Month: March 2006

Scurrying Salamanders

TL:DR – Short news article from 2006 about salamanders. The headline alludes to a lyric from a song by the band Genesis, The Carpet Crawlers.

Salamanders can transform from an aquatic juvenile form into their terrestrial, adult form only if the stream bed on which they develop is of the right nature. A study published today in the journal BMC Biology reveals that the Oklahoma salamander Eurycea tynerensis metamorphoses into a terrestrial adult form in streambeds composed of fine, tightly packed gravel but stays in the juvenile form in loosely packed streambeds composed of large particles.

The study by Ronald Bonett and Paul Chippindale from the University of Texas at Arlington, Texas, USA, exemplifies how small habitat differences can influence developmental patterns and morphology, they also suggest that such microstructure changes could influence a species’ evolution too.

Bonett and Chippindale explain that large gravel creates porous streambeds with large spaces between particles, where aquatic paedomorphic salamanders can access sub-surface water during dry months. However, if these spaces are filled in by small particles, metamorphosis is the only way they can survive when surface streams dry-up.

The Inner Secrets of Rocks and Fossils

Researchers at UCLA have produced the first 3D images of fossils embedded in rocks aged between 650 and 850 million years old. New microscopy and spectroscopy techniques allowed them to sneak an interior peek inside ancient rocks without having to crack them open. The research allows them to spot signs of ancient microscopic life, such as fossil cell walls and could be useful in studying extraterrestrial rocks in the search for alien life.

Dig inside the full story in David Bradley’s news page on spectroscopynow.com

Electronic Speed-trap

A speed-trap for electrons joyriding through single crystals based on MRI can reveal their velocities and produce an image showing an electron density map of the electrons in the crystal. In a kind of cold-case re-opened, the technique provides new evidence to show that the electrons are not breaking Ohm’s law.

Noam Kaplan of the Hebrew University in Jerusalem and colleagues M Drescher and E Dormann at Karlsruhe University, Germany, have developed a technique to measure electron velocity, separate from the electric current flowing through the material. Current is analogous to measuring the number of cars that pass a speed trap rather than the velocity of individual vehicles. The team used MRI, not to produce an image, but to detect electrons simply by monitoring their spin. To measure electron velocity, however, they scanned the crystal, a radical cation salt, with no current flowing.

You can find out what their experiments revealed in David Bradley’s latest news round-up on spectroscopynow.com