- News Home
17 April 2014 12:48 pm ,
Vol. 344 ,
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
ScienceShot: Why Sperm Swim in Circles
11 May 2010 7:01 pm
Perhaps it's no surprise that sperm often swim in circles. They must rely on a tail smaller than the width of a human hair to conquer an obstacle course with 200-million-to-one odds. Until now, scientists blamed sperms' circular locomotion on their erratic, asymmetric tail propulsion. But where they swim might be more important than how they swim, according to a study published online tomorrow in the Journal of the Royal Society Interface. Researchers simulated sperm cell migration and found that if the surrounding fluids (such as semen or vaginal secretions) are viscous enough, the sperm tails will buckle in the current, trapping the cells into a circular loop they can't escape even if the cells swim perfectly. Knowing how to trap sperm in the right places could improve the effectiveness of in vitro fertilization and other reproductive technologies, experts say.
See more ScienceShots.