The key to this unlikely marriage of wood and pests is a motif called the “Bouligand structure,” in which molecules stack up in a twisted shape, similar to tiny spiral staircases. Scientists have learned that the Bouligand structure provides a certain kind of resilience to cracking; the force of an impact is guided by those tiny, nanosized, staircase-like twists and turns through a series of detours. Rather than cracking straight through, the energy of a bump or crash is thus deflected through a kind of tortuous path, leaving the overall material intact and functional.

While wood does not have a natural Bouligand structure, it has attracted scientists for decades, in part because there is an ample supply of material left over after the processing of paper and commercial lumber.

“The idea of making useful products out of wood pulp has long intrigued a lot of people in many different industries,” says Jeff Gilman, who leads the composites project team at NIST.

By washing that pulp with acid to remove its lignin and amorphous cellulose, scientists discovered several years ago that they could create a milky solution that ultimately dried to form a new material with a Bouligand structure. The key component of this solution was tiny crystalline rods of cellulose, known as cellulose nanocrystals or nanocellulose. However, on their own, the pulp-derived Bouligand films are brittle and won’t hold much weight.

The NIST team hypothesized that combining the short wood-derived nanocellulose rods with another natural material with longer crystalline rods would result in something new that would be incredibly strong and flexible. With appropriate additives, this new material could be used to create films that could slow down the diffusion of water and oxygen.

“The right product, if developed, could be used in everything from aerospace composites to packaging that would keep food fresh,” Gilman said.

One option for the new composite material: the carcasses of a dried-up aquatic creature called a tunicate that is considered a pest in some countries and a delicious treat in others.

In many parts of Asia, the brown aquatic creatures (Styela clava) are often cooked and served in spicy sauces. But without natural predators present to eat them in new environments, their populations begin to grow into super-abundant numbers that eventually clog boat engines and fishing gear, outcompete native fish, reduce healthy plankton populations and foul and ruin productive shellfish beds. Some environmental managers think that finding a way to remove and use them as a resource could serve a beneficial purpose. Harvesting them is one option. Like an oyster, the inside of a tunicate is considered the tasty bit. The outside is usually just thrown away, meaning there could be a ready source for this material in areas where they are often cooked.

What specifically intrigued the NIST researchers, however, was the tunicate’s inner structure, which was made of very long, highly crystalline nanocellulose. These were different from the shorter crystals found in wood.

“Tunicates have stuck out as the gold standard for their physical properties,” said Johan Foster from Virginia Tech University, who is one of only a handful of teams working on tunicate harvest and research around the globe. Foster gathered and supplied the tunicates for the NIST project from a dock in Western France, where the animals are considered a nuisance species.

Some scientists had assumed that a composite made entirely out of long crystalline tunicate nanocellulose would be incredibly strong and tough. However, by testing dried mixed tunicate/wood composite materials, lead author Bharath Natarajan was able to identify the exact point of greatest toughness.

“If you put a little tunicate into the wood pulp composite, it makes it a little stiffer, and it doesn’t break as quickly and becomes more flexible,” Natarajan said. “Put in 10 percent and it’s twice as strong. If your mixture is 30 percent tunicate and 70 percent wood pulp, the resulting composite is 15-20 times tougher. But after that, you really don’t see an improvement in strength, and there is a reduction in toughness.”

Tunicates are plentiful, but remain expensive to process, so knowing exactly how much to add is key to scaling up their use in the future, and for keeping any resulting products affordable.

Adding the tunicates also caused the nanocrystals to twist in a different way and accelerated the structure formation in the wood pulp. It also formed a pattern that was tighter and denser, making the new composite material UV-reflective.

“Many materials begin to degrade if they are exposed to the sun for a long time,” said Gilman. “This material could potentially be used as a coating on other surfaces in order to reflect light and extend durability.”

In the coming years, Natarajan and his team will continue to test ways their new tunicate-wood pulp mixture could be used to manufacture resilient, flexible and UV-reflective composites for use in the manufacture of sustainable, lightweight automobiles and aerospace vehicles, among other products.

Now, new research from Caltech illustrates how a particular species of beneficial bacteria actually harnesses the body’s immune response so that it can settle down comfortably in the gut.

The work was done in the laboratory of Sarkis Mazmanian, Luis B. and Nelly Soux Professor of Microbiology and Heritage Medical Research Institute Investigator. A paper describing the research was published online on May 3 in the journal Science.

Led by graduate student Gregory Donaldson, researchers in the Mazmanian laboratory chose to examine a microbe called Bacterioides fragilis. The particular species is found abundantly in the large intestines of many mammals, including humans, and was previously shown by the Mazmanian lab to protect mice from certain inflammatory and neurological disorders such as inflammatory bowel disease and multiple sclerosis. Interestingly, though there are multiple strains of B. fragilis, healthy people form a long-term, monogamous relationship with only a single strain.

“Studies by other labs have shown that most people carry the same strain of B. fragilis throughout their lives,” says Donaldson. “We wanted to understand at a molecular level how these bacteria are able to colonize the gut in a stable, long-term way.”

First, the researchers aimed to examine B. fragilis‘s symbiotic relationship with the gut by physically looking at the locations where the bacteria reside. Using electron microscopy imaging on samples of mouse intestines, the team was able to see that B. fragilis clumps together in aggregates deep within the thick layer of mucus lining the gut, nestled close to the epithelial cells that line the surface of the intestine. Donaldson and his collaborators theorized that this spatial niche is necessary for a single species to settle in and establish a stable foothold.

The team next aimed to determine what mechanisms allow B. fragilis to colonize such a niche within the gut. They found that each B. fragilis bacterium is encased in a thick capsule made of carbohydrates. The capsule is typically associated with pathogens (bad bacteria) attempting to cloak themselves from recognition by and attack from the body’s immune system. Mutant bacteria lacking this capsule cannot aggregate and do not inhabit the mucosal layer. Thus, the researchers theorized that capsular carbohydrates are necessary for B. fragilis strains to monopolize their niche in the gut.

Because bacterial capsules were known to be related to an immune response in pathogenic bacteria, Donaldson and Mazmanian hypothesized that there may also be an immune response to the B. fragilis capsule. Indeed, they found that antibodies, immune proteins that grab onto and mark specific bacteria or viruses for other immune cells to engulf and destroy, were binding to the B. fragilis capsule in the intestine. One particular kind of antibody, immunoglobulin A or IgA, is found throughout the gut — in fact, it is the most abundantly produced type of antibody in humans — but its specific functions have been enigmatic.

Normally, an antibody response means imminent death to pathogenic bacteria. But curiously, IgA does not negatively affect most of the bacteria that normally live in the gut. In the case of B. fragilis, the researchers found, it actually helped the bacteria stick to epithelial cells. Furthermore, in mice that lacked IgA, the bacterium was less successful at colonizing the surface of the intestine and maintaining long-term stability.

The team believes that this IgA response to the B. fragilis capsule helps anchor the bacteria to the epithelial surface, thus providing an advantage.

“It is surprising to find that an immune response actually helps beneficial bacteria to thrive, which in turn helps the host thrive,” says Donaldson. “The study of immunology has mainly been in the context of pathogenic bacteria. But there are trillions of bacteria in the gut, and most of the time none of them are making you sick. Our study shows that there is active immune recognition of these bacteria, but it helps rather than hinders them. This suggests that the immune system is more than just a defense system and antibodies are more than just weapons.”

In future work, the researchers plan to study how the gut’s antibody response arises in the first place and why it helps B. fragilis while other antibodies hurt bacteria. Ultimately, this work could be used to improve colonization by other beneficial bacteria, as through the use of probiotics.

“Over the past decade, many studies have profiled the gut microbiome in a variety of diseases, lifestyles, geographies, and following birth,” says Mazmanian. “We’ve learned that the community composition of the microbiome correlates with particular conditions — for example, altered microbiome configurations may contribute to inflammatory bowel disease, autism, and Parkinson’s disease. What has remained largely unknown is how a microbiome is established and maintained in the first place. Our study reveals a molecular mechanism by which specific beneficial bacteria actively promote long-term intestinal colonization by engaging and co-opting the immune system, rather than trying to evade it as pathogens do. This discovery may lead to new ways to correct microbiome imbalances, and perhaps to prevent and treat a variety of human disorders.”

The Global Ecosystem Dynamics Investigation — or GEDI, pronounced like “Jedi,” of Star Wars fame — instrument is undergoing final integration and testing this spring and summer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The instrument is expected to launch aboard SpaceX’s 16th commercial resupply services mission, targeted for late 2018. GEDI is being led by the University of Maryland, College Park; the instrument is being built at NASA Goddard.

“Scientists have been planning for decades to get comprehensive information about the structure of forests from space to deepen our understanding of how this structure impacts carbon resources and biodiversity across large regions and even globally, as well as a host of other science issues,” said Ralph Dubayah, GEDI principal investigator and a professor of geographical sciences at the University of Maryland. “This is why seeing the instrument built and racing toward launch is so exciting.”

From its perch on the exterior of the orbiting laboratory, GEDI will be the first space-borne laser instrument to measure the structure of Earth’s tropical and temperate forests in high resolution and three dimensions. These measurements will help fill in critical gaps in scientists’ understanding of how much carbon is stored in the world’s forests, the potential for ecosystems to absorb rising concentrations of carbon dioxide in Earth’s atmosphere, and the impact of forest changes on biodiversity.

GEDI will accomplish its science goals through an ingenious use of light. The instrument is a lidar, which stands for light detection and ranging. It captures information by sending out laser pulses and then precisely measuring the light that is reflected back.

GEDI’s three lasers will produce eight ground tracks — two of the lasers will generate two ground tracks each, and the third will generate four. As the space station and GEDI orbit Earth, laser pulses will reflect off clouds, trees and the planet’s surface. While the instrument will gather height information about everything in its path, it is specifically designed to measure forests. The amount and intensity of the light that bounces back to GEDI’s telescope will reveal details about the height and density of trees and vegetation, and even the structure of leaves and branches within a forest’s canopy.

NASA has flown multiple Earth-observing lidars in space, notably the ICESat (Ice, Cloud and land Elevation Satellite) and CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) missions. But GEDI will be the first to provide high-resolution laser ranging of Earth’s forests.

“GEDI originally was scheduled to launch aboard a resupply mission in mid-2019, but the team at Goddard who is building and testing GEDI was always on track to deliver a finished instrument by the fall of this year,” said Project Manager Jim Pontius, making the move to an earlier resupply mission feasible. The team is now preparing to put GEDI through a battery of pre-launch tests to ensure it is ready to withstand the rigors of launch and operating in space.

NASA selected the proposal for GEDI in 2014 through the Earth Venture Instrument program, which is run by NASA’s Earth System Science Pathfinder (ESSP) office. ESSP oversees a portfolio of projects ranging from satellites, instruments on the space station, and suborbital field campaigns on Earth that are designed to be lower-cost and more focused in scope than larger, free-flying satellite missions.

Story Source:

Materials provided by NASA/Goddard Space Flight Center. Original written by Patrick Lynch. Note: Content may be edited for style and length.

One potential solution for this problem is a new switching element made from chromia (Cr₂O₃), which, one day, may be used in computer memory and flash drives. “The device has better potential for scaling, so it could be made smaller, and would use less energy once it’s suitably refined,” said Randall Victora, a researcher at the University of Minnesota and an author on the paper. The researchers report their findings in Applied Physics Letters, from AIP Publishing.

Computer memory is composed of switching elements, tiny devices that can switch on and off to store bits of information as ones and zeros. Previous researchers discovered that chromia’s magnetoelectric properties means it can be “switched” with only an electric field, but switching requires the presence of a static magnetic field. Building on these elements, Victora and Rizvi Ahmed have created a design for a memory device with a heart of chromia that does not require any externally applied magnetic field to operate.

Their design surrounds the chromia with magnetic material. This provides an effective magnetic field through quantum mechanical coupling to Cr magnetic moments, while allowing devices to be arranged in a way that blocks stray magnetic fields from affecting nearby devices. An element to read out the state of the device, to determine if it’s in one or zero state, is placed on top of the device. This could potentially pack more memory into a smaller space because the interface between the chromia and the magnet is the key to the coupling that makes the device function. As the device shrinks, the greater surface area of the interface relative to its volume improves the operation. This property is an advantage over conventional semiconductors, where increases in surface area as size shrinks lead to greater charge leakage and heat loss.

Next, Victora and Ahmed aim to collaborate with colleagues who work with chromia to build and test the device. If successfully fabricated, then the new device could potentially replace dynamic random access memory in computers.

“DRAM is a huge market. It provides the fast memory inside the computer, but the problem is that it leaks a lot of charge, which makes it very energy-inefficient,” Victora said. DRAM is also volatile, so information disappears once the power source is interrupted, like when a computer crash erases an unsaved document. This device, as described in the paper, would be nonvolatile.

However, such a memory device will likely take years to perfect. One significant barrier is the device’s heat tolerance. Computers generate a lot of heat, and modeling predicts that the device would stop functioning around 30 degrees Celsius, the equivalent of a hot summer day. Optimizing the chromia, perhaps by doping it with other elements, may improve its functioning and make it more suitable to replace existing memory devices.

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Materials provided by American Institute of Physics. Note: Content may be edited for style and length.

Physicians are less prone to prescribe opioid medication to patients with long-term pain — but they need more treatment options.

Clinicians and researchers at UW Medicine’s Center for Pain Relief found that an in-depth questionnaire can help immensely. Their work to create a pain assessment adaptable to any primary care clinic was recently published in the Journal of General Internal Medicine.

“PainTracker,” as they call it, is an assessment that can be filled out online from any digital device or completed on paper.

“To effectively treat the patient, these questions should be asked,” said lead author Dale Langford, research assistant professor in anesthesiology and pain medicine at the University of Washington School of Medicine.

She and co-authors estimated that 40 to 60 percent of patients with chronic pain have inadequate pain management.

“This lack of progress may partly be due to the multidimensionality of chronic pain, which is not routinely incorporated into it assessment and management,” they wrote.

The assessment addresses the patient’s treatment history, goals and expectations, pain intensity, pain-related disability, problems with pain medication, and quality-of-life issues such as sleep, depression and anxiety. A body diagram helps to pinpoint where the pain is affecting most.

Before each follow-up appointment, patients complete a subset of questions that yields a visual graph showing areas of improvement. The graphs also help providers show how improvement in sleep, function, and mood often occurs before reduction in pain.

“PainTracker provides a richer picture of patients’ responses to chronic pain treatments than the 0-10 pain rating scale,” said co-author Mark Sullivan, UW professor of psychiatry.

David Tauben, UW chief of the pain medicine and a co-author of the paper, said the tool has “dramatically transformed” his ability to properly assess, treat, and manage chronic pain.

He described the case of a patient new to his clinic who had already seen seven other doctors, including two pain specialists and had been prescribed a high dose of opioids and sedatives. The patient’s comments in PainTracker indicated severe depression, moderate anxiety, poor quality of life, sleep apnea, and likely post-traumatic stress disorder. At their first meeting, Tauben said, the patient embraced the responsibility to improve his mood, sleep and other ways to improve his life quality.

The patient found relief with sleep-hygiene training, and resilience training from the center’s clinical psychologist. Under the center’s direction, he sought out functional rehabilitation sessions from a physical therapist. He took yoga at a studio and mindfulness classes led by one of the center’s physicians.

A sample of primary-care providers (N=30) found an early version of PainTracker easy to use (70 percent) and thought that it helped patients to participate in their pain management (77 percent).

PainTracker is not currently used outside of the UW Center for Pain Relief, but it incorporated more than 12 tests, which are freely available and described in the article. They include the Alcohol Use Disorders Identification Test (AUDIT), fibromyalgia symptoms (FS), Generalized Anxiety Disorder 7-item scale (GAD-7), Opioid Risk Tool (ORT), Snoring, tiredness, observation of stopped breathing (STOP), high blood pressure, and widespread pain index (WPI).