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It's no secret that a roll in the hay, and all that leads up to it, feels good. Endorphins are the neurotransmitters in your brain that reduce pain and, in the absence of pain, can induce euphoria. A rush of such chemicals might seem like a temporary solution to a dreary day, but there are added benefits, not the least of which is expressing affection and strengthening the bonds of a relationship. Oxytocin is released by the pituitary gland upon orgasm; often referred to as the "hormone of love" or the "cuddle chemical," it is associated with feelings of bonding and trust, and can even reduce stress.

By the grizzly standards of war-torn Iraq, fighting yesterday in the mountains in the northern part of the country was a mild affair. Iranian artillery shelled villages in the Qandil mountains that are home to various Kurdish militant groups, one of which — the Party for a Free Life in Kurdistan (PEJAK) — is waging a guerilla insurgency against the Iranian government. Though hundreds of villagers fled their homes and two women were wounded, such cross-border violence is becoming a regular feature of life in the north. But yesterday's attack could also be a prelude to a larger struggle.

Whether or not the Iranians attack, the timing of build-up is ominous. Last week, the United States announced that it may list Iran's Revolutionary Guard — a branch of the country's military — as a terrorist organization for supplying explosives to Shi'ite militias in Iraq for use against American soldiers. The statement was part of a growing White House campaign aimed at either intimidating the Iranian regime, or at building a case for an American strike against Iran. In that light, yesterday's shelling is a reminder that Iran has the ability to confront the U.S. not just on the streets of Baghdad but also in the one part Iraq so safe that there are hardly any American soldiers: Iraqi Kurdistan.

But the Iraq's Kurdish region — the country's only success story — is looking increasingly beleaguered. Besides the Iranian army, the Turkish army is also massed at their border with northern Iraq, threatening an invasion if Iraq's Kurds don't do something about another Kurdish radical group, the PKK, which is fighting its own insurgency against the Turkish state. The ruling Kurdish parties of northern Iraq say there is little they can do about these radical groups. Not only are the PKK and PEJAK hardened guerilla fighters in formidable terrain, but the Iraqi Kurds' own security forces are stretched pretty thin keeping their territory safe from Arab terrorists in the rest of the country. That threat is as real as ever. The official death toll from last week's suicide attacks against several towns near Iraqi Kurdistan has risen to over 400 and continues to climb.

Iraq's Kurdish leaders have long been trying to steer a course between their patrons in Washington and with their powerful neighbors in Tehran. Though they have America to thank for freeing them from the genocidal grip of Saddam's regime, many Iraqi Kurdish political parties took refuge in Iran during those grim years. This spring, Kurds protested vigorously when American soldiers captured several Iranian agents posing as diplomats in the Kurdish regional capital of Arbil. An Iranian incursion into Iraqi Kurdistan would be a poor way of saying thanks.

But these days Iraq's Kurds aren't feeling the love from anyone. Last week, America's ambassador to Iraq Ryan Crocker said he didn't think that it would be possible to hold a referendum on the status of Kirkuk this year. Iraqi Kurds consider the oil-rich city of Kirkuk — which is currently under control of the central government of Baghdad — to be the "Jerusalem" of Kurdistan, stolen from them by a Baathist ethnic-cleansing campaign in the 1980s. The Kurds have made the return of Kirkuk a central pre-condition to their participation in a federal Iraq, and will regard any delay as a betrayal. But then again, they are used to betrayal. As the saying goes, the Kurds — a small ethnic group living in the shadows of great empires — have never had any true friends but the mountains.

“This is the first study to pinpoint a robust sex difference in the red-green axis of human color vision,” says Yazhu Ling, co-author of the study. “And this preference has an evolutionary advantage behind it.”

Ling speculates that the color preference and women's ability to better discriminate red from green could have evolved due to sex-specific divisions of labor: while men hunted, women gatherered, and they had to be able to spot ripe berries and fruits. Another theory suggests that women, as caregivers who need to be particularly sensitive to, say, a child flushed with fever, have developed a sensitivity to reddish changes in skin color, a skill that enhances their abilities as the “emphathizer.”

Ling says that she and her colleagues plan to expand their research in future studies to other cultures — not only British and Chinese — and age groups, including infants, to further test the nature-versus-nurture concept.

Access to the main flooded mine was blocked, and there was no indication whether the miners were still alive or how long it would take to pump out the water. About 60 angry relatives crowded the gates of a company compound, complaining no information had been released?not even a list of the names of the trapped miners.

Though the first documented medical abortion in the U.S. dates back to 1950, it wasn't until 2000 that the Food and Drug Administration approved the contentious medical-abortion drug, mifepristone (still commonly referred to by its clinical-trial designation, RU-486), as an alternative to the conventional surgical procedure. Since then, more than 500,000 U.S. women — and millions more worldwide — have used mifepristone to terminate pregnancy. Now a new study appearing in the August 16 issue of the New England Journal of Medicine reports that the drug, at least in the long term, is safe.

Though the rate of abortion has generally been dropping since the mid-1990s, U.S. doctors still perform nearly 1.3 million abortions a year, and the percentage of those using mifepristone continues to increase. According to a recent report from the Guttmacher Institute, "at one large network of providers, the proportion of early abortions performed with mifepristone increased from 9% of eligible women in 2001 to 24% in 2004."

Relying on abortion and pregnancy data on more than 11,600 women from the Danish National Patient Registry, Zhang and colleagues at the University of California, Los Angeles, and Aarhus University in Denmark, analyzed the impact of an early first-trimester abortion — using drugs versus surgery — on women's long-term reproductive health. After adjusting for variables such as maternal age, number of births prior to abortion and gestational age at the time of abortion, researchers found no increase in risk of ectopic pregnancy, miscarriage, premature birth or low birth weight in the medication group, as compared with the women who got surgical abortions. In both groups, ectopic pregnancies occurred about 2.4% of the time; miscarriages occurred about 12.5% of the time.

Why the disparity between the new results and the earlier study? Zhang points to the small sample size and self-reported data in the earlier study, compared with Zhang's large cohort and national-registry information. What's more, the focus of the previous study was not abortion per se, but general risk factors for ectopic pregnancy, including women's history of smoking and pelvic infectious disease. "In some ways, they found this association accidentally," says Zhang, "and the author did not provide any explanation. We weren't sure whether that finding was just by chance or whether it was real."

The current data show that women who use mifepristone are no better or worse off than those who choose surgical abortion, but the study didn't measure either group against women who have never had an abortion. Most existing research shows that surgical abortions have no effect on overall health risks, but the research findings on medical abortions are slim. One other paper, a Chinese study published in 2004, also in the American Journal of Epidemiology compared three groups of women — those who had no abortion, one surgical abortion or one medical abortion — and found no difference among them in risk of low birth weight or premature birth.

Apart from the long-term health effects of RU-486, some doctors still question the drug's safety in the short-term. Between 2003 and 2006, seven women — six in the U.S. and one in Canada — died after using mifepristone together with misoprostol, or misoprostol alone. The two drugs are routinely prescribed in combination; the first terminates the pregnancy, while the second causes uterine contractions and expels it. Most of the women died from infection with a dangerous, rare bacterium called Clostridium sordellii, one of the Clostridium species that may normally live in the vagina of healthy, non-pregnant women. Most also took misoprostol vaginally — many doctors prescribe it that way, though the drug is federally approved to be taken by mouth. But there is no evidence to date that the abortion drugs or how they were administered increased the women's vulnerability to the bug.

The death toll was the highest in a concerted attack since Nov. 23, when 215 people were killed by mortar fire and five car bombs in Baghdad's Shiite enclave of Sadr City.

The bombs tore through the districts near Qahataniya, 75 miles west of Mosul, Iraq's third-largest city, said Abdul-Rahman al-Shimiri, the top government official in the area, and Iraq army Capt. Mohammed Ahmed.

Yazidis are members of an ancient, primarily Kurdish, religious sect that worships an angel figure some that Christians and Muslims believe to be the devil.

Al-Shimiri and Ahmed said at least 30 homes were destroyed in the bombings.

Dhakil Qassim, mayor of Sinjar, a town near where the attacks occurred, said al-Qaida in Iraq was behind the bombings, citing what he said were Kurdish government intelligence reports. "This is a terrorist act and the people targeted are poor Yazidis who have nothing to do with the armed conflict," Qassim said. "Al-Qaida fighters are very active in this area near the Syrian border."

U.S. helicopters swooped into the area to evacuate the wound to hospitals in Dahuk, a Kurdish city near the Turkish border about 60 miles north of Qahataniya.

Civilians cars and ambulances also rushed the wounded to hospitals in Dahuk, police said.

(GHAZNI, Afghanistan) — Two women among the 23 South Koreans kidnapped by the Taliban in mid-July were freed Monday on a rural Afghan roadside and then driven to a U.S. base, the first significant breakthrough in a hostage drama now more than three weeks old.

Wearing scarves on their heads, khaki trousers and traditional Afghan knee-length shirts, the women were driven to the U.S. base in Ghazni city, where American soldiers searched them and then let them enter. Both carried bags.

They were brought to the arranged meeting point on the side of a road in rural Ghazni province by an Afghan named Haji Zahir, who also got into the Red Cross vehicle with the freed hostages.

The Taliban decided to release these two "for the sake of good relations between the Korean people and the Taliban," said Qari Yousef Ahmadi, who claims to speak for the insurgent group.

"We are expecting the Korean people and government to force the Kabul administration and the U.S. to take a step toward releasing Taliban prisoners," Ahmadi said by telephone from an undisclosed location.

Ghazni Gov. Marajudin Pathan ruled out a Taliban prisoner swap.

"Our position is the same, we are not releasing (any Taliban prisoners)," Pathan told reporters.

The South Korean Foreign Ministry identified the freed hostages as Kim Kyung-ja and Kim Ji-na. Previous media reports said they were 37 and 32 years old, respectively.

Two male captives were executed by gunfire in late July. Fourteen women and five men are still being held.

The Taliban have been demanding the release of 21 militant prisoners being held in jails by the Afghan government and U.S. military at the base at Bagram. The government has said it won't release any prisoners out of fear that kidnapping could become an industry in Afghanistan.

The South Korean government confirmed the release of the two hostages, and said they were under protection in a safe location. Seoul called for the other captives to also be freed.

"We urge the kidnappers to release our people and we will make efforts for the safety and release of South Koreans," said Foreign Ministry spokesman Cho Hee-yong.

The women, who the Taliban have said are ill, were among a church group volunteers kidnapped by militants on July 19.

The local governor has suggested in the past that the hostage standoff could be solved with a ransom payment.

The release comes after face-to-face talks Friday and Saturday in Ghazni between two Taliban leaders and four South Korean officials.

Ahmadi said that while talks continue, the remaining hostages will be safe.

"During these negotiations, there will no threats to the other Korean hostages. We are waiting for the result of these negotiations. After the negotiations, the Taliban leadership will make a decision about these 19 Korean hostages," he said.

Separately, a suicide bomber targeted a U.S.-led coalition convoy in eastern Afghanistan.

The blast in Khost province killed the bomber, said Gen. Mohammad Ayub, the provincial police chief. There were no immediate reports of casualties among the U.S. forces.

A spokesman for the U.S.-led coalition said they were aware of a car bomb in the east but had no further details.

In the south, Afghan police and army soldiers thwarted a planned militant ambush at the district chief's compound, and the ensuing clash left nine militants dead, said provincial police chief Sayed Agha Saqib.

During a cleanup operation after the battle, a roadside bomb hit a police vehicle in the same district, killing five officers and wounding two, Saqib said.

Violence in Afghanistan has risen sharply during the last two months. More than 3,700 people, mostly militants, have been killed in insurgency-related violence this year, according to an Associated Press tally of casualty figures provided by Western and Afghan officials.