Science & Society

Now that the genome sequences of hundreds of bacteria and viruses are known, we can design tests that will rapidly detect the presence of these species based solely on their DNA. These tests can detect a pathogen in a complex mixture of organic material by recognizing short, distinguishing sequences—called DNA signatures—that occur in the pathogen and not in any other species.

Adam Phillippy and colleagues from the University of Maryland, USA, have developed a computer program that can identify these signatures with a higher degree of accuracy than ever before. They describe this new computational system, called Insignia, and the results of its successful application on 46 Vibrio cholerae strains this week in the journal PLoS Computational Biology.

Scientists at the Universitat Autònoma de Barcelona (UAB), in cooperation with the CSIC, have developed a new electro-chemical biosensor which detects the presence, in food, of very small amounts of atrazine –one of the most widely used herbicides in agriculture and which also has very long lasting effects on the environment- as well as antibiotics in food.

The biosensor is faster, more portable and economic than the expensive laboratory methods which are used to detect contaminants, while having a very similar sensitivity. The system has been tested successfully to detect pesticides in samples of drinking water and commercial orange juice, as well as to detect traces of antibiotics in cow's milk.

Imagine being able to rapidly identify tiny biological molecules such as DNA and toxins using less than a drop of salt water in a system that can fit on a microchip.

In a paper appearing next week in the Proceedings of the National Academy of Sciences,* the team proves for the first time that a single nanometer-scale pore in a thin membrane can be used to accurately detect and sort different-sized polymer chains (a model for biomolecules) that pass through or block the channel.


Graphic showing a lipid bilayer membrane (blue) with an alpha-hemolysin nanopore.

Researchers at the University of Illinois have developed a simple and economical technique for imaging and mapping fruit fly chromosomes. This new approach will enable them to construct the first accurate map of the chromosomes and tease out the secrets hidden in their stripes.


Developers of the new approach use a technology called Computer Vision to analyze hundreds of crisp images of the same chromosomes. This will allow the production of a much more precise map of the chromosome bands. Credit: Photo courtesy of Dmitri Novikov

Solar powered mobility scooters could soon be on the streets thanks to the work of a student at The University of Nottingham. Matt Alvey, who is studying Architecture and Environmental Design, says the photovoltaic (solar electric) recharging system will turn the mobility vehicles truly green.

I just got an invitation to attend Science Foo Camp in August 07, a unique meeting organized by Nature, O'Reilly and Google. Based on what I heard from last year's attendees this will be an amazing opportunity to bounce ideas around. I'd like to hear more from others who are going or who attended last year.
As before, we will be inviting around 200 people who are doing particularly interesting work in a wide range of scientific disciplines, as well as in areas of technology and culture that influence, and are influenced by, science. The aim is to encourage cross-fertilization of ideas, creating a unique opportunity to explore topics that transcend traditional boundaries.

Screens that not only display images but also generate their own power are on the horizon.

One of the new display technologies will be suitable for cellphones, making their batteries last far longer than they do now. The other could lead to selfpowered electronic billboards.

Was Chris De Burgh's sexy "Lady in Red," perhaps, ovulating? A new UCLA and University of Wisconsin-Eau Claire study finds evidence that women put more effort into their clothing and grooming during their most fertile periods.

The mouth is a tough environment, which is why dentists do not give lifetime guarantees. Despite their best efforts, a filling may eventually crack under the stress of biting, chewing and teeth grinding, or secondary decay may develop where the filling binds to the tooth. Fully 70 percent of all dental procedures involve replacements to existing repairs, at a cost of $5 billion per year in the United States alone.

Consumers may claim they don't like diet soda because of the taste of artificial sweeteners, but Shelly Schmidt, a University of Illinois professor of food chemistry, thinks people are also influenced by a subtle difference called "mouth-feel." Think body, fullness, thickness; regular soda contains high-fructose corn syrup, diet soda doesn't.

What makes these scientists think mouth-feel is the culprit? For one thing, artificial sweeteners have been greatly improved and extensively studied. "Taste profiles for artificial sweeteners now closely match the one for sucrose, which humans describe as the perfect sweetness," Lee said.