Sunday, October 27, 2013

Dolly - First mammal to be cloned

Dolly - First mammal to be cloned

Dolly - First mammal to be cloned


Dolly was a female domestic sheep, and the first mammal to be cloned from an adult somatic cell, using the process of nuclear transfer. She was cloned by Ian Wilmut, Keith Campbell and colleagues at the Roslin Institute, part of the University of Edinburgh. She was born on 5 July 1996 and she lived until the age of six, at which point she died from a progressive lung disease. The cell used as the donor for the cloning of Dolly was taken from a mammary gland, and the production of a healthy clone therefore proved that a cell taken from a specific part of the body could recreate a whole individual.

Dolly was created using the technique of somatic cell nuclear transfer, where the cell nucleus from an adult cell is transferred into an unfertilised oocyte (developing egg cell) that has had its nucleus removed. The hybrid cell is then stimulated to divide by an electric shock, and when it develops into a blastocyst it is implanted in a surrogate mother. Dolly was the first clone produced from a cell taken from an adult mammal. The production of Dolly showed that genes in the nucleus of such a mature differentiated somatic cell are still capable of reverting to an embryonic totipotent state, creating a cell that can then go on to develop into any part of an animal. Dolly's existence was announced to the public on 22 February 1997.

Dolly lived her entire life at the Roslin Institute in Edinburgh. There she was bred with a Welsh Mountain ram and produced six lambs in total. Her first lamb, named Bonnie, was born in April 1998. The next year Dolly produced twin lambs Sally and Rosie, and she gave birth to triplets Lucy, Darcy and Cotton in the year after that. In the autumn of 2001, at the age of four, Dolly developed arthritis and began to walk stiffly, but this was successfully treated with anti-inflammatory drugs.

On 14 February 2003, Dolly was euthanized because she had a progressive lung disease and severe arthritis. A Finn Dorset such as Dolly has a life expectancy of around 11 to 12 years, but Dolly lived to be only six years of age. A post-mortem examination showed she had a form of lung cancer called Jaagsiekte, which is a fairly common disease of sheep and is caused by the retrovirus JSRV. Such lung diseases are a particular danger for sheep kept indoors, and Dolly had to sleep inside for security reasons.

After cloning was successfully demonstrated through the production of Dolly, many other large mammals have been cloned, including horses and bulls. Cloning may have uses in preserving endangered species and may become a viable tool for reviving extinct species. Cloning of domesticated animals could be important in the future production of transgenic livestock.

Wednesday, October 23, 2013

Gold growing in eucalyptus trees


Gold growing in eucalyptus trees

Gold growing in eucalyptus trees

The discovery, the first of its kind in the world and the first time gold particles have been found in living material.

Geoscientists in Perth, Australia have discovered gold particles in the leaves, twigs and bark of eucalyptus trees, claiming a "eureka" moment that could revolutionise gold mining. CSIRO researchers believe the trees, sitting on top of gold deposits buried deep underground, suck up the gold in their search for moisture during times of drought.

Scientists said, "To actually see the gold particles in the leaves was quite a eureka moment for us and they were not expecting it"

The trees appear to be telling scientists what is happening under the earth's surface. The particular trees that were researched upon appear to be bringing up gold from 30 metres depth, which is about the equivalent of a 10-storey building.

The research group used the CSIRO's Maia detector for x-ray elemental imaging at the Australian Synchrotron in Melbourne to analyse extremely small particles at high resolution.

The portions of gold are about one-fifth the diameter of a human hair. The researchers said they have also found gold in the leaves of other trees, such as the Acacia mulga.

Gold existed not only in trees but in shrubs that are growing beneath the trees as well.

Monday, October 21, 2013

Li-Fi to replace Wi-Fi in China


Li-Fi to replace Wi-Fi in China

Li-Fi to replace Wi-Fi in China

Chinese scientists have successfully developed a new cheaper way of getting connected to internet by using signals sent through light bulbs instead of radio frequencies as in 'Wi-Fi', a move expected to radically change process of online connectivity.

Four computers can be connected to internet through one- watt LED bulb using light as a carrier instead of traditional radio frequencies, as in Wi-Fi.

Under the new discovery dubbed as 'Li-Fi', a light bulb with embedded microchips can produce data rates as fast as 150 megabits per second, which is 20 times faster than the average broadband connection in China.