. Scientific Frontline: February 2024

Thursday, February 29, 2024

Lake Ecosystems: Nitrogen has been underestimated

Algae growth in shallow lakes around the world is affected not only by phosphorus but also by nitrogen
Photo Credit: Liz Harrell

An ecological imbalance in a lake can usually be attributed to increased nutrient inputs. The result: increased phytoplankton growth, oxygen deficiency, toxic cyanobacterial blooms and fish kills. Until now, controls in lake management have focused primarily on phosphorus inputs to counteract this effect. Now, this dogma is shaken by a study performed by the Helmholtz Centre for Environmental Research (UFZ) in collaboration with the University of Aarhus (Denmark) and the University of Life Sciences (Estonia) and published in Nature Communications. The researchers show that nitrogen is also a critical driver for phytoplankton growth in lakes worldwide. 

The input of phosphorus and nitrogen from agricultural sources and sewage treatment plants can have a strong effect on phytoplankton growth in rivers and lakes. "However, it was previously assumed that phytoplankton growth in lakes is mostly limited and driven by the availability of phosphorus," says lead author Dr. Daniel Graeber from the UFZ. The underlying theory: If only small quantities of phosphorus are available in a lake, phytoplankton growth is correspondingly limited. In contrast, large quantities of phosphorus will massively drive phytoplankton growth. "In this explanatory model, nitrogen plays no role," says Graeber. "This is based on the fact that specific cyanobacteria in the water can bind the nitrogen contained in the air and introduce it into the lake. This would therefore preclude a long-term nitrogen deficiency in lakes." Nor could an excess supply of nitrogen promote phytoplankton growth - and therefore could not ultimately give rise to eutrophication. "This model forms the basis for lake management worldwide, where the emphasis has been on controlling phosphorus inputs to counteract lake eutrophication," explains Dr. Thomas A. Davidson, limnologist at Aarhus University and last author of the study. "Reducing phosphorus inputs repeatedly fails to prevent eutrophication. This therefore gave rise to the question of whether the water equation included yet another unknown." In its present study, the research team has now clearly identified nitrogen as such a factor, and is thus indicating new directions for inland water science (limnology) and lake management. 

Oregon State University researchers are first to see at-risk bat flying over open ocean

Hoary bat at sea.
Photo Credit: Courtesy of Will Kennerley / the MOSAIC Project.

On a research cruise focused on marine mammals and seabirds, Oregon State University scientists earned an unexpected bonus: The first-ever documented sighting of a hoary bat flying over the open ocean.

The bat was seen in the Humboldt Wind Energy Area about 30 miles off the northern California coast; the Humboldt area has been leased for potential offshore energy development, and the hoary bat is the species of bat most frequently found dead at wind power facilities on land.

OSU faculty research assistant Will Kennerley, the first to see the bat, and colleagues documented the sighting with a paper in the Journal of North American Bat Research. The bat was spotted just after 1 p.m. on Oct. 3, 2022, in observing conditions rated as excellent.

“I have spent a lot of time at sea in all oceans of the world, and I’ve seen a lot of amazing things,” said Lisa Ballance, director of OSU’s Marine Mammal Institute. “A hoary bat was a first for all of us. It’s a reminder of the wonder of nature, and of its vulnerability.”

Scientists develop novel RNA- or DNA-based substances to protect plants from viruses

The new active ingredients can be used to protect plants against viruses.
Photo Credit: Uni Halle / Markus Scholz

Individually tailored RNA or DNA-based molecules are able to reliably fight off viral infections in plants, according to a new study by the Martin Luther University Halle-Wittenberg (MLU), which was published in the International Journal of Molecular Sciences. The researchers were able to fend off a common virus using the new active substances in up to 90 per cent of cases. They also developed a method for finding substances tailored specifically to the virus. The team has now patented the method.

During a viral infection, the plant’s cells are hijacked by the virus to multiply itself. Key products of this process are viral RNA molecules that serve as blueprints for the production of proteins. "A virus cannot reproduce without producing its proteins," explains Professor Sven-Erik Behrens from the Institute of Biochemistry and Biotechnology at MLU. For years, his team has been working on ways to disrupt this process and degrade the viral RNA molecules inside the cells. 

In the new study, the researchers describe how this can be achieved using the so-called "antisense" method. It relies on short, synthetically produced DNA molecules known as antisense oligonucleotides (ASOs). In the plant cells, the ASOs direct cellular enzymes acting as scissors towards the foreign RNA so they can degrade it. "For this process to work, it is crucial to identify a suitable target structure in the viral RNA which the enzyme scissors can attach to," explains Behrens. However, finding those accessible sites is really tricky: most potential target RNA molecules have a very complex structure, and they are also masked by other cell components. "This makes it even more difficult to attack them directly," says Behrens. 

Wednesday, February 28, 2024

Study finds drought fuels invasive species after wildfires

Parry’s Phacelia, native to Southern California, grows beneath burnt brush, at the Loma Ridge site where UCI’s Sarah Kimball conducted the research.
Photo Credit: Jessica Rath / UCI

In a study recently published in the journal Ecology, University of California, Irvine scientists uncover the intricate dance between drought, wildfires and invasive species in Southern California’s coastal sage scrub ecosystems.

Titled “Long-term drought promotes invasive species by reducing wildfire severity,” the research, led by Sarah Kimball, Ph.D., director of the Center for Environmental Biology at UCI, sheds light on the critical interplay of these factors and its profound implications for ecosystem health.

The research, conducted at the Loma Ridge Global Change Experiment, showcases how prolonged drought acts as a catalyst, influencing not only the severity of wildfires but also paving the way for invasive species to take center stage. By simulating drought conditions, the study clarifies connections between climate change, wildfire dynamics, and shifts in plant communities.

Reduced fire severity associated with drought creates an environment conducive to invasive species. Non-native grasses, in particular, thrive in these conditions, potentially leading to a transformation of the landscape and abundance and diversity of native species.

A step toward personalized immunotherapy for all

This immunofluorescence image shows CD4+ (green) and CD8+ (yellow) T cells in the microenvironment of a head and neck squamous cell carcinoma.
Image Credit: Allen Lab, NCI/NIH.

Most cancers are thought to evade the immune system. These cancers don’t carry very many mutations, and they aren’t infiltrated by cancer-fighting immune cells. Scientists call these cancers immunologically “cold.”

Now new research suggests such cancers aren’t as “cold” as once thought. Researchers from the La Jolla Institute for Immunology (LJI), UC San Diego Moores Cancer Center, and UC San Diego, have found that patients with “cold” tumors actually do make cancer-fighting T cells.

This discovery opens the door to developing vaccines or therapies to increase T cell numbers and treat many more types of cancer than currently thought possible.

“In virtually every patient we’ve looked at, with every kind of cancer we’ve analyzed, we can detect pre-existing natural immunity against their tumor’s immunogenic subset of mutations known as neoantigens,” says LJI Professor Stephen Schoenberger, Ph.D., who co-led the new study with LJI Professor Bjoern Peters, Ph.D. “Therefore, we think these patients may actually benefit from empowering this response through personalized immunotherapy.”

“Every cancer patient is different,” adds Peters. “But this research is an important step toward finding immune cell targets relevant for individual patient tumors.”

Aerial surveys reveal ample populations of rays in southeast Florida

The giant manta ray is designated as threatened under the U.S. Endangered Species Act and is protected in Florida waters.
Photo Credit: Steve Kajiura, Florida Atlantic University

The whitespotted eagle ray (Aetobatus narinari) and the giant manta ray (Mobula birostris) are rapidly declining globally. Both species are classified by the International Union for Conservation of Nature as endangered worldwide and the giant manta ray is designated as threatened under the United States Endangered Species Act.

In Florida waters, giant manta rays and whitespotted eagle rays are protected species. To provide effective management for these species, it is necessary to gather information on their distribution and abundance.

Using aerial surveys, Florida Atlantic University researchers conducted a unique long-term (2014 to 2021) study to quantify the spatial (latitude) and temporal (month, year) abundance of the whitespotted eagle rays and giant manta rays in Southeast Florida. The researchers conducted 120 survey flights between January 2014 and December 2021 along the Atlantic Coast from Miami north to the Jupiter Inlet. They reviewed the video footage from the flights to quantify the number of rays of each species.

80 mph speed record for glacier fracture helps reveal the physics of ice sheet collapse

In this illustration, seawater flows deep below the surface into an actively opening ice shelf rift in Antarctica. New research shows that such rifts can open very quickly, and that the seawater rushing in helps control the speed of ice shelf breakage.
Illustration Credit: Rob Soto

There’s enough water frozen in Greenland and Antarctic glaciers that if they melted, global seas would rise by many feet. What will happen to these glaciers over the coming decades is the biggest unknown in the future of rising seas, partly because glacier fracture physics is not yet fully understood.

A critical question is how warmer oceans might cause glaciers to break apart more quickly. University of Washington researchers have demonstrated the fastest-known large-scale breakage along an Antarctic ice shelf. The study, recently published in AGU Advances, shows that a 6.5-mile (10.5 kilometer) crack formed in 2012 on Pine Island Glacier — a retreating ice shelf that holds back the larger West Antarctic ice sheet — in about 5 and a half minutes. That means the rift opened at about 115 feet (35 meters) per second, or about 80 miles per hour.

“This is to our knowledge the fastest rift-opening event that’s ever been observed,” said lead author Stephanie Olinger, who did the work as part of her doctoral research at the UW and Harvard University and is now a postdoctoral researcher at Stanford University. “This shows that under certain circumstances, an ice shelf can shatter. It tells us we need to look out for this type of behavior in the future, and it informs how we might go about describing these fractures in large-scale ice sheet models.”

Neurons help flush waste out of brain during sleep

Researchers at Washington University School of Medicine in St. Louis have found that brain cell activity during sleep is responsible for propelling fluid into, through and out of the brain, cleaning it of debris.
Image Credit: Scientific Frontline stock image.

There lies a paradox in sleep. Its apparent tranquility juxtaposes with the brain’s bustling activity. The night is still, but the brain is far from dormant. During sleep, brain cells produce bursts of electrical pulses that cumulate into rhythmic waves — a sign of heightened brain cell function.

But why is the brain active when we are resting?

Slow brain waves are associated with restful, refreshing sleep. And now, scientists at Washington University School of Medicine in St. Louis has found that brain waves help flush waste out of the brain during sleep. Individual nerve cells coordinate to produce rhythmic waves that propel fluid through dense brain tissue, washing the tissue in the process.

“These neurons are miniature pumps. Synchronized neural activity powers fluid flow and removal of debris from the brain,” explained first author Li-Feng Jiang-Xie, a postdoctoral research associate in the Department of Pathology & Immunology. “If we can build on this process, there is the possibility of delaying or even preventing neurological diseases, including Alzheimer’s and Parkinson’s disease, in which excess waste — such as metabolic waste and junk proteins — accumulate in the brain and lead to neurodegeneration.”

Pancreatic cancer lives on mucus

A cross-section of a mouse’s early-stage pancreatic tumor. CSHL scientists discovered that early pancreatic cancer cells depend on the regulators of mucus production to survive and grow. Green, purple, yellow, cyan, and white denote areas where mucus production is high.
Image Credit: Cold Spring Harbor Laboratory

Knowing exactly what’s inside a tumor can maximize our ability to fight cancer. But that knowledge doesn’t come easy. Tumors are clusters of constantly changing cancer cells. Some become common cancer variants. Others morph into deadlier, drug-resistant varieties. No one truly understands what governs this chaotic behavior.

Now, Cold Spring Harbor Laboratory (CSHL) Professor David Tuveson and his team have uncovered a mechanism involved in pancreatic cancer transformation—mucus. During the disease’s early stage, pancreatic cancer cells produce mucus. Additionally, these cells depend on the body’s regulators of mucus production. This new knowledge could help set the stage for future diagnostic or therapeutic strategies.

The unpredictable, shifting nature of tumors makes it challenging to pinpoint the right treatments for patients. “We need to better understand this concept of cell plasticity and design therapy that takes this into consideration,” says Claudia Tonelli, a research investigator in the Tuveson lab, who led the study.

Light stimulates a new twist for synthetic chemistry

The molecules synthesized in this study form different isomers when irradiated with blue light.
Photo Credit: Akira Katsuyama

Molecules that are induced by light to rotate bulky groups around central bonds could be developed into photo-activated bioactive systems, molecular switches, and more.

Researchers at Hokkaido University, led by Assistant Professor Akira Katsuyama and Professor Satoshi Ichikawa at the Faculty of Pharmaceutical Sciences, have extended the toolkit of synthetic chemistry by making a new category of molecules that can be induced to undergo an internal rotation on interaction with light. Similar processes are believed to be important in some natural biological systems. Synthetic versions might be exploited to perform photochemical switching functions in molecular computing and sensing technologies, or in bioactive molecules including drugs. They report their findings in Nature Chemistry.

“Achieving a system like ours has been a significant challenge in photochemistry,” says Katsuyama. “The work makes an important contribution to an emerging field in molecular manipulation.”

Insights into the possibilities for light to significantly alter molecular conformations have come from examining some natural proteins. These include the rhodopsin molecules in the retina of the eye, which play a crucial role in converting light into the electrical signals that create our sense of vision in the brain. Details are emerging of how the absorption of light energy can induce a twisting rearrangement of part of the rhodopsin molecule, required for it to perform its biological function.

“Mimicking this in synthetic systems might create molecular-level switches with a variety of potential applications,” Katsuyama explains.

Study unlocks nanoscale secrets for designing next-generation solar cells

A team of MIT researchers and several other institutions has revealed ways to optimize efficiency and better control degradation, by engineering the nanoscale structure of perovskite devices. Team members include Madeleine Laitz, left, and lead author Dane deQuilettes.
Photo Credit: Courtesy of the researchers

Perovskites, a broad class of compounds with a particular kind of crystal structure, have long been seen as a promising alternative or supplement to today’s silicon or cadmium telluride solar panels. They could be far more lightweight and inexpensive, and could be coated onto virtually any substrate, including paper or flexible plastic that could be rolled up for easy transport.

In their efficiency at converting sunlight to electricity, perovskites are becoming comparable to silicon, whose manufacture still requires long, complex, and energy-intensive processes. One big remaining drawback is longevity: They tend to break down in a matter of months to years, while silicon solar panels can last more than two decades. And their efficiency over large module areas still lags behind silicon. Now, a team of researchers at MIT and several other institutions has revealed ways to optimize efficiency and better control degradation, by engineering the nanoscale structure of perovskite devices.

The study reveals new insights on how to make high-efficiency perovskite solar cells, and also provides new directions for engineers working to bring these solar cells to the commercial marketplace. The work is described today in the journal Nature Energy, in a paper by Dane deQuilettes, a recent MIT postdoc who is now co-founder and chief science officer of the MIT spinout Optigon, along with MIT professors Vladimir Bulovic and Moungi Bawendi, and 10 others at MIT and in Washington state, the U.K., and Korea.

“Ten years ago, if you had asked us what would be the ultimate solution to the rapid development of solar technologies, the answer would have been something that works as well as silicon but whose manufacturing is much simpler,” Bulovic says. “And before we knew it, the field of perovskite photovoltaics appeared. They were as efficient as silicon, and they were as easy to paint on as it is to paint on a piece of paper. The result was tremendous excitement in the field.”

New Fish Species Discovered at Remote Islands Off Mexico’s Pacific Coast

Two females of the newly discovered species, Halichoeres sanchezi or the tailspot wrasse. The males are larger and have different coloration.
Photo Credit: Allison & Carlos Estape

A team of scientists including Ben Frable of UC San Diego’s Scripps Institution of Oceanography have discovered a new species of tropical fish during an expedition to the remote islands of the Revillagigedo Archipelago off Mexico’s Pacific coast. The fish is likely endemic to these islands, meaning it is found no place else on Earth. The Revillagigedos are sometimes called the “Mexican Galapagos” for their trove of marine biodiversity and rugged beauty. 

The researchers describe the new species, dubbed Halichoeres sanchezi or the tailspot wrasse, in a paper published Feb. 28 in the journal PeerJ. Halichoeres sanchezi was named in honor of marine scientist Carlos Armando Sánchez Ortíz of the Universidad Autónoma de Baja California Sur (UABCS) who collected the first specimen and who organized the 2022 expedition that led to the fish’s discovery.

The eight specimens of the new species collected by the team range in size from around an inch long to nearly six inches. The smaller females of the species are mostly white with reddish horizontal stripes along their top half and black patches on their dorsal fin, behind their gills, and just ahead of their tail fin. Frable described the males as “orangy red up top fading to a yellow belly with a dark band at the base of the tail.” 

Halichoeres sanchezi is a member of the wrasse family, a highly diverse and colorful group of more than 600 species. Most wrasse are less than seven inches long, such as the bluestreak cleaner wrasse (Labroides dimidiatus), but some get much larger like the California sheephead (Semicossyphus pulcher) or the massive humphead wrasse (Cheilinus undulatus), which can reach seven feet in length.

Researchers encountered the new wrasse species inhabiting an underwater field of volcanic rubble at a depth of around 70 feet near San Benedicto Island.

Sikorsky Looks to Future Family of VTOL Systems

Hybrid-electric demonstrator will test electrification and autonomy for next-gen products
Photo Credit: Lockheed Martin

Sikorsky, a Lockheed Martin company, today unveiled its plan to build, test and fly a hybrid-electric vertical takeoff and landing demonstrator (HEX / VTOL) with a tilt-wing configuration.

The design is the first in a series of large, next generation VTOL aircraft — ranging from more traditional helicopters to winged configurations — which will feature varying degrees of electrification, and an advanced autonomy system for optionally piloted flight.

“We never stop innovating at Sikorsky,” said Sikorsky President Paul Lemmo. “Autonomy and electrification will bring transformational change to flight safety and operational efficiency of large VTOL aircraft. Our HEX demonstrator program will provide valuable insights as we look to a future family of aircraft built to the scale and preferred configurations relevant to commercial and military customers.”

The HEX program will put a premium on greater than 500 nautical mile range at high speed, fewer mechanical systems to reduce complexity, and lower maintenance costs.

Scientists provide first detailed estimates of how much sediment is supplied to coral islands from the reef system

The island of Dhigelabadhoo in the Maldives is the main field site of the ARISE program
Credit: University of Plymouth

Scientists have produced the first detailed estimates of how much sediment is transported onto the shores of coral reef islands, and how that might enable them to withstand the future threats posed by climate change.

Coral reef islands are low-lying accumulations of sand and gravel-sized sediment deposited on coral reef surfaces.

The sediments are derived from the broken down remains of corals and other organisms that grow on the surrounding reef. Therefore, the rate of supply of sediment from reefs is a critical control on island formation and future change.

The international team of researchers used data available for 28 reef islands in the Indian and Pacific Oceans, widely acknowledged to be among the world’s most vulnerable environments to rising seas.

By identifying the amount of sediment present within reef islands, and comparing this against the known age of the islands, they were able to determine the average amount of sediment delivered to the islands from surrounding coral reefs over their histories.

Biomolecules from Formaldehyde on Ancient Mars

Diagram showing the formation of formaldehyde (H2CO) in the warm atmosphere of ancient Mars and its conversion into molecules vital for life in the ocean.
Illustration Credit: ©Shungo Koyama

Organic materials discovered on Mars may have originated from atmospheric formaldehyde, according to new research, marking a step forward in our understanding of the possibility of past life on the Red Planet.

Scientists from Tohoku University have investigated whether the early atmospheric conditions on Mars had the potential to foster the formation of biomolecules - organic compounds essential for biological processes. Their findings, published in Scientific Reports, offer intriguing insights into the plausibility of Mars harboring life in its distant past.

Today, Mars presents a harsh environment characterized by dryness and extreme cold, but geological evidence hints at a more hospitable past. About 3.8-3.6 billion years ago, the planet probably had a temperate climate, sustained by the warming properties of gases like hydrogen. In such an environment, Mars may have had liquid water, a key ingredient for life as we know it.

Diamonds are a chip's best friend

Highly precise optical absorption spectra of diamond reveal ultra-fine splitting
Illustration Credit: KyotoU/Nobuko Naka

Besides being "a girl's best friend," diamonds have broad industrial applications, such as in solid-state electronics. New technologies aim to produce high-purity synthetic crystals that become excellent semiconductors when doped with impurities as electron donors or acceptors of other elements.

These extra electrons -- or holes -- do not participate in atomic bonding but sometimes bind to excitons -- quasi-particles consisting of an electron and an electron hole -- in semiconductors and other condensed matter. Doping may cause physical changes, but how the exciton complex -- a bound state of two positively-charged holes and one negatively-charged electron -- manifests in diamonds doped with boron has remained unconfirmed. Two conflicting interpretations exist of the exciton's structure.

An international team of researchers led by Kyoto University has now determined the magnitude of the spin-orbit interaction in acceptor-bound excitons in a semiconductor.

"We broke through the energy resolution limit of conventional luminescence measurements by directly observing the fine structure of bound excitons in boron-doped blue diamond, using optical absorption," says team leader Nobuko Naka of KyotoU's Graduate School of Science.

Tuesday, February 27, 2024

Walleye struggle with changes to timing of spring thaw

Within a few days of ice-off, when a lakes’ frozen lid has melted away, walleye begin laying eggs and fertilizing them. When lakes thaw earlier than usual, the young walleye that hatch in Midwestern waters may have a more difficult time surviving.
Image Credit: Copilot AI

Walleye are one of the most sought-after species in freshwater sportfishing, a delicacy on Midwestern menus and a critically important part of the culture of many Indigenous communities. They are also struggling to survive in the warming waters of the Midwestern United States and Canada.

According to a new study published in the journal Limnology and Oceanography Letters, part of the problem is that walleye are creatures of habit, and the seasons — especially winter — are changing so fast that this iconic species of freshwater fish can’t keep up.

The timing of walleye spawning — when the fish mate and lay their eggs — has historically been tied to the thawing of frozen lakes each spring, says the study’s lead author, Martha Barta, a research technician at the University of Wisconsin–Madison. Now, due to our changing climate, walleye have been “unable to keep up with increasingly early and more variable ice-off dates,” Barta says.

Within a few days of ice-off, when a lakes’ frozen lid has melted away, walleye begin laying eggs and fertilizing them. In a normal year, that timing sets baby fish up for success once they hatch. But, Barta says, “climate change is interrupting the historical pairing of ice-off and walleye spawning, and that threatens the persistence of walleye populations across the Upper Midwest.”

You may be breathing in more tiny nanoparticles from your gas stove than from car exhaust

Brandon Boor, a Purdue associate professor of civil engineering, studies how everyday activities like cooking on a gas stove can affect indoor air quality.
Photo Credit: Kelsey Lefever / Purdue University

Cooking on your gas stove can emit more nano-sized particles into the air than vehicles that run on gas or diesel, possibly increasing your risk of developing asthma or other respiratory illnesses, a new Purdue University study has found.

“Combustion remains a source of air pollution across the world, both indoors and outdoors. We found that cooking on your gas stove produces large amounts of small nanoparticles that get into your respiratory system and deposit efficiently,” said Brandon Boor, an associate professor in Purdue’s Lyles School of Civil Engineering, who led this research.

Based on these findings, the researchers would encourage turning on a kitchen exhaust fan while cooking on a gas stove. 

The study, published in the journal PNAS Nexus, focused on tiny airborne nanoparticles that are only 1-3 nanometers in diameter, which is just the right size for reaching certain parts of the respiratory system and spreading to other organs. 

Recent studies have found that children who live in homes with gas stoves are more likely to develop asthma. But not much is known about how particles smaller than 3 nanometers, called nanocluster aerosol, grow and spread indoors because they’re very difficult to measure.

“These super tiny nanoparticles are so small that you’re not able to see them. They’re not like dust particles that you would see floating in the air,” Boor said. “After observing such high concentrations of nanocluster aerosol during gas cooking, we can’t ignore these nano-sized particles anymore.”

Glacier melting destroys important climate data archive

Corbassière glacier at Grand Combin in the canton of Valais
Photo Credit: Peter Meyer-Herzog

As part of the Ice Memory initiative, PSI researchers, with colleagues from the University of Fribourg and Ca’ Foscari University of Venice as well as the Institute of Polar Sciences of the Italian National Research Council (CNR), analyzed ice cores drilled in 2018 and 2020 from the Corbassière glacier at Grand Combin in the canton of Valais. A comparison of the two sets of ice cores published in Nature Geoscience shows: Global warming has made at least this glacier unusable as a climate archive.

Reliable information about the past climate and air pollution can no longer be obtained from the Corbassière glacier in the Grand Combin massif, because alpine glacier melting is progressing more rapidly than previously assumed. This sobering conclusion was reached by researchers led by Margit Schwikowski, head of the Laboratory for Environmental Chemistry at PSI, and Carla Huber, PhD student and first author of the study, when they compared the signatures of particulate matter locked in the annual layers of the ice. Glaciers are invaluable for climate research. The climatic conditions and atmospheric compositions of past ages are preserved in their ice. Therefore, they can serve, in much the same way as tree rings and ocean sediments, as a so-called climate archive for research.

Normally, the amount of particle-bound trace substances in ice fluctuates with the seasons. SubstPeter Meyer-Herzogances such as ammonium, nitrate, and sulfate come from the air and are deposited on the glacier through snowfall: The concentrations are high in summer and low in winter, because lower amounts of polluted air can rise from the valley when the air is cold. The 2018 ice core, which was drilled from depths of up to 14 meters during a preliminary study and contains deposits dating back to 2011, shows these fluctuations as expected. But the core from 2020, from a depth of up to 18 metres – drilled under the leadership of PSI researcher Theo Jenk – shows those fluctuations only for the upper three or four annual layers. Deeper in the ice – that is, farther in the past – the curve indicating the concentration of trace substances becomes noticeably flatter, and the total amount is lower. Schwikowski’s team reports on this in the current issue of the journal Nature Geoscience.

Vital Seagrasses in Gulf of Mexico Are Retreating Amid Rapid Sea Level Rise

Marine Science professor Ken Dunton (left) and doctoral student Kyle Capistrant-Fossa (right) in the Gulf of Mexico.
Photo Credit: Courtesy of University of Texas at Austin

The Gulf of Mexico is experiencing sea level rise two to three times as fast as the global average due to a combination of warmer waters and wind circulation patterns. Now, a newly released long-term study from marine scientists at The University of Texas at Austin has found rising sea levels can be linked to a loss of valuable seagrass habitats in Texas.

The paper appears in Communications Earth & Environment.

Seagrasses are recognized globally as a foundation species that play a key role in supporting fisheries and mitigating climate change, efficiently storing substantial amounts of carbon. Meadows occur in shallow waters, and the species are dependent on light for photosynthesis and growth. The researchers are the first to find that sea level rise is yet another human impact that is responsible for the worldwide decline in seagrasses.

Ken Dunton, a professor in UT’s Marine Science Institute, and Kyle Capistrant-Fossa, a doctoral student, made the discovery while examining a 30-year database of observations that Dunton had collected at his study site in the Laguna Madre next to Padre Island. Capistrant-Fossa found that the slow loss of vegetation at the site during the past decade was also coincident with an unprecedented rise in sea level. They also found that seagrasses were disappearing from their historical deeper water ranges throughout the Upper Laguna Madre. But they noted that these losses could be compensated by plant expansion into areas that were once too shallow.

Bariatric surgery provides long-term blood glucose control, type 2 diabetes remission

Photo Credit: Fernando Zhiminaicela

NIH-supported study shows long-term benefits of surgery compared to medication and lifestyle change.

People with type 2 diabetes who underwent bariatric surgery achieved better long-term blood glucose control compared to people who received medical management plus lifestyle interventions, according to a new study supported by the National Institutes of Health. The participants who underwent bariatric surgery, also called metabolic or weight-loss surgery, were also more likely to stop needing diabetes medications and had higher rates of diabetes remission up to 12 years post-surgery. Results of the study were published in JAMA and funded by the National institute of Diabetes, Digestive and Kidney Diseases (NIDDK), part of NIH.

“While there are many factors involved, and not all of them are completely understood, bariatric surgery typically results in greater weight loss that effects a person’s metabolic hormones, which improves the body’s response to insulin and ability to maintain healthy blood glucose levels,” said Dr. Jean Lawrence, NIDDK project scientist. “These results show that people with overweight or obesity and type 2 diabetes can make long-term, improvements in their health and change the trajectory of their diabetes through surgery.”

Significant glacial retreat in West Antarctica began in 1940s

Thwaites Glacier from above.
Photo Credit: Ted Scambos.

A new study, involving researchers from British Antarctic Survey, has found that significant thinning and retreat of the vast Thwaites Glacier began in the 1940s.

Accelerating ice loss has been observed since the 1970s, but its unclear when this significant melting initiated – until now. These results coincide with previous work that found the Pine Island Glacier also began its retreat at this time. Climate models indicate that anthropogenic warming has increasingly driven West Antarctic ice loss since that time, and has prevented these glaciers from recovering.

James Smith, a marine geologist at British Antarctic Survey said:

“Our previous work in 2016 provided the first direct evidence that neighbouring Pine Island Glacier started to retreat in the 1940s. However, that was just one glacier draining into the huge Amundsen Sea Embayment. Now that we know Thwaites glacier also started to retreat around the same time is really significant. It demonstrates that glaciers in this area were responding synchronously to an external climatic driver.”

“A significant implication of our findings is that once an ice sheet retreat is set in motion it can continue for decades, even if what started it gets no worse. It is possible that the changes we see today on Thwaites and Pine Island glaciers – and potentially across the entire Amundsen Sea Embayment – were essentially set in motion in the 1940s.”

Merons realized in synthetic antiferromagnets

Direct observation of antiferromagnetic merons and antimerons
Illustration Credit: Mona Bhukta

Researchers in Germany and Japan have been able for the first time to identify collective topological spin structures called merons in layered synthetic antiferromagnets

The electronic devices we use on a day-to-day basis are powered by electrical currents. This is the case with our living room lights, washing machines, and televisions, to name but a few examples. Data processing in computers also relies on information provided by tiny charge carriers called electrons. The field of spintronics, however, employs a different concept. Instead of the charge of electrons, the spintronic approach is to exploit their magnetic moment, in other words, their spin, to store and process information – aiming to make the computers of the future more compact, fast, and sustainable. One way of processing information based on this approach is to use the magnetic vortices called skyrmions or, alternatively, their still little understood and rarer cousins called 'merons'. Both are collective topological structures formed of numerous individual spins. Merons have to date only been observed in natural antiferromagnets, where they are difficult to both analyze and manipulate.

New quantum entangled material could pave way for ultrathin quantum technologies

Artistic illustration depicts heavy-fermion Kondo matter in a monolayer material.
Illustration Credit: Adolfo Fumega/Aalto University

Researchers reveal the microscopic nature of the quantum entangled state of a new monolayer van der Waals material

Two-dimensional quantum materials provide a unique platform for new quantum technologies, because they offer the flexibility of combining different monolayers featuring radically distinct quantum states. Different two-dimensional materials can provide building blocks with features like superconductivity, magnetism, and topological matter. But so far, creating a monolayer of heavy-fermion Kondo matter – a state of matter dominated by quantum entanglement – has eluded scientists. Now, researchers at Aalto University have shown that it’s theoretically possible for heavy-fermion Kondo matter to appear in a monolayer material, and they’ve described the microscopic interactions that produces its unconventional behavior. These findings were published in Nano Letters.

“Heavy-fermion materials are promising candidates to discover unconventional topological superconductivity, a potential building block for quantum computers robust to noise,” says Adolfo Fumega, the first author of the paper and a post-doctoral researcher at Aalto University.

These materials can feature two phases: one analogous to a conventional magnet, and one where the state of the system is dominated by quantum entanglement, known as the heavy-fermion Kondo state. At the transition between the magnetic phase and the heavy-fermion state, macroscopic quantum fluctuations appear, leading to exotic states of matter including unconventional superconducting phases.

Out of the desert, a quantum powerhouse rises

Postdoctoral researcher Caitlin McCowan inspects pieces of silicon at the atomic level. She uses a scanning tunneling microscope to spot imperfections as part of a quantum research project at Sandia National Laboratories.
Photo Credit: Craig Fritz

They knew it was an ambitious goal. But by the time they announced it in 2022, Sandia National Laboratories and The University of New Mexico — two of the state’s largest research institutions — had been working out their strategy for more than a year.

Their goal: transform the state into a global powerhouse in the emerging quantum technology market. Success would mean the arrival of tech companies and startups, jobs and investments — an economic resurgence for the southwestern state.

The plan is picking up steam.

In January, Sandia and UNM created the Quantum New Mexico Institute, a cooperatively run research center headquartered at the university. This marks a major milestone in the comprehensive strategy to advance research, court businesses and train a quantum-ready workforce.

“Our vision is to make New Mexico a destination for quantum companies and scientists across the world,” said Setso Metodi, institute co-director and Sandia manager of quantum computer science.

‘Janitors’ of the Sea: Overharvested Sea Cucumbers Play Crucial Role in Protecting Coral

Photo Credit: Cody Clements

Corals are foundational for ocean life. Known as the rainforests of the sea, they create habitats for 25% of all marine organisms, despite only covering less than 1% of the ocean’s area. 

Coral patches the width and height of basketball arenas, used to be common throughout the world’s oceans. But due to numerous human-generated stresses and coral disease, which is known to be associated with ocean sediments, most of the world’s coral is gone.

“It’s like if all the pine trees in Georgia disappeared over a period of 30 to 40 years,” said Mark Hay, Regents’ Chair and the Harry and Anna Teasley Chair in Environmental Biology in the School of Biological Sciences at the Georgia Institute of Technology. “Just imagine how that affects biodiversity and ecosystems of the ocean.”

In first-of-its-kind research, Hay, along with research scientist Cody Clements, discovered a crucial missing element that plays a profound role in keeping coral healthy — an animal of overlooked importance known as a sea cucumber.

Study Offers Improved Look at Earth’s Ionosphere

Radio signal plasma wave from a parallel magnetic field. This animation shows the Faraday rotation phenomena in black. The grid at the end of the propagation path is the antenna, and the black line shows how the plane of polarization of the radio signal projects onto it.
Image Credit: E. Jensen/PSI.

New measuring techniques will enable improved measurements of the Earth’s ionosphere, a key to studying and reducing the impact of space weather.

Radio signals have been used to study the density of plasma since the 1920s. Transmitting radio sources include ground-based ionosondes (special radar for the examination of the ionosphere), astronomical phenomena such as pulsars and more recently spacecraft signals used for transmitting data. For example, Global Positioning Satellites (GPS) radio signals are used to measure the density of Earth’s ionosphere. However, the response of the radio signal to the ionospheric plasma is more complicated than simply varying as a function of density. The Earth’s magnetic field affects its electromagnetic wave fluctuations as well. For example, Faraday rotation is a well-known phenomenon, as shown in the image above. But, as a technique for measuring magnetic field, Faraday rotation is limited to just the portion that is oriented in the correct direction. Our discovery complements Faraday rotation enabling a complete measurement of magnetic field strength.

Modern hydropower plants also cause massive damage to ecology

Water samples collected by TUM researchers
Photo Credit: Lehrstuhl für Aquatische Systembiologie / TUM

Even modern and supposedly gentler hydropower plants cause considerable damage to river ecosystems. This is shown by a study by Prof. Jürgen Geist from the Chair of Aquatic Systems Biology at the TUM School of Life Sciences published in the Journal of Applied Ecology. Geist and his team investigated the changes in the complex biocoenoses in rivers at five locations in Bavaria before and after the installation of hydropower plants. They looked not only at fish but also at microorganisms, aquatic plants, and algae growth.

Significant differences in living conditions were observed at all locations, emphasizes Geist. This applies to the situation upstream and downstream of the power plants as well as before and after installation. "Contrary to what was hoped for and predicted by the operators, the new types of power plant have not improved the habitat conditions for current-loving species," the biologist states. In particular, retrofitting existing weirs in conjunction with further damming would have negative effects.

"When planning future plants, in addition to the question of the sometimes-considerable damage to fish when passing through hydropower plants, the previously neglected effects on the habitat and the food web must also be taken into account. This is about the ecological continuity and connection of different river sections as an important criterion for healthy river systems," said Geist. The requirements are defined in the EU Water Framework Directive.

Immune system meets cancer: Checkpoint identified to fight solid tumor

Immunofluorescence image of the expression of PHGDH (red) and CD3 T cells (green) in cryosectioned AE17 mesothelioma.
Image Credit: Zhengnan Cai

Checkpoint PHDGH in tumor-associated macrophages influences immune response and tumor growth

A study by a scientific team from the University of Vienna and the MedUni Vienna, recently published in the top-class journal Cellular & Molecular Immunology, has a promising result from tumor research: The enzyme phosphoglycerate dehydrogenase (PHDGH) acts as a metabolic checkpoint in the function of tumor-associated macrophages (TAMs) and thus on tumor growth. Targeting PHGDH to modulate the cancer-fighting immune system could be a new starting point in cancer treatment and improve the effectiveness of clinical immunotherapies.

Our immune system constantly fights emerging cancer cells that arise from mutations. This process is controlled, among other things, by different types of macrophages. Tumor-associated macrophages (TAMs) are among the most abundant immune cells in the tumor microenvironment. They come from tissue-resident immune cells circulating in the blood that penetrate the tumor and differentiate there in response to various messenger substances (cytokines) and growth factors. In most solid tumors, TAMs are paradoxically considered to be tumor-promoting ("protumorigenic") overall: they promote tumor growth and metastasis by suppressing the immune response, promoting the vascular supply to the tumor and also increasing resistance to drug therapies – i.e. they generally correlate with a poor prognosis for the affected patients. Previous attempts to influence TAMs proved unsatisfactory because many patients had only a limited response to these therapeutic approaches. This underlines the urgency of finding new active ingredients and strategies.

Monday, February 26, 2024

Gut-brain communication turned on its axis

How the gut communicates with the brain
Image Credit: Copilot AI

The mechanisms by which antidepressants and other emotion-focused medications work could be reconsidered due to an important new breakthrough in the understanding of how the gut communicates with the brain.

New research led by Flinders University has uncovered major developments in understanding how the gut communicates with the brain, which could have a profound impact on the make-up and use of medications such as antidepressants.

“The gut-brain axis consists of complex bidirectional neural communication pathway between the brain and the gut, which links emotional and cognitive centers of the brain,” says Professor Nick Spencer from the College of Medicine and Public Health.

“As part of the gut-brain axis, vagal sensory nerves relay a variety of signals from the gut to the brain that play an important role in mental health and wellbeing.

“The mechanisms by which vagal sensory nerve endings in the gut wall are activated has been a major mystery but remains of great interest to medical science and potential treatments for mental health and wellbeing.”

Human stem cells coaxed to mimic the very early central nervous system

Jianping Fu, Ph.D., Professor of Mechanical Engineering at the University of Michigan and the corresponding author of the paper being published at Nature discusses his team’s work in their lab with Jeyoon Bok, Ph.D. candidate at the Department of Mechanical Engineering.
Photo Credit: Marcin Szczepanski, Michigan Engineering

The first stem cell culture method that produces a full model of the early stages of the human central nervous system has been developed by a team of engineers and biologists at the University of Michigan, the Weizmann Institute of Science, and the University of Pennsylvania.

“Models like this will open doors for fundamental research to understand early development of the human central nervous system and how it could go wrong in different disorders,” said Jianping Fu, U-M professor of mechanical engineering and corresponding author of the study in Nature.

The system is an example of a 3D human organoid—stem cell cultures that reflect key structural and functional properties of human organ systems but are partial or otherwise imperfect copies.

“We try to understand not only the basic biology of human brain development, but also diseases—why we have brain-related diseases, their pathology, and how we can come up with effective strategies to treat them,” said Guo-Li Ming, who along with Hongjun Song, both Perelman Professors of Neuroscience at UPenn and co-authors of the study, developed protocols for growing and guiding the cells and characterized the structural and cellular characteristics of the model.

New study uncovers the importance of deepwater ecosystems for endangered species

Hawksbills typically forage on coral reefs where their diet is predominantly sponges.
Photo Credit: Jeanne A Mortimer

Using tracking data, a new study has revealed for the first time that hawksbill turtles feed at reef sites much deeper than previously thought.

Critically endangered hawksbill turtles are found in every ocean and are the most tropical of sea turtles. Adult hawksbills have long been considered to have a close association with shallow (less than 15 meters depth) seas where coral reefs thrive.

Young hawksbills drift in currents during their open water phase of their development before they move to seabed habitats. Hawksbills are usually seen foraging in coral reefs where their diet is predominantly sponges.

To study their feeding habits in more detail, researchers at Swansea, Florida and Deakin universities used high-accuracy GPS satellite tags to track 22 adult female hawksbills from their nesting site on Diego Garcia in the Chagos archipelago in the Indian Ocean to their foraging grounds.

Scientists develop biocompatible fluorescent spray that detects fingerprints in ten seconds

The researchers have made two different colored sprays, which detect fingerprints on a range of different surfaces.
Image Credit: Courtesy of University of Bath

Scientists have developed a water soluble, non-toxic fluorescent spray that makes fingerprints visible in just a few seconds, making forensic investigations safer, easier and quicker.

Latent fingerprints (LFPs) are invisible prints formed by sweat or oil left on an object after it’s been touched.

Traditional forensic methods for detecting fingerprints either use toxic powders that can harm DNA evidence, or environmentally damaging petrochemical solvents.

The new dye spray, developed by scientists at the Shanghai Normal University (China) and the University of Bath (UK), is water soluble, exhibits low toxicity and enables rapid visualization of fingerprints at the crime scene.

They have created two different colored dyes – called LFP-Yellow and LFP-Red – which bind selectively with the negatively-charged molecules found in fingerprints, locking the dye molecules in place and emitting a fluorescent glow that can be seen under blue light.

Vaping can increase susceptibility to infection by SARS-CoV-2

UC Riverside study urges e-cigarette users to be cautious about vaping in the era of COVID-19
Photo Credit: Karl Edwards

Vapers are susceptible to infection by SARS-CoV-2, the virus that spreads COVID-19 and continues to infect people around the world, a University of California, Riverside, study has found.

The liquid used in electronic cigarettes, called e-liquid, typically contains nicotine, propylene glycol, vegetable glycerin, and flavor chemicals. The researchers found propylene glycol/vegetable glycerin alone or along with nicotine enhanced COVID-19 infection through different mechanisms.  

The researchers also found that the addition of benzoic acid to e-liquids prevents the infection caused by propylene glycol, vegetable glycerin, and nicotine. 

“Users who vape aerosols produced from propylene glycol/vegetable glycerin alone or e-liquids with a neutral to basic pH are more likely to be infected by the virus, while users who vape aerosols made from e-liquids with benzoic acid — an acidic pH — will have the same viral susceptibility as individuals who do not vape,” said Rattapol Phandthong, a postdoctoral researcher in the Department of Molecular, Cell and Systems Biology and the research paper’s first author.

The researchers obtained airway stem cells from human donors to produce a 3D tissue model of human bronchial epithelium. They then exposed the tissues to JUUL and BLU electronic cigarette aerosols to study the effect on SARS-CoV-2 infection. They found all tissues showed an increase in the amount of ACE2, a host cell receptor for the SARS-CoV-2 virus. Further, TMPRSS2, an enzyme essential for the virus to infect cells, was found to show increased activity in tissues exposed to aerosols with nicotine.

Laser-focused look at spinning electrons shatters world record for precision

The Compton polarimeter’s laser system, used to measure the parallel spin of electrons, is aligned during the Calcium Radius Experiment at Jefferson Lab.
Photo Credit: Jefferson Lab /Dave Gaskell

Scientists are getting a more detailed look than ever before at the electrons they use in precision experiments.

Nuclear physicists with the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility have shattered a nearly 30-year-old record for the measurement of parallel spin within an electron beam – or electron beam polarimetry, for short. The achievement sets the stage for high-profile experiments at Jefferson Lab that could open the door to new physics discoveries.

In a peer-reviewed paper published in the journal Physical Review C, a collaboration of Jefferson Lab researchers and scientific users reported a measurement more precise than a benchmark achieved during the 1994-95 run of the SLAC Large Detector (SLD) experiment at the SLAC National Accelerator Laboratory in Menlo Park, California.

“No one has measured the polarization of an electron beam to this precision at any lab, anywhere in the world,” said Dave Gaskell, an experimental nuclear physicist at Jefferson Lab and a co-author on the paper. “That’s the headline here. This isn’t just a benchmark for Compton polarimetry, but for any electron polarization measurement technique.”

Compton polarimetry involves detecting photons – particles of light – scattered by charged particles, such as electrons. That scattering, aka the Compton effect, can be achieved by sending laser light and an electron beam on a collision course.

Electrons – and photons – carry a property called spin (which physicists measure as angular momentum). Like mass or electric charge, spin is an intrinsic property of the electron. When particles spin in the same direction at a given time, the quantity is known as polarization. And for physicists probing the heart of matter on the tiniest scales, knowledge of that polarization is crucial.

“Think of the electron beam as a tool that you're using to measure something, like a ruler,” said Mark Macrae Dalton, another Jefferson Lab physicist and co-author on the paper. “Is it in inches or is it in millimeters? You have to understand the ruler in order to understand any measurement. Otherwise, you can’t measure anything.”

Resurrecting niobium for quantum science

The Josephson junction is the information-processing heart of the superconducting qubit. Pictured here is the niobium Josephson junction engineered by David Schuster of Stanford University and his team. Their junction design has resurrected niobium as a viable option as a core qubit material.
Image Credit: Alexander Anferov/the University of Chicago’s Pritzker Nanofabrication Facility.

For years, niobium was considered an underperformer when it came to superconducting qubits. Now scientists supported by Q-NEXT have found a way to engineer a high-performing niobium-based qubit and so take advantage of niobium’s superior qualities.

When it comes to quantum technology, niobium is making a comeback.

For the past 15 years, niobium has been sitting on the bench after experiencing a few mediocre at-bats as a core qubit material.

Qubits are the fundamental components of quantum devices. One qubit type relies on superconductivity to process information.

Touted for its superior qualities as a superconductor, niobium was always a promising candidate for quantum technologies. But scientists found niobium difficult to engineer as a core qubit component, and so it was relegated to the second string on Team Superconducting Qubit.

Now, a group led by Stanford University’s David Schuster has demonstrated a way to create niobium-based qubits that rival the state-of-the-art for their class.

Metal scar found on cannibal star

This artist’s impression shows the magnetic white dwarf WD 0816-310, where astronomers have found a scar imprinted on its surface as a result of having ingested planetary debris.  When objects like planets or asteroids approach the white dwarf they get disrupted, forming a debris disc around the dead star. Some of this material can be devoured by the dwarf, leaving traces of certain chemical elements on its surface.   Using ESO’s Very Large Telescope, astronomers found that the signature of these chemical elements changed periodically as the star rotated, as did the magnetic field. This indicates that the magnetic fields funneled these elements onto the star, concentrating them at the magnetic poles and forming the scar seen here.
Illustration Credit: ESO/L. Calçada

When a star like our Sun reaches the end of its life, it can ingest the surrounding planets and asteroids that were born with it. Now, using the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile, researchers have found a unique signature of this process for the first time — a scar imprinted on the surface of a white dwarf star. The results are published today in The Astrophysical Journal Letters.

“It is well known that some white dwarfs — slowly cooling embers of stars like our Sun — are cannibalizing pieces of their planetary systems. Now we have discovered that the star’s magnetic field plays a key role in this process, resulting in a scar on the white dwarf’s surface,” says Stefano Bagnulo, an astronomer at Armagh Observatory and Planetarium in Northern Ireland, UK, and lead author of the study.

Study sheds light on how neurotransmitter receptors transport calcium, a process linked with origins of neurological disease

Illustration Credit: Courtesy of McGill University

A new study from a team of McGill University and Vanderbilt University researchers is shedding light on our understanding of the molecular origins of some forms of autism and intellectual disability.

For the first time, researchers were able to successfully capture atomic resolution images of the fast-moving ionotropic glutamate receptor (iGluR) as it transports calcium. iGluRs and their ability to transport calcium are vitally important for many brain functions such as vision or other information coming from sensory organs. Calcium also brings about changes in the signaling capacity of iGluRs and nerve connections which are a key cellular events that lead to our ability to learn new skills and form memories.

iGluRs are also key players in brain development and their dysfunction through genetic mutations has been shown to give rise to some forms of autism and intellectual disability. However, basic questions about how iGluRs trigger biochemical changes in the brain’s physiology by transporting calcium have remained poorly understood.

In the study, the researchers took millions of snapshots of the iGluR protein in the act of transporting calcium, and unexpectedly discovered a temporary pocket that traps calcium on the outside of the protein. With this information at hand, they then used high-resolution electrophysiological recordings to watch the protein in motion as it transported calcium into the nerve cell.

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