This Week's News
Our dear friend, Dolly the sheep has died at the young age of 6 1/2 years old. She died after developing a pnumonia-like lung infection that is common to older sheep. She had also developed arthritis. The life expectancy of most sheep is over 12 years. Dolly, like other cloned animals, had telomeres of shorter than normal length. Telomeres are the 'caps' on the ends of DNA that protect DNA from damage. Recent research has shown that people with longer telomeres might expect to live longer than people whose telomeres are of shorter length. Read more
here.
Researchers who use a test known as the Morris water maze to determine the cognitive abilities of mice might actually be getting erroneous test results. The water maze consists of a cylindrical container holding a milky bath and a submerged platform. The water is normally held at a temperature of 20 degrees Celsius. Mice are dropped into the bath, and then timed to see how long they take to find the platform. The faster the mice find the platform, the better their memory is thought to be. The maze was originally designed for much heartier rats. So, it turns out that the water temperature is simply too cold for the mice. After only a couple of swims, the mice become visibly hypothermic. Any errant behavior or apparent confusion in the maze is likely due to the cold temperature rather than actual memory impairment. Read more
here.
The bedbug seems to have an interesting mating system... called 'traumatic insemination' by evolutionary physiologists from the U.K., the male bedbug has a needle-like penis that he injects into the female's abdomen. Then the female fights back with viscious immune cells that destroy approximately most of the male's sperm. However, the male of the species seems to have evolved a way around the female's lack of cooperation. It seems that the female's defensive immune system only attacks the sperm of the first male to mate with her. There are also sensory hairs on the surface of the male's penis that detect whether or not there is any sperm already inside the female. If the male detects sperm, he only injects half of his normal delivery. So, each successive male to mate with a female drops off less and less sperm. Researchers believe that this system has evolved in order to conserve the precious sperm resources. Read more
here and
here.
Surprising, but true. Researchers have recorded neurons in the area of mice brains that is involved with sensing pheromones for the very first time. Not knowing what to expect, researchers installed tiny electrode wires into the area of mouse brain called the accessory olfactory bulb (AOB), and recorded what the neurons did when the robo-mice met other mice from different genetic backgrounds. They found that the AOB responds to pheromones from mice in much the same way that humans respond to faces. In other words, the AOB creates a neuronal image of an individual based on its chemical signal. That signal doesn't imply specific traits like gender or genetic history, but rather a composite of many traits that make up an individual. Read more
here.
Two new genes for intelligence have been discovered by researchers in the U.K. and California. The first, CTSD, is thought to be involved in early brain development, and relies on the activity of a previously known gene called IGFR2. The second gene, CHRM2, is associated with Alzheimer's disease. It seems that people with a mutation in CHRM2 have lower IQ's than people with out the mutation... but, only by a couple of points. Read more
here.
The polar ice caps on Mars have been determined to be mostly water. Researchers at Caltech University in California put the planets caps through several hypothetical permutations based on differing proportions of carbon dioxide and water. The closest match to existing satellite images confirms that the proportion weighs heavily in favor of water. This is good news for the Mars program. Read more
here.
Ibuprofen might interfere with aspirin. A study of 7000 patients taking aspirin to reduce the possibility of heart attack showed that those who also took ibuprofen were twice as likely to die during the study period than patients only taking aspirin. It is thought that ibuprofen interferes with aspirin's ability to thin the blood. Read the story
here.
current science news posted by Kirsten at 2/18/2003 08:28:00 PM
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