Science by Email 2 March 2012

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	2 March 2012
News: One step closer to polio eradication By Patrick Mahony Administering a polio vaccine. The World Health Organisation recently announced that India has gone for more than one year with no new cases of polio. Polio is a highly contagious viral disease often spread through contaminated drinking water. Most people who contract poliovirus show no symptoms, but in a small percentage of cases, the effects can be devastating. Once it is in the body, it can attack the nervous system, causing irreversible paralysis. In some extreme cases, the muscles responsible for breathing fail, leading to death. Polio used to be more common, but improved sanitation and the invention of a vaccine led to a decrease in cases in the developed world, although it remained a problem in the developing world. In 1988 the Global Polio Eradication Initiative was launched. Since then the number of cases has dropped from around 350 000 to less than 1500. India was one of only four countries where polio was endemic – that is, a country where polio has never been eradicated. Until recently, there were more polio cases in India than the other three endemic countries combined. A concerted vaccination program combined with improving water sanitation is believed to be responsible for this result. If there are no new cases reported for three years, India will have won the fight to be certified as having eradicated polio. More information World Health Organisation: Poliomyelitis Careers link What is an immunologist?
You will need these materials.   Carefully cut a few holes in the foam bowl.   Place the foam bowl inside the other, and add 5 of each kind of nut. Cover the foam bowl with a plate and shake over the other bowl for 5 seconds. For every nut still in the foam bowl, add another nut of the same kind. Repeat twice, shaking for 10 seconds and then 20 seconds.   Try this: Shake up antibiotic resistance You will need 5 different kinds of nuts (for example walnuts, brazil nuts, peanuts, cashews, macadamias) Scissors Foam bowl Another bowl Plate to cover the foam bowl What to do Use the scissors to carefully make a few holes in the bottom of the foam bowl. The holes should be big enough to allow some of the nuts to fall through, but not too easily. Place the foam bowl inside the other bowl, and place 5 of each kind of nut into the bowl. Cover the foam bowl with the plate and shake the foam bowl over the other for about 5 seconds. Some nuts should fall into the second bowl. Remove the plate and count how many of each type of nut is left in the foam bowl. For every nut left in the bowl, add another of the same type. For example, if there are 3 walnuts left, add another 3 walnuts to the bowl. Repeat steps 3 and 4, only this time shake the bowl for about 10 seconds. Repeat again, shaking the bowl for 20 seconds. Count the number and type of nuts left in the foam bowl. What’s happening? This activity models microbial resistance to antibiotics. The holes in the foam bowl represent antibiotic action. Microbes are represented by the nuts – they ‘die’ if they fall through the holes. The different-sized nuts represent varying levels of resistance to antibiotics: the larger the nut, the more resistant the microbe. Microbes that aren’t killed by antibiotics are able to reproduce. This is why the extra nuts are added after each shaking. After 3 shakings, the weak microbes have mostly died out leaving behind the stronger, more resistant microbes behind. Applications Some strains of microbes have become so resistant that a number of antibiotics no longer work on them at all. Such microbes are called ‘superbugs’. Superbugs are a real problem in hospitals where they can spread rapidly and be difficult to treat. Problems arising from antibiotic resistance can be minimised by only using antibiotics when they are really necessary and fully completing any course of antibiotics that you are prescribed. By Patrick Mahony Try another Science by Email activity about diseases More information World Health Organisation View the online version Quiz questions 1. What was the main cause of the extinction of the thylacine in Tasmania? 2. Most metallic elements are what colour? 3. In what part of the body would find the cornea, retina and vitreous humour? 4. What is measured in m/s2? 5. Is the oldest known dinosaur nest 130, 160 or 190 million years old? Did you know? The male great bowerbird uses optical illusions to attract a mate. Websites See it! Check out these images of sand dunes on Mars. Do it! Explore what conditions affect glaciers in this simulation. Future Sparks How will we power up the planet in the future? Algae-fuelled planes? Or compost combustors? Do you have an even better idea? Make a video or write it down and enter Future Sparks, one of the biggest science competitions of the year! Events Victoria: Science Talent Search The Science Talent Search is open to all primary and secondary students in Victoria. This year’s theme is ‘Sustainability and our environment’, and there are heaps of competitions, including creative writing, experimental work, games and photography. Entries open on Monday 5 March. For full details, head over to the Science Talent Search website. Clothing science, Saturday 3 March at 7.30 am on Network Ten How do you turn the fruit of cotton plants into a cotton shirt? What is warmer: multiple layers of t-shirts or one woolly jumper? Are self-cleaning clothes possible? To find out all these answers and more, join Dr Rob as he once again proves that the ordinary becomes extraordinary, under the SCOPE. Next episodes: Thursday 8 March: Aquatic animals Saturday 10 March: Experiment special Want to have your own episodes of SCOPE to watch whenever you feel like it? Click here to download them directly into your iTunes folder, or go here to download iTunes. Charges apply. Quiz answers 1. The thylacine was hunted to extinction by humans as it was believed to be a pest. 2. Most metallic elements are grey in colour. 3. The cornea, retina and vitreous humour are all found in the eye. 4. Acceleration is measured in m/s2. 5. The oldest known dinosaur nest is approximately 190 million years old. It was found in South Africa and belonged to Massospondylus. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editor: Jasmine Leong | Manage your subscription | FAQ

 

 

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