|
|
|
Big bang theorists share Nobel physics prize
The Nobel prize for physics was awarded last week to two scientists who helped to prove that the universe began with the big bang. John Mather of the Nasa Goddard Space Flight Centre in Maryland and George Smoot of the University of California, Berkeley, will share the 10m kronor (£720,000) prize.
The big bang theory states that the universe was born in an explosion almost 14bn years ago. Today we see that explosion as a background of microwave radiation present throughout the universe.
Prof Smoot told Associated Press: “The discovery was sort of fabulous, it was an incredible milestone.” Prof Mather said the prize was a “rare and special honour”. The scientists were involved in designing and building the Cosmic Background Explorer (Cobe), a Nasa satellite launched in 1989 to measure microwave background radiation. Tiny variations in temperature told scientists how “clumpy” the universe is and how matter began to form stars and galaxies.
Profs Mather and Smoot published their results, which described the temperature variations, in the early 1990s. In the process they transformed cosmology from a mainly theoretical pursuit into an era of direct observation and measurement. Michael Rowan-Robinson, president of the Royal Astronomical Society, said that Mather and Smoot’s work was “among the most significant discoveries in astronomy of the past century”.
US scientist Roger Kornberg has been awarded the Nobel prize in chemistry for his studies of how cells take information from genes to produce proteins. Dr Kornberg, whose father, Arthur Kornberg, won a Nobel prize in medicine in 1959, was the first scientist to create an actual picture of how transcription works at a molecular level in the important group of organisms called eukaryotes (organisms whose cells have a well-defined nucleus).
Disturbances in that process, known as transcription, are involved in many human illnesses, including cancer, heart disease and various kinds of inflammation. Understanding transcription also is vital to the development of treatments using stem cells.
Dr Kornberg, a member of the Stanford University school of medicine in Palo Alto, California, described how information is taken from genes and converted to molecules called messenger RNA. These molecules shuttle the information to the cells’ protein-making machinery, the Royal Swedish Academy of Sciences said in its citation.
A statement from the academy said: “Transcription is necessary for all life. This makes the detailed description of the mechanism that Roger Kornberg provides exactly the kind of ‘most important chemical discovery’ referred to by Alfred Nobel in his will.”
Dr Kornberg, 59, is the lone winner of the 2006 chemistry prize, and the fifth American to win a Nobel prize this year. So far, all the prizes — medicine, physics and chemistry — have gone to Americans.
Two US geneticists who discovered a way to silence individual genes shared £724,337 and the kudos of the Nobel prize in physiology or medicine recently.
Andrew Fire, 47, a former Cambridge post-doc who is now at Stanford University, and Craig Mello, 45, at the University of Massachusetts Medical School, were awarded the prize for discovering RNA interference (RNAi), a tool that scientists hope will lead to new treatments for HIV and cancer.
Their publication in the journal Nature in 1998 described how strands of genetic material called RNA could be used to block the activity of selected genes. The paper led to a flurry of tests to see if the technique could be used to treat serious medical conditions, including Huntingdon’s, Alzheimer’s and Parkinson’s disease.
The award is among the quickest to be granted, at just eight years after the research was first published. The Nobel committee at the Karolinska Institute in Stockholm said the pair had “discovered a fundamental mechanism for controlling the flow of genetic information”.
The desire to overeat in obese people is controlled by the same part of the brain that controls cravings for drugs in addicts, according to research. Scientists have found that compulsive eating is regulated by the emotional centres in the brain, leading some people to overeat in an attempt to feel better.
The results were published in the Proceedings of the National Academy of Sciences. “This study opens new territory in understanding how the body and brain connect to each other, and how this connection is tied to obesity," said Gene-Jack Wang of the Centre for Translational Neuro-imaging at the Brookhaven National Laboratory, New York.
“We were able to simulate the process that takes place when the stomach is full, and for the first time we could see the pathway from the stomach to the brain that turns ‘off’ the brain’s desire to continue eating.”
Dr Wang’s team studied seven obese volunteers implanted with gastric stimulators for up to two years. This pacemaker-like device stimulates the vagus nerve, causing the stomach to expand and send a message to the brain to stop eating. Gastric stimulators have successfully been used in obese patients to reduce appetite.
Each volunteer was placed in a positron emission tomography (PET) scanner and brain activity measured when the gastric stimulator was on and then off. “We found that implantable gastric stimulators induced significant changes in metabolism in brain regions associated with controlling emotions, effectively shutting down these obese subjects’ desire to eat,” said Dr Wang.
The changes were most noticeable in the hippocampus area of the brain. This is linked to emotional behaviour, learning and memory, movement, and processing of sensory information. In people addicted to drugs the hippocampus also plays a role in maintaining the memory of drug experiences. — Dawn/The Guardian News Service
|
|
|
|
