Researchers looked at 280 closely related pairs of plant species and 61 pairs of animals, determining how different their genomes are as well as searching for evidence of recent gene flow. They found that the likelihood of interbreeding drops off as soon as plants differ by about 0.3% across their genomes, while for the animals the decline didn’t start until about 1.8% divergence.

Why, then, did scientists think plants are so much more flexible about the similarity of their mating partner? In a related Perspective, Yaniv Brandvain points out that the study looked at genetic signatures of hybridization, not whether the species can successfully be crossed. So one possibility is that what works in a greenhouse just doesn’t happen in natural environments. “For example, plants cannot walk or fly and therefore may be more geographically isolated (less opportunity for gene flow) than are animals,” he writes.

Every solid exhibits some amount of electric response to being bent or deformed, called flexoelectricity. Most of these responses are far too weak to exploit—the world isn’t just a battery waiting to be tapped. But when researchers turned to ice, a prevalent solid on Earth and one of the most common solids in space, the story was different. Adding table salt (NaCl) created a solid where every ice particle was surrounded by a few nanometers of briny liquid. When the salty ice was bent and unbent, this fluid sloshed back and forth, creating a current of ions that conferred a flexoelectrical effect around 1000 times larger than that of pure ice and on par with specially designed materials.

Salty ice has plenty of advantages in the real world, such as being moldable (just think of fun-shaped ice trays), non-toxic, and requiring no trace elements, as found in typical electronics. The simple solid could be incorporated into engineering projects in polar areas where sunlight is too low for solar power and water threatens soft robotics’ wiring and batteries, though it’s not a great candidate for deep space applications since the key briny liquid freezes at -70ºC. In a related News & Views, materials scientist Daesu Lee writes that the work is important for “ reminding us that dramatic effects can sometimes be found in plain sight.”

The White Coat Waste Project, a self-described “taxpayer watchdog” that campaigns to eliminate animal research across the federal government, last week publicized a list of 17 grants categorized in NIH’s grants database as active and listed under the spending category “human fetal tissue.” The list encompasses a variety of projects, including studies focused on human brain development, childhood cancer, and treatments for HIV. Many involve using fetal tissue donated from elective abortions to develop humanized mice that model the human immune system, which can be used to study diseases and test drugs. But it’s not clear whether all of the studies actually involved the controversial material—or whether NIH’s pledge not to renew them signals the revival of restrictive policies on fetal tissue studies that President Donald Trump imposed during his first term in office to satisfy abortion opponents.

Still, the International Society for Stem Cell Research protested the move, citing the scientific and clinical importance of studies involving human fetal tissue. “We urge NIH to reject political pressure to discontinue research with [human fetal tissue] and instead reaffirm its role as a champion of evidence-based biomedical science,” society president Hideyuki Okano said in a statement.

The device, called DeepInMiniscope, aimed to be a less-invasive tool for imaging the brain. But first, it needed to solve basic issues with imaging biological systems, including light scattering, low contrast levels, and intricate subject matter. Rather than using a single camera lens with one big input, the researchers opted for more than 100 mini, high-resolution lenslets in their design. The data from each lens then fed into a neural network that reconstructed the complete picture in 3D.

Going forward, the researchers hope to make an even smaller device at two centimeters, a size they compare to a hat for a mouse. They also aim to speed up the image capturing speed, as well as iterate on the neural networks so the whole process goes more smoothly. Given its noninvasiveness, the authors hope the microscope can one day be used in real time on live patients to better assess the roots of their behavior.

“This technology not only advances our fundamental understanding of how the brain processes information and drives behavior, but also contributes to improving our understanding of brain disorders and the development of future therapeutic strategies in humans,” say the authors in a statement.

With contributions from Hannah Richter and Phie Jacobs

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