Roads and canals connected walled cities and villages. The communities were laid out around central plazas. Nearby, smaller settlements focused on agriculture and fish farming.
The government said Thursday that the salmonella outbreak that sickened at least 1,440 people appears to be over, but its ultimate source may never be known, partly because of shortcomings in the nation's food safety system.
Scientists for the first time have peered into people's brains to directly measure the ebb and flow of a substance notorious for its role in Alzheimer's disease.
TeenGrowth is a non-commercial Internet site that focuses exclusively on the educational health issues of adolescents.
Almost 12 percent of the deaths among American Indians and Alaska Natives are alcohol-related - more than three times the percentage in the general population, a new federal report says.
In an Aug. 26 story about a new TV ad linking hot dogs with cancer, The Associated Press, relying on figures provided by a nutrition adviser to the American Institute for Cancer Research, erroneously reported average risks for colon cancer and how eating hot dogs affects those risks. Karen Collins said she misstated the average adult's lifetime risk for getting colorectal cancer, which is about 5 percent, not 5.8 percent.
Talk about an extreme makeover: Scientists have transformed one type of cell into another in living mice, a big step toward the goal of growing replacement tissues to treat a variety of diseases.
More ominous signs Wednesday have scientists saying that a global warming "tipping point" in the Arctic seems to be happening before their eyes: Sea ice in the Arctic Ocean is at its second lowest level in about 30 years.
Purdue University on Wednesday reprimanded a scientist who has been accused of falsifying claims he produced nuclear fusion in tabletop experiments.
Tropical Storm Fay brought some good news to the state's parched Everglades and its liquid heart, Lake Okeechobee - lots and lots of water.
A Palestinian couple locked their disabled son and daughter away for decades out of fear they would ruin the marriage prospects of a healthy child if discovered, police said Wednesday.
New data show New York City residents are contracting the virus that causes AIDS at three times the national rate.
A judge on Wednesday granted temporary guardianship to the husband of a woman on a feeding tube in a case similar to the lengthy legal dispute over whether Terri Schiavo should be kept alive.
What does a company do when there's anecdotal evidence that two of its drugs are equally effective in treating a leading cause of blindness in the elderly, one costing patients $60 per treatment and the other $2,000?
Government regulators on Wednesday cleared the way for broader use of a blood test that can spare heart transplant patients the ordeal of repeated biopsies to check if their bodies are rejecting the new organ.
New satellite measurements show that crucial sea ice in the Arctic Ocean has plummeted to its second lowest level on record.
Science