The biological term "symbiosis" refers to what economists and politicians usually call a win-win situation: a relationship between two partners which is beneficial to both. The mutualistic association between acacia plants and the ants that live on them is an excellent example: The plants provide food and accommodation in the form of food bodies and nectar as well as hollow thorns which can be used as nests. The ants return this favor by protecting the plants against herbivores. Researchers at the Max Planck Institute for Chemical Ecology in Jena, Germany, have now found that ants also keep harmful leaf pathogens in check. The presence of ants greatly reduces bacterial abundance on surfaces of leaves and has a visibly positive effect on plant health.

PROVIDENCE, R.I. – Julie Boergers, Ph.D., a psychologist and sleep expert from the Bradley Hasbro Children's Research Center, recently led a study linking later school start times to improved sleep and mood in teens. The article, titled "Later School Start Time is Associated with Improved Sleep and Daytime Functioning in Adolescents," appears in the current issue of the Journal of Developmental & Behavioral Pediatrics.

CORVALLIS, Ore. – In a finding that overturns the conventional view that large old trees are unproductive, scientists have determined that for most species, the biggest trees increase their growth rates and sequester more carbon as they age.

In a letter published today in the journal Nature, an international research group reports that 97 percent of 403 tropical and temperate species grow more quickly the older they get. The study was led by Nate L. Stephenson of the U.S. Geological Survey Western Ecological Research Center. Three Oregon State University researchers are co-authors: Mark Harmon and Rob Pabst of the College of Forestry and Duncan Thomas of the College of Agricultural Sciences.

If you work in politics or culture, you are probably quick to attribute fast-food consumption as the major factor causing rapid increases in childhood obesity. Scholars the University of North Carolina at Chapel Hill report that fast-food consumption is simply a byproduct of a much bigger problem: poor all-day-long dietary habits that originate in children's homes.

The break-up of the supercontinent Gondwana about 130 Million years ago could have led to a completely different shape of the African and South American continent - with an ocean south of today's Sahara desert.

Researchers from the University of Sydney and the GFZ German Research Centre for Geosciences used plate tectonic and three-dimensional numerical modeling to highlight the importance of rift orientation relative to extension direction as key factor deciding whether an ocean basin opens or an aborted rift basin forms in the continental interior.

Low oxygen conditions often persist inside tumors, but they are sufficient to initiate a molecular chain of events that transform breast cancer cells from being rigid and stationery to mobile and invasive.

A recent study highlighted the importance of hypoxia-inducible factors in promoting breast cancer metastasis.