Through photosynthesis, green plants and cyanobacteria are able to transfer sunlight energy to molecular reaction centers for conversion into chemical energy with nearly 100-percent efficiency. Speed is the key - the transfer of the solar energy takes place almost instantaneously so little energy is wasted as heat. How photosynthesis achieves this near instantaneous energy transfer is a long-standing mystery that may have finally been solved.
A study led by researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley reports that the answer lies in quantum mechanical effects. Results of the study are presented in the April 12, 2007 issue of the journal Nature.
"We have obtained the first direct evidence that remarkably long-lived wavelike electronic quantum coherence plays an important part in energy transfer processes during photosynthesis," said Graham Fleming, the principal investigator for the study. "This wavelike characteristic can explain the extreme efficiency of the energy transfer because it enables the system to simultaneously sample all the potential energy pathways and choose the most efficient one."
WASHINGTON - Researchers have decoded genetic material from a 68 million-year-old Tyrannosaurus rex, an unprecedented step once thought impossible.
Iridescent, silvery blue clouds at the edge of space that may be connected to global warming will be studied by a NASA spacecraft set to launch on 25 April.
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| ©Hampton University
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| Noctilucent clouds were first observed in 1885, two years after the Krakatoa eruption. But most volcanic eruptions do not spew material high enough in the atmosphere to seed the formation of the icy clouds
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The Aeronomy of Ice in the Mesosphere (AIM) mission will be the first satellite dedicated to studying the enigmatic phenomenon of "noctilucent", or night-shining clouds.
An adolescent female Tyrannosaurus rex died 68 million years ago, but its bones still contain intact soft tissue, including the oldest preserved proteins ever found, scientists say.
For thousands of years, the evidence lay at the bottom of Brown's Lake, buried in thick, gooey mud.
MSNBCTue, 10 Apr 2007 23:10 UTC
Temperature increase could be shrinking the planet's polar ice caps. Shifting dust storms on Mars might be contributing to global warming there that is shrinking the planet's southern polar ice caps, scientists say.
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| ©Christensen
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| These two views of Mars are derived from the MGS Thermal Emission Spectrometer (TES) measurements of global broadband visible and near-infrared reflectance, also known as albedo.
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Comment: Uhm, yes, it's due to dust storms and warming on Earth is due to all those groovy cars driving around. The data, however, certainly indicates that whatever is 'going on' is doing so on a solar system basis, not a global one.
Water has been identified for the first time in the atmosphere of a planet outside the Solar System, it was revealed tonight.
The discovery increases the chances of life being found among the stars.
According to common historical accounts, the "Skull of Destiny" was found in 1927 by the English explorer Fredrik A Mitchell-Hedges among Mayan ruins, in Lubaantun. Other voices declare that the investigator bought the piece in a Sothebys auction that took place in London in the year 1943.
Whatever the case, the crystal rock skull is cut and polished so perfectly that it appears to be an invaluable work of art. However, to be certain of the first hypothesis (that the skull is Mayan in origin) we are faced with a series of penetrating questions.
The Skull of Destiny is, in a certain sense, a technical impossibility. With a weight of around 5kg (11 lbs) and being a perfect replica of a female skull, it has a finish that would have been impossible to achieve without relative modern methods, according to scientists; methods that, of course, the Mayan culture is not known to have possessed.
University of Cincinnati (UC) neuroradiologists believe a brain imaging approach that combines standard magnetic resonance imaging (MRI) scans with specialized contrast-enhanced techniques could lead to more effective diagnoses in patients with difficult-to-detect blood clots in veins of the brain.
James Leach, MD, reports these findings in the April issue of the American Journal of Neuroradiology. This is the first study to correlate the clinical importance of data gleaned from standard MRI scans and detailed contrast-enhanced imaging techniques in patients with chronic thrombosis (blood clots) in veins of the brain.
"Detailed contrast-enhanced techniques produce more defined distinctions between abnormal and normal veins in the membrane around the brain," explains Leach, a neuroradiologist and associate professor at UC and principal investigator of the study. "Evaluating patients using a combination of imaging tools could give us a better understanding of the disease process."
sing a quartet of space observatories, University of Maryland astronomers may have cracked a 45-year mystery surrounding two ghostly spiral arms in the galaxy M106.
The Maryland team, led by Yuxuan Yang, took advantage of the unique capabilities of NASA's Chandra X-ray Observatory, NASA's Spitzer Space Telescope, the European Space Agency's XMM-Newton X-ray observatory, and data obtained almost a decade ago with NASA's Hubble Space Telescope.
M106 (also known as NGC 4258) is a stately spiral galaxy 23.5 million light-years away in the constellation Canes Venatici. In visible-light images, two prominent arms emanate from the bright nucleus and spiral outward. These arms are dominated by young, bright stars, which light up the gas within the arms. "But in radio and X-ray images, two additional spiral arms dominate the picture, appearing as ghostly apparitions between the main arms," says team member Andrew Wilson of the University of Maryland. These so-called "anomalous arms" consist mostly of gas.
Comment: Uhm, yes, it's due to dust storms and warming on Earth is due to all those groovy cars driving around. The data, however, certainly indicates that whatever is 'going on' is doing so on a solar system basis, not a global one.