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Reading brachycephalic dogs’ facial expressions requires extra cognitive processing by humans
People often look to dogs’ behavior, especially their facial expressions, for indications of their states of mind. Numerous studies show that this is a popular interpretation strategy. However, modern dog breeds vary greatly in size and structure, and few studies have explored how breed-specific morphology might affect humans’ ability to assess visual cues from the faces of different breeds of dogs.
Now, for the first time, a collaborative research team including scientists from Israel, Czechia, and Hungary has used eye-tracking to compare the visual attention patterns of humans observing photographs of normocephalic and brachycephalic dogs. A research paper detailing the team’s findings appears in Frontiers in Veterinary Science.
A More Accurate Prediction of Band-Gap Energies
Temperature is a tuning knob for semiconductor-band-gap energies, which in turn play a key role in the performance of optoelectronic devices. But computational tools for predicting this temperature dependence from first principles struggle to capture the influence of one main factor: many-electron effects in electron–phonon interactions. Xiaoxun Gong at the University of California, Berkeley, and colleagues now demonstrate a computational framework that properly accounts for these effects [1]. Their framework could aid the design of materials and devices with precisely tailored electronic and optical properties.
Theoretical calculations consistently underestimate the strength of electron–phonon interactions and how they modify band gaps at different temperatures. Previous studies indicated that this discrepancy likely stems from insufficient treatment of many-electron effects. To quantify the role of electron–phonon interactions more accurately, Gong and his colleagues have proposed a new framework that breaks down the total temperature-dependent modification of the band gap into various contributions. Within this framework, they analyzed electron–phonon interactions using a many-body perturbation theory, in which electrons’ energies and their perturbation by phonons are captured by the “GW” approximation.
To test their framework, the researchers computed the band gaps of diamond, silicon, and gallium phosphide at different temperatures. They found that the temperature-dependent band-gap modification was enhanced using the GW-based perturbation theory—especially compared to a description based on density-functional theory (DFT), the workhorse tool for first-principles electronic calculations. The new predictions for all three materials showed excellent agreement with previous measurements.
How dual-comb spectroscopy works and why it could reshape precision sensing
Spectroscopy has many applications, ranging from fundamental tests of quantum electrodynamics and investigations of molecular structure to environmental sensing, biomedical diagnostics and industrial monitoring. A highly promising spectroscopic instrument that has the potential to transform the field has emerged over the years: the dual-comb spectrometer, which relies on the interference of two mode-locked ultrafast lasers that produce broad frequency combs composed of evenly spaced narrow spectral lines.
A frequency comb is a spectrum of phase-coherent sharp laser lines that are evenly spaced. Such combs based on femtosecond mode-locked lasers, as pioneered at the Max-Planck Institute of Quantum Optics in the 1990s, have revolutionized measurements of frequency and time. In frequency metrology, a laser comb acts as a ruler in frequency space that conveniently links microwave and optical frequencies, and/or measures a large separation between two optical frequencies.
In the past two decades, frequency combs have found new applications. One of them is dual-comb spectroscopy. Dual-comb spectroscopy addresses the challenge of combining wide spectral coverage with high resolution and accuracy by using two optical frequency combs with slightly different repetition frequencies to map optical spectra directly into the radio-frequency domain. The method relies on time-domain interferometry and avoids mechanical scanning, enabling precise, rapid, and broadband measurements. Dual-comb spectroscopy has been implemented across the electromagnetic spectrum, from the terahertz to the visible range, with ongoing efforts towards the ultraviolet range.
Hidden brain circuit could explain how movement errors sharpen new skills
While humans are acquiring new skills that entail performing coordinated movements, such as walking, playing an instrument or skateboarding, their brains are known to continuously detect mistakes and correct movements over time. This gradual acquisition of task-specific movements is known as motor learning.
Past neuroscience studies suggest that a brain region known as the cerebellum plays a central role in motor learning. The cerebellum is a structure at the back of the brain that contributes to coordination, balancing the timing of voluntary actions and the execution of precise movements.
This brain structure hosts a type of nerve cell known as Purkinje cells (PCs), which receive input information via climbing fibers (CFs), nerve fibers that originate from a lower region in the brainstem. Neuroscientists have hypothesized that climbing fibers also carry signals that instruct the brain to adapt to movements based on earlier mistakes.
Mercury’s water ice may have been deposited by a larger, slower impactor than previously thought—in only one day
The source of the significant water ice deposits hidden in Mercury’s polar regions has been a topic of debate among researchers. A new study, published in the Journal of Geophysical Research: Planets, suggests that these deposits were accumulated in only one Mercurian day (176 Earth days) by a large impactor, such as a comet or asteroid. While previous studies have suggested a similar scenario, this is the first study to fully model the impact. Furthermore, these new models suggest that the impactor may have been larger and slower than previously suggested.
Being the closest planet to the sun, Mercury sees daytime temperatures of up to 430°C (806°F). On top of that, Mercury doesn’t have a true atmosphere. Instead, it has an ultra-thin, tenuous layer of gas, called an exosphere, in which gases are constantly blown into space and then replenished by the solar wind. While these aspects of Mercury should make water retention extremely difficult, both Earth-based and orbital observations have found reflective areas that indicate the presence of water ice hidden in permanently shadowed regions (PSRs) near Mercury’s north and south poles.
Scientists have suggested several potential sources of the ice found in PSRs. Some hypotheses include steady delivery by micrometeoroids, solar wind, or a single large, volatile-rich impact. Some studies have found that the ice appears to be relatively pure and “young” (at only a few 100 million years). These findings suggest a rapid, episodic delivery rather than slow accumulation, according to more recent studies.
Low-power, flexible radio-frequency transistors break 100 GHz barrier
Over the past decades, electronics engineers worldwide have been trying to develop devices that could enable even faster communications between devices, all while consuming less energy. To meet the demands of the sixth generation (6G) of wireless communication technology, these devices should operate at frequencies above 100 gigahertz (GHz).
So far, developing flexible electronic components that can operate at these high frequencies while consuming little power has proved challenging. One promising approach for fabricating these devices entails the use of carbon nanotubes (CNTs), extremely thin and cylindrical structures with advantageous electrical and thermal properties.
Researchers at Peking University and Stanford University recently developed new flexible and low-power CNT-based transistors that operate at frequencies above 100 GHz. These transistors, presented in a paper published in Nature Electronics, could potentially help to speed up communications between future smartphones, sensors, wearable devices, and other flexible devices.
Triply-eclipsing triple star system discovered with TESS
Using NASA’s Transiting Exoplanet Survey Satellite (TESS), astronomers have discovered a triply-eclipsing star system. The newfound system, designated TIC 295741342, consists of two sun-like stars in an eclipsing binary and a giant tertiary companion, which orbits the binary. The finding was reported in a paper published May 19 on the arXiv pre-print server.
Astrophysicists strike black gold with treasure trove of gravitational wave detections
Researchers from the University of Glasgow’s Institute for Gravitational Research are celebrating the publication of a vast new treasure trove of gravitational wave detections, hailed as a milestone marking the coming of age of gravitational astronomy.
The Gravitational Wave Transient Catalogue-5.0, or GWTC-5, is released online, with corresponding scientific papers submitted to Astrophysical Journal and Astrophysical Journal Letters.
This latest update details a total of 161 new signals from colliding black holes detected between April 2024 and the end of January 2025 by the gravitational wave detectors LIGO in the United States, Virgo in Italy, and KAGRA in Japan, known as the LVK collaboration. The publication brings the total number of gravitational wave signals detected to date to 390.