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Author Question: In discussions of barriers to entry, what is meant by the term "virtuous cycle"? (Read 432 times) |
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.
When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).
Oliver Wendell Holmes is credited with introducing the words "anesthesia" and "anesthetic" into the English language in 1846.
Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.