Unusual Property in Hydrogen Fuel Device Discovered – Could Be Ultimate Guide to Self-Improvement

Hydrogen gas bubbles evolve from water at a thin layer of gallium oxynitride formed on gallium nitride surfaces. This work demonstrates the chemical transformation of gallium nitride into gallium oxynitride leads to sustained operation and enhanced catalytic activity, thus showing promise for oxynitride layers as protective catalytic coatings for hydrogen evolution. Credit: Illustration by Ella Maru Studios

Three years ago, scientists at the University of Michigan discovered an artificial photosynthesis device made of silicon and gallium nitride (Si/GaN) that harnesses sunlight into carbon-free hydrogen for fuel cells with twice the efficiency and stability of some previous technologies.

Now, scientists at Lawrence Livermore and Lawrence Berkeley national laboratories – in collaboration with the University of Michigan – have uncovered a surprising, self-improving property in Si/GaN that contributes to the material’s highly efficient and stable performance in converting light and water into carbon-free hydrogen. The research, reported in Nature Materials, could help radically accelerate the commercialization of artificial photosynthesis technologies and hydrogen fuel cells.  

Materials in solar fuels systems usually degrade, become less stable, and as a result produce hydrogen less efficiently, but the team found an unusual property in Si/GaN that somehow enables it to become more efficient and stable.

Previous artificial photosynthesis materials are either excellent light absorbers that lack durability or they are durable materials that lack light-absorption efficiency.

But silicon and gallium nitride are abundant and cheap materials that are widely used as semiconductors in everyday electronics such as LEDs (light-emitting diodes) and solar cells, said co-author Zetian Mi, a professor of electrical and computer engineering at the University of Michigan who invented Si/GaN artificial photosynthesis devices a decade ago.

When Mi’s Si/GaN device achieved a record-breaking 3 percent solar-to-hydrogen efficiency, he wondered how such ordinary materials could perform so extraordinarily well in an exotic artificial photosynthesis device – so he turned to senior author and Berkeley Lab scientist Francesca Toma for help.

HydroGEN: Taking a team science approach to solar fuels

Mi had learned about Toma’s expertise in advanced microscopy techniques for probing the nanoscale (billionths of a meter) properties of artificial photosynthesis materials through HydroGEN, supported by the DOE’s Hydrogen and Fuel Cell Technologies Office.

HydroGEN is a national lab consortium led by the National Renewable Energy Laboratory to facilitate collaborations between national labs, academia, and industry for the development of advanced water-splitting materials.  

Toma and lead author Guosong Zeng, a postdoctoral scholar in Berkeley Lab’s Chemical Sciences Division, suspected that GaN might be playing a role in the device’s unusual potential for hydrogen production efficiency and stability.

To find out, Zeng carried out a photoconductive atomic force microscopy experiment to test how GaN photocathodes could efficiently convert absorbed photons into electrons, and then recruit those free electrons to split water into hydrogen, before the material started to degrade and become less stable and efficient. 

They observed 2-3 orders of magnitude improvement in the material’s photocurrent coming from tiny facets along the “sidewall” of the GaN grain. The material also had increased its efficiency over time, even though the overall surface of the material didn’t change that much.

To gather more clues, the researchers recruited scanning transmission electron microscopy (STEM) at the National Center for Electron Microscopy in Berkeley Lab’s Molecular Foundry, and angle-dependent X-ray photon spectroscopy (XPS).  

Those experiments revealed that a 1 nanometer layer mixed with gallium, nitrogen, and oxygen – or gallium oxynitride – had formed along some of the sidewalls. A chemical reaction had taken place, adding “active catalytic sites for hydrogen production reactions,” Toma said.

Density functional theory (DFT) simulations, carried out by co-authors Tadashi Ogitsu and Anh Pham at LLNL confirmed their observations. “By calculating the change of distribution of chemical species at specific parts of the material’s surface, we successfully found a surface structure that correlates with the development of gallium oxynitride as a hydrogen evolution reaction site,” Ogitsu said. “We hope that our findings and approach – a tightly integrated theory-experiments collaboration enabled by the HydroGEN consortium – will be used to further improve the renewable hydrogen production technologies.” 

Looking ahead, Toma said that she and her team would like to test the Si/GaN photocathode in a water-splitting photoelectrochemical cell, and that Zeng will experiment with similar materials to get a better understanding of how nitrides contribute to stability in artificial photosynthesis devices – which is something they never thought would be possible.

“It was totally surprising,” Zeng said. “It didn’t make sense – but Pham’s DFT calculations gave us the explanation we needed to validate our observations. Our findings will help us design even better artificial photosynthesis devices.”

Reference: “Development of a photoelectrochemically self-improving Si/GaN photocathode for efficient and durable H₂ production” by Guosong Zeng, Tuan Anh Pham, Srinivas Vanka, Guiji Liu, Chengyu Song, Jason K. Cooper, Zetian Mi, Tadashi Ogitsu and Francesca M. Toma, 5 April 2021, Nature Materials.
DOI: 10.1038/s41563-021-00965-w

This work was supported by the HydroGEN Advanced Water Splitting Materials Consortium, established as part of the Energy Materials Network under DOE’s Office of Energy Efficiency and Renewable Energy.

Best Evidence to Date of How and When the Milky Way Came Together

Aging individual stars helped date an early merger event.

New research provides the best evidence to date into the timing of how our early Milky Way came together, including the merger with a key satellite galaxy.

Using relatively new methods in astronomy, the researchers were able to identify the most precise ages currently possible for a sample of about a hundred red giant stars in the galaxy.

With this and other data, the researchers were able to show what was happening when the Milky Way merged with an orbiting satellite galaxy, known as Gaia-Enceladus, about 10 billion years ago.

Their results were published on May 17, 2021, in the journal Nature Astronomy.

An artist’s impression of the thick disc in the middle of the Milky Way. Credit: ESO/NASA/JPL-Caltech/M. Kornmesser/R. Hurt, CC BY 4.0

“Our evidence suggests that when the merger occurred, the Milky Way had already formed a large population of its own stars,” said Fiorenzo Vincenzo, co-author of the study and a fellow in The Ohio State University’s Center for Cosmology and Astroparticle Physics.

Many of those “homemade” stars ended up in the thick disc in the middle of the galaxy, while most that were captured from Gaia-Enceladus are in the outer halo of the galaxy.

“The merging event with Gaia-Enceladus is thought to be one of the most important in the Milky Way’s history, shaping how we observe it today,” said Josefina Montalban, with the School of Physics and Astronomy at the University of Birmingham in the U.K., who led the project.

By calculating the age of the stars, the researchers were able to determine, for the first time, that the stars captured from Gaia-Enceladus have similar or slightly younger ages compared to the majority of stars that were born inside the Milky Way.

A violent merger between two galaxies can’t help but shake things up, Vincenzo said. Results showed that the merger changed the orbits of the stars already in the galaxy, making them more eccentric.

Vincenzo compared the stars’ movements to a dance, where the stars from the former Gaia-Enceladus move differently than those born within the Milky Way. The stars even “dress” differently, Vincenzo said, with stars from outside showing different chemical compositions from those born inside the Milky Way.

The researchers used several different approaches and data sources to conduct their study.

One way the researchers were able to get such precise ages of the stars was through the use of asteroseismology, a relatively new field that probes the internal structure of stars.

Asteroseismologists study oscillations in stars, which are sound waves that ripple through their interiors, said Mathieu Vrard, a postdoctoral research associate in Ohio State’s Department of Astronomy.

“That allows us to get very precise ages for the stars, which are important in determining the chronology of when events happened in the early Milky Way,” Vrard said.

The study also used a spectroscopic survey, called APOGEE, which provides the chemical composition of stars – another aid in determining their ages.

“We have shown the great potential of asteroseismology, in combination with spectroscopy, to age-date individual stars,” Montalban said.

This study is just the first step, according to the researchers.

“We now intend to apply this approach to larger samples of stars, and to include even more subtle features of the frequency spectra,” Vincenzo said.

“This will eventually lead to a much sharper view of the Milky Way’s assembly history and evolution, creating a timeline of how our galaxy developed.”

Reference: “Chronologically dating the early assembly of the Milky Way” by Josefina Montalbán, J. Ted Mackereth, Andrea Miglio, Fiorenzo Vincenzo, Cristina Chiappini, Gael Buldgen, Benoît Mosser, Arlette Noels, Richard Scuflaire, Mathieu Vrard, Emma Willett, Guy R. Davies, Oliver J. Hall, Martin Bo Nielsen, Saniya Khan, Ben M. Rendle, Walter E. van Rossem, Jason W. Ferguson and William J. Chaplin, 17 May 2021, Nature Astronomy.
DOI: 10.1038/s41550-021-01347-7

The work is the result of the collaborative Asterochronometry project, funded by the European Research Council.

Glaciologists Measure, Model Hard Glacier Beds – Develop “Slip Law” to Estimate Glacier Speeds

Researchers measure the topography of an exposed glacier bed at Castleguard Glacier in the Rocky Mountains of Alberta, Canada. Credit: Photo by Keith Williams, contributed by Christian Helanow

The field photos show the hard, rough country that some glaciers slide over: rocky domes and bumps in granite, rocky steps, and depressions in limestone. The glacier beds dwarf the researchers and their instruments. (As do the high mountains pictured on the various horizons.)

During their trips to glacier beds recently exposed by retreating glaciers in the Swiss Alps (Rhone, Schwarzburg and Tsanfleuron glaciers) and the Canadian Rockies (Castleguard Glacier), four glaciologists used laser and drone technology to precisely measure the rocky beds and record their very different contours.

The researchers turned the measurements into high-resolution digital models of those glacier beds. Then they went to work with manageable but representative subunits of the models to study how glaciers slide along the bedrock base.

“The simplest way to say it is we studied the relationship between the forces at the base of the glacier and how fast the glacier moves,” said Neal Iverson, a professor of geological and atmospheric sciences at Iowa State University and the study leader.

Small force changes, big speed changes

The resulting glacier “slip law” developed by the team describes that “relationship between forces exerted by ice and water on the bed and glacier speed,” Iverson said. And that slip law could be used by other researchers to better estimate how quickly ice sheets flow into oceans, drop their ice and raise sea levels.

In addition to Iverson, the study team included Christian Helanow, a postdoctoral research associate at Iowa State from 2018 to 2020 and currently a postdoctoral researcher in mathematics at Stockholm University in Sweden; Lucas Zoet, a postdoctoral research associate at Iowa State from 2012 to 2015 and currently an assistant professor of geoscience at the University of Wisconsin-Madison; and Jacob Woodard, a doctoral student in geophysics at Wisconsin.

The exposed bed of Schwarzburg Glacier in the Swiss Alps. Credit: Photo by Neal Iverson

A grant from the National Science Foundation supported the team’s work.

Helanow is the first author of a paper just published online by Science Advances that describes the new slip law for glaciers moving on bedrock.

Helanow’s calculations – based on a computer model of the physics of how ice slides over and separates locally from rough bedrock – and the resulting slip law indicate that small changes in force at the glacier bed can lead to big changes in glacier speed.

Measuring to inches

The researchers used two methods to collect high-resolution measurements of the topographies of recently exposed rock glacier beds. They used ground-based lidar mapping technology to take detailed 3D measurements. And, they sent up drones to photograph the beds from various angles, allowing detailed plotting of topography to a resolution of about 4 inches.

“We used actual glacial beds for this model, in their fully 3D, irregular forms,” Iverson said. “It turns out that is important.”

Previous efforts used idealized, 2D models of glacier beds. The researchers have learned such models are not adequate to derive the slip law for a hard bed.

“The main thing we’ve done,” Helanow said, “is use observed, rather than idealized, glacier beds to see how they impact glacier sliding.”

A universal slip law?

The work follows another slip law determined by Zoet and Iverson that was published in April 2020 by the journal Science.

There are a few key differences between the two: The first slip law accounts for the motion of ice moving over soft, deformable ground, while the second addresses glaciers moving over hard beds. (Both bed types are common beneath glaciers and ice sheets.) And, the first is backed by experimental data from a laboratory device that simulates slip at the bed of a glacier, rather than being based on field measurements of former glacier beds and computer modeling.

Even so, the two slip laws ended up having similar mathematical forms.

“They’re very similar – whether it’s a slip law for soft beds or hard beds,” Iverson said. “But it’s important to realize that the processes are different, the constants in the equations have quite different values for hard and soft beds.”

That has the researchers thinking ahead to more numerical analysis: “These results,” they wrote, “may point to a universal slip law that would simplify and improve estimations of glacier discharges to the oceans.”

Reference: “A slip law for hard-bedded glaciers derived from observed bed topography” by Christian Helanow, Neal R. Iverson, Jacob B. Woodard and Lucas K. Zoet, 14 May 2021, Science Advances.
DOI: 10.1126/sciadv.abe7798

Evolving Periodicity: Starlight, Star Bright…As Explained by Math

The evolving periodicity of the brightness of certain types of stars can now be described mathematically.

Not all stars shine brightly all the time. Some have a brightness that changes rhythmically due to cyclical phenomena like passing planets or the tug of other stars. Others show a slow change in this periodicity over time that can be difficult to discern or capture mathematically. KAUST’s Soumya Das and Marc Genton have now developed a method to bring this evolving periodicity within the framework of mathematically “cyclostationary” processes.

“It can be difficult to explain the variations of the brightness of variable stars unless they follow a regular pattern over time,” says Das. “In this study we created methods that can explain the evolution of the brightness of a variable star, even if it departs from strict periodicity or constant amplitude.”

Classic cyclostationary processes have an easily definable variation over time, like the sweep of a lighthouse beam or the annual variation in solar irradiance at a given location. Here, “stationary” refers to the constant nature of the periodicity over time and describes highly predictable processes like a rotating shaft or a lighthouse beam. However, when the period or amplitude changes slowly over many cycles, the mathematics for cyclostationary processes fails.

“We call such a process an evolving period and amplitude cyclostationary, or EPACS, process,” says Das. “Since EPACS processes are more flexible than cyclostationary processes, they can be used to model a wide variety of real-life scenarios.”

Das and Genton modeled the nonstationary period and amplitude by defining them as functions that vary over time. In doing this, they expanded the definition of a cyclostationary process to better describe the relationship among variables, such as the brightness and periodic cycle for a variable star. They then used an iterative approach to refine key parameters in order to fit the model to the observed process.

“We applied our method to model the light emitted from the variable star R Hydrae, which exhibited a slowing of its period from 420 to 380 days between 1900 and 1950,” says Das. “Our approach showed that R Hydrae has an evolving period and amplitude correlation structure that was not captured in previous work.”

Importantly, because this approach links EPACS processes back to classical cyclostationary theory, then fitting an EPACS process makes it possible to use existing methods for cyclostationary processes.

“Our method can also be applied to similar phenomena other than variable stars, such as climatology and environmetrics, and particularly for solar irradiance, which could be useful for predicting energy harvesting in Saudi Arabia,” Das says.

Reference: “Cyclostationary Processes With Evolving Periods and Amplitudes” by Soumya Das and Marc G. Genton, 4 February 2021, IEEE Transactions on Signal Processing.
DOI: 10.1109/TSP.2021.3057268

KiNET-X Experiment: NASA Launches Rocket in Search of Aurora Answers

NASA launched one of its largest sounding rockets Sunday from an East Coast facility in an experiment led by a University of Alaska Fairbanks Geophysical Institute space physics professor.

The four-stage Black Brant XII rocket carrying the KiNET-X experiment of principal investigator Peter Delamere lifted off from NASA’s Wallops Flight Facility in Virginia at 8:44 p.m. Eastern time. The ascent of the rocket, which flew on an arc into the ionosphere before beginning its planned descent over the Atlantic Ocean near Bermuda, could be seen along the East Coast.

The experiment seeks to understand how a large mass of plasma such as the solar wind interacts at the particle level with, for example, the plasma of Earth’s space environment.

The interaction between the solar wind and a planet’s magnetosphere appears as the aurora, whether here on Earth or on another planet that has a magnetic field and a substantial atmosphere. Physicists have long been trying to understand how the interaction works.

“KiNET-X was a fantastic success, as the Wallops and science teams worked through unprecedented pandemic-related challenges,” Delamere said. “Hats off to all involved. We couldn’t have asked for a better outcome tonight.”

The rocket released two canisters of barium thermite, which were then detonated — one at about 249 miles high and one 90 seconds later on the downward trajectory at about 186 miles, near Bermuda in the North Atlantic Ocean. The detonations produced purple and green clouds.

The barium, once dispersed from the canisters, turned into a plasma when it became ionized by the sunlight. The barium plasma clouds, which generated their own electromagnetic fields and waves, then interacted with the existing plasma of the ionosphere.

The experiment’s science team has already begun analyzing the data from that interaction.

The launch came on the final day of the 10-day launch window. Previous days had been plagued by bad weather at NASA’s Wallops Flight Facility and in Bermuda, unacceptably high winds at upper elevations, and an incident in which the rocket “came in contact with a launcher support during launch preparations,” according to NASA.

The experiment included three other Geophysical Institute space and plasma scientists: Project co-investigator Don Hampton, a Geophysical Institute research associate professor, was in Bermuda for ground observations; Geophysical Institute researchers Mark Conde, a space physics professor, and Antonius Otto, an emeritus professor of plasma physics, monitored the experiment from Fairbanks.

Two UAF students pursuing Ph.Ds at the Geophysical Institute also participated. Matthew Blandin supported optical operations at Wallops Flight Facility, and Kylee Branning was at Langley Air Research Center operating cameras on a NASA Gulfstream III monitoring the experiment.

The experiment also included researchers and equipment from Dartmouth University, University of New Hampshire, Clemson University, University of Maryland and NASA’s Goddard Space Flight Center.

Preparation began in 2018, when NASA approved the project.

Researchers Establish the First Entanglement-Based Quantum Network

Artist’s impression of the three-node quantum network. Credit: Matteo Pompili for QuTech

A team of researchers from QuTech in the Netherlands reports realization of the first multi-node quantum network, connecting three quantum processors. In addition, they achieved a proof-of-principle demonstration of key quantum network protocols. Their findings mark an important milestone towards the future quantum internet and have now been published in Science.

The quantum internet

The power of the Internet is that it allows any two computers on Earth to be connected with each other, enabling applications undreamt of at the time of its creation decades ago. Today, researchers in many labs around the world are working towards first versions of a quantum internet — a network that can connect any two quantum devices, such as quantum computers or sensors, over large distances. Whereas today’s Internet distributes information in bits (that can be either 0 or 1), a future quantum internet will make use of quantum bits that can be 0 and 1 at the same time. “A quantum internet will open up a range of novel applications, from unhackable communication and cloud computing with complete user privacy to high-precision time-keeping,” says Matteo Pompili, PhD student and a member of the research team. “And like with the Internet 40 years ago, there are probably many applications we cannot foresee right now.”

Researchers work on one of the quantum network nodes, where mirrors and filters guide the laser beams to the diamond chip. Credit: Marieke de Lorijn for QuTech

Towards ubiquitous connectivity

The first steps towards a quantum internet were taken in the past decade by linking two quantum devices that shared a direct physical link. However, being able to pass on quantum information through intermediate nodes (analogous to routers in the classical internet) is essential for creating a scalable quantum network. In addition, many promising quantum internet applications rely on entangled quantum bits, to be distributed between multiple nodes. Entanglement is a phenomenon observed at the quantum scale, fundamentally connecting particles at small and even at large distances. It provides quantum computers their enormous computational power and it is the fundamental resource for sharing quantum information over the future quantum internet. By realizing their quantum network in the lab, a team of researchers at QuTech — a collaboration between Delft University of Technology and TNO — is the first to have connected two quantum processors through an intermediate node and to have established shared entanglement between multiple stand-alone quantum processors.

An animation explaining the world’s first rudimentary quantum network. Credit: Slimplot for QuTech

Operating the quantum network

The rudimentary quantum network consists of three quantum nodes, at some distance within the same building. To make these nodes operate as a true network, the researchers had to invent a novel architecture that enables scaling beyond a single link. The middle node (called Bob) has a physical connection to both outer nodes (called Alice and Charlie), allowing entanglement links with each of these nodes to be established. Bob is equipped with an additional quantum bit that can be used as memory, allowing a previously generated quantum link to be stored while a new link is being established. After establishing the quantum links Alice-Bob and Bob-Charlie, a set of quantum operations at Bob converts these links into a quantum link Alice-Charlie. Alternatively, by performing a different set of quantum operations at Bob, entanglement between all three nodes is established.

Coauthors Matteo Pompili (left) and Sophie Hermans (right), both PhD student in the group of Ronald Hanson, at one of the quantum network nodes. Credit: Marieke de Lorijn for QuTech

Ready for subsequent use

An important feature of the network is that it announces the successful completion of these (intrinsically probabilistic) protocols with a “flag” signal. Such heralding is crucial for scalability, as in a future quantum internet many of such protocols will need to be concatenated. “Once established, we were able to preserve the resulting entangled states, protecting them from noise,” says Sophie Hermans, another member of the team. “It means that, in principle, we can use these states for quantum key distribution, a quantum computation or any other subsequent quantum protocol.”

Quantum Internet Demonstrator

This first entanglement-based quantum network provides the researchers with a unique testbed for developing and testing quantum internet hardware, software and protocols. “The future quantum internet will consist of countless quantum devices and intermediate nodes,” says Ronald Hanson, who led the research team. “Colleagues at QuTech are already looking into future compatibility with existing data infrastructures.” In due time, the current proof-of-principle approach will be tested outside the lab on existing telecom fiber — on QuTech’s Quantum Internet Demonstrator, of which the first metropolitan link is scheduled to be completed in 2022.

Higher-level layers

In the lab, the researchers will focus on adding more quantum bits to their three-node network and on adding higher level software and hardware layers. Pompili: “Once all the high-level control and interface layers for running the network have been developed, anybody will be able to write and run a network application without needing to understand how lasers and cryostats work. That is the end goal.”

Reference: “Realization of a multinode quantum network of remote solid-state qubits” by M. Pompili, S. L. N. Hermans, S. Baier, H. K. C. Beukers, P. C. Humphreys, R. N. Schouten, R. F. L. Vermeulen, M. J. Tiggelman, L. dos Santos Martins, B. Dirkse, S. Wehner and R. Hanson, 16 Apr 2021, Science.
DOI: 10.1126/science.abg1919

Global Study Finds Vast Under-Treatment of Diabetes

Only 1 in 10 people with diabetes in low- and middle-income countries is getting evidence-based, low-cost comprehensive care.

Nearly half a billion people on the planet have diabetes, but most of them aren’t getting the kind of care that could make their lives healthier, longer and more productive, according to a new global study of data from people with the condition.

Many don’t even know they have the condition.

Only 1 in 10 people with diabetes in the 55 low- and middle-income countries studied receive the type of comprehensive care that’s been proven to reduce diabetes-related problems, according to the new findings published in Lancet Healthy Longevity.

That comprehensive package of care — low-cost medicines to reduce blood sugar, blood pressure and cholesterol levels; and counseling on diet, exercise and weight — can help lower the health risks of under-treated diabetes. Those risks include future heart attacks, strokes, nerve damage, blindness, amputations and other disabling or fatal conditions.

The new study, led by physicians at the University of Michigan and Brigham and Women’s Hospital with a global team of partners, draws on data from standardized household studies, to allow for apples-to-apples comparisons between countries and regions.

The authors analyzed data from surveys, examinations and tests of more than 680,000 people between the ages of 25 and 64 worldwide conducted in recent years. More than 37,000 of them had diabetes; more than half of them hadn’t been formally diagnosed yet, but had a key biomarker of elevated blood sugar.

The researchers have provided their findings to the World Health Organization, which is developing efforts to scale up delivery of evidence-based diabetes care globally as part of an initiative known as the Global Diabetes Compact. The forms of diabetes-related care used in the study are all included in the 2020 WHO Package of Essential Noncommunicable Disease Interventions.

“Diabetes continues to explode everywhere, in every country, and 80% of people with it live in these low- and middle-income countries,” says David Flood, M.D., M.Sc., lead author and a National Clinician Scholar at the U-M Institute for Healthcare Policy and Innovation. “It confers a high risk of complications such as including heart attacks, blindness, and strokes. We can prevent these complications with comprehensive diabetes treatment, and we need to make sure people around the world can access treatment.”

Flood worked with senior author Jennifer Manne-Goehler, M.D., Sc.D., of Brigham and Women’s Hospital and the Medical Practice Evaluation Center at Massachusetts General Hospital, to lead the analysis of detailed global data.

Key findings

In addition to the main finding that 90% of the people with diabetes studied weren’t getting access to all six components of effective diabetes care, the study also finds major gaps in specific care.

For instance, while about half of all people with diabetes were taking a drug to lower their blood sugar, and 41% were taking a drug to lower their blood pressure, only 6.3% were receiving cholesterol-lowering medications.

These findings show the need to scale-up proven treatment not only to lower glucose but also to address cardiovascular disease risk factors, such as hypertension and high cholesterol, in people with diabetes.

Less than a third had access to counseling on diet and exercise, which can help guide people with diabetes to adopt habits that can control their health risks further.

Even when the authors focused on the people who had already received a formal diagnosis of diabetes, they found that 85% were taking a medicine to lower blood sugar, 57% were taking a blood pressure medication, but only 9% were taking something to control their cholesterol. Nearly 74% had received diet-related counseling, and just under 66% had received exercise and weight counseling.

Taken together, less than one in five people with previously diagnosed diabetes were getting the full package of evidence-based care.

Relationship to national income and personal characteristics

In general, the study finds that people were less likely to get evidence-based diabetes care the lower the average income of the country and region they lived in. That’s based on a model that the authors created using economic and demographic data about the countries that were included in the study.

The nations in the Oceania region of the Pacific had the highest prevalence of diabetes — both diagnosed and undiagnosed — but the lowest rates of diabetes-related care.

But there were exceptions where low-income countries had higher-than-expected rates of good diabetes care, says Flood, citing the example of Costa Rica. And in general, the Latin America and Caribbean region was second only to Oceania in diabetes prevalence, but had much higher levels of care.

Focusing on what countries with outsize achievements in diabetes care are doing well could provide valuable insights for improving care elsewhere, the authors say. That even includes informing care in high-income countries like the United States, which does not consistently deliver evidence-based care to people with diabetes.

The study also shines a light on the variation between countries and regions in the percentage of cases of diabetes that have been diagnosed. Improve reliable access to diabetes diagnostic technologies is important in leading more people to obtain preventive care and counseling.

Women, people with higher levels of education and higher personal wealth, and people who are older or had high body mass index were more likely to be receiving evidence-based diabetes care. Diabetes in people with “normal” BMI is not uncommon in low- and middle-income countries, suggesting more need to focus on these individuals, the authors say.

The fact that diabetes-related medications are available at very low cost, and that individuals can reduce their risk through lifestyle changes, mean that cost should not be a major barrier, says Flood. In fact, studies have shown the medications to be cost-effective, meaning that the cost of their early and consistent use is outweighed by the savings on other types of care later.

Reference: 21 May 2021, Lancet Healthy Longevity.
DOI: 10.1016/S2666-7568(21)00089-1

In addition to Flood, who is a clinical lecturer in hospital medicine at Michigan Medicine, U-M’s academic medical center, the study team includes two others from U-M: Michele Heisler, M.D., M.P.A., a professor of internal medicine and member of IHPI, and Matthew Dunn, a student at the U-M School of Public Health. The study was funded by the National Clinician Scholars Program at IHPI, and by the National Institute of Diabetes and Digestive and Kidney Diseases, Harvard Catalyst, and the National Center for Advancing Translational Sciences.

Boosting Energy Production at US Wind Plants With Wake Steering

U.S. wind plants achieve a predicted annual production gain of 0.8% by using wake steering.

Wake steering is a strategy employed at wind power plants involving misaligning upstream turbines with the wind direction to deflect wakes away from downstream turbines, which consequently increases the net production of wind power at a plant.

In Journal of Renewable and Sustainable Energy, by AIP Publishing, researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) illustrate how wake steering can increase energy production for a large sampling of commercial land-based U.S. wind power plants.

While some plants showed less potential for wake steering due to unfavorable meteorological conditions or turbine layout, several wind power plants were ideal candidates that could benefit greatly from wake steering control.

Overall, a predicted average annual production gain of 0.8% was found for the set of wind plants investigated. In addition, the researchers found that on wind plants using wake steering, wind turbines could be placed more closely together, increasing the amount of power produced in a given area by nearly 70% while maintaining the same cost of energy generation.

Illustration of wake steering for an example wind plant. Wind turbines are misaligned with the wind to redirect their wakes away from downstream turbines. Blue regions indicate lower wind speeds caused by wakes. Credit: Eric Simley, NREL

“We were surprised to see that that there was still a large amount of variability in the potential energy improvement from wake steering, even after accounting for the wake losses of different wind plants,” said author David Bensason.

Just as umbrellas may cast a shadow, wind turbines create a region of slower, more turbulent air flow downstream of their rotor, which is known as a wake. When these wakes flow into another turbine, they reduce its power production capacity.

The wake steering strategy “steers” these wakes away from turbines by offsetting the angle between the rotor face and the incoming wind direction. This technique sacrifices the power efficiencies of a few turbines in order to increase the performance of the wind power plant as a whole. Wake steering can only increase energy production if there are wake losses to start. Consequently, the benefits of wake steering tend to increase for wind plants with higher wake losses.

The study is one of the first to use the Gauss-Curl-Hybrid wake model, which NREL developed. This model predicts wake behavior in a wind plant more accurately than prior models and captures effects that are more prominent in large-scale plants. The researchers also combined several publicly available databases and tools that together make the investigation of wake steering potential for a large sample of U.S. wind plants possible.

“We hope that this study, which highlighted the potential for wake steering for a large sample of existing commercial wind plants in the U.S., motivates wind plant owners to implement wake steering in their wind plants to increase energy production and contribute to making wind energy a widely deployed affordable clean energy source,” said co-author Eric Simley.

Reference: “Evaluation of the potential for wake steering for U.S. land-based wind power plants” is authored by D. Bensason, E. Simley, O. Roberts, P. Fleming, M. Debnath, J. King, C. Bay and R. Mudafort, 18 May 2021, Journal of Renewable and Sustainable Energy.
DOI: 10.1063/5.0039325

New and Effective Treatment Discovered for Vitamin D Deficiency

Will aid patients with fat malabsorption issues including gastric bypass surgery, obese adults.

There are several million people worldwide with various fat malabsorption syndromes including those who have undergone gastric bypass surgery and those with obesity. These patients often have a difficult time absorbing vitamin D and both groups of patients are at an increased risk for vitamin D deficiency and therefore at higher risk for osteoporosis and osteomalacia (softening of the bones). Patients with obesity are also susceptible to vitamin D deficiency as vitamin D derived from intestinal absorption and cutaneous synthesis is diluted in a larger body pool of fat. Now a new study demonstrates 25-hydroxyvitamin D3 is an effective treatment for vitamin D deficiency for these specific patients.

According to the researchers, approximately one-third of adults are obese and require much larger doses of vitamin D to satisfy their requirement. “This vitamin D metabolite is better absorbed in patients with fat malabsorption syndromes and since it is not as fat-soluble, it does not gets diluted in the body fat and is effective in raising and maintaining blood levels of 25-hydroxyvitamin D in obese people,” explained corresponding author Michael F. Holick, PhD, MD, professor of medicine, physiology and biophysics and molecular medicine at Boston University School of Medicine.

Healthy adults, adults with a fat malabsorption syndrome, and obese adults were compared to evaluate if a more water-soluble form of vitamin D3 (25-hydroxyvitamin D3) was more effective than the same dose of vitamin D3 in improving their vitamin D status. The researchers observed that compared to healthy adults only about 36 percent of orally ingested vitamin D3 was found in the blood of patients with fat malabsorption syndromes including patients who had gastric bypass surgery. When the same adults ingested 25-hydroxyvitamin D3 the patients with fat malabsorption syndromes were able to absorb it as well as the healthy adults thereby raising their vitamin D status to the same degree. A similar observation was made in the obese subjects compared to the healthy controls. “Therefore using 25-hydroxyvitamin D3 could be a novel approach for treating vitamin D deficiency in patients with fat malabsorption syndromes and obese adults,” added Holick.

Vitamin D deficiency not only results in bone loss increasing risk for fracture but causes the painful bone disease osteomalacia. Patients who are vitamin D deficient with osteomalacia have unrelenting achiness in their bones and muscles. Vitamin D deficiency has been associated with an increased risk of many chronic illnesses including multiple sclerosis, type 1 diabetes, heart disease, type 2 diabetes, depression, neurocognitive dysfunction, and Alzheimer’s disease as well as infectious diseases including COVID.

Reference: “A pilot-randomized, double-blind crossover trial to evaluate the pharmacokinetics of orally administered 25-hydroxyvitamin D3 and vitamin D3 in healthy adults with differing BMI and in adults with intestinal malabsorption” by Nipith Charoenngam, Tyler A Kalajian, Arash Shirvani, Grace H Yoon, Suveer Desai, Ashley McCarthy, Caroline M Apovian and Michael F Holick, 19 May 2021, American Journal of Clinical Nutrition.
DOI: 10.1093/ajcn/nqab123

This trial was funded in part by a grant from Carbogen Amcis BV and institutional resources. NC received the institutional research training grant from the Ruth L Kirchstein National Research Service Award program from the National Institutes of Health (2 T32 DK 7201-42). CMA is supported by P30 DK046200. Carbogen Amcis BV, Netherlands, provided assistance and the supply of vitamin D3 and 25-hydroxyvitamin D3.

Invasive Alien Species Cost Africa’s Agricultural Sector a Staggering $3.6 Trillion a Year

Fall armyworm costs USD$9.4 bn a year in yield losses to African agriculture. Credit: CABI

CABI scientists have conducted the first comprehensive study on the economic impact of a range of Invasive Alien Species (IAS) on Africa’s agricultural sector, which they estimated to be USD $3.6 trillion a year.

This is equivalent to 1.5 times the Gross Domestic Product (GDP) of all African countries combined — or similar to that of Germany.

The average annual cost of IAS per country was USD $76.32 billion. Full details of the cost for individual countries are outlined in the paper published in the journal CABI Agriculture and Bioscience.

The team, comprising scientists from CABI centers in Africa and Europe, conducted a thorough literature review and online survey of 110 respondents — largely working in government or research — and established that Tuta (Phthorimaea) absoluta caused the highest annual yield losses at USD $11.45 billion, followed by the fall armyworm (Spodoptera frugiperda) at USD $9.4 billion.

The research took account of yield losses of major crops including maize, tomato, cassava, mango, and banana (USD $82.2 billion), as well as labor costs — through weeding (USD $3.63 trillion) — and loss of income derived from livestock (USD $173 million).

The annual impact of IAS — that also included Prostephanus truncatus, Bactrocera dorsalis, and Banana bunchy top virus (BBTV) — was highest on cassava (USD $21.8 billion), followed by citrus fruits (USD $14.6 billion), tomato (USD $10.1 billion), maize (USD $9.8 billion) and banana (USD $7.1 billion).

Lead author Dr. Rene Eschen said, “This study reveals the extent and scale of the economic impacts of Invasive Alien Species in the agricultural sector in one of the least studied continents.

“The results highlight the need for measures that prevent new species from arriving and established species from spreading, and that reduce management costs for widely present and impactful species through methods such as biocontrol. This will potentially reduce future production costs, lower yield losses and improve the livelihoods of farmers and other affected land users.”

Co-author, Dr. Bryony Taylor, said, “We have added to the knowledge base of the costs of Invasive Alien Species to Africa’s agricultural sector by including all countries within the continent where previous research only included a few.

“We also include the cost of reduced livestock-derived income and research and labor costs, which are generally not included in estimates of the costs of Invasive Alien Species.

“The results of this study provide policymakers with the evidence needed to enable prioritization of management measures for IAS, thereby reducing costs in the long term.”

Fernadis Makale, another co-author on the paper, said, “The large estimate for the weeding costs may come as a surprise but this work, often carried out by women and children, is never measured as part of the African economy.

“Moreover, it should not be concluded that people are being paid that amount as salaries. Rather, the estimate represents an opportunity cost, meaning that if people didn’t need to weed IAS could do something else, such as going to school or undertaking an income-generating economic activity.

“In addition, our study provides evidence of the need for country and regional quarantine and phytosanitary measures to prevent the entry and spread of new IAS, preventing additional, potentially huge costs as new IAS spread across the continent.”

The study comes after a policy summit on Invasive Species held in 2019, where 70 delegates, representing policymakers, research, the private sector and civil society from across Africa, resolved to develop a strategy and action plan to fight against Invasive Alien Species.

In response to the findings, Dr. Dennis Rangi, Director General, Development, CABI, said, “An estimated USD $3.6 trillion a year impact of Invasive Alien Species on Africa’s agricultural sector is a tremendous loss where over 80% of people living in rural areas rely on the crops they grow for food and income.

“The long-term effects are exacerbated by COVID-19 which continues to apply intense pressure on an already fragile agricultural sector and food supply chain. Notably, Governments across the continent put in place mitigation measures to manage the pandemic and its impact. Kenya for example proposed a USD $503 million economic stimulus package in 2020 to cushion its citizens.

“This is the same resolve, urgency, and investment our Governments need to channel towards managing the Invasive Alien Species problem.

“Under the African Union’s stewardship, countries now have a Strategy for Managing Invasive Species in Africa. The 2021-2030 strategy provides a framework for all relevant stakeholders at the Continental, Regional and National level can use to sustainably prevent and eradicate invasive species in Africa.”

H.E Ambassador Madam Josefa Sacko, Commissioner for Agriculture, Rural Development, Blue Economy and Sustainable Environment of the African Union Commission, said, “From this research, it is clear that Invasive Alien Species pose a devastating impact on Africa’s agricultural sector with a direct consequence on the achievement of the four commitments listed in the Malabo declaration. We cannot transform African agriculture if we do not pay special attention to the management and control of Invasive Alien Species. It’s time to act and walk the talk.

“The AU Commission (AUC) is providing a coordination mechanism for the implementation of the strategy for managing Invasive Alien Species at the continental level. This also includes providing strategic guidance, facilitating domestication and implementation of the strategy, plus seeking support from partners across the continent.

“Managing Invasive Alien Species is an absolute imperative if Africa’s agriculture is to meet its full potential and feed its growing population — which is expected to double to 2.5 bn people by 2050 — and contribute towards global food security,” added Madam Sacko.

Currently in its first year of implementation, the Invasive Alien Species strategy outlines six key areas of focus under its 2021-2025 action plan. One of the priority areas is the establishment in 2022 of continental, regional, and national emergency funding mechanisms for rapid action against Invasive Alien Species.

Reference: “Towards estimating the economic cost of invasive alien species to African crop and livestock production” by Rene; Eschen, Tim Beale, J. Miguel Bonnin, Kate L. Constantine, Solomon Duah, Elizabeth A. Finch, Fernadis Makale, Winnie Nunda, Adewale Ogunmodede, Corin F. Pratt, Emma Thompson, Frances Williams, Arne Witt, Bryony Taylor, 20 May 2021, CABI Agriculture and Bioscience.
DOI: 10.1186/s43170-021-00038-7

The research was financially supported by the Foreign, Commonwealth & Development Office (FCDO), UK, and the Directorate General for International Cooperation (DGIS), Netherlands, through CABI’s Action on Invasives program. CABI is an international intergovernmental organization, and we gratefully acknowledge the core financial support from our member countries (and lead agencies) including the United Kingdom (Foreign, Commonwealth & Development Office), China (Chinese Ministry of Agriculture and Rural Affairs), Australia (Australian Centre for International Agricultural Research), Canada (Agriculture and Agri-Food Canada), Netherlands (Directorate-General for International Cooperation), and Switzerland (Swiss Agency for Development and Cooperation).

Almost 1 Million Extra Deaths Related to COVID-19 Pandemic in 29 High Income Countries in 2020

Including 94,400 more deaths than expected in the UK alone.

Almost 1 million extra deaths relating to the covid-19 pandemic occurred in 29 high income countries in 2020, finds a study published by The BMJ today.

Except for Norway, Denmark and New Zealand, all other countries examined had more deaths than expected in 2020, particularly in men. The five countries with the highest absolute number of excess deaths were the US, UK, Italy, Spain, and Poland.

Measuring excess deaths — the number of deaths above that expected during a given time period — is a way of assessing the impact of the pandemic on deaths in different populations. However, previous studies have not accounted for temporal and seasonal trends and differences in age and sex across countries.

To address this, a team of international researchers, led by Dr. Nazrul Islam from the Nuffield Department of Population Health, University of Oxford, set out to estimate the direct and indirect effects of the covid-19 pandemic on mortality in 2020 in 29 high-income countries.

Using a mathematical model, they calculated weekly excess deaths in 2020 for each country, accounting for age and sex differences between countries, and also for seasonal and yearly trends in mortality over the five preceding years.

Overall an estimated 979,000 total excess deaths occurred in 2020 in the 29 countries analyzed. All countries experienced excess deaths in 2020, except New Zealand, Norway, and Denmark.

The five countries with the highest absolute number of excess deaths were the US (458,000), the UK (94,400), Italy (89,100), Spain (84,100), and Poland (60,100). New Zealand had lower overall deaths than expected (?2,500).

The total number of excess deaths was largely concentrated among people aged 75 or older, followed by people aged 65-74, while deaths in children under 15 were similar to expected levels in most countries and lower than expected in some countries.

In most countries, the estimated number of excess deaths exceeded the number of reported deaths from covid-19. For example, in both the US and the UK, estimated excess deaths were more than 30% higher than the number of reported covid-19 deaths.

However, other countries such as Israel and France had a higher number of reported covid-19 deaths than estimated excess deaths. The cause of this variation is unclear, but may result from access to testing and differences in how countries define and record covid-19 deaths.

In most countries, age-specific excess death rates were higher in men than in women, and the absolute difference in rates between the sexes tended to increase with age. However, in the US the excess death rate was higher among women than men in those aged 85 years or older.

The researchers point to some study limitations, including a lack of data from lower and middle income countries and on factors such as ethnicity and socioeconomic status, and they acknowledge that many indirect effects of a pandemic may need a longer timeframe to have a measurable effect on mortality.

Nevertheless, this was a large study using detailed age and sex-specific mortality data with robust analytical methods, and as such “adds important insights on the direct and indirect effects of the covid-19 pandemic on total mortality,” they say.

“Reliable and timely monitoring of excess deaths would help to inform public health policy in investigating the sources of excess mortality in populations and would help to detect important social inequalities in the impact of the pandemic to inform more targeted interventions,” they add.

Future work will also be needed to understand the impact of national vaccination programs on mortality in 2021, they conclude.

These findings confirm the huge toll of the covid-19 pandemic on mortality in high-income countries in 2020, say researchers at Imperial College London in a linked editorial.

But they warn that its full impact may not be apparent for many years, particularly in lower income countries where factors such as poverty, lack of vaccines, weak health systems, and high population density place people at increased risk from covid-19 and related harm.

And they point out that while mortality is a useful metric, policy informed by deaths alone overlooks what may become a huge burden of long-term morbidity resulting from covid-19.

“There is an urgent need to measure this excess morbidity, support those with long-term complications of covid-19, and fund health systems globally to address the backlog of work resulting from the pandemic,” they conclude.

References:

“Excess deaths associated with covid-19 pandemic in 2020: age and sex disaggregated time series analysis in 29 high income countries” 20 May 2021, The BMJ.
DOI: 10.1136/bmj.n1137

“Measuring the impact of covid-19” 20 May 2021, The BMJ.
DOI: 10.1136/bmj.n1239

National Border Walls and Fences Threaten Wildlife As Climate Changes

The USA-Mexico border wall could restrict the movement of jaguars as they shift between countries to find more hospitable places to live due to climate change. Credit: Stephen Willis/Durham University

Walls and fences designed to secure national borders could make it difficult for almost 700 mammal species to adapt to climate change, according to new research.

The study led by Durham University, UK, is the first to look at how man-made barriers could restrict the movement of animals as they shift between countries to find more hospitable places to live.

The researchers identified 32,000km of borders that are fortified with fences and walls, which have the potential to stop large numbers of animals from moving to more suitable environments.

Of these barriers, the USA-Mexico border wall, fences along the border between China and Russia, and fencing being constructed along the India-Myanmar border might be the most ecologically damaging, they said.

The USA-Mexico border wall alone could obstruct the movement of 122 mammal species displaced by climate change, the authors have calculated.

Border barriers, such as this along the USA-Mexico border, present an obstacle for many species whose ranges are shifting under climate change. Credit: Steve Hillebrand/USFWS

Mammals that could be obstructed by man-made borders across the world include leopards, tigers, the critically endangered Saiga antelope, cheetah, and jaguarundi (See Additional Information for more potentially affected species).

As well as considering political borders, the researchers also compared the likely impacts of ongoing climate change on species within countries.

They found that biodiversity loss is likely to be most severe in countries that are less responsible for the emissions that are driving climate change.

The findings are published in the journal Proceedings of the National Academy of Sciences, USA.

The researchers say that a third of mammals and birds will need to find suitable habitats in other countries by 2070 due to climate change, with this movement most likely to happen between the Amazon rainforest and tropical Andes, around the Himalayas, and in parts of Central and Eastern Africa.

They are calling for more cross-border conservation initiatives and habitat corridors to reduce the problem.

They have also urged world leaders to reduce the risk to biodiversity by committing to ambitious reductions in greenhouse gases when they meet at the UN Climate Change Conference in Glasgow this November.

Leopards are one of nearly 700 species that may be unable to move into new countries because of border barriers as the climate changes. Credit: Stephen Willis/Durham University

Joint-study lead Professor Stephen Willis, in Durham University’s Department of Biosciences, said: “Species all over the planet are on the move as they respond to a changing climate. Our findings show how important it is that species can move across national boundaries through connected habitats in order to cope with this change.

“Borders that are fortified with walls and fences pose a serious threat to any species that can’t get across them.

“If we’re serious about protecting nature, expanding transboundary conservation initiatives and reducing the impacts of border barriers on species will be really important – although there’s no substitute for tackling the greenhouse gas emissions at the root of the issue.”

In total the researchers looked at the effect of climate change on the movement of 12,700 mammal and bird species whose habitats could be affected by rising global temperatures, forcing them to find new homes.

They found that the loss of bird and mammal species was projected to be greater in poorer countries with lower CO2 emissions which would be impacted more significantly by global climate change.

Joint-study lead Mark Titley, a PhD researcher in Durham University’s Department of Biosciences, said: “The stark inequities between those who contributed most to climate change and those who will be most impacted raise really important questions of international justice.

“Fortunately, our models also show how strong and urgent emissions reductions, in line with the Paris Agreement, could greatly reduce the impacts on biodiversity and relieve the burden of such losses on less wealthy nations.

“World leaders must seize the opportunity at November’s COP 26 climate conference in Glasgow to ramp up ambitious pledges to cut emissions, or risk enormous harm to the natural world and our societies that depend on it.”

Reference: “Global inequities and political borders challenge nature conservation under climate change” by Mark A. Titley, Stuart H. M. Butchart, Victoria R. Jones, Mark J. Whittingham and Stephen G. Willis, 8 February 2021, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2011204118

The research was funded by the Natural Environment Research Council, part of UK Research and Innovation, and carried out in collaboration with BirdLife International.

Additional information

Species that could be affected by the USA-Mexico border wall:

• Mexican wolf
• Jaguar
• Jaguarundi
• White-lipped peccary
• Margay
• Common opossum
• Greater grison
• Southern spotted skunk

Species that could be affected by the India-Myanmar border:

• Sloth bear
• Indian pangolin
• Banteng
• Large spotted civet
• Himalayan goral
• Gongshan muntjac
• Indian grey mongoose
• Burmese hare

Species that could be affected by the China-Russia border:

• Tibetan antelope
• Chinese goral
• Goa
• Goitered gazelle
• Tibetan fox
• Desert hare
• Korean hare
• Hog badger

New Technology Makes Cancer Tumors Eliminate Themselves

A piece of the tumor was made completely transparent and scanned in 3D with a special microscope. The components labeled with fluorescent colors were rendered in a rotatable 3D representation on the computer (red: blood vessels, turquoise: tumor cells, yellow: therapeutic antibody). Credit: Plückthun Lab

A new technology developed by University of Zurich researchers enables the body to produce therapeutic agents on demand at the exact location where they are needed. The innovation could reduce the side effects of cancer therapy and may hold the solution to better delivery of Covid-related therapies directly to the lungs.

Scientists at the University of Zurich have modified a common respiratory virus, called adenovirus, to act like a Trojan horse to deliver genes for cancer therapeutics directly into tumor cells. Unlike chemotherapy or radiotherapy, this approach does no harm to normal healthy cells. Once inside tumor cells, the delivered genes serve as a blueprint for therapeutic antibodies, cytokines and other signaling substances, which are produced by the cancer cells themselves and act to eliminate tumors from the inside out.

Sneaking adenoviruses past the immune system undetected

“We trick the tumor into eliminating itself through the production of anti-cancer agents by its own cells,” says postdoctoral fellow Sheena Smith, who led the development of the delivery approach. Research group leader Andreas Plueckthun explains: “The therapeutic agents, such as therapeutic antibodies or signaling substances, mostly stay at the place in the body where they’re needed instead of spreading throughout the bloodstream where they can damage healthy organs and tissues.”

The UZH researchers call their technology SHREAD: for SHielded, REtargetted ADenovirus. It builds on key technologies previously engineered by the Plueckthun team, including to direct adenoviruses to specified parts of the body to hide them from the immune system.

High amount of drugs in the tumor, low concentration in other tissues

With the SHREAD system, the scientists made the tumor itself produce a clinically approved breast cancer antibody, called trastuzumab, in the mammary of a mouse. They found that, after a few days, SHREAD produced more of the antibody in the tumor than when the drug was injected directly. Moreover, the concentration in the bloodstream and in other tissues where side effects could occur were significantly lower with SHREAD. The scientists used a very sophisticated, high-resolution 3D imaging method and tissues rendered totally transparent to show how the therapeutic antibody, produced in the body, creates pores in blood vessels of the tumor and destroys tumor cells, and thus treats it from the inside.

Use to combat Covid-19 being investigated

Plueckthun, Smith and colleagues emphasize that SHREAD is applicable not only for the fight against breast cancer. As healthy tissues no longer come into contact with significant levels of the therapeutic agent, it is also applicable for delivery of a wide range of so-called biologics – powerful protein-based drugs that would otherwise be too toxic.

In fact, members of the Plueckthun group are currently applying their technology in a project aimed as a therapy for Covid-19. Adenoviral vectors are already being used in several of the COVID vaccines, including the Johnson & Johnson, AstraZeneca, China’s CanSino Biologics and Russia’s Sputnik V vaccines – but without the innovative SHREAD technology. “By delivering the SHREAD treatment to patients via an inhaled aerosol, our approach could allow targeted production of Covid antibody therapies in lung cells, where they are needed most,” Smith explains. “This would reduce costs, increase accessibility of Covid therapies and also improve vaccine delivery with the inhalation approach.”

Reference: “The SHREAD gene therapy platform for paracrine delivery improves tumor localization and intratumoral effects of a clinical antibody” by Sheena N. Smith, Rajib Schubert, Branko Simic, Dominik Brücher, Markus Schmid, Niels Kirk, Patrick C. Freitag, Viviana Gradinaru and Andreas Plückthun, 17 May 2021, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2017925118

Funding: Swiss National Science Foundation, NIH/National Cancer Institute

AI Uses Timing and Weather Data to Accurately Predict Cardiac Arrest Risk

Machine learning model combines timing and weather data.

A branch of artificial intelligence (AI), called machine learning, can accurately predict the risk of an out of hospital cardiac arrest — when the heart suddenly stops beating — using a combination of timing and weather data, finds research published online in the journal Heart.

Machine learning is the study of computer algorithms, and based on the idea that systems can learn from data and identify patterns to inform decisions with minimal intervention.

The risk of a cardiac arrest was highest on Sundays, Mondays, public holidays and when temperatures dropped sharply within or between days, the findings show.

This information could be used as an early warning system for citizens, to lower their risk and improve their chances of survival, and to improve the preparedness of emergency medical services, suggest the researchers.

Out of hospital cardiac arrest is common around the world, but is generally associated with low rates of survival. Risk is affected by prevailing weather conditions.

But meteorological data are extensive and complex, and machine learning has the potential to pick up associations not identified by conventional one-dimensional statistical approaches, say the Japanese researchers.

To explore this further, they assessed the capacity of machine learning to predict daily out-of-hospital cardiac arrest, using daily weather (temperature, relative humidity, rainfall, snowfall, cloud cover, wind speed, and atmospheric pressure readings) and timing (year, season, day of the week, hour of the day, and public holidays) data.

Of 1,299,784 cases occurring between 2005 and 2013, machine learning was applied to 525,374, using either weather or timing data, or both (training dataset).

The results were then compared with 135,678 cases occurring in 2014-15 to test the accuracy of the model for predicting the number of daily cardiac arrests in other years (testing dataset).

And to see how accurate the approach might be at the local level, the researchers carried out a ‘heatmap analysis,’ using another dataset drawn from the location of out-of-hospital cardiac arrests in Kobe city between January 2016 and December 2018.

The combination of weather and timing data most accurately predicted an out-of-hospital cardiac arrest in both the training and testing datasets.

It predicted that Sundays, Mondays, public holidays, winter, low temperatures, and sharp temperature drops within and between days were more strongly associated with cardiac arrest than either the weather or timing data alone.

The researchers acknowledge that they didn’t have detailed information on the location of cardiac arrests except in Kobe city, nor did they have any data on pre-existing medical conditions, both of which may have influenced the results.

But they suggest: “Our predictive model for daily incidence of [out of hospital cardiac arrest] is widely generalizable for the general population in developed countries, because this study had a large sample size and used comprehensive meteorological data.”

They add: “The methods developed in this study serve as an example of a new model for predictive analytics that could be applied to other clinical outcomes of interest related to life-threatening acute cardiovascular disease.”

And they conclude: “This predictive model may be useful for preventing [out of hospital cardiac arrest] and improving the prognosis of patients…via a warning system for citizens and [emergency medical services] on high-risk days in the future.”

In a linked editorial, Dr. David Foster Gaieski, of Sidney Kimmel Medical College at Thomas Jefferson University, agrees.

“Knowing what the weather will most likely be in the coming week can generate ‘cardiovascular emergency warnings’ for people at risk — notifying the elderly and others about upcoming periods of increased danger similar to how weather data are used to notify people of upcoming hazardous road conditions during winter storms,” he explains.

“These predictions can be used for resource deployment, scheduling, and planning so that emergency medical services systems, emergency department resuscitation resources, and cardiac catheterization laboratory staff are aware of, and prepared for, the number of expected [cases] during the coming days,” he adds.

References:

“Machine learning model for predicting out-of-hospital cardiac arrests using meteorological and chronological data” 17 May 2021, Heart.
DOI: 10.1136/heartjnl-2020-318726

“Next week’s weather forecast: cloudy, cold, with a chance of cardiac arrest” 17 May 2021, Heart.
DOI: 10.1136/heartjnl-2021-318950

Funding: Environmental Restoration and Conservation Agency of Japan; Japan Society for the Promotion of Science; Intramural Research Fund of Cardiovascular Disease of the National Cerebral and Cardiovascular Centre

Harvesting Light Like Nature Does: Synthesizing a New Class of Bio-Inspired, Light-Capturing Nanomaterials

POSS-peptoid molecules self-assemble into rhomboid-shaped nanocrystals. Credit: Illustration by Stephanie King | Pacific Northwest National Laboratory

Inspired by nature, researchers at Pacific Northwest National Laboratory (PNNL), along with collaborators from Washington State University, created a novel material capable of capturing light energy. This material provides a highly efficient artificial light-harvesting system with potential applications in photovoltaics and bioimaging.

The research provides a foundation for overcoming the difficult challenges involved in the creation of hierarchical functional organic-inorganic hybrid materials. Nature provides beautiful examples of hierarchically structured hybrid materials such as bones and teeth. These materials typically showcase a precise atomic arrangement that allows them to achieve many exceptional properties, such as increased strength and toughness.

PNNL materials scientist Chun-Long Chen, corresponding author of this study, and his collaborators created a new material that reflects the structural and functional complexity of natural hybrid materials. This material combines the programmability of a protein-like synthetic molecule with the complexity of a silicate-based nanocluster to create a new class of highly robust nanocrystals. They then programmed this 2D hybrid material to create a highly efficient artificial light-harvesting system.

“The sun is the most important energy source we have,” said Chen. “We wanted to see if we could program our hybrid nanocrystals to harvest light energy—much like natural plants and photosynthetic bacteria can—while achieving a high robustness and processibility seen in synthetic systems.” The results of this study were published May 14, 2021, in Science Advances. 

Materials scientist Chun-Long Chen finds inspiration for new materials in natural structures. Credit: Photo by Andrea Starr | Pacific Northwest National Laboratory

Big dreams, tiny crystals

Though these types of hierarchically structured materials are exceptionally difficult to create, Chen’s multidisciplinary team of scientists combined their expert knowledge to synthesize a sequence-defined molecule capable of forming such an arrangement. The researchers created an altered protein-like structure, called a peptoid, and attached a precise silicate-based cage-like structure (abbreviated POSS) to one end of it. They then found that, under the right conditions, they could induce these molecules to self-assemble into perfectly shaped crystals of 2D nanosheets. This created another layer of cell-membrane-like complexity similar to that seen in natural hierarchical structures while retaining the high stability and enhanced mechanical properties of the individual molecules.

“As a materials scientist, nature provides me with a lot of inspiration” said Chen. “Whenever I want to design a molecule to do something specific, such as act as a drug delivery vehicle, I can almost always find a natural example to model my designs after.”

POSS-peptoid nanocrystals form a highly efficient light-harvesting system that absorbs exciting light and emits a fluorescent signal. This system can be used for live cell imaging. Credit: Illustration by Chun-Long Chen and Yang Song | Pacific Northwest National Laboratory

Designing bio-inspired materials

Once the team successfully created these POSS-peptoid nanocrystals and demonstrated their unique properties including high programmability, they then set out to exploit these properties. They programmed the material to include special functional groups at specific locations and intermolecular distances. Because these nanocrystals combine the strength and stability of POSS with the variability of the peptoid building block, the programming possibilities were endless.

Once again looking to nature for inspiration, the scientists created a system that could capture light energy much in the way pigments found in plants do. They added pairs of special “donor” molecules and cage-like structures that could bind an “acceptor” molecule at precise locations within the nanocrystal. The donor molecules absorb light at a specific wavelength and transfer the light energy to the acceptor molecules. The acceptor molecules then emit light at a different wavelength. This newly created system displayed an energy transfer efficiency of over 96%, making it one of the most efficient aqueous light-harvesting systems of its kind reported thus far.

Demonstrating the uses of POSS-peptoids for light harvesting

To showcase the use of this system, the researchers then inserted the nanocrystals into live human cells as a biocompatible probe for live cell imaging. When light of a certain color shines on the cells and the acceptor molecules are present, the cells emit a light of a different color. When the acceptor molecules are absent, the color change is not observed. Though the team only demonstrated the usefulness of this system for live cell imaging so far, the enhanced properties and high programmability of this 2D hybrid material leads them to believe this is one of many applications.

“Though this research is still in its early stages, the unique structural features and high energy transfer of POSS-peptoid 2D nanocrystals have the potential to be applied to many different systems, from photovoltaics to photocatalysis,” said Chen. He and his colleagues will continue to explore avenues for application of this new hybrid material.

Reference: “Programmable two-dimensional nanocrystals assembled from POSS-containing peptoids as efficient artificial light-harvesting systems” by Mingming Wang, Yang Song, Shuai Zhang, Xin Zhang, Xiaoli Cai, Yuehe Lin, James J. De Yoreo and Chun-Long Chen, 14 May 2021, Science Advances.
DOI: 10.1126/sciadv.abg1448

Other authors of this study include: James De Yoreo, Mingming Wang, Shuai Zhang, and Xin Zhang from PNNL and Song Yang and Yuehe Lin from Washington State University. Shuai Zhang, James De Yoreo, and Chun-Long Chen are also affiliated with the University of Washington. This work was supported by the U.S. Department of Energy Basic Energy Sciences program as part of the Center for the Science of Synthesis Across Scales, an Energy Frontier Research Center located at the University of Washington.

Temperature-Dependent Sex Reversals in Bearded Dragon Embryos

Native to the arid landscapes of Australia, the central bearded dragon (Pogona vitticeps) is a fascinating species. It has genetic sex determination, but when incubated at high temperatures, genetic males sex reverse and develop as females. Credit: Whiteley SL et al., 2021, PLOS Genetics

Bearded dragon embryos become females either through sex chromosomes or hot temperatures.

Ancient cellular processes are likely involved in temperature-dependent sex reversals.

Bearded dragon embryos can use two different sets of genes to become a female lizard — one activated by the sex chromosomes and the other activated by high temperatures during development. Sarah Whiteley and Arthur Georges of the University of Canberra published these new findings on April 15th, 2021, in the journal PLOS Genetics.

In many reptiles and fish, the sex of a developing embryo depends on the temperature of the surrounding environment. This phenomenon, called temperature-dependent sex determination, was discovered in the 1960s, but the molecular details of how it happens have eluded scientists despite half a century of intensive research. Researchers investigated the biochemical pathways required to make a female in the new study by studying this phenomenon in bearded dragons. Male bearded dragons have ZZ sex chromosomes, while females have ZW sex chromosomes. However, hot temperatures can override ZZ sex chromosomes, causing a male lizard to develop as a female.

Whiteley and Georges compared which genes were turned on during development in bearded dragons with ZW chromosomes compared to ZZ animals exposed to high temperatures. They discovered that initially, different sets of developmental genes are active in the two types of females, but that ultimately the pathways converge to produce ovaries. The findings support recent research proposing that ancient signaling processes inside the cell help translate high temperatures into a sex reversal.

The new study is the first to show that there are two ways to produce an ovary in the bearded dragon and bringing us closer to understanding how temperature determines sex. The study also identifies several candidate genes potentially involved in temperature-dependent sex determination. These findings lay the foundation for future experiments to tease out each gene’s role in sensing temperature and directing sexual development.

Whiteley adds, “The most exciting component of this work is the discovery that the mechanism involves ubiquitous and highly conserved cellular processes, signaling pathways and epigenetic processes of chromatin modification. This new knowledge is bringing us closer to understanding how temperature determines sex, so it is a very exciting time to be in biology.”

Reference: “Two transcriptionally distinct pathways drive female development in a reptile with both genetic and temperature dependent sex determination” by Sarah L. Whiteley, Clare E. Holleley, Susan Wagner, James Blackburn, Ira W. Deveson, Jennifer A. Marshall Graves and Arthur Georges, 15 April 2021, PLOS Genetics.
DOI: 10.1371/journal.pgen.1009465

Funding: This work was supported by a Discovery Grant from the Australian Research Council (DP170101147) awarded to AG (lead), CEH and JMG. SLW was supported by a CSIRO Research Plus Postgraduate Award, Postgraduate-scholarships, and a Research Training Scholarship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.