Stacking Order and Strain Boosts Second-Harmonic Generation with 2D Janus Hetero-bilayers

Second-harmonic generation of 2D Janus MoSSe/MoS2 hetero-bilayers is optimized by stacking order and strain.
Image Credit: ©Nguyen Tuan Hung et al.

A group of researchers from Tohoku University, Massachusetts Institute of Technology (MIT), Rice University, Hanoi University of Science and Technology, Zhejiang University, and Oak Ridge National Laboratory have proposed a new mechanism to enhance short-wavelength light (100-300 nm) by second harmonic generation (SHG) in a two-dimensional (2D), thin material composed entirely of commonplace elements.

Since UV light with SHG plays an important role in semiconductor lithography equipment and medical applications that do not use fluorescent materials, this discovery has important implications for existing industries and all optical applications.

Study shows birds that have evolved greater complexity are less biodiverse

Songbirds have less complex skeletons and are species rich
Photo Credit: cocoparisienne

A new study of the evolution of birds shows that as their skeletons become more complex, they also decrease in diversity, with fewer species as they become more specialized in their niches. The findings, published in Nature Communications, show a correlation between skeleton complexity and bird diversity for the first time, and help biologists better understand why biodiversity varies across the birds.

Researchers at the Milner Centre for Evolution at the University of Bath looked at 983 species across all major groups of living birds and measured the complexity of their skeletons by comparing the bones in their fore limbs (wings) and hind limbs (legs).

They found that less complex birds - those with a smaller difference between their fore and hind limbs - had more species diversity than those with higher complexity and a larger difference between their limbs.

For example, birds such as pigeons, gulls and songbirds (passerines) have low skeletal complexity but a high diversity of species living in varied habitats across the world.

Bladderwrack at risk of destruction as ocean acidity rises

Bladderwrack is one of the most common macroalgae growing along Sweden’s coasts. It is widespread up to the Bothnian Sea. In Europe, it grows all the way down to Portugal’s Atlantic coast.
Photo Credit: Alexandra Kinnby

Climate change is increasing carbon dioxide levels in the sea, causing bladderwrack seaweed to grow more quickly and to increase in size along the coast. However, a scientific study by researchers from the University of Gothenburg shows that this growth is illusory as, in more acidic seas, the seaweed will be unable to withstand storms and powerful waves.

Ocean acidification is a consequence of the oceans absorbing a large proportion of the carbon dioxide that is being released into the atmosphere. The drop in pH changes the conditions for the plants and animals that live in our seas. The ocean has already become more acidic and the worst-case scenario from the IPCC predicts an even further drop in pH, from 8.1 today down to around 7.7 by the end of this century.

“That might not sound very much, but pH is a logarithmic scale so it’s a big difference. We are already seeing calcifying species such as shellfish finding it more difficult to survive today,” says Alexandra Kinnby, a marine biologist at the University of Gothenburg.

Extreme heat likely to cause next mass extinction

Photo Credit: Juli Kosolapova

A new study shows unprecedented heat is likely to lead to the next mass extinction since the dinosaurs died out, eliminating nearly all mammals in some 250 million years time.

The research, published in Nature Geoscience presents the first-ever supercomputer climate models of the distant future and demonstrates how climate extremes will dramatically intensify when the world’s continents eventually merge to form one hot, dry and largely uninhabitable supercontinent.

The findings project how these high temperatures are set to further increase, as the sun becomes brighter, emitting more energy and warming the Earth. 

Tectonic processes, occurring in the Earth’s crust and resulting in supercontinent formation would also lead to more frequent volcanic eruptions, which produce huge releases of carbon dioxide into the atmosphere, further warming the planet. 

Mammals, including humans, have survived historically thanks to their ability to adjust to weather extremes, especially through adaptations such as fur and hibernating in the cold, as well as short spells of warm weather hibernation. 

Individual neurons mix multiple RNA edits of key synapse protein, study finds

In a new study of a key protein that regulates how neurons communicate via the release of neurotransmitters, scientists tracked how RNA editing affected the protein's distribution and performance. Here three different edits of complexin (yellow) resulted in different distributions of the protein in segments of motor neurons as well as different degrees of function. The left panel shows distribution of unedited complexin while the right two panels show distribution of two different edited variants.
Image Credit: Littleton Lab/Picower Institute

Neurons stochastically generated up to eight different versions of a protein-regulating neurotransmitter release, which could vary how they communicate with other cells.

Neurons are talkers. They each communicate with fellow neurons, muscles, or other cells by releasing neurotransmitter chemicals at “synapse” junctions, ultimately producing functions ranging from emotions to motions. But even neurons of the exact same type can vary in their conversational style. A new open-access study in Cell Reports by neurobiologists at The Picower Institute for Learning and Memory highlights a molecular mechanism that might help account for the nuanced diversity of neural discourse.

The scientists made their findings in neurons that control muscles in Drosophila fruit flies. These cells are models in neuroscience because they exhibit many fundamental properties common to neurons in people and other animals, including communication via the release of the neurotransmitter glutamate. In the lab of Troy Littleton, Menicon Professor in MIT’s departments of Biology and Brain and Cognitive Sciences, which studies how neurons regulate this critical process, researchers frequently see that individual neurons vary in their release patterns. Some “talk” more than others.

Researchers Develop AI Model to Improve Tumor Removal Accuracy During Breast Cancer Surgery

Radiology-specific
Image Credit: Courtesy of UNC School of Medicine

Kristalyn Gallagher, DO, Kevin Chen, MD, and Shawn Gomez, EngScD, in the UNC School of Medicine have developed an AI model that can predict whether or not cancerous tissue has been fully removed from the body during breast cancer surgery.

Artificial intelligence (AI) and machine learning tools have received a lot of attention recently, with the majority of discussions focusing on proper use. However, this technology has a wide range of practical applications, from predicting natural disasters to addressing racial inequalities and now, assisting in cancer surgery.

A new clinical and research partnership between the UNC Department of Surgery, the Joint UNC-NCSU Department of Biomedical Engineering, and the UNC Lineberger Comprehensive Cancer Center has created an AI model that can predict whether or not cancerous tissue has been fully removed from the body during breast cancer surgery. Their findings were published in Annals of Surgical Oncology.

Potentially hazardous La Niña weather more common, lasting longer

Wildfire in California.
Photo Credit: Ross Stone

The climate event La Niña that can cause devastating weather, impacting communities and industries from agriculture to tourism, is happening more frequently and lasting longer, according to new public impact research from the University of Hawaiʻi at Mānoa.

Atmospheric scientist Bin Wang from the School of Ocean and Earth Science and Technology (SOEST) found that five out of six La Niña events since 1998 have lasted more than one year, including an unprecedented triple-year event. The study was published in Nature Climate Change.

“The clustering of multiyear La Niña events is phenomenal given that only 10 such events have occurred since 1920,” said Wang, emeritus professor of atmospheric sciences in SOEST.

El Niño and La Niña, the warm and cool phases of a recurring climate pattern across the tropical Pacific, affect weather and ocean conditions, which can impact the public by influencing the marine environment and fishing industry in Hawaiʻi and throughout the Pacific Ocean. Long-lasting La Niñas could also cause persistent climate extremes.

Determining why so many multiyear La Niña events have emerged recently and whether they will become more common has sparked worldwide discussion among climate scientists, yet answers remain elusive.

Widely-used COVID-19 antiviral could be helping SARS-CoV-2 to evolve

Image Credit: visuals3Dde

The drug works by disrupting the virus’s genome, causing it to develop random mutations as it replicates, weakening the virus to prevent replication, thereby enabling clearance of infection.

But in research published today in Nature, scientists have shown that in some cases, mutated forms of the virus have been able to be transmitted from patients treated with molnupiravir and spread within the community.

Dr Christopher Ruis from the Department of Medicine at the University of Cambridge said: “Molnupiravir is one of a number of drugs being used to fight COVID-19. It belongs to a class of drugs that can cause the virus to mutate so much that it is fatally weakened. But what we’ve found is that in some patients, this process doesn’t kill all the viruses, and some mutated viruses can spread. This is important to take into account when assessing the overall benefits and risks of molnupiravir and similar drugs.”

Molnupiravir, marketed under the brand name Lagevrio, is licensed for the treatment of COVID-19 in several countries, including the UK, USA and Japan. It has been used to treat the disease since late 2021.

Heat extremes in the soil are underestimated

Climate change intensifies extreme heat in the soil.
Photo Credit: André Künzelmann (UFZ)

For a long time, little attention was paid to soil temperatures. In contrast to air temperatures near the surface, hardly any reliable data was available because of the considerably more complex measurement. A research team leaded by the Helmholtz Centre for Environmental Research (UFZ) with participation of Leipzig University has now found not only that soil and air temperatures can differ but also that climate change has a much greater impact on the intensity and frequency of heat extremes in the soil than in the air. According to a study recently published in Nature Climate Change, this is particularly the case in Central Europe.

For the study, the research team coordinated by UFZ remote sensing scientist Dr Almudena García-García collected data from a wide range of sources: data from meteorological measuring stations, remote sensing satellites, the ERA5-Land data reanalysis set, and simulations of Earth system models. The researchers fed these data into the TX7d index, which is defined as the average of the daily maximum temperature in the hottest week of the year. It reflects the intensity of heat extremes (i.e. how high extreme temperatures can be). The researchers thus calculated the index for the 10-cm-thick upper soil layer and for the near-surface air at a height of up to 2 m for the years 1996 to 2021. At two thirds of the 118 meteorological measuring stations evaluated, the trend in heat extremes is stronger in the soil than in the air. “This means that heat extremes develop much faster in the soil than in the air”, García-García, lead author of the study. Based on the data available, this is especially true in Germany, Italy, and southern France. In terms of figures, according to station data, the intensity of heat extremes in Central Europe is increasing 0.7°C/decade faster in the soil than in the air.

Marker for brain inflammation finally decoded

TSPO protein (in green) was quantified in microglia (in red) in proximity to lesion characteristic of Alzheimer’s disease, the amyloid plaques (in blue) and pTau lesions (in white), in post mortem human brain samples.
Image Credit: Stergios Tsartsalis

An international team co-led by UNIGE and HUG has decoded the only protein that can be used to "see" neuroinflammation. This discovery will improve the understanding of neurological and psychiatric disease mechanisms.

 Inflammation is the sign that our body is defending itself against aggression. But when this response escalates, for example in the brain, it can lead to serious neurological or psychiatric diseases. A team from the University of Geneva (UNIGE), the University Hospitals of Geneva (HUG), Imperial College London and Amsterdam UMC, investigated a marker protein targeted by medical imaging to visualize cerebral inflammation, but whose interpretation was still uncertain. The team reveals that a large quantity of this protein goes hand in hand with a large quantity of inflammatory cells, but its presence is not a sign of their overactivation. These results, published in Nature Communications, pave the way for optimal observation of neuroinflammatory processes and a re-reading of previous studies on the subject.