Science Spin 48 September 2011 | Page 4

Dead end UPFRONT www.sciencespin.com Evolution does not always lead to greater complexity, and parasites often shed the ancestral traits that enabled them to survive in the past. Powdery mildew is one example, and researchers from the Max Planck institute for Plant Breeding Research in Cologne found that this pathogen has whittled its gene count down to just 6,000. Powdery mildew cannot fix nitrogen, it cannot harness energy through fermentation, and it cannot produce metabolic products that would enable it to survive without the help of a host plant. According to the researchers, Powdery Mildew lacks 99 genes that enable bakers’ yeast to lead an independent existence. Because it gets virtually everything it needs from the host, the powdery mildew fungus had no need to retain these genes, but that also meant it was trapped into an evolutionary dead end. this does not mean that the organism is a failure. its simplicity means that it offers few targets for the host’s defensive system to attack, and as a highly successful parasite it can destroy entire harvests. one of the peculiarities of this fungus is that, in spite of its relatively low number of genes, it has almost Powdery mildew on a barley leaf. Photo: Anja Reinstädler. 120 million base pairs. one of the researchers, Ralph Panstruga, explained that this big number is due to resorting and jumbling up of genetic material, due to the activities of ‘jumping genes’. Plant hunters and sheep eaters tAkE a tour around the national Botanic Gardens without leaving home, or walk around the plants with your own personal guide. Choose an iPhone app or MP3 version for a commentary that helps you discover what’s so special in the Gardens. Broadcaster, Mary Mulvihill, with Garden Director, Matthew Jebb, orchid expert Brendan Sayers, and wildlife guide, Glynn Anderson have produced this free guide. the guide has three 40 minute tours, so you can choose the glasshouses for rainy days, a stroll around the gardens, or a walk by riverside wildlife. to download the guide go to: www.ingeniousireland or LIVE www.botanicgardens.ie LINK This Summer all the elements are on show at the TCD Science Gallery. How much nickel do you have? See some of the wallpaper that made people ill, Sue McGrath shows kids how to make up a chemical mix, and learn how Mendeleev made up the Periodic Table. Exhibition ends 30th September 2011. LIVE www.sciencegallery.com LINK Elements thE MothER of an autistic girl found that little picture cards are a help in breaking the communication barrier. however, cards can get damaged or lost, so one day she spotted an advertisement for an iPhone, and saw that this could provide an ideal solution to this and other problems. the mother, lisa Domican, explained that with less than one hour a week of speech therapy being provided by the hSE for an entire class of children with severe autism, her daughter lisa, was simply not getting enough attention. “it was up to me to teach her to communicate so i did the parents course and set up the picture exchange system myself. it was hard work but i stuck with it. they told me that she would never talk, but Gracie can now speak in three word sentences using the app and her independence grows each day - we proved them wrong.” the app, supported by o2, telefonica and irish Autism Action was developed with a games creator, Steven troughton-Smith, and since its launch on itunes, there have been thousands of downloads, and lisa has received many requests for translation into different languages. Non-verbal communications SCIENCE SPIN Issue 48 Page 2