. Scientific Frontline

Monday, November 8, 2021

Microbiome discovery could help save kids’ hearing

Bacteria could help fight chronic middle ear infections.
Credit: Australian Department of Health
Bacteria found in children’s upper respiratory systems could help fight chronic middle ear infections, the leading cause of preventable hearing loss and deafness in Indigenous communities.

The University of Queensland’s Dr Seweryn Bialasiewicz said this discovery helped explain a long-held mystery, while providing hope for potential treatments.

“We’ve been puzzled for years now, trying to work out why some children never develop chronic ear disease, despite being in a high-risk category for contracting it,” Dr Bialasiewicz said.

“By focusing on the microbiomes in the upper respiratory tracts of disease-resistant kids, we could investigate the ecological networks of bacterial interactions that seemed to be working together to protect against the condition.

“It was clear that these two groups of bacteria needed to not only be present, but to be interacting with each other, to provide protection from middle ear infections.”

Dr Bialasiewicz said they were hoping to use this information to figure out what the exact mechanism of protection is, and then mimic it in the very young children, as a therapy or a preventative measure.

“This could take the form of a molecule that can be used as a drug for treatment, or as a protective probiotic so that these ‘good’ bacteria can be seeded in the nose early enough to offer protection against the incoming ‘bad’ bacteria,” he said.

First Global River Database Documents 40 Years of Change

A first-ever database compiling movement of the largest rivers in the world over time could become a crucial tool for urban planners to better understand the deltas that are home to these rivers and a large portion of Earth’s population.

The database, created by researchers at The University of Texas at Austin, uses publicly available remote sensing data to show how the river centerlines of the world’s 48 most threatened deltas have moved during the past 40 years. The data can be used to predict how rivers will continue to move over time and help governments manage population density and future development.

“When we think about river management strategies, we have very little to no information about how rivers are moving over time,” said Paola Passalacqua, an associate professor in the Cockrell School of Engineering’s Department of Civil, Architectural and Environmental Engineering who leads the ongoing river analysis research.

The research was published today in Proceedings of the National Academy of Sciences.

The database includes three U.S. rivers, the Mississippi, the Colorado and the Rio Grande. Although some areas of these deltas are experiencing migration, overall, they are mostly stable, the data show. Aggressive containment strategies to keep those rivers in their place, especially near population centers, play a role in that, Passalacqua said.

Scientists Issue New Climate Adaptation “Scorecard”

Beaver landscape mimicry project on Blackfeet Nation lands
Credit: Center for Large Landscape Conservation

A new study, co-authored by researchers at the Wildlife Conservation Society (WCS) and the University of British Columbia’s Faculty of Forestry, offers a “scorecard” for climate adaptation projects – a set of 16 criteria that can be used to evaluate climate adaptation projects and inform their design. The scientists recently published their findings in the journal Environmental Science & Policy.

Climate adaptation projects are interventions that help wildlife, ecosystems, and people adapt to climate change. Examples include restoring habitat with plant species that are more likely to survive future climate conditions, reclaiming agricultural lands to create erosion-resistant ecosystems, and installing artificial nests to foster more resilient habitat for birds.

The research team interviewed and surveyed 18 climate adaptation experts and then surveyed an additional 47 practitioners to develop this flexible and comprehensive set of criteria, which can be tailored to an individual project’s goals and context.

The increasingly significant and unprecedented pledges in investments for adaptation have intensified the need to assess adaptation outcomes and return on investment. However, unlike evaluating climate change mitigation outcomes, which scientists can measure through the balance of greenhouse gas emissions and removals, evaluating adaptation is a complex endeavor. Outcomes can be multifaceted, (social, ecological, economic), and may not be apparent for years after project completion, making it difficult to define what constitutes success and whether it was achieved.

Weak coupling shows flaw in strange metal model

Planckian metals have the potential to power high-temperature superconductors, quantum computers and a host of other next-generation technologies. However, these “strange” metals – in which electrical resistance increases linearly with temperature – are notoriously difficult to study, let alone comprehend.

In the last decade, physicists have attempted to explore the inner workings of these quantum materials with cold atom experiments, whereby the behavior of electrons is simulated with neutral atoms, light beams and ultra-cold temperatures. These 2D models provide an analog system that allows experimentalists to see the interactions at more scrutable length and time scales – microns and milliseconds, rather than angstroms and femtoseconds – bringing them ever closer to understanding the materials’ unusual electrical functions.

Now, Cornell researchers led by Erich Mueller, professor of physics in the College of Arts and Sciences, have found this experimental model doesn’t capture what’s really happening inside strange metals at all.

Their paper, “Transport in the Two-Dimensional Fermi-Hubbard Model: Lessons from Weak Coupling,” published Oct. 25 in Physical Review B. The lead author is doctoral student Thomas Kiely.

“These cold atom experiments are a really awesome way to try and learn about this strange metal behavior, this crazy unusual resistivity, which we believe is the key to understanding how to make higher-temperature superconductors and all sorts of other things,” Mueller said. “We found there’s actually a simple explanation for what happens in this experiment.”

Neutrons take a deep dive into water networks surrounding DNA

Vanderbilt University researchers used neutrons at ORNL to reveal the hydrogen bonding patterns between water molecules (shown in blue) and DNA. The findings could help provide insights into how water influences DNA function.
Credit: ORNL/Jill Hemman

Water plays several important roles within the human body, even affecting the DNA in our cells. The entire surface of a DNA double helix is coated in layers of water molecules. This sheath of water attaches to the genetic material through hydrogen bonds, made by sharing hydrogen atoms between molecules. Through hydrogen bonds, water can influence how DNA takes shape and interacts with other molecules. In some cases, water can help proteins recognize DNA sequences.

Scientists can estimate where hydrogen bonds occur and how hydrogen atoms are shared, but it is difficult to gather experimental evidence. A research team led by Vanderbilt University has used a method that successfully captured the most detailed view to date of water’s hydrogen bonding patterns around DNA, opening new possibilities for studying how water impacts DNA function. Details on the methodology and the results, produced in part through neutron scattering at the Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL), are published in the journal Nucleic Acids Research.

“Water serves as a mediator between DNA and other molecules, even for very specific interactions. Before any molecule can bind to a segment of DNA, it must first go through this water shell,” said Martin Egli, a biochemistry professor at Vanderbilt University and corresponding author of the study. “To advance our understanding of DNA processes, it’s important to know exactly what the surrounding water does and how it arranges itself around molecules.”

Converting Methane to Methanol -- With and Without Water

This scanning tunneling electron microscope image shows the structure of a copper-zinc oxide catalyst that converts methane to methanol with and without water. Triangular zinc-oxide "islands" rest on a copper-oxide thin film (flat background) over a copper substrate (not seen). The "step" edges between copper-oxide and zinc-oxide (A, where blue is zinc, red is oxygen) are the main active sites for producing methanol when no water is present. The semi-flat areas have a relatively perfect crystal structure (B) and are inert during the reaction. The very rough areas are likely associated with defects—in this case with fewer zinc atoms and an oxygen-rich crystal structure (C)—and are the most active sites for methanol production when water is present.
Credit: Brookhaven National Laboratory

Chemists have been searching for efficient catalysts to convert methane—a major component of abundant natural gas—into methanol, an easily transported liquid fuel and building block for making other valuable chemicals. Adding water to the reaction can address certain challenges, but it also complicates the process. Now a team at the U.S. Department of Energy’s Brookhaven National Laboratory has identified a new approach using a common industrial catalyst that can complete the conversion effectively both with and without water. The findings, published in the Journal of the American Chemical Society, suggest strategies for improving catalysts for the water-free conversion.

“Water is like a trick that people have been using for a long time to get this reaction going—and it definitely helps. It improves the selectivity and it aids the ability to extract the methanol,” said José Rodriguez, a leader of Brookhaven Lab’s Catalysis Group, who has an adjunct appointment at Stony Brook University (SBU) in the departments of Chemistry and Materials Science and Chemical Engineering.

As shown in a recent related study by this group, adding water keeps the reaction from running away to transform the desired product, methanol, into carbon monoxide (CO) and carbon dioxide (CO2). But adding water also adds complexity and cost. Plus, at the temperatures and in the amounts required for this reaction, the water exists as large quantities of steam, which would have to be controlled in an industrial setting.

So, the Brookhaven team set out to explore if they could run the reaction without water by changing the catalyst—the substance that brings the reactants together and helps guide them along a particular reaction pathway.

Time crystals in the limelight

An artist’s impression of a discrete time crystal composed of nine qubits represented by the nuclear spins of nine carbon-13 atoms in diamond. The chain of connected spins is locked in a phase where they periodically invert their states.
(Image by Joe Randall and Tim Taminiau, courtesy of QuTech)

UC Berkeley physicist Norman Yao first described five years ago how to make a time crystal — a new form of matter whose patterns repeat in time instead of space. Unlike crystals of emerald or ruby, however, those time crystals existed for only a fraction of a second.

But the time has arrived for time crystals. Since Yao’s original proposal, new insights have led to the discovery that time crystals come in many different forms, each stabilized by its own distinct mechanism.

Using new quantum computing architectures, several labs have come close to creating a many-body localized version of a time crystal, which uses disorder to keep periodically-driven quantum qubits in a continual state of subharmonic jiggling — the qubits oscillate, but only every other period of the drive.

In a paper published in the journal Science, Yao and colleagues at QuTech — a collaboration between Delft University of Technology and TNO, an independent research group in the Netherlands — reported the creation of a many-body localized discrete time crystal that lasted for about eight seconds, corresponding to 800 oscillation periods. They used a quantum computer based upon a diamond, where the qubits — quantum bits, the analog of binary bits in digital computers — are the nuclear spins of carbon-13 atoms embedded inside the diamond.

Healable carbon fiber composite offers path to long-lasting, sustainable materials

Because of their high strength and light weight, carbon-fiber-based composite materials are gradually replacing metals for advancing all kinds of products and applications, from airplanes to wind turbines to golf clubs. But there’s a trade-off. Once damaged or compromised, the most commonly-used carbon fiber materials are nearly impossible to repair or recycle.

In a paper published Nov. 2 in the journal Carbon, a team of researchers describes a new type of carbon fiber reinforced material that is as strong and light as traditionally used materials but can be repeatedly healed with heat, reversing any fatigue damage. This also provides a way to break it down and recycle it when it reaches the end of its life.

"Developing fatigue-resistant composites is a major need in the manufacturing community," said co-lead author Aniruddh Vashisth, University of Washington assistant professor of mechanical engineering. "In this paper, we demonstrate a material where either traditional heat sources or radio frequency heating can be used to reverse and postpone its aging process indefinitely."

The material is part of a recently developed group known as carbon fiber reinforced vitrimers, named after the Latin word for glass, that show a mix of solid and fluid properties. The materials typically used today, whether in sporting goods or aerospace, are carbon fiber reinforced polymers.

Black holes of ‘all shapes and sizes’ in new gravitational-wave catalog


An international team of researchers, including Northwestern University astrophysicists, has released the largest-ever catalog of gravitational-wave events.

Of the 35 new events observed between November 2019 and March 2020, 33 were likely mergers between black holes of various shapes and sizes. The other two events were likely black holes merging with neutron stars — a much rarer event. Of these rare black hole and neutron star mergers, one event appears to show a massive black hole (about 33 times the mass of our sun) merging with a very low-mass neutron star (about 1.17 times the mass of our sun). This is one of the lowest-mass neutron stars ever detected.

Since the first gravitational-wave detection in 2015, astrophysicists have detected a total of 90 events. By calculating the masses of the merging objects, astrophysicists can better understand how stars live and die and what makes them collapse into black holes versus neutron stars upon death.

Christopher Berry
“Only now are we starting to appreciate the wonderful diversity of black holes and neutron stars,” said Christopher Berry, a key member of the Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific Collaboration (LSC). “Our latest results prove that they come in many sizes and combinations. We have solved some long-standing mysteries but uncovered some new puzzles too. Using these observations, we are closer to unlocking the mysteries of how stars — the building blocks of our universe — evolve.”

The research is now available online, with two accompanying papers forthcoming. The team includes researchers from the LSC, the Virgo Collaboration and the Kamioka Gravitational Wave Detector (KAGRA) project.

An expert in gravitational-wave parameter estimation, Berry is a lecturer at the University of Glasgow

Friday, November 5, 2021

Shared origins of irritable bowel syndrome and mental health disorders

3D still showing Irritable bowel syndrome 
Credit: Scientific Animations
IBS is a common condition world-wide, affecting around 1 in 10 people and causing a wide range of symptoms including abdominal pain, bloating and bowel dysfunction that can significantly affect people’s lives. Diagnosis is usually made after considering other possible conditions (such as Crohn’s disease or bowel cancer), with clinical tests coming back ‘normal’. The condition often runs in families and is also more common among people who are prone to anxiety. The causes of IBS are not well understood, but an international team of researchers has now identified several genes that provide clues into the origins of IBS.

The research team, including more than 40 institutions and coordinated by scientists in UK and Spain, looked at genetic data from 40,548 people who suffer with IBS from the UK Biobank and 12,852 from the Bellygenes initiative (a world-wide study aiming to identify genes linked to IBS) and compared them to 433,201 people without IBS (controls), focusing on individuals of European ancestry. The findings were repeated with de-identified data from the genomics company 23andMe Inc., provided by customers who have consented to research, by comparing 205,252 people with IBS to 1,384,055 controls.

The results showed that overall, heritability of IBS (how much your genes influence the likelihood of developing a particular condition) is quite low, indicating the importance of environmental factors such as diet, stress and patterns of behavior that may also be shared in the family environment.

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