|
|
In 1864, the first barbiturate (barbituric acid) was synthesized.
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
IgA antibodies protect body surfaces exposed to outside foreign substances. IgG antibodies are found in all body fluids. IgM antibodies are the first type of antibody made in response to an infection. IgE antibody levels are often high in people with allergies. IgD antibodies are found in tissues lining the abdomen and chest.
In most climates, 8 to 10 glasses of water per day is recommended for adults. The best indicator for adequate fluid intake is frequent, clear urination.
There can actually be a 25-hour time difference between certain locations in the world. The International Date Line passes between the islands of Samoa and American Samoa. It is not a straight line, but "zig-zags" around various island chains. Therefore, Samoa and nearby islands have one date, while American Samoa and nearby islands are one day behind. Daylight saving time is used in some islands, but not in others—further shifting the hours out of sync with natural time.
![Midway Island, an inhospitable atoll acquired in 1867, was valuable as a military base located midwa](https://biology-forums.com/gallery/47/medium_6_02_03_16_7_45_21_234011450.jpeg)
![This military command post is in South Korea, with both U.S. and South Korean personnel. South Korea ...](https://biology-forums.com/gallery/28/medium_482573_20_04_17_2_29_14_280501980.png)