1 Down syndrome, usually is caused by an extra copy of chromosome 21 (trisomy 21). Characteristics include decreased muscle tone, asymmetrical skull, slanting eyes and mild to moderate mental retardation.  Edward's syndrome, which is the second most common trisomy after Down syndrome. It is a trisomy of chromosome 18.
Guanxi describes the basic dynamic in personalized networks of influence, and is a central idea in Chinese society.
The Bixi system is a public bike share system. Rated the best in the world, it was designed and developed in Montreal and has since been exported to many cities around the world including New York City, London, UK, and Melbourne, Australia.