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Lenses are one of the most commonly used optical components in daily life, including eyeglasses, microscopic objectives, magnifying glass, and camera lenses. Conventional lenses are based on the principle of light refraction, using different materials, spherical surfaces and spatial positions to achieve the control of light. The fabrication of conventional lenses including the processes of material selection, cutting, rough grinding, fine grinding, polishing, and testing. In order to minimize the aberrations including the chromatic aberration, spherical aberration and astigmatisms, it is necessary to stack multiple layers of lenses to form compound lenses, leading to the complexity and cumbersomeness of current camera equipment.

Therefore, tremendous effort has been devoted into the development of ultrathin flat lenses. Unlike conventional lenses, flat lenses use nanostructures to modulate light. By controlling the optical properties and the spatial position of each nano-element, advanced functions, such as achromatic and aberration-free focusing, high spatial resolution and special focal intensity distributions can be achieved. However, when the material thickness is reduced to the subwavelength scale, the insufficient phase or amplitude modulation based on the intrinsic refractive index and absorption of the materials results in poor lens performance.

In a new paper published in Light Science & Application, a team of scientists, led by Prof. Baohua Jia at Centre for Translational Atomaterials, Swinburne University of Technology, Australia, Prof. Qiaoliang Bao formerly at Monash University, Prof. Chengwei Qiu at National University of Singapore and co-workers have developed an innovative method to fabricate high performance lenses in monolayer two dimensional transitional metal dichalcogenide (TMDC) material by using a femtosecond laser to pattern nanoparticles. The lens has a sub-wavelength resolution and a focusing efficiency of 31%, laying the foundation for ultimately thin optical devices for use in nano-optics and on-chip photonic applications.

Although lenses made from multilayer TMDCs have been demonstrated before, when their thickness is reduced to the sub-nanometer scale, their insufficient phase or amplitude modulation results in focusing efficiencies of less than 1%. The international team discovered that it is possible to generate nanoparticles by using a femtosecond laser beam to interact with the monolayer TMDC material, which is significantly different from the process produced by a continuous wave laser. When the laser pulse is so short that the entire material remains cold after laser process, the nanoparticles can firmly attach to the substrate. The nanoparticles show very strong scattering to modulate the amplitude of light. Therefore, the lens made from the nanoparticles can provide subwavelength resolution and high efficiency, which allows the team to demonstrate diffraction-limited imaging by using the lenses.

Monolayer is the thinnest form of a material, which is the ultimate physical thickness limit. By using the monolayer for the lens fabrication, the process demonstrated in this study consumed the least material meeting the theoretical limitation. More importantly, the femtosecond laser fabrication technique is a one-step simple process, without the requirements of high vacuum or special environment, thus it provides the simplest way to fabricate an ultrathin flat lens. As a result, the lens can be easily integrated into any photonic or microfluidic devices for broad applications.

"We have used the thinnest material in the world to fabricate a flat lens, and prove that the good performance of the ultrathin lens can lead to high resolution imaging. It shows enormous potential in different applications, such as eyeglasses, microscopy lenses, telescopes and camera lenses. It is foreseeable that by using this technique, the weight and size of camera lenses can be significantly reduced in the near future." Said Dr Han Lin, the first author from the Centre for Translational Atomaterials, Swinburne University of Technology.

"We are excited to see unique outcome from femtosecond laser processing 2D materials. It opens up new possibility to fabrication photonic devices using scalable method." Added by Prof. Baohua Jia, Director of Centre for Translational Atomaterials.

"We can integrate the monolayer 2D material lens onto desired devices by simply attaching the material then using a femtosecond laser to perform fabrication. The entire process is simple, and the method is flexible and low cost. Thus, we also see the great application potential of the method." Commented by Prof. Qiaoliang Bao formerly at Monash University.

"We design our lens in such a way that image can be found at different focal planes, with different magnifications. This mechanism can be readily used to develop an optical zoom lens that is required in all cellphone cameras. Currently, lenses with different focal lengths are used to achieve different zoom function. However, our lenses can achieve different zoom rates simply with one design." Prof. Chengwei Qiu from National University of Singapore forecasts.

Native to India, teak is the go-to species for reforestation in Central America. But teak often underperforms in the nutrient poor soils that dominate tropical landscapes. To discover if the timber value of teak plantations grown on poor soils can be increased, scientists at the Smithsonian Tropical Research Institute interplanted rosewood and amarillo, both economically valuable native tree species.

Native trees are well-adapted to local environmental conditions, resisting diseases and insect pests. Rosewood (Cocobolo, Dalbergia retusa) is typically sold to instrument makers and craftspeople for a higher price than teak is sold for. Rosewood trees also improve the soil by pulling nitrogen gas out of the air and converting it into fertilizer for itself and neighboring trees. Despite its timber value, rosewood is rarely cultivated and is more often poached from protected areas.

Although amarillo (Terminalia amazonia) is highly valued in Panama as a hardwood tree that grows fast and straight in conventional planting conditions--even in full sun--it has never been formally tested in mixtures with teak and rosewood.

Previous studies predicted that other tree species might not grow among teak trees because teak needs so much water and the roots produce chemicals that may impede the growth of other plants.

As part of the Smithsonian's 700-hectare Agua Salud Project, the largest reforestation experiment of its kind, researchers planted 30 hectares of teak in 2008. Evaluations in 2013 and 2016 confirmed that teak did not do well in Central Panama's nutrient-poor, clay soils.

To improve the profitability and environmental services of the plantation, scientists planted rosewood and amarillo seedlings among the teak trees in 2015. Although researchers added a handful of organic matter and a handful of NPK fertilizer to each seedling as it was planted, far less time and labor was involved than in the establishment of the teak plantation. They measured the seedlings in 2016 and again in 2017.

Virtually all of the rosewood seedlings survived across the site, despite several El Niño events that made this the driest period on record since 1925. Rosewood seedings seem to outperform amarillo seedlings initially, but the trees are predicted to catch up and surpass rosewood as time goes by, based on previous experiments.

"Amarillo will end up being bigger in stature than rosewood, but because of its incredible monetary value, the smaller rosewood will far surpass amarillo in terms of financial returns," said Katherine Sinacore, a post-doctoral fellow working on this species at STRI. "The idea that smaller is better, or in this instance massively more valuable, can be counterintuitive."

Along with the potential to better protect jaguars, migratory birds and other animals by increasing diversity at this continental crossroads, interplanting is also likely to improve water management, critical for the operation of the Panama Canal because both flooding and drought threaten canal infrastructure and transport of goods. While teak grown alone may not increase the "sponge effect," the ability of soils to absorb more water during storms and release it during dry periods, interplanting teak with native tree species may increase this valuable ecosystem service.

"Forestry research is often a waiting game," said Jefferson Hall, STRI staff scientist and director of the Agua Salud project. "Because it takes a long time for trees to grow, researchers plant trees and then wait many years to get results. We were delighted to find that rosewood and amarillo are growing and surviving just as well here at two years as they did in open-grown plantations."

In the future, researchers also will set up experiments to better understand how underground factors such as nutrient and water availability contribute to the success of interplanting with native trees.

"Exotic species like teak dominate timber plantations throughout Panama and the tropics worldwide," said Abigail Marshall, first author and graduate student at the University of Montana. "Our hope is that the early success of rosewood and amarillo interplanted in the Agua Salud Project's teak plantation will contribute to growing evidence for a strategy to increase the use of native tree species in the region and more broadly."

Tropical Depression 06W has been around for days, and continues to hold together as it moves in a westerly direction toward Taiwan in the Northwestern Pacific Ocean. NASA-NOAA's Suomi NPP satellite captured a visible image of the storm.

On Aug. 12, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP revealed a partially exposed low-level circulation with building thunderstorms over the western quadrant of Tropical Depression 06W. Satellite imagery also showed a weakly defined, broad center. The image was created by NASA Worldview website at NASA's Goddard Space Flight Center in Greenbelt, Md.

At 11 a.m. EDT (1500 UTC) on Aug. 12, the Joint Typhoon Warning Center (JTWC) noted Tropical Depression 06W (TD06W) was centered near latitude 5.0 degrees north and longitude 133.4 degrees east, approximately 349 nautical miles east-southeast of Kadena Air Base, Okinawa Island, Japan. 06W was moving to the west-southwest. Maximum sustained winds remained near 25 knots (29 mph/46 kph).

TD06W is expected to maintain intensity for another day and a half, when it will then weaken.

NASA Researches Tropical Cyclones

Hurricanes/tropical cyclones are the most powerful weather events 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.

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.

NASA's Aqua satellite obtained visible imagery of Hurricane Elida in the Eastern Pacific as it continued to weaken. Imagery revealed that Elida's eye had become covered as the storm embarks on a weakening trend over cooler waters.

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite captured a visible image of Hurricane Elida on Aug. 11 at 4:30 p.m. EDT and the eye had become obscured by high clouds. The image also revealed that the storm looked more elongated, another sign a storm is weakening. Satellite imagery was created using NASA's Worldview product at NASA's Goddard Space Flight Center in Greenbelt, Md.

Elida has moved into cooler waters, causing the storm to weaken. The hurricane have moved over waters of 23 to 24 degrees Celsius (73.4 to 75.2 degrees Fahrenheit). A hurricane needs sea surface temperatures of at least 26.6 degrees Celsius (80 degrees Fahrenheit) to maintain intensity.

Elida's Status on Aug. 12

At 5 a.m. EDT (0900 UTC) on Aug. 12, the center of Hurricane Elida was located near latitude 23.0 degrees north and longitude 117.7 degrees west. That's about 495 miles (800 km) west of the southern tip of Baja California, Mexico. Elida is moving toward the west-northwest near 13 mph (20 kph). A turn to the northwest along with some decrease in forward speed is expected to occur tonight. Maximum sustained winds are near 75 mph (120 kph) with higher gusts. The estimated minimum central pressure is 988 millibars.

Satellite imagery on Aug. 12 show that Elida's remaining deep convection, located northeast of the center of circulation, continues to shrink in coverage and wane in intensity.

Elida Still Causing Ocean Swells

The National Hurricane Center (NHC) said, "Swells generated by Elida are expected to affect portions of the coast of west-central Mexico and the southern Baja California peninsula during the next day or two.  These swells are likely to cause life-threatening surf and rip current conditions."

Elida's Forecast Calls for Quick Demise

NHC noted that Elida is expected to weaken quickly. "Rapid weakening is expected during the next day or so as Elida moves over colder water, and the cyclone is forecast to weaken to a tropical storm today and degenerate to a remnant low [pressure area] on Thursday."

About NASA's Worldview and Aqua Satellite

NASA's Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks "right now."

NASA's Aqua satellite is one in a fleet of NASA satellites that provide data for hurricane research.

Tropical cyclones/hurricanes are the most powerful weather events 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.

COLUMBUS, Ohio - Young children will pass up rewards they know they can collect to explore other options, a new study suggests.

Researchers found that when adults and 4- to 5-year-old children played a game where certain choices earned them rewards, both adults and children quickly learned what choices would give them the biggest returns.

But while adults then used that knowledge to maximize their prizes, children continued exploring the other options, just to see if their value may have changed.

"Exploration seems to be a major driving force during early childhood - even outweighing the importance of immediate rewards," said Vladimir Sloutsky, co-author of the study and professor of psychology at The Ohio State University.

"We believe it is because young children need to explore to help them understand how the world works."

And despite what adults may think, kids' search for new discoveries is anything but random. Results showed children approached exploration systematically, to make sure they didn't miss anything.

"When adults think of kids exploring, they may think of them as running around aimlessly, opening drawers and cupboards, picking up random objects," Sloutsky said

"But it turns out their exploration isn't random at all."

Sloutsky conducted the study with Nathaniel Blanco, a postdoctoral researcher in psychology at Ohio State. Their results were published online recently in the journal Developmental Science.

The researchers conducted two studies. One study involved 32 4-year-olds and 34 adults.

On a computer screen, participants were shown four alien creatures. When participants clicked on each creature, they were given a set number of virtual candies.

One creature was clearly the best, giving 10 candies, while the others gave 1, 2 and 3 candies, respectively. Those amounts never changed for each creature over the course of the experiment.

The goal was to earn as much candy as possible over 100 trials. (The children could turn their virtual candies into real stickers at the end of the experiment.)

As expected, the adults learned quickly which creature gave the most candies and selected that creature 86 percent of the time. But children selected the highest-reward creature only 43 percent of the time.

And it wasn't because the children didn't realize which choice would reap them the largest reward. In a memory test after the study, 20 of 22 children correctly identified which creature delivered the most candy.

"The children were not motivated by achieving the maximum reward to the extent that adults were," Blanco said. "Instead, children seemed primarily motivated by the information gained through exploring."

But what was interesting was that the children didn't just click randomly on the creatures, Sloutsky said.

When they didn't click on the option with the highest reward, they were most likely to go through the other choices systematically, to ensure they never went too long without testing each individual choice.

"The longer they didn't check a particular option, the less certain they were on its value and the more they wanted to check it again," he said.

In a second study, the game was similar but the value of three of the four choices was visible - only one was hidden. The option that was hidden was randomly determined in each trial, so it changed nearly every time. But the values of all four choices never changed, even when it was the hidden one.

Like in the first experiment, the 37 adults chose the best option on almost every trial, 94 percent of the time. That was much more than the 36 4- and 5-year-old children, who selected the highest-value option only 40 percent of the time.

When the hidden option was the highest-value option, adults chose it 84 percent of the time, but otherwise they almost never selected it (2 percent of the time).

Children chose the hidden option about 40 percent of the time - and it didn't matter if it was the highest value one or not.

"The majority of the children were attracted to the uncertainty of the hidden option. They wanted to explore that choice," Sloutsky said.

However, there were some individual differences in children, he noted. A few children, for example, acted much like adults and nearly always chose the highest-value option. In the second experiment, a few children almost always avoided the hidden option.

These variations may have to do with different levels of cognitive maturation in children, he said.

But it appears that all children go through a phase where systematic exploration is one of their main goals.

"Even though we knew that children like to run around and investigate things, we're now learning that there is a lot of regularity to their behavior," Sloutsky said.

"Children's seemingly erratic behavior at this age appears to be largely molded by a drive to stockpile information," added Blanco.

ORLANDO, Aug. 12, 2020 -- Many people have experienced a few nights of bad sleep that resulted in shifting attention spans, impulsive tendencies and hyperactivity the next day--all behaviors resembling ADHD. A new study found that this dynamic may also be linked to increased entrepreneurial behavior.

"We're not advocating depriving yourself of sleep to get ahead," said Jeff Gish, a professor of business at the University of Central Florida and co-author of the paper. "We're saying that there appears to be an interesting link between sleep and entrepreneurship. ADHD-like tendencies can be a benefit, rather than a hindrance in spurring ventures. But there is a potential downside. Even though sleep problems might lure an individual to an entrepreneurial career, if the sleep problems persist they can subsequently leave the individual without the cognitive and emotional competency to be an effective entrepreneur in-practice."

This paper suggests that sleep problems might nudge aspiring entrepreneurs to enter self-employment, but does not test the efficacy of subsequent venturing efforts.

Anecdotal information would appear to support the idea. According to multiple media reports, Bill Gates, Walt Disney, Richard Branson, Cisco Systems CEO John T. Chambers, actor Jim Carrey and Hollywood personality Howie Mandel all have ADHD. They are recognized impresarios who have significantly impacted their industries.

The results of the study published today in the journal Entrepreneurship Theory and Practice complement previous research that links sleep deprivation with lower productivity, lethargy and the hindrance of the longer-term success by suggesting that unhealthy sleep may have a limited upside.

Although the findings may engender contrasts to recent work advocating for adequate sleep, the results may also "contribute to the de-stigmatization of individuals whose social or personal circumstances place healthy sleep out of reach, [contributing to] greater social acceptance of diversity in sleep patterns."

The authors reached their findings by conducting four distinct studies that connected the dots from sleep quality to temporary ADHD-like tendencies and then to entrepreneurial intentions.

Sleep Deprivation and ADHD-like Tendencies

The first study, an experiment with 350 participants, had them fill out pre-experiment surveys. The participants were asked about their sleep and ADHD tendencies in the past six months. Questions aimed to gauge ADHD-like tendencies included things like:

How often do you have trouble wrapping up the fine details of a project, once the challenging parts have been done?

How often do you have difficulty getting things in order when you have to do a task that requires organization?

To gauge entrepreneurial intention, they were asked about their intention to start or acquire a business in the next 5-10 years.

Then the group was split into two and they filled out additional surveys under two conditions. One group had an uninterrupted night of sleep and woke up the next day to fill out the survey, which asked questions about their sleep quality, ADHD-like tendencies and intent to start a new business.

The second group filled out a total of 10 surveys beginning at 10 pm one night and every hour on the hour until 7 am the following day. This was to elicit sleep deprivation.

The results provided experimental evidence for a causal relationship between sleep problems and ADHD-like tendencies. "Our results suggest that disrupted sleep may help nudge people toward acting on their entrepreneurial ideas rather than continuing to ponder them," said Brian Gunia, a coauthor and associate professor at the Johns Hopkins Carey Business School.

Sleep, ADHD-like Tendencies, and Entrepreneurial Intentions: Studies 2-3

About 300 people filled out surveys that measured entrepreneurial intentions, followed by measures of ADHD-like tendencies, and sleep problems. Finally, they completed some demographic questions. The results were similar.

Poor sleep quality was associated with heightened ADHD-like tendencies, which was associated with heightened entrepreneurial intentions; poor sleep quality was also directly associated with heightened entrepreneurial intentions.

Extension to Practicing Entrepreneurs: Study 4

The previous studies looked at general populations, but the researchers wanted to see whether their predictions extended to practicing entrepreneurs. So, they surveyed a multi-national panel of 176 practicing entrepreneurs recruited from a mailing list maintained by a business planning software company on the U.S. West Coast. The participants in this group on average were 43 years-old, had started about two businesses and had been self-employed for at least seven years. Slightly more than half were men. They had the participants fill out similar surveys on sleep, ADHD behavior and their intent to start another business.

The results: Impermanent sleep problems elicit ADHD-like tendencies and can spur on entrepreneurial intent even among practicing entrepreneurs.

"We were surprised that sleep problems so consistently influenced the entrepreneurial intentions of people who know the challenges of starting a business," says Brian C. Gunia, an associate professor at John Hopkins University's Carey Business School and co-author of the paper.

The paper concludes by saying that we need to carefully weigh the costs and benefits of sleep problems. On the one hand, they may nudge people toward entrepreneurship. On the other, they may undermine entrepreneurial performance if they continue unabated.

Montreal, August 12, 2020 - A new mechanism of blood redistribution that is essential for the proper functioning of the adult retina has just been discovered in vivo by researchers at the University of Montreal Hospital Research Centre (CRCHUM).

Their study was published today in Nature.

"For the first time, we have identified a communication structure between cells that is required to coordinate blood supply in the living retina," said Dr. Adriana Di Polo, a neuroscience professor at Université de Montréal and holder of a Canada Research Chair in glaucoma and age-related neurodegeneration, who supervised the study.

"We already knew that activated retinal areas receive more blood than non-activated ones," she said, "but until now no one understood how this essential blood delivery was finely regulated."

The study was conducted on mice by two members of Di Polo's lab: Dr. Luis Alarcon-Martinez, a postdoctoral fellow, and Deborah Villafranca-Baughman, a PhD student. Both are the first co-authors of this study.

In living animals, as in humans, the retina uses the oxygen and nutrients contained in the blood to fully function. This vital exchange takes place through capillaries, the thinnest blood vessels in all organs of the body. When the blood supply is dramatically reduced or cut off--such as in ischemia or stroke--the retina does not receive the oxygen it needs. In this condition, the cells begin to die and the retina stops working as it should.

Tunnelling between cells

Wrapped around the capillaries are pericytes, cells that have the ability to control the amount of blood passing through a single capillary simply by squeezing and releasing it.

"Using a microscopy technique to visualize vascular changes in living mice, we showed that pericytes project very thin tubes, called inter-pericyte tunnelling nanotubes, to communicate with other pericytes located in distant capillaries," said Alarcon-Martinez. "Through these nanotubes, the pericytes can talk to each other to deliver blood where it is most needed."

Another important feature, added Villafranca-Baughman, is that "the capillaries lose their ability to shuttle blood where it is required when the tunnelling nanotubes are damaged--after an ischemic stroke, for example. The lack of blood supply that follows has a detrimental effect on neurons and the overall tissue function."

The team's findings suggest that microvascular deficits observed in neurodegenerative diseases like strokes, glaucoma, and Alzheimer's disease might result from the loss of tunnelling nanotubes and impaired blood distribution. Strategies that protect these nanostructures should then be beneficial, but remain to be demonstrated.

Picture an airplane that can only climb to one or two altitudes after taking off. That limitation would be similar to the plight facing scientists who seek to avoid instabilities that restrict the path to clean, safe and abundant fusion energy in doughnut-shaped tokamak facilities. Researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and General Atomics (GA) have now published a breakthrough explanation of this tokamak restriction and how it may be overcome.

Toroidal, or doughnut-shaped, tokamaks are prone to intense bursts of heat and particles, called edge localized modes (ELMs). These ELMs can damage the reactor walls and must be controlled to develop reliable fusion power. Fortunately, scientists have learned to tame these ELMs by applying spiraling rippled magnetic fields to the surface of the plasma that fuels fusion reactions. However, the taming of ELMs requires very specific conditions that limit the operational flexibility of tokamak reactors.

ELM suppression

Now, researchers at PPPL and GA have developed a model that, for the first time, accurately reproduces the conditions for ELM suppression in the DIII-D National Fusion Facility that GA operates for DOE. The model predicts the conditions under which ELM suppression should extend over a wider range of operating conditions in the tokamak than previously thought possible. The work presents important predictions for how to optimize the effectiveness of ELM suppression in ITER, the massive international fusion device under construction in the south of France to demonstrate the feasibility of fusion power.

Fusion, the power that drives the sun and stars, combines light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei that makes up 99 percent of the visible universe — to generate massive amounts of energy. Tokamaks are the most widely used devices by scientists seeking to replicate fusion as a renewable, carbon-free source of virtually limitless energy for generating electricity.

PPPL physicists Qiming Hu and Raffi Nazikian are the lead authors of a paper describing the model in Physical Review Letters. They note that under normal conditions the rippled magnetic field can only suppress ELMs for very precise values of the plasma current that produces the magnetic fields that confine the plasma. This creates a problem because tokamak reactors must operate over a wide range of plasma current to explore and optimize the conditions required to generate fusion power.

Modifying magnetic ripples

The authors show how, by modifying the structure of the helical magnetic ripples applied to the plasma, ELMs should be eliminated over a wider range of plasma current with improved generation of fusion power. Hu said he believes the findings could provide ITER with the wide operational flexibility it will need to demonstrate the practicality of fusion energy. “This model could have significant implications for suppressing ELMs in ITER,” he said.

Indeed, “What we have done is to accurately predict when we can achieve ELM suppression over wider ranges of the plasma current,” said Nazikian, who oversees PPPL research on tokamaks. “By trying to understand some strange results we saw on DIII-D, we figured out the key physics that controls the range of ELM suppression that can be achieved using these helically rippled magnetic fields. We then went back and figured out a method that could produce wider operational windows of ELM suppression more routinely in DIII-D and ITER."

Enhanced tokamak operation

The findings open the door to enhanced tokamak operation. “This work describes a path to expand the operational space for controlling edge instability in tokamaks by modifying the structure of the ripples,” said Carlos Paz-Soldan, a GA scientist and a co-author of the paper. “We look forward to testing these predictions with our upgraded field coils that are planned for DIII-D in a few years’ time.”

Returning to the aircraft analogy, “If you could fly at only one or two different altitudes, travel would be very limited,” said PPPL physicist Brian Grierson, a co-author of the paper. “Fixing the restriction would enable the plane to fly over a wide range of altitudes in order to optimize its flight path and fulfill its mission.” In the same way, the present paper lays out an approach that is predicted to expand the capabilities of fusion reactors to operate free from ELMs that can damage the facilities and hinder the development of tokamaks for fusion energy.

When Adelaide glass blower Karen Cunningham made art using diamond and glass she had no idea it would inspire a new kind of hybrid material. Now a consortium of scientists, including from RMIT University and University of Adelaide, is using the technology to make a new class of quantum sensors.

The study published in APL Materials reveals how high-performance diamond sensors can be made using conventional glass fibres.

By embedding micron-scale diamond particles within the cross section of a silicate glass fibre, the team has demonstrated the use of a robust fibre material capable of sensing magnetic fields.

Study lead author and RMIT School of Science's Dr Dongbi Bai said it was an exciting achievement that opened the door to many applications in underwater monitoring, mining and beyond.

"This allows us to make cheap quantum sensor networks that are able to monitor changes in magnetic field, with many useful applications and the answers to questions we haven't thought of yet," she said.

Diamond is one of the front runner technologies for quantum magnetic field sensing, with applications as diverse as brain scanning, navigation and mineral exploration.

But, diamond particles need to be viewed through high-end microscopes that aren't suited for use over an extended period or in the field.

University of Adelaide Deputy Director of the Institute for Photonics and Advanced Sensing, Heike Ebendorff-Heidepriem, said the team had been working to get around this issue for a decade.

"But because diamond burns at high temperatures, we've been limited in the glasses that we can use," she added.

The team has learnt a lot from these so-called 'soft glasses', but these glasses are non-standard and not as good at guiding light as conventional silica fibres, such as those used in the National Broadband Network.

From art to science

This is where glass artist Karen Cunningham comes into the picture. She was making art using nanoparticles to show how light moves through glass and was fascinated by the diamonds that were used by Heike and her colleagues in her research.

"We gave Karen some of our larger diamonds to see how they worked," RMIT School of Science's Professor Brant Gibson, explained.

The diamonds he gave Karen were around one micron in diameter, which is 50 times smaller than the width of a human hair.

"For most of our work, these diamonds are just too big, so we use them mainly for testing," he said.

Incredibly, the diamonds survived Karen's glass blowing, and were part of her exhibition at JamFactory in Adelaide, in 2017.

"For us, it was the lightbulb moment and we knew we could make diamond sensors in more conventional glass fibres," Heike said.

To go from Karen's art to prototype sensors took another three years of testing and fabrication, explained Dr Dongbi Bai.

"It always takes hard work to go from the idea to the product, but I'm so excited by what we've achieved, and even more excited by where this new quantum sensor can take us," she said.

The study of children's interactions with robots was carried out at the Norwegian research fair held in every major city. It is an annual national event where children gain insight into science and what researchers do.

Roger A. Søraaand his research team at the Norwegian University of Science and Technology's (NTNU) Department of Neuromedicine and Movement Science set up three different robots. Søraa studies people's relationship and interaction with robots. Children ages 6-13 participated in the study.

Several countries - in particular Japan where Søraa has had research stays - are looking at how robots can be helpful in elderly care, including helping patients with dementia with certain tasks and remembering things.

"As the current discourse on social robots relates strongly to elderly care, it's interesting to learn what young people think about robots taking care of the elderly, especially in the context of their own older family members," says Søraa.

The researchers recently published the article "Children's Perceptions of Social Robots: a study of the robots Pepper, AV1 and Tessa at Norwegian research fairs" in the journal AI & Society.

Three completely different robots

The children at the research fair got to meet three different robots. One was the robot Pepper, which is a human-like figure that is 120 cm tall and that can do many different tasks.

The autonomous humanoid robot Pepper is an advanced social robot designed primarily as a personal assistant.

Pepper can talk and carry on simple conversations, but in Norway it has challenges with the country's many different dialects, which make it harder for Pepper to learn the Norwegian language.

But it can move around and dance, and can be trained to perceive when someone falls and notify an alarm system, for example. It can provide safety for elderly persons who live alone and who are a bit frail.

Tessa the flower pot

Another robot is simply designed as a flowerpot with eyes. It's called Tessa. How on earth can a flower pot contribute to the care of the elderly?

Tessa is a physical avatar for a home sensor system and dedicated to people with dementia who live alone.

For example, Tessa can learn to recognize the habits of the person it resides with. Through sensors in the refrigerator it could learn that the person in question usually opens the refrigerator door and eats breakfast at 9 a.m. every day. If the fridge is not opened at the usual time, Tessa can remind the person that it is now time to have breakfast. For people with dementia who forget and get confused about time, getting a reminder can be helpful.

"We're now testing this in a dementia project at NTNU, and we're observing that the robot quickly becomes part of the home, along with the normal flower pots. However, the sensor systems are what the relatives appreciate most," says Søraa.

The third robot, AV1, is aimed at children who cannot attend regular school because they are physically unable to, for example because they are sick. The school robot AV1 is shaped like a head with eyes that follow the classroom instruction, and a student can control the robot from home and follow what's going on in class using a mobile app.

Sceptical of Pepper

"Our analysis is based on quantitative survey data from the children about the robots and on qualitative discussions with them at the research fair. By comparing three different types of social robots, we found that their presence can be understood differently based on their function, design and 'aliveness,'" says Søraa.

Pepper was the robot that the kids were most sceptical towards.

"The children's attitudes towards robots were relatively positive, curious and exploratory, but they thought Pepper was a little scary. It probably partly has to do with Pepper being quite big and the same height as some of the kids," Søraa says.

"When the robots have a clear task, like Tessa the flower pot robot and AV1 the teaching robot, they become less intimidating and easier to relate to since we can more readily understand what their task is. Research has also shown that the more a robot looks like a human, the more frightening it becomes," says Søraa. He says the phenomenon can be explained by the Uncanny Valley hypothesis.

The Uncanny Valley phenomenon suggests that acceptance of robots declines the more humanlike they become. We can feel "fooled" when we realize the robot is not a human being, but some other creature.

But in Japan the public is more accepting of humanlike robots.

Tessa best for grandparents

The children were generally positive towards robots as a help with different tasks for older people. But when asked if their own grandparents could benefit from robots, they were more doubtful. Whereas 76 per cent agreed that Pepper could help the elderly, only 60 per cent thought their own grandparents would benefit from Pepper's help.

"This difference could potentially be explained by how the children perceive their own grandparents as relatively fit," Søraa says.

A quote from one of the children was,"I think they [robots] could help my great-grandfather because he is quite forgetful and he lives alone."

"This child thinks that the great-grandparents, but not the grandparents, could benefit from the robot, and it indicates that the child thinks the grandparents are too active to need robot help," says Søraa.

It turned out that the children were most positive about the flower pot robot Tessa as a helpful tool. More than 97 per cent agreed that Tessa could help the elderly and 86 per cent thought that Tessa would be a useful feature in their own grandparents' house as well.

The children liked the idea of a talking flower pot or robotic plant that had the specific task of reminding the elderly of meals and other activities.

Invading cells' private space - prying into their internal functions, decisions and communications - could be a powerful tool that may help researchers develop new immunotherapy treatment for cancer. As reported today in Cell, a research group at the Weizmann Institute of Science has developed a technology that enables them to see inside tens of thousands of individual cells at once in greater details than ever before. The group, headed by Prof. Ido Amit of the Institute's Immunology Department, applied this method to define the immune cells that infiltrate tumors, identifying a new subset of innate immune cells that "collaborate" with cancer. Blocking these inhibitory immune cells in mice greatly enhanced the anti-tumor immune response, killing the cancer.

Amit and his group had previously made significant inroads into seeing into cells when they developed single cell RNA-sequencing - a means of sequencing all of the RNA in thousands of individual cells at once. The new technique, called INs-seq (intracellular staining and sequencing) - developed in Amit's lab in a project led by research students Yonatan Katzenelenbogen, Fadi Sheban, Adam Yalin and Dr. Assaf Weiner - enables scientists to measure, in addition to the RNA, numerous proteins, processes and biochemical pathways occurring inside each of the cells. To do this, they had to develop new methods of getting inside the cell membranes without harming its genetic content. This wealth of "inside information" can help them draw much finer distinctions between different cell subtypes and activities than is possible with existing methods, most of which are able to measure surface proteins only.

In fact, Amit compares those existing methods of cell characterization with buying watermelons: They all appear identical from the outside, even though they can taste completely different when you open them up. Distinguishing between subtypes of cells that seem identical from the outside, such as inhibitory- versus effector-immune cells, may be crucial to when it comes to fighting off cancer.

Although the principal groups of immune cells had been identified many decades ago, there are hundreds of subtypes with many different functions, which haven't been classified. "Specific immune subtypes, for example, may play a role in promoting cancer or enabling it to evade the immune system, provoke tissue destruction by overreacting to a virus or act mistakenly in autoimmune syndromes, attacking our own body. Until now, there was no sufficiently sensitive means of telling these apart from other subtypes that appear identical from the outside," says Sheban.

In order to sort through these different immune functions inside tumors, the Weizmann scientists used their technology to address an issue that researchers had been trying to resolve for decades: Why does the immune system fail to recognize and kill cancer cells, and why does immunotherapy for most tumor types often fail? In searching for an answer, they asked whether cancers might hijack and manipulate particular immune cells to "defend" the cancer cells from the rest of the immune system. "The suspicion that some kind of immune cell might be actively 'collaborating' with cancer is not as strange as it seems," explains Yalin. "Immune responses are often meant to be short-lived, so the immune system has its own mechanisms for shutting them down. Cancers could take advantage of such mechanisms, enhancing the production of the 'shut-down' immune cells, which, in turn, could prevent such immune cells as T lymphocytes that would normally kill them from taking action."

Indeed, the team succeeded in identifying T-cell-blocking immune cells, which belonged to a general group known as myeloid cells - a broad group of innate immune cells that mostly originate in the bone marrow. Although this particular subset of suppressive myeloid cells was new, it was distinguished by a prominent signaling receptor that Amit and his group had seen before, called TREM2. This receptor is critical for the activity of the cells that block the actions of tumor-killing T cells; and normally cells bearing this receptor are crucial for preventing excess tissue damage after injury or calming an inflammatory immune response. But Amit had also come across a version of this receptor in other immune cells involved in Alzheimer's disease, metabolic syndrome and other immune-related pathologies.

The group's next step is to develop an immunotherapy treatment using specific antibodies that target this receptor and could prevent these immune-suppressive cells from supporting the tumor. "Because this receptor is only expressed when there is some type of pathology," says Weiner, "targeting it will not damage healthy cells in the body."

Preliminary evidence for the TREM2 therapeutics was demonstrated by the scientists in mouse models of cancer with genetically ablated TREM2 receptors. In those mice, tumor-killing T cells "came back to life" and attacked the cancer cells; and the tumors shrank significantly. If treatment based on this finding is, in the future, proven effective for human use, it might be administered on its own or in combination with other forms of immunotherapy.

Yeda Research and Development, the technology transfer arm of the Weizmann Institute of Science, is currently working with Amit to develop this immunotherapy antibody for clinical use and there has already been a great deal of interest in INs-seq technology. "Clarifying the mechanisms of autoimmune and neurodegenerative diseases, and answering the question of why the immune system often fails in its fight against cancer or why most patient do not respond to existing immunotherapy - all of these may come down to specific actions of subsets of immune cells. We believe INs-seq may help researchers identify those particular cells and develop new therapies to treat them," says Katzenelenbogen.

A study of five different seafoods has found traces of plastic in every sample tested.

Researchers bought oysters, prawns, squid, crabs and sardines from a market in Australia and analysed them using a newly developed method that identifies and measures five different plastic types simultaneously.

The study - by the University of Exeter and the University of Queensland - found plastic levels of 0.04 milligrams (mg) per gram of tissue in squid, 0.07mg in prawns, 0.1mg in oysters, 0.3mg in crabs and 2.9mg in sardines.

"Considering an average serving, a seafood eater could be exposed to approximately 0.7mg of plastic when ingesting an average serving of oysters or squid, and up to 30mg of plastic when eating sardines, respectively," said lead author Francisca Ribeiro, a QUEX Institute PhD student.

"For comparison, 30mg is the average weight of a grain of rice.

"Our findings show that the amount of plastics present varies greatly among species, and differs between individuals of the same species.

"From the seafood species tested, sardines had the highest plastic content, which was a surprising result."

Co-author Professor Tamara Galloway, of Exeter's Global Systems Institute, said: "We do not fully understand the risks to human health of ingesting plastic, but this new method will make it easier for us to find out."

The researchers bought raw seafood - five wild blue crabs, ten oysters, ten farmed tiger prawns, ten wild squid and ten wild sardines.

They then analysed them for the five different kinds of plastics that can be identified by the new method.

All of the plastics are commonly used in plastic packaging and synthetic textiles and are frequently found in marine litter: polystyrene, polyethylene, polyvinyl chloride, polypropylene and poly(methyl methacrylate).

In the new method, edible tissues are treated with chemicals to dissolve the plastics present in the samples. The resulting solution is analysed using a highly sensitive technique called Pyrolysis Gas Chromatography Mass Spectrometry which can identify the different kinds of plastic in the sample at the same time.

Polyvinyl chloride was found in all samples, while the plastic found in highest concentrations was polyethylene.

Microplastics are very small pieces of plastic that pollute much of the planet, including the sea where they are eaten by marine creatures of all types, from small larvae and planktonic organisms to large mammals.

Studies to date show that microplastics not only enter our diet from seafood, but also from bottled water, sea salt, beer and honey, as well the dust that settles on our meals.

The new testing method is a step towards defining what microplastic levels can be considered harmful and assessing the possible risks of ingesting microplastics in food.

The system that regulates cellular calcium levels duplicated, generating two non-equivalent systems, some one billion years ago before fungi and animals diverged evolutionarily.

The fungal models currently used for the study of mitochondrial calcium regulation are not adequate, as the system they possess is not equivalent to that of animals. Chytrids, a divergent group of fungi, would be the only fungi that possess a system similar to ours.

The study by IRB Barcelona's Comparative Genomics Laboratory has been published in the journal Nature Communications.

Calcium levels regulate multiple processes in cells, ranging from metabolism to division. And these levels are regulated, in turn, by calcium transport into and out of mitochondria, the energy hub of the cell. The regulation of calcium levels is, therefore, a recurring topic of study, with important implications in biomedicine. In this context, fungi are often the model organisms of choice to study this system.

The Comparative Genomics Laboratory of the Institute for Research in Biomedicine (IRB Barcelona), headed by ICREA researcher Toni Gabaldón, and the Barcelona Supercomputing Center (BSC-CNS) has revealed that the transporter that regulates cellular calcium levels duplicated around one billion years ago, giving rise to two transporter subtypes. Of these, only one is present in animals, while most fungi conserve the other. Chytrids--aquatic microscopic organisms--are the only family in the fungal kingdom that has the same transporter subtype as animals. Therefore, the use of the calcium transporter of any other kind of fungus as a model could lead to incoherent observations and incorrect conclusions.

"Determining how cell systems came about and evolved helps us to understand them and to choose appropriate model organisms for research purposes," says Gabaldón.

An extensive computational analysis of more than 1000 organisms

Published in the journal Nature Communications, this study used computational methods to analyse the complete genome of more than 1000 organisms, in order to reconstruct the evolution of the calcium transport machinery in mitochondria. The analysis corroborated the ancestral origin of this mitochondrial transport system, which was already present in the common ancestor of fungi and animals.

Fabiana Perochi's laboratory at the Helmholtz Zentrum in Munich (Germany) carried out experimental tests that confirmed that chytrid proteins perform a function equivalent to that of humans.

The paradox of fungi that do not transport calcium

It had previously been observed that the calcium transporter in fungi acts differently from that in animals and it's even present in organisms that do not transport calcium to mitochondria. This observation was considered a paradox.

"By reconstructing the evolutionary history of these proteins, we have been able to resolve a paradox and identify the true equivalents of the human system in fungi. This finding opens up new avenues for their use as experimental models," concludes Gabaldón.

A new way to check nanomaterial quality enters the 'wild frontier' industry

Nanomaterial quality matters: not least when it's used in the aerospace, automotive and construction industries

A new way to check the quality of nanomaterials like graphene has emerged from a team at the University of Sussex.

Graphene and nanomaterials have been touted as wonder materials, and they are proving invaluable in all sorts of applications, such as in the automotive and aerospace industries, where heavy metals are replaced with lighter but equally strong composite materials. Nanomaterial quality therefore matters a great deal, but standardisation and quality checking have eluded the industry.

The Sussex team have developed a technique that gives detailed information about the size and thickness of graphene particles. It uses a non-destructive, laser-based method for looking at the particles as a whole, and lets them quickly build a detailed picture of the distribution of particles in a given material. Their paper "Raman Metrics for Molybdenum Disulfide and Graphene Enable Statistical Mapping of Nanosheet Populations" is published in the journal 'Chemistry of Materials'.

Dr Matt Large, who led the discovery in the School of Mathematical and Physical Sciences at the University of Sussex, said:

"Standards for measurement are a really critical underpinning of modern economies. It really comes down to one simple question; how do you know you got what you paid for?

"At the moment the graphene industry is a bit of a wild frontier; it's very difficult to compare different products because there is no agreed way of measuring them. That's where studies like ours come in.

"It's really an important issue for any business looking to reap the benefits of graphene (or any other nanomaterial, for that matter) in their products. Often using the wrong material can either have no benefit at all, or even make product performance worse.

"A particular example would be composite materials like graphene-reinforced plastics; if a poor-quality graphene material is used it can cause parts to fail instead of providing the improved strength expected. This can be a big issue for industries such as automotive and aerospace, where there is enormous effort behind replacing heavier metal parts with lighter composite materials (like carbon fibre) that are just as strong. If graphene and other nanomaterials are to play a role in reducing weight and cost then agreed standards are really important."

Aline Amorim Graf is a co-author of the paper in the team at the School of Mathematical and Physical Sciences at the University of Sussex. She said:

"Some manufacturers say they produce graphene but actually - no doubt inadvertently - produce a form of graphite. Some will charge up to £500 per gram.

"The trouble is there's no standardisation. What we've done is to create a new way to measure the quality of nanomaterials like graphene. We use a Raman spectrometer to do this, and have created an algorithm to automate the process. In this way, we can determine the quality, size and thickness of the sample.

"Clearly the quality of graphene really matters. If you're using graphene to strengthen structures, to use in health monitors, to use in supermarket tags, you want to know you're getting the real stuff. But actually purchasers of graphene have no clue as to the quality of what they're buying online. If you're using graphene to strengthen cement, and it turns out it's actually not graphene or is low quality graphene, then that's going to matter."

Professor Alan Dalton, co-Director of the Sussex Programme for Quantum Research and co-author of the paper, said:

"This is truly an important area of research for our team. We believe that our new metric will be of great help to industry, researchers and standards bodies alike who are key-stakeholders in the development of 2D materials towards commercialisation."

The Graphene Council has long called for better standardisation. Terrance Barkan of the Graphene Council has said has written:

"The lack of an agreed global standard for graphene and closely related materials creates a vacuum and lack of trust in the marketplace for industrial scale adoption of graphene materials."

The Sussex team continue their research and are open to checking the quality of graphene on a consultative basis.

Polymers reinforced with ultra-fine strands of carbon fibers epitomize composite materials that are "light as a feather and strong as steel," earning them versatile applications across several industries. Adding materials called carbon nanotubes can further enhance the composites' functionality. But the chemical processes used for incorporating carbon nanotube end up spreading them unevenly on the composites, limiting the strength and other useful qualities that can be ultimately achieved.

In a new study, Texas A&M University researchers have used a natural plant product, called cellulose nanocrystals, to pin and coat carbon nanotubes uniformly onto the carbon-fiber composites. The researchers said their prescribed method is quicker than conventional methods and also allows the designing of carbon-fiber composites from the nanoscale.

The results of the study are published online in the journal American Chemical Society (ACS) Applied Nano Materials.

Composites are built in layers. For example, polymer composites are made of layers of fiber, like carbon fibers or Kevlar, and a polymer matrix. This layered structure is the source of the composites' weakness. Any damage to the layers causes fractures, a process technically known as delamination.

To increase strength and give carbon-fiber composites other desirable qualities, such as electrical and thermal conductivity, carbon nanotubes are often added. However, the chemical processes used for incorporating the carbon nanotubes into these composites often cause the nanoparticles to clump up, reducing the overall benefit of adding these particles.

"The problem with nanoparticles is similar to what happens when you add coarse coffee powder to milk -- the powder agglomerates or sticks to each other," said Dr. Amir Asadi, assistant professor in the Department of Engineering Technology and Industrial Distribution. "To fully take advantage of the carbon nanotubes, they need to be separated from each other first, and then somehow designed to go to a particular location within the carbon-fiber composite."

To facilitate the even distribution of carbon nanotubes, Asadi and his team turned to cellulose nanocrystals, a compound easily obtained from recycled wood pulp. These nanocrystals have segments on their molecules that attract water and other segments that get repelled by water. This unique molecular structure offers the ideal solution to construct composites at the nanoscale, said Asadi.

The hydrophobic part of the cellulose nanocrystals binds to the carbon fibers and anchors them onto the polymer matrix. On the other hand, the water-attractive portions of the nanocrystals help in dispersing the carbon fibers evenly, much like how sugar, which is hydrophilic, dissolves in water uniformly rather than clumping and settling to the bottom of a cup.

For their experiments, the researchers used a commercially available carbon-fiber cloth. To this cloth, they added an aqueous solution of cellulose nanocrystals and carbon nanotubes and then applied strong vibration to mix all of the items together. Finally, they left the material to dry and spread resin on it to gradually form the carbon nanotube coated polymer composite.

Upon examining a sample of the composite using electron microscopy, Asadi and his team observed that the cellulose nanocrystals attached to the tips of the carbon nanotubes, orienting the nanotubes in the same direction. They also found that cellulose nanocrystals increased the composite's resistance to bending by 33% and its inter-laminar strength by 40% based on measuring the mechanical properties of the material under extreme loading.

"In this study, we have taken the approach of designing the composites from the nanoscale using cellulose nanocrystals. This method has allowed us to have more control over the polymer composites' properties that emerge at the macroscale," said Asadi. "We think that our technique is a path forward in scaling up the processing of hybrid composites, which will be useful for a variety of industries, including airline and automobile manufacturing."