During the population bottleneck, after the great slaughter of American bison during the 1800s, the number of bison remaining alive in North America declined to as low as 541. During that period, a handful of ranchers gathered remnants of the existing herds to save the species from extinction.
Edema Overview. Edema (or Oedema) is the abnormal accumulation of fluid in certain tissues within the body. The accumulation of fluid may be under the skin-usually in dependent areas such as the legs (peripheral edema, or ankle edema), or it may accumulate in the lungs (pulmonary edema).dema Overview. Edema (or Oedema) is the abnormal accumulation of fluid in certain tissues within the body. The accumulation of fluid may be under the skin-usually in dependent areas such as the legs (peripheral edema, or ankle edema), or it may accumulate in the lungs (pulmonary edema).
Barium enema series facts. 1  A barium enema (lower GI series) is an X-ray procedure used to define the anatomy of the large intestine (colon) and the rectum. 2  A barium enema involves filling the colon and rectum with a white liquid material (barium) often followed by air (double-contrast barium enema).arium enema series facts. 1  A barium enema (lower GI series) is an X-ray procedure used to define the anatomy of the large intestine (colon) and the rectum. 2  A barium enema involves filling the colon and rectum with a white liquid material (barium) often followed by air (double-contrast barium enema).