|
|
Of the estimated 2 million heroin users in the United States, 600,000–800,000 are considered hardcore addicts. Heroin addiction is considered to be one of the hardest addictions to recover from.
Prostaglandins were first isolated from human semen in Sweden in the 1930s. They were so named because the researcher thought that they came from the prostate gland. In fact, prostaglandins exist and are synthesized in almost every cell of the body.
The ratio of hydrogen atoms to oxygen in water (H2O) is 2:1.
The U.S. Preventive Services Task Force recommends that all women age 65 years of age or older should be screened with bone densitometry.
Giardia is one of the most common intestinal parasites worldwide, and infects up to 20% of the world population, mostly in poorer countries with inadequate sanitation. Infections are most common in children, though chronic Giardia is more common in adults.
![C:N ratios differ a great deal among the tissues of pines and between the woody tissues of pines and](https://biology-forums.com/gallery/47/medium_33_09_09_11_10_11_48_17012005.jpeg)
![The crania, and especially the faces of KNM-ER 1813 and 1470, differ enough that some scientists inc](https://biology-forums.com/gallery/47/medium_275510_22_02_15_6_06_44_207742049.jpeg)