Chemists make the world’s smallest building blocks.
US researchers have made the world’s smallest building blocks. The nanocubes are just a millionth of a millimetre (a nanometre) across 1 . Stacked like bricks, they could make up a range of materials with useful properties such as light emission or electrical conduction.
Many chemists are currently trying to develop molecular-scale construction kits in which the individual components are single molecules to
Researchers at Plant Research International in the Netherlands have achieved a breakthrough in the development of chrysanthemums with resistance to thrips, bringing the ecological cultivation of chrysanthemums a step closer. This is the conclusion of the thesis with which Seetharam Annadana, a Plant Research International guest member of staff from India, recently obtained his doctorate at Wageningen University. Annadana developed new techniques which make possible the genetic modification of two th
When it comes to locating a meal, insect-eating bats generally employ one of two foraging tactics: capturing prey in the air or snatching it from a substrate. Accordingly, the animals use different kinds of echolocation during these activities. Whereas aerial hunters tend toward longer calls with constant frequency, substrate-gleaning species generate short calls that sweep from low to high frequencies (FM echolocation). Less clear, however, is how effective the latter is at distinguishing the prey i
An experiment that University of Chicago physicists conducted just for fun has unexpectedly led them to a new technique for producing nanoscale structures.
The Chicago physicists have built simple electronic devices using the new technique, which precisely controls the growth of metal wires along tiny scaffolds that automatically assemble themselves following nature’s own tendencies.
“This is perhaps the first time that it has been possible to assemble large numbers of parallel, contin
Most climate change research has focused on gradual changes, such as the processes by which emissions of greenhouse gases lead to warming of the planet.
But new evidence shows that periods of gradual change in Earth’s past were punctuated by episodes of abrupt change, including temperature changes of about 10 degrees Celsius, or 18 degrees Fahrenheit, in only a decade in some places.
Severe floods and droughts also marked periods of abrupt change.
A new report from the Nati
Vaccinations may increase death toll.
Inadequate vaccines can the encourage emergence of nastier bugs, placing the unprotected at risk, a new mathematical model shows. The effect could undermine future vaccination programmes.
Many vaccines save people from dying of a disease, but do not stop them carrying and transmitting it. Over a few decades this may cause more virulent strains to evolve, predict Andrew Read and his colleagues of the University of Edinburgh, UK 1
American Society for Cell Biology Meeting, Washington, December 2001
Microscope captures mitochondria bopping to a beat.
An intricate mesh of tubes wiggle, worm-like across the screen. “They’re speeding,” says Tim Richardson proudly, watching mitochondria, the cell’s energy generators, zoom around the cell. His controversial microscopic method is shooting the cell’s innards as they’ve never been seen before.
Live cell imaging has revolutionised cell biology over th
American Geophysical Society Meeting, San Francisco, December 2001
Pressure system secrets could help long range forecasts.
The rise in levels of greenhouse gases has halted an oscillation of air pressures over the Arctic, bringing warmer, wetter winters to Northern Europe, Siberia and Alaska. The shift could get worse with increasing CO2 emissions, delegates heard this week at the American Geophysical Union meeting in San Francisco, California.
The trend is unlikel
American Geophysical Society Meeting, San Francisco, December 2001
The Sun’s violent outbursts have deep and twisted origins.
The Sun’s violent eruptions of material and magnetic energy have deep and twisted origins, researchers told this week’s American Geophysical Union Meeting in San Francisco, California.
These coronal mass ejections (CMEs) cause the aurora, seen at the Earth’s poles, and can knock out spacecraft. An understanding of what drives CMEs may one da
American Society for Cell Biology Meeting, Washington, December 2001
Stem cells’ fates are a multiple choice.
A single stem cell from adult mouse muscle can form enough blood cells to save another animal’s life – and still switch back to making brawn, researchers announced at the Washington meeting of the American Society for Cell Biology this week.
Stem cells found in mashed up muscle can migrate into the bone marrow and make blood cells 1 . Muscle
Satellites have detected the shifting forces that weave the Northern Lights.
A group of four spacecraft has given scientists their first glimpse of the immense electrical circuit above the Earth that creates the shimmering veil of the aurora borealis, or Northern Lights 1 .
In January 2001 the four satellites of the European Space Agency’s Cluster mission encountered a beam of electrons moving away from the Earth near the North Pole. The beam was on the outwa
Astronomers from the University of Pennsylvania, in collaboration with an international team of researchers, have made the first direct detection and measurement of the properties of a dark matter object in the Milky Way.
This observation of a gravitational microlensing event — a temporary increase in the brightness of a background star during the time it takes dark matter to pass in front of it — is reported in today’s issue of Nature.
“By measuring its mass, distance and velocity, w
In any computer’s hard drive, magnetic fields spin electrons this way or that. Now physicists have demonstrated that an electric field can do the same when applied to electrons in semiconductors. And unlike the older magnetic approach, their new device, called a spin gate, is capable of easily imparting a range of spin values. The team’s results, described in a report appearing today in the journal Nature, may one day help to scientists realize the ideal of spintronics—quantum computing based on ele
Mars’ polar ice caps are slowly melting.
The martian ice caps are shrinking. As they are made mostly of frozen carbon dioxide, this evaporation could trigger an increase in Mars’ own greenhouse effect.
Images from the Mars Global Surveyor spacecraft show that ice ridges and escarpments have retreated over the past two years or so. The orbiting probe has also captured the ice thickening and thinning with the passing seasons.
The reason for the change is not yet clea
Dental diary of a teenage hominid aged 1.5 million years.
Our early ancestors never went through the awkward age, suggests a new analysis of dental records. Extended youth may have emerged relatively late in human evolution.
Although apes cut the apron strings at around 12 years, despairing human parents are well aware that their kids take at least 18 years to grow up. The development of this prolonged growth period is seen as a key event in human evolution, allowing extra ti
A new material helps to make clean fuel from water.
Scientists in Japan have found a more efficient way to extract hydrogen, the ultimate ’green’ fuel, from water. They have developed a material that uses sunlight to break water molecules into their constituent elements of hydrogen and oxygen 1 .
The material is not yet efficient enough to be commercially viable, but its inventors believe that it can be improved. If they are right, hydrogen may soon be on tap
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