New findings about the causes of mad cow disease show that sometimes it may be genetic. "We now know it's also in the genes of cattle," said Juergen A. Richt, Regents Distinguished Professor of Diagnostic Medicine and Pathobiology at Kansas State University's College of Veterinary Medicine.
Until several years ago, Richt said, it was thought that the cattle prion disease bovine spongiform encephalopathy -- also called BSE or mad cow disease -- was a foodborne disease. But his team's new findings suggest that mad cow disease also is caused by a genetic mutation within a gene called Prion Protein Gene. Prion proteins are proteins expressed abundantly in the brain and immune cells of mammals.
The research shows, for the first time, that a 10-year-old cow from Alabama with an atypical form of bovine spongiform encephalopathy had the same type of prion protein gene mutation as found in human patients with the genetic form of Creutzfeldt-Jakob disease, also called genetic CJD for short. Besides having a genetic origin, other human forms of prion diseases can be sporadic, as in sporadic CJD, as well as foodborne. That is, they are contracted when people eat products contaminated with mad cow disease. This form of Creutzfeldt-Jakob disease is called variant CJD.
Science & Technology
The precise timing of the origin of life on Earth and the changes in life during the past 4.5 billion years has been a subject of great controversy for the past century.
The principal indicator of the amount of organic carbon produced by biological activity traditionally used is the ratio of the less abundant isotope of carbon, 13C, to the more abundant isotope, 12C. As plants preferentially incorporate 12C, during periods of high production of organic material the 13C/12C ratio of carbonate material becomes elevated. Using this principle, the history of organic material has been interpreted by geologists using the 13C/12C ratio of carbonates and organics, wherever these materials can be sampled and dated.
While this idea appears to be sound over the last 150 million years or so, prior to this time there are no open oceanic sediment records which record the 13C/12C ratio, and therefore, geologists are forced to use materials associated with carbonate platforms or epicontinental seas.
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| ©NASA |
| A new study examines changes in carbon isotope ratios over the past 10 million years at sites off the Bahamas (Atlantic Ocean), the Maldives (Indian Ocean), and Great Barrier Reef (Pacific Ocean). |
The principal indicator of the amount of organic carbon produced by biological activity traditionally used is the ratio of the less abundant isotope of carbon, 13C, to the more abundant isotope, 12C. As plants preferentially incorporate 12C, during periods of high production of organic material the 13C/12C ratio of carbonate material becomes elevated. Using this principle, the history of organic material has been interpreted by geologists using the 13C/12C ratio of carbonates and organics, wherever these materials can be sampled and dated.
While this idea appears to be sound over the last 150 million years or so, prior to this time there are no open oceanic sediment records which record the 13C/12C ratio, and therefore, geologists are forced to use materials associated with carbonate platforms or epicontinental seas.
Nicosia, Cyprus - The top archeologist in Cyprus says a chance dig has unearthed a "very rare" 2,500-year-old marble sarcophagus in the shape of a woman.
Hackers have mounted an attack on the Large Hadron Collider, raising concerns about the security of the biggest experiment in the world as it passes an important new milestone.
A new touch-sensitive nerve fibre responsible for the sense of pleasure experienced during stroking has been described at a UK conference today. The nerves tap into a human's reward pathways, and could help explain why we enjoy grooming and a good hug, a neuroscientist has explained.
His team used a stroking machine to reveal the optimal speed and pressure for the most enjoyable caress. The research was presented at the British Association Science Festival. Mothers stroke their children, monkeys groom group members, and we all enjoy a massage, but what is it about stroking and rubbing that we find so enjoyable?
His team used a stroking machine to reveal the optimal speed and pressure for the most enjoyable caress. The research was presented at the British Association Science Festival. Mothers stroke their children, monkeys groom group members, and we all enjoy a massage, but what is it about stroking and rubbing that we find so enjoyable?
Harvest Moon: This weekend's full Moon (Sept. 14/15) has a special name--the Harvest Moon. It's the full moon closest to the northern autumnal equinox (Sept. 22). In years past, farmers depended on the light of the Harvest Moon to gather ripening crops late into the night. Post-Edison, we appreciate it mainly for its beauty.
Be alert in the nights ahead for Harvest Moon halos:
Be alert in the nights ahead for Harvest Moon halos:
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| ©David Cartier |
| Halos are not purely daytime happenings. Look for them whenever a bright moon is veiled by thin cirrus cloud. A full or nearly full moon is best.
22º halos often encircle the moon. More rarely, because the moon is relatively dim, it is possible to see moondogs and other halos. Colours are faint or non existent because their light is barely strong enough to excite the colour sensors of our eyes. Much smaller coloured rings sometimes surround the moon. These are not a halo but a corona produced by the diffraction of light by the water droplets of clouds. And of course moonlight creates a rainbow although to the unaided eye it is usually a wan creature devoid of colour. |
Stars without enough mass to turn into exploding supernovae end their lives blowing away most of their mass in a non-explosive, but intense stellar wind. Only a hot stellar core remains in the form of a white dwarf; the rest of the star is dispersed into the interstellar medium, enriching it with chemically processed elements, such as carbon, that is found in all living organisms on Earth.
These elements were cooked in the stellar furnace during a stellar life span covering billions of years. The high-energy radiation from the hot white dwarf makes the blown gas to shine for a short period of time, and the result is one of the most colourful and beautiful astronomical objects: a planetary nebula.
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| ©Howard Bond (STScI), NASA |
| IC 3568 |
These elements were cooked in the stellar furnace during a stellar life span covering billions of years. The high-energy radiation from the hot white dwarf makes the blown gas to shine for a short period of time, and the result is one of the most colourful and beautiful astronomical objects: a planetary nebula.
When the world's land was congealed in one supercontinent 240 million years ago, Antarctica wasn't the forbiddingly icy place it is now. But paleontologists have found a previously unknown amphibious predator species that probably still made it less than hospitable.
The species, named Kryostega collinsoni, is a temnospondyl, a prehistoric amphibian distantly related to modern salamanders and frogs. K. collinsoni resembled a modern crocodile, and probably was about 15 feet in length with a long and wide skull even flatter than a crocodile's.
In addition to large upper and lower teeth at the edge of the mouth, temnospondyls often had tiny teeth on the roof of the palate. However, fossil evidence shows the teeth on the roof of the mouth of the newly found species were probably as large as those at the edge of the mouth.
"Its teeth, compared to other amphibians, were just enormous. It leads us to believe this animal was a predator taking down large prey," said Christian Sidor, a University of Washington associate professor of biology and curator of vertebrate paleontology at the Burke Museum of Natural History and Culture at the UW.
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| ©Christian Sidor |
| Teeth are visible along the edge of this temnospondyl fossil, and also can be seen spaced out across the palate roof about one-third of the way up in the photograph. |
The species, named Kryostega collinsoni, is a temnospondyl, a prehistoric amphibian distantly related to modern salamanders and frogs. K. collinsoni resembled a modern crocodile, and probably was about 15 feet in length with a long and wide skull even flatter than a crocodile's.
In addition to large upper and lower teeth at the edge of the mouth, temnospondyls often had tiny teeth on the roof of the palate. However, fossil evidence shows the teeth on the roof of the mouth of the newly found species were probably as large as those at the edge of the mouth.
"Its teeth, compared to other amphibians, were just enormous. It leads us to believe this animal was a predator taking down large prey," said Christian Sidor, a University of Washington associate professor of biology and curator of vertebrate paleontology at the Burke Museum of Natural History and Culture at the UW.
The impact of Hurricane Ike has reached out into space and delayed the planned Friday arrival of a Russian cargo ship at the international space station.
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| ©Reuters / Stephen Brusatte / Columbia University |
| Crurotarsans skulls |
Thanks to a big stroke of luck 200 million years ago, dinosaurs beat out a fearsome group of creatures competing for the right to rule the Earth, scientists said on Thursday.
Dinosaurs appeared about 230 million years ago, during the Triassic Period, and competed for 30 million years with a group of reptiles called crurotarsans, cousins of today's crocodiles that grew to huge sizes and looked a lot like dinosaurs.
