Pak needs to do more in fight against terrorism: CIA Chief

WASHINGTON: Cooperating with Pakistan in the fight against terrorism is essential to maintain pressure on Al-Qaeda after Osama bin Laden's death, CIA chief Leon Panetta said ahead of a US Senate hearing Thursday.

"Continuing cooperation with Pakistan is critical to keep a tremendous amount of pressure on Al-Qaeda's leadership and the networks that provide it support and safe haven at a time when it is most vulnerable," Panetta said in written responses to US lawmakers.

But he warned that Pakistan, which is a large recipient of US aid, needed to do more to step up in the fight against terrorism. "Future requests for security assistance will be informed by Pakistan's response to the counter-terrorism steps we have proposed," he said.

Panetta is to attend Thursday's hearing of the Senate Armed Services committee as it considers his nomination to be the next secretary of defense to replace Robert Gates.

The current CIA chief acknowledged in his responses that "the relationship with Pakistan is not always easy and we have our differences." But he said: "One of the key lessons from this operation is that we have seen no clear evidence to indicate that senior Pakistani leaders were involved in harboring Osama bin Laden or knew of his whereabouts."

The Al-Qaeda leader and mastermind of the September 11, 2001 attacks was killed by a US commando raid on his Pakistani hideout on May 2, after a decade-long manhunt to find him.

"If confirmed, I will continue to work with our partners in both Afghanistan and Pakistan to achieve our goal of eliminating terrorist networks that threaten the United States and our allies and partners," Panetta wrote.

Pakistan has lost some 11,000 soldiers in its counter-terrorism operations in the northwestern tribal areas and has suffered "more than 30,000 civilian casualties in recent years, most recently in significant attacks following the bin Laden operation," he said. But he stressed: "It is vital that Pakistan live up to its end of the bargain, cooperating more fully in counterterrorism matters and ceasing to provide sanctuary to Afghan Taliban and other insurgent groups."

Why smokers gain weight when they quit

WASHINGTON: Scientists say they've finally discovered why smokers tend to gain some weight when they kick the habit.

It turns out that nicotine can rev up brain cells that normally signal people to stop eating when they're full, researchers report in Friday's edition of the journal Science.

The weight connection isn't huge: On average, quitters gain less than 10 pounds. Still, it's a worry that many smokers cite when asked why they don't try to quit. Now the question is whether the discovery might lead to better treatments to help them quit without worrying about weight.

Yale University associate research scientist Yann Mineur stumbled onto the connection while studying a nicotine-related substance in mice - and the animals suddenly started eating less.

Nicotine hooks onto a variety of receptors, or docking sites, on the surface of cells. That's how it triggers addiction in one part of the brain.

But when it comes to weight, the Yale research found that both nicotine and the related drug cytisine were activating a different receptor than the one involved in addiction. This one is located on a small set of neurons in the hypothalamus, a region that regulates appetite.

When they gave nicotine to mice without that cellular pathway, it didn't help them lose weight like it did normal mice.

Smoking causes cancer, heart attacks and a host of other ailments so worry about modest weight gain shouldn't deter someone from quitting. But smokers who do have that concern should try nicotine-based smoking-cessation treatments, said study senior author Marina Picciotto, a Yale professor of psychiatry and neurobiology.

The other drug used in the mouse experiments, cytisine, is sold in Eastern Europe for smoking cessation but not in the U.S., and she'd like to see if there's data on the weight of smokers abroad who've used it.