Wednesday, December 07, 2005

Everything Scientific Vol. VI

It’s back, the penultimate volume of Everything Scientific for the year 2005, and your one-stop for some of the coolest and latest in the world of scientific research.

Biological fuel cells?

From the cover of PNAS is this exciting breakthrough in the world of fuel cells. Hydrogen gas seems promising as a future fuel, suggesting a world where fuel is clean (the only by products are water and CO2), and breaking dependence on fossil fuels. But fuel cell technology is still only developing. A bottleneck is the required use of platinum electrodes. But platinum is expensive, relatively rare, and inactivated by impurities in Hydrogen gas (mostly hydrogen sulfide), and is intolerant to oxygen or carbon monoxide. Could biological systems hold a solution? Biological systems have enzymes (proteins with a catalytic function) called hydrogenases, which carry out dihydrogen oxygenation. These use nickel and iron in their catalytic sites, and efficiently carry out hydrogen-cycling. However, since these enzymes are from mostly anaerobic bacteria, they are intolerant to oxygen. Researchers have now studied a hydrogenase from Ralstonia eutropha , which is exceptionally tolerant to both Carbon monoxide as well as oxygen. They then use these studies to design a fully functional but simple fuel cell device, with this enzyme as the electrocatalyst.

Perhaps biology will provide some more solutions to the world’s fuel problems. Read about the research here, or an editorial here
PNAS, November 22, 2005, 102, 47,16951-16954

Global change, ecosystems and human well being

Most studies of climate or environment change look at little local environments, but they extend across ecosystems and continents. So, to measure the true impact of these changes, data from across regions need to be studied. And human activity must be recognized as essential parts of that ecosystem.

Researchers from various countries across Europe worked together to come up with a detailed “pan-European” study, and took data from 1990 onwards (a decently long time study) and continued the trends to make projections for the year 2080, using the trends and rates seen with existing data. They studied socio-economic, climactic and atmospheric drivers, and used four different models to simulate climate change. Temperature changes slowly but clearly indicated a shift towards warming, but precipitation changes varied across regions. Land use scenarios did not change significantly, but changes in the provision of water were more significant (and would substantially affect the types of crops grown). Southern Europe in particular faced much greater water stress, while changes in snow cover in alpine regions would affect biodiversity, as well as reduce water in summers, with a greater risk of winter floods. The complexity and interrelatedness is fascinating, and is well worth a read (subscription required) here,.
Science 25 November 2005: Vol. 310. no. 5752, pp. 1333 – 1337

Paleontologists have unearthed another spectacular fossil, in the Bavarian region that has been a rich source of these fossils. This is another fossil of Archaeopteryx, the earliest undisputed avian, or bird. But what’s great about this is that it’s almost perfectly preserved, and has the first complete skull as well as a perfectly preserved foot. And that told scientists many new things. It reconfirmed that birds came from non-avian theropod dinosaurs (and not any other reptile). All birds have a fully reversed first toe, so that they can perch on branches, but Archaeopteryx does not have one, strongly suggesting that Archaeopteryx was better suited for living on land than living on trees. The foot also reveals a hyper extensible second toe, very similar to that seen on velociraptors of Jurassic Park fame. Cool.
Science 2 December 2005:Vol. 310. no. 5753, pp. 1483 - 1486

And there’s a bit of controversy as well. No, not that kind. It’s just that the fossil is not going to live in any of the world’s premier fossil museums, but instead is going to a private museum in Thermopolis, Wyoming (which sounds like a one horse, two grocery store town). Perhaps this will make the town boom?

Eat your…..allergy vaccines?

It’s been a desire for many researchers to engineer foods as effective delivery vehicles for therapeutics. One idea long standing (we actually heard about it way back when I was an undergrad) has been to engineer foods with “vaccines” against diseases, enabling a large-scale inoculation using just food. There remain many, many problems….the engineering of a complete vaccine would mean introducing the gene encoding an “attenuated” (weakened) version of the target toxin, which would be expressed in the food itself, and so available to the patient upon consumption. But then this toxin would need to be suitably absorbed and be available in the bloodstream. Obviously, this remains a complicated process with little success thus far.

But researchers in Japan have made some nice progress. They’ve engineered the gene coding for a pollen that causes many allergies in to rice, and the rice expressed this at high levels (nearly 0.5 % of the total protein). They fed this rice to mice, and exposed them to the allergen. Amazingly, the mice appear to have taken up the rice protein, which caused resistance to allergies (reduced histamine release as well as sneezing substantially).

All you allergic lovers of peanuts, help is on its way. Just a few more years now.
PNAS, November 29, 2005, 102, 48, 17525-17530

Theory of Intelligent Deception (ID)

To end this edition of Everything Scientific, I just have to link to this letter to Nature, written by A. R. Palmer. It very nicely points out why “Intelligent Design” is not even a pseudo-science, and brings out why ID proponents have arguments that are ridiculous, and why ID doesn’t fit in to a science classroom. I will quote almost the complete letter (since Nature requires subscription).

”…………. I suggest that ID could be presented as an alternative so long as it is always accompanied by a third option: Intelligent Deception. This hypothesis proposes that the ID movement is motivated by an 'intelligent deceiver'. Individuals who understand how to debate alternative scientific hypotheses would never intentionally promote religious dogma as science. So an intelligent deceiver must be at work, guiding proponents of ID to sow confusion over valid scientific debate. To exclude intelligent deception from debates over ID versus evolution could be considered hypocritical on both legal and moral grounds…….”


Sunil said...

or some thing like that.

Ravi said...

A word of caution- when one says hydrogen as a fuel is breaking dependence on fossil fuels- we forget the biggest fact: currently more than 90% of H2 produced is from Natural Gas, Coal and Oil (All Fossil fuels and byproducts).

Electrolysis, Bio fuels, nuclear energy are being viewed as possible economical sources but thats far from reality. at least now.

Interesting articles Sunil.

Sunil said...

Blokes...that's a very interesting question. Unfortunately, i'm not familiar with that area at i cannot give you an answer. But many, many disciplines are looking to biology for new ideas....a friend of mine got ideas for adhesion looking at insect feet! If i find some thing, i'll definitely update you about it.

R.....bang on. It'll be really nice if you would write a little post on fuel-cells. You're an expert on the topic.....and should be able to explain to us folks what it's really all about, and potential directions for the future etc. An insider's perspective will be wonderful, so i hope you take the bait.