421 articles from THURSDAY 4.3.2021

Twistoptics: A new way to control optical nonlinearity

Engineering researchers report that they developed a new, efficient way to modulate and enhance an important type of nonlinear optical process: optical second harmonic generation -- where two input photons are combined in the material to produce one photon with twice the energy -- from hexagonal boron nitride through micromechanical rotation and multilayer stacking. Their work is the first to...

Why we're so bad at daydreaming, and how to fix it

We don't intuitively understand how to think enjoyable thoughts. But when researchers provided participants with a list of examples that were pleasant and meaningful, they enjoyed thinking 50% more than when they were instructed to think about whatever they wanted.

Twistoptics—A new way to control optical nonlinearity

Nonlinear optics, a study of how light interacts with matter, is critical to many photonic applications, from the green laser pointers we're all familiar with to intense broadband (white) light sources for quantum photonics that enable optical quantum computing, super-resolution imaging, optical sensing and ranging, and more. Through nonlinear optics, researchers are discovering new ways to use...

Apparent Atlantic warming cycle likely an artifact of climate forcing

Volcanic eruptions, not natural variability, were the cause of an apparent 'Atlantic Multidecadal Oscillation,' a purported cycle of warming thought to have occurred on a timescale of 40 to 60 years during the pre-industrial era, according to a team of climate scientists who looked at a large array of climate modeling experiments.

Less inflammation with a traditional Tanzanian diet than with a Western diet

Urban Tanzanians have a more activated immune system compared to their rural counterparts. The difference in diet appears to explain this difference: in the cities, people eat a more western style diet, while in rural areas a traditional diet is more common. A team of researchers believe that this increased activity of the immune system contributes to the rapid increase in non-communicable...

COVID-19 pandemic has increased loneliness and other social issues, especially for women

Social distancing guidelines have reduced the spread of COVID-19, but lockdowns and isolation also have created or aggravated other well-being concerns, reports new research. Mayo Clinic investigators found a significant increase in loneliness and a decrease in feelings of friendship during the pandemic. The study, published Feb. 20 in the journal Social Science & Medicine, also showed...

Apparent Atlantic warming cycle likely an artifact of climate forcing

Volcanic eruptions, not natural variability, were the cause of an apparent "Atlantic Multidecadal Oscillation," a purported cycle of warming thought to have occurred on a timescale of 40 to 60 years during the pre-industrial era, according to a team of climate scientists who looked at a large array of climate modeling experiments.

When peeking in your brain may help with mental illness

In recent years, researchers have begun using functional magnetic resonance imaging (fMRI) not just to better understand the neural bases of psychiatric illness, but also for experimental treatment of depression, ADHD, anxiety, PTSD, substance use disorder, and schizophrenia with real-time fMRI neurofeedback. But how well does it work?

Factoring in gravitomagnetism could do away with dark matter

Observations of galactic rotation curves give one of the strongest lines of evidence pointing towards the existence of dark matter, a non-baryonic form of matter that makes up an estimated 85% of the matter in the observable Universe. Current assessments of galactic rotation curves are based upon a framework of Newtonian accounts of gravity, a new article suggests that if this is substituted with...

This frog has lungs that act like noise-canceling headphones

To succeed in mating, many male frogs sit in one place and call to their potential mates. But how do females pinpoint a perfect mate among all the background noise of other frogs? Now, researchers have found that they do it thanks to a set of lungs that reduce their eardrum's sensitivity to environmental noise, making it easier to zero in on the calls of males.

Astrocytes derived from patients with bipolar disorder malfunction

Cells called astrocytes derived from the induced pluripotent stem cells of patients with bipolar disorder offer suboptimal support for neuronal activity. This malfunction can be traced to an inflammation-promoting molecule called interleukin-6 (IL-6), which is secreted by astrocytes. The results highlight the potential role of astrocyte-mediated inflammatory signaling in the psychiatric disease,...