Tech

Animals evolved from single-celled ancestors before diversifying into 30-40 distinct anatomical designs. When and how animal ancestors made the transition from single-celled microbes to complex multicellular organisms is unclear. But a new scientific study suggests animal-like embryological traits developed long before animals themselves.

The research - by an international research team led by scientists from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) and the University of Bristol - focused on ancient fossils of Caveasphaera, a multicellular organism found in 609-million-year-old rocks in South China's Guizhou Province that defies easy definition as animal or non-animal.

Using X-ray microscopy, the researchers analyzed the tiny fossils, which measure about a half-millimeter in diameter and were preserved down to their component cells. Various fossils displayed different stages of Caveasphaera development - from a single cell to a multicellular organism.

"We were able to sort the fossils into growth stages, reconstructing the embryology of Caveasphaera," said Kelly Vargas from the University of Bristol.

YIN Zongjun of NIGPAS interpreted the discovery: "Our results show that Caveasphaera sorted its cells during embryo development in just the same way as living animals, including humans." YIN emphasized, however, there is "no evidence that these embryos developed into more complex organisms."

Still, the discovery offers the earliest evidence of a key step in the evolution of animals - the capacity to develop distinct tissue layers and organs.

The verdict still seems to be out on whether Caveasphaera was itself an animal or just an important step in animal evolution, even as researchers search for more fossils. Co-author ZHU Maoyan of NIGPAS said, "Caveasphaera looks a lot like the embryos of some starfish and corals - we don't find the adult stages simply because they are harder to fossilize."

Whatever Caveasphaera turns out to be, its fossils tell us that animal-like embryonic development evolved long before the oldest definitive animals appeared in the fossil record.

Scientists from Far Eastern Federal University (FEFU), Far Eastern Branch of the Russian Academy of Sciences, Swinburne University of Technology, and Melbourne Center for Nanofabrication developed an ultrasensitive detector based on black silicon. The device is able to detect trace amounts of nitroaromatic compounds and can be applied to identify the majority of explosives or highly toxic pollutants for medical and forensic evaluations. The related article was published in ACS Sensors.

The novel sensor is based on the so-called "black silicon" that is fabricated by high-performing reactive etching of commercially available silicon substrates. Such etched silicon has a nanostructured spiky surface exhibiting unique optical properties. After etching, the surface is covered with a monolayer of carbazole molecules. This process is called chemical functionalization since the attached molecules impart the substrate a certain important function, namely, the ability to bind and concentrate nitroaromatic compounds on the surface. The carbazole monolayer renders the device sensitive to such widely spread nitroaromatic substances as nitrobenzene, o-nitrotoluene, 2.4-dinitrotoluene, etc. However, the sensor does not react to the presence of other molecules, such as benzene, toluene, tetrachloromethane, methanol, ethanol, and so on.

"Nitroaromatic compounds can be found in the waste waters of paint plants or military facilities and are extremely dangerous for the environment. Moreover, they are parts of many explosives as well. Their detection in trace concentrtion represents an important and complex practical task. Our sensor platform identifies the presence of nitroaromatic compounds by means of registering the changes in the luminescence spectrum of the functional layer of carbazole that selectively reacts to nitroaromatic molecules," said Alexander Kuchmizhak, a research associate at the VR and AR Center of the Science and Technology, FEFU.

According to the scientist, nanostructured black silicon used as the basis of the device gives it high sensitivity and an unprecedented dynamic measurement range. In the lab the sensor is able to provide information about the presence of toxic molecules in liquids or gases within several minutes.

"Combination of unique morphological and optical properties of black silicon being combined with easy-to-implement methods of surface chemistry used to functionalize silicon surface with carbazole molecules allowed to achieve unprecedented sensitivity. Our sensor is able to detect nitroaromatic compounds at concentrations down to ppt (part per trillion or 10-10 %). Extremely broad dynamic measurement range is caused by the unique spiky morphology of black silicon that provides uneven local concentration of carbazole molecules creating surface sites with different sensitivity," explained Alexander Mironenko, the designer of the sensor, and a senior research associate at the Institute of Chemistry, FEB RAS.

Scientists stated the manufacture of the new sensor platform is expected to be quite cheap compared to the existing analogs. Moreover, the same sensor can be used multiple times. It can become a part of gas sensor systems that secure public and ecological safety.

The participants of the work represented Far Eastern Federal University, Institute of Chemistry and the Institute of Automation and Management Processes of the Far Eastern Branch of the Russian Academy of Sciences, Swinburne University of Technology, and Melbourne Center for Nanofabrication.

Tufted puffins regulate their body temperature thanks to their large bills, an evolutionary trait that might explain their capacity to fly for long periods in search for food.

In a new study published in the Journal of Experimental Biology, researchers from McGill University and the University of California, Davis, used thermal imaging cameras to measure heat dissipation off the bodies and beaks of wild tufted puffins in the minutes after flying.

Their data showed that within 30 minutes of landing, the temperature of the puffin beaks dropped by 5°C (25°C - 20°C), while the heat radiating from their backs hardly changed. The beak "accounted for 10-18% of total heat exchange despite making up only 6%" of the bird's total surface area.

Big bills help cool birds as they fly

But why would puffins have evolved such a large bill? Kyle Elliott, a professor in McGill's Department of Natural Resource Sciences, thinks it could have to do with the energy they use when they fly.

Energetically speaking, flying is very taxing to birds. During flight, the thick-billed murre -which is closely related to the puffin - has an energy expenditure 31 times greater than when resting, the largest ever measured in vertebrates. This produces significant amounts of heat, says Elliott, the study's senior author, suggesting that some birds evolved a large bill to help them cool down when they fly.

"The avian bill is a classic example of how evolution shapes morphology," Elliott said.

To illustrate, Hannes Schraft, the study's lead author and formerly a doctoral student in the Biology Department at the University of California, explained that "thick-billed murres (and presumably puffins) produce about as much heat as a light bulb when they are flying."

"Our results support the idea that body heat regulation has played a role in shaping some bird beaks. We think this also an example of exaptation, which means that an external structure is amplified to serve a new function; much in the same way the desert hare's ears became bigger to help them cool down," Elliott adds.

A way of dumping extra body heat

"We tried to figure out whether puffins use their impressively large beaks to dump extra body heat when they fly," says Schraft, who is now a postdoctoral fellow at Université du Québec à Montréal.

"We thought this might be the case because previous research has shown this to be the case in toucans and hornbills, bird species who also have very large bills."

Because of its feathers, a bird's body is very well insulated so thermoregulation can't happen through sweating. Instead, the bill serves as a radiator when it needs to cool down - the equivalent of humans sweating on a hot summer day.

Schraft admits that this can seem counter intuitive. After all, when birds get cold, we often see them hide their beak in their feathers to stay warm. Furthermore, biologists have demonstrated that on average, birds that live in cold climates have a smaller bill.

Because the tufted puffins studied by Schraft live in Alaska, a smaller bill would have been, evolutionary speaking, the most logical outcome. However, competing needs might explain why puffins buck this trend.

"Overheating can be a big problem for seabirds who need to fly long distances to feed their chicks during breeding season," says Schraft. "Puffins may have been able to overcome this problem by evolving a larger bill."

Since 2013, a European Union (EU) moratorium has restricted the application of three neonicotinoids to crops that attract bees because of the harmful effects they are deemed to have on these insects. Yet researchers from the CNRS, INRA, and the Institut de l'Abeille (ITSAP) have just demonstrated that residues of these insecticides--and especially of imidacloprid--can still be detected in rape nectar from 48% of the plots of studied fields, their concentrations varying greatly over the years. An assessment of the risk posed to bees, based on health agency models and parameters, has revealed that for two out of five years, at least 12% of the fields were sufficiently contaminated to kill 50% of the bees and bumblebees foraging on them. The researchers' findings are published in Science of the Total Environment (28 November 2019).

The role of neonicotinoids in the decline of bees led to a 2013 EU moratorium limiting the use of three insecticides--clothianidin, imidacloprid, and thiamethoxam--on crops attracting pollinating bees. In September 2018, this was followed by a total ban on their application to any outdoor crop in France. Yet neonicotinoids are frequently detected on wildflowers[1] and untreated crops,[2] suggesting their dispersion within the environment after agricultural use.

To investigate this further, researchers from the Chizé Centre for Biological Studies (CNRS / La Rochelle University); INRA units Abeilles, Paysages, Interactions et Systèmes de Culture (APIS) and Abeilles et Environnement (AE); and ITSAP looked for and quantified neonicotinoid residues in nectar from 291 plots (536 samples) of winter rape for the five years following adoption of the moratorium, from 2014 to 2018.

Their first observation was that the three neonicotinoids in question could be found in the samples. Imidacloprid in particular was detected each year, in 43% of the analysed samples (corresponding to 48% of the fields), with no downward trend over the years but great variation between them. In 2016, over 90% of the sampled plots tested positive, versus 5% in 2015. Residue levels depend on the type of soil and are higher when there is more precipitation, but they do not appear to be directly linked to the spatial or temporal proximity of potentially treated crops. Though 92% of the positive samples only contained 0.1 to 1 ng/mL of imidacloprid, maximum concentrations in some cases exceeded those reported for treated plots, reaching as high as 70 ng/mL.

Using this data, mortality assessments based on health agency models and parameters suggest a non-negligible risk for pollinating bees. For domestic bees, risk peaked in 2014 and 2016, when around 50% of the pollinators were likely to die from imidacloprid in 12% of the plots studied. In those years, 10% to 20% of the plots exhibited a level of contamination associated with the same risk of death for bumblebees and solitary bees. These findings indicate that persistent use of neonicotinoids with certain crops in open fields threatens bees and pollinators frequenting other, untreated crops. They confirm that imidacloprid residues remain in the environment, and spread, even turning up in rape nectar, even though neonicotinoids have not been applied to rape crops since 2013. They also justify the reinforcement of pesticide controls by the total ban on the use of neonicotinoids for any outdoor crop in France, adopted in September 2018.

This study relied on access to the Zone Atelier Plaine & Val de Sèvre, a unique CNRS site in west central France (Deux-Sèvres, Nouvelle-Aquitaine).

Oil and gas pipelines have become polarizing issues in Canada, but supporters and detractors alike can agree that the safer they are, the better.

Unfortunately, integrity and health are ongoing and serious problems for North America's pipeline infrastructure. According to the US Department of Transportation (DOT), there have been more than 10,000 pipeline failures in that country alone since 2002. Complicating safety measures are the cost and intensity of labour required to monitor the health of the thousands of kilometres of pipelines that criss-cross Canada and the United States.

In a recent paper in the Journal of Pipeline Systems Engineering and Practice, researchers at Concordia and the Hong Kong Polytechnic University look at the methodologies currently used by industry and academics to predict pipeline failure -- and their limitations.

"In many of the existing codes and practices, the focus is on the consequences of what happens when something goes wrong," says Fuzhan Nasiri, associate professor in the Department of Building, Civil and Environmental Engineering at the Gina Cody School of Engineering and Computer Science.

"Whenever there is a failure, investigators look at the pipeline's design criteria. But they often ignore the operational aspects and how pipelines can be maintained in order to minimize risks."

Nasiri, who runs the Sustainable Energy and Infrastructure Systems Engineering Lab, co-authored the paper with his PhD student Kimiya Zakikhani and Hong Kong Polytechnic professor Tarek Zayed.

Safeguarding against corrosion

The researchers identified five failure types: mechanical, the result of design, material or construction defects; operational, due to errors and malfunctions; natural hazard, such as earthquakes, erosion, frost or lightning; third-party, meaning damage inflicted either accidentally or intentionally by a person or group; and corrosion, the deterioration of the pipeline metal due to environmental effects on pipe materials and acidity of oil and gas impurities. This last one is the most common and the most straightforward to mitigate.

Nasiri and his colleagues found that the existing academic literature and industry practices around pipeline failures need to further evolve around available maintenance data. They believe the massive amounts of pipeline failure data available via the DOT's Pipeline and Hazardous Materials Safety Administration can be used in the assessment process as a complement to manual in-line inspections.

These predictive models, based on decades' worth of data covering everything from pipeline diameter to metal thickness, pressure, average temperature change, location and timing of failure, could provide failure patterns. These could be used to streamline the overall safety assessment process and reduce costs significantly.

"We can identify trends and patterns based on what has happened in the past," Nasiri says. "And you could assume that these patterns could be followed in the future, but need certain adjustments with respect to climate and operational conditions. It would be a chance-based model: given variables such as location and operational parameters as well as expected climatic characteristics, we could predict the overall chance of corrosion over a set time span."

He adds that these models would ideally be consistent and industry-wide, and so transferrable in the event of pipeline ownership change -- and that research like his could influence industry practices.

"Failure prediction models developed based on reliability theory should be realistic. Using historical data (with adjustments) gets you closer to what actually happens in reality," he says.

"They can close the gap of expectations, so both planners and operators can have a better idea of what they could see over the lifespan of their structure."

Topological materials have become a hot topic in quantum materials research, as they have potential applications for quantum information and spintronics. This is because topological materials have strange electronic states in which an electron’s momentum is connected to its spin orientation, something that can be exploited in new ways to encode and transmit information. One type of topological material, called a magnetic Weyl semimetal, is attracting interest because of its potential ability to be manipulated with magnetic fields.

Because these materials are so new, however, it has been difficult for scientists to identify and characterize Weyl semimetals. A recent theory and modeling study from scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory may not only give researchers an easier way of finding Weyl semimetals, but also a way to more easily manipulate them for potential spintronic devices.

“We want to know if there is some signature in the semimetal that we can see if we attempt to run a current through it, something that is characteristic of it being a Weyl semimetal.” — Argonne materials scientist Olle Heinonen

Previous attempts to investigate Weyl semimetals relied on a complicated technique requiring an X-ray or a laser source and carefully prepared samples. To simplify the observation of semimetals, Argonne researchers instead proposed to use the relationship between two essential properties — electronic spin and charge — to reveal the nature of the topological materials and give scientists new ways to use them.

“We want to know if there is some signature in the semimetal that we can see if we attempt to run a current through it, something that is characteristic of it being a Weyl semimetal,” said Argonne materials scientist Olle Heinonen.

To generate a charge current in the Weyl semimetal, Heinonen proposed first to inject a spin current at the interface between a normal metal and the Weyl semimetal. While the spin current involved an influx of electrons with spins pointed in a particular direction, there were no net charges injected because electrons of opposite spin were being pulled the other way.

“You can think of it like having two swimmers going opposite ways in a swimming pool, one doing the freestyle and one doing the backstroke,” he said. “There’s no net direction of swimming, but there is a net amount of freestyle.”

By moving spins preferentially from the normal metal into the Weyl semimetal, the researchers found that the semimetal needed to find ways to accommodate electrons with particular spins in its electronic structure. “You can’t just stick any electron wherever you want,” Heinonen said.

Instead, the researchers found that the electrons tend to redistribute their spins into those places that are available and energetically favorable. “You might not be able to fit all your spin into one particular electronic state, but you can fit fractional amounts of spin in different states that add up to the same amount,” Heinonen said. “Imagine if you have a wave that hits a rock; you still have the same amount of water moving, just in different directions.”

When the electron “breaks up” in this manner when it encounters the Weyl semimetal, the different resulting electronic states travel with different speeds, generating a charge current. Depending on the direction in which this current is measured — say, from top to bottom or from left to right — scientists saw different results.

“How the electron breaks up is related in a very sensitive way to the relationships between energy, momentum and spin in the magnetic Weyl semimetal,” Heinonen said. “As a result, how the direction of the charge current changes is directly related to the properties of the Weyl semimetal, allowing you to determine its topological characteristics.”

Seeing the anisotropy, or the difference in charge current when measured in different directions in the Weyl semimetal, gives researchers two pieces of information. First, it reveals the Weyl nature of the material, but perhaps more importantly it allows researchers to tune the properties of the material. “The response we see is uniquely interesting because it’s a Wey lsemimetal, and because it has this interesting anisotropic response, we can probably exploit that in some devices,” Heinonen said. “We’re out a little bit ahead of the curve as far as people actually making many Weyl semimetals, but this gives us a cheap way of testing and experimenting with a type of material that is likely to become more popular.”

A paper based on the study, “Spin-to-charge conversion in magnetic Weyl semimetals,” appeared in the Nov. 1 issue of Physical Review Letters. Argonne’s Ivar Martin, Shulei Zhang, now an Assistant Professor of Physics at Case Western Reserve University, and Anton Burkov of the University of Waterloo, also collaborated on the study.

Some community parks are square, a reflection of the city block where they're located -- but irregularly shaped parks reduce the mortality risk of residents who live near them, concluded a study by Huaquing Wang, a Ph.D. Urban and Regional Sciences student and Lou Tassinary, professor of visualization.

"Nearly all studies investigating the effects of natural environments on human health are focused on the amount of a community's green space," said the scholars in a paper describing their project. "We found that the shape or form of green space has an important role in this association."

Their paper was published in the Nov. 2019 issue of The Lancet Planetary Health.

In the study, Wang and Tassinary performed statistical analyses of Philadelphia land cover data to assess links between landscape spatial metrics and health outcomes.

They found that residents in census tracts with more connected, aggregated, and complex-shaped greenspaces had a lower mortality risk.

"Our results suggest that linking existing parks with greenways or adding new, connected parks might be fiscally accessible strategies for promoting health," said Wang and Tassinary.

"We showed that the complexity of the park shape was positively associated with a lower risk of mortality," they said in the paper. "This association might be attributable to the increased number of access points provided by complex-shaped green spaces."

Irregularly shaped parks are either designed that way or shaped by the parcel they're established in, said Wang. Lower mortality risk wasn't associated with any particular form, but the data supports the idea that the more complex the park shape, the better, she said.

The relationship between park shape and mortality is important to city designers and planners who seek to create healthier living environments, they said in the paper.

"Our findings bring us closer to understanding the mechanisms underlying the protective effects of green space on mortality," they said.

Glycosylation -- the attachment of sugars to proteins -- plays a critical role in both cellular function and in the development of therapeutics, like vaccines.

But because researchers have used mammalian cells to create the biosynthetic pathways (sets of enzyme catalysts) to build and study these sugar structures, the process has historically taken a long time and has required specialized laboratory equipment.

Northwestern Engineering researchers have now developed a quick, cell-free system to build and study these pathways. Called GlycoPRIME, the system could lead to faster development of therapeutics and a new, modular way to make medicines on demand in resource-limited settings.

"This is an exciting new method that accelerates the design and engineering of potential medicines and vaccines using glycosylation," said Michael Jewett, the Charles Deering McCormick Professor of Teaching Excellence, professor of chemical and biological engineering, and director of Northwestern's Center for Synthetic Biology, who led the research. "It's opening a new book to engineer proteins not seen in nature with specific applications."

The results were published November 27 in the journal Nature Communications. Milan Mrksich, the Henry Wade Rogers Professor of Biomedical Engineering, Chemistry, and Cell and Molecular Biology at Northwestern's McCormick School of Engineering, is a co-author on the paper. He is also the interim vice president for research at Northwestern.

A new approach to discovering glycosylation pathways

Glycosylation is important in the development of protein medicines, which include everything from anti-cancer drugs like Herceptin to flu and tetanus vaccines. Sugar structures allow these proteins to remain stable while enabling them to perform tasks, like attack a cancer cell or retrain the immune system.

Developing these medicines has generally required many years and a laboratory with highly specialized equipment to grow mammalian cells. These mammalian cells naturally produce glycosylated proteins, but are slow-growing and can be difficult to engineer, limiting the number and diversity of glycosylation structures that can be built and tested.

Jewett's lab has developed cell-free systems that create enzymes needed to create certain proteins, but up until now, these processes could not create glycosylated products without the need to reengineer living cells.

Weston Kightlinger, a PhD student in the Jewett lab, developed a new approach to build, test, and assess sets of enzymes that can modularly build sugars for protein therapeutics. The process involves producing and then mixing and matching enzymes in test tubes to discover and understand which enzymes are needed to build desired sugar structures.

Kightlinger likens the process to building a flying machine. Instead of building a bird, which is complex and difficult to create, humans build airplanes, which are much simpler than birds but can be engineered to fly just the same. "We are pipetting liquids instead of rebuilding cells," he said. "Doing this, you can go from DNA to a glycoprotein in a matter of hours rather than weeks."

In just a few months, Kightlinger used the system to construct 37 pathways, creating 23 unique sugar structures, 18 of which have never been synthesized on proteins.

"We can now mix and match to build biosynthetic pathways an order of magnitude faster than what has been conventionally done," Jewett said. "The dream is to create new-to-nature glycoproteins that could be made on-demand to develop new types of protein medicines."

A new method for developing therapeutics and vaccines

The researchers used this process to develop a protein vaccine candidate modified with a sugar structure that could trigger the immune system, as well as a therapeutic antibody fragment with a sugar that can stabilize proteins as they circulate in the body. Future works will use other pathways developed in this paper to create glycosylated protein vaccines and therapeutics that can target certain areas within the body. The system could also be used to provide modular, on-demand biomanufacturing platforms that provide medicines or vaccines in resource-limited settings.

"Because this system is so robust and simple, it can teach us more about how these sugar structures actually work," Kightlinger said. "That will allow us to optimize them to better understand which of these structures to pursue."

For decades, scientists have speculated about the origin of the electromagnetic radiation emitted from celestial regions that host black holes and neutron stars--the most mysterious objects in the universe.

Astrophysicists believe that this high-energy radiation--which makes neutron stars and black holes shine bright--is generated by electrons that move at nearly the speed of light, but the process that accelerates these particles has remained a mystery.

Now, researchers at Columbia University have presented a new explanation for the physics underlying the acceleration of these energetic particles.

In a study published in the December issue of The Astrophysical Journal, astrophysicists Luca Comisso and Lorenzo Sironi employed massive super-computer simulations to calculate the mechanisms that accelerate these particles. They concluded that their energization is a result of the interaction between chaotic motion and reconnection of super-strong magnetic fields.

"Turbulence and magnetic reconnection--a process in which magnetic field lines tear and rapidly reconnect--conspire together to accelerate particles, boosting them to velocities that approach the speed of light," said Luca Comisso, a postdoctoral research scientist at Columbia and first author on the study.

"The region that hosts black holes and neutron stars is permeated by an extremely hot gas of charged particles, and the magnetic field lines dragged by the chaotic motions of the gas, drive vigorous magnetic reconnection," he added. "It is thanks to the electric field induced by reconnection and turbulence that particles are accelerated to the most extreme energies, much higher than in the most powerful accelerators on Earth, like the Large Hadron Collider at CERN."

When studying turbulent gas, scientists cannot predict chaotic motion precisely. Dealing with the mathematics of turbulence is difficult, and it constitutes one of the seven "Millennium Prize" mathematical problems. To tackle this challenge from an astrophysical point of view, Comisso and Sironi designed extensive super-computer simulations --among the world's largest ever done in this research area--to solve the equations that describe the turbulence in a gas of charged particles.

"We used the most precise technique--the particle-in-cell method--for calculating the trajectories of hundreds of billions of charged particles that self-consistently dictate the electromagnetic fields. And it is this electromagnetic field that tells them how to move," said Sironi, assistant professor of astronomy at Columbia and the study's principal investigator.

Sironi said that the crucial point of the study was to identify role magnetic reconnection plays within the turbulent environment. The simulations showed that reconnection is the key mechanism that selects the particles that will be subsequently accelerated by the turbulent magnetic fields up to the highest energies.

The simulations also revealed that particles gained most of their energy by bouncing randomly at an extremely high speed off the turbulence fluctuations. When the magnetic field is strong, this acceleration mechanism is very rapid. But the strong fields also force the particles to travel in a curved path, and by doing so, they emit electromagnetic radiation.

"This is indeed the radiation emitted around black holes and neutron stars that make them shine, a phenomenon we can observe on Earth," Sironi said.

The ultimate goal, the researchers said, is to get to know what is really going on in the extreme environment surrounding black holes and neutron stars, which could shed additional light on fundamental physics and improve our understanding of how our Universe works.

They plan to connect their work even more firmly with observations, by comparing their predictions with the electromagnetic spectrum emitted from the Crab Nebula, the most intensely studied bright remnant of a supernova (a star that violently exploded in the year 1054). This will be a stringent test for their theoretical explanation.

"We figured out an important connection between turbulence and magnetic reconnection for accelerating particles, but there is still so much work to be done," Comisso said. "Advances in this field of research are rarely the contribution of a handful of scientists, but they are the result of a large collaborative effort."

Other researchers, such as the Plasma Astrophysics group at the University of Colorado Boulder, are making important contributions in this direction, Comisso said.

NASA-NOAA's Suomi NPP satellite passed over Tropical Storm Kammuri in the Northwestern Pacific Ocean and found several areas of very strong thunderstorms.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided an infrared image of the storm on Nov. 27 at 0424 UTC (Nov. 26 at 11:24 p.m. EST). Infrared imagery reveals cloud top temperatures, and the higher the cloud top, the colder it is, and the stronger the storm.

The VIIRS instrument found several areas within where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius), indicating powerful storms. Kammuri continued to strengthen and consolidate. The most powerful thunderstorms were located around the center of circulation and in a fragmented band of thunderstorms north of the center. Storms with cloud tops that cold have been found to generate heavy rainfall.

At 4 a.m. EST (0900 UTC7 p.m. CHST, Guam local time) on Nov. 27,  the National Weather Service in Tiyan, Guam noted the center of Tropical Storm Kammuri was located near latitude 11.7 degrees north and longitude 140.6 degrees east. Kammuri is centered about 130 miles north-northeast of Ulithi, 135 miles north of Fais, 230 miles northeast of Yap and about 310 miles west-southwest of Guam.

Guam, Rota, Tinian, and Saipan are no longer under a Tropical Storm Warning. However, a flash flood watch remains in effect for Guam and the Northern Marianas.

Kammuri is moving west at 16 mph. It is expected to make a turn toward the north-northwest with a decrease in forward speed over the next 24 hours. Maximum sustained winds remain at 65 mph. Tropical storm force winds extend outward from the center up to 240 miles to the northeast and up to 155 miles elsewhere.

Kammuri is forecast to intensify through Thursday possibly becoming a typhoon. It is also forecast to turn north and then head west after two days toward the Philippines.

Typhoons and hurricanes are the most powerful weather event on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

Active cooling is crucial in most modern technologies, ranging from microprocessors in data centers to turbines and engines. Forced convection cooling, which circulates a coolant fluid over the surface of a hot object, is effective for meeting such cooling requirements but demands a pumping power to send the coolant through the heat generating section. However, active cooling ? fast removal of a large quantity of thermal energy in the heat source under a large temperature difference ? promptly destroys the free-energy component of the thermal energy, which is an energy portion that can be converted to an electric work. This issue concomitant with forced convection cooling has remained unaddressed despite the widespread use of forced convection cooling in the current world.

One specific method for converting wasted heat ? the heat that doesn't need to be actively removed ? into electrical energy through liquid chemical reactions has been studied for several decades. This method, called thermo-electrochemical conversion, involves the submergence of two electrodes held at different temperatures in a liquid electrolyte encased in a closed vessel, where a reversible reduction-oxidation ("redox") reaction occurs. This reaction generates an electric current through an external circuit. Research on thermo-electrochemical conversion has been mostly carried out for static fluids.

In this study, a team of researchers from Tokyo Institute of Technology integrated thermo-electrochemical conversion with forced convection cooling to partly recover the aforementioned free-energy portion, presently lost during forced-convection cooling, in the form of electric power. In the cell developed by these researchers, the electrolyte liquid is flown as a coolant between two parallel electrodes, one of which is a heat-releasing object to be cooled. The redox reaction occurring in the cell generates electricity; this electricity can be used to drive the coolant flow through the cell. This work delves into uncharted territory, as the concept and feasibility of self-sustaining liquid-cooling system have not been previously demonstrated.

The researchers carried out detailed studies to elucidate how the cooling and power generation works in this type of forced-flow thermo-electrochemical system. These novel findings are expected to provide a basic strategy for scaled-up future applications. "Although the prototype cell developed in this study was small and thus the power generation performance was limited, this technology has much scope for improvement through optimizing the geometry of the liquid channel, electrode material, and the redox chemicals," remarks Prof. Yoichi Murakami, the principle investigator of this project.

Through further studies, this concept proposed by the researchers can hopefully find its application in near future, providing a new technological platform for forced convection cooling. "Through this approach, we can partially recover the free energy portion of the thermal energy currently lost during forced convection cooling, and this acquired electric power can be used for pumping the coolant in forced convection cooling," concludes Prof. Murakami.

Scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed a way to make Colloidal Quantum Dots produce laser light with the help of an electric field.

Colloidal Quantum Dots (CQDs) are semiconductor nanoparticles that can generate vivid and saturated colours of light efficiently, which are used to make display screens of many electronic devices.

Though CQDs should be promising as laser materials, they are not yet practical since they need to be powered by another source of light energy - a method known as optical pumping. However, this renders them too bulky for use in semiconductor electronics.

Over the last few years, researchers have tried various approaches to make it easy to use CQDs in lasers, including electrochemical methods or chemical doping. These approaches require the use of harsh chemical solvents or oxygen-free environments in their production, and so have been limited to lab-scale experiments.

In a paper published in Science Advances, NTU Assistant Professor Steve Cuong Dang together with PhD student Yu Junhong, have demonstrated how an electric field can help CQDs emit laser light while using only a fraction of the energy traditionally required to drive a laser.

In their experiments, the NTU scientists embedded CQDs between two electrodes, which provides an electric field to control and change the properties inside the CQDs. By manipulating these properties, the scientists lowered the energy threshold needed for lasing by around 10 per cent, bringing the prospect of CQD lasers closer to reality.

This threshold reduction is the first time researchers have lowered it using an electric field, instead of difficult-to-employ electrochemical methods.

Being able to build low-cost, small size lasers that are "electrically driven" in a wide range of colours is the holy grail for many optical and optoelectronic researchers. Lasers are the backbone technology for various industries including medical, security and consumer electronics, and are essential to the development of laser televisions.

"Our successful experiment brings us one step closer towards developing single-material full-colour lasers that can be electrically pumped. That achievement would eventually make it possible to put lasers on chip integrated systems used in consumer electronics and the Internet of Things (IOTs)" said Asst Prof Dang, from the School of Electrical and Electronic Engineering (EEE).

Benefits of Colloidal Quantum Dots

Colloidal Quantum Dots are easily and economically produced in simple liquid-phase chemical syntheses, and their optical and electronic properties can be altered and controlled by varying the particle size.

Colloidal nanomaterials are attractive to laser makers due to their low-cost, tune-able emission colour and high emission efficiency. However getting them to lase currently requires fast, intense and coherent optical pumping, whereas electric pumping is slow, weak and incoherent.

Together with his collaborators Prof Hilmi Volkan Demir and Assoc Wang Hong from EEE, and Prof Sum Tze Chien from the School of Physical and Mathematical Sciences, Asst Prof Dang showed that applying an electric field lowers the lasing threshold of CQDs, and could lead to viable electrically-pumped CQD lasers.

Prof Demir said, "The next big challenge in laser research is to develop nano-scale lasers and integrate them into on-chip photonic devices and ultrasensitive sensors. This would bring significant impacts to modern society especially in data and information processing, that is driving the 4th industrial revolution. Achieving it would be a major advance within Singapore's Industry 4.0 transformation."

The team is now looking to research further into making tiny CQD lasers on a chip and to work with industry partners keen to develop the technology into proof-of-concept devices with practical applications.

IMET RAS in cooperation with Lomonosov Moscow State University and Belgorod State University have investigated the thermal stability of the synthetic hydroxyapatite (HA) - the analogs material of human bone tissue. The obtained results have demonstrated that Al3+ doping of the HA structure in the tiny amounts enhanced its thermal stability and biocompatibility. This lead to apply this material as a coating for implants and for high-temperature bioceramics creation. In the cooperation with Kazan Federal University and Kazan Institute of Biochemistry and Biophysics of Kazan Science Centre of the Russian Academy of Sciences, the scientists described the HA structure properties and predicted the model of the Al incorporation in the HA crystal lattice. Scientists from the Federal State Budgetary Institution National Medical Research Radiological Center of the Ministry of Health of the Russian Federation carried out the certification of sintered materials in vitro, which showed an improvement in the biological characteristics of aluminum-containing materials. The results were published in Journal of Materials Research and Technology and the Journal of Physical Chemistry B.

HA is the main mineral of the native bone tissue. Scientists have been studied the synthesis and properties of HA in IMET RAS since 1990. HA powder was synthesized and heat-treated at high temperature for bone tissue implants engineering. It decomposes at the temperature higher than 1100 °C losing OH-groups which follows by phase transformation and formation of undesirable phases.

Scientists from IMET RAS have been investigated the influence of different cations on the thermal stability of HA. Increasing the thermal stability of HA will allow it to be applied as a coating for Al2O3 or Ti6Al14V implants and to obtain dense and porous high-temperature bioceramics. In the first article, it was found that the introduction of aluminum up to 1 mol % can ensure the preservation of the pure HA phase at 1200 °C, as well as provide the predominant formation of HA (up to 88 wt.%) at 1400 °C. A further increase of Al concentration in the HA leads to destabilization of the crystal lattice and the decrease of thermal stability, up to a complete transformation from HA to tricalcium phosphate at 900 °? in the case of substitution of 20 mol. % Al. To identify this effect a wide range of material studies was carried out together with scientists from Lomonosov Moscow State University and Belgorod State University. The effect of aluminum on the parameters of the crystal lattice, the intensity of vibrations of functional groups in the molecules were studied and the mass loss during heating was found. The obtained results became the basis for the diagram of the thermal stability of HA, which can help engineers and technologists in the determination of the temperature conditions of sintering or coating in order to preserve the single-phase state of the substance.

In the second article, the influence of aluminum on electron paramagnetic resonance and electron-nuclear paramagnetic resonance was studied. Together with colleagues from Kazan Federal University and Kazan Institute of Biochemistry and Biophysics of Kazan Science Centre of the Russian Academy of Sciences a model of the introduction of aluminum cations into the HA lattice was predicted using the theory of functional density. Scientists from the Federal State Budgetary Institution National Medical Research Radiological Center of the Ministry of Health of the Russian Federation carried out the certification of sintered materials in vitro, which showed an improvement in the biological characteristics of aluminum-containing materials compared to pure HA. Thus, the effect of aluminum on the crystalline structure, thermal and biological behavior of HA was experimentally studied.

Scientific researcher Margarita Goldberg, PhD said: "In spite of the fact that the information about the effect of aluminum in the form of compounds on the human body is controversial nowadays, Al is using as a basis for injections, a drug carrier, a doping cation for creating implants. Recent investigations have shown that the introduction of small doses of aluminum into the HA lattice in the form of a cation, rather than in a metallic state, contributed to the improvement of biocompatibility and the growth of the matrix properties of the implant surface".

SEATTLE, November 26, 2019 -- Fire ants build living rafts to survive floods and rainy seasons. Georgia Tech scientists are studying if a fire ant colony's ability to respond to changes in their environment during a flood is an instinctual behavior and how fluid forces make them respond.

Hungtang Ko and David Hu will present the science behind this insect behavior, focusing their discussion on how the living raft changes size under various environmental conditions at the American Physical Society's Division of Fluid Dynamics 72nd Annual Meeting on Nov. 26.

The red imported fire ant (Solenopsis invicta) can optimize its ability to repel water by linking its body together with tens of thousands of its peers to build massive floating colonies.

"We think the response is an active process. Fire ants are able to sense the change in force when different fluid conditions are applied," Ko said.

The researchers found different fluid behaviors, such as vortexes, could change the size of the fire ant raft in several ways. They discovered rotation of water can inhibit exploratory behaviors of individual fire ants, while centrifugal motion does not influence the colony.

"Our current hypothesis is that they explore less, because they need to form a stronger bond with their neighbors. We are still working on testing the hypothesis," Ko said. "We think the independent response in individuals is enough in leading to the system-level deformation that we observe."

Stronger physical bonds between individual fire ants lead to durable and safer rafts. The individual ant's ability to respond to environmental changes is crucial to the sustainability of their raft and the survival of the colony.

The session, "Shrinking spinning fire ant rafts," will be presented at 10:31 a.m. Pacific (U.S.) on Tuesday, Nov. 26 in Room 613 as part of a session on biological fluid dynamics and collective behavior.

In the aftermath of the notorious accidents in the history of nuclear energy at Three Mile Island (1979), Chernobyl (1986) and Fukushima (2011), where all three have turned into devastating disasters due to meltdown in the core of a reactor, leading in turn to the release of radiation into the environment, many countries around the world have already pledged to a nuclear power phase-out.

However, while actions towards the closure of all nuclear power plants in only a few decades' time are already well underway, the alternative energy sources currently in operation have some major drawbacks: they rely mainly on non-renewable resources, produce significantly less energy compared with nuclear power plants and, most importantly, are considered to be amongst the main contributors of carbon emissions and, thereby, the climate crisis which humanity is now set to battle.

Nevertheless, a future powered by nuclear energy might be neither a lost cause, nor a game of "Russian roulette", according to the research team of Francesco D'Auria (University of Pisa, Italy), Nenad Debrecin (University of Zagreb, Croatia) and Horst Glaeser (Global Research for Safety, Germany). In a recent paper, published in the open-access peer-reviewed journal Nuclear Energy and Technology and the result of 30-40 years of collaboration, they propose a new safety barrier to be implemented in large Light Water Reactors around the world. Coming at a fraction of the cost of the already obsolete one that it is about to replace, this barrier is expected to reduce the probability of core melt to that of a large meteorite hitting the site.

With their new technological solution, these scientists aim to bring together research findings from the last few decades, mostly in relation to accident analysis capabilities and nuclear fuel material performance, as well as the concepts of the very pioneers who developed the nuclear technology in the past century. The proposal is based on studies and discussions from the 11th Scientific and Technical Conference "Safety Assurance of NPP with VVER" (Russia, May 2019) and the International Conference on Nuclear Power Plants, Structures, Risk & Decommissioning, NUPP2019 (United Kingdom, June 2019). As a result, they hope to regain public confidence in nuclear power - an efficient and sustainable source of renewable energy, as well as bridging the gaping chasm between what we have learnt over the years about nuclear energy and technology and what is being implemented in practice.

Amongst the up-to-date research findings and knowledge to be implemented in the novel technological solution are the recently discovered nuclear fuel structural weakness, as well as a more elaborate Extended Safety Margin Detection (E-SMD), which allows for an emergency shutdown of a reactor, following even low and very low probability events. It also provides advance information to the operators about the actions needed to prevent or mitigate possible damage. The recruitment of an Emergency Rescue Team (ERT) is also proposed to consist of a group of highly trained and specialised rescuers who will be in possession of suitable machinery and equipment, as well as access to each nuclear reactor installed within an assigned geographic region and who will be able to reach any of the sites within an hour or execute a remote shutdown of the reactor.

In their study, the researchers go on to explain how and why exactly these features would have prevented core melt and the eventual nuclear disasters at each of the three notorious nuclear power stations.

In the case of the Three Mile Island accident: the most devastating accident in US commercial nuclear power plant history, considered to be the result of a rather typical combined failure, an alarm from E-SMD detectors would have triggered the emergency shutdown of the unit well before the event.

In Chernobyl, where critical human errors are found to have led to the accident, an intervention from the ERT: a remotely controlled shutdown and perhaps the deployment of the military would have prevented the consequent catastrophe.

Extended core damage at the Fukushima Units 1 to 3 would have also been prevented thanks to the combination of emergency alerts and prompt action by the ERT.

The researchers also note that, in spite of the notoriety of the three nuclear disasters, there have been about 500 safely operated nuclear power plant units since the demonstration of the capability to control the fission reaction in 1942 and the connection of nuclear fission driven electricity generator to the electrical grid in 1954. On top of that, there have been a few thousand accident-free reactors used for purposes different from electricity production, including research, production and marine propulsion.

"The industry and/or the Government of responsible Countries where applicable, become the main players for the possible implementation of the ideas in this paper," the scientists write in conclusion. "A strategy is needed in this connection: academia and research institutes willing to be engaged into practical applications of the nuclear technology should become actors."