Sunday, May 24, 2020

Low-severity fires enhance long-term carbon retention of peatlands

High-intensity fires can destroy peat bogs and cause them to emit huge amounts of their stored carbon into the atmosphere as greenhouse gases, but a new Duke University study finds low-severity fires spark the opposite outcome.

The smaller fires help protect the stored carbon and enhance the peatlands' long-term storage of it.

The flash heating of moist peat during less severe surface fires chemically alters the exterior of clumped soil particles and "essentially creates a crust that makes it difficult for microbes to reach the organic matter inside," said Neal Flanagan, visiting assistant professor at the Duke Wetland Center and Duke's Nicholas School of the Environment.

This reaction—which Flanagan calls "the crème brulee effect"—shields the fire-affected peat from decay. Over time, this protective barrier helps slow the rate at which a peatland's stored carbon is released back into the environment as climate-warming carbon dioxide and methane, even during periods of extreme drought.

By documenting this effect on peatland soils from Minnesota to Peru, "this study demonstrates the vital and nuanced, but still largely overlooked, role fire plays in preserving peat across a wide latitudinal gradient, from the hemi-boreal zone to the tropics," said Curtis J. Richardson, director of the Duke Wetland Center.

"This is the first time any study has been able to show that," Richardson said, "and it has important implications for the beneficial use of low-severity fire in managing peatlands, especially at a time of increasing wildfires and droughts."

The researchers published their peer-reviewed findings May 10 in the journal Global Change Biology.

Peatlands are wetlands that cover only 3% of Earth's land but store one-third of the planet's total soil carbon. Left undisturbed, they can lock away carbon in their organic soil for millennia due to natural antimicrobial compounds called phenolics and aromatics that earlier studies by the Duke team have shown can prevent even drier peat from decaying. If a smoldering, high-intensity fire or other major disturbance destroys this natural protection, however, they can quickly turn from carbon sinks to carbon sources.

To conduct the new study, Flanagan and his colleagues at the Duke Wetland Center monitored a U.S. Fish and Wildlife Service proscribed burn of a peatland pocosin, or shrub-covered wetland bog, at Pocosin Lakes National Wildlife Refuge in eastern North Carolina in 2015. Using field sensors, they measured the changing intensity of the fire over its duration and the effects it had on soil moisture, surface temperatures and plant cover. They also did chemical analyses of soil organic matter samples collected before and after the fire.

They then replicated the intensity and duration of the N.C. fire, which briefly reached temperatures of 850oF, in controlled laboratory tests on soil from peatlands in Minnesota, Florida and the Amazon basin of Peru, and analyzed the burn samples using using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.

The analysis showed that the low-severity fires increased the degree of carbon condensation and aromatization in the soil samples, particularly those collected from the peatlands' surface. In other words, the researchers saw the "crème brulee effect" in samples from each of the latitudes.

Long-term laboratory incubations of the burnt samples showed lower cumulative CO2 emissions coming from the peat for more than 1-3 years after the tests.

"Initially, there was some loss of carbon, but long-term you easily offset that because there's also reduced respiration by the microbes that promote decay, so the peat is decomposing at a much slower rate," Flanagan said.

Globally, peatlands contain approximately 560 gigatons of stored carbon. That's the same amount that is stored in all forests and nearly as much as the 597 gigatons found in the atmosphere.

"Improving the way we manage and preserve peatlands is critical given their importance in Earth's carbon budget and the way climate change is altering natural fire regimes worldwide," Richardson said, "This study reminds us that fire is not just a destructive anomaly in peatlands, it can also be a beneficial part of their ecology that has a positive influence on their carbon accretion."

Flanagan and Richardson conducted the study with fellow Duke Wetland Center researchers Hongjun Wang and Scott Winton. Winton also holds appointments at ETH Zurich's Institute of Biogeochemistry and Pollutant Dynamics and the Swiss Federal Institute of Aquatic Science and Technology.Natural mechanism could lower emissions from tropical peatlands

More information: Neal E. Flanagan et al, Low‐severity fire as a mechanism of organic matter protection in global peatlands: Thermal alteration slows decomposition, Global Change Biology (2020). DOI: 10.1111/gcb.15102

Journal information: Global Change Biology

Provided by Duke University

Genetic study suggests domestic goats got pathogen-resistant gene from wild relatives

IO PAN IO PAN PAN PAN

by Bob Yirka , Phys.org

Inner Mongolia cashmere goats are susceptible to gastrointestinal nematodes.
Credit: Yu Zhang, Northwest A&F University

An international team of researchers has found evidence that suggests wild relatives of domestic goats passed on a gene to their domesticated relatives that boosts their pathogen resistance. In their paper published in the journal Science Advances, the group describes their study of goat genetic history and what they learned from it.

As the researchers note, by providing a steady source of meat and milk, goat domestication played an important role in the advancement of agriculture, and from there, the development of civilizations. But they also note that it is still not clear what sort of genetic changes domestic goats may have undergone that allowed them to become such a successful domesticated animal. In this new effort, the researchers sought to learn more about such changes by studying the genes of both modern and ancient species.

The work involved analyzing the genes of 164 modern domestic goats, 24 modern wild goats, 52 ancient goats and four ancient wild goats from different parts of the world. As part of their analysis, they sequenced all the samples and also carried out a demographic analysis of each as a means of isolating genes that were passed between different species.

The researchers found that modern domestic goats got a lot of gene segments from wild mountain goats. And one gene in particular, from a West Caucasian tur-like species, appears to have given modern goats an immune boost. The gene transfer was calculated to have occurred approximately 7,200 years ago, and it helped domesticated goats ward off a pathogen that interferes with digestion. The wild goat was believed to have lived in a subtropical environment where it had adapted to the pathogens found there. The researchers report that almost every species of modern goat has the gene—it codes for a protein produced in the lining of the gut. Testing showed that the few modern species that do not have the gene are more susceptible to infestations of nematode worm eggs.

The researchers conclude by suggesting that successful domestication of goats appears to have more to do with genetic additions that warded off pathogens in crowded conditions than for increased milk productioniversity

Capra caucasica horn and skull morphology. Credit: Joséphine Lesur, Muséum National d’Histoire

Goat grazing helps control buckthorn growth
More information: Zhuqing Zheng et al. The origin of domestication genes in goats, Science Advances (2020). DOI: 10.1126/sciadv.aaz5216
Journal information: Science Advances

GOATS IN TREES MOROCCO

CHILE Atacama Desert minerals

Image: Sentinel-2A looks at Chile's salt flat

by European Space Agency MAY 22, 2020

Credit: contains modified Copernicus Sentinel data (2019), processed by ESA, CC BY-SA 3.0 IGO

The Copernicus Sentinel-2 mission takes us over part of Chile's Atacama Desert, which is bound on the west by the Pacific and on the east by the Andes. The Atacama is considered one of the driest places on Earth—there are some parts of the desert where rainfall has never been recorded.

In this image, captured on 26 June 2019, a specific area in the Tarapacá Region, in northern Chile, is featured—where some of the largest caliche deposits can be found. It is here where nitrates, lithium, potassium and iodine are mined.

Iodine, for example, is extracted in a process called heap leaching—which is widely used in modern large-scale mining operations. Leach piles are visible as rectangular shapes dotted around the image, although the exact reason for the different shades of colour is uncertain. Some leach piles could appear lighter or darker owing to the varying water content or soil type concentration.

The geometric shapes in the right are large evaporation ponds. Brine is pumped to the surface through a network of wells into the shallow ponds. The dry and windy climate enhances the evaporation of the water and leaves concentrated salts behind for the extraction of lithium—which is used in the manufacturing of batteries.

The bright, turquoise colours of the evaporation ponds are in stark contrast with the surrounding desert landscape—making them easily identifiable from space. Distinctive black lines visible in the image are roads that connect to the various construction sites.

Copernicus Sentinel-2 is a two-satellite mission to supply the coverage and data delivery needed for Europe's Copernicus programme. This false-colour image was processed by selecting spectral bands that can be used for classifying geological features.

Provided by European Space Agency

New method analyzes images to improve healthcare and manufacturing

by Miranda Buckheit, Pennsylvania State University

Patterns appear in both natural and human made systems, but they can be difficult for humans to recognize and analyze, especially in dynamic systems like the human heart or factory machines. To address this issue, researchers in the Penn State College of Engineering have developed a novel algorithm, which has implications for health care and manufacturing.

The researchers focused on understanding patterns in nonlinear, dynamic systems, as these intricate systems are challenging to analyze due to their nature—they fluctuate over multiple dimensions, such as space and time, and are near impossible to understand via human observation.

Led by Hui Yang, Harold and Inge Marcus Career Associate Professor, Soundar Kumara, Allen E. Pearce and Allen M. Pearce Professor of Industrial Engineering, and Cheng-Bang Chen, lecturer in the Harold and Inge Marcus Department of Industrial and Manufacturing Engineering, the methodology was published in the Chaos journal of the American Institute of Physics.

"Our methodology analyzes different kinds of recurrences in data to provide a better understanding of the world around us," Yang said. "This work allows us to build a bridge between biological patterns, like in human anatomy, and man-made patterns, like in manufacturing."

To create the novel algorithm, the team analyzed spatial data in complex, microscopic images produced by ultra-precision machining. UPM, a manufacturing process that uses single-crystal diamond tools to refine metal workpieces at the atomic scale, is widely used in modern industries such as semiconductors and aerospace to produce highly precise cuts or polishing.

The spatial data showed a variety of surfaces over the UPM images, ranging from flat to rough to severely rugged. Good, quality products should have a similar surface, and bad quality products might have different textures on the surface.

This operation captured and reiterated the behaviors of recurrence variations in the spatial data from the images to represent, characterize and quantify spatial patterns in the UPM images. The surface characteristics were shown to be highly correlated with the spatial recurrence patterns within the imaging data.

According to Chen, in the past, researchers had to physically measure a piece to get the quality of surface finishes when manufacturing. Their work now allows surface roughness to be approximated by using the images, which ultimately leads to cost savings and resource conservation.

In the future, this methodology can improve predictive models for the quality of UPM surface finishes to enhance the quality of manufacturing.

"The algorithm teaches you new things about the system as a whole," Kumara said. "Take for example: a signal impulse happens in one part of a system at a given time and space. Later, it has an observed repetition at a different point in time and space. If that pattern is found, then you can use it to predict such behaviors in the future."

According to Yang, the algorithm has broad implications for medical applications such as monitoring organ function, analyzing cancer images, and detecting organ dysfunction over time.

"You can use this algorithm on complex-structured data that is measurable or observable and is represented in 2-D, 3-D, or high-dimensional images," Yang said.

COVID-19: Researchers to model novel coronavirus for spread mitigation

More information: Hui Yang et al. Heterogeneous recurrence analysis of spatial data, Chaos: An Interdisciplinary Journal of Nonlinear Science (2020). DOI: 10.1063/1.5129959

Journal information: Chaos

Provided by Pennsylvania State University

Electrolysis: Chemists have discovered how to produce better electrodes

by Martin-Luther-Universität Halle-Wittenberg

Another step forward for renewable energies: The production of green hydrogen could be even more efficient in the future. By applying an unusual process step, chemists at Martin Luther University Halle-Wittenberg (MLU) have found a way to treat inexpensive electrode materials and considerably improve their properties during electrolysis. The group published their research results in the journal ACS Catalysis.

Hydrogen is thought to be the solution to the storage problem of renewable energies. It can be produced in local electrolysers, stored temporarily and then very efficiently converted back into electricity in a fuel cell. It also serves as an important raw material in the chemical industry. However, the green production of hydrogen is still hampered by the poor conversion of the supplied electricity. "One reason is that the dynamic load of the fluctuating electricity from the sun and wind quickly pushes the materials to their limits. Cheap catalyst materials rapidly become less active," says Professor Michael Bron from the Institute of Chemistry at MLU, explaining the basic problem.

His research group has now discovered a method that significantly increases both the stability and the activity of inexpensive nickel hydroxide electrodes. Nickel hydroxide is a cheap alternative to very active, but also expensive catalysts, like iridium and platinum. The scientific literature recommends heating the hydroxide up to 300 degrees. This increases the stability of the material and partially converts it to nickel oxide. Higher temperatures would completely destroy the hydroxide. "We wanted to see this with our own eyes and gradually heated the material in the laboratory to 1,000 degrees C," says Bron.

As temperatures increased, the researchers observed the expected changes to the individual particles under the electron microscope. These particles were converted to nickel oxide, grew together to form larger structures and, at very high temperatures, formed patterns reminiscent of zebra crossings. However, electrochemical testing surprisingly showed a constantly high activity level of the particles, which should have no longer been usable in the electrolysis. As a rule, large surfaces and, hence, smaller structures are more active during electrolysis. "We therefore attribute the high level of activity of our much larger particles to an effect that, surprisingly, only occurs at high temperatures: the formation of active oxide defects on the particles," says Bron.

Using X-ray crystallography, the researchers discovered how the crystal structure of the hydroxide particles changes as temperatures increase. They concluded that when heated to 900 degrees C, a point at which the particles exhibit the highest level of activity, the defects undergo a transitioning process that is completed at 1,000 degrees C. At this point, activity suddenly drops again.

Bron and his team are confident that they have found a promising approach since, even after repeated measurements after 6,000 cycles, the heated particles still generated 50% more electricity than the untreated particles. Next the researchers want to use X-ray diffraction to better understand why these defects increase the activity so much. They are also looking for ways to produce the new material so that smaller structures are retained even after heat treatment.

Advancing high temperature electrolysis: Splitting water to store energy as hydrogen

More information: Matthias Steimecke et al, Higher-Valent Nickel Oxides with Improved Oxygen Evolution Activity and Stability in Alkaline Media Prepared by High-Temperature Treatment of Ni(OH)2, ACS Catalysis (2020). DOI: 10.1021/acscatal.9b04788

Journal information: ACS Catalysis

Provided by Martin-Luther-Universität Halle-Wittenberg

Fill the beaker or glass with warm water. Carefully remove the erasers and metal sleeves so you can sharpen both ends of each pencil. These pencils are your electrodes. The graphite in them will conduct electricity, but won't dissolve into the water.

Electrolysis of Water Experiment - Splitting Water | HST

https://learning-center.homesciencetools.com › ... › Chemistry Projects

Double helix of masonry—Researchers discover the secret of Italian renaissance domes

by Princeton University

In a collaborative study in this month's issue of Engineering Structures, researchers at Princeton University and the University of Bergamo revealed the engineering techniques behind self-supporting masonry domes inherent to the Italian renaissance. Researchers analyzed how cupolas like the famous duomo, part of the Cathedral of Santa Maria del Fiore in Florence, were built as self-supporting, without the use of shoring or forms typically required.

Sigrid Adriaenssens, professor of civil and environmental engineering at Princeton, collaborated on the analysis with graduate student Vittorio Paris and Attilio Pizzigoni, professor engineering and applied sciences, both of the University of Bergamo. Their study is the first ever to quantitatively prove the physics at work in Italian renaissance domes and to explain the forces which allow such structures to have been built without formwork typically required, even for modern construction. Previously, there were only hypotheses in the field about how forces flowed through such edifices, and it was unknown how they were built without the use of temporary structures to hold them up during construction.

For Adriaenssens, the project advances two significant questions. "How can mankind construct such a large and beautiful structure without any formwork—mechanically, what's the innovation?" she asked. Secondly, "What can we learn?" Is there some "forgotten technology that we can use today?"

The detailed computer analysis accounts for the forces at work down to the individual brick, explaining how equilibrium is leveraged. The technique called discrete element modelling (DEM) analyzed the structure at several layers and stages of construction. A limit state analysis determined the overall equilibrium state, or stability, of the completed structure. Not only do these tests verify the mechanics of the structures, but they also make it possible to recreate the techniques for modern construction.

Applying their findings to modern construction, the researchers anticipate that this study could have practical applications for developing construction techniques deploying aerial drones and robots. Using these unmanned machines for construction would increase worker safety, as well as enhance construction speed and reduce building costs.

Another advantage of unearthing new building techniques from ancient sources is that it can yield environmental benefits. "The construction industry is one of the most wasteful ones, so that means if we don't change anything, there will be a lot more construction waste," said Adriaenssens, who is interested in using drone techniques for building very large span roofs that are self-supporting and require no shoring or formwork.

"Overall, this project speaks to an ancient narrative that tells of stones finding their equilibrium in the wonder of reason," said Pizzigoni, "from Brunelleschi's dome to the mechanical arms of modern-day robotics where technology is performative of spaces and its social use."Concrete printing in 3-D will put an end to boring buildings

More information: Vittorio Paris et al, Statics of self-balancing masonry domes constructed with a cross-herringbone spiraling pattern, Engineering Structures (2020). DOI: 10.1016/j.engstruct.2020.110440

Provided by Princeton University

Masonic architecture

Featured snippet from the web

Symbolism based on architecture and construction laid the basis of all Masonic iconography. The trowel, the bevel, the compass and Solomon's Shrine are among the most recognised symbols of Freemasonry and they refer to its roots – the medieval builders' guilds (architects, masons, sculptors).Sep 20, 2014

The True Face of Freemasonry | Article | Culture.pl

https://culture.pl › article › the-true-face-of-freemasonry

Bioinspired micro-robot based on white blood cells

by Max Planck Society

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny micro-robot that resembles a white blood cell traveling through the circulatory system. It has the shape, the size and the moving capabilities of leukocytes, and could perhaps revolutionize the minimally invasive treatment of illnesses.

Simulating a blood vessel in a laboratory setting, the team succeeded in magnetically steering the micro-roller through this dynamic and dense environment. The ball-shaped drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: Inside the body, there is no better access route to all tissues and organs than the circulatory system. It spans every cell, offering an ideal route for navigation. The research project was published in Science Robotics on 20 May with the title "Multifunctional surface micro-rollers for targeted drug delivery in physiological blood flow."

The team took inspiration from white blood cells, the task force of the immune system, as they are the only motile cells in the blood stream. On their patrol to places where pathogens have invaded, they roll along the blood vessel walls, penetrating out of the blood vessel when they reach a trouble spot. The key to their motility is mainly due to substantially decreased flow velocity at the vessel walls.

Exploiting the same phenomenon, the scientists developed a micro-robot they can actively propel forward and navigate inside the blood vessels in physiological high-speed blood flow conditions thanks to its magnetic properties. "Our vision was to create the next-generation vehicle for minimally invasive targeted drug delivery that can reach even deeper tissues inside the body with even more difficult access routes than what was previously possible," says Metin Sitti, Director of the Physical Intelligence Department at the MPI-IS and last author of the publication. Conventional therapies suffer from non-specific drug distribution in the body, he elaborates further, potentially causing severe side-effects in non-targeted organs and tissues.

Each micro-roller has a diameter of just under 8 micrometers and is made of glass microparticles. One side is covered with a thin nickel and gold film, the other with anti-cancer drug molecules and specific biomolecules that can recognize cancer cells. "Using magnetic fields, our micro-robots can navigate upstream through a simulated blood vessel, which is challenging due to the strong blood flow and dense cellular environment. None of the current micro-robots can withstand this stream. Additionally, our robots can autonomously recognize cells of interest such as cancer cells. They do this thanks to a coating of cell-specific antibodies on their surface. They can then release the drug molecules while on the move," Yunus Alapan explains. He is a postdoctoral researcher in the Physical Intelligence Department and the co-lead author of the publication.

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Video of microroller in static whole blood from mice. Credit: Alapan et al., Sci. Robot. 5, eaba5726 (2020)

In the laboratory setting, the micro-roller can reach a speed of up to 600 micrometers per second—around 76 body lengths per second, representing the fastest magnetic micro-robot at this size scale. However, several challenges need to be addressed before they can perform this motion in a real-life scenario. In fact, they are far from being tested in the human body. In the lab, the team was able to image the robots using microscopes and to steer them using electromagnetic coils.

https://techxplore.com/news/2020-05-bioinspired-micro-robot-based-white-blood.html
Video of the microrollers climbing towards the top of a curved 3D surface and propelling against blood flow. Credit: Alapan et al., Sci. Robot. 5, eaba5726 (2020)

"However, resolution of the current imaging modalities in a clinic are not high enough for imaging individual micro-robots inside the human body. Furthermore, therapeutic cargoes transported by a single micro-robot would not be sufficient, given the size difference between a micro-robot (around 10 micrometers) and the target tissues (thousands of micrometers). Therefore, the controlled manipulation of a high number of micro-robots in a swarm would be necessary to generate a sufficient effect. But we are still far from that," Ugur Bozuyuk says, who is a Ph.D. student in the same department and co-lead of the study. This was only the beginning.

https://techxplore.com/news/2020-05-bioinspired-micro-robot-based-white-blood.html

Video of active targeting of cancer cells by mobile microrollers. Microrollers with HER2 antibodies moved over the endothelial cells to attach to human breast cancer cells. Credit: Alapan et al., Sci. Robot. 5, eaba5726 (2020)

The motivation for the research project goes back to Nobel laureate Richard Feynman's famous talk "There is plenty of room at the bottom." In his talk, the physicist envisions mechanical devices at the micron scale that can move through blood vessels and perform the surgeries from within the human body, coining the term "swallowing the surgeon."

Over the past two decades, the research field has accelerated thanks to many leaps regarding fabrication techniques, materials used, actuation and imaging of the micro machines. However, current micro-robots inside the human body have been mostly limited to superficial tissues (e.g., inside the eye), locations with relatively easier access routes (e.g., the gastrointestinal tract), and stagnant or low-velocity fluidic environments. To reach deeper locations inside the body, there is perhaps no way around the circulatory system, despite the conditions being very harsh. The scientists hope the bio-inspired strategy they have developed will help create a new venue for controlled navigation of micro-robots in the circulatory system in high-speed blood flow conditions. This would potentially pave the way for targeted and localized therapeutic delivery by micro-robots.
Researchers use micro-robots to carry cells to a target site in live animals

More information: Yunus Alapan et al. Multifunctional surface microrollers for targeted cargo delivery in physiological blood flow, Science Robotics (2020). DOI: 10.1126/scirobotics.aba5726

Journal information: Science Robotics

Provided by Max Planck Society

Climate change helped produce San Diego's huge ocean heat wave in 2018, researchers find

by Gary Robbins

University of California, San Diego researchers have confirmed that climate change helped produce the historic 43-day ocean heat wave that drew big crowds to San Diego beaches during the summer of 2018.

The finding was published in the Journal of Geophysical Research-Oceans, in a paper that says the phenomenon could not be solely attributed to natural variations in the weather.

The average summer water temperature at the Scripps Pier in La Jolla is 70.7 degrees. But in 2018, ocean readings surpassed 73 degrees on every day of the heat wave, which lasted from July 19 to Aug. 30. And the temperature surpassed 75 on 30 of those days.

The heat wave peaked on Aug. 9 when the water temperature reached 79.5 degrees, the highest reading in the history of the pier, which opened in 1916.

UCSD's Scripps Institution of Oceanography says that coastal winds were unusually light that summer, which prevented cooler water from cycling to the surface. The marine layer also was weak, exposing the ocean to longer periods of sunlight. And monsoonal moisture flowed to the coast and helped the ocean hold its heat.

But UCSD says that the heat wave also was caused by global warming. Between 1916 and 2018 the baseline ocean temperature at the pier rose 2.2 degrees, Scripps says.

"Climate change is not only warming the atmosphere, it's warming the oceans," said Jimmy Fumo, a staff researcher at Scripps. "That's making marine heat waves more and more intense, and longer-lived. That's what we saw in 2018.

"The seemingly small bump in ocean temperatures can have massive impacts, and it doesn't just affect San Diego. It affects places all over the world."

Fumo was the lead author of UCSD's study of the heat wave.

Climate change is often cited as a factor in hurricanes, major rain events and heat waves. But scientists rarely take a deep look at how such change factors into a specific event, such as the warming that occurred in 2018.

The release of Fumo's paper coincided with a new period of unusually warm water along the San Diego County coastline. On May 4, the ocean hit 73 degrees at the pier, seven degrees above average.

At the time, the National Weather Service attributed the high temperatures to the absence of strong, seasonal winds along the coast. The winds have since picked up, and sea surface temperatures have returned to normal in many areas.

Weak winds in the Pacific drove record-breaking 2019 summertime marine heat wave

Distributed by Tribune Content Agency, LLC.

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