Small, mighty robots mimic the powerful punch of mantis shrimp

Robot models the mechanics of the strongest punch in the animal kingdom

Peer-Reviewed Publication

U.S. ARMY RESEARCH LABORATORY

 

IMAGE: RESEARCHERS WITH ARMY FUNDING BUILD A ROBOT THAT MIMICS THE STRONG PUNCH OF A MANTIS SHRIMP. view more 

CREDIT: SECOND BAY STUDIOS AND ROY CALDWELL/HARVARD SEAS

RESEARCH TRIANGLE PARK, N.C. -- Modeling the mechanics of the strongest punch in the animal kingdom, researchers with U.S. Army funding built a robot that mimics the movement of the mantis shrimp. These pugnacious crustaceans could pave the way for small, but mighty robotic devices for the military.

Researchers at Harvard University and Duke University, published their work in Proceedings of the National Academy of Sciences. They shed light on the biology of mantis shrimp, whose club-like appendages accelerate faster than a bullet out of a gun. Just one strike can knock the arm off a crab or break through a snail shell. These crustaceans have even taken on an octopus and won.

“The idea of a loaded spring released by a latch is a staple in mechanical design, but the research team cleverly observed that engineers have yet to achieve the same performance out of a Latch-Mediated Spring Actuator that we find in nature,” said Dr. Dean Culver program manager, U.S. Army Combat Capabilities Development Command Army Research Laboratory. “By more closely mimicking the geometry of a mantis shrimp's physiology, the team was able to exceed accelerations produced by limbs in other robotic devices by more than tenfold.”

How mantis shrimp produce these deadly, ultra-fast movements has long fascinated biologists. Recent advancements in high-speed imaging make it possible to see and measure these strikes, but some of the mechanics have not been well understood.

Many small organisms, including frogs, chameleons, and even some kinds of plants, produce ultra-fast movements by storing elastic energy and rapidly releasing it through a latching mechanism, like a mouse trap. In mantis shrimp, two small structures embedded in the tendons of the muscles called sclerites act as the appendage’s latch. In a typical spring-loaded mechanism, once the physical latch is removed, the spring would immediately release the stored energy, but when the sclerites unlatch in a mantis shrimp appendage, there is a short but noticeable delay.

“When you look at the striking process on an ultra-high-speed camera, there is a time delay between when the sclerites release and the appendage fires,” said Nak-seung Hyun, a postdoctoral fellow at Harvard John A. Paulson School of Engineering and Applied Sciences and co-first author of the paper. “It is as if a mouse triggered a mouse trap, but instead of it snapping right away, there was a noticeable delay before it snapped. There is obviously another mechanism holding the appendage in place, but no one has been able to analytically understand how the other mechanism works.”

Biologists have hypothesized that while the sclerites initiate unlatching, the geometry of the appendage itself acts as a secondary latch, controlling the movement of the arm while it continues to store energy. But this theory had not yet been tested.

The research team tested this hypothesis first by studying the linkage mechanics of the system, then building a physical, robotic model. Once they had the robot, the team was able to develop a mathematical model of the movement. The researchers mapped four distinct phases of the mantis strike, starting with the latched sclerites and ending with the actual strike of the appendage. They found that, indeed, after the sclerites unlatch, geometry of the mechanism takes over, holding the appendage in place until it reaches an over-centering point and then the latch releases.

“This process controls the release of stored elastic energy and actually enhances the mechanical output of the system,” said Emma Steinhardt, a graduate student at Harvard John A. Paulson School of Engineering and Applied Sciences and first author of the paper. “The geometric latching process reveals how organisms generate extremely high acceleration in these short duration movements, like punches.”

The device is faster than any similar devices at the same scale to date.

“This study exemplifies how interdisciplinary collaborations can yield discoveries for multiple fields,” said co-author Dr. Sheila Patek, professor of biology at Duke University. “The process of building a physical model and developing the mathematical model led us to revisit our understanding of mantis shrimp strike mechanics and, more broadly, to discover how organisms and synthetic systems can use geometry to control extreme energy flow during ultra-fast, repeated-use, movements.”

This approach of combining physical and analytical models could help biologists understand and roboticists mimic some of nature’s other extraordinary feats, such as how trap jaw ants snap their jaws so quickly or how frogs propel themselves so high.

“Actuator architecture like this offers impressive capabilities to small and lightweight mechanisms that need to deliver impulsive forces for the Army,” Culver said. “But I think there's a broader takeaway here - something the engineering community and defense research can keep in mind. We're not done learning about mechanical performance from nature and biological systems. Things we take for granted, like a simple sprung actuator, are still ripe for further investigation at many scales."

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As the Army’s foundational research laboratory, ARL is operationalizing science to achieve transformational overmatch. Through collaboration across the command’s core technical competencies, DEVCOM leads in the discovery, development and delivery of the technology-based capabilities required to make Soldiers more successful at winning the nation’s wars and come home safely. DEVCOM Army Research Laboratory is an element of the U.S. Army Combat Capabilities Development Command. DEVCOM is a major subordinate command of the Army Futures Command.

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2026833118 

ARTICLE TITLE

A physical model of mantis shrimp for exploring the dynamics of ultrafast systems

ARTICLE PUBLICATION DATE

17-Aug-2021

 

Regular exercise may lower risk of developing anxiety by almost 60%

The findings of a study published with Frontiers suggests that those who engage in regular exercise may lower their risk of developing anxiety by almost 60%.

Peer-Reviewed Publication

FRONTIERS

A quick online search for ways to improve our mental health will often come up with a myriad of different results. However, one of the most common suggestions put forward as a step to achieving wellness – and preventing future issues – is doing some physical exercise, whether it be a walk or playing a team sport.

Anxiety disorders – which typically develop early in a person’s life – are estimated to affect approximately 10% of the world’s population and has been found to be twice as common in women compared to men. And while exercise is put forward as a promising strategy for the treatment of anxiety, little is known about the impact of exercise dose, intensity or physical fitness level on the risk of developing anxiety disorders.

To help answer this question, researchers in Sweden have published a study in Frontiers in Psychiatry to show that those who took part in the world’s largest long-distance cross-country ski race (Vasaloppet) between 1989 and 2010 had a “significantly lower risk” of developing anxiety compared to non-skiers during the same period.

The study is based on data from almost 400,000 people in one of the largest ever population-wide epidemiology studies across both sexes.

Surprising finding among female skiers

“We found that the group with a more physically active lifestyle had an almost 60% lower risk of developing anxiety disorders over a follow-up period of up to 21 years,” said first author of the paper, Martine Svensson, and her colleague and principal investigator, Tomas Deierborg, of the Department of Experimental Medical Science at Lund University, Sweden.

“This association between a physically active lifestyle and a lower risk of anxiety was seen in both men and women.”

However, the authors found a noticeable difference in exercise performance level and the risk of developing anxiety between male and female skiers.

While a male skier’s physical performance did not appear to affect the risk of developing anxiety, the highest performing group of female skiers had almost the double risk of developing anxiety disorders compared to the group which was physically active at a lower performance level.

“Importantly,” they said, “the total risk of getting anxiety among high-performing women was still lower compared to the more physically inactive women in the general population”.

These findings cover relatively uncharted territory for scientific research, according to the researchers, as most previous studies focused on depression or mental illness as opposed to specifically diagnosed anxiety disorders. Furthermore, some of the largest studies looking at this topic only included men, were much smaller in sample size, and had either limited or no follow-up data to track the long-term effects of physical activity on mental health.

Next steps for research

The surprising discovery of an association between physical performance and the risk for anxiety disorders in women also emphasized the scientific importance of these findings for follow-up research.

“Our results suggest that the relation between symptoms of anxiety and exercise behavior may not be linear,” Svensson said.

“Exercise behaviors and anxiety symptoms are likely to be affected by genetics, psychological factors, and personality traits, confounders that were not possible to investigate in our cohort. Studies investigating the driving factors behind these differences between men and women when it comes to extreme exercise behaviors and how it affects the development of anxiety are needed.”

They added that randomized intervention trials, as well as long-term objective measurements of physical activity in prospective studies, are also needed to assess the validity and causality of the association they reported. But does this mean that skiing in particular can play an important role in keeping anxiety at bay, as opposed to any other form of exercise? Not so, Svensson and Deierborg said, given that previous studies have also shown the benefits of keeping fit on our mental health.

“We think this cohort of cross-country skiers is a good proxy for an active lifestyle, but there could also be a component of being more outdoors among skiers,” they said.

“Studies focusing on specific sports may find slightly different results and magnitudes of the associations, but this is most likely due to other important factors that affect mental health and which you cannot easily control in research analysis.”

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JOURNAL

Frontiers in Psychiatry

DOI

10.3389/fpsyt.2021.714014 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Physical activity is associated with lower long-term incidence of anxiety in a population-based, large-scale study

ARTICLE PUBLICATION DATE

10-Sep-2021

COI STATEMENT

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

 

Smart dental implants

Geelsu Hwang of the University of Pennsylvania and colleagues are developing a smart dental implant that resists bacterial growth and generates its own electricity through chewing and brushing to power a tissue-rejuvenating light.

Peer-Reviewed Publication

UNIVERSITY OF PENNSYLVANIA

More than 3 million people in America have dental implants, used to replace a tooth lost to decay, gum disease, or injury. Implants represent a leap of progress over dentures or bridges, fitting much more securely and designed to last 20 years or more.

But often implants fall short of that expectation, instead needing replacement in five to 10 years due to local inflammation or gum disease, necessitating a repeat of a costly and invasive procedure for patients.

“We wanted to address this issue, and so we came up with an innovative new implant,” says Geelsu Hwang, an assistant professor in the University of Pennsylvania School of Dental Medicine, who has a background in engineering that he brings to his research on oral health issues.

The novel implant would implement two key technologies, Hwang says. One is a nanoparticle-infused material that resists bacterial colonization. And the second is an embedded light source to conduct phototherapy, powered by the natural motions of the mouth, such as chewing or toothbrushing. In a paper in the journal ACS Applied Materials & Interfaces and a 2020 paper in the journal Advanced Healthcare Materials, Hwang and colleagues lay out their platform, which could one day be integrated not only into dental implants but other technologies, such as joint replacements, as well.

“Phototherapy can address a diverse set of health issues,” says Hwang. “But once a biomaterial is implanted, it’s not practical to replace or recharge a battery. We are using a piezoelectric material, which can generate electrical power from natural oral motions to supply a light that can conduct phototherapy, and we find that it can successfully protect gingival tissue from bacterial challenge.”

In the paper, the material the researchers explored was barium titanate (BTO), which has piezoelectric properties that are leveraged in applications such as capacitators and transistors, but has not yet been explored as a foundation for anti-infectious implantable biomaterials. To test its potential as the foundation for a dental implant, the team first used discs embedded with nanoparticles of BTO and exposed them to Streptococcus mutans, a primary component of the bacterial biofilm responsible for tooth decay commonly known as dental plaque. They found that the discs resisted biofilm formation in a dose-dependent manner. Discs with higher concentrations of BTO were better at preventing biofilms from binding.

While earlier studies had suggested that BTO might kill bacteria outright using reactive oxygen species generated by light-catalyzed or electric polarization reactions, Hwang and colleagues did not find this to be the case due to the short-lived efficacy and off-target effects of these approaches. Instead, the material generates enhanced negative surface charge that repels the negatively charged cell walls of bacteria. It’s likely that this repulsion effect would be long-lasting, the researchers say.

“We wanted an implant material that could resist bacterial growth for a long time because bacterial challenges are not a one-time threat,” Hwang says.

The power-generating property of the material was sustained and in tests over time the material did not leach. It also demonstrated a level of mechanical strength comparable to other materials used in dental applications.

Finally, the material did not harm normal gingival tissue in the researchers’ experiments, supporting the idea that this could be used without ill effect in the mouth.

The technology is a finalist in the Science Center’s research accelerator program, the QED Proof-of-Concept program. As one of 12 finalists, Hwang and colleagues will receive guidance from experts in commercialization. If the project advances to be one of three finalists, the group has the potential to receive up to $200,000 in funding.

In future work, the team hopes to continue to refine the “smart” dental implant system, testing new material types and perhaps even using assymetric properties on each side of the implant components, one that encourages tissue integration on the side facing the gums and one that resists bacterial formation on the side facing the rest of the mouth.

“We hope to further develop the implant system and eventually see it commercialized so it can be used in the dental field,” Hwang says.

Geelsu Hwang is an assistant professor in the Division of Restorative Dentistry and Department of Preventive and Restorative Sciences in the University of Pennsylvania’s School of Dental Medicine.

Hwang’s coauthors on the paper were Penn Dental Medicine’s Atul Dhall and Yu Zhang and Temple University’s Sayemul Islam, Moonchul Park, and Albert Kim.

The research was supported by the National Institutes for Dental and Craniofacial Research(Grant DE027970) and the National Science Foundation (Grant 2029077). It was carried out in part at Penn’s Singh Center for Nanotechnology, which is supported by the NSF National Nanotechnology Coordinated Infrastructure Program under Grant NNCI-1542153.

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DOI

10.1021/acsami.1c11791 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Bimodal Nanocomposite Platform with Antibiofilm and Self-Powering Functionalities for Biomedical Applications

ARTICLE PUBLICATION DATE

18-Aug-2021

Preventing the long-term effects of traumatic brain injury

New study points to a potential new treatment that could prevent chronic complications

Peer-Reviewed Publication

GLADSTONE INSTITUTES

 

IMAGE: A TEAM OF RESEARCHERS LED BY JEANNE PAZ (LEFT) AND STEPHANIE HOLDEN (RIGHT) POINTS TO A POTENTIAL NEW TREATMENT THAT COULD PREVENT THE LONG-TERM EFFECTS OF TRAUMATIC BRAIN INJURY. view more 

CREDIT: PHOTO: MICHAEL SHORT/GLADSTONE INSTITUTES

SAN FRANCISCO, CA—September 9, 2021—You’ve been in a car accident and sustained a head injury. You recovered, but years later you begin having difficulty sleeping. You also become very sensitive to noise and bright lights, and find it hard to carry out your daily activities, or perform well at your job.

This is a common situation after a traumatic brain injury—many people experience bad side effects months or years later. These long-term effects can last a few days or the rest of a person’s life.

“No therapies currently exist to prevent the disabilities that can develop after a brain trauma,” says Jeanne Paz, PhD, associate investigator at Gladstone Institutes. “So, understanding how the traumatic brain injury affects the brain, especially in the long term, is a really important gap in research that could help develop new and better treatment options.”

In a new study published in the journal Science, Paz and her team helped close that gap. They identified a specific molecule in a part of the brain called the thalamus that plays a key role in secondary effects of brain injury, such as sleep disruption, epileptic activity, and inflammation. In collaboration with scientists at Annexon Biosciences, a clinical-stage biopharmaceutical company, they also showed that an antibody treatment could prevent the development of these negative outcomes.

A Vulnerable Brain Region

Traumatic brain injuries, which range from a mild concussion to a severe injury, can be the result of a fall, sports injury, gunshot injury, blow to the head, explosion, or domestic violence. Often, soldiers returning from war also suffer head injuries, which commonly lead to the development of epilepsy. Traumatic brain injury affects 69 million people around the world annually, and is the leading cause of death in children and a major source of disability in adults.

“These injuries are frequent and can happen to anyone,” says Paz, who is also an associate professor of neurology at UC San Francisco (UCSF) and a member of the Kavli Institute for Fundamental Neuroscience. “The goal of our study was to understand how the brain changes after traumatic brain injuries and how those changes can lead to chronic problems, such as the development of epilepsy, sleep disruption, and difficulty with sensory processing.”

To do so, Paz and her team recorded the activity of different cells and circuits in the brain of mice after brain injury. The researchers monitored the mice continually and wirelessly, meaning the mice could go about their normal activities without being disrupted.

“We collected so much data, from the time of injury and over the next several months, that it actually crashed our computers,” says Paz. “But it was important to capture all the different stages of sleep and wakefulness to get the whole picture.”

During a trauma to the head, the region of the brain called the cerebral cortex is often the primary site of injury, because it sits directly beneath the skull.

But at later time points, the researchers discovered that another region—the thalamus—was even more disrupted than the cortex. In particular, they found that a molecule called C1q was present at abnormally high levels in the thalamus for months after the initial injury, and these high levels were associated with inflammation, dysfunctional brain circuits, and the death of neurons.

“The thalamus seems particularly vulnerable, even after a mild traumatic brain injury,” says Stephanie Holden, PhD, first author of the study and former graduate student in Paz’s lab at Gladstone. “This doesn’t mean the cortex isn’t affected, but simply that it might have the necessary tools to recover over time. Our findings suggest that the higher levels of C1q in the thalamus could contribute to several long-term effects of brain injury.”

The Paz Lab collaborated with Eleonora Aronica, MD, PhD, a neuropathologist at the University of Amsterdam, to validate their findings in human brain tissues obtained from autopsies, in which they found high levels of the C1q molecule in the thalamus 8 days after people had sustained a traumatic brain injury. In addition, by working with fellow Gladstone Assistant Investigator Ryan Corces, PhD, they determined that C1q in the thalamus likely came from microglia, the immune cells in the brain.

“Our study answered some very big questions in the field about where and how changes are happening in the brain after a trauma, and which ones are actually important for causing deficits,” says Paz.

The Right Window to Treat Chronic Effects After Traumatic Brain Injury

The C1q molecule, which is part of an immune pathway, has well-documented roles in brain development and normal brain functions. For instance, it protects the central nervous system from infection and helps the brain forget memories—a process needed to store new memories. The accumulation of C1q in the brain has also been studied in various neurological and psychiatric disorders and is associated, for example, with Alzheimer’s disease and schizophrenia.

“C1q can be both good and bad,” says Paz. “We wanted to find a way to prevent this molecule’s detrimental effect, but without impacting its beneficial role. This is an example of what makes neuroscience a really hard field these days, but it’s also what makes it exciting.”

She and her group decided to leverage the “latent phase” after a traumatic brain injury, during which changes are occurring in the brain but before long-term symptoms appear.

“My cousin, for example, was hit in the head when he was 10 years old, and the impact broke his skull and damaged his brain,” says Paz. “But it wasn’t until he was 20 that he developed epilepsy. This latent phase presents a window of opportunity for us to intervene in hopes of modifying the disease and preventing any complications.”

Paz reached out to her collaborators at Annexon Biosciences, who produce a clinical antibody that can block the activity of the C1q molecule. Then, her team treated the mice who sustained brain injury with this antibody to see if it might have beneficial effects.

When the researchers studied mice genetically engineered to lack C1q at the time of the trauma, the brain injury appeared much worse. However, when they selectively blocked C1q with the antibody during the latent phase, they prevented chronic inflammation and the loss of neurons in the thalamus.

“This indicates that the C1q molecule shouldn’t be blocked at the time of injury, because it’s likely very important at this stage for protecting the brain and helping prevent cell death,” says Holden. “But at later time points, blocking C1q can actually reduce harmful inflammatory responses. It’s a way of telling the brain, ‘It’s okay, you’ve done the protective part and you can now turn off the inflammation.’”

“There is a paucity of treatments for patients who have suffered from an acute brain injury,” says Ted Yednock, PhD, executive vice president and chief scientific officer at Annexon Biosciences, and an author of the study. “This result is exciting because it suggests that we could treat patients in the hours to days after an acute injury like traumatic brain injury to protect against secondary neuronal damage and provide significant functional benefit.”

Path to a Potential Treatment

In addition to chronic inflammation, Paz and her team also uncovered abnormal brain activity in the mice with traumatic brain injury.

First, the researchers noticed disruptions in sleep spindles, which are normal brain rhythms that occur during sleep. These are important for memory consolidation, among other things. The scientists also found epileptic spikes, or abnormal fluctuations in brain activity. These spikes can be disruptive to cognition and normal behavior, and are also indicative of a greater susceptibility to seizures.

The scientists observed that the anti-C1q antibody treatment not only helped restore the sleep spindles, but also prevented the development of epileptic activities.

“Overall, our study indicates that targeting the C1q molecule after injury could avoid some of the most devastating, long-term consequences of traumatic brain injury,” says Holden. “We hope this could eventually lead to the development of treatments for traumatic brain injury.”

Annexon’s anti-C1q inhibitors are designed to treat multiple autoimmune and neurological disorders, and are already being examined in clinical trials, including for an autoimmune disorder known as Guillain-Barré syndrome, where the drug has been shown to be safe in humans.

“The fact that the drug is already in clinical trials may speed the pace at which a treatment could eventually be made available to patients,” says Yednock. “We already understand doses of drug that are safe and effective in patients for blocking C1q in the brain, and could move directly into studies that ameliorate the chronic effects after traumatic brain injury.”

For Holden, who previously worked with individuals who experienced brain injury and heard many of their personal stories, the impact of this study is particularly meaningful.

“Brain injury is a hidden disability for many of the people I met,” she says. “The side effects they experience can be difficult to diagnose and their physicians often can’t provide any medical treatment. Being able to contribute to finding ways to treat the detrimental consequences of the injury after it happens is really inspiring.”

Paz and her lab are continuing to expand their understanding of what happens in the brain after injury. Next, they will focus on studying whether they can help prevent convulsive seizures, which are often reported by people with severe traumatic brain injuries.

“The holy grail would be to have a treatment that could be offered to a patient after a trauma and that would prevent chronic inflammation in the brain, sleep disruption, and seizures,” she adds. “Wouldn’t it be wonderful if our study helped make that a reality?”

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About the Study

The paper “Complement factor C1q mediates sleep spindle loss and epileptic spikes after mild brain injury" was published by the journal Science on September 10, 2021.

Other authors include Fiorella C. Grandi, Oumaima Aboubakr, Bryan Higashikubo, Frances S. Cho, Andrew H. Chang, and Allison R. Morningstar from Gladstone; Alejandro Osorio Forero and Anita Luthi from the University of Lausanne; Vidhu Mathur, Logan J. Kuhn, Poojan Suri, Sethu Sankaranarayanan, and Yaisa Andrews-Zwilling from Annexon Biosciences; Andrea J. Tenner from the University of California, Irvine; and Eleonora Aronica from the University of Amsterdam.

The work at Gladstone was funded by the Department of Defense (grant EP150038), as well as the National Institutes of Health (grants R01 NS078118, T32-GM007449, and F31 NS111819-01A1), the National Science Foundation (grants 1608236 and 1144247), Gladstone Institutes, the Michael Foundation, the Vilcek Foundation, the ARCS Foundation, the Kavli Institute for Fundamental Neuroscience at UCSF, the Ford Foundation Dissertation Fellowship, the Weill Foundation, the American Epilepsy Society, and the Graduate Division at UCSF.

About Gladstone Institutes

To ensure our work does the greatest good, Gladstone Institutes focuses on conditions with profound medical, economic, and social impact—unsolved diseases. Gladstone is an independent, nonprofit life science research organization that uses visionary science and technology to overcome disease. It has an academic affiliation with the University of California, San Francisco.

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JOURNAL

Science

DOI

10.1126/science.abj2685 

ARTICLE TITLE

Complement factor C1q mediates sleep spindle loss and epileptic spikes after mild brain injury

ARTICLE PUBLICATION DATE

10-Sep-2021

 

The mystery of the flexible shell

Peer-Reviewed Publication

PAUL SCHERRER INSTITUTE

 

IMAGE: THE SHELL OF THE BRACHIOPOD DISCINISCA TENUIS IS HARD AND BRITTLE BUT BECOMES SOFT AND FLEXIBLE WHEN EXPOSED TO WATER. view more 

CREDIT: BROOKHAVEN NATIONAL LABORATORY

An international research team with participation of the Paul Scherrer Institute PSI has revealed a secret about a marine animal's shell: The researchers have deciphered why the protective cover of the brachiopod Discinisca tenuis becomes extremely soft in water and gets hard again in the air. The study appears today in the journal Nature Communications.

 

The brachiopod Discinisca tenuis lives on the west coast of Africa.I It has a mineral-rich shell that protects it from harmful environmental influences. Bathing the shell in water leads to a structural change in the material: The flat, hard shell becomes so flexible that it can even be folded up without breaking. With the help of the Swiss Light Source SLS, the researchers have deciphered exactly how this transformation takes place.

 

The phenomenon was discovered by chance a few years ago by Fabio Nudelman, a materials chemist currently at the School of Chemistry, University of Edinburgh in Scotland. Maggie Cusack, who was recently appointed president of Munster Technological University in Ireland, had provided Nudelman with shells of the brachiopod Discinisca tenuis, which originally came from Namibia. When he wanted to wash the hard object, it suddenly became soft and flexible in contact with water. The shell had absorbed liquid and thereby changed its structure. The process was reversible: When the shell dried, it became hard and brittle again.

 

Together with colleagues from six countries, Nudelman set out to discover what exactly takes place during this unexpected transformation. "In its composition, the shell resembles bone," he explains. "But bone doesn't change its structure when it gets wet." The same goes for clams: If the animals need to adapt the properties of their shell to different environmental conditions, they normally have to rework the material in a lengthy and energetically costly process, by resorbing and redistributing minerals. It doesn't work simply through the absorption of water.

 

Hybrid material with a special trick

 

It was so-called cryo-tomography, performed at the Swiss Light Source SLS, that "opened the door to reveal the secret," says Johannes Ihli, a PSI researcher at SLS. With this technique, the researchers examined the material as if under a very high-resolution microscope, and in fact at extremely low temperatures. "At room temperature it would not have been possible, since the high-energy X-ray light would immediately alter the sensitive shell structure," Ihli explains.

 

The brachiopod's shell, which is no more than half a millimetre thick, consists of a hybrid material: mainly inorganic mineral in which organic polymers made from proteins and sugars are embedded. Bones, clam shells, and teeth are structured in a similar way out of a mixture of organic and inorganic material. The mineral that constitutes the main component of the shell is a type of fluoroapatite – similar to the material that makes up the enamel of our teeth.

 

Tiny nanocrystals of this material are arranged in layers. Nudelman compares it to brick walls: "In this analogy, the bricks are the nanocrystals, and the mortar between the bricks consists of organic molecules such as chitin and proteins." As the researchers observed, this "mortar" can absorb large amounts of water, causing it to swell up. Through the storage of water, it changes its structure: It becomes soft, and the bricks become movable with respect to each other. "Then water acts like a lubricant between the individual nanocrystals," Ihli explains. "The crystals can then slip against each other." Through this movement, the shell becomes flexible. The researchers found a network of pores in the shell that was especially effective in guiding water inside and rapidly distributing it throughout the material.

 

Evolutionary advantage

 

Discinisca tenuis lives in large clusters in tidal zones on the coast where, depending on the tide, the animals are exposed to strong waves or calm waters. The researchers speculate that it is probably advantageous if the animals can quickly adapt the softness or hardness of their shell to the respective situation: "This could prevent damage to the shell and thus be a key to the animals' survival," they write in the study. The phenomenon may even be more widespread than suspected: "We don't know how many other animal species there might be that have this kind of property," says Nudelman.

 

Aside from biology and evolution, the newly gained insights are also of interest for materials science: The development of a hard, brittle material whose stiffness can be controlled could hold promise for many applications. Sports clothing or helmets, for example, might be able to flexibly adapt to movements and always offer the protection required depending on the impact. Harnessing this phenomenon could also prove useful in developing bone-replacement materials.

 

Text: Paul Scherrer Institute/Brigitte Osterath

 

About PSI

The Paul Scherrer Institute PSI develops, builds and operates large, complex research facilities and makes them available to the national and international research community. The institute's own key research priorities are in the fields of matter and materials, energy and environment and human health. PSI is committed to the training of future generations. Therefore about one quarter of our staff are post-docs, post-graduates or apprentices. Altogether PSI employs 2100 people, thus being the largest research institute in Switzerland. The annual budget amounts to approximately CHF 400 million. PSI is part of the ETH Domain, with the other members being the two Swiss Federal Institutes of Technology, ETH Zurich and EPFL Lausanne, as well as Eawag (Swiss Federal Institute of Aquatic Science and Technology), Empa (Swiss Federal Laboratories for Materials Science and Technology) and WSL (Swiss Federal Institute for Forest, Snow and Landscape Research).

 

Participating research institutions

 

• Paul Scherrer Institute PSI, Villigen, Switzerland
• University of Bayreuth and Bavarian Polymer Institute, Bayreuth, Germany
• ETH Zurich and University of Zurich, Switzerland
• University of Bologna, Italy
• University of Edinburgh, UK
• Heriot-Watt University, Riccarton, UK
• University of Cambridge, UK
• Center for Functional Nanomaterials and National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA
• Munster Technological University, Cork und Kerry, Ireland

 

Contact

 

Dr. Johannes Ihli

Laboratory for Macromolecules and Bioimaging

Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland

Telephone: +41 56 310 40 50, e-mail: johannes.ihli@psi.ch [German, English]

 

Dr. Fabio Nudelman

School of Chemistry

University of Edinburgh, David Brewster 26 Road, Edinburgh EH9 3FJ, United Kingdom

Telephone: +44 131 650 7533, e-mail: fabio.nudelman@ed.ac.uk [English, Portuguese, Hebrew]

 

 

Original publication

 

Mechanical Adaptation of Brachiopod Shells Via Hydration-Induced Structural Changes

J. Ihli, A.S. Schenk, S. Rosenfeldt, K. Wakonig, M. Holler, G. Falini, L. Pasquini, E. Delacou, J. Buckman, T.S. Glen, T. Kress, E.H.R. Tsai, D.G. Reid, M.J. Duer, M. Cusack, F. Nudelman

Nature Communications, 10 September 2021 (online)

DOI: 10.1038/s41467-021-25613-4

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JOURNAL

Nature Communications

DOI

10.1038/s41467-021-25613-4 

SUBJECT OF RESEARCH

Animals

ARTICLE PUBLICATION DATE

10-Sep-2021

Iron supplements not linked to cognitive improvements for kids

A study in rural Bangladesh has concluded that preventive iron treatment has no impact on young children’s development

Peer-Reviewed Publication

WALTER AND ELIZA HALL INSTITUTE

 

IMAGE: A STUDY IN RURAL BANGLADESH HAS CONCLUDED THAT PREVENTIVE IRON TREATMENT HAS NO IMPACT ON YOUNG CHILDREN’S DEVELOPMENT. view more 

CREDIT: IMAGE COURTESY OF WEHI

A study in rural Bangladesh has concluded that preventive iron treatment has no impact on young children’s development.

Iron supplements are administered to young children worldwide to prevent anaemia, in line with global guidelines.

Led by WEHI Associate Professor Sant-Rayn Pasricha, in collaboration with Dr Jena Hamadani from the International Center for Diarrheal Diseases Research Bangladesh and Professor Beverley-Ann Biggs from the Doherty Institute, and published in the New England Journal of Medicine, the study measured the impact of iron supplements on child cognitive function, behaviour and development.

At a glance

• A randomised controlled trial of 3300 children in rural Bangladesh has concluded that while iron supplements improve anaemia in children, these interventions had no impact on cognitive function, behaviour or development.
• This study is expected to help inform future global health policy guidelines about the use of iron interventions for hundreds of millions of children worldwide.

Supplements show no impact on development

Iron was provided to eight-month-old children, as both iron drops and home fortification packets (multiple micronutrient powders), and neither intervention improved child development, although both improved anaemia.

The study measured children’s cognitive, language and motor development, as well as behaviour, and growth, including height and weight, and found iron supplements had no impact on any of these areas of development. 

Associate Professor Pasricha said the research could lead to major changes in global nutrition policy.

“We have been administering iron supplements to young children worldwide for decades in the belief that it had a positive impact on their development, without proper evidence it was actually beneficial,” he said.

“What we have demonstrated, is that while iron supplements improved anaemia in children, these interventions had no impact on growth, cognitive function, behaviour or development.”

“This has implications for how we treat iron deficiency and anaemia in babies and young children worldwide.”

Guiding future global health policy

Associate Professor Pasricha said anaemia in young children has long been linked with poor health outcomes and developmental delays.

“This led to policies of universal distribution of iron interventions to children, based on the assumption that iron would reverse poor child development,” he said. “Our rigorous study shows this is not the case.”

The study also evaluated adverse side effects in children who took the iron supplements preventatively.

Dr Hamadani said for some of these children the supplements may do more harm than good.

“In children taking iron supplements who did not have anaemia, they may actually have had increased presentations to clinics due to episodes of diarrhoea, possibly indicating iron interventions were doing more harm than good,” she said.

The World Health Organization (WHO) recommends iron supplements are given to all young children in low and middle-income countries where anaemia is common.

“We need to carefully reconsider the use of these interventions based on this study,” Associate Professor Pasricha said.

“It also puts into question the need to screen otherwise healthy, asymptomatic children for anaemia.”

Professor Biggs said she expected the findings to inform future global health policy guidelines about the use of iron interventions in young children.

“This study may also help inform guidelines for the treatment and prevention of anaemia in Indigenous populations in Australia,” she said.  

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This work was made possible with funding from the Australian National Health and Medical Research Council, the Government of Bangladesh, Global Affairs Canada, the Swedish International Development Cooperation Agency and the Victorian Government, with support from the Foreign, Commonwealth and Development Office in the United Kingdom.

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JOURNAL

New England Journal of Medicine

DOI

10.1056/NEJMoa2034187 

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Benefits and Risks of Universal Iron Interventions in Infants

ARTICLE PUBLICATION DATE

8-Sep-2021

Two departing FDA leaders among scientists who say Covid-19 vaccines do not currently 'show a need for boosting'

The current evidence on Covid-19 vaccines does not appear to support a need for booster shots in the general public right now, according to an international group of vaccine scientists, including some from the US Food and Drug Administration and the World Health Organization.

© Ahmad Gharabli/AFP/Getty Images

 A health worker prepares a dose of the Pfizer-BioNtech Covid-19 vaccine at Clalit Health Services in Jerusalem, on March 2, 2021.

By Jacqueline Howard, CNN

"Current evidence does not, therefore, appear to show a need for boosting in the general population, in which efficacy against severe disease remains high," the scientists write in a new opinion piece, published Monday in the medical journal The Lancet.

The authors of the paper include two senior FDA vaccine leaders, Dr. Philip Krause and Marion Gruber, who will be stepping down in October and November, the FDA announced late last month. No further details were released about their retirements, although they sparked questions about whether the departures would affect the agency's work.

The FDA and other public health agencies around the world continue to examine evidence on Covid-19 vaccine efficacy and the role booster doses of vaccine might play in improving immunity against the disease.

For the new paper in The Lancet, the scientists note that they reviewed randomized trials and observational studies on Covid-19 vaccines and consistently find that "vaccine efficacy is substantially greater against severe disease than against any infection; in addition, vaccination appears to be substantially protective against severe disease from all the main viral variants. Although the efficacy of most vaccines against symptomatic disease is somewhat less for the delta variant than for the alpha variant, there is still high vaccine efficacy against both symptomatic and severe disease due to the delta variant."

The scientists note that there is an opportunity right now to study variant-based boosters before there could be a widespread need for them. But they also argue in their paper that the current Covid-19 vaccine supply could "save more lives" if used in people who are not yet vaccinated than if used as boosters. In early August, the World Health Organization called for a moratorium on booster shots until at least the end of September.

"To date, none of these studies has provided credible evidence of substantially declining protection against severe disease, even when there appear to be declines over time in vaccine efficacy against symptomatic disease," the scientists write in their paper.

"The limited supply of these vaccines will save the most lives if made available to people who are at appreciable risk of serious disease and have not yet received any vaccine. Even if some gain can ultimately be obtained from boosting, it will not outweigh the benefits of providing initial protection to the unvaccinated," the scientists write. "If vaccines are deployed where they would do the most good, they could hasten the end of the pandemic by inhibiting further evolution of variants."

The paper published just shy of a month after US federal health officials announced plans for booster doses of Covid-19 vaccine to be offered this fall, starting September 20, subject to authorization from the FDA and sign off from the US Centers for Disease Control and Prevention.

The FDA's Vaccines and Related Biological Products Advisory Committee is meeting this Friday to discuss vaccine makers Pfizer and BioNTech's application to administer their Covid-19 vaccine as a third dose, or "booster" shot, to people ages 16 and older.

"The message that boosting might soon be needed, if not justified by robust data and analysis, could adversely affect confidence in vaccines and undermine messaging about the value of primary vaccination. Public health authorities should also carefully consider the consequences for primary vaccination campaigns of endorsing boosters only for selected vaccines," the scientists write in their new paper. "Booster programmes that affect some but not all vaccinees may be difficult to implement—so it will be important to base recommendations on complete data about all vaccines available in a country, to consider the logistics of vaccination, and to develop clear public health messaging before boosting is widely recommended."

Overall, the views in the new opinion paper do not reflect the views of the FDA, the agency told CNN in an emailed statement Monday.

"As noted in the article, the views of the authors do not represent the views of the agency. We are in the middle of a deliberative process of reviewing Pfizer's booster shot supplemental approval submission, and FDA as a matter of practice does not comment on pending matters before the agency," an FDA spokesperson said. "We look forward to a robust and transparent discussion on Friday about that application."

WHO push to wait on boosters

Last week, WHO Director-General Tedros Adhanom Ghebreyesus reiterated his call for wealthy nations to refrain from boosting their Covid-19 vaccinations until shots are available to more of the world. He urged countries to wait until at least the end of the year -- a longer timeline than WHO's initial call to wait till the end of September.

"Low and lower-middle income countries are not the second or third priority. Their health workers, older people, and other at risk groups have the same right to be protected," Tedros said.

"I will not stay silent when the companies and countries that control the global supply of vaccines think the world's poor should be satisfied with leftovers."

White House press secretary Jen Psaki then reiterated the Biden administration's view that the US can offer Covid-19 booster shots to Americans this fall while at the same time working to provide vaccines to people around the world who have not yet received a shot.

"Our view is that this is a false choice," Psaki told reporters at a White House briefing. "And the United States has donated and shared about 140 million doses with over 90 countries -- more than all other countries combined."

Sask. uses emergency powers to move health staff, quashing union talks

Saskatchewan’s government has invoked emergency powers to redeploy thousands of health-care workers to the COVID-19 pandemic’s front lines.

© Provided by Star Phoenix Premier Scott Moe speaks at a press conference to provide an update on COVID-19 measures in the province. Photo taken in Saskatoon, SK on Friday, September 10, 2021.

The order, issued Monday, quashes negotiations between the Saskatchewan Health Authority and unions representing the province’s health-care workers, who hoped a deal could be reached before swaths of members were potentially moved out of their existing jobs.

“We’re deeply disappointed,” said CUPE 5430 president Sandra Seitz. “We were in discussions with the SHA. We’re disappointed that they would take such a heavy hand.”

Seitz and leaders of other unions — the Saskatchewan Union of Nurses, SEIU-West, SGEU and the Health Sciences Association of Saskatchewan — spent days in discussion with the SHA about potentially resurrecting the letter of understanding that allowed thousands of workers to flit between different jobs to meet the needs of the pandemic in its earlier waves.

That was before Saskatchewan lifted its COVID-19 public health measures. Now, public health teams face unprecedented case counts without the full force of the health-care system helping them, and emergency room staff say they’re faced with a wave of patients as chronic fatigue contributes to understaffing.

Premier Scott Moe and SHA CEO Scott Livingstone said on Friday that they had returned to the bargaining table with unions to restore a letter of understanding to divert staff to emergency rooms and other settings. Moe said “help is on the way.”

Livingstone said there was a 160 per cent increase in unfilled shifts in July compared to the same month in 2020, and that COVID-19 case loads are expected to worsen. He said diverting staff would necessitate a “service slowdown” in other parts of the health-care system that, in some cases, will result in 100 per cent of certain services being cancelled.

“Case numbers are going up. They’re going up significantly, and they’ve already occurred — we just don’t know (about) them yet,” Livingstone said.

Union leaders have agreed the workloads in emergency rooms are untenable, but have raised concerns about resurrecting the old letter of understanding as a solution. SUN President Tracy Zambory said in a previous interview that she felt the letter was abused to force staff to frequently do work outside the terms of the collective agreement.

When asked if her union was considering a legal challenge, Seitz said it was too soon to answer.

In a prepared statement, Health Minister Paul Merriman thanked unions and workers, saying “they are all committed to continue problem solving and working together to meet the challenge of the pandemic.”

The Opposition NDP said invoking emergency powers was a sign of the government’s failure to control the spread of COVID-19. In a joint statement, labour critic Carla Beck and health critic Vicki Mowat said Moe “should have been working collaboratively with health-care workers throughout the summer to ensure these necessary agreements were in place.

“Instead, we now have arrangements being imposed on workers, record numbers of new COVID-19 cases, and non-COVID patients being forced to go without needed treatments. All of this could have been prevented if Scott Moe had listened to the experts and focused on controlling the fourth wave.”
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