. Scientific Frontline

Wednesday, February 28, 2024

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
(CC BY-NC-ND 4.0 DEED)

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.

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