Left ventricular hypertrophy and left diastolic dysfunction are measures of structural and functional heart damage, which have been associated with an increased risk of cardiovascular-related death in adults. These cardiac measures are also used in the paediatric population as indicators of premature heart damage.

Arterial stiffness estimated from carotid-femoral pulse wave velocity has been discovered as a novel cause of increased blood pressure, insulin resistance, and metabolic syndrome in adolescents and young adults. It was also recently shown that increased blood pressure in adolescence may cause premature heart damage, but it is not known whether arterial stiffness could independently cause structural and functional damage to the heart.

The current study was conducted among 1,856 adolescents of whom 1,011 were female. The adolescents were 17 years old at baseline, and they were followed up for 7 years until young adulthood at age 24 years. Arterial stiffness, carotid intima-media thickness, and evidence of heart damage were assessed at baseline and follow-up. Signs of heart structure damage are left ventricular hypertrophy and high relative wall thickness, whereas signs of heart function damage are left ventricular diastolic dysfunction and increased left ventricular filling pressure.

During the 7-year follow-up period, the prevalence of heart structural damage among adolescents doubled. With extensive control for fat mass, muscle mass, glucose, insulin, blood pressure, lipids, smoking status, sedentary time, physical activity, socio-economic status, and family history of cardiovascular disease, and using adults’ cut points for diagnosing heart damage, it was observed that adolescents in the highest tertile category of arterial stiffness and carotid intima-media thickness had a 23 — 27% increased risk of progressively worsening structural heart damage.

Only arterial stiffness appears to independently cause both structural and functional heart damage, whereas increased carotid wall thickness does not seem to have a causal role. Increased carotid wall thickness is an early indicator of atherosclerosis, whereas increased arterial stiffness describes arteriosclerosis. The study further reported that arterial stiffness caused heart damage by increasing blood pressure and insulin resistance. The increase in blood pressure explained 34% of the heart damage caused by arterial stiffness. Moreover, insulin resistance explained 15% of the heart damage caused by arterial stiffness.

“We are seeing for the first time that arterial stiffness is a novel cause of several diseases such as hypertension, insulin resistance, metabolic syndrome, and heart damage in the young population. Among adults, arterial stiffness is currently being established as a cause of type 2 diabetes. We discovered that approximately 50% of the deleterious role of arterial stiffness in causing heart damage is enhanced by the mechanism of increased blood pressure and insulin resistance. Thus, preventing and lowering blood pressure and insulin resistance may potentially diminish the negative impact of arterial stiffness on the heart, by up to half,” says Andrew Agbaje, a physician and clinical epidemiologist at the University of Eastern Finland.

“Experimental and clinical intervention studies are urgently needed on comprehensive approaches to treating and reversing arterial stiffness from adolescence. At least, targeting blood pressure and insulin resistance leaves the problem half-solved,” Agbaje continues.

Dr Agbaje’s research group (urFIT-child) is supported by research grants from Jenny and Antti Wihuri Foundation, the Finnish Cultural Foundation Central Fund, the Finnish Cultural Foundation North Savo Regional Fund, the Orion Research Foundation, the Aarne Koskelo Foundation, the Antti and Tyyne Soininen Foundation, the Paulo Foundation, the Yrjö Jahnsson Foundation, the Paavo Nurmi Foundation, the Finnish Foundation for Cardiovascular Research, Ida Montin Foundation, Eino Räsänen Fund, Matti and Vappu Maukonen Fund, and the Foundation for Pediatric Research.

The team studied orangutans at a long-term monitoring site, Suaq Balimbing, in Sumatra. Orangutans at the site have been habituated over decades to the presence of humans, thus offering scientists a rare opportunity to observe wild great apes at close range. Caroline Schuppli, director of the Suaq Project and the study’s first author, became interested in how wild orangutans would react when presented with something unfamiliar.

“Curiosity is a trait that has driven the exceptional ability of humans to learn and innovate,” says Schuppli, a group leader at MPI-AB. “If we want to know how the trait evolved in us, we have to study it in our closest living relatives.”

Curiosity, which describes an individual’s motivation to learn about the unknown, has been studied before in great apes; however, due to the logistical difficulties of studying wild animals, almost all tests have occurred in captivity. “We know that apes are very curious to explore when they are in the safe and controlled conditions of a zoo,” says Schuppli. “But these results tell us little about what really triggered or suppressed curiosity over our evolutionary history.”

About ten years ago, Schuppli and collaborators first attempted to assess curiosity in wild orangutans with an experiment inspired by captive studies. They roamed Suaq, peppering the forest with foreign objects for the orangutans to find: a bright red flag; plastic flowers and fruits; a stuffed toy. The results were stark. “They hardly ever came near any of the items,” she remembers. “You could see them making huge circles in the forest to avoid the experiment.”

Schuppli realized that testing orangutans’ reaction to novelty in nature would require reimagining the past paradigm. “The challenge was figuring out how to entice them with something that was novel, but also familiar enough not to scare them off,” she says. Over the years Schuppli perfected just such an object: a piece of tree trunk with a natural hole filled with local forest honey. The tree hole and food were familiar, but deploying these in an unusual way represented a novel foraging situation. With a team of local and international scientists, Schuppli hoisted the experimental log into trees about 10 meters from orangutans — and watched what happened.

During the trials, the orangutans spent on average 30 minutes in the vicinity of the novel log. During this time, they explored the novel log by intensively observing it over extended periods of time and approaching it closely. Overall, however, orangutans rarely touched the branch directly; and when they did, they often used a tool, such as a stick to do so. “The orangutans were pretty cautious,” says Tri Rahmaeti, a team member from Universitas Nasional in Indonesia and co-author on the study. “The honey reward could have easily been scooped out of the log using a finger, but they still preferred to use a tool so they didn’t have to make physical contact.”

But there were significant differences in the behaviors. Using statistical techniques, the team uncovered traits of individuals and features in the environment that amplified exploration. Young orangutans were far more likely than adults to observe and approach. And, orangutans were more likely to approach the log if they saw another individual heading that way too. The habitat also seemed to play a role: in areas with abundant food, orangutans observed more but approached less.

Says Schuppli: “On the one hand, the results confirmed our hunch that orangutans in the wild are not that keen to explore new objects. This could be because in nature, orangutans live very long lives in stable habitats where novelty is rare. So, the potential risk of approaching something unknown doesn’t outweigh the potential reward.”

“On the other hand, the experiment showed that there is flexibility in the behavior. Orangutans have the potential to be curious about novelty in nature, but only under certain conditions. And by experimentally testing this in a wild population, we pinned down the conditions.”

Of these conditions, Schuppli finds the social factor most illuminating. “Orangutans are the least social of all great apes, and yet we find that the presence of association partners increases their curiosity,” she says.

This has fascinating implications for understanding learning and innovation — the products of curiosity that fueled the success of our species. “We often think of learning and innovation as solo acts, but this might not have been the case in our early history,” says Schuppli. “If novelty was the spark, then our social lives might have provided the accelerant.”

To achieve this, we need so-called quantum materials: substances that exhibit pronounced quantum physical effects. One such material is graphene. This two-dimensional structural form of carbon has unusual physical properties, such as extraordinarily high tensile strength, thermal and electrical conductivity — as well as certain quantum effects. Restricting the already two-dimensional material even further, for instance, by giving it a ribbon-like shape, gives rise to a range of controllable quantum effects.

This is precisely what Mickael Perrin’s team leverage in their work: For several years now, scientists in Empa’s Transport at Nanoscale Interfaces laboratory, headed by Michel Calame, have been conducting research on graphene nanoribbons under Perrin’s leadership. “Graphene nanoribbons are even more fascinating than graphene itself,” explains Perrin. “By varying their length and width, as well as the shape of their edges, and by adding other atoms to them, you can give them all kinds of electrical, magnetic, and optical properties.”

Ultimate precision — down to single atoms

Research on the promising ribbons isn’t easy. The narrower the ribbon, the more pronounced its quantum properties are — but it also becomes more difficult to access a single ribbon at a time. This is precisely what must be done in order to understand the unique characteristics and possible applications of this quantum material and distinguish them from collective effects.

In a new study published recently in the journal Nature Electronics, Perrin and Empa researcher Jian Zhang, together with an international team, have succeeded for the first time in contacting individual long and atomically precise graphene nanoribbons. Not a trivial task: “A graphene nanoribbon that is just nine carbon atoms wide measures as little as 1 nanometer in width,” Zhang says. To ensure that only a single nanoribbon is contacted, the researchers employed electrodes of a similar size: They used carbon nanotubes that were also only 1 nanometer in diameter.

Precision is key for such a delicate experiment. It begins with the source materials. The researchers obtained the graphene nanoribbons via a strong and long-standing collaboration with Empa’s nanotech surfaces laboratory, headed by Roman Fasel. “Roman Fasel and his team have been working on graphene nanoribbons for a long time and can synthesize many different types with atomic precision from individual precursor molecules,” Perrin explains. The precursor molecules came from the Max Planck Institute for Polymer Research in Mainz.

As is often required for advancing the state of the art, interdisciplinarity is key, and different international research groups were involved, each bringing in their own specialty to the table: The carbon nanotubes were grown by a research group at Peking University, and to interpret the results of the study, the Empa researchers collaborated with computational scientists at the University of Warwick. “A project like this would not be possible without collaboration,” Zhang emphasizes.

Contacting individual ribbons by nanotubes posed a considerable challenge for the researchers. “The carbon nanotubes and the graphene nanoribbons are grown on separate substrates,” Zhang explains. “First, the nanotubes need to be transferred to the device substrate and contacted by metal electrodes. Then we cut them with high-resolution electron-beam lithography to separate them into two electrodes.” Finally, the ribbons are transferred onto the same substrate. Precision is key: Even the slightest rotation of the substrates can significantly reduce the probability of successful contact. “Having access to high-quality infrastructure at the Binnig and Roher Nanotechnology Center at IBM Research in Rüschlikon was essential to test and implement this technology,” Perrin says.

From computers to energy converters

The scientists confirmed the success of their experiment through charge transport measurements. “Because quantum effects are usually more pronounced at low temperature, we performed the measurements at temperatures close to absolute zero in a high vacuum,” Perrin explains. But he is quick to add yet another particularly promising quality of graphene nanoribbons: “Due to the extremely small size of these nanoribbons, we expect their quantum effects to be so robust that they are observable even at room temperature.” This, the researcher says, could allow us to design and operate chips that actively harness quantum effects without the need for an elaborate cooling infrastructure.

“This project enables the realization of single nanoribbon devices, not only to study fundamental quantum effects such as how electrons and phonons behave at the nanoscale, but also to exploit such effects for applications in quantum switching, quantum sensing, and quantum energy conversion,” adds Hatef Sadeghi, a professor at the Univeristy of Warwick who collaborated on the project.

Graphene nanoribbons are not ready for commercial applications just yet, and there is still a lot of research to be done. In a follow-up study, Zhang and Perrin aim to manipulate different quantum states on a single nanoribbon. In addition, they plan on creating devices based on two ribbons connected in series, forming a so-called double quantum dot. Such a circuit could serve as a qubit — the smallest unit of information in a quantum computer. Moreover, Perrin, in the context of his recently obtained ERC Starting Grant and an SNSF Eccellenza Professorial Fellowship, plans to explore the use of nanoribbons as highly-efficient energy converters. In his inaugural lecture at ETH Zurich, he paints a picture of a world, in which we can harness electricity from temperature difference, while hardly losing any energy as heat — this would indeed be a real quantum leap.

The Coliseum is the size of one-and-a-half football fields and contains layer upon layer of prints preserved in rock. The site is a record of multiple species of dinosaurs over many generations that thrived in what is now Interior Alaska nearly 70 million years ago. The scientists describe the site in a paper recently published in the journal Historical Biology.

“It’s not just one level of rock with tracks on it,” said Dustin Stewart, the paper’s lead author and a former UAF graduate student who published the paper as part of his master’s thesis. “It is a sequence through time. Up until now, Denali had other track sites that are known, but nothing of this magnitude.”

At first glance, the site is unremarkable in the context of the park’s vast landscape: just a layered, rocky outcrop rising 20-some stories from its base.

“When our colleagues first visited the site, they saw a dinosaur trackway at the base of this massive cliff,” said Pat Druckenmiller, senior author of the paper and director of the University of Alaska Museum of the North. “When we first went out there, we didn’t see much either.”

Stewart recalled being initially underwhelmed when he approached the site at the end of a seven-hour hike. Then dusk approached, and the team took another look.

“When the sun angles itself perfectly with those beds, they just blow up,” he said. “Immediately all of us were just flabbergasted, and then Pat said, ‘Get your camera.’ We were freaking out.”

In the Late Cretaceous Period, the cliffs that make up The Coliseum were sediment on flat ground near what was likely a watering hole on a large flood plain. As Earth’s tectonic plates collided and buckled to form the Alaska Range, the formerly flat ground folded and tilted vertically, exposing the cliffs covered with tracks.

The tracks are a mix of hardened impressions in the ancient mud and casts of tracks created when sediment filled the tracks and then hardened.

“They are beautiful,” Druckenmiller said. “You can see the shape of the toes and the texture of the skin.”

In addition to the dinosaur tracks, the research team found fossilized plants, pollen grains, and evidence of freshwater shellfish and invertebrates.

“All these little clues put together what the environment looked like as a whole,” Stewart said.

The area was part of a large river system, he said, with ponds and lakes nearby. The climate in the area was warmer than today, more like the Pacific Northwest. There were coniferous and deciduous trees and an understory of ferns and horsetails.

Based on the tracks, a variety of juvenile to adult dinosaurs frequented the area over thousands of years. Most common were large plant-eating duck-billed and horned dinosaurs. The team also documented rarer carnivores, including raptors and tyrannosaurs, as well as small wading birds.

Every year, thousands of people visit Denali National Park and Preserve to experience the stunning natural landscape and environment, Druckenmiller said. “It’s amazing to know that around 70 million years ago, Denali was equally impressive for its flora and fauna.

“It was forested and it was teeming with dinosaurs,” he said. “There was a tyrannosaur running around Denali that was many times the size of the biggest brown bear there today. There were raptors. There were flying reptiles. There were birds. It was an amazing ecosystem.”

Preserving fossil sites like The Coliseum is an important part of the National Park Service’s mission, said Denny Capps, the park’s geologist.

“On one hand, we must protect world-class fossil sites like The Coliseum from disturbance and theft,” he said. “On the other hand, we encourage visitors to explore for fossils in their geologic context to better grasp the evolution of landscapes and ecosystems through time, while leaving them undisturbed for others to appreciate.”

Druckenmiller plans to continue collaborating with the National Park Service to study The Coliseum and other track sites.

“Our track research in the park complements our work on dinosaur bones we collect in northern Alaska, along the Colville River,” Druckenmiller said. “Denali National Park and Preserve is a world-class area for dinosaur tracks. There is a lifetime of exploring left to do, and I can only wonder what other surprises await.”

“Our study suggests that patients with hidden consciousness can hear and comprehend verbal commands, but they cannot carry out those commands because of injuries in brain circuits that relay instructions from the brain to the muscles,” says study leader Jan Claassen, MD, associate professor of neurology at Columbia University Vagelos College of Physicians and Surgeons and chief of critical care and hospitalist neurology at NewYork-Presbyterian/Columbia University Irving Medical Center.

The findings could help physicians more quickly identify brain-injured patients who might have hidden consciousness and better predict which patients are likely to recover with rehabilitation.

Brain circuits disrupted in patients with hidden consciousness

Hidden consciousness, also known as cognitive motor dissociation (CMD), occurs in about 15% to 25% of patients with brain injuries stemming from head trauma, brain hemorrhage, or cardiac arrest.

In previous research, Claassen and colleagues found that subtle brainwaves detectable with EEG are the strongest predictor of hidden consciousness and eventual recovery for unresponsive brain-injured patients.

But the precise pathways in the brain that become disrupted in this condition were unknown.

In the new study, the researchers used EEG to examine 107 brain injury patients. The technique can determine when patients are trying, though unable, to respond to a command such as “keep opening and closing your right hand.”

The analysis detected CMD in 21 of the patients.

The researchers then analyzed structural MRI scans from all of the patients.

“Using a technique we developed called bi-clustering analysis, we were able to identify patterns of brain injury that are shared among patients with CMD and contrast to those without CMD,” says co-lead author Qi Shen, PhD, associate research scientist in the Claassen lab and an expert in signal processing, machine learning, and biostatistics.

The researchers found that all of the CMD patients had intact brain structures related to arousal and command comprehension, supporting the notion that these patients were hearing and understanding the commands but were unable to carry them out.

“We saw that all of the CMD patients had deficits in brain regions responsible for integrating comprehended motor commands with motor output, preventing CMD patients from acting on verbal commands,” says Claassen.

The findings may allow researchers to better understand which brain injury patients have CMD, which will be useful for clinical trials that support recovery of consciousness.

More research is required before these approaches can be applied to clinical practice. “However, our study shows that it may be possible to screen for hidden consciousness using widely available structural brain imaging, moving the detection of CMD one step closer to general clinical use,” Claassen says.

“Not every critical care unit may have resources and staff that is trained in using EEG to detect hidden consciousness, so MRI may offer a simple way to identify patients who require further screening and diagnosis.”