As the male túngara frog serenades female frogs from a pond, he creates watery ripples that make him easier to target by rivals and predators such as bats, according to researchers from The University of Texas at Austin, the Smithsonian Tropical Research Institute (STRI), Leiden University and Salisbury University.

A túngara frog will stop calling if it sees a bat overhead, but ripples continue moving for several seconds after the call ceases. In the study, published this week in the journal Science, researchers found evidence that bats use echolocation — a natural form of sonar — to detect these ripples and home in on a frog. The discovery sheds light on an ongoing evolutionary arms race between frogs and bats.

The linchpin location of the "Star Wars" franchise was the planet Tatooine, home to both Luke Skywalker and Obi-Wan Kenobi. It, along with its twin suns, appeared in every movie of the franchise except "The Empire Strikes Back".

How would such a planet, orbiting two stars, form? There are few environments more extreme than a binary star system, if you are forming a planet. 

Kepler-34(AB)b has some answers, according to a new study. Like Tatooine, Kepler-34(AB)b is a circumbinary planet, its orbit encompasses two stars. Since powerful gravitational perturbations from two stars lead to destructive collisions that grind down planetary material, the existence of such planets can be difficult to explain.

A new study conservatively estimates that one in five women with ovarian cancer has inherited genetic mutations that increase the risk of the disease, according to research at Washington University School of Medicine in St. Louis.

Most women in the study would have been unaware of a genetic predisposition to ovarian cancer because they didn't have strong family histories that suggested it.

Silicon-based electronics has certain limits, in the physical sense of the word: this type of circuit can never become "nano" because of the physical laws governing the flow of electrons. This imposes a halt to the process of miniaturization of electronic devices. One of the possible solutions is to use molecules as circuits, but their poor conduction capabilities make them unlikely candidates. There is, however, a possible way around this, which was investigated in a recent paper published in Proceedings of the National Academy of Sciences (PNAS) by an international research team that includes Ryan Requist, Erio Tosatti and Michele Fabrizio of the International School for Advanced Studies (SISSA) in Trieste.

Humans are able to smell sickness in someone whose immune system is highly active within just a few hours of exposure to a toxin, according to new research published in Psychological Science, a journal of the Association for Psychological Science.

According to researcher Mats Olsson of Karolinska Institutet in Sweden, there is anecdotal and scientific evidence suggesting that diseases have particular smells. People with diabetes, for example, are sometimes reported to have breath that smells like rotten apples or acetone.

Being able to detect these smells would represent a critical adaptation that would allow us to avoid potentially dangerous illnesses. Olsson wondered whether such an adaptation might exist already at an early stage of the disease.

In two studies in the January 24 issue of Science, researchers at Albert Einstein College of Medicine of Yeshiva University used advanced imaging techniques to provide a window into how the brain makes memories. These insights into the molecular basis of memory were made possible by a technological tour de force never before achieved in animals: a mouse model developed at Einstein in which molecules crucial to making memories were given fluorescent "tags" so they could be observed traveling in real time in living brain cells.