Culture

A mollusk and shrimp are two unlikely marine animals that are playing a very important role in engineering. The bodies of both animals illustrate how natural features, like the structures of their bones and shells, can be borrowed to enhance the performance of engineered structures and materials, like bridges and airplanes. This phenomenon, known as biomimetics, is helping advance structural topology research, where the microscale features found in natural systems are being mimicked.

In a recent paper published by researchers at the Georgia Institute of Technology and the Pontifical Catholic University of Rio de Janeiro (Brazil), a new approach to structural topology optimization is outlined that unifies both design and manufacturing to create novel microstructures, with potential applications ranging from enhanced facial implants for cranial reconstruction to improved ways to get materials into space for planetary exploration.

"With traditional structural topology optimization, we use algorithms to determine the ideal layout of a structure - one that maximizes structural efficiency and requires fewer material resources," said Emily Sanders, a Ph.D. student in the School of Civil and Environmental Engineering at Georgia Tech, and co-author of the paper. "Our new research takes that a step further by introducing structural hierarchy, microarchitectures, and spatially-varying mechanical properties to enable different types of functionality like those observed in the cuttlefish and mantis shrimp."

The properties of both animals inspired the new framework for designing hierarchical, spatially-varying microstructures and required the researchers to build on existing technologies used to create 3D-printed structures.

"In our recent work, we've developed technology that includes new algorithms and computations that are the enablers of a hierarchical microstructure," said Glaucio Paulino, Raymond Allen Jones chair and professor in the School of Civil and Environmental Engineering at Georgia Tech, co-author of the paper and recent inductee to the National Academy of Engineering. "We can then input that information into 3D printers and create structures with tremendous amounts of details. After studying the porous, layered cuttlefish bone that has extremely adaptive properties, we've been able to apply that to new structures and materials like the ones shown in our paper."

For Paulino and his team, he hopes this new research will be applied to his earlier work in cranial reconstruction on cancer patients and those who have had massive facial injuries and bone loss.

"Now, we can 3D print craniofacial implants that have been designed using topology optimization and provide the framework for tissue re-growth," said Paulino. "Ideally when combined with the spatially-varying microarchitectures we've recently developed, the implants would more closely mimic the porous nature of the human bone and would promote the growth of the bone itself inside the scaffold. As the bone grows, the scaffold biodegrades, and if everything goes well, in the end the scaffold is gone, and the patient has new bones in the right places."

Design and Manufacturing

As Sanders explains it, there are two aspects being investigated in this paper that advance the study of topology optimization: design and manufacturing. The first goal is to design an optimal macro geometry and at the same time, optimally distribute spatially-varying micro geometries within, in order to meet performance objectives. In this paper, the researchers were looking for maximally stiff parts with limited volume, much like the mantis shrimp hammer claw and they achieved a high level of complexity that mimics nature at both scales.

The second goal is related to the manufacturing needed to create the structures. With additive manufacturing - or 3D printing - researchers can manufacture structures with complex geometries. But with the research team's introduction of spatially-varying microstructures, the printing becomes increasingly difficult.

"The more complex 3D data that we would have to send to the printer is so enormous that it's prohibitive," said Sanders. "So, we had to find a new way to communicate that information to the printer. Now, we communicate only 2D information, embedding the microstructures directly in 2D slices of the structure. At the end, the printer combines the slices to get the structure. It's much more efficient."

"What Emily did with manufacturing closes the loop," said Paulino. "We deliver on the design, mathematics, and algorithms. And we connect topology optimization with the additive manufacturing at both macro and micro levels."

Future Applications

When considering the future of the advancements made to structural topology optimization in this paper, Paulino and Sanders both see applications in biomaterials, as well as magnetic properties designed for space exploration.

For Paulino's work that continues in cranial reconstruction, he envisions interdisciplinary collaborations between engineering, chemistry and biology to develop biocompatible materials and architectures for medical use.

"We're not there yet, but this work is a step in the right direction," said Paulino. "Eventually, we'll be able to print biocompatible materials. This research with spatially-varying microarchitectures should enable the optimal design and manufacturing for biomaterial applications."

Regarding space exploration, the research could impact the creation of synthetic structures and systems with functionality, like magnetic material assemblages that could be actuated on demand by means of applied magnetic fields.

"An important aspect of this work is that it opened up our design space so that we can have spatially-varying properties, which enables us to do things we couldn't before," said Sanders.

Paulino goes on to explain that with space travel, each pound of material sent into space has an enormous cost, so the amount of material and volume brought on space missions is very limited.

"The way I see our manufacturing working in space is you print in place, potentially using printing materials from the foreign planet itself," said Paulino. "You can bring the additive printing capabilities to Mars and print structures with the properties you need when you get there. You print only what you need versus bringing everything you think you might need. In space, you want everything you do to be optimized."

Inspired by animals and how they function in nature, Paulino and his team have evolved topology optimization once again, this time with the new design and manufacturing of spatially-varying, hierarchical structures. And, soon, practical applications in biomedicine and space exploration are sure to follow.

WASHINGTON, April 20, 2021 -- Fiber optic technology is the holy grail of high-speed, long-distance telecommunications. Still, with the continuing exponential growth of internet traffic, researchers are warning of a capacity crunch.

In AVS Quantum Science, by AIP Publishing, researchers from the National Institute of Standards and Technology and the University of Maryland show how quantum-enhanced receivers could play a critical role in addressing this challenge.

The scientists developed a method to enhance receivers based on quantum physics properties to dramatically increase network performance while significantly reducing the error bit rate (EBR) and energy consumption.

Fiber optic technology relies on receivers to detect optical signals and convert them into electrical signals. The conventional detection process, largely as a result of random light fluctuations, produces "shot noise," which decreases detection ability and increases EBR.

To accommodate this problem, signals must continually be amplified as pulsating light becomes weaker along the optic cable, but there is a limit to maintaining adequate amplification when signals become barely perceptible.

Quantum-enhanced receivers that process up to two bits of classical information and can overcome the shot noise have been demonstrated to improve detection accuracy in laboratory environments. In these and other quantum receivers, a separate reference beam with a single-photon detection feedback is used so the reference pulse eventually cancels out the input signal to eliminate the shot noise.

The researchers' enhanced receiver, however, can decode as many as four bits per pulse, because it does a better job in distinguishing among different input states.

To accomplish more efficient detection, they developed a modulation method and implemented a feedback algorithm that takes advantage of the exact times of single photon detection. Still, no single measurement is perfect, but the new "holistically" designed communication system yields increasingly more accurate results on average.

"We studied the theory of communications and the experimental techniques of quantum receivers to come up with a practical telecommunication protocol that takes maximal advantage of the quantum measurement," author Sergey Polyakov said. "With our protocol, because we want the input signal to contain as few photons as possible, we maximize the chance that the reference pulse updates to the right state after the very first photon detection, so at the end of the measurement, the EBR is minimized."

Researchers at Johannes Gutenberg University Mainz (JGU) in Germany and the Institute of Molecular Biology of Barcelona in Spain have discovered how the blood plasma protein fetuin-B binds to the enzyme meprin β and used a computer model to visualize their findings. These results could lead to the development of new drugs to treat serious diseases such as Alzheimer's and cancer. Meprin β releases proteins from cell membranes, thus controlling important physiological functions in the human body. However, a dysregulation of this process can trigger the development of Alzheimer's and cancer. Meprin β is regulated by fetuin-B binding to the enzyme when required, thereby preventing the release of other proteins. Presenting their findings in the journal "Proceedings of the National Academy of Sciences", the researchers are now the first to describe this binding in detail.

The team at Mainz University produced both meprin β and fetuin-B in insect cells and then allowed them to react with one other in a test tube. By means of measurement of enzyme kinetics and biophysical analyses, the researchers determined that this reaction resulted in an exceptionally stable, high-molecular-mass complex. Their colleagues in Barcelona subsequently managed to crystallize the complex and determine its three-dimensional structure using X-ray crystallography. This involved X-rays being fired at the protein crystals, which allowed the atomic structure of the crystals to be calculated from the diffraction of the X-rays. A computer model of the structure was then generated. "Thanks to the model, we can now see exactly how meprin β and fetuin-B bind together," said Professor Walter Stöcker, who conducted the research at JGU together with Dr. Hagen Körschgen and Nele von Wiegen. "This research represents an excellent starting point for gaining a better understanding of diseases such as Alzheimer's and for developing the drugs to combat them." Meprin β is already known to be involved in the formation of so-called beta-amyloid plaques, which are a characteristic feature of the condition. Moreover, people with Alzheimer's disease have relatively little fetuin-B in their blood, which in turn may lead to a lack of regulation of meprin β. "If it is possible to develop a drug that binds to the enzyme and inhibits it in a similar way to fetuin-B, this could be a new way of treating Alzheimer's," concluded Stöcker.

Earthquake early warnings can be delivered successfully using a small network of off-the-shelf smartphones attached to building baseboards, according to a study conducted in Costa Rica last year.

In his presentation at the Seismological Society of America (SSA)'s 2021 Annual Meeting, Ben Brooks of the U.S. Geological Survey said the ASTUTI (Alerta Sismica Temprana Utilizando Teléfonos Inteligentes) network of more than 80 stations performed comparably to scientific-grade warning systems.

During six months' of ASTUTI operation, there were 13 earthquakes that caused noticeable shaking in Costa Rica, including in the city of San Jose where the network was deployed. The system was able to detect and alert on five of these earthquakes, Brooks and his colleagues determined when they "replayed" the seismic events to test their network.

Alerts for the system are triggered when shaking exceeds a certain threshold, equivalent to slightly less than what would be expected for a magnitude 5 earthquake, as measured by the accelerometers that are already built into the phones, Brooks said.

In simulations of the magnitude 7.6 Nicoya earthquake that took place in 2012 in Costa Rica, ASTUTI would have delivered its first alerts on average nine to 13 seconds after the event.

"The performance level over the six months is encouraging," Brooks said. "Cascadia events in the Pacific Northwest are similar to the Costa Rican subduction zone, and latencies for ShakeAlert in Cascadia are about 10 seconds, so it's comparable."

ASTUTI demonstrates the possibilities of lower-cost earthquake early warning for regions that lack the scientific-grade network stations such as those behind ShakeAlert, he noted.

"I would imagine that would be attractive for countries with less resources to dedicate to earthquake early warning" Brooks said, "but the performance is also at a level that I imagine would interest even wealthier countries."

The accelerometers within smartphones are ideal for a low-cost network, Brooks and his colleagues suggested. "If you were to build your own sensors, there's a lot of cost in maintaining them, and the sensors will quickly become obsolete," Brooks said.

By using commercial technology, "we let the big telecommunications companies do the research and development and we just deploy it," he added.

The phones were deployed in the homes of researchers and staff at the Observatorio Vulcanologico y Sismologico de Costa Rica (OVSICORI). The phones were enclosed in a plastic protective box before being mounted to the baseboard with 3M adhesive tape. As a result, the phones sense an earthquake through the filter of the structures, rather than directly as is the case for buried seismometers.

During testing, the system did not issue any false alerts. The researchers' analysis suggests the system could deliver alerts to 15% to 75% of Costa Rica's population in enough time to carry out drop-cover-hold-on responses, if it alerted the entire country after detecting an earthquake.

Country-wide alerting might be a successful strategy for the network, since recent studies show that people tend to be more tolerant than previously suspected of receiving warnings even if they didn't feel shaking, especially if they live in hazard-prone regions such as Costa Rica, said Brooks.

The work was funded by the U.S. Agency for International Development Bureau for Humanitarian Assistance. Next steps for ASTUTI will be to develop an app to make it more user-friendly and to deploy it more widely throughout the country.

Low-cost networks like ASTUTI will be a growing trend in earthquake early warning over the next decade, Brooks predicted. "When your objective is warning, you don't necessarily need the fanciest equipment."

The lack of accountability, poor communication and insufficient planning plaguing the government’s response to the COVID-19 pandemic — especially in its early months — have roots in how the nation responded to 9/11, Hurricane Katrina and the H1N1 swine flu, a new study involving the University of Washington found.

Focusing on the way government agencies assemble and allocate resources – the procurement system – researchers said the successes and shortcomings of responses to other large-scale crises show that a more centralized approach can achieve goals faster and more effectively.

“In the moment of disasters, we prioritize saving lives, but if we also want to achieve other goals, like equity, we need to establish processes and relationships in advance,” said Ben Brunjes, an assistant professor of public policy at the UW and co-author of the study, published April 14 in the Journal of Emergency Management.

In theory, government procurement aims to acquire goods and provide services efficiently, equitably and at the lowest possible cost to the taxpayer. When seeking bids and proposals, agencies are supposed to prioritize spending with businesses owned by women and people of color. During an emergency, however, governments suspend many timelines and rules in the interest of speed.

The government’s approach to the pandemic, especially in the early months when personal protective equipment and medical supplies equipment were the priority, has been criticized as fragmented and politicized. States were generally left to compete on the open market for N95 masks and ventilators; a lack of information and, ultimately, supplies, plagued the Strategic National Stockpile; and even today, the rollout of COVID-19 vaccines has been inconsistent across states.

The highly infectious nature of the coronavirus, and the impact not only on the health care sector but also on most other areas of society, made the pandemic an almost unprecedented emergency for which few countries were prepared, the researchers point out. The United States, with a mostly privatized health care system and three levels of government (local, state and federal) involved in emergency response functions, faced a massive task in protecting the population.

But the Trump administration’s hands-off approach, researchers said, essentially pitted states against each other. Some states had too little and others too much or simply poor-quality supplies, and that opened the door to fraud in the contracting process.

These problems could have been avoided, Brunjes said, if the federal government had recognized and mitigated some of the issues that arose during past crises:

During 9/11, the lack of interagency radio capability thwarted rescue efforts. Emergency responders from different agencies were unable to communicate with each other throughout the 2001 disaster, which led to an effort among law enforcement and other aid agencies nationwide to improve radio systems over the next several years. In the years that followed, new emergency management policies and innovative technologies helped avoid similar problems in subsequent disasters.
The evacuation of millions of people during Hurricane Katrina in 2005 prompted the need for emergency shelters and other services, fast. Several federal agencies purchased temporary beds, trailers and portable school buildings that went unused or were overpriced. The U.S. Government Accountability Office criticized the overall response as vulnerable to “fraud, waste and abuse.” In the aftermath, new laws were passed to make emergency procurement more accountable.
The case most similar to the current pandemic — the H1N1 swine flu in 2009-2010 — showed how the response to COVID-19 might have been different if government had taken the issue seriously and acted quickly. As the H1N1 crisis continued, resources wore thin and coordination across states was stymied. In response, the federal government developed a dashboard to track and share information about critical supplies, aiding in the rapid distribution of vaccines.

In addition to the lessons of better communication and contracting accountability from Hurricane Katrina and 9/11, the government’s experience with H1N1, a smaller-scale pandemic than COVID-19, shows the importance of interagency planning and procurement throughout. That includes the use of existing, issue-specific resources, such as the pandemic guidebook and organizational structure that the federal government developed during H1N1.

“If the previous administration had retained human capital and not gotten rid of the pandemic team, this would have been a lot smoother. There was a lot of knowledge about how to go through this process,” said Brunjes, a former emergency policy analyst for the Department of Homeland Security’s research institute.

The new study was written early in the COVID-19 pandemic, he added, but nothing in the course of events would have changed the researchers’ recommendations. The Biden team has seen the need to take a more central role in communication and management of the response, Brunjes said, and though the administration acted quickly in rolling out a vaccine program, there remain significant equity concerns over who has received the shots. With vaccines alone — all the first and second doses still to be administered, not to mention any booster doses in the future — there should be an even more transparent supply chain and system for determining what agencies need, how much and when.

Co-authors on the study were Sawsan Abutabenjeh of Mississippi State University; Lachezar Anguelov of The Evergreen State College; Ana-Maria Dimand of Boise State University; and Evelyn Rodriguez-Plesa, who worked on the study while completing her doctorate at Florida International University and is the assistant to the city manager of the City of Sunny Isles Beach, Florida.

For more information, contact Brunjes at Brunjes@uw.edu.

Journal

Journal of Emergency Management

DOI

10.5055/jem.0549

The familiar murkiness of waters in the Gulf of Mexico can be off-putting for beachgoers visiting Galveston Island. Runoff from the Mississippi River makes its way to local beaches and causes downstream water to turn opaque and brown. Mud is one factor, and river runoff is another. However, concern tends to ratchet up a notch when pollution enters the river runoff discussion on a national scale, specifically when smaller, navigable intrastate bodies of water push pollution into larger interstate waters often involved in commerce (i.e. the Mississippi River, Great Lakes, Ohio River).

A recently published research analysis in the journal Science, co-authored by Victor Flatt, Dwight Olds Chair in Law at the University of Houston Law Center, demonstrates how the supposed benefits of retracting federal oversight on these transboundary waters and defaulting that responsibility to individual states failed to account for economic and scientific evidence that said otherwise and violated the bounds of justifiable law.

In the article, "A water rule that turns a blind eye to transboundary pollution," Flatt contributed as the sole legal researcher, explaining how the 2020 Navigable Waters Protection Rule, which retracted federal oversight of interstate waters, did so with the overt assumption that state governments would fill in the oversight gap. Not only did the evidence point toward an alternate outcome but the rule's federalism rationale was incorrect, according to the researchers.

"New administrations get to implement new policies, but those policies have to be consistent with statutes, the Constitution and be logical," Flatt said. "The legal phrase is: 'they cannot be arbitrary and capricious.' An administration can only do what is allowed by the law and must be rational and logical. This fails that. This is a policy disagreement, but it is a policy disagreement that is out of the bounds of what is allowed by law."

The cleanliness of larger transboundary rivers falls under the responsibility of the federal government and under the 2015 Clean Water Rule (CWR) enacted during former President Barack Obama's administration. This included small wetlands and streams that could push pollution runoff to these larger rivers that bisect several states. In 2020, under the Navigable Waters Protection Rule (NWPR), the federal regulation of some of those smaller, linked bodies of water was withdrawn, leaving individual states with the responsibility to fill in the gaps. However, many states did not assert control over these waters as assumed by former President Donald Trump's administration, leaving room for pollution to make its way to interstate waters.

"One prominent example is 31 states' challenge to the 2015 CWR in court, arguing that it would impose excessive costs. Inexplicably, the NWPR's economics analysis projected that 14 of these states would now change their position," according to the Science article. As Flatt explains, this assumption was the misstep.

"The Army Corps and EPA said in their analysis that 31 states will move into the breach and help protect the wetlands that the federal government would no longer protect," Flatt said. "But best practices for economic analysis state that you cannot speculate about future state actions. When I looked at this, I found a lot of these states are even prohibited from enacting a rule more stringent than the federal government. Here, the data is flawed."

In March, President Joe Biden's administration proposed a $111 billion investment in water infrastructure. Flatt said that the implementation of the investment will include review of previous policy and research, including information uncovered in the Science article.

Mass extinctions are known as times of global upheaval, causing rapid losses in biodiversity that wipe out entire animal groups. Some of the doomed groups linger on before going extinct, and a team of scientists found these "dead clades walking" (DCW) are more common and long-lasting than expected.

"Dead clades walking are a pattern in the fossil record where some animal groups make it past the extinction event, but they also can't succeed in the aftermath," said Benjamin Barnes, a doctoral student in geosciences at Penn State. "It paints the pictures of a group consigned to an eventual extinction."

The scientists found 70 of the 134 orders of ancient sea-dwelling invertebrates they examined could be identified as DCW in a new statistical analysis of the fossil record.

"What really fascinated us was that over half of all the orders we looked at have this phenomenon and that it can look like many different things," said Barnes, who led a group of graduate students and a postdoctoral researcher on the study. "In some cases, you have a group that has a sudden drop in diversity and lasts for a few more million years before disappearing from the record. But we also found many orders straggled along sometimes for tens or hundreds of millions of years."

The findings, published in the journal Proceedings of the National Academy of Sciences, challenge the view of extinction as a sudden disappearance and suggest that the full impact of mass extinctions lag behind the events themselves longer than previously expected, the scientists said.

"I think it raises questions about how the so-called kill mechanism operates," Barnes said. "We think of mass extinctions as being these selective forces that cause large groups of animals to go extinct, but our results really show there are a lot of instances where it's not so sudden. It raises questions about why that's such a long delay."

Paleontologist David Jablonski first coined the term DCW more than 20 years ago, and since then it has been associated almost exclusively with mass extinctions. Using a wealth of new fossil record data made available over the last two decades, the study found DCW are also common around smaller, more localized background extinction stages, the scientists said.

"Our results suggest that rather than representing a rare, brief fossil pattern in the wake of mass extinction events, DCWs are actually a really diverse phenomenon and that there might be a lot of drivers that produce this pattern in the fossil record," Barnes said. "These DCWs may represent a major macroevolutionary pattern."

The scientists used a statistical technique called a Bayesian change point algorithm to analyze fossil records from the Paleobiology Database, a public record of paleontological data maintained by international scientists.

The method allowed the researchers to search time series data for significant points where the data deviated from the pattern. They were able to identify negative jagged shifts in diversity and rule out that the organism went extinct immediately but instead persisted.

"So you might be looking in the fossil record and you'll find tons of a type of brachiopod," Barnes said. "Each order has a handful of families and dozens of genera within those families. Then you might see a drop in diversity, and the majority of those genera disappear and perhaps there's only one family that continues to survive."

Those survivors can continue in their niche for millions of years, even into the present. But their lack of diversity makes them more susceptible to future environmental challenges or extinction events, the scientists said.

"I think these findings cause you to reexamine how you measure success," Barnes said. "It's quite possible for an animal group not to produce new families and new genera at a rate like it did before, but if it continues to survive for many millions of years, that's still some form of success. I think it raises a lot of questions about what it means to be successful as a fossil organism and what ultimately are the controls of origination."

Researchers at the University of Jyväskylä highlight how the struggles caused by the COVID-19 pandemic can guide us towards an equitable use of our shared environment and a transition towards sustainability.

COVID-19 crisis has emphasized how poorly prepared humanity is to cope with global disasters and to face the new ecological norm under climate change, degraded ecosystems, and biodiversity loss. The final consequences of COVID-19 crisis on sustainability are not yet known. However, this crisis offers a unique opportunity to move towards a greener, more sustainable and equitable society to avoid the destruction of our planet and our own well-being.

We must proactively adapt to the potentially harder times ahead of us aggravated by global environmental changes. "COVID-19 crisis" serves as a global-scale stress-test for our resilience towards an uncertain future, says Visiting Researcher Rémi Duflot from the Department of Biological and Environmental Science at the University of Jyväskylä.

Moving towards a sustainable future path

The actions and objectives for a sustainable transition are already defined by the 2030 Agenda for Sustainable Development by the United Nation. Many alternatives are ready to be implemented through sectorial entry points and can mitigate the social and economic consequences of the COVID-19 pandemic. Now researchers argue that the implementation of a sustainable policy requires a change in societal priorities, shifting from the economic paradigm of growth (of GDP) to human well-being and a healthy environment. To quantify progress towards sustainable well-being, measures of success should account for the multiple dimensions of well-being using a collection of indicators such as Genuine Progress Index and the Sustainable Development Goals.

A sustainable transition, alike an adequate response to a pandemic, requires a cohesive and inclusive society where people adhere to collective actions. Justice in a broad sense should be seen as a precondition to create institutional trust and social security, and thus to encourage citizens' participation in collective projects for sustainability, explains Duflot.

The research emerged as a collaboration within the School of Resource Wisdom community JYU.Wisdom, and was published as a "Note and Comment" in Sustainability Science in April 2021.

WASHINGTON -- Researchers have developed new x-ray optics that can be used to harness extremely fast pulses in a package that is significantly smaller and lighter than conventional devices used to modulate x-rays. The new optics are based on microscopic chip-based devices known as microelectromechanical systems (MEMS).

"Our new ultrafast optics-on-a-chip is poised to enable x-ray research and applications that could have a broad impact on understanding fast-evolving chemical, material and biological processes," said research team leader Jin Wang from the U.S Department of Energy's Argonne National Laboratory. "This could aid in the development of more efficient solar cells and batteries, advanced computer storage materials and devices, and more effective drugs for fighting diseases."

In The Optical Society (OSA) journal Optics Express, the researchers demonstrated their new x-ray optics-on-a-chip device, which measures about 250 micrometers and weighs just 3 micrograms, using the x-ray source at Argonne's Advanced Photon Source synchrotron. The tiny device performed 100 to 1,000 times faster than conventional x-ray optics, which tend to be bulky.

"Although we demonstrated the device in a large x-ray synchrotron facility, when fully developed, it could be used with conventional x-ray generators found in scientific labs or hospitals," said Wang. "The same technology could also be used to develop other devices such as precise dosage delivery systems for radiation therapy or fast x-ray scanners for non-destructive diagnostics."

Capturing fast processes

X-rays can be used to capture very fast processes such as chemical reactions or the quickly changing dynamics of biological molecules. However, this requires an extremely high-speed camera with a fast shutter speed. Because many materials that are opaque to light are transparent to x-rays it can be difficult to improve the speed of shutters effective for x-rays.

To solve this challenge, the research team, consisting of scientists from Argonne's Advanced Photon Source and Center for Nanoscale Materials, turned to MEMS-based devices. "In addition to being used in many of the electronics we use daily, MEMS are also used to manipulate light for high-speed communication," said Wang. "We wanted to find out if MEMS-based photonic devices can perform similar functions for x-rays as they do with visible or infrared light."

In the new work, the researchers show that the extremely small size and weight of their MEMS-based shutter allows it to oscillate at speeds equavilent to about one million revolutions per minute (rpm). The researchers leveraged this high speed and the MEMS material's x-ray diffractive property to create an extremely fast x-ray shutter.

Boosting shutter speed

Using their new optics-on-a-chip with x-rays produced by the Advanced Photon Source, the researchers demonstrated that it could provide a stable shutter speed as fast as one nanosecond with an extremely high on/off contrast. This could be used to extract single x-ray pulses from the source, even if the pulses were only 2.8 nanoseconds apart from each other.

"We show that our new chip-based technology can perform functions not possible with conventional large optics," said Wang. "This can be used to create ultrafast probes for studying fast processes in novel materials."

The researchers are now working to make the devices more versatile and robust so that they can be used continuously over long periods of time. They are also integrating the peripheral systems used with the tiny chip-based MEMS devices into a deployable stand-alone instrument.

People who regularly use psychoactive substances report experiencing a variety of negative impacts since the COVID-19 pandemic began, including increased usage and fear of relapse or overdose, highlighting the need for improved supports and services, including better access to safe supply programs, according to a new CAMH survey published in the International Journal of Drug Policy.

"People who use drugs have been negatively impacted by the pandemic in ways that put them at greater risk for experiencing substance and health-related harms, including overdoses and a decreased ability to mitigate risk behaviours," writes lead author Dr. Farihah Ali. "These findings warrant the need for increased accessibility of safe supply programs, take-home naloxone and drug-testing kits, as well as novel approaches to help ensure they have the necessary tools available to make informed choices and mitigate risk."

Key Survey Findings:

Nearly half of respondents (47 per cent) indicated their substance use had increased during COVID. "I find that I use more because when there's stuff around I tend to get more of it because you don't know when they're gonna get it next or you don't know when there's gonna be more," said one participant. "So you end up buying more, and then when you have more, you end up doing more."

Almost four in ten (38 per cent) respondents said they believed they were more at risk to overdose due to supply disruptions that made drugs more expensive, harder to get and of unknown origin. "I've been using my whole life and I've never overdosed until just a couple weeks ago," said another. The drugs are cut with everything and anything. You never really know what you're getting."

Among those who use syringes and other paraphernalia, nearly half (47 per cent) of respondents said they started re-using or sharing for the first time after COVID began due to reduced hours or COVID restrictions that decreased access to harm reduction or needle exchange programs.

One in fourteen respondents (7 per cent) indicated they had relapsed during COVID.

"One of the potential factors in relapse is all the time spent alone and isolated with all the pandemic restrictions," said survey co-author Dr. Tara Elton-Marshall, Independent Scientist at the CAMH Institute for Mental Health Policy Research. "Using alone itself was a real concern. We know that people who use alone are more likely to die of an overdose, in part because there is nobody there to administer naloxone or call emergency services."

Principal Investigator Dr. Jürgen Rehm, Senior Scientist at the CAMH Institute for Mental Health Policy Research, says that sudden disruptions in the supply of street drugs when the pandemic began were associated with an increase in overdose deaths and other harms. In British Columbia, the number of illicit drug overdose deaths increased by 72 per cent during the first four months of the pandemic between March and July 2020 compared to the year before.

Dr. Rehm believes that the unprecedented circumstances caused by COVID-19 requires unprecedented action, including changes to existing drug laws.

"We need everything from good treatment and harm reduction measures to realizing that we are in an environment where everything is different during COVID and we need different solutions. We need to consider now how to decriminalize drug use. This survey lends strong support for the need for an integrated drug policy strategy including harm reduction."

"People who use drugs feel like they have been a forgotten entity throughout the COVID crisis," said survey co-author Sean LeBlanc. "There was already an overdose crisis in Canada before COVID and it has just gotten worse since then. They are not just numbers. They are all individuals with individual stories and individual losses and individual victories."

LeBlanc, a former opioid addict who has been actively involved in drug use advocacy groups for many years in Ottawa, had a relapse himself just a few weeks after the pandemic began. He says the experience and his successful recovery emphasizes how fragile the recovery experience can be in the face the blunt force of COVID.

"These are people who are at their most vulnerable now," said LeBlanc. "I think about the people who helped me the most when I needed it. That time when someone has the possibility to change, that is sometimes very fleeting. There is so much potential that is being unrealized right now because people aren't getting the help they need when they need it. For me that's the saddest thing right now."

Leesburg, VA, April 20, 2021--An award-winning Scientific Electronic Exhibit to be presented at the ARRS 2021 Virtual Annual Meeting found non-contrast pituitary MRI for central precocious puberty (CPP), growth hormone deficiency (GHD), and short stature (SS) has similar diagnostic yield compared to the standard contrast-enhanced protocol.

"Microadenomas, a common justification for contrast administration, may not influence management in this patient population," wrote first author Jennifer Huang of Vanderbilt University in Nashville, TN, adding "minimal inconvenience would be added for the few patients who would need to return for contrast-enhanced MRI for definitive diagnosis."

Huang and colleagues performed a retrospective review of pediatric pituitary MRI studies from 2010-2019 for CPP, GHD, or SS, then a blinded review of non-contrast images was performed by two subspecialty-trained pediatric neuroradiologists.

Analyzing data from the 448 MRIs obtained for CPP (35%), GHD (49%), or SS (16%), the mean age was 8.2 years (range, 9 months to 17 years). All 448 (100%) scans were performed with gadolinium contrast, while 226 (50%) required sedation. Of the 136 (30%) abnormal studies, there was 71% concordance (n = 97) with the original reports on the blinded review of non-contrast images. Of the 39 discrepancies, 79% (n = 31) were of no clinical significance (e.g., pars intermedia cyst), and 1 was of uncertain significance. The remaining 7 (18%) discrepancies were visible on non-contrast images but required contrast for definitive characterization. Ultimately, 5 were extrasellar masses, and 2 were pituitary stalk abnormalities.

"In a large majority of patients, the shorter non-contrast examination would provide savings in time, anesthesia, gadolinium, and associated costs," the authors of this Magna Cum Laude ARRS Annual Meeting Scientific Electronic Exhibit concluded.

Researchers have found a causal link between caesarean section birth, low intestinal microbiota and peanut sensitivity in infants, and they report the effect is more pronounced in children of Asian descent than others, in a recently published paper in the journal of the American Gastroenterological Association.

"It's important to know what predicts or increases risk of food sensitivities because they predict which infants will go on to develop asthma and other types of allergies," said Anita Kozyrskyj, pediatrics professor in the University of Alberta's Faculty of Medicine & Dentistry and adjunct professor in the School of Public Health.

The research team analysed the gut bacteria of 1,422 infants in the CHILD Cohort Study, by examining fecal samples collected at three or four months of age and again at one year. They identified four typical trajectories for bacterial development, including one in which the infants had persistently low levels of Bacteroides, a type of bacteria known to be critical to immune system development. This profile was most common in babies born by caesarean section.

The infants were given skin prick tests at one and three years of age to assess their reaction to a variety of allergens, including egg, milk and peanut. The babies with low Bacteroides levels were found to have a threefold increase in their risk of developing a peanut sensitivity by age three--and the risk was eight times higher for babies born to mothers of Asian descent.

The team did further statistical analysis to look for what are known as "mediation" or causal effects between the exposure and the outcome. "In this case we observed that there was an association between Asian ethnicity and peanut sensitivity, and then the mediation analysis provided additional evidence for the causal association with caesarean section," explained Kozyrskyj, noting it is the first study to identify this link.

The researchers also observed that the infants with low Bacteroides also had lower levels of sphingolipids, proteins which are key to cell development and signalling in many parts of the body, including the immune system. Gut microbiota are the main source of these proteins. Children who have this deficiency in their immune cells may be more likely to develop food allergies, Kozyrskyj said.

"As the gut microbiota are developing so is the gut's immune system, training the gut to react to pathogens and to be tolerant of the food that we require," she explained.

Half a million Canadian children have a food allergy, while peanut allergy affects about two in 100 and can lead to severe anaphylaxis. Babies who have food allergies are at greater risk to develop asthma, wheezing, eczema and allergic rhinitis later in life, the study authors reported.

The overall rate of allergies is increasing in western countries and is likely linked to environmental factors, said Kozyrskyj, who is principal investigator of the SyMBIOTA (Synergy in Microbiota) laboratory, which studies the impact of maternal and infant antibiotic use, birth mode and breastfeeding on the composition of the intestinal microbiota in infants.

"In China food allergies are uncommon, but those who immigrate to Canada face a higher risk and more severe form of allergic disease," she said. "It's likely related to a change in diet and environment."

The next step for the research is for the results to be replicated in other studies around the world, Kozyrskyj said. She praised her main collaborator Hein Tun, a former post-doctoral fellow at U of A who is now assistant professor of public health at the University of Hong Kong. Their research was funded by the Canadian Institutes of Health Research, Alberta Innovates and the Allergy, Genes, and Environment (AllerGen) Network. Kozyrskyj is a member of the Women and Children's Health Research Institute. Funding partners for the CHILD Cohort Study include the Stollery Children's Hospital Foundation and the Alberta Women's Health Foundation through the Women and Children's Health Research Institute.

Previous research by Kozyrskyj and others has shown that babies born by caesarean section do not get the same beneficial transfer of microbiota from mother to child that infants born through vaginal delivery receive. Studies looking to mitigate this by giving C-section babies probiotics or even swabbing them with their mother's vaginal bacteria have not been as successful as hoped, Kozyrskyj said.

The best path is to avoid caesarean birth unless it is medically necessary. "With this evidence at hand, the parent and the obstetrician might choose a different birth mode," she said.

When disease outbreaks happen, response time in developing and distributing treatments is crucial to saving lives. Unfortunately, developing custom drugs as countermeasures is often a slow and difficult process.

But researchers at the University of Colorado Boulder have created a platform that can develop effective and highly specific peptide nucleic acid therapies for use against any bacteria within just one week. The work is detailed in Nature Communications Biology and could change the way we respond to pandemics and how we approach increasing cases of antibiotic resistance globally.

The Facile Accelerated Specific Therapeutic (FAST) platform was created by Associate Professor Anushree Chatterjee and her team within the Department of Chemical and Biological Engineering. It can quickly produce new antibiotics for any system or disease - from highly adaptive microbial super bugs to radiation poisoning in astronauts - that are specifically designed to selectively target just the bacteria of interest. The paper demonstrates significant growth inhibition and other positive responses in resistant bacteria such as E. coli, which are adapting to current treatments much faster than new drugs can hit the market.

Traditional drug discovery methods usually take 10 or more years and are specific to one bug or another. That is because they are based on identifying molecules from one bacteria that can then be used against other bacteria to promote human health. Unfortunately, evolution over billions of years has resulted in bacteria strains today that are increasingly resistant to this kind of approach - aided in part by recent over prescription of antibiotics by doctors. FAST, on the other hand, can be used for any bug and enables speedy identification and testing of molecules that target new mechanisms in pathogens - getting ahead of that curve.

Kristen Eller, a PhD candidate in the Chatterjee Group, is the first author on the new paper. She said the FAST system utilizes bacteria's genetic makeup to design specific and targeted antibiotics that stop their natural means of producing essential proteins, causing them to die. She added that the platform also provides a unique strategy to deliver these treatments to bacteria that are traditionally hard to target because they reside within our own host cells. To get around this, the platform essentially utilizes bacteria's natural ability to invade our own cells and manipulates it instead to be a carrier of the therapeutic.

"The applications for the real world are immense in that we have created a platform - not just a single therapeutic," she said. "It is adaptive, dynamic and can be altered to target any bacterial species that is a threat while also being modulated to develop antivirals as needed."

Recently, another paper published in PNAS showed the use of the FAST platform to create novel antibiotics against a clinical isolate of carbapenem-resistant E. coli that was found to be resistant to pretty much all antibiotics.

Chatterjee said that last aspect is particularly important as particular strains evolve, change and become more resistant over time. The goal, she said, is to rapidly create tailored treatments specific to the region in question, the person seeking treatment or even the global health situation for example.

"The technology we use to treat these kinds of health issues has to be smart enough to keep up with evolving organisms and also quick enough to respond to real-time crisis," she said. "Within this platform there are multiple steps where you can design and create new drug targets, which is really key."

Chatterjee said the platform could eventually be modified to develop antivirals for treatment of common colds, the flu and most pressingly, COVID-19. For now, her team is working on collecting more data to develop potential COVID-19 treatments and beginning to work towards clinical trials.

"We need to think out of the box when it comes to keeping up with pathogens because they are always advancing and changing," she said. "If we can establish these processes and techniques now, then we will be much better prepared next time there is a pandemic or outbreak."

A new study is the first-ever to identify the genes for creativity in Homo sapiens that distinguish modern humans from chimpanzees and Neanderthals. The research identified 267 genes that are found only in modern humans and likely play an important role in the evolution of the behavioral characteristics that set apart Homo sapiens, including creativity, self-awareness, cooperativeness, and healthy longevity. The study, led by an international and interdisciplinary team of researchers from the American Museum of Natural History and Washington University among other institutions, is published today in the journal Molecular Psychiatry.

"One of the most fundamental questions about human nature is what sparked the explosive emergence of creativity in modern humans in the period just before and after their widespread dispersal from Africa and the related extinction of Neanderthals and other human relatives," said study co-author Ian Tattersall, curator emeritus in the American Museum of Natural History's Division of Anthropology. "Major controversies persist about the basis for human creativity in art and science, as well as about potential differences in cognition, language, and personality that distinguish modern humans from extinct hominids. This new study is the result of a truly pathbreaking use of genomic methodologies to enlighten us about the mechanisms underpinning our uniqueness."

Modern humans demonstrate remarkable creativity compared to their closest living relatives, the great apes (chimpanzees, gorillas, and orangutans and their immediate ancestors), including innovativeness, flexibility, depth of planning, and related cognitive abilities for symbolism and self-awareness that also enable spontaneous generation of narrative art and language. But the genetic basis for the emergence of creativity in modern humans remains a mystery, even after the recovery of full-genome data for both chimpanzees and our extinct close relatives the Neanderthals.

"It has been difficult to identify the genes that led to the emergence of human creativity before now because of the large number of changes in the human genome after it diverged from the common ancestor of humans and chimpanzees around 10 million years ago, as well as uncertainty about the functions of those changes," said Robert Cloninger, a psychiatrist and geneticist at Washington University in St. Louis, and the lead author of the study. "Therefore, we began our research by first identifying the way the genes that influence modern human personality are organized into coordinated systems of learning that have allowed us to adapt flexibly and creatively to changing life conditions."

The team led by Cloninger had previously identified 972 genes that regulate gene expression for human personality, which is comprised of three nearly separate networks for learning and memory. One, for regulating emotional reactivity--emotional drives, habit learning, social attachment, conflict resolution--emerged in monkeys and apes about 40 million years ago. The second, which regulates intentional self-control--self-directedness and cooperation for mutual benefit--emerged a little less than 2 million years ago. A third one, for creative self-awareness, emerged about 100,000 years ago.

In the latest study, the researchers discovered that 267 genes from this larger group are found only in modern humans and not in chimpanzees or Neanderthals. These uniquely human genes code for the self-awareness brain network and also regulate processes that allow Homo sapiens to be creative in narrative art and science, to be more prosocial, and to live longer lives through greater resistance to aging, injury, and illness than the now-extinct hominids they replaced.

Genes regulating emotional reactivity were nearly the same in humans, Neanderthals, and chimps. And Neanderthals were about midway between chimps and Homo sapiens in their genes for self-control and self-awareness.

"We found that the adaptability and well-being of Neanderthals was about 60 to 70 percent of that of Homo sapiens, which means that the difference in fitness between them was large," Cloninger said. "After the more creative, sociable, and physically resilient Homo sapiens migrated out of Africa between 65,000 and 55,000 years ago, they displaced Neanderthals and other hominids, who all became extinct soon after 40,000 years ago."

The genes that distinguish modern humans from Neanderthals and chimpanzees are nearly all regulatory genes made of RNA, not protein-coding genes made of DNA.

"The protein-coding genes of Homo sapiens, Neanderthals, and chimps are nearly all the same, and what distinguishes these species is the regulation of the expression of their protein-coding genes by the genes found only in humans," said co-author Igor Zwir, a computer scientist at Washington University School of Medicine and the University of Granada. "We found that the regulatory genes unique to modern humans were constituents of clusters together with particular protein-coding genes that are overexpressed in the human brain network for self-awareness. The self-awareness network is essential to the physical, mental, and social well-being of humans because it provides the insight to regulate our habits in accord with our goals and values."

The researchers determined that the genes unique to modern humans were selected because of advantages tied to greater creativity, prosocial behavior, and healthy longevity. Living longer, healthier lives and being more prosocial and altruistic allowed Homo sapiens to support their children, grandchildren, and others in their communities throughout their lives in diverse and sometimes harsh conditions. And being more innovative than other hominids allowed humans to adapt more flexibly to unpredictable climatic fluctuations.

"In the bigger picture, this study helps us understand how we can effectively respond to the challenges that modern humans currently face," Tattersall said. "Our behavior is not fixed or determined by our genes. Indeed, human creativity, prosociality, and healthy longevity emerged in the context of the need to adjust rapidly to harsh and diverse conditions and to communicate in large social groups."

Added co-author Coral del Val of the University of Granada, "Now, we face similar challenges to which we must also respond creatively, as we did originally. Unfortunately, when we are exposed to conditions of fear, conflict, inequity, abuse or neglect, our self-awareness is impaired, which diminishes our ability to use our potential for creativity and to achieve well-being. Learning more about the regulatory genes unique to modern humans may help us to promote human well-being as we face these new environmental and social challenges."

It has been a long pursuit to develop super-resolution imaging techniques for Raman microscopy, which has intrinsic advantages of chemical specificity over the fluorescence counterpart. Despite the perceived importance and extensive research efforts, true super-resolution (defined as diffraction-unlimited) Raman imaging of biological systems in the optical far-field remains challenging due to the deficiency in sensitivity for conventional Raman scattering. Consequently, those reported super-resolution vibrational imaging methods have to base on excitation saturating, depleting, or high-order nonlinearity of the Raman transitions. These require extremely intense laser power in order to achieve a moderate resolution improvement (often less than a factor of 2), which inhibits the utility for biological application.

In a new paper published in Light: Science & Application, a team of scientists, led by Professor Wei Min from Columbia University, USA, has developed a novel super-resolution vibrational microscopy harnessing Stimulated Raman Excited Fluorescence (SREF) as an ultrasensitive vibrational contrast. SREF couples the vibrational excitation with fluorescence detection and enables all-far-field Raman spectroscopy with sensitivity down to single-molecule. However, direct coupling of stimulated emission depletion (STED) with SREF imaging fails to achieve super-resolution imaging due to the presence of the anti-stokes fluorescence background, which cannot be depleted by the STED beam.

In this new work, the team devised a frequency-modulation (FM) strategy to remove this broadband background. By temporally modulating the excitation frequency on- and off- the targeted vibrational resonance but still within the background's broad linewidth, they can generate an intensity modulation on the pure vibrational signal (but not on the background). The background-free vibrational signal can be subsequently demodulated by a lock-in detection. Comparing with the typical raw SREF spectrum, the spectrum acquired by FM-SREF represents the pure SREF signal, which enables high-contrast background-free SREF imaging. They further synthesized new isotope-edited SREF dyes to facilitate multicolor FM-SREF biological imaging with sharp vibrational contrast. Two vibrational colors are separated by FM-SREF with minimal cross-talk, which is nearly impossible by conventional fluorescence microscopy. Such chemical specificity of vibrational imaging has unique advantages for multiplexed optical imaging.

Finally, by integrating STED with background-free FM-SREF, they accomplished high-contrast super-resolution vibrational imaging with STED-FM-SREF, whose spatial resolution is only determined by the signal-to-noise. They demonstrated more than two times resolution improvement in biological systems with moderate laser excitation power. With future optimization on the instrumentation and imaging probes, STED-FM-SREF microscopy is envisioned to aid a wide variety of biological applications, with its superb resolution, high sensitivity, unique vibrational contrast, and biocompatible excitation power.