xinke Deng, doctoral student studying with Timothy Bretl, an associate professor in the Dept. of Aerospace Engineering at U of I.

And in real-life environments, all six of those dimensions are constantly changing.

"We want a robot to keep tracking an object as it moves from one location to another," Deng said.

Deng explained that the work was done to improve computer vision. He and his colleagues developed a filter to help robots analyze spatial data. The filter looks at each particle, or piece of image information collected by cameras aimed at an object to help reduce judgement errors.

"In an image-based 6D pose estimation framework, a particle filter uses a lot of samples to estimate the position and orientation," Deng said. "Every particle is like a hypothesis, a guess about the position and orientation that we want to estimate. The particle filter uses observation to compute the value of importance of the information from the other particles. The filter eliminates the incorrect estimations.

"Our program can estimate not just a single pose but also the uncertainty distribution of the orientation of an object," Deng said. "Previously, there hasn't been a system to estimate the full distribution of the orientation of the object. This gives important uncertainty information for robot manipulation."

The study uses 6D object pose tracking in the Rao-Blackwellized particle filtering framework, where the 3D rotation and the 3D translation of an object are separated. This allows the researchers' approach, called PoseRBPF, to efficiently estimate the 3D translation of an object along with the full distribution over the 3D rotation. As a result, PoseRBPF can track objects with arbitrary symmetries while still maintaining adequate posterior distributions.

"Our approach achieves state-of-the-art results on two 6D pose estimation benchmarks," Deng said.

CLEMSON, South Carolina -- A team of Clemson University scientists has achieved a breakthrough in the genetics of senescence in cereal crops with the potential to dramatically impact the future of food security in the era of climate change.

The collaborative research, which explores the genetic architecture of the little understood process of senescence in maize (a.k.a. corn) and other cereal crops, was published in The Plant Cell, one of the top peer-reviewed scientific journals of plant sciences. Rajan Sekhon, a plant geneticist and an assistant professor in the College of Science's department of genetics and biochemistry, is the lead and corresponding author of the paper titled "Integrated Genome-Scale Analysis Identifies Novel Genes and Networks Underlying Senescence in Maize."

"Senescence means 'death of a cell or an organ in the hands of the very organisms it is a part of,' " Sekhon said. "It happens pretty much everywhere, even in animals. We kill the cells we don't need. When the weather changes in fall, we have those nice fall colors in trees. At the onset of fall, when the plants realize that they cannot sustain the leaves, they kill their leaves. It is all about the economy of energy."

As a result, the leaves die off after their show of color. The energy scavenged from the leaves is stored in the trunk or roots of the plant and used to quickly reproduce leaves next spring. This makes perfect sense for trees. But the story is quite different for some other edible plants, specifically cereal crops like maize, rice and wheat.

"These crops are tended very carefully and supplied excess nutrients in the form of fertilizers by the farmers," Sekhon said. "Instead of dying prematurely, the leaves can keep on making food via photosynthesis. Understanding the triggers for senescence in crops like maize means scientists can alter the plant in a way that can benefit a hungry world."

Sekhon, whose research career spans molecular genetics, genomics, epigenetics and plant breeding, established his lab in 2014 as an assistant professor. He has played a key role in the development of a "gene atlas" widely used by the maize research community. He has published several papers in top peer-reviewed journals investigating the regulation of complex plant traits.

"If we can slow senescence down, this can allow the plant to stay green - or not senesce - for a longer period of time," Sekhon said. "Plant breeders have been selecting for plants that senesce late without fully understanding how senescence works at the molecular level."

These plants, called "stay-green," live up to their name. They stay green longer, produce greater yields and are more resilient in the face of environmental factors that stress plants, including drought and heat.

But even with the existence of stay-green plants, there has been little understanding about the molecular, physiological and biochemical underpinnings of senescence. Senescence is a complex trait affected by several internal and external factors and regulated by a number of genes working together. Therefore, off-the-shelf genetic approaches are not effective in fully unraveling this enigmatic process. The breakthrough by Sekhon and his colleagues was the result of a systems genetics approach.

Sekhon and the other researchers studied natural genetic variation for the stay-green trait in maize. The process involved growing 400 different maize types, each genetically distinct from each other based on the DNA fingerprint (i.e., genotype), and then measuring their senescence (i.e., phenotype). The team then associated the "genotype" of each inbred line with its "phenotype" to identify 64 candidate genes that could be orchestrating senescence.

"The other part of the experiment was to take a stay-green plant and a non-stay-green plant and look at the expression of about 40,000 genes during senescence," Sekhon said. "Our researchers looked at samples every few days and asked which genes were gaining expression during the particular time period. This identified over 600 genes that appear to determine whether a plant will be stay-green or not.

"One of the big issues with each of these approaches is the occurrence of false positives, which means some of the detected genes are flukes, and instances of false negatives, which means that we miss out on some of the causal genes."

Therefore, Sekhon and his colleagues had to painstakingly combine the results from the two large experiments using a "steams genetics" approach to identify some high-confidence target genes that can be further tested to confirm their role in senescence. They combined datasets to narrow the field to 14 candidate genes and, ultimately, examined two genes in detail.

"One of the most remarkable discoveries was that sugars appear to dictate senescence," Sekhon said. "When the sugars are not moved away from the leaves where these are being made via photosynthesis, these sugar molecules start sending signals to initiate senescence."

However, not all forms of sugar found in the plants are capable of signaling. One of the genes that Sekhon and colleagues discovered in the study appears to break complex sugars in the leaf cells into smaller sugar molecules - six-carbon sugars like glucose and fructose - that are capable of relaying the senescence signals.

"This is a double whammy," Sekhon said. "We are not only losing these extra sugars made by plants that can feed more hungry mouths. These unused sugars in the leaves start senescence and stop the sugars synthesis process all together."

The implications are enormous for food security. The sugars made by these plants should be diverted to various plant organs that can be used for food.

"We found that the plant is carefully monitoring the filling of the seeds. That partitioning of sugar is a key factor in senescence. What we found is there is a lot of genetic variation even in the maize cultivars that are grown in the U.S."

Some plants fill seeds and then can start filling other parts of the plant.

"At least some of the stay-green plants are able to do this by storing extra energy in the stems," Sekhon said. "When the seed is harvested, whatever is left in the field is called stover."

Stover can be used as animal feed or as a source of biofuels. With food and energy demand increasing, there is a growing interest in developing dual-purpose crops which provide both grain and stover. As farmland becomes scarce, plants that senesce later rise in importance because they produce more overall energy per plant.

The genes identified in this study are likely performing the same function in other cereal crops, such as rice, wheat and sorghum. Sekhon said that the next step is to examine the function of these genes using mutants and transgenics.

"The ultimate goal is to help the planet and feed the growing world. With ever-worsening climate, shrinking land and water, and increasing population, food security is the major challenge faced by mankind," Sekhon said.

Individually, ants have only so much strength and intelligence. However, as a colony, they can use complex strategies to complete sophisticated tasks and evade larger predators.

At EPFL, robotics researchers in Professor Jamie Paik's Laboratory have reproduced this phenomenon, developing tiny robots that display minimal physical intelligence on an individual level but that are able to communicate and act collectively. Despite being simple in design and weighing only 10 grams, each robot has multiple locomotion modes to navigate any type of surface. Collectively, they can quickly detect and overcome obstacles and move objects much larger and heavier than themselves. The related research has been published in Nature.

Robots inspired by trap-jaw ants

These three-legged, T-shaped origami robots are called Tribots. They can be assembled in only a few minutes by folding a stack of thin, multi-material sheets, making them suitable for mass production. Completely autonomous and untethered, Tribots are equipped with infrared and proximity sensors for detection and communication purposes. They could accommodate even more sensors depending on the application.

"Their movements are modeled on those of Odontomachus ants. These insects normally crawl, but to escape a predator, they snap their powerful jaws together to jump from leaf to leaf," says Zhenishbek Zhakypov, the first author. The Tribots replicate this catapult mechanism through an elegant origami design that combines multiple shape-memory alloy actuators. As a result, a single robot can produce five distinct locomotion gaits: vertical jumping, horizontal jumping, somersaulting to clear obstacles, walking on textured terrain and crawling on flat surfaces - just like these creatively resilient ants.

Roles: leader, worker and explorer

Despite having the same anatomy, each robot is assigned a specific role depending on the situation. 'Explorers' detect physical obstacles in their path, such as objects, valleys and mountains. After detecting an obstacle, they inform the rest of the group. Then, the 'leader' gives the instructions. The 'workers,' meanwhile, pool their strength to move objects. "Each Tribot, just like Odontomachus ants, can have different roles. However, they can also take on new roles instantaneously when faced with a new mission or an unknown environment, or even when other members get lost. This goes beyond what the real ants can do," says Paik.

Future applications

In practical situations, such as an emergency search mission, Tribots could be deployed en masse. And thanks to their multi-locomotive and multi-agent communication capabilities, they could locate a target quickly over a large surface without relying on GPS or visual feedback. "Since they can be manufactured and deployed in large numbers, having some 'casualties' would not affect the success of the mission," adds Paik."

"With their unique collective intelligence, our tiny robots can demonstrate better adaptability to unknown environments; therefore, for certain missions, they would outperform larger, more powerful robots."

Research for the benefit of food security: A new line of barley achieves good crop yields even under poor environmental conditions. It has been bred by a research team from Martin Luther University Halle-Wittenberg (MLU), which crossed a common variety with various types of wild barley. The researchers then planted the new lines of barley in five very different locations around the world, observed the growth of the plants and analysed their genetic make-up. As the team reports in "Scientific Reports", some of the plants were not only more resistant to heat and drought, but in many cases achieve higher yields than local varieties.

Barley, along with wheat and rice, is one of the most important cereals for human nutrition. "The demand for food is increasing worldwide, which is why the cultivation of these cereals must generate reliable crop yields. However, climate change is taking its toll on cultivation conditions worldwide and plants have to be fertilized and irrigated more frequently," says plant scientist Professor Klaus Pillen from MLU. His research team is studying how to improve common cereal varieties for years. Their approach is to cross certain industrially used barley varieties with wild barley. "Wild barley has adapted to adverse environmental conditions over millions of years. It still has a rich biodiversity today," explains Pillen. The idea is to combine the advantageous properties of both cereals.

For the study, the research team crossed a typical barley variety with 25 types of wild barley. This resulted in 48 genetically different plant lines, which the research team planted at five very different locations around the world: Dundee (UK), Halle (Germany), Al Karak (Jordan), Dubai (United Arab Emirates) and Adelaide (Australia). Each of these places has its own environmental conditions: Australia and Dubai suffer from very salty, dry soils, Al Karak and Dubai from heat and drought. In Germany and UK, fields always receive additional nitrogen fertilizer in order to increase crop yields. During the cultivation period, the scientists observed the growth of the plants under environmental stress and compared the results to native varieties from a control group. "We then selected plants from our cultivation that grew particularly well on site and examined their genetic material more closely," continues Pillen. The researchers wanted to draw conclusions about the interaction between genes, the environment and crop yields.

"Our study also shows that the timing of plant development is extremely important. This ensures maximum crop yields even under unfavourable environmental conditions," says Pillen. By this he means, for example, the length of daylight, which varies according to latitude: the closer a place is to the equator, the shorter the duration of daily sunshine during spring and summer. This has a big impact on the development of the plants. "In northern Europe, it is more advantageous for plants to flower later. The closer you get to the equator, it's better for plants to develop much faster," explains Pillen. Based on genetic analyses of the plants, the team was also able to draw conclusions about the gene variants that cause this acceleration or delay in development.

Knowing which gene variants are advantageous for which geographical regions allows plants that are particularly well adapted to the local conditions to be crossed, bred and cultivated according to the modular principle. And this is all well worth the effort: even under adverse conditions, Halle's best barley produced up to 20 percent higher yields than native plants.

In follow-up projects, the research team would like to further investigate the genetic material in order to gain more detailed insights into the stress tolerance of plants. The findings from the new study can, in principle, also be applied to other cereal varieties, such as wheat and rice.

Sustainable means of mobility are becoming ever more popular. In Switzerland, around 15,000 people have registered with the online platform carvelo2go, which hires out electric cargo bikes. The use of this sharing service in the Basel area is now the subject of scientific investigation. Despite strong growth in member numbers, there are still fundamental barriers. The study by the University of Basel indicates ways that sharing providers and public authorities can promote the use of environmentally friendly cargo bikes.

The diesel scandal and the climate protection movement "Fridays for Future" have fueled debate around sustainable forms of transportation. Currently, electric scooters are attracting widespread attention and the hope is that they can make a contribution to the issue of environmentally friendly mobility. E-cargo bikes are proving highly popular for the transport of purchased goods, children and even moving crates. They have plenty of storage space, and their electric motor makes it easy to transport loads of up to 100 kg for local trips.

Since 2016, the city of Basel has been cooperating with the carvelo2go initiative, which offers electric cargo bikes for rental. This service is currently used by more than 2,000 people in Basel and adjoining municipalities. But who are these users?

Main users: "Generation Sharing"

In 2017, the University of Basel's Sustainability Research Group carried out an online survey of all users in the Basel area in cooperation with carvelo2go. The control group consisted of non-members. The final sample comprised about 300 subjects belonging to four groups: active, inactive, potential users and people who could not imagine renting a cargo bike.

"Our survey shows that the active users often ride bikes day-to-day as well," says Ann-Kathrin Hess, first author of the study. "The average age is 39.6 and they are 60% male. What's more, a large number of carvelo2go members do not own a car and already use a car-sharing service." Hess adds: "Familiarity with the sharing principle seems to be a key factor in switching to e-cargo bike sharing."

Reservations and barriers

Meanwhile, the inactive members do not (yet) or no longer use the service because they have access to comparable means of transportation. Either they own their own cargo bike or bike trailer, or they use other rental options. Potential members do not use carvelo2go yet, but can imagine themselves doing so in the future. This group contains a balanced mix of men and women.

In addition, the study analyzed people who could not imagine renting a cargo bike. "These individuals are afraid to cycle because of the many cars in the city and believe that bike paths are too unsafe," says co-author Dr. Iljana Schubert. "They're also concerned by the speed of the electric drive support. In comparison with the other three groups, these people primarily use cars and public transport for day-to-day mobility."

Structural support

The study indicates ways in which e-cargo bike sharing could be made even more user-friendly: more stations, more cargo bikes at busy locations and a more flexible pick-up and return structure. The study found that the city could help to counter concerns and reservations by investing more in bicycle infrastructure. Wider, safer bike paths and special parking spots for cargo bikes would provide more room for this means of transport.

Carvelo2go is the first e-cargo bike sharing project in the world. The initiative was launched in 2015 by the TCS Mobility Academy and the Engagement Migros fund. The rental works in the same way as the Mobility car-sharing service: cargo bikes can be hired by the hour or the day. Pick-up and return is arranged through "hosts", who include small businesses and post offices. Hosts manage the keys and charge the batteries. In return, they can advertise on the cargo box and use the bike for their own purposes for 25 hours each month.

Since the introduction of carvelo2go in Basel, the number of users has strongly increased each year. There are currently 2,192 registered members in Basel and surrounding municipalities. A total of 26 cargo bikes are available for hire at 23 host sites.

The study is a continuation of a hypothesis that Unto K. Laine, Professor Emeritus, published three years ago on the origin of the sounds heard during the displays of the Northern Lights. His theory postulated that the sounds are generated when a magnetic storm causes charges in the temperature inversion layer of the lower atmosphere, to be discharged at an altitude of 70 to 80 metres.

A recent research paper presented by Laine at the ICSV26 congress in Montreal provides a more detailed account of the sound generation. According to this study, when the Northern Lights occur, the spectrum of the temporal envelope of the crackling noise (or in other words, the rapid changes in the sound amplitude) contain frequencies of the Schumann resonances.

The Schumann resonances refer to the low-frequency electromagnetic resonances occurring around the Earth, the strongest of them being below 50 Hz. Laine has now observed that these resonances generated similar rhythmic structures in all the measured crackling sounds.

'Previous international research has shown that a geomagnetic storm occurring during the Northern Lights reinforces the Schumann resonances. For the first time, such resonances have been found to activate the sound generation mechanism in the temperature inversion layer at altitudes of between 70 to 80 metres where the accumulated electric charges give rise to corona discharges and crackling sounds. In addition to the nine lowest Schumann resonances, the spectra also include their difference and sum frequencies or in other words, distortion components. This non-linearity also lends support to the hypothesis of auroral sounds generation,' Laine says.

The research material consisted of 25 sound events measured on the ground in September 2001 and in March 2012 in Southern Finland, during the display of active Northern Lights. Although the measurements were conducted at different locations using various equipment, the results nevertheless point to the same direction.

A German-Swiss team around Professor Oliver Daumke from the MDC has investigated how a protein of the dynamin family deforms the inner mitochondrial membrane. The results, which also shed light on a hereditary disease of the optic nerve, have been published in Nature.

Mitochondria are the powerhouses of our cells, generating energy in the form of chemical compounds such as ATP. To do this job effectively, mitochondria have a characteristic organisation: In addition to an outer membrane, they have an inner membrane with many invaginations. On this inner membrane are all the enzymes essential to the production of ATP.

Mitochondria are not rigid organelles

"We were interested in how mitochondria acquire and maintain their characteristic shape," says Professor Oliver Daumke, leader of the MDC research group Structural Biology of Membrane-Associated Processes and one of the two senior authors of the study published in Nature. "The fact is that mitochondria are not rigid organelles - they are continuously dividing and fusing with each other." One result of this process is that damaged sections are removed.

"But the mitochondria don't always function so perfectly," explains Dr. Katja Faelber from the Crystallography Department at the MDC, one of the study's two first authors. "Many neurodegenerative diseases, such as Alzheimer's and Parkinson's disease, are the result of an imbalance between mitochondrial fission and fusion, which causes neurons to slowly die off."

A molecular machine to reorganize the mitochondrial membrane

Key players in the remodelling of the mitochondrial membrane are the mitochondrial genome maintenance protein 1 (Mgm1) in yeats and the optic atrophy protein 1 (OPA1) in humans. Mutations in the gene for OPA1 lead to a hereditary disease of the optic nerve known as optic atrophy, one of the most common causes of congenital blindness.

"Mgm1 and OPA1 are located on the inner mitochondrial membrane, particularly close to the characteristic invaginations," explains Oliver Daumke. Here the proteins function as molecular machines, converting chemical energy into mechanical energy.

Prior to this study, it was already known that the proteins consist of several sub-units: of the GTPase domain, which functions as the actual motor, of the BSE (bundle signalling element) domain, which acts as a lever, and the stalk. "We were especially interested in the stalk, because Mgm1 assembles via this unit into filament-like structures," says Oliver Daumke. These filaments are essential for the function of the molecular machine and consequently for the deformation of the membrane. Without them, the machine would not work.

Using different techniques to build a molecular model

To understand in more detail how Mgm1 stabilises the invaginations and controls the continuous remodelling of the inner mitochondrial membranes, the scientists at the MDC determined the structure of the protein via X-ray crystallography. "Using this method, we generated a three-dimensional atomic model of the Mgm1 protein," explains Katja Faelber.

The structural biology team in Berlin then cooperated with the group of Professor Werner Kühlbrandt at the Max Planck Institute of Biophysics in Frankfurt am Main, who examined the protein using cryo-electron microscopy. "This technique results in lower resolution structures, but in contrast to X-ray crystallography it enabled us to study Mgm1 in its membrane-bound form," Katja Faelber says.

This led to the discovery of a fourth, previously unknown domain of Mgm1, which they named the 'paddle'. "Via this elongated domain Mgm1 attaches itself to the inner mitochondrial membrane," explains Oliver Daumke. "Additionally, we also identified the contact sites in the stalk that are essential for the arrangement of Mgm1 into filaments." This gave the team all the puzzle pieces they needed to computer-simulate the processes occurring on the membrane.

Mutations in Mgm1 lead to a collapse of the mitochondria

To verify whether the identified contact surfaces were critical for the stabilisation of the inner mitochondrial membrane, the group led by Professor Martin van der Laan at Saarland University Medical Center in Homburg replaced certain amino acids in these regions. "Indeed, the protein lost its function," says Oliver Daumke. "The mitochondria did no longer form the characteristic invaginations of the inner membrane and did not fuse with each other." Many small mitochondrial fragments were left behind, he adds.

Finally, the group of Professor Aurel Roux at the University of Geneva observed in real time how Mgm1 attaches to membranes using fluorescence microscopy. "The surprising new observation was that the protein binds not only to the outside of artificial membrane tubes, but also to the inside," says Katja Faelber. "This has never been described for any other member of the dynamin superfamily so far. In fact, this geometry corresponds to that of the invaginations of the inner membrane."

Improving our understanding of genetic blindness

The team is optimistic that the new findings will benefit medical research. "The results of our study can explain which processes are impaired throughout the course of optic atrophy disease in the eye - how mutations in the OPA1 gene cause the dysfunction of the protein," says Oliver Daumke. He adds that perhaps one day, this knowledge will make it possible to find a therapy. (bro)

Terahertz (THz) radiation is a bit like a treasure chest that resists being opened fully. Residing in the electromagnetic spectrum between the infrared and microwave regions, THz radiation combines a range of properties that are ideal with a view to applications. It provides a window to unique spectroscopic information about molecules and solids, it can penetrate non-conducting materials such as textiles and biological tissue, and it does so without ionising -- and hence damaging -- the object, or subject, under study. This opens up intriguing prospects for non-invasive imaging and non-destructive quality control, among other applications. But whereas there is no shortage in ideas for potential uses, their implementation is hampered by a lack of practical technologies for generating and detecting THz radiation.

Therefore the excitement as Lorenzo Bosco, Martin Franckié and colleagues from the group of Jérôme Faist at the Institute for Quantum Electronics of ETH Zurich reported now the realization of a THz quantum cascade laser that operates at a temperature of 210 K (-63 °C). That is the highest operational temperature achieved so far for this type of device. More importantly, this is the first time that operation of such a device has been demonstrated in a temperature regime where no cryogenic coolants are needed. Instead, Bosco et al. used a thermoelectric cooler, which is much more compact, cheaper and easier to maintain than cryogenic equipment. With this advance, they removed the main obstacles on the route to various practical applications.

A cascade towards applications

Quantum cascade lasers (QCLs) have long been established as a natural concept for THz devices. Like many lasers that are widely used as sources of light in the visible-to-infrared frequency region, QCLs are based on semiconductor materials. But compared to typical semiconductor lasers used, for instance, in barcode readers or laser pointers, QCLs operate according to a fundamentally different concept to achieve light emission. In short, they are built around repeated stacks of precisely engineered semiconductor structures (see the figure, panel c), which are designed such that suitable electronic transitions take place in them (panel d).

QCLs have been proposed in 1971, but they were first demonstrated only in 1994, by Faist and colleagues, then working at Bell Laboratories (US). The approach has proved its value in a board range of experiments, both fundamental and applied, mainly in the infrared region. The development of QCLs for THz emission has made substantial advances, too, starting from 2001. Widespread use has been hindered though by the requirement for cryogenic coolants -- typically liquid helium -- which adds substantial complexity and cost, and makes devices large and less mobile. Progress towards operation of THz QCLs at higher temperatures got essentially stuck seven years ago, when operation of devices at around 200 K (-73 °C) was achieved.

Barrier crossed

Reaching 200 K was an impressive feat. That temperature, however, is just below the mark where cryogenic techniques could be replaced with thermoelectric cooling. That the record temperature did not move since 2012 also meant that some sort of 'psychological barrier' started to go up -- many in the field started to accept that THz QCLs would always have to operate in conjunction with a cryogenic cooler. The ETH team has now broken down that barrier. Writing in Applied Physics Letters, they present a thermoelectrically cooled THz QCL, operating at temperatures of up to 210?K. Moreover, the laser light emitted was strong enough that it could be measured with a room-temperature detector. This means that entire setup worked without cryogenic cooling, further strengthening the potential of the approach for practical applications.

Bosco, Franckié and their co-workers managed to remove the 'cooling barrier' due to two related achievements. First, they used in the design of their QCL stacks the simplest unit structure possible, based on two so-called quantum wells per period (see the figure, panel d). This approach has been known to be a route to higher temperatures of operation, but at the same time this two-well design is also extremely sensitive to smallest changes in the geometry of the semiconductor structures. Optimizing performance relative to one parameter can lead to degradation relative to another. With systematic experimental optimization being not a viable option, they had to rely on numerical modelling.

This is the second area where the group has made substantial progress. In recent work, they have established that they can accurately simulate complex experimental QCL devices, using an approach known as nonequilibrium Green's function model. The calculations have to be carried out on a powerful computer cluster, but they are sufficiently efficiently that they can be used to search systematically for optimal designs. The group's ability to accurately predict the properties of devices -- and to fabricate devices according to precise specifications -- gave them the tools to realize a series of lasers that consistently work at temperatures that could be reached with thermoelectrical cooling (see the figure, panels a and b). And the approach is by no means exhausted. Ideas for pushing the operational temperature further up exist in the Faist group, and preliminary results do look promising.

Filling the THz gap

The first demonstration of a terahertz quantum cascade laser operating without cryogenic cooling constitutes an important step towards filling the 'THz gap', which has long existed between the mature technologies for microwave and infrared radiation. With no moving parts or circulating liquids involved, the sort of thermoelectrically cooled THz QCLs now introduced by the ETH physicists can be more easily applied and maintained outside the confines of specialised laboratories -- lifting further the lid of the 'THZ treasure chest'.