Δευτέρα 24 Δεκεμβρίου 2012

ScienceDaily: Top Environment News

ScienceDaily: Top Environment News


Paleo-ocean chemistry: New data challenge old views about evolution of early life

Posted: 23 Dec 2012 12:27 PM PST

A research team has tested a hypothesis in paleo-ocean chemistry, and proved it false. Many researchers attribute the delayed diversification and proliferation of eukaryotes to very low levels of zinc in seawater. But after analyzing marine black shale samples from North America, Africa, Australia, Asia and Europe, ranging in age from 2.7 billion years to 580 million years old, the researchers found that the shales reflect high seawater zinc availability.

Smaller Colorado River projected for coming decades, study says

Posted: 23 Dec 2012 12:27 PM PST

Some 40 million people depend on the Colorado River Basin for water but warmer weather from rising greenhouse gas levels and a growing population may signal water shortages ahead. In a new study, climate modelers predict a 10 percent drop in the Colorado River's flow in the next few decades, enough to disrupt longtime water-sharing agreements between farms and cities across the American Southwest.

Decision to give a group effort in the brain

Posted: 23 Dec 2012 12:27 PM PST

A monkey would probably never agree that it is better to give than to receive, but they do apparently get some reward from giving to another monkey. During a task in which rhesus macaques had control over whether they or another monkey would receive a squirt of fruit juice, three distinct areas of the brain were found to be involved in weighing benefits to oneself against benefits to the other, according to new research.

First goat genome sets a good example for facilitating de novo assembly of large genomes

Posted: 23 Dec 2012 12:26 PM PST

Researchers report the first genome sequence of domestic goat, setting a good example for facilitating de novo assembly of large genomes.

Nutrient-sensing enzymes key to starvation response and survival in newborn mammals

Posted: 23 Dec 2012 12:24 PM PST

In the perilous hours immediately after birth, a newborn mammal must survive the sudden loss of food supply from its mother. Under normal circumstances, newborns mount a metabolic response to ward off starvation until feeding occurs. This survival response involves a process of controlled breakdown of internal energetic sources known as autophagy. Although autophagy has been well documented, the key mechanistic regulators of autophagy in vivo have remained poorly understood. Researchers have now discovered that a family of nutrient-sensing enzymes, dubbed Rag GTPases, modulates the activity of the mTORC1 protein complex, whose inhibition is essential for autophagy and survival in newborns.

Study shows rapid warming on the West Antarctic ice sheet

Posted: 23 Dec 2012 12:24 PM PST

In a discovery that raises further concerns about the future contribution of Antarctica to sea level rise, a new study finds that the western part of the ice sheet is experiencing nearly twice as much warming as previously thought.

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