All articles tagged with #narwhal
An international team used tensor tomography to map the narwhal tusk from nano to macro scales and found the outer dentine forms a left-handed helix while the inner mineralized collagen spirals in the opposite direction, creating a stable double-spiral structure that is genetically encoded and continues to grow, offering insights for materials design and clues about past environmental conditions.
Researchers using advanced 3D X-ray imaging from multiple synchrotrons revealed that the narwhal’s tusk is a double spiral: the outer cementum twists left, the inner dentin twists right, forming a biological counterbalance that enhances strength. The tusk, which is the narwhal’s left canine and can exceed two meters, grows through the jaw and lip and is commonly seen as a sexual signal, though its exact function remains debated. The findings, published in Nature, also suggest the growth pattern is genetically programmed and that the tusk could serve as a record of environmental change over the animal’s roughly 80-year lifespan, potentially inspiring new materials design.
A Nature Communications study using CT, diffraction, SAXS, tensor tomography and microscopy shows narwhal tusks contain two spirals—cementum left-handed and dentine right-handed—forming a double helix that gives exceptional stiffness and straight growth, and may record environmental changes across a whale's lifetime.
While several third-party Reddit iOS apps are shutting down due to API pricing, ad restrictions, and the removal of explicit content, Narwhal for Reddit will continue operating without ads. However, the developer plans to introduce subscriptions in the future to cover new costs. The subscriptions are expected to cost between $4 to $7 per month. Other apps like MultiTab for Reddit, Infinity for Reddit, and Relay for Reddit may also survive with paid subscriptions. Some apps, including RedReader, Dystopia, and Luna, will remain available after receiving accessibility exemptions. The shutdown of popular apps like Apollo and rif is fun for Reddit (RIF) will be a loss for longtime users.