Science & Technology
They found that plants are able to grow in these regions because they are able to take advantage of iron minerals in Saharan dust storms. This allows them to use organic or 'recycled' material from dead or decaying plants when nutrients such as phosphorous - an essential component of DNA - in the ocean are low.
Professor George Wolff, from the University's Department of Earth and Ocean Sciences, explains: "We found that cyanobacteria - a type of ancient phytoplankton - are significant to the understanding of how ocean deserts can support plant growth. Cyanobacteria need nitrogen, phosphorous and iron in order to grow. They get nitrogen from the atmosphere, but phosphorous is a highly reactive chemical that is scarce in sea water and is not found in the Earth's atmosphere. Iron is present only in tiny amounts in sea water, even though it is one of the most abundant elements on earth.
The fluffy-looking galaxy, officially named Messier 101, is dominated by a mishmash of spiral arms. In Spitzer's new view, in which infrared light is color coded, the galaxy sports a swirling blue center and a unique, coral-red outer ring.
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| ©NASA/JPL-Caltech/STScI |
| The Pinwheel galaxy, otherwise known as Messier 101, sports bright red edges in this new infrared image from NASA's Spitzer Space Telescope. |
A new paper appearing July 20 in the Astrophysical Journal explains why this outer ring stands out. According to the authors, the red color highlights a zone where organic molecules called polycyclic aromatic hydrocarbons, which are present throughout most of the galaxy, suddenly disappear.
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| ©Stephen Alvarez |
| Asteroids and comets in nearby space pose a constant threat to our planet. Can we avert catastrophe the next time around? |
The first sign of the threat was no more than a speck on a star-streaked telescope image. Just after 9 p.m. on June 18, 2004, as twilight faded over Kitt Peak National Observatory in Arizona, David Tholen was scanning for asteroids in an astronomical blind spot: right inside Earth's orbit, where the sun's glare can overwhelm telescopes. Tholen, an astronomer from the University of Hawaii, knew that objects lurking there could sometimes veer toward Earth. He had enlisted Roy Tucker, an engineer and friend, and Fabrizio Bernardi, a young colleague at Hawaii, to help. As they stared at a computer, three shots of the same swath of sky, made a few minutes apart, cycled onto the screen. "Here's your guy," said Tucker, pointing at a clump of white pixels that moved from frame to frame.
Tholen reported the sighting to the International Astronomical Union's Minor Planet Center, a clearinghouse for data on asteroids and comets. He and Tucker hoped to take another look later that week, but they were rained out, and then the asteroid disappeared from view.
Comment: A society that wants to vaccinate itself from the ponerizing influence of psychopaths in positions of power will likely have to use a variety of means including brain scans and psychological tests to discover these clever mimics of normal humans. However, there certainly is no government currently mature enough to use and not abuse the science necessary to such an approach.
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| ©The National Museum of Fine Arts in Sweden |
| The Swedish king Karl XI on his horse Brilliant after the battle in Lund, December 4, 1676, painted by David Klöcker Ehrenstrahl. |
The white horse is an icon for dignity which has had a huge impact on human culture across the world. An international team led by researchers at Uppsala University has now identified the mutation causing this spectacular trait and show that white horses carry an identical mutation that can be traced back to a common ancestor that lived thousands of years ago.
The study is interesting for medical research since this mutation also enhance the risk for melanoma. The paper is published on July 20 on the website of Nature Genetics.
The great majority of white horses carry the dominant mutation Greying with age. A Grey horse is born coloured (black, brown or chestnut) but the greying process starts already during its first year and they are normally completely white by six to eight years of age but the skin remains pigmented. Thus, the process resembles greying in humans but the process is ultrafast in these horses. The research presented now demonstrates that all Grey horses carry exactly the same mutation which must have been inherited from a common ancestor that lived thousands of years ago.
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| ©SPX File Photo |
| Southern Yemen. |
As part of a larger program of archaeological research, Michael Harrower from the University of Toronto and The Roots of Agriculture in Southern Arabia (RASA) team explored the Wadi Sana watershed documenting 174 ancient irrigation structures, modeled topography and hydrology, and interviewed contemporary camel and goat herders and irrigation farmers.
"Agriculture in Yemen appeared relatively late in comparison with other areas of the Middle East, where farming first developed near the end of the last ice age about 12,000 years ago," says author Michael Harrower, Department of Anthropology, University of Toronto.
"It's clear early farmers in Yemen faced unique environmental and social opportunities and challenges. Our findings show farming in southern Yemen required runoff diversion technologies that were adapted to harness monsoon (summer) runoff from the rugged terrain along with new understandings of social landscapes and rights to scarce water resources."
One study, published in the July 17 issue of Nature, shows that vast regions of the ancient highlands of Mars, which cover about half the planet, contain clay minerals, which can form only in the presence of water.
Volcanic lavas buried the clay-rich regions during subsequent, drier periods of the planet's history, but impact craters later exposed them at thousands of locations across Mars. The data for the study derives from images taken by the Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM, and other instruments on the orbiter.
"The big surprise from these new results is how pervasive and long-lasting Mars' water was, and how diverse the wet environments were," said Scott Murchie, CRISM principal investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.











Comment: The threat to Earth by asteroids and comet fragments has been increasing dramatically, please see our 'must-read' Comet Series for more information.