How to generate new neurons in the brain

Mitochondria (green) in proliferating (A) and dormant (B) cells. Newly produced neurons (C) (red) in the dentate gyrus with cell nuclei (blue) and a marker for immature neurons (green).
Image Credit: © Knobloch Lab – UNIL

A team of biologists led by UNIGE and UNIL has discovered how to awaken neural stem cells and reactivate them in adult mice.

Some areas of the adult brain contain quiescent, or dormant, neural stem cells that can potentially be reactivated to form new neurons. However, the transition from quiescence to proliferation is still poorly understood. A team led by scientists from the Universities of Geneva (UNIGE) and Lausanne (UNIL) has discovered the importance of cell metabolism in this process and identified how to wake up these neural stem cells and reactivate them. Biologists succeeded in increasing the number of new neurons in the brain of adults and even elderly mice. These results, promising for the treatment of neurodegenerative diseases, are to be discovered in the journal Science Advances.

Stem cells have the unique ability to continuously produce copies of themselves and give rise to differentiated cells with more specialized functions. Neural stem cells (NSCs) are responsible for building the brain during embryonic development, generating all the cells of the central nervous system, including neurons.

Glacier National Park could provide climate haven for Canada lynx

An image of a Canada lynx taken by a motion sensitive camera as part of a study conducted in Glacier National Park
Photo Credit: Alissa Anderson

Glacier National Park is home to around 50 Canada lynx, more than expected, surprising scientists who recently conducted the first parkwide occupancy survey for the North American cat. 

The Washington State University-led survey reveals the iconic predator resides across most of Glacier’s 1,600 square-mile landscape, although at lower densities than in the core of its range further north. 

“The population in the park is still substantial and exceeded our expectations,” said Dan Thornton, WSU wildlife ecologist and senior author of the study published in the Journal of Wildlife Management. “Our results suggest the park could provide a much-needed climate refuge for the cats in the future.” 

Canada lynx are known for their long, black ear tufts and ability to hunt almost ghost-like across the surface of deep snow. Historically, the predator’s habitat extended from Alaska and Canada south down into much of the Northern United States. In the lower 48 today, the Canada lynx exists only in several disjunct populations in Maine, Minnesota, Montana, Colorado, Idaho and Washington.  

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.