Influenza A viruses have been known to appear, disappear, and reappear in cycles lasting decades. The influenza virus that caused an epidemic in Europe and North America in 1951 “disappeared”, but then reappeared in 1977, causing the infamous Russian flu epidemic.

In a recent Earth science conference in Beijing, Michael Raupach, a carbon-cycle scientist as well as a participant in the Global Carbon Project, presented some unsettling findings about current global carbon emissions. He answered Scitizen's questions.

This column summarizes a set of conclusions that have been reached on the Climate Science weblog. Among the most significant is that the IPCC climate change assessments have been too conservative in recognizing the importance of a diverse range of human climate forcings, as identified in a 2005 National Research Council Report, as they alter regional and global climate. As a result, attempts to significantly influence regional and local-scale climate based on controlling CO2 emissions alone is an inadequate policy for this purpose.

Duchenne muscular dystrophy is a genetic disease that has not treatment and severely limits motility and life expectancy in people. A close animal model with the same symptoms as humans is the golden retriever dog. A recent study shows that stem cells injected into arteries have been able to help dogs with muscular dystrophy walk more normally. This can mean a possible future therapy for Duchenne muscular dystrophy patients.

The core finding of this study and of a companion study by the laboratory of Stuart Orkin at Children's Hospital essentially points to a paradigm for generating multiple different cell types in the heart from a stem cell-based model, as opposed to a model where all these different heart cell lineages come from distinct locations in separate embryonic precursors. There is a master cardiovascular progenitor cell with the function to form the three different cell types of the heart. It is essentially the ancestor of the previously reported islet progenitor that exists in the neo-natal heart of mice, rats, and humans.

Since H5N1 highly pathogenic avian influenza was first isolated from poultry in China in 1996, this disease has been shown to be spread by infected poultry, the trade of wild birds and recently, short distances through wild birds. In last week’s BioScience journal (06 Nov 2006), four avian ecologists published an article showing how simple, but detailed ecological and ornithological data, collected in a standardised way, at wild bird outbreaks can significantly improve our ability to understand the ecology of this disease in wild bird populations.

No one knows when the next influenza pandemic will happen. But the odds of it happening in the near future are shortening. H5N1 influenza, an avian influenza of considerable pathogenicity, was first isolated from a farm goose in China in 1996. By mid-November 2006, 258 cases had been reported among humans around the world, and of these, 153 had died. H5N1 has a high case fatality rate among humans, but there have been as yet no confirmed cases of the virus spreading between humans. To do this, the virus would have to undergo genetic reassortment to make it highly transmissible between humans, as well as pathogenic to them - although the case fatality rate will be less than case fatality rates reported for avian influenza. We may be waiting for the disaster that never comes. But wisdom lies in preparing, and so governments around the world have begun to plan for and develop test plans for pandemic response by health services.

Fourteen top international scientists in the field of nanotechnology have identified Five Grand Challenges for nanotechnology risk research that must be met if the technology is to reach its full potential. The study will be published Thursday November 16 in Nature. Dr. Martin Philbert, co-author of the paper, answers Scitizen’s questions.

What happens if you overheat vegetable oil or sugar in your kitchen? Vegetable oil smokes and turns brown and sugar turns black. Both of these are caused by decomposition because oil and sugar will not evaporate, so they decompose to form carbon. Schmidt and his students have found that, if you heat vegetable oil or sugar approximately one million times faster than you can do in your kitchen, they form no carbon at all, but rather form hydrogen and carbon monoxide. This gas mixture is called synthesis gas because it can be used to synthesize interesting fuels and chemicals such as synthetic gasoline. Since the mixture can be formed from biomass, this process can produce completely renewable fuels and chemicals. This is the basis of a paper recently published in Science magazine.

The advanced capabilities of many materials result from their exceptional surface properties. While coatings and paints improve surface properties through composition changes, some property improvements can also be achieved by changing the shape of the surface. One can cite many familiar examples: treaded tires for better traction, roughened windows for reducing transparency, and grooved records for reproducing sound. Notice that in each example, the choice of material is not critical. Windows can be made from glass or plastic, records can be made from wax or vinyl, etc. What makes this concept so powerful is the fact that dramatic improvements can be obtained from existing materials solely through the control of shape.