Stress may affect fertility: Stop worrying about having a baby. A new study suggests that long-term stress may decrease fertility in women. Researchers analyzed levels of two stress hormones, cortisol and alpha-amylase, in 401 women who were trying to have a baby over four years. “There was no association of cortisol with fertility. But those whose alpha-amylase levels were in the highest third, a sign of longstanding stress, had more than double the risk of infertility,” even when researchers controlled for other factors. The study’s authors suggest that women who are having trouble becoming pregnant might benefit from stress-reduction techniques like yoga, meditation and mindfulness. 

Your nose can smell at least 1 trillion scents: Here’s something to sniff at. A new study suggests that the human nose can detect at least one trillion different scents. This number is significantly higher than previous estimates. “While scientists estimate that human beings can discriminate between several million different colors and almost half a million different sounds, they have long assumed that we can distinguish perhaps 10,000 different odors.” To arrive at the new number, researchers used 128 different odorant molecules to create smell mixtures, which they then tested on volunteers. The new information suggests that our noses, which contain about 400 different odor receptors, are “far more sensitive than any other organ in the body.”