Since then America has introduced sanctions that target Iran's central bank, the country's main conduit for oil transactions, by penalising any foreign financial institutions doing business with it.

ECONOMIST: Tougher sanctions: From half-hearted to harsh | The

And on key international issues such as UN sanctions on Iran, a "strategic partnership" with Europe, Georgia's future as an independent conduit for central Asian oil and gas, and a final settlement in Kosovo and the Balkans, European diplomats say Russia's positive cooperation is essential.

CNN: Highlights from the world's press

The EU also agreed to freeze the assets of Iran's central bank, the conduit for the country's oil revenue, and ban trade with its petrochemical industry.

WSJ: Iran Blasts West Over Oil Embargo

The conduit will ensure a flow of Siberian oil to fuel China's burgeoning economy--which Beijing estimates will expand by 8% this year.

FORBES: Magazine Article

Mash an avocado with a pinch of salt and a drizzle of oil, and you'll find it an ideal condiment and flavor conduit for nearly any meal.

NPR: What's in a Name? The Avocado Story