Protecting Cows—and People—from a Deadly Disease
Making the most of a meal
Cleaning Up Fish Farms
Tree Frogs
The Secret Lives of Grizzlies
A Wild Ferret Rise
Roboroach and Company
World’s largest lizard is venomous too
Puberty gone wild
The Science Fair Circuit
Flightless Birds
Chemistry and Materials
A Diamond Polish for Ancient Tools
Moon Crash, Splash
Flytrap Machine
The Shape of the Internet
Small but WISE
Games with a Purpose
Dinosaurs and Fossils
Meet your mysterious relative
Dino Babies
An Ancient Feathered Biplane
E Learning Jamaica
2014 GSAT Results for Jamaican Kids
Results of GSAT are in schools this week
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Salty, Old and, Perhaps, a Sign of Early Life
Island of Hope
Life trapped under a glacier
Hazy with a Chance of Sunshine
Spotty Survival
Plant Gas
Finding the Past
Little People Cause Big Surprise
A Human Migration Fueled by Dung?
Childhood's Long History
Electric Catfish
Manta Rays
Food and Nutrition
Symbols from the Stone Age
Food for Life
Moving Good Fats from Fish to Mice
GSAT English Rules
Problems with Prepositions
Who vs. Whom
GSAT Exam Preparation Jamaica
GSAT stars reap scholarship glory
GSAT Exam Preparation
Preparing for the GSAT Exam
GSAT Exams Jamaica Scholarships
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
GSAT Scholarship
GSAT Mathematics
A Sweet Advance in Candy Packing
Setting a Prime Number Record
Play for Science
Human Body
What the appendix is good for
Heavy Sleep
The tell-tale bacteria
African Wild Dog
Raise a Lifelong Reader by Reading Aloud
Children and Media
How children learn
The Particle Zoo
The Pressure of Scuba Diving
Powering Ball Lightning
A Change in Leaf Color
A Giant Flower's New Family
Underwater Jungles
Space and Astronomy
Ringing Saturn
Catching a Comet's Tail
Pluto, plutoid: What's in a name?
Technology and Engineering
Are Propellers Fin-ished?
Squeezing Oil from Old Wells
Drawing Energy out of Wastewater
The Parts of Speech
What is a Noun
Adjectives and Adverbs
Seen on the Science Fair Scene
Troubles with Hubble
Revving Up Green Machines
Warmest Year on Record
Recipe for a Hurricane
The solar system's biggest junkyard
Add your Article

Return of the Lost Limbs

When people lose legs after accidents or illnesses, emergency care and artificial limbs often allow them to walk again. But salamanders and newts in the same situation don't need doctors or artificial body parts. They can grow limbs back on their own. Scientists have known for a long time that certain animals can regenerate limbs, but they haven't quite figured out how these creatures do it. Researchers from University College London have now come up with some new insights. Their work may lead to breakthroughs that could eventually enable people, too, to regrow lost limbs. The researchers started with two simple observations: When you cut off a newt's leg at the ankle, only the foot grows back. If you cut off a leg at the base, the whole leg grows back. In both cases, the regrowth begins with stem cells . Stem cells are unspecialized cells that can develop into nearly any type of cell in the body. But how do a newt's stem cells know when to regrow only a foot and when to regrow an entire leg? This question relates to another mystery: In newts, a severed leg will grow back only if the bundle of nerves in it also grows back. But if something prevents the nerve bundle from growing, the stem cells at the site of the wound won't multiply to produce a new leg. In its study, the British team zeroed in on a protein called nAG. When the team prevented nerves in a limb from growing, but added the nAG protein to stem cells in the limb, the limb still regrew. The scientists suspect that nerves in the stub of a limb signal the release of the nAG protein. That protein seems to guide limb regrowth. People and other mammals have proteins that are similar to nAG. Further research into these compounds may some day help human limbs and organs heal themselves.—Emily Sohn

Return of the Lost Limbs
Return of the Lost Limbs

Designed and Powered by™