Martian soil capable of supporting plant life
NASA’s Mars Phoenix Lander determined that nutrients required for plant growth are present in a soil a sample taken from the planet’s northern arctic plain.
While the discovery indicates the potential for life, it leaves no sign of its existence in the past or possibilities in the future. The surface of Mars is cold, dry and receives massive amounts of ultraviolet radiation – conditions that likely prohibit plant growth. It’s possible, however, that different conditions existed in the past and could have supported plant life, provided the other requirements – air and water – were also present.
In a separate experiment, the lander heated a soil sample to 1,800 degrees Fahrenheit causing it to release water vapor – indicating that the soil had interacted with water at some point in the past. The Phoenix, which landed on the Martian surface May 25, is capable of collecting and analyzing three more soil samples. (source: nytimes.com)
Uranium-eating molecule could help make nuclear energy green
Scientists at the University of Edinburgh in Scotland have invented a uranium-eating molecule that could help solve the problem of disposing of nuclear waste.
When uranium is processed through a reactor, only 5 percent of its energy is extracted. U.S. power plants currently don’t reprocess the fuel because uranyl, the most common uranium ion, is difficult to remove from the used fuel rods. The newly invented molecule, called a macrocycle, looks like a set of jaws and will eat, or engulf, the uranyl molecule when they come into contact. This weakens uranyl’s structure and causes it to react with compounds more easily extracted from the nuclear waste.
There are still some problems, however, as the uranium-eating molecule doesn’t work very well in water or air. Nevertheless, researchers remain optimistic that this discovery is a step in the right direction toward making nuclear power a green alternative energy source. (source: popsci.com)
Designer enzyme might help prevent HIV
A California research company has made an important type of white blood cell more resistant to HIV by custom designing an enzyme that disrupts a gene called CCR5, which produces a protein that binds to HIV.
The enzyme is the product of ongoing research into the long-held theory that tailor-made enzymes could attach to any spot on the human genome and cut or alter disease-causing gene segments. The enzyme is made of zinc-finger proteins, which control natural gene activity. They have been engineered to sever a particular DNA sequence, thereby disabling the gene.
There is a risk associated with the process, however, because if there happens to be a sequence of DNA similar to the one for which the enzyme was designed, it could misfire and destroy the wrong gene. Researchers say this is unlikely and in the vast majority of instances when this would occur, the gene destroyed wouldn’t be necessary for human survival. (source: nature.com)
Science Scene is compiled by ALYSOUN BONDE. She can be reached at email@example.com