Scientists Study Whether Flows in the Earth's Core Can Affect Global Processes

Scientists are trying to answer the question of how changes in the Earth's rotational speed affect tectonic activity.
Photo Credit: NASA

Scientists from Moscow State University, together with colleagues from the Ural Federal University, the University of Helsinki and the University of Oxford, have studied the response of viscous incompressible fluid flow in a spherical layer of the Earth to random external forcing. The results help scientists understand how random changes in the planet's rotation speed affect the tectonic activity that leads to earthquakes, volcanic eruptions and tsunamis. The research has been published in the Philosophical Transactions of the Royal Society, the world's oldest scientific journal. 

"In our research we considered flows of a viscous incompressible fluid induced either by rotation of the inner sphere only or by co-rotation of the spheres. The magnitude of the rotation speed of the inner sphere was subjected to the influence of noise - random deviations in time of the angular rotation speed from the average values. Mean flow generation was found to occur under the action of additive noise. Calculations have shown that the response to noise depends on how the flow was created - by rotation of the inner sphere only or by rotation of both spheres," explains Maria Gritsevich, Senior Researcher at the Ural Federal University and Assistant Professor at the University of Helsinki.

Revealed: Molecular “superpower” of antibiotic-resistant bacteria

Scanning electron micrograph of en:Clostridioides difficile bacteria from a stool sample
Photo Credit: Public Health Image Library

A species of ordinary gut bacteria that we all carry flourishes when the intestinal flora is knocked out by a course of antibiotics. Since the bacteria is naturally resistant to many antibiotics, it causes problems, particularly in healthcare settings. A study led from Lund University in Sweden now shows how two molecular mechanisms can work together make the bacterium extra resistant. “Using this knowledge, we hope to be able to design even better medicines,” says Vasili Hauryliuk, senior lecturer at Lund University, who led the study.

The threat from antibiotic resistant bacteria is as well-known as it is grave. Last year, The Lancet reported that an estimated 1.27 million people died in 2019 as a result of bacterial infection that could not be treated with existing medicines. To tackle this threat is it is essential to understand the underpinning molecular mechanisms.

Researchers discover how some brain cells transfer material to neurons in mice

Neuronal accumulation of ribosomal reporter (green) in the brain of adult mice.
Resized Image using AI by SFLORG
Photo Credit Olga Chechneva

Researchers at UC Davis are the first to report how a specific type of brain cells, known as oligodendrocyte-lineage cells, transfer cell material to neurons in the mouse brain. Their work provides evidence of a coordinated nuclear interaction between these cells and neurons. The study was published today in the Journal of Experimental Medicine.

“This novel concept of material transfer to neurons opens new possibilities for understanding brain maturation and finding treatments for neurological conditions, such as Alzheimer’s disease, cerebral palsy, Parkinson’s and Huntington’s disease,” said corresponding author Olga Chechneva. Chechneva is an assistant project scientist at UC Davis Department of Biochemistry and Molecular Medicine and independent principal investigator in the Institute for Pediatric Regenerative Medicine at Shriners Children's Northern California.

Our knowledge about this mechanism is extremely new, and it opens many questions for understanding how neurons work and their biological relevance in many neurological disorders. This is very exciting.”—Olga Chechneva

Graphene ‘tattoo’ treats cardiac arrhythmia with light

Graphene implant on tattoo paper
Photo Credit: Ning Liu/University of Texas at Austin

First graphene-based cardiac implant senses irregularities, then stimulates the heart

Researchers led by Northwestern University and the University of Texas at Austin (UT) have developed the first cardiac implant made from graphene, a two-dimensional super material with ultra-strong, lightweight and conductive properties.

Similar in appearance to a child’s temporary tattoo, the new graphene “tattoo” implant is thinner than a single strand of hair yet still functions like a classical pacemaker. But unlike current pacemakers and implanted defibrillators, which require hard, rigid materials that are mechanically incompatible with the body, the new device softly melds to the heart to simultaneously sense and treat irregular heartbeats. The implant is thin and flexible enough to conform to the heart’s delicate contours as well as stretchy and strong enough to withstand the dynamic motions of a beating heart.

After implanting the device into a rat model, the researchers demonstrated that the graphene tattoo could successfully sense irregular heart rhythms and then deliver electrical stimulation through a series of pulses without constraining or altering the heart’s natural motions. Even better: The technology also is optically transparent, allowing the researchers to use an external source of optical light to record and stimulate the heart through the device. 

Physicists find unusual waves in nickel-based magnet

(Left) In nickel molybdate crystals made of two parts nickel, three parts molybdenum and eight parts oxygen, nickel ions are subject to both tetrahedral and octahedral crystalline environments, and the ions are locked in triangular lattices in each environment. (Right) Crystal electric field spin excitons from tetrahedral sites in nickel molybdate crystals form a dispersive, diffusive pattern around the Brillouin zone boundary, likely due to spin entanglement and geometric frustrations. Left and right halves of the image show different model calculations of these patterns.
Illustration Credit: Courtesy of Bin Gao/Rice University

Perturbing electron spins in a magnet usually results in excitations called “spin waves” that ripple through the magnet like waves on a pond that’s been struck by a pebble. In a new study, Rice University physicists and their collaborators have discovered dramatically different excitations called “spin excitons” that can also “ripple” through a nickel-based magnet as a coherent wave.

In a study published in Nature Communications, the researchers reported finding unusual properties in nickel molybdate, a layered magnetic crystal. Subatomic particles called electrons resemble miniscule magnets, and they typically orient themselves like compass needles in relation to magnetic fields. In experiments where neutrons were scattered from magnetic nickel ions inside the crystals, the researchers found that two outermost electrons from each nickel ion behaved differently. Rather than aligning their spins like compass needles, the two canceled one another in a phenomenon physicists call a spin singlet.

Environmental toxin PCB found in deep sea trench

A sediment core has just been retrieved from the Atacama trench during an expedition with the research vessel R/V Sonne.
Photo Credit: Anni Glud / University of Southern Denmark

Despite being banned in numerous countries since the 1970s, PCBs continue to persist in the environment. Recent findings from deep-sea researchers reveal that PCBs have been detected at the depths of the Atacama Trench in the Pacific Ocean, highlighting the enduring impact of these toxic pollutants.

Throughout their deep-sea expedition, the research team retrieved sediment cores from multiple locations within the Atacama Trench and conducted meticulous analyses to detect PCB occurrences. Astonishingly, every single sample of surface sediment analyzed from all five locations within the trench was found to contain PCBs, indicating the widespread presence of these hazardous pollutants even in the remote depths of the ocean.

The groundbreaking study, helmed by Professor Anna Sobek from Stockholm University's Department of Environmental Science and Professor Ronnie N. Glud, esteemed director of the Danish Center for Hadal Research at the University of Southern Denmark, has been published in the prestigious scientific journal Nature Communications. This significant contribution sheds light on the alarming presence of PCBs in the Atacama Trench and underscores the urgent need for continued research and action to mitigate their adverse effects on marine ecosystems.

Leaps in artificial blood research aim to improve product safety, efficacy

Artificial blood has been used in a variety of clinical trials, but no safe alternative has yet made it to market.
Image Credit: Narupon Promvichai

Researchers have made huge strides in ensuring that red blood cell substitutes – or artificial blood – are able to work safely and effectively when transfused into the bloodstream.  

The key is to make the artificial blood molecules big enough so they don’t leak from blood vessels into tissue and cause dangerous cardiovascular side effects, notes a new study led by researchers from The Ohio State University. 

Although blood loss is typically treated by transfusing units of donated blood, in cases where transfusions aren’t readily available or time is too limited to screen for patient blood type compatibility (such as in certain rural areas or on the battlefield), artificial blood products offer medical professionals more flexibility for treatment. In clinical trials, previous generations of these blood substitutes often resulted in several poor health outcomes, as individuals experienced symptoms ranging from narrowing of blood vessels and high blood pressure to tissue injury.   

In this study, researchers found that a certain sized fraction of red blood cell substitute can provide a range of health benefits, and can decrease the risk of cardiovascular side effects – if its components are the right size. 

UC Irvine physicists discover first transformable nano-scale electronic devices

The golden parts of the device depicted in the above graphic are transformable, an ability that is “not realizable with the current materials used in industry,” says Ian Sequeira, a Ph.D. student who worked to develop the technology in the laboratory of Javiar Sanchez-Yamahgishi, UCI assistant professor of physics & astronomy.
Image Credit: Yuhui Yang / UCI

The nano-scale electronic parts in devices like smartphones are solid, static objects that once designed and built cannot transform into anything else. But University of California, Irvine physicists have reported the discovery of nano-scale devices that can transform into many different shapes and sizes even though they exist in solid states.

It’s a finding that could fundamentally change the nature of electronic devices, as well as the way scientists research atomic-scale quantum materials. The study is published this week in Science Advances.

“What we discovered is that for a particular set of materials, you can make nano-scale electronic devices that aren’t stuck together,” said Javier Sanchez-Yamagishi, an assistant professor of physics & astronomy whose lab performed the new research. “The parts can move, and so that allows us to modify the size and shape of a device after it’s been made.”

New approach estimates long-term coastal cliff loss

Jane Willenbring sampling shore platform bedrock in Del Mar with a hammer and chisel.
Photo Credit: Travis Clow

A new method for estimating cliff loss over thousands of years in Del Mar, California, may help reveal some of the long-term drivers of coastal cliff loss in the state.

In parts of California’s iconic mountainous coasts, breathtaking beauty is punctuated by brusque signs warning spectators to stay back from unstable cliffs. The dangers of coastal erosion are an all-too-familiar reality for the modern residents of these communities. Now, with a new tool, researchers are bringing historical perspective to the hotly debated topic of how to manage these disappearing coastlines.

Using a model that incorporates measurements of the amount of time coastal cliffs and their remnant deposits were exposed at the Earth’s surface, Stanford researchers found that the rate of cliff erosion in the past 100 years is similar to that of the past 2,000 years. The proof-of-concept, published in the Journal of Geophysical Research: Earth Surface April 17, opens the possibility of using this new approach to understand the long-term history of coastal cliff erosion, or retreat, in other parts of the state. The work was conducted in Del Mar, California, a beach town in San Diego County with infrastructure atop its coastal bluffs.

New genetic target for male contraception identified

Photo Credit: Filipe Almeida

Discovery of a gene in multiple mammalian species could pave the way for a highly effective, reversible and non-hormonal male contraceptive for humans and animals.

Washington State University researchers identified expression of the gene, Arrdc5, in the testicular tissue of mice, pigs, cattle and humans. When they knocked out the gene in mice, it created infertility only in the males, impacting their sperm count, movement and shape. The researchers detailed their findings in the journal Nature Communications.

“The study identifies this gene for the first time as being expressed only in testicular tissue, nowhere else in the body, and it’s expressed by multiple mammalian species,” said Jon Oatley, senior author and professor in WSU’s School of Molecular Biosciences. “When this gene is inactivated or inhibited in males, they make sperm that cannot fertilize an egg, and that’s a prime target for male contraceptive development.”

While other molecular targets have been identified for potential male contraceptive development, the Arrdc5 gene is specific to the male testes and found in multiple species. Importantly, lack of the gene also causes significant infertility creating a condition called oligoasthenoteratospermia or OAT. This condition, the most common diagnosis for human male infertility, shows a decrease in the amount of sperm produced, slowed mobility and distorted shape so that the sperm are unable to fuse with an egg.