. Scientific Frontline

Wednesday, December 20, 2023

Scientists uncover link between the ocean’s weather and global climate

Oceanic weather systems (mesoscale eddies) from data overlaid with atmospherically driven climate-scale currents (black lines), which can be extracted with a coarse graining technique developed in the lab of Hussein Aluie. The image reveals how these ocean weather systems are energized (red) or weakened (blue) when interacting with climate-scales, which follows a pattern mirroring the global atmospheric circulation.
Illustration Credit: Benjamin Storer

Using mechanical rather than statistical analysis, the team offers a new framework for understanding the climate system.

An international team of scientists has found the first direct evidence linking seemingly random weather systems in the ocean with climate on a global scale. Led by Hussein Aluie, an associate professor in the University of Rochester’s Department of Mechanical Engineering and staff scientist at the University’s Laboratory for Laser Energetics, the team reported their findings in Science Advances.

The ocean has weather patterns like what we experience on land, but on different time and length scales, says lead author Benjamin Storer, a research associate in Aluie’s Turbulence and Complex Flow Group. A weather pattern on land might last a few days and be about 500 kilometers wide, while oceanic weather patterns such as swirling eddies last three to four weeks but are about one-fifth the size.

Cosmic lights in the forest

TACC’s Frontera, the fastest academic supercomputer in the US, is a strategic national capability computing system funded by the National Science Foundation.
Photo Credit: TACC.

Like a celestial beacon, distant quasars make the brightest light in the universe. They emit more light than our entire Milky Way galaxy. The light comes from matter ripped apart as it is swallowed by a supermassive black hole. Quasar light reveals clues about the large-scale structure of the universe as it shines through enormous clouds of neutral hydrogen gas formed shortly after the Big Bang on the scale of 20 million light years across or more. 

Using quasar light data, the National Science Foundation (NSF)-funded Frontera supercomputer at the Texas Advanced Computing Center (TACC) helped astronomers develop PRIYA, the largest suite of hydrodynamic simulations yet made for simulating large-scale structure in the universe.

“We’ve created a new simulation model to compare data that exists at the real universe,” said Simeon Bird, an assistant professor in astronomy at the University of California, Riverside. 

Bird and colleagues developed PRIYA, which takes optical light data from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey (SDSS). He and colleagues published their work announcing PRIYA in the Journal of Cosmology and Astroparticle Physics (JCAP). 

Research offers a reason why diversity in plant species causes higher farming yield, solving 'a bit of a mystery'

Co-author Peggy Schultz collects data on plots with undergraduate workers.
Photo Credit: KU Marketing

A study appearing in Nature Communications based on field and greenhouse experiments at the University of Kansas shows how a boost in agricultural yield comes from planting diverse crops rather than just one plant species: Soil pathogens harmful to plants have a harder time thriving.

“It’s commonly observed that diverse plant communities can be more productive and stable over time,” said corresponding author James Bever, senior scientist with the Kansas Biological Survey & Center for Ecological Research and Foundation Distinguished Professor of Ecology & Evolutionary Biology at KU. “Range lands with numerous species can show increased productivity. But the reason for this has been a bit of a mystery.”

While crop rotation and other farming and gardening practices long have reflected benefits of a mix of plants, the new research puts hard data to one important mechanism underpinning the observation: the numbers of microorganisms in the soil that eat plants.

“Diverse agricultural communities have the potential to keep pathogens at bay, resulting in greater yields,” Bever said. “What we show is that a major driver is the specialization of pathogens, particularly those specific to different plant species. These pathogens suppress yields in low-diversity communities. A significant advantage of rangeland diversity is that less biomass is consumed by pathogens, allowing more biomass for other uses, such as cattle. The same process is crucial for agricultural production.”

Aerogel can become the key to future terahertz technologies

Aerogel can obtain high hydrophobicity by simple chemical modifications.
Photo Credit: Thor Balkhed

High-frequency terahertz waves have great potential for a number of applications including next-generation medical imaging and communication. Researchers at Linköping University, Sweden, have shown, in a study published in the journal Advanced Science, that the transmission of terahertz light through an aerogel made of cellulose and a conducting polymer can be tuned. This is an important step to unlock more applications for terahertz waves.

The terahertz range covers wavelengths that lie between microwaves and infrared light on the electromagnetic spectrum. It has a very high frequency. Thanks to this, many researchers believe that the terahertz range has great potential for use in space exploration, security technology and communication systems, among other things. In medical imaging, it can also be an interesting substitute for X-ray examinations as the waves can pass through most non-conductive materials without damaging any tissue.

However, there are several technological barriers to overcome before terahertz signals can be widely used. For example, it is difficult to create terahertz radiation in an efficient way and materials that can receive and adjust the transmission of terahertz waves are needed.

Uncovering the role of beta diversity in ecosystems

Karen Castillioni observes beta diversity in a prairie habitat.
Photo Credit: College of Biological Sciences

As climate change progresses, scientists want to better understand how species interact across habitats to preserve diversity. Key to these efforts is the concept of beta diversity, which explores species that thrive exclusively in specific habitats. The University of Minnesota's Cedar Creek Ecosystem Science Reserve in East Bethel is an ideal place to study beta diversity because it gives researchers access to many distinct habitats in one place. 

Karen Castillioni, a postdoctoral research associate in the College of Biological Sciences, along with Associate Professor Forest Isbell, wanted to know how beta diversity affects plant biomass, the total mass of living plants in a given area. Plant biomass is crucial for various ecological and environmental functions, including carbon sequestration and supporting food webs.

During the first phase of an experiment at Cedar Creek called BetaDIV, the researchers looked at five habitats: oak savanna, where bur oak tree dominates; coniferous forest, where white pine dominates; deciduous forest, where red maple dominates; bog, where tamarack dominates; and an old grassland where big bluestem dominates.

An Electrifying Improvement in Copper Conductivity

Xiao Li, a materials scientist, holds samples of highly conductive metal wires created on the patented Shear Assisted Processing and Extrusion platform. 
Photo Credit: Andrea Starr | Pacific Northwest National Laboratory

A common carbon compound enables remarkable performance enhancements when mixed in just the right proportion with copper to make electrical wires. It’s a phenomenon that defies conventional wisdom about how metals conduct electricity. The findings, reported December 2023 in the journal Materials & Design, could lead to more efficient electricity distribution to homes and businesses, as well as more efficient motors to power electric vehicles and industrial equipment. The team has applied for a patent for the work, which was supported by the Department of Energy (DOE) Advanced Materials and Manufacturing Technologies Office.

Materials scientist Keerti Kappagantula and her colleagues at DOE’s Pacific Northwest National Laboratory discovered that graphene, single layers of the same graphite found in pencils, can enhance an important property of metals called the temperature coefficient of resistance. This property explains why metal wires get hot when electric current runs through them. Researchers want to reduce this resistance while enhancing a metal’s ability to conduct electricity. For several years they have been asking whether metal conductivity be increased, especially at high temperatures, by adding other materials to it. And if yes, can these composites be viable on a commercial scale?

Now, they’ve demonstrated they can do just that, using a PNNL-patented advanced manufacturing platform called ShAPE™. When the research team added 18 parts per million of graphene to electrical-grade copper, the temperature coefficient of resistance decreased by 11 percent without decreasing electrical conductivity at room temperature. This is relevant for the manufacturing of electric vehicle motors, where an 11 percent increase in electrical conductivity of copper wire winding translates into a 1 percent gain in motor efficiency.

Natto Consumption Suppresses Arteriosclerosis

Photo Credit: Seiya Maeda

Natto is widely recognized for inhibiting arteriosclerosis, yet its underlying mechanism remains elusive. Researchers led by the University of Tsukuba studied the effects of natto on arteriosclerosis in mice. The findings showed that consuming natto induced changes in the intestinal microflora, suppressing inflammation and preventing arteriosclerosis.

Atherosclerosis, a chronic condition characterized by the accumulation of lipid and inflammatory cells within the blood vessel walls, causes cardiovascular diseases, such as heart disease and stroke. Natto, a food rich in vitamin K2, has shown promise in mitigating cardiovascular diseases by enhancing arterial flexibility and modulating inflammatory responses. However, the reason why natto suppresses arteriosclerosis remains elusive.

Insects already had a variety of defense strategies in the Cretaceous

Larva of a wedge-shaped beetle in amber, which could have lived inside other insects like its modern counterparts. 
Image Credit: © Carolin Haug

Analyses of amber show that insect larvae were already using a wide variety of tactics to protect themselves from predators 100 million years ago.

Early life stages of insects fulfill important functions in our ecosystems. They decompose dead bodies and wood, forming soil and returning various elements into material cycles. Not least, they are a major food source for many larger animals such as birds and mammals. This has led to many insect larvae developing structures and strategies for reducing the danger of being eaten. These include features like spines and hairs, but also camouflage and concealment. Over millions of years, a wide variety of such adaptation strategies have developed.

Researchers at LMU and the universities of Greifswald and Rostock have studied particularly well-preserved fossils from Burmese amber and have been able to demonstrate that such anti-predator mechanisms had already evolved very diverse forms in insect larvae during the Cretaceous period 100 million years ago. This includes well-known strategies such as that employed by lacewing larvae, which carry various plant and animal materials on their back to give them camouflage, or the ploy of mimicking the appearance of certain plant parts.

Discovery: plants use “trojan horse” to fight mold invasions

Photo Credit: Gábor Adonyi

UC Riverside scientists have discovered a stealth molecular weapon that plants use to attack the cells of invading gray mold. 

If you’ve ever seen a fuzzy piece of fruit in your fridge, you’ve seen gray mold. It is an aggressive fungus that infects more than 1,400 different plant species: almost all fruits, vegetables, and many flowers. It is the second most damaging fungus for food crops in the world, causing billions in annual crop losses.

A new paper in the journal Cell Host & Microbe describes how plants send tiny, innocuous-seeming lipid “bubbles” filled with RNA across enemy lines, into the cells of the aggressive mold. Once inside, different types of RNA come out to suppress the infectious cells that sucked them in.

“Plants are not just sitting there doing nothing. They are trying to protect themselves from the mold, and now we have a better idea how they’re doing that,” said Hailing Jin, Microbiology & Plant Pathology Department professor at UCR and lead author of the new paper.

Previously, Jin’s team discovered that plants are using the bubbles, technically called extracellular vesicles, to send small RNA molecules able to silence genes that make the mold virulent. Now, the team has learned these bubbles can also contain messenger RNA, or mRNA, molecules that attack important cellular processes, including the functions of organelles in mold cells. 

Toxic chemicals found in oil spills and wildfire smoke detected in killer whales

Orcas (killer whales)
Photo Credit: Bart van Meele

Toxic chemicals produced from oil emissions and wildfire smoke have been found in muscle and liver samples from Southern Resident killer whales and Bigg’s killer whales.

A study published in Scientific Reports is the first to find polycyclic aromatic hydrocarbons (PAHs) in orcas off the coast of B.C., as well as in utero transfer of the chemicals from mother to fetus.

“Killer whales are iconic in the Pacific Northwest—important culturally, economically, ecologically and more. Because they are able to metabolically process PAHs, these are most likely recent exposures. Orcas are our canary in the coal mine for oceans, telling us how healthy our waters are,” said senior author Dr. Juan José Alava, principal investigator of the UBC Ocean Pollution Research Unit and adjunct professor at Simon Fraser University.

PAHs are a type of chemical found in coal, oil and gasoline which research suggests are carcinogenic, mutagenic, and have toxic effects on mammals. Their presence in the ocean comes from several sources, including oil spills, burning coal and forest fire smoke particles.

Researchers analyzed muscle and liver samples from six Bigg’s, or transient, killer whales and six Southern Resident killer whales (SRKWs) stranded in the northeastern Pacific Ocean between 2006 and 2018. They tested for 76 PAHs and found some in all samples, with half the PAHs appearing in at least 50 per cent of the samples. One compound, a PAH derivative called C3-phenanthrenes/anthracenes, accounted for 33 per cent of total contamination across all samples. These forms of PAHs, known as alkylated PAHs, are known to be more persistent, toxic, and to accumulate more in the bodies of organisms or animals than parental PAHs.

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