There is no shortage of theories but a dearth of experimental proof that any of them is correct. “The lack of experimental evidence is sometimes accompanied by passionate discussion,” said Dr. Adrian G. Guggisberg, the lead author. Hippocrates proposed in the fourth century B.C. that yawning got rid of “bad air,” and increased “good air” in the brain. The widely held modern view of this theory is that yawning helps increase blood oxygen levels and decrease carbon dioxide. If this were true, Dr. Guggisberg writes, then people would yawn more when they exercise. And people with lung or heart disease, who often suffer from a lack of oxygen, yawn no more than anyone else.
Disease kills off 40% of farmed catfish. This gene protects them.
Researchers watched for signs of withdrawal — but didn’t find any.
Compared to people who took a placebo, the brains of those who took caffeine pills had a temporarily smaller gray matter volume.
“It is more human to laugh at life than to lament it.”