Like the snap of a clothespin, the sudden mixing of closely related species may occasionally provide the energy to impel rapid evolutionary change, according to a new report by researchers from Indiana University Bloomington and three other institutions. Their paper was made available online by Science magazine´s “Science Express” service.
A study of sunflower species that began 15 years ago shows that the sudden mixing and matching of different species´ genes can create genetic super
Blocking the formation of neurons in the hippocampus blocks the behavioral effects of antidepressants in mice, say researchers funded by the National Institutes of Health (NIH). Their finding lends new credence to the proposed role of such neurogenesis in lifting mood. It also helps to explain why antidepressants typically take a few weeks to work, note Rene Hen, Ph.D., Columbia University, and colleagues, who report on their study in the August 8th Science.
“If antidepressants work by stim
Researchers sifting through the indispensable machinery that senses and fixes broken DNA have discovered a new culprit that can induce instability in the genome and thereby set the stage for cancer to develop.
Studies in mice have shown that loss of H2AX, a gene that produces a protein called a histone that is part of the chromosomal structure, can tip the delicate balance of proteins that are curators of the human genome. When H2AX ceases to function properly, lymphomas and solid tu
The universe is gently fading into darkness according to three astronomers who have looked at 40,000 galaxies in the neighbourhood of the Milky Way. Research student Ben Panter and Professor Alan Heavens from Edinburgh University´s Institute for Astronomy, and Professor Raul Jimenez of University of Pennsylvania, USA, decoded the “fossil record” concealed in the starlight from the galaxies to build up a detailed account of how many young, recently-formed stars there were at different periods in the 1
High-level delegates from 30 countries and 22 international organisations agreed at the Earth Observation Summit held last Thursday in Washington to improve cooperation on Earth observation and to remove barriers to the exchange of information between countries and organisations.
ESA already carries out its Earth observation programmes in cooperation with other agencies or countries through mechanisms such as CEOS, the Committee of Earth Observation Satellites and IGOS-P, the Integrated Glo
Multiple sensors on ESA’s Envisat environmental satellite have been used to peer beneath a vast pall of smoke above tropical Borneo and detect fire hotspots – known to add millions of tons of harmful greenhouse gases to the atmosphere.
Fires occur often during the dry season on the South East Asian island of Borneo, but it isn’t only the forests that burn. Lowland tropical peat swamps are formed from layers of woody debris too waterlogged to fully decompose. Slowly deposited over thousands
It´s tricky, this weather business — predicting drought, floods, rain or snow, especially months in advance. But NASA scientists at the National Space Science and Technology Center in Huntsville, Ala., are working to take the guesswork out of long-term prediction.
“We´re researching methods to predict precipitation a season or more in advance,” said Dr. Bob Oglesby, a senior atmospheric scientist at the research center. The key, he said, is understanding how the atmosphere interacts with th
Our earliest ancestors probably behaved in a much more “human” way than most scientists have previously thought, according to a recent study that looked at early hominid fossils from Ethiopia
Previously skeptical, an Ohio State University anthropologist now supports the idea that the minimal size differences between male and female pre-hominids suggest that they lived in a more cooperative and less competitive society.
The evidence centers on the extent of sexual dimorphism – differ
A neat fix for ageing eyes could be tested in humans next year. The treatment, which involves replacing the contents of the lens in the eye with a soft polymer gel, could allow millions of people to throw away their reading glasses.
“At first, we see it being used as an improvement to current cataract surgery,” says Arthur Ho at the University of New South Wales, a key member of the Australian government’s multinational Vision Cooperative Research Centre (Vision CRC) that is working on
Researchers in a University of Chicago lab are peering inside the minds of European starlings to find out how they recognize songs and in the process are providing insights into how the brain learns, recognizes and remembers complex sounds at the cellular level. In a study published in the Aug. 7, 2003, issue of Nature, the researchers show how songs that birds have learned to recognize trigger responses both in individual neurons and in populations of neurons in the bird’s brain.
“We found
Why are elephants bigger than mice? The main reason is that mice have fewer cells. Research published in Journal of Biology this week uncovers a key pathway that controls the number of cells in an animal, thereby controlling its size.
Ernst Hafen and his colleagues from the University of Zürich used fruit flies to investigate the role of the insulin-signalling pathway and in particular a molecule called FOXO. If insulin signalling is reduced, for example by starving developing fly lar
It may be a right-handed world, but recent Purdue University research indicates that the first building blocks of life were lefties – and suggests why, on a molecular level, all living things remain southpaws to this day.
In findings that may shed light on the earliest days of evolutionary history, R. Graham Cooks and a team of Purdue chemists have reported experiments that suggest why all 20 of the amino acids that comprise living things exhibit “left-handed chirality,” which refe
It lacks the warm bedside manner of Marcus Welby or Dr. Kildare, but a high-tech robot being tested at The Johns Hopkins Hospital could be used to link patients with their physicians in a whole new way.
Vaguely resembling a human torso, in a Star Wars R2D2 sort of way, the robot sports a computer screen for a head, a video camera for eyes and a speaker for a mouth. It walks, in a manner of speaking, on three balls, talks, and most importantly, listens. “That´s because the robot is directly
Classification of quantum phenomena critical to high-temp superconductivity
A team of physicists led by researchers at Rice University has developed the first thermodynamic method for systematically classifying quantum phase transitions, mysterious electromagnetic transformations that are widely believed to play a critical role in high-temperature superconductivity.
The new research is described in two papers – one theoretical and one experimental – in the Aug. 8 issue of Phy
Reprogammable microarrays
Physicists at the Georgia Institute of Technology have demonstrated a new optical technique for controlling the flow of very small volumes of fluids over solid surfaces. The technique, which relies on changes in surface tension prompted by optically-generated thermal gradients, could provide the foundation for a new generation of dynamically reprogrammable microfluidic devices.
A paper describing the technique is the cover story for the August 1 iss
The world´s first human test of a vaccine against the prevalent subtype of HIV in sub-Saharan African and Asia, where millions have the virus that causes AIDS, is now under way. The clinical trial uses novel technology pioneered by scientists at the University of North Carolina at Chapel Hill School of Medicine and the U. S. Army Medical Research Institute of Infectious Diseases.
The phase I trial began July 17 at Johns Hopkins University. An adult male, at low risk for HIV infection, was th
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