GEN-ERIC News

Unlike their sisters in the animal kingdom, human females don’t openly advertise their ovulation. But even without a human version of the baboon’s bright pink behind, signs of fertility sneak out, according to several studies. Subconsciously, women dress more provocatively and men find them prettier when it’s prime time for conception. And a report from the University of New Mexico demonstrates that the cyclic signs have economic consequences. Psychologist Geoffrey Miller and colleagues tapped the talent at local gentlemen’s clubs and counted tips made on lap dances. Dancers made about $70 an hour during their peak period of fertility, versus about $35 while menstruating and $50 in between. Miller links the wage fluctuations to changes in body odor, waist-to-hip ratio, and facial features. Despite operating at the upper limits of flirtatiousness already, he says there may also be subtle shifts in their behavior—"how they talk and move when enticing a customer to buy a dance, and how they perform the dance itself.” Women on the pill averaged $37 (and had no performance peak) versus $53 for women off-pill. The contraceptive produces hormonal cues indicating early pregnancy, not an enticing target for a would-be suitor. Birth control could lead to many thousands of dollars lost every year.

Using sunlight to liberate hydrogen from water is an appealing way to generate a clean-burning fuel from a renewable energy source. As a result, scientists have examined a variety of materials over the years in search of a suitable catalyst to accelerate the water-splitting reaction. Several candidates show some level of promise, yet each material suffers from shortcomings that would limit its applications. For example, some catalysts absorb solar radiation inefficiently, exhibit low activity, or are unstable or costly. Now, a team of researchers at the Max Planck Institutes for Bioinorganic Chemistry and for Coal Research, in Germany, report that titanium disilicide (TiSi2)—an abundant and inexpensive semiconductor not known previously to be a water-splitting catalyst—separates water into hydrogen and oxygen when reactors containing the powdered catalyst are illuminated with simulated sunlight.

By mimicking a brick-and-mortar molecular structure found in seashells, University of Michigan researchers created a composite plastic that’s as strong as steel but lighter and transparent. It’s made of layers of clay nanosheets and a water-soluble polymer that shares chemistry with white glue. Engineering professor Nicholas Kotov almost dubbed it “plastic steel,” but the new material isn’t quite stretchy enough to earn that name. Nevertheless, he says its further development could lead to lighter, stronger armor for soldiers or police and their vehicles. It could also be used in microelectromechanical devices, microfluidics, biomedical sensors and valves and unmanned aircraft. Kotov and other U-M faculty members are authors of a paper on this composite material, “Ultrastrong and Stiff Layered Polymer Nanocomposites,” published in the Oct. 5 edition of Science. The scientists solved a problem that has confounded engineers and scientists for decades: Individual nano-size building blocks such as nanotubes, nanosheets and nanorods are ultrastrong. But larger materials made out of bonded nano-size building blocks were comparatively weak. Until now.