The computer scientists created a family of benchmark quantum circuits with known optimal depths or sizes. In computer design, the smaller the circuit depth, the faster a computation can be completed. Smaller circuits also imply more computation can be packed into the existing quantum computer. Quantum computer designers could use these benchmarks to improve design tools that could then find the best circuit design.

“We believe in the ‘measure, then improve’ methodology,” said lead researcher Jason Cong, a Distinguished Chancellor’s Professor of Computer Science at UCLA Samueli School of Engineering. “Now that we have revealed the large optimality gap, we are on the way to develop better quantum compilation tools, and we hope the entire quantum research community will as well.”

Cong and graduate student Daniel (Bochen) Tan tested their benchmarks in four of the most used quantum compilation tools. A study detailing their research was published in IEEE Transactions on Computers, a peer-reviewed journal.

Tan and Cong have made the benchmarks, named QUEKO, open source and available on the software repository GitHub.

Quantum computers utilize quantum mechanics to perform a great deal of computations simultaneously, which has the potential to make them exponentially faster and more powerful than today’s best supercomputers. But many issues need to be addressed before these devices can move out of the research lab.

For example, due to the sensitive nature of how quantum circuits work, tiny environmental changes, such as small temperature fluctuations, can interfere with quantum computation. When that happens, the quantum circuits are called decoherent — which is to say they have lost the information once encoded in them.

“If we can consistently halve the circuit depth by better layout synthesis, we effectively double the time it takes for a quantum device to become decoherent,” Cong said.

“This compilation research could effectively extend that time, and it would be the equivalent to a huge advancement in experimental physics and electrical engineering,” Cong added. “So we expect these benchmarks to motivate both academia and the industry to develop better layout synthesis tools, which in turn will help drive advances in quantum computing.”

Cong and his colleagues led a similar effort in the early 2000s to optimize integrated circuit design in classical computers. That research effectively pushed two generations of advances in computer processing speeds, using only optimized layout design, which shortened the distance between the transistors that comprise the circuit. This cost-efficient improvement was achieved without any other major investments in technological advances, such as physically shrinking the circuits themselves.

“Quantum processors in existence today are extremely limited by environmental interference, which puts severe restrictions on the length of computations that can be performed,” said Mark Gyure, executive director of the UCLA Center for Quantum Science and Engineering, who was not involved in this study. “That’s why the recent research results from Professor Cong’s group are so important because they have shown that most implementations of quantum circuits to date are likely extremely inefficient and more optimally compiled circuits could enable much longer algorithms to be executed. This could result in today’s processors solving much more interesting problems than previously thought. That’s an extremely important advance for the field and incredibly exciting.”

By tweaking the chemistry of a single polymer, researchers at Texas A&M University and the U.S. Army Combat Capabilities Development Command Army Research Laboratory have created a whole family of synthetic materials that range in texture from ultra-soft to extremely rigid. The researchers said their materials are 3D printable, self-healing, recyclable and they naturally adhere to each other in air or underwater.

Their findings are detailed in the May issue of the journal Advanced Functional Materials.

“We have made an exciting group of materials whose properties can be fine-tuned to get either the softness of rubber or the strength of load-bearing plastics,” said Dr. Svetlana Sukhishvili, professor in the Department of Materials Science and Engineering and a corresponding author on the study. “Their other desirable characteristics, like 3D printability and the ability to self-heal within seconds, make them suited for not just more realistic prosthetics and soft robotics, but also ideal for broad military applications such as agile platforms for air vehicles and futuristic self-healing aircraft wings.”

Synthetic polymers are made up of long strings of repeating molecular motifs, like beads on a chain. In elastomeric polymers, or elastomers, these long chains are lightly crosslinked, giving the materials a rubbery quality. However, these crosslinks can also be used to make the elastomers more rigid by increasing the number of crosslinks.

Although previous studies have manipulated the density of crosslinks to make elastomers stiffer, the resulting change in mechanical strength was generally permanent.

“Crosslinks are like stitches in a piece of cloth, the more stitches you have, the stiffer the material gets and vice versa,” said Sukhishvili. “But instead of having these ‘stitches’ be permanent, we wanted to achieve dynamic and reversible crosslinking so that we can create materials that are recyclable.”

So, the researchers focused their attention on the molecules involved in the crosslinking. First, they chose a parent polymer, called prepolymer, and then chemically studded these prepolymer chains with two types of small crosslinking molecules — furan and maleimide. By increasing the number of these molecules in the prepolymer, they found that they could create materials stiffer. In this way, the hardest material they created was 1,000 times stronger than the softest.

However, these crosslinks are also reversible. Furan and maleimide participate in a type of reversible chemical bonding. Put simply, in this reaction, furan and maleimide pairs can “click” and “unclick” depending on temperature. When the temperature is high enough, these molecules come apart from the polymer chains and the materials soften. At room temperature, the materials harden since the molecules quickly click back together, once again forming crosslinks. Thus, if there is any tear in these materials at ambient temperatures, the researchers showed that furan and maleimide automatically re-click, healing the gap within a few seconds.

The researchers noted that the temperatures at which the crosslinkers dissociate or unclick from the prepolymer chains are relatively the same for different stiffness levels. This property is useful for 3D printing with these materials. Regardless of whether they are soft or hard, the materials can be melted at the same temperature and then used as printing ink.

“By modifying the hardware and processing parameters in a standard 3D printer, we were able to use our materials to print complex 3D objects layer by layer,” said Dr. Frank Gardea, research engineer in the United States Army Research Laboratory and a corresponding author on the study. “The unique advantage of our materials is that the layers that make up the 3D part can be of vastly different stiffness.”

As the 3D part cools to room temperature, he added that the different layers join seamlessly, precluding the need for curing or any other chemical processing. Consequently, the 3D-printed parts can easily be melted using high heat and then recycled as printing ink. The researchers also noted that their materials are reprogrammable. In other words, after being set into one shape, they can be made to change into a different shape using just heat.

In the future, the researchers plan to increase the functionality of their new materials by amplifying its multifaceted properties outlined in the current study.

“Right now, we can easily achieve around 80% self-healing at room temperature, but we would like to reach 100%. Also, we want to make our materials responsive to other stimuli other than temperature, like light,” said Gardea. “Further down the road, we’d like to explore introducing some low-level intelligence so that these materials know to autonomously adapt without needing a user to initiate the process.”

The software, named Peregrine, supports the advanced manufacturing “digital thread” being developed at ORNL that collects and analyzes data through every step of the manufacturing process, from design to feedstock selection to the print build to material testing.

“Capturing that information creates a digital ‘clone’ for each part, providing a trove of data from the raw material to the operational component,” said Vincent Paquit, who leads advanced manufacturing data analytics research as part of ORNL’s Imaging, Signals and Machine Learning group. “We then use that data to qualify the part and to inform future builds across multiple part geometries and with multiple materials, achieving new levels of automation and manufacturing quality assurance.”

The digital thread supports the factory of the future in which custom parts are conceived using computer-aided design, or CAD, and then produced by self-correcting 3D printers via an advanced communications network, with less cost, time, energy and materials compared with conventional production. The concept requires a process control method to ensure that every part rolling off printers is ready to install in essential applications like cars, airplanes, and energy facilities.

To devise a control method for surface-visible defects that would work on multiple printer models, ORNL researchers created a novel convolutional neural network — a computer vision technique that mimics the human brain in quickly analyzing images captured from cameras installed on the printers. The Peregrine software uses a custom algorithm that processes pixel values of images, taking into account the composition of edges, lines, corners and textures. If Peregrine detects an anomaly that may affect the quality of the part, it automatically alerts operators so adjustments can be made.

The software is well suited to powder bed printers. These printers distribute a fine layer of powder over a build plate, with the material then melted and fused using a laser or electron beam. Binder jetting systems rely on a liquid binding agent rather than heat to fuse powdered materials.

The systems print layer by layer, guided by the CAD blueprint, and are popular for the production of metal parts. However, during the printing process, problems such as uneven distribution of the powder or binding agent, spatters, insufficient heat, and some porosities can result in defects at the surface of each layer. Some of those issues may happen in such a very short timeframe that they may go undetected by conventional techniques.

“One of the fundamental challenges for additive manufacturing is that you’re caring about things that occur on length-scales of tens of microns and happening in microseconds, and caring about that for days or even weeks of build time,” said ORNL’s Luke Scime, principal investigator for Peregrine. “Because a flaw can form at any one of those points at any one of those times, it becomes a challenge to understand the process and to qualify a part.”

Peregrine is being tested on multiple printers at ORNL, including as part of the Transformational Challenge Reactor (TCR) Demonstration Program that is pursuing the world’s first additively manufactured nuclear reactor. TCR is leveraging ORNL’s rich history in nuclear science and engineering, materials science and advanced manufacturing to develop a microreactor with newer materials in less time at a lower cost, ensuring the future of this important carbon-free energy source.

“For TCR in particular, you could have a scenario in which the regulator will want detailed data on how a part was manufactured, and we can provide specs with the database built using Peregrine,” Scime said.

“Establishing correlations between these signatures collected during manufacturing and performance during operation will be the most data-rich and informed process for qualifying critical nuclear reactor components,” said Kurt Terrani, TCR program director. “The fact that it may be accomplished during manufacturing to eliminate the long and costly conventional qualification process is the other obvious benefit.”

ORNL researchers stress that by making the Peregrine software machine-agnostic — able to be installed on any powder bed system — printer manufacturers can save development time while offering an improved product to industry. Peregrine produces a common image database that can be transferred to each new machine to train new neural networks quickly, and it runs on a single high-powered laptop or desktop. Standard cameras were used in the research, ranging in most cases from 4 to 20 megapixels and installed so they produce images of the print bed at each layer. The software has been tested successfully on seven powder bed printers at ORNL so far, including electron beam melting, laser powder bed, and binder jetting, as detailed in the journal Additive Manufacturing.

“Anything we can do to help operators and designers know what works and what doesn’t helps with the confidence that the part will be okay for use,” Scime said. “When you have a 3D map of every pixel where the network thinks there is an anomaly and what it thinks the problem is, it opens up a whole world of understanding of the build process.”

As the monitoring system has evolved, Scime said researchers are able to combine the image data with data from other sources such as the printer’s log files, the laser systems and operator notes, allowing parts to be uniquely identified and statistics from all parts tracked and evaluated.

The AI software was developed at the Manufacturing Demonstration Facility at ORNL, a U.S. Department of Energy user facility that works closely with industry to develop, test and refine nearly every type of modern advanced manufacturing technology.

“There’s no place else like the MDF where this machine-agnostic algorithm could have been developed, simply because we have so many machines and so many builds going on all the time in the course of our research,” Scime said. “Access to data is key. Here, we have the ability to place sensors easily and the technicians to make sure everything works and that we’re getting our data. With the variety of scientific expertise available here, it’s been easy to find experts to help with all the challenges involved.”

In other process control work, MDF researchers are developing methods to monitor for defects on the subsurface of builds and to detect porosity that may form in deeper layers, including the use of photodiodes and high-speed cameras.

“We’ve been doing welding for hundreds of years, but additive has only been around for a couple of decades and we don’t know what the problems look like in some cases,” Scime said. “Machine learning techniques allow us to collect and analyze a lot of data quickly. We can then identify those problems and gain the knowledge we need to better understand and prevent anomalies.”

Thanks to research published today in Science Advances by a University of Saskatchewan (USask)-led international research team, this rapid increase in biodiversity — one of two such major events across a 100-million-year timespan 560 to 443 million years ago — is part of a clearer picture emerging of Earth’s ancient oceans and life in them.

“We can see from the trace fossils — tracks, trails, borings, and burrows animals left behind — that this particular environment of the ocean floor, the offshore, served as a ‘crucible’ for life,” said USask paleobiologist Luis Buatois, lead author of the article. “Over the next millions of years, life expanded from this area outwards into deeper waters and inwards into shallower waters.”

The research is the culmination of over 20 years of work from Buatois and the team which examined hundreds of rock formations in locations across every continent.

“Until now, these two events — the Cambrian Explosion and the Great Ordovician Biodiversification Event — have been understood mostly through the study of body fossils — the shells, carapaces and the bones of ancient sea creatures,” said Buatois. “Now we can confidently say that these events are also reflected in the trace fossil record which reveals the work of those soft-bodied creatures whose fleshy tissues rot very quickly and so are only very rarely preserved.”

For the first time, the team has shown evidence of animals actively “engineering” their ecosystem — through the construction of abundant and diverse burrows on the sea floor of the world’s oceans in this ancient time.

“Never underestimate what animals are capable of doing,” said USask paleobiologist Gabriela Mángano, co-author of the paper. “They can modify their physical and chemical environment, excluding other animals or allowing them to flourish by creating new resources. And they were definitely doing all these things in these ancient seas.”

The trace fossil-producing animals’ engineering efforts may have laid the foundation for greater diversity in marine life. The researchers identified a 20-million-year time lag during the Cambrian Explosion (the time when most of the major groups of animals first appear in the fossil record) between diversification in trace fossils and in animal body fossils, suggesting the later animals exploited changes which enabled them to diversify even more.

The research also helps resolve a big question from the geochemical record, which indicated much of the ancient ocean was depleted of oxygen and unsuitable for life. Like oceans today, the Cambrian ocean had certain areas that were full of life, while others lacked the necessary conditions to support it.

“The fact that trace fossil distribution shows that there were spots where life flourished adjacent to others devoid of animal activity all through the early Cambrian period is a strong argument in favor of the idea that zones with enough oxygen to sustain a diversity of animals co-existed with oxygen-depleted waters in deeper areas,” said Mángano. “It’s a situation similar to what happens in modern oceans with oxygen minimum zones in the outer part of the continental shelf and the upper part of the continental slope, but oxygenated ones in shallower water.”

The research could provide new insights from an evolutionary perspective into the importance of extensive rock formations of a similar vintage found in Canada and elsewhere, and help society to prepare for coming challenges.

“Understanding changes that took place early in the history of our planet may help us to face present challenges in modern oceans, particularly with respect to oxygen changes,” said Buatois.

Other members of the team are: USask PhD student Kai Zhou, University of Portsmouth researcher Nic Minter, Senckenberg am Meer institute (Hamburg) researcher Max Wisshak, College of Wooster (Ohio) paleontologist Mark Wilson, and statistician Ricardo Olea of the United States Geological Survey.

The research was funded by grants from Canada’s Natural Sciences and Engineering Research Council awarded to Buatois and Mángano.

The team, which also includes scientists from the University of Maryland, Rensselaer Polytechnic Institute and the IBM Thomas J. Watson Research Center, detailed its work in a paper published today in the peer-reviewed journal Science Advances. Their device shows an increase in brightness of 100 to 1,000 times over conventional tiny, submicron-sized LED designs.

“It’s a new architecture for making LEDs,” said NIST’s Babak Nikoobakht, who conceived the new design. “We use the same materials as in conventional LEDs. The difference in ours is their shape.”

LEDs have existed for decades, but the development of bright LEDs won a Nobel prize and ushered in a new era of lighting. However, even modern LEDs have a limitation that frustrates their designers. Up to a point, feeding an LED more electricity makes it shine more brightly, but soon the brightness drops off, making the LED highly inefficient. Called “efficiency droop” by the industry, the issue stands in the way of LEDs being used in a number of promising applications, from communications technology to killing viruses.

While their novel LED design overcomes efficiency droop, the researchers did not initially set out to solve this problem. Their main goal was to create a microscopic LED for use in very small applications, such as the lab-on-a-chip technology that scientists at NIST and elsewhere are pursuing.

The team experimented with a whole new design for the part of the LED that shines: Unlike the flat, planar design used in conventional LEDs, the researchers built a light source out of long, thin zinc oxide strands they refer to as fins. (Long and thin are relative terms: Each fin is only about 5 micrometers in length, stretching about a tenth of the way across an average human hair’s breadth.) Their fin array looks like a tiny comb that can extend to areas as large as 1 centimeter or more.

“We saw an opportunity in fins, as I thought their elongated shape and large side facets might be able to receive more electrical current,” Nikoobakht said. “At first we just wanted to measure how much the new design could take. We started increasing the current and figured we’d drive it until it burned out, but it just kept getting brighter.”

Their novel design shone brilliantly in wavelengths straddling the border between violet and ultraviolet, generating about 100 to 1,000 times as much power as typical tiny LEDs do. Nikoobakht characterizes the result as a significant fundamental discovery.

“A typical LED of less than a square micrometer in area shines with about 22 nanowatts of power, but this one can produce up to 20 microwatts,” he said. “It suggests the design can overcome efficiency droop in LEDs for making brighter light sources.”

“It’s one of the most efficient solutions I have seen,” said Grigory Simin, a professor of electrical engineering at the University of South Carolina who was not involved in the project. “The community has been working for years to improve LED efficiency, and other approaches often have technical issues when applied to submicrometer wavelength LEDs. This approach does the job well.”

The team made another surprising discovery as they increased the current. While the LED shone in a range of wavelengths at first, its comparatively broad emission eventually narrowed to two wavelengths of intense violet color. The explanation grew clear: Their tiny LED had become a tiny laser.

“Converting an LED into a laser takes a large effort. It usually requires coupling a LED to a resonance cavity that lets the light bounce around to make a laser,” Nikoobakht said. “It appears that the fin design can do the whole job on its own, without needing to add another cavity.”

A tiny laser would be critical for chip-scale applications not only for chemical sensing, but also in next-generation hand-held communications products, high-definition displays and disinfection.

“It’s got a lot of potential for being an important building block,” Nikoobakht said. “While this isn’t the smallest laser people have made, it’s a very bright one. The absence of efficiency droop could make it useful.”

The research was supported in part by the U.S. Army Cooperative Research Agreement.

Massive marine ecosystems like the Great Barrier Reef aren’t just a vibrant home to fish, corals and other creatures, they are also an important source of people’s food, livelihoods and recreation.

The new study suggests the way people are managed when undertaking various activities within the marine park — like fishing, boating, and scientific research — could serve as an exemplary model for sustainably managing other ecosystems that humans use.

“There is plenty of evidence to suggest that the Great Barrier Reef is managed at appropriate scales within its boundaries,” said lead author Professor Graeme Cumming, incoming Director of the ARC Centre of Excellence for Coral Reef Studies.

The reef served as a case study for mapping and measuring different scale matches between people and ecosystems. Prof Cumming explains the concept of scale matches using a backyard garden as an example of an ecosystem.

“For a house with a garden, you already have permission to manage that garden — to mow the lawn and trim the trees inside your fences. To look after all the parts of it. That’s a scale match,” Prof Cumming said.

He says being able to manage only a flower bed within the garden is a small-scale match. “If you only have permission to manage the flower bed in your garden, you can manage the flowers, but your lawn and trees become unkempt. The weeds and pests affecting the flowers may come from an adjacent part of the garden, which you’d then have no control over,” he said.

The Great Barrier Reef Marine Park Authority (GBRMPA) manages the entire marine park. Some permits, such as permission to access areas by boat as part of a commercial operation, may cover most of the park.

GBRMPA also manages smaller scale permits within the marine park boundaries — small-scale matches that work best for activities like commercial tourism, lobster fisheries or the installation of certain structures like jetties or moorings.

The study found the permits issued for human activities generally occurred at larger scales than the particular individual marine features of interest, such as reefs or islands.

“The finding that people are managed at a broader scale than ecological variation suggests a general principle for permitting and management,” Prof Cumming said. “In essence, people like to have choices about where they go and how they respond to change. This means that they prefer to operate at a broader spatial scale than the ecological features they are interested in, rather than the same scale.”

The findings suggest this approach to managing people at broader rather than finer scales may be more effective. For small protected areas, increasing the size of the permissible area may even be critical.

However, GBRMPA can’t manage the ecosystem’s biggest impact, which lies outside park boundaries: climate change.

“Broad scale problems, like climate change, can only be managed with broad scale solutions, like global action,” Prof Cumming said. “This is a scale mismatch because these impacts come from well outside the marine park boundaries.”

GBRMPA also don’t have control over what happens on the land directly adjacent to the reef. Not being able to stop pollutants and pesticides in storm water reaching the reef is another scale mismatch.

Prof Cumming says comparing the results of this study to similar data from other marine parks, including those that are recognised as dysfunctional, will help determine if the management of the Great Barrier Reef Marine Park is unusual or typical.

“This study does not offer a direct solution for management,” Prof Cumming said. “But it provides a new approach that extends our toolbox for diagnosing social-ecological scale mismatches and responding to them.”

The short form of deoxyribonucleic acid is widely understood, but there are millions more acronyms (like WTF: water-soluble thiourea-formaldehyde) that are making science less useful and more complex for society, according to a new paper released by Australian researchers.

Queensland University of Technology (QUT) Professor Adrian Barnett and Dr Zoe Doubleday from the University of South Australia (UniSA) have analysed 24 million scientific article titles and 18 million abstracts between 1950 and 2019, looking for trends in acronym use.

Despite repeated calls for scientists to reduce their use of acronyms and jargon in journal papers, the advice has been largely ignored, their findings show in a paper published in eLife.

Many of the 1.1 million unique acronyms identified in the past 70 years are causing confusion, ambiguity and misunderstanding, making science less accessible, the researchers say.

“For example, the acronym UA has 18 different meanings in medicine, and six of the 20 most widely used acronyms have multiple common meanings in health and medical literature,” according to Dr Zoe Doubleday.

“When I look at the top 20 scientific acronyms of all time, it shocks me that I recognise only about half. We have a real problem here.”

DNA is universally recognised, but the second most popular acronym CI (confidence interval) could easily be confused for chief investigator, cubic inch or common interface. Likewise, US (United States/ultrasound/urinary system) and HR (heart rate/hazard ratio) often trip people up.

Prof Barnett says the use of acronyms in titles has more than trebled since 1950 and increased 10-fold in scientific abstracts in the same period.

“Strikingly, out of the 1.1 million acronyms analysed, we found that two per cent (about 2,000) were used more than 10,000 times,” he says. “Even when the 100 most popular acronyms were removed, there was still a clear increase in acronym use over time.”

Entrenched writing styles in science are difficult to shift and excessive acronym use points to a broader communication problem in science, Dr Doubleday says, but journals could help stem the trend by restricting the number of acronyms used in a paper.

“In the future it might be possible — software permitting — for journals to offer two versions of the same paper, one with acronyms and one without, so that the reader can select the version they prefer.”

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A team of scientists led by KOH Gou Young at the Center for Vascular Research, within the Institute for Basic Science (IBS, South Korea) have identified new subsets of gut connective cells, which are crucial for lymphatic growth. Their new findings have been reported in the journal Nature Communications.

The walls of the small intestine are covered with fingerlike projections, called villi. Lining these villi, heterogeneous populations of epithelial, immune, vascular, connective and even neural cells co-exist and help the digestive process. Lacteals and blood capillaries run inside the villi and take in different food molecules. The gut environment needs to cope with water secretion and reabsorption (osmotic stress), as well as the repetitive muscular activity that moves food through the intestine. How all these complex mechanisms are harmonized is still a mystery.

The research team was able to place a new piece towards completing this mysterious puzzle. The researchers found that the regulatory proteins YAP/TAZ in villi’s connective cells, the intestinal stromal cells, play a role in the growth of nearby lacteals. In mice with an abnormal hyperactivation of YAP/TAZ, the team observed atypical sprouting of lacteals and impaired dietary fat uptake.

“The lacteals in these mice looked like tridents, which is very intriguing, since we did not manipulate the lacteals themselves, but the surrounding cells,” says HONG Seon Pyo, first co-author of this study.

The researchers took a step further and discovered that intestinal stromal cells belong to several subtypes, with distinct gene expression and localizations within the villi. Among these subsets, three newly identified populations secrete VEGF-C — an essential molecule for lymphatic growth — upon YAP/TAZ activation. YANG Myung Jin, first co-author of this study, explains, “We were very surprised to see such heterogeneity in a cell population that was considered homogeneous.”

Lastly, researchers showed that mechanical force and osmotic stress regulate YAP/TAZ activity in stromal cells. In summary, mechanical stimulation activates YAP/TAZ in the intestinal stromal cells, which in turn release VEGF-C and can account for lacteal growth. CHO Hyunsoo, first co-author of this study notes, “This result implies a crucial link between the physiology of intestinal environment and biological interactions between cell types.”

“We are interested in investigating how each newly identified cell type works in healthy and diseased conditions,” adds Koh.

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