Top images (A): Illustrates the development of stem cells on hydrogel, a soft substrate, to pre-bone cells after the removal of water. Bottom images (B): Depicts the development of stem cells on glass, a hard substrate, to pre-fat cells after the addition of water.*
Adding or removing water from a stem cell can change the destiny of the cell, researchers have discovered in a new study published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).
Waves of vertebrae-building signals pulse outward in mouse cells mimicking a developing embryo.
Like a string of pearls, the spine is made of a series of similar vertebrae. A so-called segmentation clock creates this repetitive arrangement in developing embryos: Each time the clock ticks, a vertebra starts to form.
Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences have developed a simple device that mimics complex birdsongs. The device, developed by the group of L. Mahadevan, the Lola England de Valpine Professor of Applied Mathematics, of Organismic and Evolutionary Biology, and of Physics, uses air blown through a stretched rubber tube to recreate birdsongs found in nature, including the songs of zebra and Bengalese finches.