Zero Gravity Helps Create Homogeneous Material Structure

The mathematical model of the UrFU scientists helps to simulate the solidification process of an alloy. Credit: unsplash.com / Dan Cristian Pădureț

In space, due to the absence of gravity, metal hardens more homogeneously than on Earth. This was discovered by physicists who calculated the solidification process of aluminum-nickel metal alloys. Alloys were not chosen by chance, as they are one of the most common and account for 20% of all metalworking in the world. The model was built based on experimental data: the results obtained for alloy samples in microgravity on board the International Space Station were compared with the results of samples processed in terrestrial conditions. The results of experiments and modeling are presented in the journal Acta Materialia.

All aluminum-based materials are produced from the liquid phase, which is the initial phase. The solidification process and the conditions present at the moment of solidification determine the microstructural state of the final part, the scientists explain. The model considers the effects of crystallization rate and supercooling on the formation of alloy structure and properties, and allows the correct prediction of the microstructure and the required mechanical and electrical properties of the alloy.

Develop effective psychotherapies faster

Simon Blackwell of the Research and Treatment Center for Mental Health
Credit: Research and treatment center for mental health

The increasing number of mental illnesses is a growing problem for society. The development of psychotherapies on the traditional path cannot keep pace with this.

Researchers at the Ruhr University Bochum (RUB) asked themselves whether there could be a faster and more efficient way to develop and improve psychological interventions. In the journal "Psychological Medicine" they present the so-called Leapfrog design, with which various interventions can be compared efficiently without having to carry out several clinical studies one after the other. The Bochum team around Dr. Simon Blackwell together with a colleague of the Ludwig Maximilians University in Munich in the journal "Psychological Medicine", published online.

Adapted method from cancer research

"Clinical studies are mostly time consuming and inefficient," says Blackwell of the RUB's Research and Treatment Center for Mental Health. “You can take years and require hundreds of participants - and in the end it may turn out that the intervention tested is not effective. And even if the intervention were effective, it would probably be wanted to improve it again quickly, because in the meantime, for example, new relevant research data have been published. This in turn means that you have to plan and conduct another, probably even larger and more time-consuming clinical study."

A Microbe's Local Environment Can Be the Difference Between Life and Death

Co-cultures of bacterial strains that produce (magenta) or consume (cyan) nitric oxide show range-dependent growth and lead to single cell intermixing in the absence of oxygen. Scale bar represents 10 µm.
Credit: S. Wilbert

The microbial world shapes essentially every facet of our lives. Whether they are in the soils where our food is grown, or the lungs of a person with an infection, or at the bottom of the ocean, microbes live in diverse communities made up of multiple species all working together and impacting each other. Just like in our own neighborhoods, the geography of how a microbial community is laid out affects how those microbes live and function together.

Now, Caltech researchers have discovered that changes in local oxygen concentration have drastic impacts on whether microbial neighbors live or die in the presence of a common microbial by-product, nitric oxide (NO). The results suggest that large-scale global models, such as those of the nitrogen cycle, ought to work toward representing the fact that chemical microscale environments affect microbial behavior.

Call it a CRISPR conundrum

Model grass Brachypodium distachyon plant grown on liquid media.
Photo courtesy of Marta Torres, m-CAFEs postdoctoral researcher, Deutschbauer lab, Environmental Genomics and Systems Biology "
Credit: University of California, Lawrence Berkeley National Laboratory."

Bacteria use CRISPR-Cas systems as adaptive immune systems to withstand attacks from enemies like viruses. These systems have been adapted by scientists to remove or cut and replace specific genetic code sequences in a variety of organisms.

But in a new study, North Carolina State University researchers show that viruses engineered with a CRISPR-Cas system can thwart bacterial defenses and make selective changes to a targeted bacterium – even when other bacteria are in close proximity.

“Viruses are very good at delivering payloads. Here, we use a bacterial virus, a bacteriophage, to deliver CRISPR to bacteria, which is ironic because bacteria normally use CRISPR to kill viruses,” said Rodolphe Barrangou, the Todd R. Klaenhammer Distinguished Professor of Food, Bioprocessing and Nutrition Sciences at NC State and corresponding author of a paper describing the research published today in Proceedings of the National Academy of Sciences. “The virus in this case targets E. coli by delivering DNA to it. It’s like using a virus as a syringe.”

The NC State researchers deployed two different engineered bacteriophages to deliver CRISPR-Cas payloads for targeted editing of E. coli, first in a test tube and then within a synthetic soil environment created to mimic soil – a complex environment that can harbor many types of bacteria.

Designing Next-Generation Metals, One Atom at a Time

Pacific Northwest National Laboratory researchers are visualizing how shear forces rearrange metal atoms in ways that translate to improved characteristics—like greater strength, ductility, and conductivity—to inform the custom design of next-generation metals with broad applications from batteries to vehicles.   
Composite Credit: image by Shannon Colson | Pacific Northwest National Laboratory

How can studying metals manufacturing lead to longer-lasting batteries and lighter vehicles? It all comes down to physics.

Researchers at Pacific Northwest National Laboratory (PNNL) are investigating the effects of physical forces on metals by taking a direct look at atomic-level changes in metals undergoing shear deformation.

The forces applied during shear deformation to change a metal’s shape also rearrange its atoms, but not in the same way for every metal or alloy. Atomic arrangement can affect metal properties like strength, formability, and conductivity—so better understanding how atoms move during shear is a key part of ongoing efforts to custom design next-generation metals with specific properties from the atom up.

Scientists discover exotic quantum state at room temperature

Researchers at Princeton discovered a material, made from the elements bismuth and bromine, that allows specialized quantum behaviors — usually seen only under high pressures and temperatures near absolute zero — to appear at room temperature. 
Photo Credit: Shafayat Hossain and M. Zahid Hasan, Princeton University

For the first time, physicists have observed novel quantum effects in a topological insulator at room temperature. This finding opens up a new range of possibilities for the development of efficient quantum technologies, such as spin-based electronics, which may potentially replace many current electronic systems for higher energy efficiency.

The breakthrough, published as the cover article of the October issue of Nature Materials, came when Princeton scientists explored a topological material based on the element bismuth.

The scientists have used topological insulators to demonstrate quantum effects for more than a decade, but this experiment is the first time these effects have been observed at room temperature. Typically, inducing and observing quantum states in topological insulators requires temperatures around absolute zero, which is equal to minus 459 degrees Fahrenheit (or -273 degrees Celsius).

In recent years, the study of topological states of matter has attracted considerable attention among physicists and engineers and is presently the focus of much international interest and research. This area of study combines quantum physics with topology — a branch of theoretical mathematics that explores geometric properties that can be deformed but not intrinsically changed.

“The novel topological properties of matter have emerged as one of the most sought-after treasures in modern physics, both from a fundamental physics point of view and for finding potential applications in next-generation quantum engineering and nanotechnologies,” said M. Zahid Hasan, the Eugene Higgins Professor of Physics at Princeton University, led the research. “This work was enabled by multiple innovative experimental advances in our lab at Princeton.”

New international study concludes digital media can fuel polarization and populism

Image Credit: Thomas Ulrich

The question of whether the rise in usage of digital media is contributing to the erosion of democracy is a source of popular debate, with tech companies arguing the findings are inconclusive.

But now a team of international researchers has carried out a comprehensive review of hundreds of studies globally, the biggest of its kind, exploring this claim and found that while social media is not exclusively bad, it can certainly stoke starkly conflicting views, populism, and political mistrust especially in established democracies.

The researchers, from the Max Planck Institute for Human Development and the Hertie School in Germany, and the University of Bristol in the UK, systematically assessed studies investigating whether and how digital media impacts people’s political behavior. Studies show that although some effects may be beneficial for democracy, for instance digital media can increase political knowledge and diversity of news exposure, they also have detrimental effects, such as fostering polarization and populism.

Furthermore, the way consequences such as increased political mobilization and decreasing trust in institutions play out depends largely on the political context. Such developments were found to be beneficial in emerging democracies but can have destabilizing effects in established democracies.

Researchers develop superfast new method to manufacture high-performance thermoelectric devices

high-performance thermoelectric devices for energy harvesting and cooling
Source: University of Notre Dame

Yanliang Zhang, associate professor of aerospace and mechanical engineering at the University of Notre Dame, and collaborators Alexander Dowling and Tengfei Luo have developed a machine-learning assisted superfast new way to create high-performance, energy-saving thermoelectric devices.

The novel process uses intense pulsed light to sinter thermoelectric material in less than a second (conventional sintering in thermal ovens can take hours). The team sped up this method of turning nanoparticle inks into flexible devices by using machine learning to determine the optimum conditions for the ultrafast but complex sintering process.

The achievement was just published in the journal Energy and Environmental Science.

Flexible thermoelectric devices offer great opportunities for direct conversion of waste heat into electricity as well as solid-state refrigeration, Zhang said. They have additional benefits such as power sources and cooling devices — they don’t emit greenhouse gases, and they are durable and quiet since they don’t have moving parts.

Early planetary migration can explain missing planets

An illustration of the variations among the more than 5,000 known exoplanets discovered since the 1990s.
Image Credit: of NASA/JPL-Caltech

A new model that accounts for the interplay of forces acting on newborn planets can explain two puzzling observations that have cropped up repeatedly among the more than 3,800 planetary systems cataloged to date.

One puzzle known as the “radius valley” refers to the rarity of exoplanets with a radius about 1.8 times that of Earth. NASA’s Kepler spacecraft observed planets of this size about 2-3 times less frequently than it observed super-Earths with radii about 1.4 times that of Earth and mini-Neptunes with radii about 2.5 times Earth’s. The second mystery, known as “peas in a pod,” refers to neighboring planets of similar size that have been found in hundreds of planetary systems. Those include TRAPPIST-1 and Kepler-223, which also feature planetary orbits of near-musical harmony.

“I believe we are the first to explain the radius valley using a model of planet formation and dynamical evolution that self-consistently accounts for multiple constraints of observations,” said Rice University’s André Izidoro, corresponding author of a study published this week in Astrophysical Journal Letters. “We’re also able to show that a planet-formation model incorporating giant impacts is consistent with the peas-in-a-pod feature of exoplanets.”

University of Oxford study provides important insights into TB correlates of protection

Drug-resistant, Mycobacterium tuberculosis bacteria, the pathogen responsible for causing the disease tuberculosis (TB). A 3D computer-generated image.
Image Credit: CDC

Researchers from the University of Oxford have today reported findings from a study that investigated whether previously identified correlates of protection associated with risk of full-blown tuberculosis (TB) disease could also be associated with risk of infection from the bacteria that causes TB - highlighting certain correlates in the process.

In their paper on the TB020 study, published in Nature Communications, researchers identified that certain correlates of protection – inflammation and activation of the immune system (where the body responds to invading pathogens such as viruses and harmful bacteria) – were associated with the likelihood of becoming infected with Mycobacterium tuberculosis (M.tb), the bacteria that causes TB disease.

However, their previously identified correlates of risk of TB disease were not associated with an increased risk of M.tb infection in infants who became infected with the bacteria but did not progress to active TB.

Most individuals infected with M.tb do not progress to full TB disease. Instead, infection is either eliminated or contained by the infected individual. This study improves understanding of the immune-related factors that drive infection and disease – necessary for an effective TB vaccine that is yet to be developed.