Boys and girls are equal in number at conception, but more female fetuses die during pregnancy, leading to a slightly higher number of males being born, researchers said Monday. The study in the Proceedings of the National Academy of Sciences is based on the largest dataset ever analyzed in the search to explain what is known as the human sex ratio, which has been poorly understood until now. Documentation came from the United States, and included "the sex ratios of fetuses at different gestational ages, including three-to-six-day-old embryos produced by assisted reproductive technologies, induced abortions, chorionic villus sampling, amniocentesis, and United States census records of fetal deaths and live births," said the PNAS report, authored by researchers at Harvard University and Oxford University. Scientists found that the human sex ratio is equal at conception, but that during gestation, there were certain times when male embryos were more likely to die than females, particularly in the first week after conception when there tended to be more abnormal male embryos than female embryos.
CAIRO (AP) — Egypt and Saudi Arabia are cooperating militarily to thwart a power grab in Yemen by Shiite rebels, but the agreement on how to deal with the region's complex and intertwined conflicts may stop there. The two countries' diverging interests were evident at the Arab summit over the weekend, particularly over the crises in Syria and Libya.
Police opened fire and one suspect died Monday after a car tried to ram its way into the headquarters of US National Security Agency, America's electronic eavesdropper. One police officer and a second suspect were hurt in the incident, the NSA's director for strategic communications Jonathan Freed said. It was not immediately clear whether the suspects were shot or wounded when their car crashed into a police security vehicle. Police opened fire but the car crashed into the security truck.