A team of the US researchers has found searching the internet stimulates brain activity in the elderly and middle-aged and may help keep their minds sharp.
The study was carried out by scientists at the University of California at Los Angeles (UCLA) and published in the latest edition of the American Journal of Geriatric Psychiatry.
It said, the web triggers key centres in the brain that control decision-making and complex reasoning and may help stimulate and possibly improve brain function.
“The study results are encouraging, that emerging computerised technologies may have physiological effects and potential benefits for middle-aged and older adults,” said Dr Gary Small, the principal investigator of the study. “Internet searching engages complicated brain activity, which may help exercise and improve brain function,” said Small, a professor at UCLAs Semel Institute for Neuroscience and Human Behaviour.
The study's authors noted that their findings are the latest to suggest that complex activity that keeps the mind engaged, such as crossword puzzles, may help keep the brain healthy.
The UCLA researchers said they tested 24 neurologically normal research volunteers between the ages of 55 and 76, half with experience searching the internet and half with no experience.
The study participants performed web searches and book-reading tasks while undergoing functional magnetic resonance imaging (fMRI) scans, which record brain-circuitry changes.
They all showed significant brain activity during book reading and web searching, but the internet-savvy group registered a twofold increase in brain activation during web use when compared with those with little internet experience.
They said the web-savvy group also registered greater activity in the frontal, temporal and cingulated areas of the brain, which control decision-making and complex reasoning.
“Our most striking finding was that Internet searching appears to engage a greater extent of neural circuitry that is not activated during reading — but only in those with prior Internet experience,” said Small.
“A simple, everyday task like searching the web appears to enhance brain circuitry in older adults, demonstrating that our brains are sensitive and can continue to learn as we grow older,” he added. — AFP
Obesity Caused By Deficit Of Brain 'Pleasure Centres'
Obese people may have a diminished ability to experience the pleasure of eating, prompting them to overindulge to boost their satisfaction, according to a study.
The study, published in the journal Science, found that obese individuals may have fewer pleasure receptors in their brains, requiring them “to take in more of a rewarding substance such as food or drugs to experience the same level of pleasure as other people,” said Eric Stice, a psychology researcher at the University of Texas (UT) at Austin and lead author of the study.
In a throwback to humankinds evolutionary past, the human brain releases the “pleasure chemical” dopamine, a reward to the body for consuming life-sustaining nutrition.
But the researchers theorise that weak “reward centres” in the brain prompt obese people to eat more.
“The research reveals obese people may have fewer dopamine receptors, so they overeat to compensate for this reward deficit,” said Stice, who has studied eating disorders and obesity for almost two decades.
Although past research has shown that biological factors play a major part in obesity, the study is one of the first to positively identify factors that increase peoples weight gain risk in the future.
The researchers from UT, worked alongside scientists from the Oregon Research Institute, and brain scientists from the Yale University School of Medicine, Connecticut.
Using a technique called functional Magnetic Resonance Imaging (fMRI), researchers examined the extent to which pleasure receptors in individuals were activated in response to a taste of chocolate milkshake versus a tasteless solution.
The participants were next tested for the presence of a genetic variation linked to a lower number of the dopamine receptors. Researchers then tracked changes in the test participants' body mass index over a one-year period. The results, said Stice, are key for understanding weight gain, and to helping at-risk individuals.
“Although people with decreased sensitivity of reward circuitry are at increased risk for unhealthy weight gain, identifying changes in behaviour or pharmacological options could correct this reward deficit to prevent and treat obesity,” he said.— AFP
SPACE
Trouble For Hubble
NASA's efforts to get the ailing Hubble Space Telescope working again have hit a snag, and engineers are trying to figure out their next step.
Officials had hoped to have the 18-year-old observatory back in business, after it stopped sending pictures some weeks ago. But a pair of problems cropped up, and now recovery operations are on hold. Flight controllers at Goddard Space Flight Centre in Greenbelt, Maryland, began the lengthy process of restoring data transmission.
The problems involved one of Hubble's cameras and the command and data-handling system for science instruments, said Nasa spokeswoman Susan Hendrix. That system failed late last month and prevented the telescope from capturing and beaming down data used to create the stunning pictures of the cosmos for which Hubble is known.
Because of the breakdown, Nasa delayed its final Hubble repair mission by shuttle astronauts that was set for October. The mission will not happen until at least February, possibly later.
The recovery efforts involved switching to a backup channel for the command and data-handling system; the backup channel had been dormant since the telescope was launched in 1990.
“If it's a commanding error and they figure it out, then they can bring it back up,” Hendrix said. “But if its more serious, theyre going to need a little more time to troubleshoot.”— AP
ENVIRONMENT
Francophonie To Cut Co2 Emissions
Seventy French-speaking nations and regional governments pledged to help cut global greenhouse gas emissions to half by 2050, at the close of the 12th Francophonie summit.
The group reaffirmed its backing of the United Nations Framework Convention on Climate Change and the Kyoto Protocol.
It said it would draft a “concerted francophone position” for upcoming climate change conferences in Poznan in December and Copenhagen in 2009.
From the start, the question of climate change had been a contentious issue at the Francophone summit, with co-hosts Canada and its province Quebec clashing over the wording of a resolution.
In a final declaration, the Francophonie pledged to “cooperate so that all of our countries can develop national policies to meet a common objective of reducing by at least 50 per cent global greenhouse gas emissions by 2050...” Thus, France and Canada are now set on a path toward a common climate change front.
At a press conference, Canada's Prime Minister Stephen Harper also announced 100 million dollars in aid for poorer countries most affected by warming.
Omar Bongo Ondimba, president of Gabon in west central Africa, said on behalf of the delegates, that they were also preoccupied with access to clean drinking water, water for agriculture, and management of cross-border waters.
They also put forth strategies to preserve the CongoBasin forest, the world's second largest tropical forest, and on biodiversity. — AFP
OCEANOLOGY
Arctic On Thin Ice
Autumn temperatures in the Arctic are at record levels, the Arctic Ocean is getting warmer and less salty as sea ice melts, and reindeer herds appear to be declining, researchers reported.
“Obviously, the planet is interconnected, so what happens in the Arctic does matter” to the rest of the world, Jackie Richter-Menge of the Cold Regions Research and Engineering Laboratory said in releasing the third annual Arctic Report Card.
The report, compiled by 46 scientists from 10 countries, looks at a variety of conditions in the Arctic.
The region has long been expected to be among the first areas to show impacts from global warming, which the Intergovernmental Panel on Climate Change says is largely a result of human activities adding carbon dioxide and other gases to the atmosphere.The report noted that 2007 was the warmest year on record in the Arctic, leading to a record loss of sea ice. This year's sea ice melt was second only to 2007.
Rising temperatures help melt the ice, which in turn allows more solar heating of the ocean. That warming of the air and ocean affects land and marine life, and reduces the amount of winter sea ice that lasts into the following summer.
The study also noted a warming trend on Arctic land and an increase in greenness as shrubs move north into areas that were formerly permafrost. While the warming continues, the rate in this century is less than in the 1990s due to natural variability, the researchers said.
In addition to global warming, natural cycles of warming and cooling occur, and a warm cycle in the 1990s added to the temperature rise. Now with cooler cycles in some areas the rise in temperatures has slowed down, but James Overland, an oceanographer at the National Oceanic and Atmospheric Administrations Pacific Marine Environmental Laboratory in Seattle, Washington, expects it will speed up again when the next natural warming cycle comes around.
Furthermore, the Arctic Ocean continued to warm and freshen due to ice melt. This was accompanied by an “unprecedented” rate of sea level rise of nearly 0.1 inch (0.254 centimetre) per year. Reindeer herds that had been increasing since the 1970s are now showing signs of levelling off or beginning to decline. Also, goose populations are increasing as they expand their range within the Arctic.— AP
PALAEONTOLOGY
Fresh Evolutionary Insights
An extraordinary fish that existed 375 million years ago had unique features in its head that helped pave the way for vertebrate animals to live on land, scientists said.
Scientists for the first time described features in the underside of the skull of Tiktaalik roseae, the so-called “walking fish” discovered in the Canadian Arctic in 2004. It is considered an important transitional animal in the evolution of fish into amphibians, the first land-dwelling vertebrates.
The findings showed that the migration from water to land was more complicated than merely having a fish's fins transform into legs, the scientists wrote in the journal Nature.
The head showed changes from more primitive fish that helped adapt to the new feeding and breathing conditions presented by a terrestrial environment, the scientists said.
Like some other fish of its time, it had gills and lungs.
“Its not to say that Tiktaalik itself is a terrestrial animal. It spent most of its time in water, for sure,” Jason Downs of the Academy of Natural Sciences in Philadelphia, one of the researchers, said in a telephone interview.
“So what its really demonstrating is that many of these changes that are occurring and things that we once associated with terrestrial life are turning out, in fact, to be adaptations for life in shallow water settings that Tiktaalik might had found himself in,” Downs added.
It likely inhabited the mudflats of freshwater flood plains of a subtropical environment. It was a large aquatic predator, measuring up to 9 feet (2.7 metres) long, with sharp teeth and a flattened head like a crocodile and unlike primitive fish.
It may have been able to exit the water for short jaunts on land. Tiktaalik has features of some of the more primitive fish it lived with as well as features of the first four-legged amphibians that lived on land. Its fins had discernible wrists and elbows in an evolutionary step toward legs that could be used to walk around on dry land. The underside of the skull remained encased in rock at the time Tiktaaliks discovery was announced. Using a needle to remove rock grain by grain under a microscope, scientists have painstakingly studied the inside of the creatures skull. — Reuters
AT A GLANCE
“Big Bang” Collider Glitch Was Electrical Fault
The technical problem that forced the shut-down of a huge particle collider built to probe the origins of the universe was a faulty electrical connection between two of the accelerator's magnets, CERN said.
The European Organisation for Nuclear Research (CERN) was forced to shut down the biggest scientific experiment ever conducted last month only 10 days after starting up its Large Hadron Collider (LHC) because of a helium leak in its tunnel.
White Space Backers See New Devices In A Year
Opening unused US television channels to wireless devices, an idea endorsed by communications regulators this week, could spark development of faster devices with features such as high-definition video within a year, backers said.
The US Federal Communications Commission late on released a highly-anticipated report backing the feasibility of opening up 'white spaces' - unused pockets of the spectrum. These airwaves will become available when the US broadcasters are required to move completely to digital television next year.
Study Finds Brain Chemical Linked To Grief
Scientists have pinpointed a key brain chemical involved in dealing with the sudden loss or long-term separation of a partner, they said.
The finding in a type of rodent called a prairie vole could lead to potential treatments for people suffering severe depression-like symptoms after losing a partner, Oliver Bosch of the University of Regensburg in Germany and his colleagues said.
Ancient Bones Show Tuberculosis Older Than Thought
Scientists have discovered tuberculosis in 9,000 year-old human bones found submerged off Israels coast - evidence the disease is at least 3,000 years older than previously thought, researchers said. The findings show how tuberculosis has evolved over thousands of years and provides a better understanding of ways it may change in the future, the researchers said.
Doctors Warn Of Rash From Mobile Phone Use
Doctors baffled by an unexplained rash on people's ears or cheeks should be on alert for a skin allergy caused by too much mobile phone use, the British Association of Dermatologists said.
Citing published studies, the group said a red or itchy rash, known as “mobile phone dermatitis,” affects people who develop an allergic reaction to the nickel surface on mobile phones after spending long periods of time on the devices.
Diabetes Not A Risk Factor For Parkinson's Disease
Although the likelihood of having diabetes diagnosed is increased around the time Parkinson's disease is identified, diabetes does not appear to increase the risk of Parkinson's disease, according to findings published in Diabetes Care.
Some studies have found a positive association between diabetes and Parkinson's disease, Dr Jane A. Driver of HarvardMedicalSchool, Boston, and colleagues point out.
It has been suggested that diabetes might promote Parkinsons disease through various pathways, including suppressing neurotransmitter levels, inflammation, oxidative stress, and cerebrovascular disease.
Study Points To Strong New Class Of Antibiotics
Three naturally occurring antibacterial compounds hold promise for a new class of antibiotics, offering hope for fresh weapons against infection at a time when older drugs are losing their punch, researchers said.
The new agents, reported in the journal Cell, may even provide a quicker cure for tuberculosis, which could help people stick to the prescribed therapy better and reduce the development of resistant strains. ---Reuters
