Electrons are quick-change artists in molten salts, chemists show

When exposed to radiation, electrons produced within molten zinc chloride, or ZnCl2, can be observed in three distinct singly occupied molecular orbital states, plus a more diffuse, delocalized state.
Illustration Credit: Hung H. Nguyen/University of Iowa

In a finding that helps elucidate how molten salts in advanced nuclear reactors might behave, scientists have shown how electrons interacting with the ions of the molten salt can form three states with different properties. Understanding these states can help predict the impact of radiation on the performance of salt-fueled reactors.

The researchers, from the Department of Energy’s Oak Ridge National Laboratory and the University of Iowa, computationally simulated the introduction of an excess electron into molten zinc chloride salt to see what would happen.

They found three possible scenarios. In one, the electron becomes part of a molecular radical that includes two zinc ions. In another, the electron localizes on a single zinc ion. In the third, the electron is delocalized, or spread out diffusely over multiple salt ions.

Because molten salt reactors are one of the reactor designs under consideration for future nuclear power plants, “the big question is what happens to molten salts when they’re exposed to high radiation,” said Vyacheslav Bryantsev, leader of the Chemical Separations group at ORNL and one of the scientists on the study and an author of the paper. “What happens to the salt that is used to carry the fuel in one of those advanced reactor concepts?”

Lactate-producing bacteria inside tumors promote resistance to radiation therapy

Lactobacillus iners taken from cervical cancer tumor samples spread on agar plate.
Image Credit: Courtesy of David Lo.

Researchers at The University of Texas MD Anderson Cancer Center have discovered that lactate-producing intratumoral bacteria drives resistance to radiation therapy, suggesting that lactic acid-producing bacteria present in various cancers may serve as novel therapeutic targets.

The study, published today in Cancer Cell, reported that a particular bacterial species, Lactobacillus iners (L. iners), caused cancer cells to respond to radiation by rewiring metabolic signaling pathways to resist treatment. The researchers also found that L. iners was associated with poorer clinical outcomes in patients with cervical cancer.

“These lactic acid-producing bacteria are seemingly responsible for changing signaling pathways by priming cancer cells to use lactate instead of glucose to fuel growth and proliferation from oxidative stress following radiation therapy,” said corresponding author Lauren Colbert, M.D., assistant professor of Radiation Oncology. “This is potentially paradigm shifting, and we currently are working on novel approaches to target these specific intratumoral bacteria. We are hopeful that these efforts will lead us to approaches that can benefit patients across several types of cancer.”

Astronomers detect most distant fast radio burst to date

This artist’s impression (not to scale) illustrates the path of the fast radio burst FRB 20220610A, from the distant galaxy where it originated all the way to Earth, in one of the Milky Way’s spiral arms. The source galaxy of FRB 20220610A, pinned down thanks to ESO’s Very Large Telescope, appears to be located within a small group of interacting galaxies. It’s so far away its light took eight billion years to reach us, making FRB 20220610A the most distant fast radio burst found to date. 
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Credit: ESO/M. Kornmesser

An international team has spotted a remote blast of cosmic radio waves lasting less than a millisecond. This 'fast radio burst' (FRB) is the most distant ever detected. Its source was pinned down by the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in a galaxy so far away that its light took eight billion years to reach us. The FRB is also one of the most energetic ever observed; in a tiny fraction of a second it released the equivalent of our Sun’s total emission over 30 years.

The discovery of the burst, named FRB 20220610A, was made in June last year by the ASKAP radio telescope in Australia and it smashed the team’s previous distance record by 50 percent.

“Using ASKAP’s array of dishes, we were able to determine precisely where the burst came from,” says Stuart Ryder, an astronomer from Macquarie University in Australia and the co-lead author of the study published today in Science. “Then we used [ESO’s VLT] in Chile to search for the source galaxy, finding it to be older and further away than any other FRB source found to date and likely within a small group of merging galaxies.”

Rice researcher scans tropical forest with mixed-reality device

Rice doctoral alumnus Daniel Gorczynski wearing a Microsoft HoloLens headset.
Photo Credit: Jeff Fitlow/Rice University

Rice University scientists used a commercially available mixed-reality headset with custom-designed software to measure and analyze forest floor vegetation, demonstrating a correlation between animal diversity and the mapped habitat of a Tanzanian national park. According to the paper published in the journal Ecology, the greater the microhabitat surface area, the richer the biodiversity of its mammals.

Traditional habitat field research requires a significant amount of time and effort, but Rice postdoctoral researcher Daniel Gorczynski reduced those costs by incorporating a Microsoft HoloLens with his innovative VegSense software. Gorczynski and his advisor, assistant professor of biosciences Lydia Beaudrot, created VegSense to help researchers measure animal habitats, while the HoloLens was initially designed to improve work quality and outcomes in manufacturing, engineering, healthcare and education.

“Because the HoloLens is a mixed-reality device, you can see both the projected mesh over the forest structure as well as your local surroundings,” Gorczynski said.

New mollusk and crustacean species in symbiosis with worms in dead coral rocks

Bonellia sp. aff. minor (green) and its burrow associates -- Basterotia bonelliphila (right) and Leucothoe bonelliae (left) -- in dead coral rock. The inside of the burrows is partly occupied by sandy sediments collected by Bo. sp. aff. minor.
Image Credit: KyotoU/Ryutaro Goto

Good real estate is not easy to find, even for sea creatures. Sometimes, push comes to shove, and species resort to competition or conquering before weighing the benefits of sharing an ecosystem like housemates.

There is abundant research on live-in symbionts, which share the burrows of other organisms in sand and mud on the seabed. However, studies on burrow niches in rigid substrates, such as rocks on the seabed, have been scarce.

Now, a research team led by Kyoto University has discovered the symbiotic communities of invertebrates in dead coral gravel on the shallow, warm-temperate coast of the Kii Peninsula in western Japan. New bivalve species and sideswimmers have been found to live communally with the greenish Bonellia spoonworm.

A miniature magnetic resonance imager made of diamond

Prof. Dominik Bucher uses defects in diamond (NV-centers) as quantum sensors for NMR spectroscopy on the nano- to microscale. His research group works at the unique interface between quantum sensing and (bio) chemistry with interdisciplinary approaches from applied quantum physics, chemical synthesis and biophysics. The over goal is to perform NMR spectroscopy on smallest length-scales - from nano- and surface science to microfluidics and single-cell biology.
Photo Credit: Andreas Heddergott / TUM

The development of tumors begins with minuscule changes within the body's cells; ion diffusion at the smallest scales is decisive in the performance of batteries. Until now the resolution of conventional imaging methods has not been high enough to represent these processes in detail. A research team led by the Technical University of Munich (TUM) has developed diamond quantum sensors which can be used to improve resolution in magnetic imaging.

Nuclear magnetic resonance (NMR) is an important imaging method in research which can be used to visualize tissue and structures without damaging them. The technique is better known from the medical field as Magnetic Resonance Imaging (MRI), where the patient is moved into the bore of a large magnet on a table. The MRI device creates a very strong magnetic field which interacts with the tiny magnetic fields of the hydrogen nuclei in the body. Since the hydrogen atoms are distributed in a particular way amongst different types of tissues, it becomes possible to differentiate organs, joints, muscles and blood vessels.

Physical theory improves protein folding prediction

Protein folding models. Four iterations of WSME, from the original to the new, and two specialized versions for more specific circumstances.
Illustration Credit: ©2023 Ooka & Arai CC-BY

Proteins are important molecules that perform a variety of functions essential to life. To function properly, many proteins must fold into specific structures. However, the way proteins fold into specific structures is still largely unknown. Researchers from the University of Tokyo developed a novel physical theory that can accurately predict how proteins fold. Their model can predict things previous models cannot. Improved knowledge of protein folding could offer huge benefits to medical research, as well as to various industrial processes.

You are literally made of proteins. These chainlike molecules, made from tens to thousands of smaller molecules called amino acids, form things like hair, bones, muscles, enzymes for digestion, antibodies to fight diseases, and more. Proteins make these things by folding into various structures that in turn build up these larger tissues and biological components. And by knowing more about this folding process, researchers can better understand more about the processes that constitute life itself. Such knowledge is also essential to medicine, not only for the development of new treatments and industrial processes to produce medicines, but also for knowledge of how certain diseases work, as some are examples of protein folding gone wrong. So, to say proteins are important is putting it mildly. Proteins are the stuff of life.

Biodegradable plastics still damaging to fish

Professor Indrawati Oey, of the Department of Food Science, and Dr Bridie Allan, of the Department of Marine Science, hold the biodegradable plastic used in the study and a photo of the mottled triplefin, the species analyzed.
Photo Credit: University of Otago

Biodegradable plastics may not be the solution to plastic pollution many hoped for, with a University of Otago study showing they are still harmful to fish.

Petroleum-derived microplastics are known to impact marine life, but little is known about the impact of biodegradable alternatives.

The study, published in Science of the Total Environment and funded by a University of Otago Research Grant, is the first to assess the impact petroleum-derived plastic and biodegradable plastic have on wild fish.

Lead author Ashleigh Hawke, who completed a Master of Science in Otago’s Department of Marine Science, says petroleum-derived plastic exposure negatively affected the fish’s escape performance, routine swimming, and aerobic metabolism.

New insights into the genetics of the common octopus: genome at the chromosome level decoded

Octopus vulgaris
Photo Credit: ©Antonio, Valerio Cirillo (BEOM SZN), 2023

Octopuses are fascinating animals – and serve as important model organisms in neuroscience, cognition research and developmental biology. To gain a deeper understanding of their biology and evolutionary history, validated data on the composition of their genome is needed, which has been lacking until now. Scientists from the University of Vienna together with an international research team have now been able to close this gap and, in a study, determined impressive figures: 2.8 billion base pairs - organized in 30 chromosomes. What sounds so simple is the result of complex, computer-assisted genome analyses and comparisons with the genomes of other cephalopod species. This groundbreaking research has just been published in the renowned journal G3: Genes / Genomes / Genetics.

Octopuses, together with squid and cuttlefish, belong to a group of coleoid cephalopods consisting of several hundreds of species that are characterized by highly diversified lifestyles, body structure and adaptations to their environment. The study of these animals looks back on a long tradition, especially since the neuronal plasticity of the octopus brain – meaning the brain's ability to change and adapt as you learn and experience new things – provides evidence for the existence of functionally analogous structures to the brains of mammals. This is making them a comparative model group for neurophysiological studies. Also, their ability to regenerate parts of their bodies as well as the rapid changes of their body patterns, which are important for camouflage and communication, make octopuses a popular research subject for studying how these innovative traits arose – and how they have changed – during evolution.

Climate change could limit bats' lifespans

Greater Horseshoe Bat
Photo Credit: Professor Gareth Jones

The extraordinary lifespans of bats could be under threat from rising global temperatures, according to new research.

A study by researchers from the University of Bristol and University College Dublin has found that the hibernation cycle of a group of wild greater horseshoe bats affected by fluctuations in the weather had altered the molecular mechanism thought to give bat species their long lives.

Telomeres are pieces of DNA that act as a protective structure at the end of chromosomes. Each time a cell divides, they shorten. And it is this shortening that is associated with aging and aging-related diseases.

Data from the new study showed that bats who more frequently arose from hibernating due to warmer conditions during the 2019/2020 hibernation period had significantly shorter telomeres compared to those recorded in previous, colder, winters.

“We were surprised and then worried at this finding, given that the predicted rise in global temperatures could limit the beneficial effects of hibernation in our wild bats.” said UCD Professor Emma Teeling.

Superdeep diamonds provide a window on supercontinent growth

Deep diamonds from Collier-4 from the Juina area, Brazil. 
Photo Credit: Sarah Milne, University of Alberta.

Diamonds contain evidence of the mantle rocks that helped buoy and grow the ancient supercontinent Gondwana from below, according to new research from a team of scientists led by Suzette Timmerman—formerly of the University of Alberta and now at the University of Bern—and including Carnegie’s Steven Shirey, Michael Walter, and Andrew Steele. Their findings, published in Nature, demonstrate that superdeep diamonds can provide a window through space and time into the supercontinent growth and formation process.

For billions of years, Earth’s landmasses have been ripped apart and smashed back together by plate tectonics, periodically forming giant supercontinents. This formation process results from large-scale convection of the planet’s mantle.  But the records of these events are poorly preserved, because the oceanic crust is young and continually sinks beneath the planet’s surface by a process called subduction, while the continental crust only provides a limited view of Earth’s deep workings.

Surprisingly, the research team was able to show that superdeep diamonds that formed between 300 and 700 kilometers below Earth’s surface can reveal how material was added to the base of a once-mighty supercontinent.

“These diamonds allow us to see how deep plate tectonic processes relate to the supercontinent cycle,” Shirey said.

How the Greenland ice sheet can be saved

Greenland binds enormous amounts of water with its ice sheet. If it melts, sea levels will rise worldwide.
Photo Credit: rawpixel

Climate researchers around the world are sounding the alarm about exceeding critical temperature values on the Earth. If temperatures pass what are called tipping points, the results could be catastrophic. An international team of researchers, including members from the Technical University of Munich (TUM), has now demonstrated in simulations that the temperature tipping point for the Greenland ice sheet can be exceeded in certain cases for a short time, as long as extreme countermeasures are taken afterwards. If the ice mass melted entirely, the result would be a massive rise in the sea level.

Greenland is the second largest permanently ice-covered surface on the Earth; only Antarctica is larger. The Greenland ice sheet is drastically impacted by the effects of climate change. If the ice sheet melts completely, it would cause a sea level rise of more than seven meters – a catastrophe for coastal regions worldwide and for the people who live there. The critical threshold for the worst-case scenario is between 1.7 and 2.3 degrees Celsius of global warming above the preindustrial level on an annual average. Until now climate research has assumed that if this point is exceeded, the Greenland ice sheet would be lost forever. However, the international research team has now been able to show in a large set of simulations that there would be a way back after passing the tipping point.

California Supervolcano is Cooling Off but May Still Cause Quakes

View is toward the east across the northern part of Long Valley Caldera, California, United States. The caldera rim extends east from the Glass Creek flow (lower left) to Bald Mountain and Glass Mountain in the far distance. Lookout Mountain is behind the tree
Photo Credit: United States Geological Survey

Since the 1980s, researchers have observed significant periods of unrest in a region of California's Eastern Sierra Nevada mountains characterized by swarms of earthquakes as well as the ground inflating and rising by almost half an inch per year during these periods. The activity is concerning because the area, called the Long Valley Caldera, sits atop a massive dormant supervolcano. Seven hundred and sixty thousand years ago, the Long Valley Caldera was formed in a violent eruption that sent 650 cubic kilometers of ash into the air—a volume that could cover the entire Los Angeles area in a layer of sediment 1 kilometer thick.

What is behind the increased activity in the last few decades? Could it be that the area is preparing to erupt again? Or could the uptick in activity actually be a sign that the risk of a massive eruption is decreasing?

To answer these questions, Caltech researchers have created the most detailed underground images to date of the Long Valley Caldera, reaching depths up to 10 kilometers within the Earth's crust. These high-resolution images reveal the structure of the earth beneath the caldera and show that the recent seismic activity is a result of fluids and gases being released as the area cools off and settles down.

Finding Order in the Disorder: New Insights into Seemingly Structureless Regions of Proteins

Protein condensates (shown here in a microscope image) are critical to the process of gene expression in cells, and condensate formation depends on proteins’ intrinsically disordered regions.
Image Credit: Amy Strom, Princeton University

Howard Hughes Medical Institute Investigators Cigall Kadoch and Clifford Brangwynne teamed up to challenge long-held beliefs in the scientific community about how – or even if – structureless, unorganized regions of proteins play specific roles in causing or preventing disease pathogenesis. Their work was published earlier this month in the journal Cell.

To understand the significance of the duo’s findings, it helps to first dive deep into the ways in which cells alter genomic structure through a process known as chromatin remodeling. About two meters – or six and a half feet – of DNA are packed inside each cell’s nucleus, which measures no larger than a pinhead. To fit in that space, DNA winds around proteins, forming a compact structure called chromatin. At the Dana-Farber Cancer Institute, Kadoch and her lab have spent years studying chromatin remodeling complexes – molecular machines made up of multiple proteins that change the physical structure of chromatin and, thus, suppress or enable the activity of genes in a programmatic manner.

In recent years, her lab’s focus has centered on a family of complexes known as mammalian SWI/SNF chromatin remodeling complexes – commonly referred to as BAF complexes – which have garnered significant attention due to their disruption and involvement in human disease. BAF complexes are one of the most frequently mutated cellular entities in human cancer, second only to TP53, a well-studied tumor suppressor gene. Studies have shown that approximately 20 percent of human cancers bear BAF complex mutations and that such disruptions are also among the most common in neurodevelopmental disorders (NDDs) such as autism and intellectual disability.

The encounter between Neanderthals and Sapiens as told by their genomes

analysed the distribution of the portion of DNA inherited from Neanderthals in the genomes of humans (Homo sapiens) over the last 40,000 years.
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Image Credit: © Claudio Quilodrán

About 40,000 years ago, Neanderthals, who had lived for hundreds of thousands of years in the western part of the Eurasian continent, gave way to Homo sapiens, who had arrived from Africa. This replacement was not sudden, and the two species coexisted for a few millennia, resulting in the integration of Neanderthal DNA into the genome of Sapiens. Researchers at the University of Geneva (UNIGE) have analyzed the distribution of the portion of DNA inherited from Neanderthals in the genomes of humans (Homo sapiens) over the last 40,000 years. These statistical analyses revealed subtle variations in time and geographical space. This work, published in the journal Science Advances, helps us to understand the common history of these two species. 

Thanks to genome sequencing and comparative analysis, it is established that Neanderthals and Sapiens interbred and that these encounters were sometimes fruitful, leading to the presence of about 2% of DNA of Neanderthal origin in present-day Eurasians. However, this percentage varies slightly between regions of Eurasia, since DNA from Neanderthals is somewhat more abundant in the genomes of Asian populations than in those of European populations.