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Brains run on constant streams of chatter. The roughly 85 billion nerve cells in the human brain converse by sending messages via molecules called neurotransmitters. These chemical conversations allow the brain to think, remember and feel, but the details of how those messages move remain mysterious.
To get a closer look, researchers led by...
Some 2.1 billion people, almost 30 percent of the world’s population, are overweight or obese.
Data from 1980 to 2013 show that the biggest increases in the prevalence of obesity in women occurred in Egypt, Saudi Arabia, Oman, Honduras and Bahrain, and for men, in New Zealand, Bahrain, Kuwait, Saudi Arabia and the United States.*/
Reviews & Previews
Dinosaurs Without Bones: Dinosaur Lives Revealed by their Trace FossilsAnthony J. MartinPegasus Books, $29.95
When people walk into a museum’s dinosaur hall, what makes them gasp in awe are the incredibly huge bones. An adult T. rex, which could be up to 12 meters long, had teeth the size of bananas. A humerus, or upper arm bone, of the largest (thankfully vegetarian) long-...
Reviews & Previews
Prisoners, Lovers, and Spies: The Story of Invisible Ink from Herodotus to al-Qaeda Kristie MacrakisYale Univ., $27.95
Pig’s bladder, gypsum, fig sap, alum and onion juice — there’s no eye of newt among invisible ink recipes, but blood of dormouse is fair game. By the end of science historian Macrakis’ nearly 3,000-year accounting of secret messages, she’s all but thrown in...
Letters to the Editor
Tracing ancient genes06/13/2014 - 15:30 Animals, Genetics, Anthropology
Prehistoric Europe was home to hunter-gatherers until migrating farmers muscled them out. Genetic information teased from ancient skeletons is helping scientists reconstruct this saga, as Tina Hesman Saey reported in “Written in bone” (SN: 5/17/14, p. 26).
Sometimes, untangling genetic history can be a little one-sided. Researchers often rely on mitochondrial DNA,...