Androstenone is a derivative of testosterone that is a potent ingredient in male body odor. To some it smells like stale urine, others find it sweet and pleasant. Some can't smell it at all.

Androstenone is used by some mammals to convey social and sexual information so if you know a girl who doesn't like the way you smell, it may be genetic variations in a single odorant receptor called OR7D4 - don't take it personally, it's in her genes.

Because Gary Taubes is probably the country’s best health journalist, his article in today’s NY Times Magazine (”Do We Really Know What Makes Us Healthy?”) about the perils of epidemiology especially interested me. It’s the best article on the subject I’ve read. He does a good job explaining what’s called the healthy-user bias — people who take Medicine X tend to make other healthy choices as well. Does wine reduce heart attacks? Well, probably — but people who drink more wine also eat more fruits and vegetables.

If you've ever watched birds at a feeder, you've seen changes in how many birds feed from season to seasons and year to year. Do some of the long-term shifts reflect changes in the environment and climate? To find out, the Cornell Lab of Ornithology's Project FeederWatch is asking bird watchers for help.

FeederWatchers count the birds at their feeders each week and send the information to the lab. They've helped document unusual bird sightings, winter movements and shifting ranges of some bird species over the past 20 years.

A groundbreaking environmental study to be published in a prestigious American science journal proves that mercury atmospheric emissions will end up in fish in as little as three years. Biologists from the University of Alberta in Edmonton, Canada, played a key role in designing and carrying out the experiment.

The study concludes that if mercury emissions from coal-fired power plants and other industrial activities were to be cut immediately, the amount showing up in fish would begin to go down within a decade.

This breakthrough study (called METAALICUS – Mercury Experiment to Assess Atmospheric Loading in Canada and the United States) involved government agencies and universities on both sides of the border. It has global implications.

French surgeons successfully removed a woman’s gall bladder through her vagina, according to a report in the September issue of Archives of Surgery.

The history of surgery has moved toward less invasive procedures, according to background information in the article. “Whenever it was possible, patients would ask for a surgical procedure that left no outer scarring and resulted in no postoperative pain,” the authors write. “Patients, both male and female, independent of age and body shape, dislike scars, not only for cosmetic reasons but because scars indicate they have undergone treatment because of illness.

Overturning the conventional theory that airborne soot emissions cause regional cooling it has been found that brown clouds of airborne soot can contribute up to a third of atmospheric warming anomalies in the tropics formerly ascribed to CO2 (50 percent of the atmospheric heating caused by CO2 emissions), with its effects ranging as far as the more-temperate American west coast and mountains ranges.

Easily 40 percent of the observed atmospheric warming in the Pacific is due to the shroud of soot drifting eastward from Asia. Prof. V. Ramanathan and fellow researchers are reporting that soot's 2.5 W/cu.m. green house effect is partially offset by its surface dimming effect, such that its net effect is still 1 W/cu.m. With the vast Pacific covering 30 percent of the Earth's surface, aerosol soot - black carbon particulates - plays a significant factor in global warming, potentially 12 percent of all global warming.

Increased solar radiance and decreased snowfall have been implicated as the true culprits in Kilimanjaro's glacier loss. The temperatures on Kilimanjaro's summits almost never rise above freezing, leading researchers to look for other causes for the ongoing glacial recession on Kilimanjaro's peak. Other studies have suggested that deforestation has severely impacted the arboreal microclimates that provide recharge precipitation to Kilimanjaro's glacial packs.

U.N. officials have stated that Kyoto's carbon-credit system is being subverted via cheating while contributing to the destruction of the ozone layer - counter-productive to the Montreal Protocol's goal to preserve it.