Bart Sullivan, a senior vice president at WSP Cantor Seinuk, a firm that handles engineering for buildings like One World Trade Center, says building a residential skyscraper is generally more challenging than building a tall office building, partly because residential buildings have fewer internal columns and other core structural elements.

WSJ: Living The High Life

The core economies have deep structural problems and the world economy is in a state of disequilibrium, says Jan Dehn, an economist at Ashmore Group in the U.K. Ashmore has its hands in emerging market debt.

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Embedding the structural support in the core made it possible to cantilever the roof and thus wrap a glass facade around the building, using vast expanses of insulated, triple-pane glass and mahogany mullions.

WSJ: The Greening of a Midcentury Classic

Recruiting and developing a core of well-rounded IT professionals is laden with structural obstacles and unrealistic expectations.

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There is a structural change in the global economy, with slower growth in the core economies and troubled governments, and stronger growth in the emerging economies with stable governments.

FORBES: Economies Of Brazil & UK Show How Poor Get Rich Slowly