Dark spots on flower petals are common across many angiosperm plant families and occur on some flowers such as lilies, orchids, and considerable research has been done on the physiological and behavioral mechanisms for how these spots attract pollinators, but what these spots are composed of, how they develop, and how they only appear on some but not all of the ray florets has long been a puzzle. 

Dr. Meredith Thomas from the University of Cambridge and associates from England and South Africa focused on the South African endemic beetle daisy Gorteria diffusa (Asteraceae), which has a unique, raised, dark spot at the base of some of its ray florets to help find deeper answers.  The American Journal of Botany published the results of the study.

If your kids want a Wii, PlayStation or Xbox 360 this holiday season, you may actually have good reason to give them one; it turns out there is some redeeming value in the hours that kids spend transfixed by these video game systems.  A new study in Current Directions in Psychological Science reports that regular gamers are fast and accurate information processors, not only during game play, but in real-life situations as well.

With the publication of a new study in Cellular Microbiology, an international team of researchers has shed new light on the infection strategy of Salmonella, suggesting that scientists will have to reassess their understanding of how the pathogens invade host cells.

Although Salmonella are long-known pathogens, the precise mechanisms they use to infect are incompletely understood. The bacteria inject a protein cocktail into host cells using a molecular syringe, leading to dramatic rearrangements of cytoskeletal filaments below the cell membrane.

The potentially damaging effects of marijuana on young brains may be even worse than previously thought, according to new research conducted by scientists from McGill University. Their new study, published in Neurobiology of Disease, suggests that teenagers who consume marijuana daily face a higher risk of depression and anxiety, and may suffer irreversible neurological effects.

"We wanted to know what happens in the brains of teenagers when they use cannabis and whether they are more susceptible to its neurological effects than adults," explained McGill University researcher Gabriella Gobbi.

New images from NASA's Chandra X-ray Observatory show that the symmetry of supernova remnants, or lack thereof, reveal how the original stars exploded. Astronomers say the discovery is important because it will help them better classify supernovas that exploded hundreds or thousands of years ago. The discovery is reported in a new Astrophysical Journal Letters study.

Astronomers sort supernovas into several categories, or "types", based on properties observed days after the explosion and which reflect very different physical mechanisms that cause stars to explode.  But, since observed remnants of supernovas are leftover from explosions that
occurred long ago, other methods are needed to accurately classify the original supernovas.

In the Dec. 18 issue of Science, Researchers from Tufts University say popular television programs are spreading racial messages to their viewers through biased facial expressions and body language, and it's happening without the audience even knowing it.

The Tufts team studied the prevalence, subtlety and impact of nonverbal race bias in 11 popular weekly scripted television shows. They found that characters on the shows exhibited more negative nonverbal behavior toward black characters than to white characters of the same status. Exposure to "pro-white" (vs. "pro-black") nonverbal bias also increased viewers' race bias, as assessed with reaction-time and self-report measures.