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6 March 2014 1:04 pm ,
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Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
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ScienceShot: World's Oldest Wood
11 August 2011 2:00 pm
Talk about an old-growth forest. Newly described fossils push back the appearance of wood by at least 10 million years. The fossils, including one from 407-million-years-old rocks in France, preserve the remains of stems about 12 centimeters long. The size and arrangement of cells in the cores of the stems, and particularly the presence of long, thin cells (arrows) that span several rings of cells and extend like rays from the center toward the outer rims, are characteristic of wood, researchers report online today in Science. The plants' small size, as well as the presence of thick-walled cells elsewhere in the stems, suggests that wood evolved to efficiently transport water from the soil into the plant. At the time these plants lived, atmospheric concentrations of carbon dioxide were decreasing, which in turn decreased the water-use efficiency of the plants and boosted their need for water, the scientists say. Although the first plants sporting wood were small, subsequent species quickly took advantage of wood's structural strength: In just a few million years, some had attained treelike stature.
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