New quantum phase discovered for developing hybrid materials

 Metropolitan University Scientists have discovered that in Ba1-xSrxAl2O4, a highly disordered atomic arrangement is formed in the AlO4 network at chemical compositions near the structural quantum critical point, resulting in both characteristics of crystalline and amorphous materials.
Illustration Credit: Yui Ishii, Osaka

Scientists discovered a hybrid state in which crystals exhibit both crystalline and amorphous characteristics near the structural quantum critical point.

If you have ever watched water freeze to ice, you have witnessed what physicists call a “phase transition.” Osaka Metropolitan University scientists have discovered an unprecedented phase transition during which crystals achieve amorphous characteristics while retaining their crystalline properties. Their findings contribute to developing hybrid materials for use in harsh environments, such as outer space. The results were published in Physical Review B.

A typical phase transition exhibited by crystalline solids involves a change in the crystal structure. Such structural phase transitions usually occur at finite temperatures. However, controlling the chemical composition of the crystal can lower the transition temperature to absolute zero (−273°C). The transition point at absolute zero is called the structural quantum critical point.

Old Bone Links Lost American Parrot to Ancient Indigenous Bird Trade

A thick-billed parrot.
Photo Credit: U.S. Fish and Wildlife.

For centuries, Indigenous communities in the American Southwest imported colorful parrots from Mexico. But according to a study led by The University of Texas at Austin, some parrots may have been captured locally and not brought from afar.

The research challenges the assumption that all parrot remains found in American Southwest archaeological sites have their origins in Mexico. It also presents an important reminder: The ecology of the past can be very different from what we see today.

“When we deal with natural history, we can constrain ourselves by relying on the present too much,” said the study’s author, John Moretti, a doctoral candidate at the UT Jackson School of Geosciences. “These bones can give us kind of a baseline view of the animal life of the ecosystems that surrounded us before huge fundamental changes that continue today began.”

The study was published in print in the September issue of The Wilson Journal of Ornithology.

Study shows differences between brains of primates — humans, apes and monkeys — are small but significant

Researchers analyzed genetic material from cells in the prefrontal cortex (the area shaded in each brain) from four closely-related primates to characterize subtle differences in cell type and genetics.
Source/Credit: University of Wisconsin–Madison

While the physical differences between humans and non-human primates are quite distinct, a new study reveals their brains may be remarkably similar. And yet, the smallest changes may make big differences in developmental and psychiatric disorders.

Understanding the molecular differences that make the human brain distinct can help researchers study disruptions in its development. A new study, published recently in the journal Science by a team including University of Wisconsin–Madison neuroscience professor Andre Sousa, investigates the differences and similarities of cells in the prefrontal cortex — the frontmost region of the brain, an area that plays a central role in higher cognitive functions — between humans and non-human primates such as chimpanzees, Rhesus macaques and marmosets.

The cellular differences between these species may illuminate steps in their evolution and how those differences can be implicated in disorders, such as autism and intellectual disabilities, seen in humans. Sousa, who studies the developmental biology of the brain at UW–Madison’s Waisman Center, decided to start by studying and categorizing the cells in the prefrontal cortex in partnership with the Yale University lab where he worked as a postdoctoral researcher.

There’s room for improvement in a popular climate-smart agricultural practice

The promise for American agriculture is tantalizing: healthier soil, more carbon kept in the ground, less fertilizer runoff, and less need for chemicals. The reality of planting cover crops during the off-season – a much-touted and subsidized approach to climate change mitigation – is more complicated, according to new Stanford University-led research. The study, published Nov. 8 in Global Change Biology, reveals that cover cropping as currently done in a major U.S. crop-growing region reduces corn and soybean yields, and could lead to indirect environmental impacts from expanded cultivation to make up for the losses.

“Use of cover crops is rapidly spreading. We wanted to see how these new practices affect crop yields in the real world, outside of small-scale research plots,” said Jillian Deines, lead author of the study and a postdoctoral scholar in Stanford’s Center on Food Security and the Environment (FSE) at the time of the research.

“Agriculture is a very tricky business to get right, and things typically don’t work out as planned” added senior author David Lobell, the Gloria and Richard Kushel Director of FSE and professor in Earth System Science. “Our view is that constant monitoring, evaluation, and learning is a key part of making agriculture truly sustainable.”

New experimental treatment can stop the growth of schwannoma tumors

Researchers showed that after just 21 days of the drugs being administered, tumor growth can be strongly and significantly reduced.
Photo Credit: MART PRODUCTION

Two novel and orally administered drugs can not only block the growth, but also shrink the size, of a tumor type found in the nervous system, new research has shown.

The tumors, schwannomas, most frequently grow on the nerves that bring hearing and balance information into the brain. Schwannomas are the most common nerve sheath tumor, and can occur in anyone but are also linked to a hereditary condition known as Neurofibromatosis Type II (NF2).

In NF2, where the function of the protein Merlin is lost in cells, patients frequently develop not only schwannomas, but also meningioma tumors associated with the brain and spinal cord.

The treatment of both tumor types is difficult, with surgery being the current mainstay but also carrying a high risk of damage to the surrounding normal nervous system tissue.

With an urgent need for new treatments, an international team of scientists focused on the Hippo signaling pathway, which normally controls organ size in human tissues and cells, but is dysregulated in multiple types of cancer.

An easier way to remove medical devices

MIT engineers have shown that medical devices made from aluminum can be disintegrated within the body by exposing them to gallium-indium, a liquid metal that seeps into the boundaries between the grains of the metal.
Credit: MIT based on figures courtesy of the researchers

By taking advantage of a phenomenon that leads to fractures in metal, MIT researchers have designed medical devices that could be used inside the body as stents, staples, or drug depots, then safely broken down on demand when they’re no longer needed.

The researchers showed that biomedical devices made from aluminum can be disintegrated by exposing them to a liquid metal known as eutectic gallium-indium (EGaIn). In practice, this might work by painting the liquid onto staples used to hold skin together, for example, or by administering EGaIn microparticles to patients.

Triggering the disintegration of such devices this way could eliminate the need for surgical or endoscopic procedures to remove them, the researchers say.

“It’s a really dramatic phenomenon that can be applied to several settings,” says Giovanni Traverso, the Karl van Tassel Career Development Assistant Professor of Mechanical Engineering at MIT and a gastroenterologist at Brigham and Women’s Hospital. “What this enables, potentially, is the ability to have systems that don’t require an intervention such as an endoscopy or surgical procedure for removal of devices.”

Traverso is the senior author of the study, which appears in Advanced Materials. Vivian Feig, an MIT postdoc, is the lead author of the paper.

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.