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Up to 64 percent of above-ground biomass in selectively logged forests may consist of dead wood left over from logging damage, argues a paper published this week in Environmental Research Letters. 

As well as being a beautiful species capable of changing its colour, shape and even gender, new research published today shows that parrotfish, commonly found on healthy coral reefs, can also play a pivotal role in providing the sands necessary to build and maintain coral reef islands.

The capacity to deliver continuous electricity for refrigeration is one of the central planks of the modern-day food distribution system.

Using fossil fuel-generated energy to refrigerate and freeze foods around the clock produces a lot of pollution – carbon and greenhouse gas emissions that are warming the global climate, as well as emissions of a range of potentially toxic chemicals that deplete the ozone layer and wind up in our waterways and soil.

El cerebro envejece, al igual que el resto del cuerpo, incluso para aquellos no padecen una enfermedad neurológica, de acuerdo con un Instituto de Medicina.

"Algunos de los cambios que uno observa, no significa que todo ha terminado con tristeza y fatalidad", según dijo al Washington Post Kristine Yaffe, MD, vicepresidente de la comisión.

Si bien el envejecimiento afecta más a unos que a otros, la mayoría de las personas pueden tomar medidas para mejorar su salud, de acuerdo con Yaffe, director y profesor de psiquiatría, neurología y epidemiología en la Universidad de California en San Francisco y director de psiquiatría geriátrica y director de la Clínica de Trastornos de la Memoria en el Centro Médico VA de San Francisco.

How soon after the Big Bang could water have existed? Not right away, because water molecules contain oxygen and oxygen had to be formed in the first stars. Then that oxygen had to disperse and unite with hydrogen in significant amounts. New theoretical work finds that despite these complications, water vapor could have been just as abundant in pockets of space a billion years after the Big Bang as it is today.

“We looked at the chemistry within young molecular clouds containing a thousand times less oxygen than our Sun. To our surprise, we found we can get as much water vapor as we see in our own galaxy,” says astrophysicist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA).