Dirty Water: Toxic Metallic Compounds
Along with oil and excess nutrients, toxic metallic compounds can also make their way to the marine environment and cause damage that may be passed along through the food web.
Dirty Water: Urban Runoff
The amount of oil that reaches the ocean from urban runoff and other terrestrial sources greatly exceeds the oil that comes from tanker spills.
Disappearing Species and the Endocrine System
Zoologist and World Wildlife Fund senior scientist Theo Colborn talks about the impact of environmental toxins on the endocrine systems of exposed animals. Dr. Colborn observes that some of the species being affected hav..
Disease and Ethnicity
Dr. Ed McCabe, Chief of the Mattel Children's Hospital at UCLA, talks about the link between certain genetic disorders and ethnicity. He focuses on Tay-Sachs disease, which shows up most commonly among Ashkenazi Jews and..
Dishonorable killings: punishing the innocent
The horrific practice of honor killing still prevails in many Middle Eastern and Central Asian countries - and, as this film demonstrates, it is wielded not only against rape victims but also to punish women for simple r..
Distributive Law Defined
Summary of the distributive law.
Distributive Law Demonstrated
The distributive law of multiplication over subtraction defined and explained.
Distributive Law at Work
A practical application of the distributive law is presented.
Divergent Paths: Cities of 17th Century Colonial America
Cities, even in the 17th century, play a prominent role in the economic and social life of the colonies. Early population centers--New York, Philadelphia, Boston and Charles Town--are often referred to as walking cities...
Divergent Paths: Contrast between Northern and Southern Colonies
The Southern and Northern colonies continue along divergent paths in the 17th and 18th centuries. Their physical environments are different, their populations diverse. But perhaps the factor that contributes most to thei..