How to Celebrate Pi Day. Pi is a mathematical constant that is the ratio of a circle's circumference to its diameter, and it is also one of the most revered mathematical constants in the known world. Pi Day was first officially celebrated on a large scale in 1988 at the San Francisco Exploratorium. Since then, Pi Day has been celebrated by millions of students and math-lovers. The holiday is celebrated on 14th March, since 3, 1, and 4 are the three most significant digits in the decimal form of pi. If you'd like to learn how to celebrate pi in due fashion, read on and it will be as easy as pi.
Acute vs Chronic. The difference between acute and chronic when used for diseases is that acute means extremely severe pain, brief and dangerous disease whereas chronic refers to a medical condition that lasts over a long period. Chronic also means something always present and recurring or something habitual.
Col. Philip Holcombe] So the difference between acute and chronic post-traumatic stress disorder is the timeline of the symptoms. So when the symptoms occur for less than four weeks but longer than two days, we diagnose that as acute PTSD. When the symptoms last for longer than four weeks, we call that chronic PTSD.