Tech

WINSTON-SALEM, N.C. - Aug. 6, 2019 - The internet can serve as a pathway to diagnosis and care for people who suspect they have a rare condition that has not been identified by their physicians, according to a study by researchers at Wake Forest School of Medicine, part of Wake Forest Baptist Health.

"Rare diseases, especially inherited ones, are often not correctly diagnosed by primary care physicians and even specialists because they are so uncommon, and a provider who does have expertise may be located very far from the patient," said the study's lead author, Anthony J. Bleyer, M.D., professor of nephrology at the medical school. "While online searches can frequently fail to provide relevant or correct health information, the internet does offer those with rare disorders a way to find the rare specialists interested in a particular condition and obtain accurate information about it."

The study, published in the current issue of the Genetics in Medicine, the official journal of the American College of Medical Genetics and Genomics, analyzed 665 referrals made from 1996 to 2017 to a Wake Forest School of Medicine research center specializing in autosomal dominant tubulointerstitial kidney disease (ADTKD), a group of rare inherited conditions that gradually cause kidneys to stop working.

Among the referrals, 40 percent were from health care providers at academic medical centers, 33 percent were from non-academic practitioners and 27 percent were self-referrals from individuals or family members with concerns about but no diagnosis of inherited kidney disease who contacted the center directly through its website without guidance or assistance from a health care provider.

Genetic testing results were positive (indicating the presence of ADTKD) in 27 percent of the cases referred by academic centers, 25 percent of those referred by non-academic providers and 24 percent of those who contacted the center directly.

"The similar percentages of positive results from the three types of referrals indicate that actively pursuing self-diagnosis using the internet can be successful," Bleyer said. "One-quarter of the families found to have ADTKD were diagnosed as result of direct contact with the center through the internet, which represents 42 families and 116 individuals who otherwise would have gone undiagnosed if a family member had not contacted us."

One of the study's limitations is that it examined data from only one center specializing in a single rare disorder.

Nonetheless, Bleyer said, the study highlights the importance of the internet as a resource for people with rare conditions.

"The availability of focused information about rare disorders on the internet may lead to increased diagnoses of these conditions," he said. "Centers interested in rare disorders should consider improving their online accessibility to the public."

Researchers at Stanford University have found that spraying a gel on the internal tissues of animals after cardiac surgery greatly reduces adhesions, fibrous bands that form between internal organs and tissues. Adhesions can cause serious, even fatal, complications.

The gel, developed at Stanford to deliver medications, was far more effective than adhesion prevention materials currently on the market, the researchers said. It appeared to be safe in the animal study.

"The difference between what we saw after using the gel and what we normally see after surgery was drastic," said Joseph Woo, MD, professor and chair of cardiothoracic surgery and the Norman E. Shumway Professor.

A paper describing the research published August 7 in Nature Biomedical Engineering. Woo and Eric Appel, PhD, an assistant professor of materials science and engineering, are the senior authors. Lyndsay Stapleton, a graduate student in bioengineering, is the lead author.

Adhesions form after 95% of surgeries. Some are harmless, but after abdominal surgeries, they can twist or compress the intestines, causing life-threatening blockages. Gynecological surgery can also lead to adhesions that cause infertility. In cardiac re-operations, common for those born with heart defects, adhesions increase the risk of complications.

Previous methods, lot of failures

Methods to prevent adhesions -- including animal membranes, sheets of rubber and mineral oil -- have existed for more 100 years, but they have mostly failed. Current adhesion barriers approved by the Food and Drug Administration are rarely used; they are difficult to deploy and are considered ineffective.

The Stanford researchers had long pondered a solution to the adhesion problem. But one day, when Stapleton was working with lab rats to develop an injectable therapy to reduce tissue damage following a heart attack, Appel suggested she try spraying a polymer-nanoparticle hydrogel onto the hearts and surrounding tissue after surgery to see if it reduced the formation of adhesions. Weeks later, when she operated on the animals again, she saw that no adhesions had formed.

"It was pretty striking," she said. "I thought, 'Oh wow, we could be onto something here.'"

The researchers decided to conduct a study. First, they formulated four additional gels with a range of properties. Then, after inducing heart attacks in rats, they randomly divided the animals into eight treatment groups: five that each received a different gel, two that received commercially available adhesion barriers and one that received no treatment.

Four weeks later, the rats that had received no treatment or either of the two commercial adhesion barriers had formed dense adhesions: Their hearts were connected to their chest walls. The rats that were treated with two of the five gels had formed moderate to dense adhesions. The rats treated with the other three gels fared much better, with very few adhesions. PNP 1:10, the gel Stapleton initially tried, completely prevented adhesions.

The researchers then tested PNP 1:10 in sheep, whose hearts are similar in size and shape to human hearts; they found similar results.

Like mayonnaise

PNP 1:10 was stiff enough to stick, but not so stiff it detached from the organs, Appel said. "It was sort of a Goldilocks sweet spot." He compared PNP 1:10 to mayonnaise: thick, but easily spreadable. That property allows it to be sprayed onto an organ but then immediately reform its original strength.

The gel also has the ideal tension between stickiness and slipperiness: "It covers all of the irregular surfaces of the heart, adhering to the tissues, but not to itself," Woo said.

And it's flexible, allowing the heart to beat: "The gel doesn't prevent tissues from moving around," Appel said. "It simply provides a physical barrier to keep them from sticking to each other."

PNP 1:10 dissolves and is absorbed by the body about two weeks after its application -- enough time for healing to occur, Appel said. PNP 1:10 is not approved for use in patients, but it is made of components that the Food and Drug Administration has approved. As part of the study, the researchers tested the rats to see if they showed any reaction to the gel; they saw no abnormalities in the surrounding tissues or in the blood.

The researchers next plan to try PNP 1:10 in abdominal surgery in rats. They hope to conduct human trials soon.

AMHERST, Mass. - Industry figures show the global rate of solar energy installations grew by 30 percent in one recent year, and the average cost of installing solar has fallen from $7 per watt to $2.8 per watt, making rooftop solar attractive to many more homeowners. But the progress of rooftop installations is often slowed by a shortage of trained professionals who must use expensive tools to conduct labor-intensive structure assessments one by one, say scientists at the University of Massachusetts Amherst.

To automate the process at present, say UMass Amherst College of Information and Computer Sciences (CICS) researchers led by Prashant Shenoy and Subhransu Maji, requires expensive three-dimensional aerial maps using LIDAR technology not available for many areas. Now their team is proposing a new, data-driven approach that uses machine learning techniques and widely available satellite images to identify roofs that have the most potential to produce cost-effective solar power.

Shenoy, Maji and colleagues are presenting their new "DeepRoof" tool this week at the 25th Association for Computing Machinery's Special Interest Group on Knowledge Discovery and Data Mining (ACM SIGKDD) conference in Anchorage, Alaska.

As Stephen Lee, a Ph.D. student at CICS and lead author, points out, "Solar potential estimation of a roof can substantially benefit homeowners deciding to adopt solar," but "current automated tools work only for cities and towns where LIDAR data is available, thereby limiting their reach to just a few places in the world."

The new data-driven DeepRoof approach takes advantage of recent advances in computer vision techniques and uses satellite imagery to accurately determine roof geometry, nearby structures and trees that affect the solar potential of the roof. "DeepRoof estimates can be used to identify ideal locations on the roof for installing solar panels," Lee adds.

The team trained DeepRoof using different roof shapes and sizes from six different cities to recognize and extract planar roof segments, Lee says. Results show that DeepRoof can identify the solar potential of roofs with 91 percent accuracy. Further, the tool can be scaled to automatically analyze satellite images of an entire city to identify all building roofs with the most solar potential.

Lekima is now a typhoon and has triggered warnings in the Philippines. NASA's Aqua satellite passed over the Northwestern Pacific Ocean and provided a visible image of the storm that shows a clear eye.

On Aug. 7, the Philippines' PAGASA service issued Tropical cyclone warning signal #1 for the Luzon provinces of Batanes and Babuyan group of islands.

On Aug. 7, 2019 at 12:55 a.m. EDT (0455 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite provided a visible image of Lekima that revealed a clear eye surrounded by a tight, circular band of powerful thunderstorms. Lekima also has a large band of thunderstorms that are feeding into the center from the south and east.

At 5 a.m. EDT (0900 UTC), Typhoon Lekima had maximum sustained winds near 85 knots (98 MPH/157 KPH). It was centered near 20.9 degrees north latitude and 127.7 degrees east longitude. That is 421 nautical miles south of Kadena Air Base, Okinawa island, Japan. Lekima was moving to the northwest and generating 25-foot high waves.

The Joint Typhoon Warning Center expects Lekima to continue moving northwest and strengthen to 125 knots (144 mph/232 kph), making it a Category 4 hurricane on the Saffir-Simpson hurricane wind scale. Lekima is expected to pass just north of northern Taiwan around August 9 and make landfall near Shanghai around August 12.

Many animals have to move around in their environment to find resources to live and reproduce.

Scientists have studied particular examples of this for many years but there are not many unifying frameworks to understand the general organising principles of animal movement.

This is especially true for animal collectives like ant colonies, whose individual routes as they search for food can look rather like a 'random walk'.

Now an inter-disciplinary team of scientists from the University of Bristol has developed a more fundamental model of collective movement that generates predictions for how individuals in tight-knit groups should move, considering how their movement behaviour should be optimised for colony-level success at finding food.

Their research is published today in the journal Royal Society Interface.

One of the authors, Dr Edmund Hunt from the University of Bristol's Department of Engineering Mathematics, said: "We recognised that the challenge an ant colony has to solve is the same as the challenge of a gambler trying to maximise long-term wealth.

"The mathematician John Kelly produced a result in 1956 showing that the way to do this is to bet on games in proportion to the probability of winning - so bet more money on more likely outcomes.

"The ants, then, should allocate their foragers (their 'wealth') to foraging areas according to how likely they are to find food there."

If this is indeed the best strategy, evolution should have produced movement behaviours that result in ants preferentially spending time in areas with high probability of payoff.

This results in mathematical models of movement that can be taken directly from statistical techniques originally developed in physics, to sample from complex probability distributions (complex 'environments').

The new framework for animal movement generates theoretical predictions for the way highly related collectives of organisms should move around, which in future can be examined experimentally in a wide range of biological systems.

Senior Researcher Changsoon Choi's team at DGIST Department of Smart Textile Convergence Research and Dr. Sungwoo Chun at Sungkyunkwan University (SKKU) developed artificial skin tactile sensors that can feel the similar pressure and vibration felt by human skin. The new sensors can detect more sensitive tactile than the existing ones, thus upgrading the related research further.

DGIST announced that Senior Researcher Changsoon Choi's team at Department of Smart Textile Convergence Research developed a new-concept artificial skin-based sensor that detects both pressure and vibration at the same time and effectively measures textile. Unlike existing sensors which only have pressure and temperature detection functions, the new sensors detect both pressure and vibration as well as convert the surface roughness of a matter into electrical signals to identify, with more sensitive and accurate detections of physical stimulations.

Among various sensory receptors of human, tactile sensors developed by the research team mimicked both 'Slow Adaptive (SA)' receptors that detect pressure and 'Fast Adaptive (FA)' receptors which detect the vibration and roughness. Using the principles of friction electricity generation, the research team especially developed and use the conversion of toughness from tactile into electrical energy signals.

The tactile sensors developed by the research team is in a flexible film-form that consist of an upper panel with human fingerprint-like micro patterns, middle panel with vibrator sensor mimicking FA receptors and a low panel with a pressure sensor mimicking SA receptors. Senior Researcher Dr. Choi's team especially used the principle of identifying roughness by measuring the vibration of friction electrical signals that are generated through object surface, to mimic FA receptors. Along with the sensors developed and the upper panel mimicking fingerprints, the team succeeded in classifying the roughness of 12 fabrics with more than 99% classification accuracy.

The sensors developed by Senior Researcher Choi's team opened the potential of artificial skin grafting for patients who need skin graft as a result of accidents to have real skin sense, which will bring huge effects to the related fields. Moreover, the new sensors will enable users to feel the senses through actual skin during a VR experience in a suit built with a tactile sensor.

Senior Researcher Changsoon Choi at the DGIST Department of Smart Textile Convergence Research said "I was inspired to develop new sensor while watching a movie where the main character was wearing a suit to experience virtual reality and feel his pain like in real. I hope that our research becomes the cornerstone for artificial skin-related and other researches."

Nickel is one of the most abundant elements on earth. It is hard, yet malleable, magnetic at room temperature, and a relatively good conductor of electricity and heat. Most notably, nickel is highly corrosion resistant, which provides for a variety of uses by industry.

However, a surprising discovery by a team of researchers at Texas A&M University has found that nickel not only corrodes, but does so in a way that scientists least expected.

The team was led by Dr. Michael Demkowicz, associate professor and graduate director in the Department of Materials Science and Engineering, and director of the Center for Research Excellence on Dynamically Deformed Solids at Texas A&M University.

Their work was published in the American Physical Society's Physical Review Materials journal in an article titled "Preferential Corrosion of Coherent Twin Boundaries in Pure Nickel Under Cathodic Charging."

A surprising observation

Like a finished jigsaw puzzle, materials are made of interlocking pieces. Microscopically, nickel is made of aggregates of small, tightly packed crystals or grains.

Corrosion preferentially attacks the joints, or "boundaries," between these grains. This phenomenon, known as intergranular corrosion, is a localized type of decay that occurs at the microscopic level, targeting the breakdown of materials at the edges of each of these boundaries, rather than at the outer surface of the material. As such, it weakens the material from the inside-out.

Until now, scientists thought that one special type of boundary, known as a coherent twin boundary, was resistant to corrosion. Surprisingly, the team discovered that nearly all the corrosion in their experiments occurred precisely on these boundaries.

Coherent twin boundaries are areas in which the material's internal structure pattern forms a mirror image of itself along a shared border. They occur when crystal formations on either side of an atom-wide border line up without disorder or disarray. These types of boundaries naturally occur during crystallization, but can also be the result of mechanical or thermal influence.

"Pure nickel is mostly corrosion resistant. But when we charged it at the cathodic (passive and lowest energy) side, which is even less likely to corrode, we did, surprisingly, see visible corrosion trenches on coherent twin boundaries," said Mengying Liu, graduate student at the Department of Materials Science and Engineering at Texas A&M and first author on the paper. "This finding will help engineers predict where corrosion is most likely to begin. It may even lead to the production of metals that corrode less."

A better understanding

The team's research not only provides engineers with vital insight into materials often utilized in situations that require corrosion resistance, but also offers a new perspective regarding intergranular corrosion along coherent twin boundaries.

For years, researchers have operated on the assumption that coherent twin boundaries resist corrosion. They have even worked to create metals that have more of these boundaries in an effort to reduce corrosion.

"This finding takes decades of assumptions on metal corrosion and flips them on their head," said Demkowicz. "In an effort to reduce corrosion, people have been making metals that contain as many coherent twin boundaries as possible. Now that entire strategy will have to be reconsidered."

Demkowicz believes the scientific insight provided by this study may be even more important than its technological applications. "It turns out the reasoning that previously led us to believe coherent twin boundaries are corrosion resistant is flawed," he said. "This work provides clues on how to improve our fundamental understanding of metal corrosion."

Salinity gradient energy is recognized as a promising candidate for the substitution of the traditional fossil fuels. Recently nanofluidic salinity gradient energy harvesting via ion channels or membranes has drawn increasing concerns due to the advances in materials science and nanotechnology, which could offer much higher power density than the macro reverse electrodialysis systems, indicating its potential to harvest the blue energy (about 1.4-2.6 TW) released by mixing seawater and river water as well as enhancing the power extracted for membrane-based osmotic heat engines.

Previous efforts focusing on the nanofluidic energy conversion system mainly deal with the isothermal conditions. Conventional viewpoint suggests that improving the membrane potential requires a larger temperature and a long channel length to guarantee a large selectivity and a high effective concentration difference. This intuitive judgement accounts for increasing temperature to achieve better performance. However, the transmembrane temperature difference is a very important, yet long-overlooked element that impacts the performance of the nanofuidic devices.

In a new research article published in the Beijing-based National Science Review, scientists at Huazhong University of Science and Technology, China present an anomalous temperature dependence in nanofluidic power generation. A negative temperature difference can significantly improve the membrane potential due to the impact of ionic thermal up-diffusion that promotes the selectivity and suppresses the ion concentration polarization, especially at the low concentration side, which results in dramatically enhanced electric power. Simple and efficient ways are also proposed to fabricate tunable ionic voltage sources and enhance salinity gradient energy conversion based on small nanoscale biochannels and mimetic nanochannels.

"Scientifically, we reveal the importance of a long-overlooked element, transmembrane temperature difference, in nanofluidic salinity gradient energy harvesting." Prof. Wei Liu said, "For applications and guidance, we can fabricate tunable ionic voltage sources, where the voltage is tuned by the temperature at the low concentration side and the internal resistance adjusted by the temperature at the high concentration side. And waste heat can be employed to enhance the power output and ionic flux by establishing transmembrane temperature difference to match the optimal transmembrane concentration intensity under the nanoscale biochannels and mimetic nanochannels."

A research team of fusion scientists succeeded in proving that ions can be heated by plasma oscillations driven by high-energy particles. This has been confirmed by performing a large-scale simulation with a newly developed hybrid-simulation program that links calculations for plasma oscillations, high-energy particles and ions. This research will accelerate studies of plasma self-heating for realizing fusion energy.

The fusion reaction between deuterium ion and tritium ion in a high-temperature plasma will be used in fusion reactors in the future. The high-energy alpha particles generated by the fusion reaction give their energy to the plasma, and this plasma self-heating maintains the high-temperature condition required for the fusion reaction. However, we have the problem that the heating of fuel ions is weak because the high-energy particles give most of their energy to electrons through collisions with the electrons. In order to increase the ion heating rate, it is proposed that ions can be heated by the plasma oscillations driven by the high-energy particles. However, this ion heating mechanism has not yet been confirmed.

The research team of Assistant Professor Hao Wang and Professor Yasushi Todo of the National Institutes of Natural Sciences (NINS) National Institute for Fusion Science (NIFS) conducted research on the ion heating by plasma oscillations using computer simulations.

Professor Todo previously developed a computer program that can simultaneously simulate the state of the plasma as a whole, which is treated as fluid, and the movement of high-energy particles in a plasma. This program, because it links and calculates the fluid and the particles, is called the hybrid-simulation program. It enables us to study the interaction between the plasma oscillations and the high-energy particles. The program is highly evaluated among fusion scientists, and several simulation studies using the program are now ongoing.

However, in order to study ion heating by plasma oscillations driven by high-energy particles, it is necessary to expand the hybrid-simulation program to simulate ion motions influenced by the plasma oscillations. The research team has succeeded in developing a new hybrid-simulation program by calculating ions in a plasma as particles and by linking the three kinds of calculations for the plasma oscillations, the high-energy particles, and the ions. Using the new hybrid-simulation program, they performed a large-scale simulation on the super computer regarding the plasma generated in the Large Helical Device (LHD). (On the LHD, we utilize the high-energy hydrogen particles that are inside the plasma to study plasma oscillations driven by high-energy particles.) The new hybrid simulation clearly shows that ions obtain energy from plasma oscillations excited by the high-energy particles. This indicates that the ion heating rate in a self-heating plasma can be increased by using the plasma oscillations.

Thus, the research team has proved the ion heating by plasma oscillations for the first time in the world. On the basis of the results of this study, the research on self-heating plasma for realizing fusion energy will be accelerated.

A phenomenon that makes coral spawn more than once a year is improving the resilience of the Great Barrier Reef.

The discovery was made by University of Queensland and CSIRO researchers investigating whether corals that split their spawning over multiple months are more successful at spreading their offspring across different reefs.

Dr Karlo Hock, from UQ's School of Biological Sciences, said coral mass spawning events are one of the most spectacular events in the oceans.

"They're incredibly beautiful," Dr Hock said.

"On Australia's Great Barrier Reef, all coral colonies typically spawn only once per year, over several nights after the full moon, as the water warms up in late spring."

Study co-author Dr Christopher Doropoulos from the CSIRO Oceans & Atmosphere said sometimes however, coral split their spawning over two successive months.

"This helps them synchronise their reproduction to the best environmental conditions and moon phases," he said.

"While reproductive success during split spawning may be lower than usual because it can lead to reduced fertilisation, we found that the release of eggs in two separate smaller events gives the corals a second and improved chance of finding a new home reef."

The research team brought together multi-disciplinary skills in modelling, coral biology, ecology, and oceanography, simulating the dispersal of coral larvae during these split spawning events, among the more than 3800 reefs that make up the Great Barrier Reef.

They looked at whether the split spawning events more reliably supply larvae to the reefs, as well as whether the ability to exchange larvae among the reefs is enhanced by them.

UQ's Professor Peter J. Mumby said split spawning events can increase the reliability of larval supply as the reefs tend to be better connected and have more numerous, as well as more frequent, larval exchanges.

"This means that split spawning can increase the recovery potential for reefs in the region.

"A more reliable supply of coral larvae could particularly benefit reefs that have recently suffered disturbances, when coral populations need new coral recruits the most.

"This will become more important as coral reefs face increasingly unpredictable environmental conditions and disturbances."

Dr Hock said the research also revealed that the natural processes of recovery can sometimes be more resilient than originally thought.

"However, even with such mechanisms in place, coral populations can only withstand so much pressure," he said.

"It all ends up being the matter of scale: any potential benefits from split spawning might be irrelevant if we don't have enough coral on these reefs to reproduce successfully.

"Mitigating well-established local and global threats to coral reefs - like river runoffs and carbon dioxide emissions - is essential for their continued survival."

Seeking social status is a central human motivation. Whether it's buying designer clothing, working the way up the job ladder, or making a conspicuous donation to charity, humans often seek and signal social status. Human cooperation and competition aren't mutually exclusive, they are two sides of the same coin. Christopher von Rueden from the University of Richmond and Daniel Redhead from the Max Planck Institute for Evolutionary Anthropology led a study to assess the relationship between men's cooperation and status hierarchy, over a period of eight years, in a community of Tsimane Amerindians in Amazonian Bolivia.

Among the Tsimane, status is informal and evident in who has more verbal influence during community meetings. Influential men in this community also enjoy greater health and have more surviving children. At three points over the eight-year period, the researchers asked men to rank other men within their community on their status and to report other men with whom they regularly cooperate, in terms of food-sharing or joint hunting, fishing, or horticultural labour. The researchers show that high status men gain more cooperation partners over time, and that men gain status over time by cooperating with men of higher status than themselves. By cooperating with high status individuals, one may gain valuable information, resources, or coalitional support that increases one's own status. Alternatively, cooperation with high status individuals may increase one's status by more effectively broadcasting generosity or other desirable attributes to other community members.

"The finding that status depends on cooperation provides insight into why human societies, particularly small-scale societies like the Tsimane, are relatively egalitarian compared to other primates", says von Rueden, joint-lead author of the study. "Humans allocate status based on the benefits we can provide to others, often more than on the costs we can inflict. This is in part because humans evolved greater interdependence, relying on each other for learning skills, producing food, engaging in mutual defence, and raising offspring. Individuals who can offer unique services in these contexts gain status. However, the transfer of information and resources from higher to lower status individuals, as well as the potential reputational benefits to cooperating with higher status individuals, may constrain or even erode status differentials. Status inequality is constrained when by cooperating, status-dissimilar individuals influence each other's statuses. This likely changed with the spread of agriculture ten thousand years ago, as human communities grew in size and began producing more private wealth. Widespread cooperation among community members becomes difficult as community size increases, and individuals with more wealth can lose incentive to cooperate with the non-wealthy outside of more market-based or coercive transactions. These processes limit upward mobility and fuel stratification by wealth class."

Daniel Redhead, joint-lead author of the study, adds: "This is one of the first longitudinal studies of social status. Our findings provide some of the first evidence that the relationship between cooperation and social status among humans is bidirectional. That is, humans - compared to other animals - give status to those who provide benefits to groups, and are thus more attracted to these individuals as cooperative partners. At the same time, individuals increase their own status by cooperating with such high-status. These findings provide empirical evidence that stresses the broader importance of social interdependence - be it food sharing, food production, friendship or advice - in shaping human behaviour, and that this interdependence makes the ways that we obtain social status quite distinct from other animals."

Trees are seen as saviors in an era of climate change. Via their leaves, they absorb carbon dioxide and transform the greenhouse gas into oxygen and biomass. According to estimates by the International Panel on Climate Change (IPCC), the Amazon rainforests absorb a quarter of the carbon dioxide that is released each year from the combustion of fossil fuels. To date, global climate models have assumed that this absorption capacity will also remain constant in the future.

"But there has been no proof of this to date", emphasizes Dr. Katrin Fleischer. "It is entirely possible that the absorption capacity will even decrease." The ecologist from the Professorship for Land Surface-Atmosphere Interactions at the Technical University of Munich worked together with ecologists and ecosystem modelers from 10 countries to investigate the extent to which the nutrient supply in the Amazon region limits the production of biomass.

14 models compared

In doing so, the team did pioneering scientific work: To date, nobody has investigated this connection in depth, says Fleischer: "Most ecosystem models which allow the future development of ecosystems to be simulated were developed for the temperate latitudes, where there is generally sufficient phosphorus. However, in many areas of the Amazon region, it is in short supply - the ecosystem is many million years old, and the soil is leached of nutrients."

In order to find out how the rainforest will react to an increase in atmospheric carbon dioxide concentration, the researchers selected 14 different ecosystem models. All models were then used to simulate biomass production for the next 15 years: first for the current carbon dioxide concentration of 400 ppm and in a second scenario for an increased concentration of 600 ppm.

Trees reaching their limit

The result: Additional carbon dioxide can be absorbed by the trees and transformed into biomass -- but only if sufficient phosphorous is available. If it becomes too scarce, the CO2 fertilization effect once again decreases. The various models, which take into account different factors, predict a decrease in the theoretically possible additional CO2 absorption in the second scenario of 50 percent on average - whereby some even predict a 100 percent decrease in absorption.

"This would mean that the rainforest has already reached its limit and would be unable to absorb any more carbon dioxide emissions caused by human kind", explains Fleischer. "If this scenario turns out to be true, the Earth's climate would heat up significantly faster than assumed to date."

How exactly the ecosystem would react, and whether the trees would succeed in absorbing additional phosphorous from the soil via enzymatic processes or by forming more roots which could bind and absorb the scarce nutrients needs to be researched in greater detail, summarizes the ecologist: "What's certain is that the tropical rainforests are not infinitely resilient CO2 sinks."

Some insects have the ability to manipulate plants to produce new organs known as galls, which manifest as abnormal growths on leaves, branches, or twigs. These galls provide insects and their offspring with food and shelter. Insects are also able to redirect the plant's nutrients, such as sugar, toward their galls, sometimes leaving the plant malnourished.

This competition for nutrition between the gall and the rest of the plant makes some of these insects a serious pest. In the 1800s, the galling insect phylloxera nearly decimated grapevine in Europe and another, the Hessian fly, caused a severe cereal shortage in the United States. Galling insects are master manipulators with the potential for widespread damage.

A team of scientists from the University of Toledo, University of Missouri and Northern Arizona University studied the relationship between galling insects and poplar trees and found that poplars that resisted these insects had higher levels of defense hormones. They also found that resistant poplars had a lower amount of a class of growth hormones called cytokinins. Last, they discovered that hormone changes in response to insect feeding are inherited.

This study, published in Molecular Plant-Microbe Interactions, is the most complete study to date about the role of hormones in galls, measuring 15 plant hormones belonging to 5 different classes. These findings can be used as a model for pest management and could help the agriculture and forestry industries better understand what makes plants resistant to pests.

A team of scientists from the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg and the Department of Physics at ETH Zurich in Switzerland, together with the Center for Computational Sciences of University of Tsukuba, has unraveled the light-induced electron-localization dynamics in transition metals at the attosecond timescale. The team investigated for the first time the many-body electron dynamics in transition metals before thermalization sets in. Their work has now appeared in Nature Physics.

The researchers used state-of-the art attosecond transient absorption spectroscopy (ATAS), an ultrafast method for examining electronic motion, to study the collective behavior of electrons in the transition metals Titanium (Ti) and Zirconium (Zr) and uncover the interplay between light absorption and electronic screening. Transition metals like these are key constituents of many materials with unconventional properties, for example high-temperature superconductors.

Those results are interpreted through extensive first-principles time-dependent calculations. The team's work yields new insights into the role of coupled-electron dynamics in these systems.

In metals, a part of the electrons is fully delocalized apart from their parent ions and these can freely move in solids. They are so-called free electrons and make metals conductive. In contrast to these free electrons, however, some other electrons are strongly localized on ions in transition metals. They are forced into certain areas, resulting in the electron density confinement and strong electron coupling that are key to various interesting phases of matter, such as high-Tc superconductivity, a charge density wave phase, and a metal-insulator transition (so-called Mott transition).

The challenge is to generate and even control such interesting phases of matter in ultrafast ways by using light to steer the electron localization. The only limitation would be the timescale of the thermalization where the controllability of electrons is disturbed by their environment.

Using ATAS, the researchers found an ultrafast modification of optical absorption in transition metals under an intense laser pulse at the attosecond timescale. They demonstrated that the transient absorption originates from ultrafast d-electron localization due to the pump pulse.The observed that transient absorption phenomena are robust against variation of experimental parameters, such as sample thickness, surface oxidation state and pump photon energy.

Furthermore, based on the state-of-the-art first-principles calculations, they unraveled that the ultrafast absorption change originates from the modification of electronic screening effects in the sub-nanometer scale through the attosecond electron-localization.

This work has revealed a novel possibility for the ultrafast manipulation of phases of matter on its natural timescale. Its results represent a major step forward in understanding light-induced electron dynamics in matter on the attosecond timescale. They provide the fundamental knowledge needed for the development of future optoelectronic devices, energy-efficient electronics, magnetic memory devices, spintronics and new types of solar cells.

Researchers have developed a soft neural implant that can be wirelessly controlled using a smartphone. It is the first wireless neural device capable of indefinitely delivering multiple drugs and multiple colour lights, which neuroscientists believe can speed up efforts to uncover brain diseases such as Parkinson's, Alzheimer's, addiction, depression, and pain.A team under Professor Jae-Woong Jeong from the School of Electrical Engineering at KAIST and his collaborators have invented a device that can control neural circuits using a tiny brain implant controlled by a smartphone. The device, using Lego-like replaceable drug cartridges and powerful, low-energy Bluetooth, can target specific neurons of interest using drugs and light for prolonged periods. This study was published in Nature Biomedical Engineering.

"This novel device is the fruit of advanced electronics design and powerful micro and nanoscale engineering," explained Professor Jeong. "We are interested in further developing this technology to make a brain implant for clinical applications."

This technology significantly overshadows the conventional methods used by neuroscientists, which usually involve rigid metal tubes and optical fibers to deliver drugs and light. Apart from limiting the subject's movement due to bulky equipment, their relatively rigid structure causes lesions in soft brain tissue over time, therefore making them not suitable for long-term implantation. Although some efforts have been made to partly mitigate adverse tissue response by incorporating soft probes and wireless platforms, the previous solutions were limited by their inability to deliver drugs for long periods of time as well as their bulky and complex control setups.

To achieve chronic wireless drug delivery, scientists had to solve the critical challenge of the exhaustion and evaporation of drugs. To combat this, the researchers invented a neural device with a replaceable drug cartridge, which could allow neuroscientists to study the same brain circuits for several months without worrying about running out of drugs.

These 'plug-n-play' drug cartridges were assembled into a brain implant for mice with a soft and ultrathin probe (with the thickness of a human hair), which consisted of microfluidic channels and tiny LEDs (smaller than a grain of salt), for unlimited drug doses and light delivery.

Controlled with an elegant and simple user interface on a smartphone, neuroscientists can easily trigger any specific combination or precise sequencing of light and drug delivery in any implanted target animal without the need to be physically inside the laboratory. Using these wireless neural devices, researchers can also easily setup fully automated animal studies where the behaviour of one animal could affect other animals by triggering light and/or drug delivery.

"The wireless neural device enables chronic chemical and optical neuromodulation that has never been achieved before," said lead author Raza Qazi, a researcher with KAIST and the University of Colorado Boulder.