Tech

ITHACA, N.Y. - A Cornell University-led collaboration has created the first microscopic robots that incorporate semiconductor components, allowing them to be controlled - and made to walk - with standard electronic signals.

These robots, roughly the size of paramecium, provide a template for building even more complex versions that utilize silicon-based intelligence, can be mass produced, and may someday travel through human tissue and blood.

The collaboration is led by Itai Cohen, professor of physics, Paul McEuen, the John A. Newman Professor of Physical Science and their former postdoctoral researcher Marc Miskin, who is now an assistant professor at the University of Pennsylvania.

The team's paper, "Electronically Integrated, Mass-Manufactured, Microscopic Robots," published in Nature.

The walking robots are the latest iteration, and in many ways an evolution, of Cohen and McEuen's previous nanoscale creations, from microscopic sensors to graphene-based origami machines.

The new robots are about 5 microns thick (a micron is one-millionth of a meter), 40 microns wide and range from 40 to 70 microns in length. Each bot consists of a simple circuit made from silicon photovoltaics - which essentially functions as the torso and brain - and four electrochemical actuators that function as legs.

The researchers control the robots by flashing laser pulses at different photovoltaics, each of which charges up a separate set of legs. By toggling the laser back and forth between the front and back photovoltaics, the robot walks.

The robots are certainly high-tech, but they operate with low voltage (200 millivolts) and low power (10 nanowatts), and remain strong and robust for their size. Because they are made with standard lithographic processes, they can be fabricated in parallel: About 1 million bots fit on a 4-inch silicon wafer.

The researchers are exploring ways to soup up the robots with more complicated electronics and onboard computation - improvements that could one day result in swarms of microscopic robots crawling through and restructuring materials, or suturing blood vessels, or being dispatched en masse to probe large swaths of the human brain.

"Controlling a tiny robot is maybe as close as you can come to shrinking yourself down. I think machines like these are going to take us into all kinds of amazing worlds that are too small to see," said Miskin, the study's lead author.

"This research breakthrough provides exciting scientific opportunity for investigating new questions relevant to the physics of active matter and may ultimately lead to futuristic robotic materials," said Sam Stanton, program manager for the Army Research Office, an element of the Combat Capabilities Development Command's Army Research Laboratory, which supported the research.

Scientists led by Nanyang Technological University, Singapore (NTU Singapore) have developed a novel method of using fruit peel waste to extract and reuse precious metals from spent lithium-ion batteries in order to create new batteries.

The team demonstrated their concept using orange peel, which recovered precious metals from battery waste efficiently. They then made functional batteries from these recovered metals, creating minimal waste in the process.

The scientists say that their waste-to-resource approach tackles both food waste and electronics waste, supporting the development of a circular economy with zero waste, in which resources are kept in use for as long as possible. An estimated 1.3 billion tonnes of food waste and 50 million tonnes of e-waste are generated globally each year.

Spent batteries are conventionally treated with extreme heat (over 500°C) to smelt valuable metals, which emits hazardous toxic gases. Alternative approaches that use strong acid solutions or weaker acid solutions with hydrogen peroxide to extract the metals are being explored, but they still produce secondary pollutants that pose health and safety risks, or rely on hydrogen peroxide which is hazardous and unstable.

Professor Madhavi Srinivasan, co-director of the NTU Singapore-CEA Alliance for Research in Circular Economy (NTU SCARCE) lab, said: "Current industrial recycling processes of e-waste are energy-intensive and emit harmful pollutants and liquid waste, pointing to an urgent need for eco-friendly methods as the amount of e-waste grows. Our team has demonstrated that it is possible to do so with biodegradable substances.

"These findings build on our existing body of work at SCARCE under NTU's Energy Research Institute (ERI@N). The SCARCE lab was was set up to develop greener ways of recycling e-waste. It is also part of the NTU Smart Campus initiative, which aims to develop technologically advanced solutions for a sustainable future."

Assistant Professor Dalton Tay of the NTU School of Materials Science and Engineering and School of Biological Sciences said: "In Singapore, a resource-scarce country, this process of urban mining to extract valuable metals from all kinds of discarded electronics becomes very important. With this method, we not only tackle the problem of resource depletion by keeping these precious metals in use as much as possible, but also the problem of e-waste and food waste accumulation - both a growing global crisis."

The findings were published in the scientific journal Environmental Science & Technology in July.

A low-cost, sustainable approach

With industrial approaches to recycling battery waste generating harmful pollutants, hydrometallurgy - using water as a solvent for extraction - is increasingly being explored as a possible alternative. This process involves first shredding and crushing used batteries to form a crushed material called black mass. Researchers then extract valuable metals from black mass by dissolving it in a mix of strong acids or weak acids plus other chemicals like hydrogen peroxide under heat, before letting the metals precipitate.

While relatively more eco-friendly than conventional methods, the use of such strong chemicals on an industrial scale could generate a substantial amount of secondary pollutants, posing significant safety and health risks, said Asst Prof Tay.

The NTU team found that the combination of orange peel that has been oven-dried and ground into powder, and citric acid, a weak organic acid found in citrus fruits, can achieve the same goal.

In lab experiments, the team found that their approach successfully extracted around 90 per cent of cobalt, lithium, nickel, and manganese from spent lithium-ion batteries - a comparable efficacy to the approach using hydrogen peroxide.

Asst Prof Tay explained: "The key lies in the cellulose found in orange peel, which is converted into sugars under heat during the extraction process. These sugars enhance the recovery of metals from battery waste. Naturally-occurring antioxidants found in orange peel, such as flavonoids and phenolic acids, could have contributed to this enhancement as well."

Importantly, solid residues generated from this process were found to be non-toxic, suggesting that this method is environmentally sound, he added.

From the recovered materials, they then assembled new lithium-ion batteries, which showed a similar charge capacity to commercial ones. Further research is underway to optimise the charge-discharge cycling performance of these new batteries made from recovered materials.

This suggests that this new technology is "practically feasible for recycling spent lithium ion batteries in the industrial sense", said the researchers.

The team is now looking to further improve the performance of their batteries generated from treated battery waste. They are also optimising the conditions to scale up production and exploring the possibility of removing the use of acids in the process.

Prof Madhavi, who is also from NTU's School of Materials Science and Engineering and ERI@N, said: "This waste-to-resource approach could also potentially be extended to other types of cellulose-rich fruit and vegetable waste, as well as lithium-ion battery types such as lithium iron phosphate and lithium nickel manganese cobalt oxide. This would help to make great strides towards the new circular economy of e-waste, and power our lives in a greener and more sustainable manner."

A team at Tohoku University have perfected a new heat treatment technique with rapid heating and asymmetrical cooling processes in metallic glass. This technique enabled the team to induce a gradient of local glassy structure, bringing an apparent work hardening behavior.

Work hardening is the process by which a material is strengthened via plastic deformation and is not generally observed in metallic glasses due to their intrinsic random structure.

Although bulk metallic glasses (BMGs) have attracted much attention owing to their high strength, wide elastic limit and excellent thermoplasticity, a major disadvantage in terms of their mechanical properties has been a lack of ductility due to an intrinsic work softening at room temperature.

Dr Wookha Ryu, Assistant Professor Rui Yamada and Professor Junji Saida of the Frontier Research Institute for Interdisciplinary Sciences (FRIS) have now successfully produced unique Zr60Cu30Al10 bulk metallic glass with a 2D gradient rejuvenation state, which leads to an excellent ductility and tailored hardening of a monolithic BMG at room temperature.

"We have developed a novel structure controlling technique with asymmetric cryogenic heat treatment and produced a unique glassy structure with the 2D gradient rejuvenation state. The BMG exhibits a tailored hardening behavior throughout the overall plastic deformation stage as well as an excellent ductility at room temperature," said Professor Saida.

The local free volume concentration related to the rejuvenation state controls the shear band angle and the maximum effective shear stress. Hence, shear band propagation is prohibited and the formation of a complete shear plane transecting the whole specimen is blocked. The generation of plastic strain is accompanied by an increase in the critical shear stress, which results in a sustainable apparent hardening.

The team investigated a tailored hardening mechanism and established an experimental link between the gradient of the rejuvenation state and mechanical properties in Zr-based metallic glass.

NIMS and Tohoku Gakuin University have developed a boron-doped anisotropic Sm(Fe0.8Co0.2)12 thin film containing only small amount of rare earth elements. The compound exhibited 1.2 tesla coercivity, sufficient for use in automotive electric motors. This was achieved by creating a unique granular nanostructure in which Sm(Fe0.8Co0.2)12 grains are uniformly enveloped by an amorphous grain boundary phase approximately 3 nm in thickness. This compound exhibited superior magnetic properties to that of Nd-Fe-B based magnets even when processed into a thin film.

Demand for green technologies that can help to reduce CO2 emissions (e.g., electric motors for environmentally friendly vehicles and wind power generation) has been growing, leading to rapidly increasing demand for the high-performance permanent magnets needed for these technologies. The Nd-Fe-B based sintered magnets currently in use are composed not only of the rare earth element neodymium but also a heavy rare earth element: dysprosium. Because of the geopolitical risks associated with the acquisition of these materials, development of new magnets that do not rely on the scarce elements is desirable. Anisotropic SmFe12-based compounds containing relatively small quantities of rare earth elements have been studied for their potential to serve as an effective alternative candidate for the next generation permanent magnets. In 2017, NIMS confirmed that samarium-iron-cobalt compounds (Sm(Fe0.8Co0.2)12) are superior to neodymium magnets in terms of several important magnetic parameters: magnetization, magnetocrystalline anisotropy and Curie temperature. However, previous studies had found these compounds' coercivity--another important parameter for practical magnets--to be inadequate.

This research group focused on the fact that high-performance neodymium magnets with high coercivity have a multiphase microstructure in which Nd2Fe14B microcrystals are arranged in one direction and individually enveloped by an amorphous phase approximately 3 nm in thickness. The group then attempted to develop a similar microstructure in which individual Sm(Fe0.8Co0.2)12 grains are uniformly enclosed by a thin layer of an amorphous phase. In this research project, the group doped Sm(Fe0.8Co0.2)12 with boron, thereby fabricating a nano-granular microstructure in which Sm(Fe0.8Co0.2)12 nanoparticles are evenly surrounded by an amorphous phase approximately 3 nm in thickness. Moreover, this compound has an anisotropic granular microstructure, enabling it to exhibit a remnant magnetization greater than that exhibited by other SmFe12-based compounds with isotropic granular microstructures. As result, this compound exhibited a large coercivity of 1.2 T combined with a large remanent magnetization of 1.5 T, much larger than the previously developed SmFe12-based magnetic compounds.

This Sm(Fe0.8Co0.2)12 compound with an anisotropic, multiphase microstructure was proven to have very high coercivity, even when processed into a thin film. It may serve as a novel magnet capable of outperforming neodymium magnets. Previously studied anisotropic Sm(Fe0.8Co0.2)12 compounds exhibited significantly lower coercivity than the compound developed in this research. The underlying mechanisms which lead to realizing a high coercivity discovered in this research may be applicable to bulk magnets with the aim of developing practical anisotropic Sm(Fe0.8Co0.2)12 magnets with high coercivity.

Investigators from Brigham and Women's Hospital and the Massachusetts Institute of Technology are working on an innovative way of sustainably delivering drugs and influencing nutrient absorption in the gut. The gastrointestinal synthetic epithelial lining (GSEL) system is designed to coat the small intestine, an organ that plays a key role in drug and nutrient absorption. The team has demonstrated the GSEL system's ability to adhere to segments of the gastrointestinal tract from pigs and humans, and, in porcine models, has reported potential applications for the system in treating a variety of conditions, ranging from lactose intolerance to diabetes and obesity to tropical diseases such as schistosomiasis. Results of the team's proof-of-concept studies are published in Science Translational Medicine.

"The small intestine is an amazing organ -- it's the main site of drug and nutrient absorption and digestion and plays an important role as a barrier. We recognized its potential: If we could specifically target this location, it would open up new avenues for drug delivery and nutritional modulation," said corresponding author C. Giovanni Traverso, MB, BChir, PhD, a gastroenterologist and biomedical engineer in the Division of Gastroenterology at the Brigham. "The system we've developed has the potential to treat and manage a variety of diseases."

"We found that enzymes in the digestive tract can help synthesize polymers in the small intestine," said first author Junwei Li, who will become a research fellow at the Brigham this fall. "We anticipate broad adoption of this in-situ biomaterial generation idea for various applications."

The GSEL system combines two nature-inspired innovations. The first takes advantage of a chemical reaction triggered by catalase, an enzyme that helps break down hydrogen peroxide into oxygen in the small intestine. The second is a mussel-inspired tissue adhesive, similar to what mollusks use to attach themselves to rocks. Using these two concepts, Traverso, Li and colleagues designed a synthetic gut lining that can target the small intestine. Their goal is to develop a capsule, pill or gel that could be ingested, but for now, the team has tested administering the GSEL system endoscopically -- that is, directly inserting it into the small intestine.

To test the lining's therapeutic potential, the team looked at pig models for testing lactose intolerance, glucose absorption and the delivery of praziquantel, a drug for treating schistosomiasis. The team found evidence that the lining could deliver the drug in a sustained way, potentially reducing treatment to a once-a-day dose instead of three time a day. It also improved lactose digestion and regulated glucose absorption, indicating its potential for treating type 2 diabetes and preventing obesity.

In order to move from pig models into human trials, several hurdles remain, including further developing the GSEL system into an ingestible form. For now, Traverso, Li and colleagues are focused on continuing to evaluate safety in preclinical studies.

"For our studies, safety is a key focus of our work," said Traverso. "There are indications that this system can help patients suffering from many diseases, but before we can translate this technology for humans, we need to fully validate its safety and the effects of chronic use."

During experiments on high-performance Wire Arc Additive Manufacturing (WAAM) researchers from Peter the Great St.Petersburg Polytechnic University (SPbPU) produced a metal with unique ductility. The ductility is three times higher than specified in the standard. The research results were published in a prestigious journal - "Materials & Design".

Increase of WAAM productivity led to discovery of unique properties of aluminum. Elongation of specimens during tensile tests of produced metal increased from 12 to 41% compared to its standard properties for the same chemical composition. It means that material will be able to perform longer with the same loading conditions. The developed WAAM technology with higher process rates helps to achieve better material performance.

"In fact, this discovery can change the way of the components design, since now we are able to print high-scale metal object with triple loading capacity. Mechanical properties of metal are always considered with a margin, in our case this margin is several times higher than the specified in standard. This technology could be interesting for many industries, for example for Aerospace sector where we have a partner - S7 R&D Center. The manufactured material will be able to withstand deformations caused by load in Space for a longer time, " said Oleg Panchenko, Head of the Laboratory of Lightweight Materials and Structures SPbPU.

The solidification rate increase of metal has led to improvement in ductile properties of aluminum. It was achieved by increase of build rate up to 2.2 kg/h. Due to the lack of special equipment for 3D printing (WAAM) in the market initially the utilitarian goal of the research was to increase productivity.

In future, the researchers plan to increase solidification rate even more.

"This will help to trace dependence of material properties on additive manufacturing build rate. We have discovered a way to achieve unique properties and we are willing to move this border of knowledge further", says Oleg Panchenko.

The scientists also plan studying properties of the produced material under cyclic (fatigue) loading since the published study was based on the analysis performed for static loading. Researchers plan to test the hypothesis that materials with increased ductility show better fatigue performance.

Heavy metals suppress enzyme activity in the soil by 3-3.5 times and have especially prominent effect on the enzymes that support carbon and sulfur circulation. This was discovered by a soil scientist from RUDN together with his colleagues from Chile, Germany, the UK and Venezuela. The data obtained by the team can lead to more efficient use and fertilization of agricultural lands. The results of the study were published in the Science of the Total Environment journal.

Soil enzymes promote chemical reactions in soils, regulate cellular metabolism of soil organisms, participate in the decomposition of organic matter, and in the formation of humus. The quality and fertility of soil depend to a great extent on the activity of soil enzymes. Heavy metals, such as lead, zinc, cadmium, copper, and arsenic reduce the catalytic abilities of enzymes, thus interfering with the circulation of chemical elements.

Yakov Kuzyakov, a soil scientist from RUDN, together with his colleagues from Chile, Germany, UK and Venezuela analyzed 46 studies of the effect of heavy metals on soil enzymes. The authors of the work chose six enzymes and grouped them by the chemical elements they affected. For example, arylsulphatase is an enzyme that promotes reactions between water and sulfur-bearing acids. Therefore, it is associated with the biogeochemical cycle of sulfur. Similarly, other enzymes play their roles in the cycles of carbon, nitrogen, or phosphorus.

The team compared the activity of enzymes in healthy soils and ones contaminated with heavy metals. Intracellular enzymes (i.e. those found in the cells of plant roots and microbes) associated with carbon and sulfur cycles turned out to be the most sensitive to contamination. This might be due to the fact that extracellular enzymes bind with clays and organic matter which makes them more stable.

"Extracellular enzymes are more resistant due to the organo-mineral complex that stabilizes them in the soil environment and that intracellular enzymes lack. Enzymes that participate in nitrogen and phosphorus circulation showed medium to low activity reduction levels because they are predominantly extracellular," said Yakov Kuzyakov, a PhD in Biology, the Head of the Center for Mathematical Modeling and Design of Sustainable Ecosystems at RUDN.

Arylsulphatase and dehydrogenase, two enzymes in charge of gas exchange, glycolysis, and fermentation, were found the most sensitive. In soils contaminated with heavy metals, their activity reduced by 64% and 72% respectively, i.e. by 3-3.5 times. Some enzymes, such as beta-glucosidase and catalase, demonstrated reduced activity even when the concentration of heavy metals in the soil was very low (up to 200 mg per 1 kg). Unlike them, urease, an enzyme that plays a role in nitrogen circulation, is less sensitive to heavy metal concentration: its activity reduces by 10% at low levels of contamination and by up to 70% when contamination values are extremely high. Notably, the activity of acid phosphatases increases in the presence of small amounts of cadmium and copper in small amounts.

"Our study leads to a better understanding of the processes that cause soil systems to degrade under the influence of heavy metal contamination. The obtained results may help develop new methods of restoring contaminated soils," added Yakov Kuzyakov.

Astronauts aboard the International Space Station provided images of Hurricane Laura as it continues to strengthen in the Gulf of Mexico. Laura is pushing waters from the Gulf of Mexico that could inundate coastal areas miles inland and evacuations are in progress.

Watches and Warnings on Aug. 25

On Aug. 25, NOAA's National Hurricane Center (NHC) posted several watches and warnings on major Hurricane Laura.

A Storm Surge Warning is in effect for San Luis Pass, Texas to the mouth of the Mississippi River. A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. Some of the storm surge forecasts are extreme. From Sea Rim State Park to Intracoastal City, La. including Sabine Lake and Calcasieu Lake, a 10- to 15-foot storm surge is forecast. From Intracoastal City to Morgan City including Vermilion Bay an 8- to 12-foot storm surge is forecast. For additional areas and storm surges, visit: http://www.nhc.noaa.gov.

A Hurricane Warning is in effect from San Luis Pass, Texas to Intracoastal City, Louisiana.

A Tropical Storm Warning is in effect from Sargent, Texas to San Luis Pass and for areas east of Intracoastal City, Louisiana to the mouth of the Mississippi River.

A Storm Surge Watch is in effect for Freeport, Texas to San Luis Pass, Texas, from the mouth of the Mississippi River to Ocean Springs, Mississippi, and for Lake Pontchartrain, Lake Maurepas, and Lake Borgne.

A Hurricane Watch is in effect for from east of Intracoastal City to west of Morgan City, Louisiana.

International Space Station Finds a Large Hurricane

Astronaut Chris Cassidy aboard the International Space Station captured this photo of Hurricane Laura on Aug. 25, 2020 as it moved through the Gulf of Mexico and continued to strengthen. Laura is a large hurricane. On Aug. 26, hurricane-force winds extend outward up to 70 miles (110 km) from the center and tropical-storm- force winds extend outward up to 175 miles (280 km).

NASA Sees Laura from One Million Miles Away

NASA's EPIC Camera aboard NOAA's DSCOVR satellite in orbit one million miles from Earth, captured a full disk image of the Atlantic Ocean side of the globe. Hurricane Laura is seen moving through the Gulf of Mexico.

Laura's Status on Aug. 26, 2020 at 7 a.m. EDT

NOAA's National Hurricane Center (NHC) reported at 7 a.m. EDT, the eye of Hurricane Laura was located near latitude 26.4 degrees north and longitude 91.4 degrees west. The eye is about 280 miles (450 km) south-southeast of Lake Charles, Louisiana and about 290 miles (465 km) southeast of Galveston, Texas.

Laura is moving toward the northwest near 15 mph (24 kph) and this general motion should continue today, followed by a north-northwestward motion tonight.

Data from NOAA and Air Force Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 115 mph (185 kph) with higher gusts.  Laura is a dangerous category 3 hurricane on the Saffir-Simpson Hurricane Scale, and is forecast to continue strengthening into a category 4 hurricane later today. Buoy 42395, located just east of Laura's eye, recently reported a sustained wind of 74 mph (119 km/h) and a wind gust of 107 mph (172 km/h) and a wave height of 37 feet (11 meters).

The latest minimum central pressure estimated from NOAA and Air Force reconnaissance aircraft data is 963 millibars.

Laura's Forecast from NHC

The NHC warns that Laura may make landfall as a Category 4 hurricane and bring devastating effects. Heavy rain, dangerous storm surge, isolated tornadoes and hurricane-force sustained winds are expected. On the forecast track, Laura should approach the Upper Texas and southwest Louisiana coasts this evening and move inland near those areas tonight or Thursday morning.

NASA Researches Earth from Space

For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America's leadership in space and scientific exploration.

PITTSBURGH--Staying away from those with contagious infections, no matter how lonely it gets, may not only be common sense, but a natural instinct. But that doesn't mean humans or animals will automatically fall in line.

A study by Jessica Stephenson, head of Pitt's Stephenson Lab of Disease Ecology and Evolutionary Parasitology, examines the behaviors of guppies when introduced to an environment where they are placed near members of their species with infectious diseases. In the study an empty tank was flanked by one that contained a group of three guppies that represented potential contagion risk. Many guppies preferred the tank near other guppies, as expected from a social species. But some male guppies strongly avoided the side of the tank near the other fish and these distancing guppies were later shown to be highly susceptible to worm infections.

Stephenson and coauthors revisited these findings in light of COVID-19 in the article "Emerging Infectious Disease and the Challenges of Social Distancing in Human and Non-Human Animals," which published Aug. 12 in the Proceedings of the Royal Society of London, Series B.

Stephenson said human beings overall are "normal social animals in many of our behavioral response to infectious diseases" but benefits such as "global disease surveillance, rapid global communication and centralized governments with public health departments," may be wasted if we choose our social instincts over the evolutionary instinct that tells us to stay away from areas of potential infection.

"That the vast majority of our species has largely squandered the potential payoffs of these benefits is again consistent with other social animals: the cost of social distancing itself can outweigh the cost of contracting the disease," Stephenson said. "For some, no amount of Zoom and FaceTime can make up for the lost benefits of social interactions. These frustrating, if wholly natural, behavioral decisions will result in the persistence of COVID-19 until the advent of perhaps our greatest advantage over other species facing emerging infectious diseases: vaccination."

Washington, DC-- When a meteorite hurtles through the atmosphere and crashes to Earth, how does its violent impact alter the minerals found at the landing site? What can the short-lived chemical phases created by these extreme impacts teach scientists about the minerals existing at the high-temperature and pressure conditions found deep inside the planet?

New work led by Carnegie's Sally June Tracy examined the crystal structure of the silica mineral quartz under shock compression and is challenging longstanding assumptions about how this ubiquitous material behaves under such intense conditions. The results are published in Science Advances.

"Quartz is one of the most abundant minerals in Earth's crust, found in a multitude of different rock types," Tracy explained. "In the lab, we can mimic a meteorite impact and see what happens."

Tracy and her colleagues--Washington State University's (WSU) Stefan Turneaure and Princeton University's Thomas Duffy, a former Carnegie Fellow--used a specialized cannon-like gas gun to accelerate projectiles into quartz samples at extremely high speeds--several times faster than a bullet fired from a rifle. Special x-ray instruments were used to discern the crystal structure of the material that forms less than one-millionth of a second after impact. Experiments were carried out at the Dynamic Compression Sector (DCS), which is operated by WSU and located at the Advanced Photon Source, Argonne National Laboratory.

Quartz is made up of one silicon atom and two oxygen atoms arranged in a tetrahedral lattice structure. Because these elements are also common in the silicate-rich mantle of the Earth, discovering the changes quartz undergoes at high-pressure and -temperature conditions, like those found in the Earth's interior, could also reveal details about the planet's geologic history.

When a material is subjected to extreme pressures and temperatures, its internal atomic structure can be re-shaped, causing its properties to shift. For example, both graphite and diamond are made from carbon. But graphite, which forms at low pressure, is soft and opaque, and diamond, which forms at high pressure, is super-hard and transparent. The different arrangements of carbon atoms determine their structures and their properties, and that in turn affects how we engage with and use them.

Despite decades of research, there has been a long-standing debate in the scientific community about what form silica would take during an impact event, or under dynamic compression conditions such as those deployed by Tracy and her collaborators. Under shock loading, silica is often assumed to transform to a dense crystalline form known as stishovite--a structure believed to exist in the deep Earth. Others have argued that because of the fast timescale of the shock the material will instead adopt a dense, glassy structure.

Tracy and her team were able to demonstrate that counter to expectations, when subjected to a dynamic shock of greater than 300,000 times normal atmospheric pressure, quartz undergoes a transition to a novel disordered crystalline phase, whose structure is intermediate between fully crystalline stishovite and a fully disordered glass. However, the new structure cannot last once the burst of intense pressure has subsided.

"Dynamic compression experiments allowed us to put this longstanding debate to bed," Tracy concluded. "What's more, impact events are an important part of understanding planetary formation and evolution and continued investigations can reveal new information about these processes."

Current poultry food safety guidelines for Salmonella, the leading cause of foodborne illness outbreaks, are inadequate. A new study conducted by Thomas Oscar, USDA Agricultural Research Service, "Salmonella prevalence alone is not a good indicator of poultry food safety," published in Risk Analysis, explores additional factors that must be considered in order to identify poultry products that are truly safe for human consumption.

The poultry industry currently uses Salmonella prevalence or positivity rate as an indicator of food safety, but there are numerous other factors that influence the level of risk to public health. This study showed that even though other meats like ground chicken could have a lower Salmonella prevalence than ground turkey at meal preparation, they could pose a higher risk of salmonellosis if they are contaminated with higher numbers of more virulent serotypes of Salmonella.

The current approach to food safety in the poultry industry consists of two pillars:

Pathogen reduction and process control to reduce consumer exposure to these harmful pathogens;

Active surveillance to identify foodborne illness outbreaks with subsequent recalls of implicated foods.

These approaches are limited because pathogen prevalence is not the only risk factor for an outbreak and in the second pillar, harm to public health occurs before corrective action is taken.

Present food safety reviews do not include data such as Salmonella serotype and virulence and number, incidence and extent of temperature abuse, incidence and extent of undercooking, incidence and extent of cross-contamination during meal preparation, food consumption behavior, and host resistance which are important risk factors for salmonellosis from ground turkey and other poultry products.

Processing plants with a high prevalence of Salmonella on its poultry meat do not necessarily pose a higher risk of salmonellosis. Rather, poultry meat from a processing plant with a lower prevalence of Salmonella could pose a higher risk if:

A more virulent serotype(s) is(are) present;

The meat is shipped to a distribution channel with:

A higher incidence or extent of temperature abuse;

A higher incidence or extent of undercooking;

A higher incidence or extent of cross-contamination of ready-to-eat food;

A higher proportion of higher-risk food consumption behaviors;

A higher proportion of high-risk customers.

The study concludes that to increase food safety, a process risk model or computer model should be applied at the processing plant exit to integrate pathogen contamination data and post-processing risk factors to provide an objective description regarding the safety of individual lots of food before they are shipped to consumers. A more holistic approach to poultry food safety that considers Salmonella serotype, virulence, and number, and incidence and extent of temperature abuse, undercooking and cross-contamination, and food consumption behavior and host resistance is needed to better protect the public from foodborne pathogens like Salmonella.

Two different interventions both worked to significantly reduce the rate of inappropriate antibiotic prescriptions made by physicians in a telemedicine practice, a new study led by Children's National Hospital researchers shows. This finding, published Aug. 26 in the Journal of General Internal Medicine, could offer a new way to stem the growing problem of antibiotic resistance, particularly as telemedicine grows due to the ongoing COVID-19 pandemic.

According to the Centers for Disease Control and Prevention, more than 2.8 million antibiotic resistant infections occur in the U.S. each year. One way to help prevent this problem from growing is to prescribe antibiotics only when they're appropriate. Interventions meant to reduce unnecessary antibiotic prescribing have shown some success at brick-and-mortar medical practices. However, says Rana Hamdy, M.D., M.P.H., M.S.C.E., infectious diseases specialist and director of the Antimicrobial Stewardship Program at Children's National, these efforts have largely ignored direct-to-consumer telemedicine practices, even though they're one of the fastest growing health care sectors.

"Telemedicine has the potential for even more inappropriate antibiotic prescribing than brick-and-mortar facilities because doctors aren't physically examining patients and may not have the tools to accurately diagnose bacterial infections, such as looking in a patient's ears to diagnose an ear infection, or performing a throat swab to accurately diagnose strep throat," she says.

To test whether interventions that have reduced unnecessary antibiotic prescribing in brick-and-mortar facilities might also work for telemedicine practices, Dr. Hamdy and her colleagues worked with Doctor on Demand, a national direct-to-patient video visit medical practice providing primary and mental health care. Patients who use this service are connected online either "on demand" or at a scheduled appointment to an on-shift physician licensed in the state in which the patient is physically located. Each visit is documented in a proprietary electronic health record system.

The researchers focused on acute respiratory tract infections, a common reason for telemedicine visits and the most common diagnoses for antibiotic prescriptions in in-person medical facilities. They were specifically interested in four target conditions: bronchitis, sinusitis, pharyngitis and upper respiratory tract infections (a non-specific diagnosis that includes the common cold).

Dr. Hamdy and her team tracked the prescribing habits of 45 physicians within the practice for these common conditions for patients seen between Jan. 1, 2018 and Nov. 30, 2018. Midway through this period, in April 2018, the physicians were divided into two groups: One received education about appropriate antibiotic prescriptions through a one-hour slides presentation and a continuing medical education course. The other received this education plus feedback on the dashboard they saw when they logged onto their Doctor on Demand physician page. This feedback included their current antibiotic prescribing statistics compared to practice-wide statistics for the same condition.

The doctors provided more than 55,000 visits for patients diagnosed with any of the four target conditions during the study period. When the researchers compared antibiotic prescribing rates pre- and post-intervention, they saw decreases in both the education and education-plus-feedback groups. For bronchitis, a condition in which antibiotics should never be prescribed, antibiotic prescription rates fell from about 64% to 32% in the education-plus-feedback group and from about 47% to 35% in the education group. For sinusitis, a condition in which patients need to meet specific criteria to receive antibiotics, prescribing rates fell from about 87% to 77% in the education-plus-feedback and from 84% to 77% in the education group. For pharyngitis, a condition that requires a lab test not available through telemedicine for antibiotic prescribing, rates fell from 75% to 65% in the education-plus-feedback group and 81% to 75% in the education group. And for upper respiratory tract infections, another condition in which antibiotics aren't warranted, rates fell from 15% to 8% in the education-plus-feedback group and 18% to 13% in the education group.

Although education-plus-feedback appeared to be slightly more successful than education alone, Dr. Hamdy notes that either intervention significantly reduced inappropriate antibiotic prescriptions. These reductions were often minor; however, she adds, even small drops in the percentages of unnecessary prescribing rates can add up to millions of prescriptions per year - a boon to fighting antibiotic resistance.

Doctor on Demand considered these interventions so useful, Dr. Hamdy says, that they've continued to include antibiotic prescribing statistics on physicians' dashboards since the study ended.

"We hope these results elevate the importance of antibiotic stewardship for quality of care and that all direct-to-consumer companies rise to the occasion to implement effective antibiotic stewardship interventions in their practice," she says.

ITHACA, N.Y. - At the Berry Patch farm in Stephentown, New York, big, ripe blueberries are waiting to be picked.

The farm is experiencing one of its best seasons to date thanks to better management of fall infestations of spotted wing drosophila (SWD), part of a research collaboration with Greg Loeb, professor of entomology at Cornell AgriTech, part of Cornell University's College of Agriculture and Life Sciences.

For the past few years, Loeb has been experimenting with a thin mesh covering, called exclusion netting, around berry crops as a means to prevent SWD infestation. The efficacy of the netting, at Berry Patch and in Cornell AgriTech research fields, is documented in a paper, "Factors Affecting the Implementation of Exclusion Netting to Control Drosophila Suzukii on Primocane Raspberry," published in the journal Crop Protection.

The Berry Patch, owned by Dale-Ila Riggs and Don Miles, has experienced the devastation SWD can cause in late ripening berries like blueberries and raspberries. In 2012, their blueberry crop was attacked, resulting in a loss of 40% of their crop.

Unlike a regular fruit fly, which attacks overripe fruit, SWD attacks the berry as it's ripening in the field. Females lay eggs in the berries; the eggs then hatch into larvae during the berry ripening phase, rendering the fruit unmarketable.

"We were doing our best to keep SWD at bay back then," said Riggs, who co-authored the paper. "But we also knew spraying all the time wasn't sustainable and it also didn't align with our business model."

Riggs heard about positive preliminary results of the netting and reached out to Loeb. The netting attaches to a frame and surrounds berry crops in order to minimize SWD contact with berries.

While the research supports the viability of exclusion netting in managing SWD, it also indicates that additional management techniques may need to coincide with the netting. For example, SWD outbreak infestations could still occur when workers move in and out of netted plantings.

"For this reason, if growers adopt exclusion netting, they must be prepared to manage outbreaks as necessary," said lead author Dara Stockton, a postdoctoral associate in Loeb's lab. "Still, the benefits of using the netting seem to outweigh the risks and research indicates that as few as one to two sprays per year may be sufficient."

Over the six years that Riggs has been using exclusion netting for her blueberries, she said she has never had to apply pesticides and has had less than 1% incidence of SWD each year. Another major benefit is cost: Riggs said that for her .1-acre high-tunnel raspberry plot, she spent roughly $300 on exclusion netting, whereas it would cost her $600 for a season's worth of pesticides.

"Ultimately, the quality of the berries at our farm is most rewarding," she said. "Under these nettings, we are breaking records and giving Oregon and Washington blueberry yields a run for their money."

During the afternoon of Aug. 26, as major Hurricane Laura nears landfall near the Texas/Louisiana border, NASA satellites have been providing forecasters with a great deal of data on the storm, examining temperature, rainfall capability, storm structure and extent.

Infrared Data Reveals Powerful Rainmaking Capabilities

On Aug. 25 at 11:35 p.m. EDT (Aug. 26 at 0335 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite revealed the most powerful thunderstorms were around Laura's center where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center and were generating large amounts of rain. NASA research has determined that cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 52.7 degrees Celsius) has the capability to generate heavy rainfall.

NASA's Visible Image Of Cat 4 Hurricane Laura on Aug. 26

The MODIS instrument aboard NASA's Terra satellite provided a visible image of the large and powerful major Hurricane Laura in the Gulf of Mexico on Aug. 26, 2020 at 2:30 p.m. EDT. Laura's eye was clearly visible, the storm was well rounded, and the eye was surrounded by powerful thunderstorms.

Watches and Warnings on Aug. 25

On Aug. 25, NOAA's National Hurricane Center (NHC) posted several watches and warnings on major Hurricane Laura.

A Storm Surge Warning is in effect for San Luis Pass, Texas to the mouth of the Mississippi River. A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. Some of the storm surge forecasts are extreme. Johnson Bayou, LA to Rockefeller Wildlife Refuge including Calcasieu Lake is between 15 to 20 feet. Sea Rim State Park, TX to Johnson Bayou, LA including Sabine Lake is between 10 and 15 feet. Rockefeller Wildlife Refuge to Intracoastal City, LA between 10 and 15 feet. Intracoastal City, LA to Morgan City including Vermilion Bay between 8 to 12 feet.  For additional areas and storm surges, visit: http://www.nhc.noaa.gov.

A Hurricane Warning is in effect from San Luis Pass, Texas to Intracoastal City, Louisiana.

A Tropical Storm Warning is in effect from Sargent, Texas to San Luis Pass and for areas east of Intracoastal City, Louisiana to the mouth of the Mississippi River.

A Storm Surge Watch is in effect for Freeport, Texas to San Luis Pass, Texas, the mouth of the Mississippi River to Ocean Springs, Mississippi, and for Lake Pontchartrain, Lake Maurepas, and Lake Borgne.

A Hurricane Watch is in effect for from east of Intracoastal City to west of Morgan City, Louisiana.
Laura's Status on Aug. 26, 2020 at 2 p.m. EDT  

NOAA's National Hurricane Center (NHC) reported at 2 p.m. EDT (1800 UTC), the eye of Hurricane Laura was located near latitude 27.3 degrees north and longitude 92.5 degrees west. That is about 200 miles (20 km) south-southeast of Lake Charles, Louisiana.

Laura is moving toward the northwest near 16 mph (26 kph). A gradual turn toward the north-northwest and north is expected later today and tonight. Reports from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 140 mph (220 kph) with higher gusts.  Laura is an extremely dangerous category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Some additional strengthening is possible this afternoon, and Laura is forecast to remain a category 4 hurricane through landfall tonight.  Rapid weakening is expected after Laura makes over land.

Hurricane-force winds extend outward up to 70 miles (110 km) from the center and tropical-storm-force winds extend outward up to 175 miles (280 km). Tropical-storm-force winds have reached the coast of Louisiana and an observing site at Eugene Island recently measured sustained winds of 39 mph (63 kph) and a gust to 64 mph (104 kph).

The latest minimum central pressure estimated from reconnaissance aircraft data is 952 millibars.

Laura's Forecast from NHC

The NHC warns that Laura will likely make landfall as a Category 4 hurricane and bring devastating effects. Heavy rain, dangerous storm surge, isolated tornadoes and hurricane-force sustained winds are expected. On the forecast track, Laura will approach the Upper Texas and southwest Louisiana coasts this evening and move inland within that area tonight. The center of Laura is forecast to move over northwestern Louisiana tomorrow, across Arkansas Thursday night, and over the mid-Mississippi Valley on Friday.

NASA Researches Earth from Space

For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America's leadership in space and scientific exploration.

For updated and detailed forecasts, visit: http://www.nhc.noaa.gov

Turing machines were first proposed by British mathematician Alan Turing in 1936, and are a theoretical mathematical model of what it means for a system to "be a computer."

At a high level, these machines are similar to real-world modern computers because they have storage for digital data and programs (somewhat like a hard drive), a little central processing unit (CPU) to perform computations, and can read programs from their storage, run them, and produce outputs. Amazingly, Turing proposed his model before real-world electronic computers existed.

In a paper published in the American Physical Society's Physical Review Research, Santa Fe Institute researchers Artemy Kolchinsky and David Wolpert present their work exploring the thermodynamics of computation within the context of Turing machines.

"Our hunch was that the physics of Turing machines would show a lot of rich and novel structure because they have special properties that simpler models of computation lack, such as universality," says Kolchinsky.

Turing machines are widely believed to be universal, in the sense that any computation done by any system can also be done by a Turing machine.

The quest to find the cost of running a Turing machine began with Wolpert trying to use information theory -- the quantification, storage, and communication of information -- to formalize how complex a given operation of a computer is. While not restricting his attention to Turing machines per se, it was clear that any results he derived would have to apply to them as well.

During the process, Wolpert stumbled onto the field of stochastic thermodynamics. "I realized, very grudgingly, that I had to throw out the work I had done trying to reformulate nonequilibrium statistical physics, and instead adopt stochastic thermodynamics," he says. "Once I did that, I had the tools to address my original question by rephrasing it as: In terms of stochastic thermodynamics cost functions, what's the cost of running a Turing machine? In other words, I reformulated my question as a thermodynamics of computation calculation."

Thermodynamics of computation is a subfield of physics that explores what the fundamental laws of physics say about the relationship between energy and computation. It has important implications for the absolute minimum amount of energy required to perform computations.

Wolpert and Kolchinsky's work shows that relationships exist between energy and computation that can be stated in terms of algorithmic information (which defines information as compression length), rather than "Shannon information" (which defines information as reduction of uncertainty about the state of the computer).

Put another way: The energy required by a computation depends on how much more compressible the output of the computation is than the input. "To stretch a Shakespeare analogy, imagine a Turing machine reads-in the entire works of Shakespeare, and then outputs a single sonnet," explains Kolchinsky. "The output has a much shorter compression than the input. Any physical process that carries out that computation would, relatively speaking, require a lot of energy."

While important earlier work also proposed relationships between algorithmic information and energy, Wolpert and Kolchinsky derived these relationships using the formal tools of modern statistical physics. This allows them to analyze a broader range of scenarios and to be more precise about the conditions under which their results hold than was possible by earlier researchers.

"Our results point to new kinds of relationships between energy and computation," says Kolchinsky. "This broadens our understanding of the connection between contemporary physics and information, which is one of the most exciting research areas in physics."