WASHINGTON, Oct. 7 (UPI) -- Democratic presidential candidate Barack Obama has widened his lead over Republican nominee John McCain during the past month, a CNN poll indicates.

The financial crisis and low approval ratings for President George Bush may have played a roll in the gains for Obama, D-Ill., in the latest CNN-Opinion Research Corp. poll.

The poll, released Monday, indicated 53 percent of likely voters said they back Obama for president, with 45 percent supported McCain. The 8-percentage-point lead doubles Obama's lead in the September CNN-Opinion Research poll.

Bush may be part of the reason why Obama improved in the polls, pollsters said. Only 24 percent said they approve of Bush's job as president, an all-time low for a CNN survey, pollsters said. The poll indicated 56 percent think the McCain's policies would be the same as those of Bush, up from 50 percent a month ago.

The financial crisis also appears to be contributing to Obama's lead in the poll. Sixty-eight percent expressed confidence in the Illinois senator's ability to handle the financial crisis, 18 points ahead of McCain.

The latest CNN-Opinion Research Corp. poll interviewed 1,006 people Friday-Sunday by telephone. The survey's margin of error is 3.5 percentage points.

Obama, McCain prep for second debate

NASHVILLE, Oct. 7 (UPI) -- The stepped-up rhetoric by both major-party U.S. presidential campaigns could offer a glimpse into Tuesday's debate in Nashville.

The second debate, taking place in Belmont University, is a town-hall format, with Democratic candidate Barack Obama and Republican nominee John McCain fielding questions not only from moderator Tom Brokaw of NBC News, but also from people in the audience and Internet participants who are uncommitted about their presidential choice.

Both camps sharpened their attacks in recent days. GOP vice presidential candidate Sarah Palin accused Obama of "palling around with terrorists who would target their own country." Obama's campaign released a campaign critical of McCain's involvement in the "Keating Five" savings-and-loan scandal in the 1980s.

At least 6 million questions were submitted online for consideration for Tuesday's debate, The New York Times (NYSE:NYT) reported, with Brokaw responsible for selecting about six or seven. Another 12 or so questions on foreign and domestic topics come from the audience of about 80 likely voters.

CNN's latest poll of polls indicates Obama has a 49 percent to-43 percent lead over McCain.

McCain spent time at his ranch near Sedona, Ariz, preparing for the debate. Obama prepped in Asheville, N.C.

Healthcare issues seek nominees' attention

NASHVILLE, Oct. 7 (UPI) -- Healthcare reform advocates say they're hoping the major-party U.S. presidential nominees will start talking more about insurance and cost issues.

As U.S. Sens. John McCain, R-Ariz., and Barack Obama, D-Ill., were preparing to meet Tuesday night in Nashville for their second presidential debate, the issues of U.S. residents without health insurance and reducing costs in the healthcare system have been pushed into the background because of the global credit crisis and energy prices, Politico, a Washington publication, reported.

A September poll by the Kaiser Family Foundation indicated the economy was considered the top issue by 56 percent of respondents, with the Iraq war second at 25 percent and healthcare third at 21 percent.

But those hoping to get healthcare back onto the front burner say the Nashville debate's town-hall-style format may allow for more questions on the subject, Politico said.

"There's some concern in some corridors that, given the current economic state of our budget and the economy overall, taking on healthcare may be just too much, too big. I would argue exactly the opposite," Ken Thorpe, executive director of the Partnership to Fight Chronic Disease, told Politco.

Mosul fight kills 3; Baghdad blast hurts 5

BAGHDAD, Oct. 7 (UPI) -- A U.S. soldier was among three people killed Tuesday during a skirmish with suspected al-Qaida in Iraq militants near Mosul in northern Iraq, officials said.

Also killed were an Iraqi police officer and an al-Qaida in Iraq member, CNN reported.

The battle began when U.S. soldiers and Iraqi police surrounded the home after a family reported a man wearing suicide vest had entered their house, the military said. U.S. forces called for an airstrike, which destroyed the home and killed the insurgent.

Also Tuesday, five people were injured in blasts near the Iraqi Foreign Ministry and a parking lot near the Green Zone in Baghdad, Iraqi police told KUNA, the Kuwaiti news agency.

U.S. military disputes Iran's jet report

TEHRAN, Oct. 7 (UPI) -- U.S. military officials disputed Iranian reports that a U.S. military jet was forced to land at an Iranian airport after violating the country's airspace.

Iranian media reported a Falcon jet was forced to land at an Iranian airport after entering the country's airspace from Turkey at a low altitude while en route to Afghanistan, CNN reported.

Two U.S. military officials in Washington told CNN that no military aircraft were forced down. However, the officials said the aircraft could have belonged to another government agency or possibly the Iraqi government.

The jet's crew and passengers were released to continue their flight to Afghanistan after questioning revealed they unintentionally strayed into Iranian airspace, the Iranian Fars News Agency reported.

U.S., Japanese physicists earn Nobel Prize

STOCKHOLM, Sweden, Oct. 7 (UPI) -- U.S. and Japanese scientists earned the 2008 Nobel Prize in Physics for their work on subatomic particle theory, Sweden's Nobel Foundation announced Tuesday.

Yoichiro Nambu of the Enrico Fermi Institute at University of Chicago was selected for "the discovery of the mechanism of spontaneous broken symmetry in subatomic physics," the Royal Swedish Academy of Sciences said in a news release issued by the Nobel Foundation.

Makoto Kobayashi, of the High Energy Accelerator Research Organization in Tsukuba, Japan, and Toshihide Maskawa, from the Yukawa Institute for Theoretical Physics at Kyoto University, were recognized for their discovery of "the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature," the foundation said.

Nambu's mathematical description of spontaneous broken symmetry in elementary particle physics and helped develop the Standard Model of particle physics, the foundation said. The model unified the smallest building blocks of matter and three of nature's four forces in one theory.

Kobayashi and Maskawa found a different set of broken symmetries, suggesting spontaneous occurrences existed in nature since the universe began. The pair explained broken symmetry within the Standard Model framework but required that the model extend to three families of quarks.

Nambu will receive half of the $1.4 million prize, with Kobayashi and Maskawa splitting the other half.