Intermediate Word: pergola (a) a domed structure, usually atop a roof (b) a diagonal band on which one's medals are displayed (c) a board game (d) planted-covered arched arbor
Difficult Word: - porphyry (a) purple-colored plant (b) type of seashell (c) large feldspar crystals in an igneous matrix (d) skin disease
|Alien microbes could survive crash-landing - Nature Left: Bacteria carried on a meteorite would experience around a million times atmospheric pressure if they crashed into Earth. Bugs inside lumps of rock can survive impacts at speeds of more than 11 kilometres per second, say the researchers 1. The work also shows that bacteria could survive crashing into icy surfaces such as Jupiter's moons Europa and Ganymede. Mark Burchell and his colleagues at the University of Kent, Canterbury, have put panspermia to the test by firing lumps of porous ceramic infiltrated with bacteria into targets. During impact, the bacteria are crushed by up to a million times atmospheric pressure. The survival rate for an ice target was about ten times higher, so Burchell and colleagues think that it's not just Earth and Mars that could have swapped life. The icy moons of Jupiter, for instance, at least one of which, Europa, has a sub-surface ocean of water, could seed one another. Or a planet could re-seed itself if, as some have suggested might have happened on the early Earth|
spaceship set for test flight
- Nature Left: Developers
hope that this inflatable pod could soon go to Mars.
An inflatable lifeboat could one day ferry stranded astronauts back to Earth, if a prototype's test flights are successful next month. The re-entry vehicle weighs just 130 kilograms and is being developed to carry cargo back from the International Space Station (ISS). But its inventors believe that it could also let astronauts bail out of the space station, or deliver robots to the surface of Mars. An inflatable heat shield will protect the ship and slow it down. A second, larger inflatable emerges from the rear of the craft to act as a parachute, reducing its speed to about 35 kilometres per hour before it hits the ground. The surface is made from a tough, flexible polymer coated with a paint that can withstand temperatures of around 900 °C. The exact composition of the paint is a closely guarded secret, says Joachim Thäter, an engineer at RRSS.
|Hair-raising stem cells confirmed in mouse skin - Nature Adult mouse skin contains stem cells that can generate skin and hair. Although the result has been hinted at before, the latest work is the first to prove that the cells are true stem cells, with the capacity to form new tissues. It's hoped the discovery will lead to treatments for baldness and burns. The researchers took individual cells and grew them up into hundreds of thousands of identical copies, then grafted them into a wound on the back of a hairless mouse. The cells grew to form patches of fur, including skin, follicles, hair, and oil-producing glands. "The hairs are quite dense. They look just like a normal fur coat," says Fuchs. She says the work is the first to show that individual cells isolated from hair follicles can form identical copies of themselves, and produce multiple types of tissue when grafted - making them true stem cells. The team's results are published in Cell1.|