London, October 16 : American researchers have developed the first tunable “noiseless” amplifier, which can boost the speed and precision of quantum computing and communications systems.

Scientists at the National Institute of Standards and Technology (NIST) and JILA, a joint institute of NIST and the University of Colorado (CU) at Boulder, say that the amplifier works by significantly reducing the uncertainty in delicate measurements of microwave signals.

Conventional amplifiers add unwanted “noise”, or random fluctuations, when they measure and boost electromagnetic signals.

Though amplifiers that theoretically add no noise have been demonstrated before, the new technology offers better performance.

Washington - The new "working poor" in the United States have all the things expected of average Americans: a house, a car and a television. Though they work to the point of exhaustion, they cannot make ends meet. Their refrigerators are empty, their bank accounts overdrawn.

"If you keep your nose to the grind, you can get ahead in this country," so goes the motto.

For nearly 25 per cent of the US middle class, this no longer applies. Victims of the economic crisis, they have turned the traditional concept of poverty on its head.

Take Vicky Gardner, a 44-year-old geriatric nurse. Every morning she drops her two children off at school on the outskirts of Washington, D. C.

Washington - In the final television debate of the 20-month US presidential campaign, Republican John McCain and Democrat Barack Obama Wednesday had sometimes testy exchanges over taxes and the increasingly negative tone of the final weeks before the election.

With 20 days before the November 4 general elections, the two candidates held an often fast-paced, free-wheeling debate on domestic policy at Hofstra University in New York state.

Washington - US Vice President Dick Cheney underwent treatment Wednesday after doctors discovered an abnormal rhythm in his heart, the White House said.

Cheney cancelled plans to attend a campaign event in Illinois and went to George Washington University Hospital in the capital for the outpatient procedure, involving an electrical impulse to restore a normal rhythm in his heart's upper chamber, Cheney spokeswoman Megan Mitchell said.

Cheney, 67, has a history of heart problems and suffered four heart attacks beginning in his 30s. The most recent attack occurred in 2000.

San Francisco - Online retailer and auction house eBay posted a 5-per-cent increase in third-quarter earnings Wednesday but said that the stalling economy would leave its annual revenue well below expectations.

Following the announcement, the company's shares fell 12 per cent in extended trading.

The pioneering website reported net income of 492.2 million dollars, or 38 cents a share, compared with a loss of 935.6 million dollars, or 69 cents a share, in the same quarter a year ago, when the company took a large charge in connection with its acquisition of Skype, the online phone and text-messaging service.

New York - US stocks continued dropping through Wednesday, hit by the largest drop of retail sales in three years, growing worry over a US recession and a record federal budget deficit.

The three major US indices shed more than 5 per cent each by 1845 GMT, with the negative momentum dragging down Europe's markets, where Europe's blue-chip Stoxx50 closed 5 per cent down.

US Federal Reserve chief Ben Bernanke warned that the emergency action taken by the Bush administration in response to the financial crisis is unlikely to produce a swift economic recovery.