. Scientific Frontline

Tuesday, November 1, 2022

As dense as it gets: New Model for Matter in Neutron Star Collisions

Illustration of the new method: the researchers use five-dimensional black holes (right) to calculate the phase diagram of strongly coupled matter (middle), enabling simulations of neutron star mergers and the produced gravitational waves (left).
Source/Credit: Goethe University

With the exception of black holes, neutron stars are the densest objects in our universe. As their name suggests, neutron stars are mainly made of neutrons. However, our knowledge about the matter produced during the collision of two neutron stars is still limited. Scientists from Goethe University Frankfurt and the Asia Pacific Center for Theoretical Physics in Pohang have now developed a new model that gives insights about matter under such extreme conditions.

After a massive star has burned its fuel and explodes as a supernova, an extremely compact object, called a neutron star, can be formed. Neutron stars are extraordinarily dense: To reach the density inside them, one would need to squeeze a massive body like our sun down to the size of a city like Frankfurt. In 2017, gravitational waves, the small ripples in spacetime that are produced during a collision of two neutron stars, could be directly measured here on earth for the first time. However, the composition of the resulting hot and dense merger product is not known precisely. It is still an open question, for instance, whether quarks, which are otherwise trapped in neutrons, can appear in free form after the collision. Dr. Christian Ecker from the Institute for Theoretical Physics of Goethe University Frankfurt, Germany, and Dr. Matti Järvinen and Dr. Tuna Demircik from the Asia Pacific Center for Theoretical Physics in Pohang, South Korea, have now developed a new model that allows them to get one step closer to answering this question.

Learning to Better Understand the Language of Algae

A view through the microscope onto the diverse microalgal community of a freshwater lake, including diatoms, green algae and dinoflagellates/chryosphytes.
Photo: Maria Stockenreiter /LMU München

Communication is everything - and that applies for algae, too. However, their chemical language and its significance in aquatic ecosystems remain largely unknown. A research duo from the Helmholtz Centre for Environmental research (UFZ) and the Plymouth Marine Laboratory (PML) have published a corresponding review in Biological Reviews. This summarizes the current state of knowledge and identifies new approaches for future research in the language of algae and their ecological relationships.

Can algae talk? "Well, although they don't have any mouth or ears, algae still communicate with their own kind and with other organisms in their surroundings. They do this with volatile organic substances they release into the water," says Dr. Patrick Fink, a water ecologist at the UFZ's Magdeburg site. These chemical signals are known as BVOCs (biogenic volatile organic compounds) and are the equivalent of odors in the air with which flowering plants communicate and attract their pollinators. When under attack by parasites, some plant species release odors that attract the parasites' natural enemies to them. "Algae also employ such interactions and protective mechanisms," says Fink. "After all, they are among the oldest organisms on Earth, and chemical communication is the most original form of exchanging information in evolutionary history. However, our knowledge in this area still remains very fragmentary."

New Technique Helps ID Genes Related to Aging

The head of a C. elegans showing fluorescently labeled protein aggregates.
Source: North Carolina State University

Researchers from North Carolina State University have developed a new method for determining which genes are relevant to the aging process. The work was done in an animal species widely used as a model for genetic and biological research, but the finding has broader applications for research into the genetics of aging.

“There are a lot of genes out there that we still don’t know what they do, particularly in regard to aging,” says Adriana San Miguel, corresponding author of a paper on the work and an assistant professor of chemical and biomolecular engineering at NC State. “That’s because this field faces a very specific technical challenge: by the time you know whether an organism is going to live for a long time, it’s old and no longer able to reproduce. But the techniques we use to study genes require us to work with animals that are capable of reproducing, so we can study the role of specific genes in subsequent generations.

“To expedite research in this field, we wanted to find a way of identifying genes that may be relevant to aging while the organisms are still young enough to work with.”

For this work, the researchers focused on a species of roundworm called C. elegans, which is one of the most important model species for research into genetics and aging. Specifically, the researchers focused on protein aggregation in cells, which is well established as being related to aging.

Pancreatic cancer could be diagnosed up to three years earlier

The desmoplastic reaction is a prominent pathological characteristic of pancreatic cancer. 
Credit: National Cancer Institute

Pancreatic cancer could be identified in patients up to three years earlier than current diagnoses, new research suggests. Weight loss and increasing blood glucose levels are early indicators of pancreatic cancer and could lead to a timelier diagnosis, helping to improve survival rates.

In the largest study of its kind, researchers from the University of Oxford, in partnership with Pancreatic Cancer Action and the University of Surrey, investigated signs of pancreatic cancer, including weight loss, hyperglycemia and diabetes and demonstrated the timelines for when they develop in relation to cancer. The pancreas is a vital organ with two key functions, to produce insulin and digestive enzymes. Cancer can affect one or both of these functions leading to the above symptoms. Currently, almost 90 per cent of people with pancreatic cancer are diagnosed too late for curative treatment.

Lead author Dr Agnieszka Lemanska, Lecturer in Data Science at the University of Surrey, said: 'Due to the difficulty in detecting pancreatic cancer, survival rates are extremely poor compared to other cancers, with less than 10 per cent of people surviving five years or more after diagnosis.

'Weight loss and increased blood glucose are recognized symptoms of pancreatic cancer. However, the extent of these symptoms and when they manifest have been unknown. Knowing when they develop will help clinicians to diagnose this deadly cancer, meaning treatment can begin earlier.'

Physicists Proposed Theory of Solidification of Nickel and Iron Alloys

Nickel-iron alloy is used when high dimensional stability of finished parts is required.
Photo: unsplash.com / Laura Ockel

Physicists at Ural Federal University have created a theory for the solidification of a nickel-iron alloy (invar). They determined that an important role in the technology of creating products from invar, namely in the solidification process, is played by the oncoming flow: when the alloy cools, the liquid layer flows on top of the solidified layer. If you regulate this process, you can control the characteristics of the alloys, obtain a more homogeneous structure, thereby improving the properties of the final product.

The work of scientists is extremely important because nickel and iron alloys are used in creating high-precision devices: clocks, seismic sensors, substrates for chips, valves and engines in aircraft structures, and instruments for telescopes. The calculations will help to create an alloy with the desired structure, which will affect the quality of the finished products. Description of the model and behavior of melts, as well as analytical calculations, scientists have published in the journal Scientific Reports. The research was supported by the Russian Science Foundation (Project No. 21-79-10012).

"Let me explain the work with an analogy. When water freezes, it pushes out all the dirt. So, you can put a piece of ice in your mouth, it will be clean. This is roughly what happens to melts when they cool. The only difference is that they do not push out all the impurities, but some of them. Some of the impurities leak out, and some of the impurities stay in the melt. What remains in the melt fills the gaps between the crystals, which solidify, and the voids, which remain. As a result, the alloys are heterogeneous: one tiny piece is enriched and the neighboring piece is not. This affects the properties of the finished product," says Dmitry Aleksandrov, Head of the Ural Federal University's Laboratory of Multi-Scale Mathematical Modeling.

Habitat mapping data can fill gaps in knowledge on biodiversity

Dry sand heaths are also among the biotopes found in Hamburg.
Photo Credit: Christiane Buchwald

Data gathered by habitat mapping programs can make important contributions to biodiversity research. They provide insight into changes of the local flora since the 1980s – a period that is covered by hardly any other sources of information. A team from the Martin Luther University Halle-Wittenberg and the Hamburg Authorities for the Environment, Climate, Energy and Agriculture has now shown how research can benefit from this historic habitat mapping data using habitat maps of the city and federal state of Hamburg as an example. Their results, which have been published in "Ecosphere", also show a clear decline of species-rich habitats due to urbanization over the last decades.

In Germany, habitat mapping programs (Biotopkartierungen) have been carried out in almost every federal state since the 1980s. Similar sources exist in many other European countries. "The mapping programs are carried out by the authorities to obtain an overview of natural and semi-natural habitats for landscape planning and nature conservation," says Lina Lüttgert from the Institute of Biology of MLU. These datasets contain comprehensive data on all habitats of the local flora and fauna. Often, they also include information on the plant species found in these areas. This makes the data interesting for research: "They can provide insight into the changes over the last decades. Also, we do not have any other systematic surveys on local diversity from that period," says Lüttgert.

Better understanding of the development of intestinal diseases

Dr. Bahtiyar Yilmaz, First author
Department for BioMedical Research, University of Bern, and Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital
Credit:  zvg / Courtesy of Bahtiyar Yilmaz

Bacteria in the small intestine adapt dynamically to our nutritional state, with individual species disappearing and reappearing. Researchers at the University of Bern and University Hospital Bern have now been able to comprehensively study the bacteria of the small intestine and their unique adaptability for the first time. The findings contribute to a better understanding of intestinal diseases such as Crohn's disease or celiac disease and to the development of new therapeutic approaches.

Humans have just as many microbes in their microbiota as there are cells in the body, and most of these are in the large intestine (colon). They are an important part of our ‘digestion’ because they can harvest energy from many foods that evade our digestive enzymes. Unfortunately, whilst it is easy to collect fecal samples, it has been largely impossible to study the lower small intestine because this can only be reached during a surgical operation or after purging the intestinal contents to allow safe passage of an endoscope.

The small intestinal microbiome has remained almost “terra incognita” within the human gastrointestinal tract, despite the fact that the small intestine is essential for life and it absorbs 90% of all our calories. Researchers led by Andrew Macpherson and Bahtiyar Yilmaz from the Department for Biomedical Research at the University of Bern and the University Clinic for Visceral Surgery and Medicine at the Inselspital have now been able to examine the intestinal bacteria of the human small intestine in a simple and innovative way to show how they support the digestive process by reacting dynamically to the human nutritional status. While the gut bacteria (microbiota) of the large intestine remain relatively stable throughout life, those in the small intestine have been shown to be very unstable: they largely disappear when we fast overnight and reappear when we eat in the morning. These findings are important for a better understanding of the development of intestinal diseases such as celiac disease or Crohn's disease. The study is published in the journal Cell Host and Microbe.

‘A silent killer’ - COVID-19 shown to trigger inflammation in the brain

A COVID-19 infected mouse brain showing 'angry' microglia in green and SARS-CoV-2 in red.
Source/Credit: University of Queensland

Research led by The University of Queensland has found COVID-19 activates the same inflammatory response in the brain as Parkinson’s disease.

The discovery identified a potential future risk for neurodegenerative conditions in people who’ve had COVID-19, but also a possible treatment.

The UQ team was led by Professor Trent Woodruff and Dr Eduardo Albornoz Balmaceda from UQ’s School of Biomedical Sciences, and virologists from the School of Chemistry and Molecular Biosciences.

“We studied the effect of the virus on the brain’s immune cells, ‘microglia’ which are the key cells involved in the progression of brain diseases like Parkinson’s and Alzheimer’s,” Professor Woodruff said.

“Our team grew human microglia in the laboratory and infected the cells with SARS-CoV-2, the virus that causes COVID-19.

“We found the cells effectively became ‘angry’, activating the same pathway that Parkinson’s and Alzheimer’s proteins can activate in disease, the inflammasomes.”

Violent supershear earthquakes are more common than previously thought

A section of the San Andreas Fault between Bakersfield and Santa Barbara, California. UCLA’s Lingsen Meng said the reason relatively few supershear earthquakes were reported previously is that researchers tended not to count those that occur underwater.
Photo Credit: Carol M. Highsmith/Library of Congress 

Powerful supershear earthquakes, once considered rare, are much more common than previously thought, according to a study led by UCLA geophysicists and published in Nature Geoscience.

The scientists analyzed all 6.7-or-greater magnitude strike-slip earthquakes worldwide since 2000 — there were 87 in all — and identified 12 of the supershear type, or about 14%. (Four of those earthquakes were previously unreported.)

That percentage is more than double what scientists expected; until now less than 6% of strike-slip earthquakes had been identified as supershear.

Strike-slip earthquakes occur when the edges of two tectonic plates rub sideways against each other. Supershear quakes are a subtype of that group that are caused when faults beneath the surface rupture faster than shear waves — the seismic waves that shake the ground back and forth — can move through rock. The effect corrals energy that is then released violently; the effect can be compared to a sonic boom.

As a result, supershear earthquakes tend to cause more shaking, and are potentially more destructive, than other earthquakes that have the same magnitude.

Durable, Inexpensive Catalyst Reduces Carbon Footprint of Ammonia Production

To reduce the energy requirements of the Haber-Bosch process, which converts nitrogen and hydrogen to ammonia, researchers from Tokyo Tech have developed a metal nitride catalyst containing an active metal (Ni) on a lanthanum nitride support that is stable in presence of moisture. Since the catalyst doesn't contain ruthenium, it presents an inexpensive option for reducing the carbon footprint of ammonia production.

The Haber-Bosch process, which is commonly used to synthesize ammonia (NH3)–the foundation for synthetic nitrogen fertilizers–by combining hydrogen (H2) and nitrogen (N2) over catalysts at high pressures and temperatures, is one of the most important scientific discoveries that has helped improve crop yields and increase food production globally.

However, the process requires high fossil fuel energy inputs due to its requirements of high temperatures and pressure. Hydrogen used for this process is produced from natural gas (mainly methane). This hydrogen-producing process is energy-consuming and accompanies huge emissions of carbon dioxide. To overcome these issues, various catalysts have been developed to allow the reaction to proceed under milder conditions using hydrogen produced by water electrolysis via renewable energy. Among them are nitride-based catalysts that contain active metal nanoparticles like nickel and cobalt (Ni, Co) loaded on lanthanum nitride (LaN) supports. In these catalysts, both the support and the active metal are involved in the production of NH3. The active metal splits the H2 while the LaN support contains nitrogen vacancies and nitrogen atoms in its crystal structure that absorb and activate nitrogen (N2). While these catalysts are inexpensive (since they avoid using ruthenium, which is costly), their catalytic performance is degraded in the presence of moisture, with the LaN support transforming into lanthanum hydroxide (La(OH)3).

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