After coming to America, they have a worse life than back home. What happened to the land of opportunity? http://news.yahoo.com/s/ap/20110326/ap_on_re_us/us_underemployed_immigrants#mwpphu-container NEW YORK â After finishing medical school in Bogota, Colombia, Maria Anjelica Montenegro did it all â obstetrics, pediatrics, emergency medicine, even surgery. By her estimate, she worked with thousands of patients. None of that prepared her for the jobs she's had since she moved to the United States: Sales clerk. Babysitter. Medical assistant. That last one definitely rubbed raw at times. "I know I was working in my field," the 34-year-old New York resident said. "But that is medical assistant. I'm a doctor." Montenegro is hardly unique, given the high U.S. unemployment rate these days. Her situation reflects a trend that some researchers call "brain waste" â a term applied to immigrants who were skilled professionals in their home countries, yet are stymied in their efforts to find work in the U.S. that makes full use of their education or training. Mohan Singh, 55, thought moving to the United States would be a smooth transition. Born and raised in India, he left his home country for Kuwait, where he worked in air conditioning and elevator maintenance. He lived in Kuwait for 25 years, started his own company and was successful enough to send his daughter and son to college in the United States. At their urging, Singh came to the U.S. in 2000. He said he thought "that I'll be getting the same job, I'll be getting into a good field, make a good life." It took seven years to complete the paperwork that allowed Singh to work here legally. When he applied for jobs, would-be employers focused on the fact that Singh had not worked in his field in the United States. "They cancel all my experience," he said. He now spends 12 hours a day, seven days a week, behind the wheel of a taxicab. It's a far cry from the work he's done for much of his life, Singh said, and the wages are much lower than those he once brought home. The whole experience has soured him on the idea of staying in America. He plans to move back to India in a couple of years, when his son is done with his post-graduate work. "I used to have money, I used to have good life," Singh said. "Over here, I'm hand to mouth."