Diatoms -- some of which are so tiny that 30 can fit across the width of a human hair -- are so numerous that they are among the key organisms taking the greenhouse gas carbon dioxide out of the Earth's atmosphere. The shells of diatoms are so heavy that when they die in the oceans they typically sink to watery graves on the seafloor, taking carbon out of the surface waters and locking it into sediments below.

  Genes have the ability to recognize similarities in each other from a distance, without any proteins or other biological molecules aiding the process, according to an exciting new finding. This discovery could explain how similar genes find each other and group together in order to perform key processes involved in the evolution of species.

  A Montana State University lab provides early warnings about biological invaders, serving as producers, home gardeners and Homeland Security. "We are sent mystery samples," says one of the scientists. The team identifies whether the samples are true invading pests or harmless look-alikes.

  Acute and chronic stress can have devastating effects on the brain, and researchers have now pinpointed one receptor that plays a key role in that harmful cycle. Uncontrollable stress is a major contributing factor for neuropsychiatric disorders such as major depression and post-traumatic stress disorders, which have been linked to cellular changes in the hippocampus. The hippocampus is a part of the brain that is particularly susceptible to stress.

  At the end of January, more than 200,000 crop varieties from Asia, Africa, Latin America and the Middle East -- drawn from vast seed collections maintained by the Consultative Group on International Agricultural Research -- will be shipped to a remote island near the Arctic Circle, where they will be stored in the Svalbard Global Seed Vault, a facility capable of preserving their vitality for thousands of years.

  Sure, you're more likely to give things a favorable evaluation when you're happy, and a negative evaluation when you're sad. But how does mood influence your choices among items? Researchers found that when happy consumers were asked to withhold judgment until all options were presented, they tended to prefer the last option they saw.

  Medical experts believe they could have found the key to turning back the brain's biological clock and reverse the effects of dementia and memory loss. Pioneering research has shown that regular exposure to safe low level infra-red light can improve learning performance and kick-start the cognitive function of the brain.

  Researchers have found the brain region that controls the decision to halt your midnight exploration of the refrigerator and commence enjoyment of that leftover chicken leg. In their experiments, the researchers presented monkeys with a choice of touch targets on a computer screen, requiring the monkeys to spend time exploring which target would trigger a juice reward. Once the monkeys discovered the reward target, the researchers then gave the animals a period during which they could repeatedly touch the reward target to obtain more juice.

  Istanbul is at such high risk for a devastating earthquake that engineers at Purdue University and the Republic of Turkey have come up with a bold new proposal: build a second city. A second, satellite city would provide immediate refuge to inhabitants of the old city in the event of a catastrophic earthquake and soften such an event's effects on the nation's economy.

  Inflammation of the middle ear (otitis media) is one of the most common pediatric ailments. Young children are particularly prone to otitis media as their Eustachian tubes, which regulate the pressure in the middle ear, have not yet fully developed. In many instances it is accompanied by an acute ear infection and can be resolved by a course of antibiotics.

  The average temperature for the contiguous U.S. in 2007 is officially the tenth warmest on record, according to data from scientists at NOAA's National Climatic Data Center in Asheville, N.C. The agency also determined the global surface temperature last year was the fifth warmest on record.

  Laughter is the best medicine. We've heard the expression time and again. For decades, researchers have explored how humor helps patients relieve stress and heal. Now, researchers have taken it one step further, with new research on how humor helps medical professionals cope with their difficult jobs. She also looked at how humor affects the elderly and how it can increase communication in the workplace and in the classroom.

  The opening of gorillas and chimpanzees reserves for tourism is often portrayed as the key to conserving these endangered great apes. There are also however serious concerns that tourism may expose wild apes to infection by virulent human diseases.

  About nine percent of teenagers may have metabolic syndrome, a clustering of risk factors that put them on the path toward heart disease and diabetes in adulthood. This shocking statistic represents some of the first concentrated efforts to define and measure metabolic syndrome in children and adolescents -- a necessary starting point for combating the problem, but one that has proven even trickier in youth than it has been in adults.