AI offers ‘paradigm shift’ in Stanford study of brain injury

Models discovered by the Constitutive Artificial Neural Network outperform existing models for brain tissue.
Image Credit: Ellen Kuhl

By helping researchers choose among thousands of available computational models of mechanical stress on the brain, AI is yielding powerful new insight on traumatic brain injury.

From the gridiron to the battlefield, the study of traumatic brain injury has exploded in recent years. Crucial to understanding brain injury is the ability to model the mechanical forces that compress, stretch, and twist the brain tissue and cause damage that ranges from fleeting to fatal.

Researchers at Stanford University now say they have tapped artificial intelligence to produce a profoundly more accurate model of how deformations translate into stresses in the brain and believe that their approach could reveal a more definitive understanding of when and why concussion sometimes leads to lasting brain damage, and other times not.

“The problem in brain modeling to date is that the brain is not a homogeneous tissue – it’s not the same in every part of the brain. Yet, trauma is often pervasive,” said Ellen Kuhl, professor of mechanical engineering, director of the Living Matter Lab, and senior author of a new study appearing in the journal, Acta Biomaterialia. “The brain is also ultrasoft, much like Jell-O, which makes both testing and modeling physical effects on the brain very challenging.”

Pseudomonas aeruginosa Bacteria produce a molecule that paralyzes immune system cells

Human endothelial cells use the molecules cadherin (green) and actin (purple) to form a flexible barrier around blood vessels. After adding the isolated LecB, their localization in the cell changes significantly: in the right half of the image, cadherin is no longer on the outside of the cell, but near the nucleus (blue).
Image Credit: Yubing Guo / Universities of Freiburg and Strasbourg

Bacteria of the species Pseudomonas aeruginosa are antibiotic-resistant hospital germs that can enter blood, lungs and other tissues through wounds and cause life-threatening infections. In a joint project, researchers from the Universities of Freiburg and Strasbourg in France have discovered a mechanism that likely contributes to the severity of P. aeruginosa infections. At the same time, it could be a target for future treatments. The results recently appeared in the journal EMBO Reports.

Many bacterial species use sugar-binding molecules called lectins to attach to and invade host cells. Lectins can also influence the immune response to bacterial infections. However, these functions have hardly been researched so far. A research consortium led by Prof. Dr. Winfried Römer from the Cluster of Excellence CIBSS - Centre for Integrative Biological Signaling Studies at the University of Freiburg and Prof. Dr. Christopher G. Mueller from the IBMC - Institute of Molecular and Cell Biology at the CNRS/University of Strasbourg has investigated the effect of the lectin LecB from P. aeruginosa on the immune system. It found that isolated LecB can render immune cells ineffective: The cells are then no longer able to migrate through the body and trigger an immune response. The administration of a substance directed against LecB prevented this effect and led to the immune cells being able to move unhindered again.

Flamingos form cliques with like-minded pals

The partner of one Caribbean flamingo helps it out in an argument with another pair.
Photo Credit Paul Rose

Flamingos form cliques of like-minded individuals within their flocks, new research shows.

Scientists analyzed the personalities and social behavior of Caribbean and Chilean flamingos.

Birds of both species tended to spend time with others whose personality was similar to their own.  

The study, by the University of Exeter and the Wildfowl & Wetlands Trust (WWT), reveals the complex nature of flamingo societies and could help in the management of captive flocks.

“Our previous research has shown that individual flamingos have particular ‘friends’ within the flock,” said Dr Paul Rose, from WWT and Exeter’s Centre for Research in Animal Behavior.

“In this study, we wanted to find out whether individual character traits explain why these friendships form.

“The answer is yes – birds of a feather flock together.

Mysterious new behavior seen in whales may be recorded in ancient manuscripts

Flinders University Diagram of humpback engaged in trap feeding; with a jaw either flush with the waterline, or raised to a similar height to the rostrum.
Image Credit: John McCarthy 

In 2011, scientists recorded a previously unknown feeding strategy in whales around the world. Now, researchers in Australia think they may have found evidence of this behavior being described in ancient accounts of sea creatures, recorded more than 2,000 years ago.

They believe that misunderstandings of these descriptions contributed to myths about medieval sea monsters.

Whales are known to lunge at their prey when feeding, but recently whales have been spotted at the surface of the water with their jaws open at right angles, waiting for shoals of fish to swim into their mouths. 

This strategy seems to work for the whales because the fish think they have found a place to shelter from predators, not realizing they are swimming into danger.

It’s not known why this strategy has only recently been identified, but scientists speculate that it’s a result of changing environmental conditions - or that whales are being more closely monitored than ever before by drones and other modern technologies.

Blue whale foraging and reproduction are related to environmental conditions, study shows

A blue whale surfaces
Photo Credit: Three-shots

A new study of New Zealand blue whales’ vocalizations indicates the whales are present year-round in the South Taranaki Bight and their behavior is influenced by environmental conditions in the region.

The findings are a significant advancement in researchers’ understanding of the habitat use and behavior of this population of blue whales, which Oregon State University researchers first identified as genetically distinct from other blue whale populations less than a decade ago.  

“We went from not knowing 10 years ago whether this was a distinct population to now understanding these whales’ ecology and their response to changing environmental conditions,” said the study’s lead author, Dawn Barlow, a postdoctoral scholar in OSU’s Marine Mammal Institute. “These findings can inform conservation management of this blue whale population and their habitat.”

The patterns and intensity of the whales’ calls and songs over two years showed strong seasonality in their foraging and breeding behavior, and the vocalizations changed based on environmental conditions such as a documented marine heatwave, Barlow said.

“During the marine heatwave, feeding-related calls were reduced, reflecting poor foraging conditions during that period,” Barlow said. “But we also saw changes in vocalizations in the next breeding period, an indication that they put less effort into reproduction following a period of poor feeding conditions.”

Breakthrough in Tin-Vacancy Centers for Quantum Network Applications

Tin-vacancy (Sn-V) centers in diamond have the potential to function as quantum nodes in quantum networks to transmit information. However, they pose limitations while showing optical properties to generate quantum entanglement. Tokyo Tech researchers have now overcome this challenge by generating stable Sn-V centers that can produce photons with nearly identical frequencies and linewidths, paving the way for the advancement of Sn-V centers as a quantum-light matter interface.

Quantum entanglement refers to a phenomenon in quantum mechanics in which two or more particles become linked such that the state of each particle cannot be described independently of the others, even when they are separated by a large distance. The principle, referred to by Albert Einstein as "spooky action at a distance", is now utilized in quantum networks to transfer information. The building blocks of these networks—quantum nodes—can generate and measure quantum states.

Among the candidates that can function as quantum nodes, the Sn-V center in diamond (a defect where a tin (Sn) atom replaces a carbon atom, resulting in an interstitial Sn atom between two carbon vacancies) has been shown to have suitable properties for quantum network applications. The Sn-V center is expected to exhibit a long spin coherence time in the millisecond range at Kelvin temperatures, allowing it to maintain its quantum state for a relatively long period of time. However, these centers have yet to produce photons with similar characteristics, which is a necessary criterion for creating remote entangled quantum states between quantum network nodes.

Zombie forests

As the climate changes, plants often struggle to keep up. In many areas, the vegetation that stands today may not be well adapted for the climate it is now living in. After a major disturbance, such as a wildfire, the plant community likely will not return.

Video Credit: Lindsay Filgas, Madison Pobis & Rob Jordan

The researchers created maps showing where warmer weather has left trees in conditions that don’t suit them, making them more prone to being replaced by other species. The findings could help inform long-term wildfire and ecosystem management in these “zombie forests.”

Like an old man suddenly aware the world has moved on without him, the conifer tree native to lower elevations of California’s Sierra Nevada mountain range finds itself in an unrecognizable climate. A new Stanford-led study reveals that about a fifth of all Sierra Nevada conifer forests – emblems of Western wilderness – are a “mismatch” for their regions’ warming weather. The paper, published Feb. 28 in PNAS Nexus, highlights how such “zombie forests” are temporarily cheating death, likely to be replaced with tree species better adapted to the climate after one of California’s increasingly frequent catastrophic wildfires.

“Forest and fire managers need to know where their limited resources can have the most impact,” said study lead author Avery Hill, a graduate student in biology at Stanford’s School of Humanities & Sciences at the time of the research. “This study provides a strong foundation for understanding where forest transitions are likely to occur, and how that will affect future ecosystem processes like wildfire regimes.” Hill led a related study this past November showing how wildfires have accelerated the shifting of Western trees’ ranges.

Could Space Dust Help Protect the Earth from Climate Change?

Illustration Credit: Ben Bromley/University of Utah

On a cold winter day, the warmth of the Sun is welcome. Yet as humanity emits more greenhouse gases, the Earth's atmosphere traps more and more of the Sun's energy, which steadily increases the Earth's temperature. One strategy for reversing this trend is to intercept a fraction of sunlight before it reaches our planet.

For decades, scientists have considered using screens or other objects to block just enough of the Sun’s radiation — between 1 or 2 percent — to mitigate the effects of global warming. Now, a new study led by scientists at the Center for Astrophysics | Harvard & Smithsonian and the University of Utah explores the potential of using dust to shield sunlight.

The paper, published today in the journal PLOS Climate, describes different properties of dust particles, quantities of dust and the orbits that would be best suited for shading Earth. The team found that launching dust from Earth to a way station at the "Lagrange Point" between Earth and the Sun would be most effective but would require an astronomical cost and effort.

The team proposes moondust as an alternative, arguing that lunar dust launched from the Moon could be a low-cost and effective way to shade the Earth.

A motion freezer for particles

Illustration Credit: Jakob Hüpfl / TU Wien

Tailor-made laser light fields can be used to slow down the movement of several particles and thus cool them down to extremely low temperatures - as shown by a team from TU Wien.

Using lasers to slow down atoms is a technique that has been used for a long time already: If one wants to achieve low-temperature world records in the range of absolute temperature zero, one resorts to laser cooling, in which energy is extracted from the atoms with a suitable laser beam.

Recently, such techniques have also been applied to small particles in the nano- and micro-meter range. This already works quite well for individual particles – but if you want to cool several particles at once, the problem turns out to be much more difficult. Prof. Stefan Rotter and his team at the Institute of Theoretical Physics at TU Wien have now presented a method with which extremely effective cooling can also be achieved in this case.

Steel Was Already Used in Europe 2900 Years Ago

Using geochemical analyses, the researchers were able to prove that stone stelae on the Iberian peninsula that date back to the Final Bronze Age feature complex engravings that could only have been done using tempered steel. This was backed up by metallographic analyses of an iron chisel from the same period and region that showed the necessary carbon content to be proper steel.
Photo Credits: Rafael Ferreiro Mählmann (A), Bastian Asmus (B), Ralph Araque Gonzalez (C-E)

A study by an international and interdisciplinary team headed by Freiburg archaeologist Dr. Ralph Araque Gonzalez from the Faculty of Humanities has proven that steel tools were already in use in Europe around 2900 years ago. Using geochemical analyses, the researchers were able to prove that stone stelae on the Iberian Peninsula that date back to the Final Bronze Age feature complex engravings that could only have been done using tempered steel. This was backed up by metallographic analyses of an iron chisel from the same period and region (Rocha do Vigio, Portugal, ca. 900 BCE) that showed the necessary carbon content to be proper steel. The result was also confirmed experimentally by undertaking trials with chisels made of various materials: only the chisel made of tempered steel was suitably capable of engraving the stone. 

Until recently it was assumed that it was not possible to produce suitable quality steel in the Early Iron Age and certainly not in the Final Bronze Age, and that it only came to be widespread in Europe under the Roman Empire. “The chisel from Rocha do Vigio and the context where it was found show that iron metallurgy including the production and tempering of steel were probably indigenous developments of decentralized small communities in Iberia, and not due to the influence of later colonization processes. This also has consequences for the archaeological assessment of iron metallurgy and quartzite sculptures in other regions of the world,” explains Araque Gonzalez. The study ‘Stone-working and the earliest steel in Iberia: Scientific analyses and experimental replications of final bronze age stelae and tools’ has been published in the Journal of Archaeological Science.