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Surprising Control over Photoelectrons from a Topological Insulator

Berkeley Lab scientists discover how a photon beam can flip the spin polarization of electrons emitted from an exciting new material

Plain-looking but inherently strange crystalline materials called 3D topological insulators (TIs) are all the rage in materials science. Even at room temperature, a single chunk of TI is a good insulator in the bulk, yet behaves like a metal on its surface.

Researchers find TIs exciting partly because the electrons that flow swiftly across their surfaces are “spin polarized”: the electron’s spin is locked to its momentum, perpendicular to the direction of travel. These interesting electronic states promise many uses – some exotic, like observing never-before-seen fundamental particles, but many practical, including building more versatile and efficient high-tech gadgets, or, further into the future, platforms for quantum computing. (more…)

Sleep consolidates memories for competing tasks

Nature, Science

Sleep plays an important role in the brain’s ability to consolidate learning when two new potentially competing tasks are learned in the same day, research at the University of Chicago demonstrates.

Other studies have shown that sleep consolidates learning for a new task. The new study, which measured starlings’ ability to recognize new songs, shows that learning a second task can undermine the performance of a previously learned task. But this study is the first to show that a good night’s sleep helps the brain retain both new memories. (more…)

Sex at zero gravity

Health

University of Montreal researchers found that changes in gravity affect the reproductive process in plants. Gravity modulates traffic on the intracellular “highways” that ensure the growth and functionality of the male reproductive organ in plants, the pollen tube. “Just like during human reproduction, the sperm cells in plants are delivered to the egg by a cylindrical tool. Unlike the delivery tool in animals, the device used during plant sex consists of a single cell, and only two sperm cells are discharged during each delivery event,” explained Professor Anja Geitmann of the university’s Department of biology. “Our findings offer new insight into how life evolved on Earth and are significant with regards to human health, as a traffic jam on these highways that also exist in human cells can cause cancer and illnesses such as Alzheimer’s.” (more…)

Tooth pushes back modern monkeys’ first ancestor three million years

Nature, Science

The ancestor of all modern African monkeys was alive 3 million years earlier than previously thought and coexisted with members of a now-extinct branch of the monkey family tree, according to new evidence from anthropologists.

“We pushed back the origin of modern monkeys by a huge chunk of time,” said anthropologist Andrew Hill of Yale University, the senior researcher on the project. “This means there are all sorts of things we can think about. You can start to look at animal interactions that might have taken place.” (more…)

Researchers Solve Riddle of What Has Been Holding Two Unlikely Materials Together

Science

For years, researchers have developed thin films of bismuth telluride (Bi2Te3) – which converts heat into electricity or electricity to cooling – on top of gallium arsenide (GaAs) to create cooling devices for electronics. But while they knew it could be done, it was not clear how – because the atomic structures of those unlikely pair of materials do not appear to be compatible. Now researchers from North Carolina State University and RTI International have solved the mystery, opening the door to new research in the field.

“We’ve used state-of-the-art technology to solve a mystery that has been around for years,” says Dr. James LeBeau, an assistant professor of materials science and engineering at NC State and co-author of a paper on the research. “And now that we know what is going on, we can pursue research to fine-tune the interface of these materials to develop more efficient mechanisms for converting electricity to cooling or heat into electricity. Ultimately, this could have applications in a wide range of electronic devices.” (more…)

Tenfold boost in ability to pinpoint proteins in cancer cells

Health

Better diagnosis and treatment of cancer could hinge on the ability to better understand a single cell at its molecular level. New research offers a more comprehensive way of analyzing one cell’s unique behavior, using an array of colors to show patterns that could indicate why a cell will or won’t become cancerous.

A University of Washington team has developed a new method for color-coding cells that allows them to illuminate 100 biomarkers, a ten-time increase from the current research standard, to help analyze individual cells from cultures or tissue biopsies. The work is published this week (March 19) in Nature Communications. (more…)

Man who received nation’s first ‘breathing lung’ transplant at UCLA thankful for gift of life

Health

Grandfather, 57, looks forward to celebrating Easter with family and friends

Fernando Padilla could barely breathe or walk more than a few steps. An incurable disease, pulmonary fibrosis, was causing his lungs to turn to hardened scar tissue, and he was permanently tethered to an oxygen tank. His only hope was a double lung transplant.
(more…)

Protected areas successfully prevent deforestation in Amazon rainforest

Environment

ANN ARBOR — Strictly protected areas such as national parks and biological reserves have been more effective at reducing deforestation in the Amazon rainforest than protected zones that allow for controlled removal of trees and other natural resources.

In addition, protected areas established primarily to safeguard the rights and livelihoods of indigenous people performed especially well in places where deforestation pressures are high, two University of Michigan researchers and their colleagues determined. (more…)