07/20/2009 07:00:00
Lori Oliwenstein

Most evolutionary changes happen in tiny increments. But when it comes to traits like the number of wings on an insect, or limbs on a primate, there is no middle ground. How are these sorts of large evolutionary leaps made? According to a team led by scientists at Caltech, such changes may at least sometimes be the result of random fluctuations, or noise (nongenetic variations), working alongside a phenomenon known as partial penetrance.

06/11/2009 18:00:00
Kathy Svitil

The twirling seeds of maple trees spin like miniature helicopters as they fall to the ground. Because the seeds descend slowly as they swirl, they're carried aloft by the wind and dispersed over great distances. Just how the seeds manage to fall so slowly, however, has mystified scientists. In research published in the June 12 Science, researchers from Wageningen University in the Netherlands and Caltech describe the aerodynamic secret of the enchanting swirling seeds.

05/29/2009 07:00:00
Lori Oliwenstein

Theta oscillations are a type of brain rhythm that orchestrates neuronal activity in the hippocampus, a brain area critical for the formation of new memories. For several decades these oscillations were believed to be "in sync" across the hippocampus, timing the firing of neurons like a sort of central pacemaker. A new study conducted by researchers at Caltech shows that, instead, theta oscillations sweep along the length of the hippocampus as traveling waves.  

05/19/2009 07:00:00
Lori Oliwenstein

You can tell without looking whether you've been stuck by a pin or burnt by a match. But how? In research that overturns conventional wisdom, a team of scientists from Caltech and UCSF, have shown that this sensory discrimination begins in the skin at the very earliest stages of neuronal information processing, with different populations of sensory neurons--called nociceptors--responding to different kinds of painful stimuli. 

04/22/2009 07:00:00
Lori Oliwenstein

Some 25 years after the AIDS epidemic spawned a worldwide search for an effective vaccine against the human immunodeficiency virus (HIV), progress in the field seems to have effectively become stalled. The reason? According to new findings from a team of researchers from Caltech, it's at least partly due to the fact that our body's natural HIV antibodies simply don't have a long enough reach to effectively neutralize the viruses they are meant to target.  

04/08/2009 07:00:00
Kathy Svitil

The construction of complex man-made objects--a car, for example, or even a pizza--almost invariably entails what are known as "top-down" processes, in which the structure and order of the thing being built is imposed from the outside (say, by an automobile assembly line, or the hands of the pizza maker).

04/07/2009 07:00:00
Lori Oliwenstein

Scientists at the California Institute of Technology (Caltech) have trained computers to automatically analyze aggression and courtship in fruit flies, opening the way for researchers to perform large-scale, high-throughput screens for genes that control these innate behaviors.

03/23/2009 07:00:00
Lori Oliwenstein

A tiny genetic mutation is the key to understanding why nicotine--which binds to brain receptors with such addictive potency--is virtually powerless in muscle cells that are studded with the same type of receptor. That's according to California Institute of Technology (Caltech) researchers, who report their findings in the March 26 issue of the journal Nature.

03/11/2009 07:00:00
Lori Oliwenstein

Tiny, lightweight fruit flies need to know when it's windy out so they can steady themselves and avoid being knocked off their feet or blown off course. But how do they figure out that it's time to hunker down? Flies have evolved a specialized population of neurons in their antennae that let them know not only when the wind is blowing, but also the direction from which it is coming.

03/09/2009 19:00:00
Kathy Svitil

For the tiny soil-dwelling nematode worm Caenorhabditis elegans, life is usually a situation of feast or famine. Researchers at the California Institute of Technology (Caltech) have found that this worm has evolved a surprisingly optimistic genetic strategy to cope with these disparate conditions--one that could eventually point the way to new treatments for a host of human diseases caused by parasitic worms.

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