Science & Technology
Boosted by physical and mental exercise, neural stem cells continue to sprout new neurons throughout life, but the exact function of these newcomers has been the topic of much debate. Removing a genetic master switch that maintains neural stem cells in their proliferative state finally gave researchers at the Salk Institute for Biological Studies some definitive answers.
Without adult neurogenesis - literally the "birth of neurons" - genetically engineered mice turned into "slow learners" that had trouble navigating a water maze and remembering the location of a submerged platform, the Salk investigators report in the Jan. 30 Advance Online Edition of Nature. The findings suggest that, one day, researchers might be able to stimulate neurogenesis with orally active drugs to influence memory function, the researchers say.
New research shows that people with blue eyes have a single, common ancestor. A team at the University of Copenhagen have tracked down a genetic mutation which took place 6-10,000 years ago and is the cause of the eye colour of all blue-eyed humans alive on the planet today.
What is the genetic mutation
"Originally, we all had brown eyes", said Professor Eiberg from the Department of Cellular and Molecular Medicine. "But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a "switch", which literally "turned off" the ability to produce brown eyes". The OCA2 gene codes for the so-called P protein, which is involved in the production of melanin, the pigment that gives colour to our hair, eyes and skin. The "switch", which is located in the gene adjacent to OCA2 does not, however, turn off the gene entirely, but rather limits its action to reducing the production of melanin in the iris - effectively "diluting" brown eyes to blue. The switch's effect on OCA2 is very specific therefore. If the OCA2 gene had been completely destroyed or turned off, human beings would be without melanin in their hair, eyes or skin colour - a condition known as albinism.
Wed, 30 Jan 2008 15:02 CET
Electrical stimulation of areas deep within the brain could improve memory, early research suggests.
A team of doctors in Canada stumbled upon the finding while attempting to treat a morbidly obese man through deep brain stimulation (DBS).
The electrical stimulation caused the patient to experience vivid memories.
The findings, reported in the Annals of Neurology
, potentially pave the way for electrical stimulation to treat disorders such as Alzheimer's disease.
|The brain's limbic system was stimulated
In September 2007, I was offered the role of 'Social Media Manager' at a company in Cape Town, South Africa which I took without much hesitation. I knew my job would focus on the 'general' projects such as proposals, running campaigns and devising social strategies for clients who had something they wanted to generate a buzz about online. Little did I know I would be training up the other team members completely from scratch on the subject but I can confidently say it was the most enjoyable part of the job. Here are 15 of the most important things about social media marketing I taught to those completely new to the approach.
Astronomers used to think that brief stellar eruptions called novae generated massive amounts of dust. But new observations of a well known nova system called RS Ophiuchus shows that isn't the case. The dust was there already, and a nova blast just clears it all away.
Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., have obtained the first images of asteroid 2007 TU24 using high-resolution radar data. The data indicate the asteroid is somewhat asymmetrical in shape, with a diameter roughly 250 meters (800 feet) in size. Asteroid 2007 TU24 will pass within 1.4 lunar distances, or 538,000 kilometers (334,000 miles), of Earth on Jan. 29 at 12:33 a.m. Pacific time (3:33 a.m. Eastern time).
|These low-resolution radar images of asteroid 2007 TU24 were taken over a few hours by the Goldstone Solar System Radar Telescope in California's Mojave Desert. Image resolution is approximately 20-meters per pixel. Next week, the plan is to have a combination of several telescopes provide higher resolution images.
Fri, 18 Jan 2008 19:37 CET
Researchers have unravelled a genetic puzzle that explains why black sheep have become a dying breed on one Scottish island.
They say the findings suggest natural selection can act on single-gene traits like coat colour in a way that's more complex than generally thought.
The Black Death that decimated populations in Europe and elsewhere during the middle of the 14th century may not have been a blindly indiscriminate killer as previously believed.
An analysis of 490 skeletons from a London cemetery for Black Death victims shows the infection did not affect everyone equally, researchers say.
Jan. 25, 2008 -- Well water of the tiny Canadian town of Gypsumville, Manitoba (population 65) has been poisoned by an extraterrestrial
The invader: A meteorite which struck
down almost a quarter-billion years ago, creating the 25-mile-wide (40-kilometer) Lake Martin impact crater.
Albuquerque, N.M. - An asteroid that exploded over Siberia a century ago, leaving 800 square miles of scorched or blown down trees, wasn't nearly as large as previously thought, a researcher concludes, suggesting a greater danger for Earth.